JP7778581B2 - Drive unit for human-powered vehicles - Google Patents

Description

This disclosure relates to a drive unit for a human-powered vehicle.

For example, Patent Document 1 discloses a drive unit for a human-powered vehicle that includes a transmission connected to a motor. The transmission of the drive unit for a human-powered vehicle in Patent Document 1 includes a reducer composed of multiple sprockets and multiple chains.

International Publication No. 2011/013109

One of the objectives of this disclosure is to provide a drive unit for a human-powered vehicle that allows for greater design freedom.

A drive unit according to a first aspect of the present disclosure is a drive unit for a human-powered vehicle, comprising: a housing; an input section provided in the housing and configured to input a driving force; a first transmission section provided in the housing and configured to input the driving force via the input section; and an output section provided in the housing, configured to be rotatable, and to input the driving force via the first transmission section, wherein the first transmission section includes a first input rotor, a first output rotor having a different diameter from the first input rotor, and a first endless annular member wound around the first input rotor and the first output rotor, wherein the first endless annular member engages with the first input rotor and the first output rotor, respectively, and includes a plurality of first engaging sections having a first pitch width in the extension direction of the first endless annular member, the first pitch width being 4 mm or more and 10 mm or less.
According to the drive unit of the first aspect, the first pitch width of the first endless annular member is 4 mm or more and 10 mm or less, so the first endless annular member can be made smaller, thereby improving the degree of freedom in design.

In the drive unit of the second aspect according to the first aspect of the present disclosure, the first pitch width is equal to or greater than 5 mm and equal to or less than 8 mm.
According to the drive unit of the second aspect, the first pitch width is not less than 5 mm and not more than 8 mm, so that the first endless annular member can be suitably miniaturized.

In the drive unit of a third aspect according to the first or second aspect of the present disclosure, the first transmission portion constitutes a reducer.
According to the drive unit of the third aspect, the first transmission can decelerate the vehicle speed appropriately.

A drive unit of a fourth aspect according to any one of the first to third aspects of the present disclosure further includes a second transmission unit provided in the housing and receiving the driving force via the first transmission unit, the driving force being input to the output unit via the second transmission unit, the second transmission unit including a second input rotor, a second output rotor having a different diameter than the second input rotor, and a second endless annular member wound around the second input rotor and the second output rotor, the second endless annular member engaging with the second input rotor and the second output rotor, respectively, and including a plurality of second engaging portions having a second pitch width in the direction of extension of the second endless annular member, the second pitch width being 4 mm or more and 10 mm or less.
According to the drive unit of the fourth aspect, since the second pitch width is 4 mm or more and 10 mm or less, the second endless annular member can suitably transmit driving force between the second input rotor and the second output rotor.

In the drive unit of the fifth aspect according to the fourth aspect of the present disclosure, the second pitch width is equal to or greater than 5 mm and equal to or less than 8 mm.
According to the drive unit of the fifth aspect, the second pitch width of the second endless annular member is 5 mm or more and 8 mm or less, so that the second endless annular member can be made smaller, thereby further improving the degree of freedom in design.

In the drive unit of a sixth aspect according to the fourth or fifth aspect of the present disclosure, the second transmission portion constitutes a reducer.
According to the drive unit of the sixth aspect, the second transmission can decelerate the vehicle speed appropriately.

In a drive unit of a seventh aspect according to any one of the fourth to sixth aspects of the present disclosure, the first input rotation center axis of the first input rotor, the first output rotation center axis of the first output rotor, the second input rotation center axis of the second input rotor, and the second output rotation center axis of the second output rotor are arranged substantially parallel to a first direction, and the first output rotor is offset relative to the second input rotor in the first direction and arranged coaxially with the second input rotor.
According to the drive unit of the seventh aspect, the first output rotor and the second input rotor are arranged side by side in the first direction, so that the dimensions of the drive unit can be reduced in a direction perpendicular to the first direction.

In the drive unit of an eighth aspect according to the seventh aspect of the present disclosure, the second transmission portion is disposed between the first transmission portion and the output portion in the first direction.
According to the drive unit of the eighth aspect, the driving force can be suitably input from the first transmission section to the second transmission section.

In a drive unit of a ninth aspect according to any one of the first to eighth aspects of the present disclosure, the first input rotor includes a first sprocket, the first output rotor includes a second sprocket, and the first endless annular member includes a chain.
According to the drive unit of the ninth aspect, the speed can be suitably changed by the first speed change section including the first sprocket, the second sprocket, and the chain.

In a drive unit of a tenth aspect according to any one of the first to eighth aspects of the present disclosure, the first input rotor includes a first pulley, the first output rotor includes a second pulley, and the first endless annular member includes a belt.
According to the drive unit of the tenth aspect, the speed can be suitably changed by the first transmission unit including the first pulley, the second pulley, and the belt.

In a drive unit of an eleventh aspect according to any one of the first to tenth aspects of the present disclosure, a first one-way clutch is further provided, and the first one-way clutch is arranged in a transmission path of the driving force between the input portion and the output portion.
According to the drive unit of the eleventh aspect, it is possible to suppress input of driving force from the output portion to the input portion.

In a drive unit of a twelfth aspect according to any one of the first to eleventh aspects of the present disclosure, an input rotating shaft is provided in the housing and into which a manual driving force is input, and the input rotation central axis of the input rotating shaft is arranged coaxially with the output rotation central axis of the output section.
According to the drive unit of the twelfth aspect, the degree of freedom in designing a drive unit having an input rotation shaft can be improved.

In the drive unit of the thirteenth aspect according to the twelfth aspect of the present disclosure, at least a portion of the input rotating shaft is accommodated in the housing, and at least a portion of the input rotating shaft accommodated in the housing has a length in the axial direction of the input rotating shaft of 50 mm or more and 70 mm or less.
According to the drive unit of the thirteenth aspect, for example, when crank arms are connected to both ends of the input rotary shaft, the distance between the crank arms can be shortened.

In the drive unit of the fourteenth aspect according to the twelfth or thirteenth aspect of the present disclosure, a second one-way clutch is further provided, and the second one-way clutch is disposed between the input rotating shaft and the output part in the transmission path of the manual driving force.
According to the drive unit of the fourteenth aspect, it is possible to suppress input of driving force from the output portion to the input rotation shaft.

The drive unit for a human-powered vehicle disclosed herein allows for greater design freedom.

1 is a perspective view of a drive unit for a human-powered vehicle according to a first embodiment. FIG. 2 is a first side view of the drive unit for the human-powered vehicle of FIG. 1; FIG. 2 is a second side view of the drive unit for the human-powered vehicle of FIG. 1 . FIG . 4 is a diagram showing the arrangement of the reducer inside the housing, with the second housing omitted from FIG. 3 . FIG . 3 is a diagram showing the arrangement of the reducer inside the housing, with the first housing omitted from FIG. 2 . 6 is a schematic diagram of the inside of a drive unit for a human-powered vehicle, viewed in the direction of arrow V, with the housing cut along line D6-D6 in FIG. 2. FIG. 7 is a schematic diagram showing the motor, the reducer, the input rotating shaft, and the output section of FIG. 6 . FIG. 8 is a schematic diagram showing the intermediate shaft, the first rotating member, the third rotating member, and the surrounding areas of ... third rotating member shown in FIG. 7 . FIG. 7 is a schematic diagram showing a cross-sectional structure of the input rotating shaft, the output portion, the first one-way clutch, and the surrounding areas in FIG. 6 . FIG. 2 is a plan view of a first chain according to the first embodiment. FIG. 11 is a side view of the first chain of FIG. 10 . FIG. 4 is a plan view of a second chain in the first embodiment. FIG. 13 is a side view of the second chain of FIG. 12. FIG. 10 is a schematic diagram showing a first pitch width of a first belt in a second embodiment. FIG. 10 is a schematic diagram showing a second pitch width of a second belt in a second embodiment. FIG. 11 is a schematic diagram showing transmission paths of the driving force of the motor and the human-powered driving force in a drive unit for a human-powered vehicle according to a third embodiment. FIG. 10 is a first schematic diagram showing the arrangement of a reducer according to a first modified example. FIG. 10 is a second schematic diagram showing the arrangement of the reducer in the first modified example. FIG. 10 is a schematic diagram showing a motor, a reducer, an input rotating shaft, and an output section of a second modified example. FIG. 10 is a schematic diagram showing an intermediate shaft, a first rotating member, a third rotating member, and their surroundings in a third modified example.

First Embodiment
A drive unit 10 for a human-powered vehicle will be described with reference to FIGS. 1 to 13. Hereinafter, the drive unit 10 for a human-powered vehicle will be simply referred to as the drive unit 10. A human-powered vehicle is a vehicle that has at least one wheel and can be propelled at least by human driving force. Human-powered vehicles include various types of bicycles, such as mountain bikes, road bikes, city bikes, cargo bikes, hand bikes, and recumbent bikes. The number of wheels a human-powered vehicle has is not limited. Human-powered vehicles also include, for example, unicycles and vehicles with two or more wheels. Human-powered vehicles are not limited to vehicles that can be propelled solely by human driving force. Human-powered vehicles include E-bikes that use not only human driving force but also the driving force of an electric motor for propulsion. E-bikes include electrically assisted bicycles whose propulsion is assisted by an electric motor. In the following embodiments, the human-powered vehicle will be described as an electrically assisted bicycle.

For example, a human-powered vehicle includes a crank to which human-powered driving force is input, wheels, and a vehicle body. For example, the wheels include a rear wheel and a front wheel. For example, the vehicle body includes a frame, a front fork, a handlebar, and a stem. The vehicle body may further include at least one of a suspension and a carrier. The front wheel is attached to the frame via the front fork. The handlebar is connected to the front fork via the stem. The rear wheel is driven by rotation of the crank. The rear wheel is supported by the frame.

For example, a human-powered vehicle includes an input rotating shaft 12 that can rotate relative to the frame. Human-powered driving force is input to the input rotating shaft 12. The input rotating shaft 12 is configured to rotate by the input human-powered driving force. The crank is made up of the input rotating shaft 12 and crank arms provided at the axial ends of the input rotating shaft 12. Pedals are connected to each crank arm. In this embodiment, the input rotating shaft 12 is a crankshaft.

The crank is connected to the rear wheel by a drive mechanism. The drive mechanism includes a first drive rotor, a second drive rotor, and a connecting member. The first drive rotor is connected to the input rotary shaft 12. The first drive rotor includes a sprocket, pulley, or bevel gear. The first drive rotor rotates in correspondence with the input rotary shaft 12. The second drive rotor is connected to the rear wheel. The second drive rotor includes a sprocket, pulley, or bevel gear. The connecting member transmits the rotational force of the first drive rotor to the second drive rotor. The connecting member includes, for example, a chain, belt, or shaft.

A one-way clutch is provided between the second driving rotor and the rear wheel. The one-way clutch is configured to rotate the rear wheel forward when the second driving rotor rotates forward, and to allow relative rotation between the second driving rotor and the rear wheel when the second driving rotor rotates backward. In this embodiment, the rear wheel is connected to the crank by a drive mechanism. At least one of the rear wheel and the front wheel may be connected to the crank by a drive mechanism.

For example, the human-powered vehicle includes a battery. The battery is disposed on at least one of the frame of the human-powered vehicle and the carrier of the human-powered vehicle. For example, the battery includes one or more battery elements. For example, the battery element includes a rechargeable battery. For example, the battery is configured to supply power to the drive unit 10. For example, the battery is communicatively connected to the drive unit 10 via a wired or wireless connection. The battery can communicate with the drive unit 10 via, for example, power line communication (PLC), a controller area network (CAN), or a universal asynchronous receiver/transmitter (UART).

The drive unit 10 includes a housing 14. For example, the housing 14 includes a first housing 14A and a second housing 14B. The first housing 14A and the second housing 14B are arranged side by side in the axial direction of the input rotary shaft 12 and form an internal space SA. For example, the drive unit 10 includes the input rotary shaft 12. For example, the housing 14 includes at least one mounting portion 14C. The housing 14 is detachably attached to the frame of the human-powered vehicle by the at least one mounting portion 14C. The at least one mounting portion 14C is provided on the housing 14 and is configured to be attached to the frame of the human-powered vehicle. For example, the at least one mounting portion 14C includes a female thread, and a screw member including a male thread is screwed into the at least one mounting portion 14C, thereby attaching the housing 14 to the frame of the human-powered vehicle.

For example, the first housing 14A and the second housing 14B are connected to each other by a connecting member 14D. The connecting member 14D is, for example, a bolt or a rivet. One of the first housing 14A and the second housing 14B is provided with a through-hole into which the shank of a bolt is inserted, for example, and the other of the first housing 14A and the second housing 14B is provided with a female thread portion that engages with the bolt, for example.

For example, the drive unit 10 further includes a motor 16 configured to provide propulsive force to the human-powered vehicle. For example, the motor 16 is disposed in the interior space SA of the housing 14. For example, the motor 16 includes a rotor 16A and a stator 16B. For example, the motor 16 is configured such that the rotor 16A rotates when power is supplied from the battery of the human-powered vehicle.

The motor 16 is provided in the housing 14 and is configured to provide propulsive force to the human-powered vehicle. For example, the motor 16 includes a motor output shaft 18. For example, the drive unit 10 includes a first bearing 20, and the motor output shaft 18 is supported on the housing 14 via the first bearing 20. For example, the first bearing 20 may be a ball bearing, a roller bearing, or a plain bearing.

For example, the motor 16 includes a rotation mechanism 16X including a rotor 16A and a stator 16B, and a motor output shaft 18. For example, the rotation mechanism 16X is configured to be circular when viewed from the first direction X1. For example, the rotor 16A is disposed inside the stator 16B. For example, the motor 16 is an inner rotor type motor. For example, the rotor 16A is configured to rotate when power is supplied to the stator 16B. For example, the motor output shaft 18 is connected to the rotor 16A and configured to rotate integrally with the rotor 16A. For example, in the first direction X1, the motor output shaft 18 is configured to extend from the inside to the outside of the rotor 16A. For example, the motor rotation center axis C1 of the motor output shaft 18 is aligned with the rotation center axis of the rotor 16A. The motor 16 may be an outer rotor type motor or an axial gap type motor.

For example, the drive unit 10 includes a control unit that controls the motor 16. The control unit includes a processing unit that executes a predetermined control program. The processing unit includes, for example, a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). The control unit may include one or more microcomputers. The control unit may include multiple processing units located at multiple separate locations. For example, the control unit further includes a memory unit. The memory unit stores various control programs and information used for various control processes. The memory unit includes, for example, non-volatile memory and volatile memory. Non-volatile memory includes, for example, at least one of ROM (Read-Only Memory), EPROM (Erasable Programmable Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), and flash memory. Volatile memory includes, for example, RAM (Random Access Memory).

For example, at least a portion of the control unit is mounted on a first circuit board disposed in the internal space SA. For example, the control unit includes an inverter circuit that supplies power to the motor 16. For example, the inverter circuit is mounted on the first circuit board. The control unit is configured to control the motor 16 by controlling the power supplied from the inverter circuit to the motor 16.

For example, the drive unit 10 further includes an input section 22. For example, the input section 22 is provided in the housing 14 and configured to receive a driving force. For example, the input section 22 is configured to receive a driving force from the motor 16. For example, the input section 22 inputs the driving force of the motor 16 to the reducer 24. For example, the input section 22 includes the motor output shaft 18.

For example, the drive unit 10 further includes an output section 26. For example, the output section 26 is provided in the housing 14, configured to be rotatable, and receives driving force via the reducer 24. For example, the output section 26 is connected to the first drive rotor and configured to rotate integrally with the first drive rotor. For example, the output section 26 is configured to output at least one of the driving force of the motor 16 and the manual driving force input to the input rotary shaft 12 to the first drive rotor as propulsion force for the human-powered vehicle. In this embodiment, the output section 26 is configured to output a driving force that is a combination of the driving force of the motor 16 and the manual driving force input to the input rotary shaft 12 to the first drive rotor.

For example, at least a portion of the output portion 26 is housed in the internal space SA of the housing 14. For example, a first hole 14X is formed in the housing 14. For example, the drive unit 10 includes a second bearing 28, and the output portion 26 is supported in the first hole 14X of the housing 14 via the second bearing 28. For example, the second bearing 28 may be a ball bearing, a roller bearing, or a plain bearing. For example, the output portion 26 includes a connecting portion 26A disposed outside the housing 14. For example, if splines are formed on the inner peripheral surface of the first drive rotor, splines that engage with the splines of the first drive rotor are formed on the outer peripheral surface of the connecting portion 26A.

For example, the drive unit 10 further includes a first one-way clutch 30. For example, the first one-way clutch 30 is disposed in the driving force transmission path between the input section 22 and the output section 26. For example, the first one-way clutch 30 is disposed so as to suppress transmission of the rotational force of the output section 26 to the motor 16 when the rotation direction of the output section 26 corresponds to the direction opposite to the forward movement of the human-powered vehicle. For example, the first one-way clutch 30 is housed in the internal space SA of the housing 14. For example, the first one-way clutch 30 includes one of a roller clutch, a pawl ratchet clutch, and a sprag clutch.

For example, the first one-way clutch 30 is disposed at the connection between the reducer 24 and the output section 26. For example, the first one-way clutch 30 includes an inner ring, an outer ring, and an engaging member disposed between the inner ring and the outer ring. For example, if the first one-way clutch 30 includes a roller clutch, the engaging member includes a rolling element. For example, the rotational axis of the first one-way clutch 30 is arranged coaxially with the output section rotational axis C2 of the output section 26. For example, the inner ring of the first one-way clutch 30 is configured to rotate integrally with the output section 26. For example, the inner ring of the first one-way clutch 30 is arranged on the outer periphery of the output section 26. The inner ring of the first one-way clutch 30 may be press-fitted into the output section 26 or may be formed integrally with the output section 26. For example, the outer ring of the first one-way clutch 30 is arranged on the inner periphery of a rotating body included in the reducer 24. For example, the outer ring of the first one-way clutch 30 is configured to rotate integrally with the rotating body included in the reducer 24.

For example, the drive unit 10 further includes an input rotating shaft 12 that is provided in the housing 14 and receives manual driving force. For example, the housing 14 is formed with a second hole 14Y that faces the first hole 14X in the axial direction of the input rotating shaft 12. For example, the drive unit 10 includes a third bearing 32, and the input rotating shaft 12 is supported in the second hole 14Y of the housing 14 via the third bearing 32. For example, the third bearing 32 may be a ball bearing, a roller bearing, or a plain bearing.

For example, the input rotation center axis C3 of the input rotating shaft 12 is arranged coaxially with the output rotation center axis C2 of the output section 26. For example, the input rotating shaft 12 is configured to rotate integrally with the output section 26 when a human-powered driving force in the direction in which the human-powered vehicle moves forward is input to the input rotating shaft 12. For example, the input rotating shaft 12 is supported in the first hole 14X of the housing 14 via the output section 26.

For example, at least a portion of the input rotation shaft 12 is accommodated in the housing 14. In this embodiment, the portion of the input rotation shaft 12 on which part of the reducer 24 is provided is accommodated in the housing 14. For example, at least a portion of the input rotation shaft 12 accommodated in the housing 14 has a length L in the axial direction of the input rotation shaft 12 of 50 mm or more and 70 mm or less. For example, at least a portion of the input rotation shaft 12 accommodated in the housing 14 has a length L in the axial direction of the input rotation shaft 12 of 55 mm or more and 65 mm or less. For example, the length in the axial direction of the input rotation shaft 12 of the portion of the housing 14 where the input rotation shaft 12 is disposed is substantially equal to the length L.

For example, at least a portion of the input rotation shaft 12 is disposed between the first plane A1 and the second plane A2. For example, the first plane A1 is a plane that includes the first end face B1 of the rotation mechanism unit 16X in the first direction X1, which is substantially parallel to the motor rotation central axis C1 of the motor output shaft 18, and is perpendicular to the first direction X1. For example, the first end face B1 is the end face of the rotation mechanism unit 16X in the first direction X1 on the side from which the motor output shaft 18 protrudes. For example, the second plane A2 is a plane that includes the second end face B2 of the rotation mechanism unit 16X in the first direction X1, and is perpendicular to the first direction X1. For example, the second end face B2 is the end face opposite the first end face B1 in the first direction X1.

For example, the drive unit 10 further includes a second one-way clutch 34. For example, the second one-way clutch 34 is disposed between the input rotary shaft 12 and the output section 26 in the transmission path of the human-powered driving force. For example, the second one-way clutch 34 is configured so that when the input rotary shaft 12 rotates in a first rotational direction corresponding to the forward direction of the human-powered vehicle, the driving force of the input rotary shaft 12 is transmitted to the output section 26, but the rotation of the output section 26 is not transmitted to the input rotary shaft 12. For example, the second one-way clutch 34 is configured so that when the input rotary shaft 12 rotates in the first rotational direction, the driving force of the input rotary shaft 12 is transmitted to the output section 26, but when the input rotary shaft 12 rotates in a second rotational direction opposite to the first rotational direction, the driving force of the input rotary shaft 12 is not transmitted to the output section 26. For example, the second one-way clutch 34 is housed in the internal space SA of the housing 14. For example, the second one-way clutch 34 includes one of a roller clutch, a pawl ratchet clutch, and a sprag clutch.

For example, the second one-way clutch 34 is disposed between the outer periphery of the input rotary shaft 12 and the inner periphery of the output section 26. For example, the second one-way clutch 34 includes an inner ring, an outer ring, and an engaging member disposed between the inner ring and the outer ring. For example, if the second one-way clutch 34 includes a roller clutch, the engaging member includes a rolling element. For example, the rotational axis of the second one-way clutch 34 is arranged coaxially with the output section rotational axis C2 of the output section 26. For example, the inner ring of the second one-way clutch 34 is configured to rotate integrally with the input rotary shaft 12. For example, the inner ring of the second one-way clutch 34 is arranged on the outer periphery of the input rotary shaft 12. For example, the inner ring of the second one-way clutch 34 may be formed integrally with the outer periphery of the input rotary shaft 12 or may be press-fitted to the outer periphery of the input rotary shaft 12. For example, the outer ring of the second one-way clutch 34 is configured to rotate integrally with the output section 26. For example, the outer ring of the second one-way clutch 34 may be formed integrally with the inner periphery of the output portion 26, or may be press-fitted into the inner periphery of the output portion 26.

For example, the reducer 24 is provided in the housing 14 and receives the driving force from the motor 16. For example, the reducer 24 is at least partially housed in the internal space SA of the housing 14. For example, the reducer 24 is entirely housed in the internal space SA of the housing 14. For example, the reducer 24 reduces the input rotational speed and outputs it. For example, the reducer 24 is connected to the motor output shaft 18 and also to the output section 26. For example, the reducer 24 outputs the driving force of the motor 16 input to the input section 22 from the output section 26.

For example, the reducer 24 includes multiple transmissions. For example, one transmission includes a reduction mechanism that performs one-stage reduction. For example, the reducer 24 reduces and outputs the input rotational speed in stages corresponding to the number of transmissions included in the reducer 24. For example, the reducer 24 includes an intermediate shaft 36, a first transmission 38, a second transmission 40, a third transmission 42, and a fourth transmission 44. For example, at least one of the first transmission 38, the second transmission 40, the third transmission 42, and the fourth transmission 44 includes a predetermined reducer. The predetermined reducer includes at least one of a chain-type reducer and a belt-type reducer. In this embodiment, the first transmission 38, the second transmission 40, the third transmission 42, and the fourth transmission 44 each include a predetermined reducer.

For example, driving force is input from the input unit 22 to the output unit 26 via the reducer 24. For example, the driving force of the input unit 22 is transmitted in the order of the first transmission 38, the second transmission 40, the third transmission 42, and the fourth transmission 44, and is output from the fourth transmission 44 to the output unit 26.

For example, at least one of a portion of the first transmission 38, a portion of the second transmission 40, a portion of the third transmission 42, and a portion of the fourth transmission 44 is disposed on the intermediate shaft 36. For example, the intermediate shaft 36 is disposed in the internal space SA of the housing 14 so that its central axis is disposed substantially parallel to the first direction X1. For example, the intermediate shaft 36 is disposed offset from the motor output shaft 18 and the output portion 26 in a direction perpendicular to the first direction X1, and disposed substantially parallel to the motor output shaft 18. For example, both ends of the intermediate shaft 36 in the first direction X1 are supported by the housing 14.

For example, the first transmission 38 is disposed in the internal space SA of the housing 14 and is provided in the housing 14. For example, the first transmission 38 includes an input rotor 38A, an output rotor 38B, and an endless annular member 38C. If the first transmission 38 includes a chain-type reducer, the input rotor 38A and the output rotor 38B include sprockets, and the endless annular member 38C includes a chain. If the first transmission 38 includes a belt-type reducer, the input rotor 38A and the output rotor 38B include pulleys, and the endless annular member 38C includes a belt. In this embodiment, the first transmission 38 includes a chain-type reducer. For example, the first transmission 38 changes the rotational speed of the input rotor 38A to rotate the output rotor 38B. The input rotor 38A is disposed coaxially with the motor output shaft 18 and is a rotor to which driving force is input from the motor 16. For example, the input rotor 38A is provided on the outer peripheral surface of the motor output shaft 18 and is configured to rotate integrally with the motor output shaft 18.

The output rotor 38B has a different diameter from the input rotor 38A and is mounted on the intermediate shaft 36. For example, the diameter of the output rotor 38B is larger than the diameter of the input rotor 38A. For example, the output rotor 38B is disposed on the outer circumferential surface of the intermediate shaft 36 and is configured to be rotatable relative to the intermediate shaft 36. The endless annular member 38C is a member that is wrapped around the input rotor 38A and the output rotor 38B. The input rotor 38A and the output rotor 38B are connected by the endless annular member 38C so that they rotate together.

For example, the endless annular member 38C engages with the input rotor 38A and the output rotor 38B, respectively, and includes multiple engagement portions in the direction in which the endless annular member 38C extends. For example, the multiple engagement portions are arranged side by side at a predetermined pitch width. For example, the input rotor 38A and the output rotor 38B include teeth that engage with the multiple engagement portions. The dimension of the teeth of the input rotor 38A in a direction parallel to the motor rotational center axis C1 is smaller than the dimension in the radial direction of the motor rotational center axis C1. The dimension of the teeth of the output rotor 38B in a direction parallel to the intermediate shaft center axis C4 is smaller than the dimension in the radial direction of the intermediate shaft center axis C4.

For example, the second transmission 40 is disposed in the internal space SA of the housing 14 and is provided in the housing 14. For example, the second transmission 40 includes an input rotor 40A, an output rotor 40B, and an endless annular member 40C. If the second transmission 40 includes a chain-type reducer, the input rotor 40A and the output rotor 40B include sprockets, and the endless annular member 40C includes a chain. If the second transmission 40 includes a belt-type reducer, the input rotor 40A and the output rotor 40B include pulleys, and the endless annular member 40C includes a belt. In this embodiment, the second transmission 40 includes a chain-type reducer. For example, the second transmission 40 changes the rotational speed of the input rotor 40A to rotate the output rotor 40B. The input rotor 40A is provided coaxially with the intermediate shaft 36 and is a rotor to which driving force is input via the output rotor 38B. For example, the input rotor 40A is configured to rotate integrally with the output rotor 38B. For example, the input rotor 40A is disposed on the outer peripheral surface of the intermediate shaft 36 and is configured to be rotatable relative to the intermediate shaft 36.

The output rotor 40B has a different diameter from the input rotor 40A and is arranged coaxially with the output section 26. For example, the diameter of the output rotor 40B is larger than the diameter of the input rotor 40A. For example, the output rotor 40B is arranged on the outer peripheral surface of the input rotor shaft 12 and is configured to be rotatable relative to the input rotor shaft 12. The endless annular member 40C is a member that is wrapped around the input rotor 40A and the output rotor 40B. The input rotor 40A and the output rotor 40B are connected by the endless annular member 40C so that they rotate together.

For example, the endless annular member 40C engages with the input rotor 40A and the output rotor 40B, respectively, and includes multiple engagement portions in the direction in which the endless annular member 40C extends. For example, the multiple engagement portions are arranged side by side at a predetermined pitch width. For example, the input rotor 40A and the output rotor 40B include teeth that engage with the multiple engagement portions. The dimension of the teeth of the input rotor 40A in a direction parallel to the intermediate shaft central axis C4 is smaller than the dimension in the radial direction of the intermediate shaft central axis C4. The dimension of the teeth of the output rotor 40B in a direction parallel to the input rotation central axis C3 is smaller than the dimension in the radial direction of the input rotation central axis C3.

For example, the third transmission 42 is disposed in the internal space SA of the housing 14 and is provided in the housing 14. For example, the third transmission 42 includes an input rotor 42A, an output rotor 42B, and an endless annular member 42C. If the third transmission 42 includes a chain-type reducer, the input rotor 42A and the output rotor 42B include sprockets, and the endless annular member 42C includes a chain. If the third transmission 42 includes a belt-type reducer, the input rotor 42A and the output rotor 42B include pulleys, and the endless annular member 42C includes a belt. In this embodiment, the third transmission 42 includes a chain-type reducer. For example, the third transmission 42 changes the rotational speed of the input rotor 42A to rotate the output rotor 42B. The input rotor 42A is provided coaxially with the output section 26 and is a rotor to which driving force is input via the output rotor 40B. For example, the input rotor 42A is configured to rotate integrally with the output rotor 40B. For example, the input rotor 42A is disposed on the outer circumferential surface of the input rotary shaft 12 and is configured to be rotatable relative to the input rotary shaft 12.

The output rotor 42B has a different diameter from the input rotor 42A and is mounted on the intermediate shaft 36. For example, the diameter of the output rotor 42B is larger than the diameter of the input rotor 42A. For example, the output rotor 42B is disposed on the outer circumferential surface of the intermediate shaft 36 and is configured to be rotatable relative to the intermediate shaft 36. The endless annular member 42C is a member that is wrapped around the input rotor 42A and the output rotor 42B. The input rotor 42A and the output rotor 42B are connected by the endless annular member 42C so that they rotate together.

For example, the endless annular member 42C engages with the input rotor 42A and the output rotor 42B, respectively, and includes multiple engagement portions in the direction in which the endless annular member 42C extends. For example, the multiple engagement portions are arranged side by side at a predetermined pitch width. For example, the input rotor 42A and the output rotor 42B include teeth that engage with the multiple engagement portions. The dimension of the teeth of the input rotor 42A in a direction parallel to the input rotation center axis C3 is smaller than the dimension in the radial direction of the input rotation center axis C3. The dimension of the teeth of the output rotor 42B in a direction parallel to the intermediate shaft center axis C4 is smaller than the dimension in the radial direction of the intermediate shaft center axis C4.

For example, the fourth transmission 44 is disposed in the internal space SA of the housing 14 and is provided in the housing 14. For example, the fourth transmission 44 includes an input rotor 44A, an output rotor 44B, and an endless annular member 44C. If the fourth transmission 44 includes a chain-type reducer, the input rotor 44A and the output rotor 44B include sprockets, and the endless annular member 44C includes a chain. If the fourth transmission 44 includes a belt-type reducer, the input rotor 44A and the output rotor 44B include pulleys, and the endless annular member 44C includes a belt. In this embodiment, the fourth transmission 44 includes a chain-type reducer. For example, the fourth transmission 44 changes the rotational speed of the input rotor 44A to rotate the output rotor 44B. The input rotor 44A is provided on the intermediate shaft 36 and is a rotor to which driving force is input via the output rotor 42B. For example, the input rotor 44A is configured to rotate integrally with the output rotor 42B. For example, the input rotor 44A is disposed on the outer peripheral surface of the intermediate shaft 36 and is configured to be rotatable relative to the intermediate shaft 36.

The output rotor 44B has a different diameter than the input rotor 44A and is arranged coaxially with the output section 26. For example, the diameter of the output rotor 44B is larger than the diameter of the input rotor 44A. For example, the output rotor 44B is arranged on the outer circumferential surface of the output section 26 via the first one-way clutch 30. The endless annular member 44C is a member that is wrapped around the input rotor 44A and the output rotor 44B. The input rotor 44A and the output rotor 44B are connected by the endless annular member 44C so that they rotate together.

For example, the endless annular member 44C engages with the input rotor 44A and the output rotor 44B, respectively, and includes multiple engagement portions in the direction in which the endless annular member 44C extends. For example, the multiple engagement portions are arranged side by side at a predetermined pitch width. For example, the input rotor 44A and the output rotor 44B include teeth that engage with the multiple engagement portions. The dimension of the teeth of the input rotor 44A in a direction parallel to the intermediate shaft central axis C4 is smaller than the dimension in the radial direction of the intermediate shaft central axis C4. The dimension of the teeth of the output rotor 44B in a direction parallel to the output section rotation central axis C2 is smaller than the dimension in the radial direction of the output section rotation central axis C2.

For example, the reducer 24 includes a first rotating member 50. The first rotating member 50 is provided with an output rotating body 38B and an input rotating body 40A. For example, the first rotating member 50 is configured to rotate integrally with the output rotating body 38B and the input rotating body 40A. For example, the output rotating body 38B and the input rotating body 40A are formed integrally with the first rotating member 50. The first rotating member 50 is disposed on the outer periphery of the intermediate shaft 36. For example, the rotation axis of the first rotating member 50 is coaxial with the intermediate shaft center axis C4 of the intermediate shaft 36. For example, the first rotating member 50 is provided on the outer periphery of the intermediate shaft 36 so as to rotate relative to the intermediate shaft 36. For example, the drive unit 10 includes a pair of fourth bearings 56, and the first rotating member 50 is supported on the intermediate shaft 36 via the pair of fourth bearings 56. For example, the fourth bearings 56 may be ball bearings, roller bearings, or plain bearings.

For example, the reducer 24 includes a second rotating member 52. For example, the second rotating member 52 is provided with an output rotating body 40B and an input rotating body 42A. For example, the second rotating member 52 is configured to rotate integrally with the output rotating body 40B and the input rotating body 42A. For example, the output rotating body 40B and the input rotating body 42A are formed integrally with the second rotating member 52. The second rotating member 52 is disposed on the outer periphery of the input rotating shaft 12. For example, the rotation axis of the second rotating member 52 is coaxial with the input rotation center axis C3 of the input rotating shaft 12. For example, the second rotating member 52 is provided on the outer periphery of the input rotating shaft 12 so as to rotate relative to the input rotating shaft 12. For example, the drive unit 10 includes a pair of fifth bearings, and the second rotating member 52 is supported on the input rotating shaft 12 via the pair of fifth bearings. For example, the fifth bearings may be ball bearings, roller bearings, or plain bearings.

For example, the reducer 24 includes a third rotating member 54. For example, the third rotating member 54 is provided with an output rotating body 42B and an input rotating body 44A. For example, the third rotating member 54 is configured to rotate integrally with the output rotating body 42B and the input rotating body 44A. For example, the output rotating body 42B and the input rotating body 44A are formed integrally with the third rotating member 54. The third rotating member 54 is disposed on the outer periphery of the intermediate shaft 36. For example, the rotation axis of the third rotating member 54 is coaxial with the intermediate shaft central axis C4 of the intermediate shaft 36. For example, the third rotating member 54 is provided on the outer periphery of the intermediate shaft 36 so as to rotate relative to the intermediate shaft 36. For example, the drive unit 10 includes a pair of sixth bearings 58, and the third rotating member 54 is supported on the intermediate shaft 36 via the pair of sixth bearings 58. For example, the sixth bearings 58 may be ball bearings, roller bearings, or plain bearings.

In the drive unit 10 of this embodiment, a first transmission 38, a second transmission 40, a third transmission 42, and a fourth transmission 44 are provided on the motor output shaft 18, the intermediate shaft 36 , the input rotating shaft 12, and the output section 26. The input rotating shaft 12 and the output section 26 are provided coaxially. Therefore, the reducer 24 can perform four-stage reduction in speed using shaft members that rotate substantially about three axes.

For example, at least a portion of the first rotating member 50 is disposed between the first plane A1 and the second plane A2. In this embodiment, the portion of the first rotating member 50 where the input rotating body 40A is formed is disposed between the first plane A1 and the second plane A2. For example, the second rotating member 52 and the third rotating member 54 are disposed between the first plane A1 and the second plane A2.

For example, output rotor 38B is arranged so as to overlap output rotor 40B when viewed in the first direction X1. For example, output rotor 42B is arranged so as to overlap output rotor 44B when viewed in the first direction X1. For example, output rotors 38B, 40B, 42B, and 44B are arranged so as not to overlap motor 16 when viewed in the first direction X1. For example, input rotors 40A, 42A, and 44A are arranged so as not to overlap motor 16 when viewed in the first direction X1.

In the drive unit 10 of this embodiment, at least a portion of the reducer 24 is disposed between the first plane A1 and the second plane A2, allowing the dimensions of the drive unit 10 in the first direction X1 to be reduced. For example, by disposing at least a portion of the reducer 24 between the first plane A1 and the second plane A2, the axial length of the portion of the housing 14 where the input rotation shaft 12 is disposed can be 70 mm or less. For example, by disposing at least a portion of the reducer 24 between the first plane A1 and the second plane A2, the axial length of the portion of the housing 14 where the input rotation shaft 12 is disposed can be 65 mm or less.

In this embodiment, the radii of the input rotors 38A, 40A, 42A, and 44A are all equal. At least one of the radii of the input rotors 38A, 40A, 42A, and 44A may be different from the others. For example, the radii of the input rotors 38A, 40A, 42A, and 44A may be selected arbitrarily depending on the reduction ratio desired for each transmission 38, 40, 42, and 44.

In this embodiment, the radii of the output rotors 38B, 40B, 42B, and 44B are all equal. At least one of the radii of the output rotors 38B, 40B, 42B, and 44B may be different from the others. For example, the radii of the output rotors 38B, 40B, 42B, and 44B may be selected arbitrarily depending on the reduction ratio desired for each transmission 38, 40, 42, and 44.

For example, the endless annular members 38C, 40C, 42C, and 44C are formed by the first chain 46 or the second chain 48.

For example, the first chain 46 includes a first inner link 46A, a second inner link 46B, a first outer link 46C, a second outer link 46D, multiple pins 46E, and a roller 46F. For example, the first inner link 46A is configured to face the second inner link 46B in the second direction X2. For example, the second direction X2 is a direction perpendicular to the chain drive direction Y1. The first inner link 46A includes a first inner link hole 46AX and a second inner link hole 46AY. The second inner link 46B includes a third inner link hole 46BX facing the first inner link hole 46AX and a fourth inner link hole 46BY facing the second inner link hole 46AY.

For example, the first outer link 46C is configured to face the second outer link 46D in the second direction X2. The first outer link 46C includes a first outer link hole 46CX and a second outer link hole 46CY. The second outer link 46D includes a third outer link hole 46DX facing the first outer link hole 46CX and a fourth outer link hole 46DY facing the second outer link hole 46CY.

One of the multiple pins 46E is configured to pass through the second outer link hole 46CY, the first inner link hole 46AX, the third inner link hole 46BX, and the fourth outer link hole 46DY. One of the multiple pins 46E is configured to pass through the first outer link hole 46CX, the second inner link hole 46AY, the fourth inner link hole 46BY, and the third outer link hole 46DX.

The roller 46F is configured to cover at least a portion of the pin 46E in the second direction X2. For example, the roller 46F is configured to cover, in the second direction X2, the portion of the pin 46E that is positioned in the first inner link hole 46AX to the portion that is positioned in the third inner link hole 46BX. For example, the roller 46F is configured to cover, in the second direction X2, the portion of the pin 46E that is positioned in the second inner link hole 46AY to the portion that is positioned in the fourth inner link hole 46BY.

For example, the first chain 46 includes a pair of joint pins 46G and a clip 46H. One of the pair of joint pins 46G is configured to pass through the second outer link hole 46CY, the first inner link hole 46AX, the third inner link hole 46BX, and the fourth outer link hole 46DY. The other of the pair of joint pins 46G is configured to pass through the first outer link hole 46CX, the second inner link hole 46AY, the fourth inner link hole 46BY, and the third outer link hole 46DX.

For example, the clip 46H is configured to be detachably attached to a pair of joint pins 46G so that one of the pair of joint pins 46G passes through the second outer link hole 46CY, the first inner link hole 46AX, the third inner link hole 46BX, and the fourth outer link hole 46DY. For example, the clip 46H is configured to be detachably attached to a pair of joint pins 46G so that the other of the pair of joint pins 46G passes through the first outer link hole 46CX, the second inner link hole 46AY, the fourth inner link hole 46BY, and the third outer link hole 46DX. The roller 46F is configured to cover at least a portion of the joint pin 46G in the second direction X2. For example, the roller 46F is configured to cover, in the second direction X2, the portion of the joint pin 46G that is positioned in the first inner link hole 46AX to the portion that is positioned in the third inner link hole 46BX. For example, roller 46F is configured to cover, in second direction X2, the portion of joint pin 46G that is positioned in second inner link hole 46AY to the portion that is positioned in fourth inner link hole 46BY.

For example, the first chain 46 includes multiple engagement portions 46J. The multiple engagement portions 46J include multiple sliding surfaces formed on the rollers 46F. For example, the first chain 46 is configured to engage with the input sprocket and the output sprocket at the multiple sliding surfaces. The multiple engagement portions 46J correspond to the multiple engagement portions of the endless annular members 38C, 40C, 42C, and 44C. The multiple engagement portions 46J are arranged side by side at a predetermined pitch width P1.

For example, the second chain 48 includes a first inner link 48A, a second inner link 48B, a first outer link 48C, a second outer link 48D, multiple pins 48E, and a roller 48F. For example, the first inner link 48A is configured to face the second inner link 48B in the second direction X2. The first inner link 48A includes a first inner link hole 48AX and a second inner link hole 48AY. The second inner link 48B includes a third inner link hole 48BX facing the first inner link hole 48AX and a fourth inner link hole 48BY facing the second inner link hole 48AY.

For example, the first outer link 48C is configured to face the second outer link 48D in the second direction X2. The first outer link 48C includes a first outer link hole 48CX and a second outer link hole 48CY. The second outer link 48D includes a third outer link hole 48DX facing the first outer link hole 48CX and a fourth outer link hole 48DY facing the second outer link hole 48CY.

One of the multiple pins 48E is configured to pass through the second outer link hole 48CY, the first inner link hole 48AX, the third inner link hole 48BX, and the fourth outer link hole 48DY. One of the multiple pins 48E is configured to pass through the first outer link hole 48CX, the second inner link hole 48AY, the fourth inner link hole 48BY, and the third outer link hole 48DX.

The roller 48F is configured to cover at least a portion of the pin 48E in the second direction X2. For example, the roller 48F is configured to cover, in the second direction X2, from the portion of the pin 48E positioned in the first inner link hole 48AX to the portion positioned in the third inner link hole 48BX. For example, the roller 48F is configured to cover, in the second direction X2, from the portion of the pin 48E positioned in the second inner link hole 48AY to the portion positioned in the fourth inner link hole 48BY.

For example, the second chain 48 includes a pair of joint pins 48G and a clip 48H. One of the pair of joint pins 48G is configured to pass through the second outer link hole 48CY, the first inner link hole 48AX, the third inner link hole 48BX, and the fourth outer link hole 48DY. The other of the pair of joint pins 48G is configured to pass through the first outer link hole 48CX, the second inner link hole 48AY, the fourth inner link hole 48BY, and the third outer link hole 48DX.

For example, the clip 48H is configured to be detachably attached to a pair of joint pins 48G so that one of the pair of joint pins 48G passes through the second outer link hole 48CY, the first inner link hole 48AX, the third inner link hole 48BX, and the fourth outer link hole 48DY. For example, the clip 48H is configured to be detachably attached to a pair of joint pins 48G so that the other of the pair of joint pins 48G passes through the first outer link hole 48CX, the second inner link hole 48AY, the fourth inner link hole 48BY, and the third outer link hole 48DX. The roller 48F is configured to cover at least a portion of the joint pin 48G in the second direction X2. For example, the roller 48F is configured to cover, in the second direction X2, the portion of the joint pin 48G that is positioned in the first inner link hole 48AX to the portion that is positioned in the third inner link hole 48BX. For example, roller 48F is configured to cover, in second direction X2, the portion of joint pin 48G that is positioned in second inner link hole 48AY to the portion that is positioned in fourth inner link hole 48BY.

For example, the second chain 48 includes multiple engagement portions 48J. The multiple engagement portions 48J include multiple sliding surfaces formed on the rollers 48F. For example, the first chain 46 is configured to engage with the input sprocket and the output sprocket at the multiple sliding surfaces. For example, the multiple engagement portions 48J of the second chain 48 correspond to the multiple engagement portions of the endless annular members 38C, 40C, 42C, and 44C. The multiple engagement portions 48J are arranged side by side at a predetermined pitch width P2.

For example, the pitch width P1 of the first chain 46 and the pitch width P2 of the second chain 48 are 4.0 mm or more and 8.0 mm or less. For example, the pitch width P1 is the distance between the axial centers of the multiple pins 46E in a direction perpendicular to the second direction X2. For example, the pitch width P2 is the distance between the axial centers of the multiple pins 48E in a direction perpendicular to the second direction X2. For example, the pitch width P2 is larger than the pitch width P1. For example, the pitch width P1 is 4.7625 mm. For example, the pitch width P2 is 6.35 mm. For example, the pitch widths P1 and P2 correspond to the predetermined pitch widths of the endless annular members 38C, 40C, 42C, and 44C.

For example, the inner link width L1 of the first chain 46 and the inner link width L2 of the second chain 48 are 2.0 mm or more and 3.3 mm or less. For example, the inner link width L1 is the distance from the first inner link 46A to the second inner link 46B. For example, the inner link width L2 is the distance from the first inner link 48A to the second inner link 48B. For example, the inner link width L1 is smaller than the inner link width L2 . For example, the inner link width L1 is 2.38 mm. For example, the inner link width L2 is 3.18 mm. The inner link width L1 is equal to or less than the inner link width L2. For example, the inner link width L1 is in the range of 50% to 80% of the inner link width L2.

For example, the diameter PD1 of the pin 46E of the first chain 46 and the diameter PD2 of the pin 48E of the second chain 48 are 1.5 mm or more and 3.66 mm or less. For example, the diameter PD2 is larger than the diameter PD1. For example, the diameter PD1 is 1.62 mm. For example, the diameter PD2 is 2.31 mm.

For example, the diameter RD1 of the roller 46F of the first chain 46 and the diameter RD2 of the roller 48F of the second chain 48 are 2.0 mm or more and 7.8 mm or less. For example, the diameter RD2 is larger than the diameter RD1. For example, the diameter RD1 is 2.48 mm. For example, the diameter RD2 is 3.3 mm.

For example, the first chain 46 and the second chain 48 may be surface treated by vanadizing or chromizing. For example, one of the first chain 46 and the second chain 48 may be vanadized, and the other of the first chain 46 and the second chain 48 may be chromized.

In the first embodiment, the drive unit 10 may be configured as in any one of the first, second, third, fourth, and fifth configuration examples.

<First Configuration Example>
In the following, a first configuration example of the drive unit 10 will be described.
The drive unit 10 of the first configuration example includes a housing 14, an input section 22, a first transmission section, a second transmission section, and an output section 26. The first transmission section is provided in the housing 14 and receives a driving force via the input section 22. The first transmission section includes a first input rotor, a first output rotor having a different diameter from the first input rotor, and a first endless annular member wound around the first input rotor and the first output rotor. The first endless annular member includes a plurality of first engaging portions that engage with the first input rotor and the first output rotor, respectively, and have a first pitch width in the extension direction of the first endless annular member.

The second transmission unit is provided in the housing 14 and receives the driving force via the first transmission unit. The second transmission unit includes a second input rotor, a second output rotor having a different diameter than the second input rotor, and a second endless annular member that is wrapped around the second input rotor and the second output rotor. The second endless annular member includes a plurality of second engaging portions that engage with the second input rotor and the second output rotor, respectively, and have a second pitch width in the direction in which the second endless annular member extends. The output unit 26 is provided in the housing 14 and is rotatable, and receives the driving force via the second transmission unit.

The first pitch width is different from the second pitch width. For example, the second pitch width is larger than the first pitch width. For example, the first pitch width is 4 mm or more and 10 mm or less. For example, the first pitch width is 4.5 mm or more and 8 mm or less. For example, the second pitch width is 4 mm or more and 10 mm or less and larger than the first pitch width. For example, the second pitch width is 4.5 mm or more and 8 mm or less and larger than the first pitch width. For example, the first endless annular member is the first chain 46, and the second endless annular member is the second chain 48.

For example, the first transmission unit and the second transmission unit each constitute a reducer 24. For example, the first output rotor is configured to rotate integrally with the second input rotor. For example, the first output rotor is formed integrally with the second input rotor. For example, the first input rotor includes a first sprocket, the first output rotor includes a second sprocket, and the first endless annular member includes a chain. The first input rotor includes a plurality of teeth on its outer periphery around the rotation axis. The first output rotor includes a plurality of teeth on its outer periphery around the rotation axis. The second input rotor includes a plurality of teeth on its outer periphery around the rotation axis. The second output rotor includes a plurality of teeth on its outer periphery around the rotation axis.

For example, the drive unit 10 further includes a third transmission unit provided in the housing 14, to which driving force is input via the second transmission unit. For example, the third endless annular member includes a plurality of third engagement portions that engage with the third input rotor and the third output rotor, respectively, and have a third pitch width in the direction in which the third endless annular member extends. For example, the third transmission unit includes a third input rotor, a third output rotor having a different diameter from the third input rotor, and a third endless annular member that is wound around the third input rotor and the third output rotor. For example, driving force is input to the output unit 26 via the third transmission unit. For example, the third input rotor includes a sprocket, the third output rotor includes a sprocket, and the third endless annular member includes a chain. For example, the third transmission unit constitutes a reducer 24. The third input rotor includes a plurality of teeth on its outer periphery around the rotation axis. The third output rotor includes a plurality of teeth on its outer periphery around the rotation axis.

For example, the third pitch width is different from at least one of the first pitch width and the second pitch width. In this configuration example, the third pitch width is different from at least the first pitch width. For example, the third pitch width is larger than at least one of the first pitch width and the second pitch width. In this configuration example, the third pitch width is larger than at least the first pitch width. For example, the third pitch width is 4 mm or more, 10 mm or less, and larger than the first pitch width. For example, the third pitch width is 4.5 mm or more, 8 mm or less, and larger than the first pitch width. For example, the first endless annular member is the first chain 46, the second endless annular member is the second chain 48, and the third endless annular member is the second chain 48. The first endless annular member may be the first chain 46, the second endless annular member may be the first chain 46, and the third endless annular member may be the second chain 48.

For example, the drive unit 10 further includes a fourth transmission unit provided in the housing 14, to which the driving force is input via the third transmission unit. For example, the fourth endless annular member includes a plurality of fourth engagement portions that engage with the fourth input rotor and the fourth output rotor, respectively, and have a fourth pitch width in the direction in which the fourth endless annular member extends. For example, the fourth transmission unit includes a fourth input rotor, a fourth output rotor having a different diameter from the fourth input rotor, and a fourth endless annular member that is wound around the fourth input rotor and the fourth output rotor. For example, the driving force is input to the output unit 26 via the fourth transmission unit. For example, the fourth transmission unit constitutes a reducer 24. For example, the fourth input rotor includes a sprocket, the fourth output rotor includes a sprocket, and the fourth endless annular member includes a chain. For example, the driving force is input to the output unit 26 via the first transmission unit. The fourth input rotor includes a plurality of teeth on its outer periphery around the rotation axis. The fourth output rotor includes multiple teeth on its outer periphery around the rotation axis.

For example, the fourth pitch width is different from at least one of the first pitch width, the second pitch width, and the third pitch width. In this configuration example, the fourth pitch width is different from at least the first pitch width. For example, the fourth pitch width is larger than at least one of the first pitch width, the second pitch width, and the third pitch width. In this configuration example, the fourth pitch width is larger than at least the first pitch width. For example, the fourth pitch width is 4 mm or more and 10 mm or less, and larger than the first pitch width. For example, the fourth pitch width is 4.5 mm or more and 8 mm or less, and larger than the first pitch width.

For example, in this configuration example, the first endless annular member is the first chain 46, the second endless annular member is the second chain 48, the third endless annular member is the second chain 48, and the fourth endless annular member is the second chain 48. The first endless annular member may be the first chain 46, the second endless annular member may be the first chain 46, the third endless annular member may be the second chain 48, and the fourth endless annular member may be the second chain 48. For example, in this configuration example, the first endless annular member may be the first chain 46, the second endless annular member may be the first chain 46, the third endless annular member may be the first chain 46, and the fourth endless annular member may be the second chain 48.

In this configuration example, the first endless annular member, the second endless annular member, the third endless annular member, and the fourth endless annular member are arranged in the driving force transmission path in the following order: first endless annular member, second endless annular member, third endless annular member, and fourth endless annular member. For example, the first endless annular member, the second endless annular member, the third endless annular member, and the fourth endless annular member are configured so that the pitch width increases the closer they are to the output section 26 in the driving force transmission path. For example, the first endless annular member, the second endless annular member, the third endless annular member, and the fourth endless annular member are configured so that the pitch width does not decrease when they are directed toward the input section 22 in the driving force transmission path.

For example, in this configuration example, the first transmission unit corresponds to the first transmission 38, and the second transmission unit corresponds to the second transmission 40. In this configuration example, the first input rotor corresponds to the input rotor 38A, the first output rotor corresponds to the output rotor 38B, and the first endless annular member corresponds to the endless annular member 38C. For example, in this configuration example, the multiple first engagement portions correspond to the multiple engagement portions of the endless annular member 38C. For example, in this configuration example, the second input rotor corresponds to the input rotor 40A, the second output rotor corresponds to the output rotor 40B, and the second endless annular member corresponds to the endless annular member 40C. For example, in this configuration example, the second input rotor includes a sprocket, the second output rotor includes a sprocket, and the second endless annular member includes a chain. For example, in this configuration example, the multiple second engagement portions correspond to the multiple engagement portions of the endless annular member 40C.

For example, in this configuration example, the third transmission unit corresponds to the third transmission 42. For example, in this configuration example, the third input rotor corresponds to the input rotor 42A, the third output rotor corresponds to the output rotor 42B, and the third endless annular member corresponds to the endless annular member 42C.

For example, in this configuration example, the fourth transmission unit corresponds to the fourth transmission 44. For example, in this configuration example, the fourth input rotor corresponds to the input rotor 44A, the fourth output rotor corresponds to the output rotor 44B, and the fourth endless annular member corresponds to the endless annular member 44C.

<Second Configuration Example>
The drive unit 10 of the second configuration example will be described below.
The drive unit 10 of the second configuration example includes a housing 14, a motor 16, a reducer 24, and an output section 26. The reducer 24 includes a first transmission section, a second transmission section, and an intermediate shaft 36.

The first transmission unit includes a first input rotor arranged coaxially with the motor output shaft 18 and receiving driving force from the motor 16, a first output rotor having a different diameter from the first input rotor and attached to the intermediate shaft 36, and a first endless annular member wound around the first input rotor and the first output rotor. For example, the first input rotor includes a first sprocket, the first output rotor includes a second sprocket, and the first endless annular member includes a chain.

The second transmission unit includes a second input rotor provided on the intermediate shaft 36, to which driving force is input via the first output rotor; a second output rotor having a different diameter from the second input rotor and arranged coaxially with the output unit 26; and a second endless annular member wound around the second input rotor and the second output rotor. For example, the second input rotor includes a first sprocket, the second output rotor includes a second sprocket, and the second endless annular member includes a chain.

For example, the first output rotor is configured to rotate integrally with the second input rotor. For example, the first output rotor is formed integrally with the second input rotor.

For example, the reducer 24 further includes a third transmission unit provided in the housing 14 and receiving driving force via the second transmission unit. For example, the third transmission unit includes a third input rotor, a third output rotor having a different diameter than the third input rotor, and a third endless annular member wound around the third input rotor and the third output rotor. For example, the third input rotor includes a first sprocket, the third output rotor includes a second sprocket, and the third endless annular member includes a chain. For example, the third input rotor is arranged coaxially with the output unit 26. For example, the third output rotor is arranged coaxially with the intermediate shaft 36.

For example, the reducer 24 further includes a fourth transmission unit provided in the housing 14 and receiving driving force via the third transmission unit. For example, the fourth transmission unit includes a fourth input rotor, a fourth output rotor having a different diameter than the fourth input rotor, and a fourth endless annular member wound around the fourth input rotor and the fourth output rotor. For example, the fourth input rotor includes a first sprocket, the fourth output rotor includes a second sprocket, and the fourth endless annular member includes a chain. For example, the fourth input rotor is arranged coaxially with the intermediate shaft 36. For example, the fourth output rotor is arranged coaxially with the output unit 26.

For example, the output unit 26 is provided in the housing 14 and configured to be rotatable, and a driving force is input to it via the first and second transmission units. For example, a driving force is input to the output unit 26 via the third transmission unit. For example, a driving force is input to the output unit 26 via the fourth transmission unit.

The motor rotational center axis C1 of the motor output shaft 18, the intermediate shaft center axis C4 of the intermediate shaft 36, and the output section rotational center axis C2 of the output section 26 extend substantially parallel to the first direction X1. For example, the motor rotational center axis C1, the intermediate shaft center axis C4, and the output section rotational center axis C2 are arranged so that they are located at the vertices of a triangle when viewed in the first direction X1.

For example, the triangular shape can be configured arbitrarily. In this configuration example, the length from the motor rotation central axis C1 to the intermediate shaft central axis C4 is greater than the sum of the radius of the first end face B1 of the rotation mechanism 16X and the radius of the first output rotor. In this configuration example, the length from the motor rotation central axis C1 to the intermediate shaft central axis C4 is greater than the sum of the radius of the first end face B1 of the rotation mechanism 16X and the radius of the third output rotor. In this configuration example, the length from the intermediate shaft central axis C4 to the output section rotation central axis C2 is less than the sum of the radius of the first output rotor and the radius of the second output rotor. In this configuration example, the length from the intermediate shaft central axis C4 to the output section rotation central axis C2 is less than the sum of the radius of the third output rotor and the radius of the fourth output rotor. In this configuration example, the length from the output section rotation central axis C2 to the motor rotation central axis C1 is greater than the sum of the radius of the first output rotor and the radius of the first end face B1 of the rotation mechanism 16X. In this configuration example, the length from the output rotation central axis C2 to the motor rotation central axis C1 is greater than the sum of the radius of the fourth output rotor and the radius of the second end face B2 of the rotation mechanism 16X.

For example, in this configuration example, the first transmission unit corresponds to the first transmission 38, and the second transmission unit corresponds to the second transmission 40. For example, in this configuration example, the first input rotor corresponds to the input rotor 38A, the first output rotor corresponds to the output rotor 38B, and the first endless annular member corresponds to the endless annular member 38C. For example, in this configuration example, the second input rotor corresponds to the input rotor 40A, the second output rotor corresponds to the output rotor 40B, and the second endless annular member corresponds to the endless annular member 40C. For example, in this configuration example, the third transmission unit corresponds to the third transmission 42. For example, in this configuration example, the third input rotor corresponds to the input rotor 42A, the third output rotor corresponds to the output rotor 42B, and the third endless annular member corresponds to the endless annular member 42C. For example, in this configuration example, the fourth transmission unit corresponds to the fourth transmission 44. For example, in this configuration example, the fourth input rotor corresponds to input rotor 44A, the fourth output rotor corresponds to output rotor 44B, and the fourth endless annular member corresponds to endless annular member 44C. For example, in this configuration example, the motor rotational center axis C1 of the motor output shaft 18, the intermediate shaft center axis C4 of the intermediate shaft 36, and the output portion rotational center axis C2 of the output portion 26 extend parallel to the first direction X1.

<Third Configuration Example>
The drive unit 10 of the third configuration example will be described below.
The drive unit 10 of the third configuration example includes a housing 14, a motor 16, a reducer 24, and an output section 26. The reducer 24 includes a first transmission section and a second transmission section. The first transmission section includes a first input rotor to which driving force is input from the motor 16, a first output rotor having a different diameter than the first input rotor, a first endless annular member wound around the first input rotor and the first output rotor, and an intermediate shaft 36 that is offset from the motor output shaft 18 and the output section 26 and is substantially parallel to the motor output shaft 18. For example, the first input rotor includes a first sprocket, the first output rotor includes a second sprocket, and the first endless annular member includes a chain.

The second transmission section includes a second input rotor to which driving force is input via the first output rotor, a second output rotor having a different diameter from the second input rotor and arranged coaxially with the output section 26, and a second endless annular member wrapped around the second input rotor and the second output rotor.

One of the first input rotor and the first output rotor, and one of the second input rotor and the second output rotor are mounted on the motor output shaft 18 or the intermediate shaft 36 so as to be rotatable relative to each other. In this configuration example, the first output rotor and the second input rotor are configured to be rotatable relative to the intermediate shaft 36. In this configuration example, the first input rotor is mounted on the motor output shaft 18 and configured to be rotatable relative to the motor output shaft 18. For example, one of the first input rotor and the first output rotor, and one of the second input rotor and the second output rotor are mounted on the intermediate shaft 36. For example, at least one of the first input rotor and the first output rotor, and one of the second input rotor and the second output rotor are configured to be rotatable relative to the intermediate shaft 36. In this configuration example, the first output rotor and the second input rotor are mounted on the intermediate shaft 36. In this configuration example, the second output rotor is provided on the input rotation shaft 12 and is configured to be rotatable relative to the input rotation shaft 12.

For example, the reducer 24 further includes a third transmission unit provided in the housing 14. For example, the third transmission unit includes a third input rotor, a third output rotor having a different diameter from the third input rotor, and a third endless annular member wound around the third input rotor and the third output rotor.

For example, one of the third input rotor and the third output rotor is provided on the intermediate shaft 36 and is configured to be rotatable relative to the second input rotor. In this configuration example, the third output rotor is provided on the intermediate shaft 36 and is configured to be rotatable relative to the second input rotor.

For example, the reducer 24 further includes a fourth transmission unit provided in the housing 14. For example, the fourth transmission unit includes a fourth input rotor, a fourth output rotor having a different diameter than the fourth input rotor, and a fourth endless annular member wound around the fourth input rotor and the fourth output rotor. For example, the fourth input rotor includes a first sprocket, the fourth output rotor includes a second sprocket, and the fourth endless annular member includes a chain. In this configuration example, the third output rotor is provided on the intermediate shaft 36. In this configuration example, the fourth input rotor is formed integrally with the third output rotor.

For example, in this configuration example, the first transmission unit corresponds to the first transmission 38, and the second transmission unit corresponds to the second transmission 40. For example, in this configuration example, the first input rotor corresponds to the input rotor 38A, the first output rotor corresponds to the output rotor 38B, and the first endless annular member corresponds to the endless annular member 38C. For example, in this configuration example, the second input rotor corresponds to the input rotor 40A, the second output rotor corresponds to the output rotor 40B, and the second endless annular member corresponds to the endless annular member 40C.

For example, the third transmission unit in this configuration example corresponds to the third transmission 42. For example, the third input rotor in this configuration example corresponds to the input rotor 42A, the third output rotor corresponds to the output rotor 42B, and the third endless annular member corresponds to the endless annular member 42C. For example, the fourth transmission unit in this configuration example corresponds to the fourth transmission 44. For example, the fourth input rotor in this configuration example corresponds to the input rotor 44A, the fourth output rotor corresponds to the output rotor 44B, and the fourth endless annular member corresponds to the endless annular member 44C.

In this configuration example, the transmissions corresponding to the first, second, third, and fourth transmissions may be selected arbitrarily from among the first transmission 38, second transmission 40, third transmission 42, and fourth transmission 44. For example, the combination of the first, second, third, and fourth transmissions can be any of selection examples E11 to E18 in Table 1.

In selection example E11 and selection example E12, the first input rotor and the second input rotor are provided on the intermediate shaft 36 so as to be rotatable relative to the intermediate shaft 36. In selection example E11, the third output rotor and the fourth output rotor are provided on the intermediate shaft 36 so as to be rotatable relative to the intermediate shaft 36. In selection example E12, the third output rotor and the fourth output rotor are provided on the intermediate shaft 36 so as to be rotatable relative to the intermediate shaft 36.

In selection examples E13 and E14, the first input rotor and the second output rotor are provided on the intermediate shaft 36 so as to be rotatable relative to the intermediate shaft 36. In selection example E13, the third input rotor and the fourth output rotor are provided on the intermediate shaft 36 so as to be rotatable relative to the intermediate shaft 36. In selection example E14, the third output rotor and the fourth input rotor are provided on the intermediate shaft 36 so as to be rotatable relative to the intermediate shaft 36.

In Selection Example E15 and Selection Example E16, the first output rotor and the second input rotor are provided on the intermediate shaft 36 so as to be rotatable relative to the intermediate shaft 36. In Selection Example E15 , the third output rotor and the fourth input rotor are provided on the intermediate shaft 36 so as to be rotatable relative to the intermediate shaft 36. In Selection Example E16, the third input rotor and the fourth output rotor are provided on the intermediate shaft 36 so as to be rotatable relative to the intermediate shaft 36.

In selection example E17 and selection example E18, the first output rotor and the second output rotor are provided on the intermediate shaft 36 so as to be rotatable relative to the intermediate shaft 36. In selection example E17, the third input rotor and the fourth input rotor are provided on the intermediate shaft 36 so as to be rotatable relative to the intermediate shaft 36. In selection example E18, the third input rotor and the fourth input rotor are provided on the intermediate shaft 36 so as to be rotatable relative to the intermediate shaft 36.

<Fourth Configuration Example>
The drive unit 10 of the fourth configuration example will be described below.
The drive unit 10 of this configuration example includes a housing 14, a motor 16, a first transmission unit, and an output unit 26. For example, a driving force is input to the output unit 26 via a second transmission unit.

For example, the first transmission unit constitutes a reducer 24. The first transmission unit is provided in the housing 14 and receives driving force from the motor 16. The first transmission unit includes a first input rotor, a first output rotor having a different diameter than the first input rotor, and a first endless annular member wound around the first input rotor and the first output rotor. For example, the first input rotor includes a first sprocket, the first output rotor includes a second sprocket, and the first endless annular member includes a chain.

At least a portion of the first transmission unit is disposed between the first plane A1 and the second plane A2. For example, at least a portion of the first endless annular member of the first transmission unit is disposed between the first plane A1 and the second plane A2. In this configuration example, the entire first endless annular member is disposed between the first plane A1 and the second plane A2. For example, the first endless annular member is configured to be driven between the first plane A1 and the second plane A2 in a direction parallel to the first plane A1 and the second plane A2.

For example, the first input rotation center axis of the first input rotor and the first output rotation center axis of the first output rotor are arranged substantially parallel to the first direction X1. In this configuration example, the first input rotation center axis of the first input rotor and the first output rotation center axis of the first output rotor are arranged parallel to the first direction X1. For example, the first input rotor and the first output rotor are arranged between the first plane A1 and the second plane A2 so as to be aligned in a direction perpendicular to the first direction X1.

For example, the drive unit 10 further includes a second transmission section provided in the housing 14, to which driving force is input via the first transmission section. For example, the second transmission section constitutes a reducer 24. The second transmission section includes a second input rotor, a second output rotor having a different diameter from the second input rotor, and a second endless annular member wound around the second input rotor and the second output rotor. For example, the second input rotor includes a first sprocket, the second output rotor includes a second sprocket, and the third endless annular member includes a chain.

For example, at least a portion of the second transmission unit is disposed between the first plane A1 and the second plane A2. For example, at least a portion of the second endless annular member of the second transmission unit is disposed between the first plane A1 and the second plane A2. In this configuration example, the entire second endless annular member is disposed between the first plane A1 and the second plane A2. For example, the second endless annular member is configured to be driven between the first plane A1 and the second plane A2 in a direction parallel to the first plane A1 and the second plane A2.

For example, the second input rotation center axis of the second input rotor and the second output rotation center axis of the second output rotor are arranged substantially parallel to the first direction X1. In this configuration example, the second input rotation center axis of the second input rotor and the second output rotation center axis of the second output rotor are arranged parallel to the first direction X1. For example, the second input rotor and the second output rotor are arranged between the first plane A1 and the second plane A2 so as to be aligned in a direction perpendicular to the first direction X1.

For example, the first output rotor is arranged coaxially with the second input rotor, and the diameter of the first output rotor is different from the diameter of the second input rotor. In this configuration example, the diameter of the first output rotor is larger than the diameter of the second input rotor. For example, the first output rotor is configured to rotate integrally with the second input rotor. For example, the first output rotor is formed integrally with the second input rotor.

For example, the drive unit 10 further includes a third transmission section provided in the housing 14. For example, driving force is input to the first transmission section via the third transmission section. For example, the third transmission section constitutes a reducer 24. For example, the third transmission section includes a third input rotor, a third output rotor having a different diameter from the third input rotor, and a third endless annular member wound around the third input rotor and the third output rotor. For example, the third input rotor includes a first sprocket, the third output rotor includes a second sprocket, and the third endless annular member includes a chain.

For example, the third input rotation center axis of the third input rotor and the third output rotation center axis of the third output rotor are arranged substantially parallel to the first direction X1. In this configuration example, the third input rotation center axis of the third input rotor and the third output rotation center axis of the third output rotor are arranged parallel to the first direction X1. For example, the third input rotor and the third output rotor are arranged so that they are aligned in a direction perpendicular to the first direction X1. For example, the third input rotor and the third output rotor are arranged closer to the first plane A1 than the second plane A2, and farther from the second plane A2 than the first plane A1.

For example, the third output rotor is arranged coaxially with the first input rotor, and the diameter of the third output rotor is different from the diameter of the first input rotor. In this configuration example, the diameter of the third output rotor is larger than the diameter of the first input rotor. For example, the third output rotor is configured to rotate integrally with the first input rotor. For example, the third output rotor is formed integrally with the first input rotor.

For example, at least a portion of the third transmission unit is arranged to overlap at least one of the rotor 16A and the stator 16B when viewed in the first direction X1. In this configuration example, the third input rotating body is arranged to overlap the rotor 16A and the stator 16B when viewed in the first direction X1. In this configuration example, the third endless annular member is arranged to overlap the rotor 16A and the stator 16B when viewed in the first direction X1.

For example, at least a portion of the third transmission unit is arranged to overlap at least a portion of the first transmission unit when viewed in the first direction X1. In this configuration example, the third output rotor is arranged to overlap the first input rotor when viewed in the first direction X1.

For example, the drive unit 10 further includes a fourth transmission unit provided in the housing 14. For example, driving force is input to the fourth transmission unit via the first transmission unit. For example, the fourth transmission unit constitutes a reducer 24. For example, the fourth transmission unit includes a fourth input rotor, a fourth output rotor having a different diameter from the fourth input rotor, and a fourth endless annular member wound around the fourth input rotor and the fourth output rotor. For example, the fourth input rotor includes a first sprocket, the fourth output rotor includes a second sprocket, and the fourth endless annular member includes a chain.

For example, at least a portion of the fourth transmission unit is disposed between the first plane A1 and the second plane A2. For example, at least a portion of the fourth endless annular member of the fourth transmission unit is disposed between the first plane A1 and the second plane A2. In this configuration example, the entire fourth endless annular member is disposed between the first plane A1 and the second plane A2. For example, the fourth endless annular member is configured to be driven between the first plane A1 and the second plane A2 in a direction parallel to the first plane A1 and the second plane A2.

For example, the fourth input rotation center axis of the fourth input rotor and the fourth output rotation center axis of the fourth output rotor are arranged substantially parallel to the first direction X1. In this configuration example, the fourth input rotation center axis of the fourth input rotor and the fourth output rotation center axis of the fourth output rotor are arranged parallel to the first direction X1. For example, the fourth input rotor and the fourth output rotor are arranged between the first plane A1 and the second plane A2 so as to be aligned in a direction perpendicular to the first direction X1.

For example, the first output rotor is arranged coaxially with the fourth output rotor, and the first input rotor is arranged coaxially with the fourth input rotor. For example, the second input rotor is arranged coaxially with the fourth output rotor, and the second output rotor is arranged coaxially with the fourth input rotor. For example, the third output rotor is arranged coaxially with the fourth input rotor.

For example, the first transmission unit in this configuration example corresponds to the second transmission 40. For example, the first input rotor in this configuration example corresponds to the input rotor 40A, the first output rotor corresponds to the output rotor 40B, and the first endless annular member corresponds to the endless annular member 40C. For example, the second transmission unit in this configuration example corresponds to the third transmission 42. For example, the second input rotor in this configuration example corresponds to the input rotor 42A, the second output rotor corresponds to the output rotor 42B, and the second endless annular member corresponds to the endless annular member 42C. For example, the third transmission unit in this configuration example corresponds to the first transmission 38. For example, the third input rotor in this configuration example corresponds to the input rotor 38A, the third output rotor corresponds to the output rotor 38B, and the third endless annular member corresponds to the endless annular member 38C. For example, the fourth transmission unit in this configuration example corresponds to the fourth transmission 44. For example, in this configuration example, the fourth input rotor corresponds to input rotor 44A, the fourth output rotor corresponds to output rotor 44B, and the fourth endless annular member corresponds to endless annular member 44C.

<Fifth Configuration Example>
The drive unit 10 of the fifth configuration example will be described below.
The drive unit 10 includes a housing 14, an input portion 22, a first transmission portion, and an output portion 26. For example, a driving force is input to the output portion 26 via a second transmission portion.

For example, the first transmission unit constitutes a reducer 24. The first transmission unit is provided in the housing 14, and receives driving force via the input unit 22. The first transmission unit includes a first input rotor, a first output rotor having a different diameter than the first input rotor, and a first endless annular member wound around the first input rotor and the first output rotor. For example, the first input rotor includes a first sprocket, the first output rotor includes a second sprocket, and the first endless annular member includes a chain. The first endless annular member includes a plurality of first engaging portions that engage with the first input rotor and the first output rotor, respectively, and have a first pitch width in the direction in which the first endless annular member extends.

The first pitch width is 4 mm or more and 10 mm or less. For example, the first pitch width is 5 mm or more and 8 mm or less. For example, the first endless annular member includes the first chain 46.

For example, the drive unit 10 further includes a second transmission section provided in the housing 14, to which driving force is input via the first transmission section. For example, the second transmission section constitutes a reducer 24. The second transmission section includes a second input rotor, a second output rotor having a different diameter than the second input rotor, and a second endless annular member wound around the second input rotor and the second output rotor. For example, the second input rotor includes a first sprocket, the second output rotor includes a second sprocket, and the second endless annular member includes a chain. The second endless annular member includes a plurality of second engagement portions that engage with the second input rotor and the second output rotor, respectively, and have a second pitch width in the extension direction of the second endless annular member.

For example, the second pitch width is 4 mm or more and 10 mm or less. For example, the second pitch width is 5 mm or more and 8 mm or less. For example, the second endless annular member includes the first chain 46 or the second chain 48.

For example, the drive unit 10 further includes a third transmission section provided in the housing 14 and receiving driving force via the second transmission section. For example, the third transmission section constitutes the reducer 24. In this configuration example, the third transmission section corresponds to the third transmission 42. For example, the third transmission section includes a third input rotor, a third output rotor having a different diameter from the third input rotor, and a third endless annular member wound around the third input rotor and the third output rotor. In this configuration example, the third input rotor corresponds to the input rotor 42A, the third output rotor corresponds to the output rotor 42B, and the third endless annular member corresponds to the endless annular member 42C. For example, the third input rotor includes a first sprocket, the third output rotor includes a second sprocket, and the third endless annular member includes a chain. For example, the third endless annular member includes a plurality of third engagement portions that engage with the third input rotor and the third output rotor, respectively, and have a third pitch width in the direction in which the third endless annular member extends.

For example, the third pitch width is 4 mm or more and 10 mm or less. For example, the third pitch width is 5 mm or more and 8 mm or less. For example, the third endless annular member includes the first chain 46 or the second chain 48. If the second endless annular member is the second chain 48, the third endless annular member includes the second chain 48.

For example, the drive unit 10 further includes a fourth transmission section provided in the housing 14, to which driving force is input via the third transmission section. In this configuration example, the fourth transmission section corresponds to the fourth transmission 44. For example, the fourth transmission section constitutes the reducer 24. For example, the fourth transmission section includes a fourth input rotor, a fourth output rotor having a different diameter from the fourth input rotor, and a fourth endless annular member wound around the fourth input rotor and the fourth output rotor.

In this configuration example, the fourth input rotor corresponds to input rotor 44A, the fourth output rotor corresponds to output rotor 44B, and the fourth endless annular member corresponds to endless annular member 44C. For example, the fourth input rotor includes a first sprocket, the fourth output rotor includes a second sprocket, and the fourth endless annular member includes a chain. For example, the fourth endless annular member includes a plurality of fourth engagement portions that engage with the fourth input rotor and the fourth output rotor, respectively, and have a fourth pitch width in the extension direction of the fourth endless annular member.

For example, the fourth pitch width is 4 mm or more and 10 mm or less. For example, the fourth pitch width is 5 mm or more and 8 mm or less. For example, the fourth endless annular member includes the second chain 48. If the third endless annular member is the second chain 48, the fourth endless annular member includes the second chain 48.

For example, the first input rotation center axis of the first input rotor, the first output rotation center axis of the first output rotor, the second input rotation center axis of the second input rotor, and the second output rotation center axis of the second output rotor are arranged substantially parallel to the first direction X1. In this configuration example, the first input rotation center axis of the first input rotor, the first output rotation center axis of the first output rotor, the second input rotation center axis of the second input rotor, and the second output rotation center axis of the second output rotor are arranged parallel to the first direction X1. For example, the first output rotation center axis of the first output rotor is arranged coaxially with the second input rotation center axis of the second input rotor.

For example, the first output rotor is offset relative to the second input rotor in the first direction X1 and is arranged coaxially with the second input rotor. For example, the first output rotor is offset farther from the second input rotor in the first direction X1 than the first plane A1. For example, the first output rotor is configured to rotate integrally with the second input rotor. For example, the first output rotor is formed integrally with the second input rotor. For example, the first output rotor, together with the second input rotor, constitutes the first rotating member 50.

For example, in the first direction X1, the second transmission unit is arranged between the first transmission unit and the output unit 26. For example, in the first direction X1, the second transmission unit is arranged between the first transmission unit and the third transmission unit. For example, in the drive unit 10, the first transmission unit, second transmission unit, third transmission unit, fourth transmission unit, and output unit 26 are arranged in this order in the first direction X1.

For example, the first transmission unit in this configuration example corresponds to the first transmission 38. For example, the first input rotor in this configuration example corresponds to the input rotor 38A, the first output rotor corresponds to the output rotor 38B, and the first endless annular member corresponds to the endless annular member 38C. For example, the multiple first engagement portions in this configuration example correspond to the multiple engagement portions 46J. For example, the second transmission unit in this configuration example corresponds to the second transmission 40. In this configuration example, the second input rotor corresponds to the input rotor 40A, the second output rotor corresponds to the output rotor 40B, and the second endless annular member corresponds to the endless annular member 40C. For example, the multiple second engagement portions in this configuration example correspond to the multiple engagement portions 48J.

Second Embodiment
The drive unit 10 of the second embodiment will be described with reference to Figures 14 and 15. The drive unit 10 of the second embodiment is similar to the drive unit 10 of the first embodiment except for the configuration of the reducer 24, so the same reference numerals as in the first embodiment are used for the configurations common to the first embodiment, and redundant description will be omitted.

The reducer 24 of the drive unit 10 of this embodiment includes a belt-type reducer. For example, at least one of the first transmission 38, second transmission 40, third transmission 42, and fourth transmission 44 includes a belt-type reducer. The reducer 24 of this embodiment is configured similarly to the first embodiment, except that at least one of the first transmission 38, second transmission 40, third transmission 42, and fourth transmission 44 includes a belt-type reducer.

For example, at least one of the input rotors 38A, 40A, 42A, 44A includes an input pulley, at least one of the output rotors 38B, 40B, 42B, 44B includes an output pulley, and at least one of the endless annular members 38C, 40C, 42C, 44C includes a first belt 60 or a second belt 62. For example, if the first transmission 38 includes a belt-type reducer, the input rotor 38A includes an input pulley, the output rotor 38B includes an output pulley, and the endless annular member 38C includes the first belt 60 or the second belt 62. For example, if the second transmission 40 includes a belt-type reducer, the input rotor 40A includes an input pulley, the output rotor 40B includes an output pulley, and the endless annular member 40C includes the first belt 60 or the second belt 62. For example, if the third transmission 42 includes a belt-type reducer, the input rotor 42A includes an input pulley, the output rotor 42B includes an output pulley, and the endless annular member 42C includes the first belt 60 or the second belt 62. For example, if the fourth transmission 44 includes a belt-type reducer, the input rotor 44A includes an input pulley, the output rotor 44B includes an output pulley, and the endless annular member 44C includes the first belt 60 or the second belt 62.

For example, the first belt 60 is a flat belt including multiple protrusions and a connecting band. For example, the multiple protrusions are provided on the connecting band so that they are adjacent to each other in the second drive direction. For example, the pitch width of the belt in this embodiment is the distance from the center of a protrusion in the second drive direction to the center of an adjacent protrusion in the second drive direction.

For example, the pitch width PV2 of the second belt 62 is larger than the pitch width PV1 of the first belt 60. For example, the pitch width PV1 and the pitch width PV2 are 4 mm or more and 10 mm or less. For example, the pitch width PV1 and the pitch width PV2 are 4.5 mm or more and 8 mm or less. For example, the pitch width PV1 is 4.7625 mm. For example, the pitch width PV2 is 6.35 mm.

In the first, second, third, and fifth configuration examples of the first embodiment, for example, the first input rotor of the drive unit 10 of the second embodiment may include a first pulley, the first output rotor may include a second pulley, and the first endless annular member may be modified to include a belt. In the first, second, third, and fifth configuration examples of the first embodiment, if the first endless annular member is modified to include a belt, the belt includes the first belt 60 or the second belt 62.

In the drive unit 10 of the second embodiment, in the fourth configuration example of the first embodiment, for example, the first input rotor may include a first pulley, the first output rotor may include a second pulley, and the first endless annular member may include a belt. In the fourth configuration example of the first embodiment, if the first endless annular member is modified to include a belt, the belt may include a first belt 60 or a second belt 62.

Third Embodiment
The drive unit 10 of the third embodiment will be described with reference to Fig. 16. The drive unit 10 of the third embodiment is similar to the drive unit 10 of the first embodiment except for the configuration of the reducer 24. Therefore, the same reference numerals as in the first embodiment are used for the configurations common to the first embodiment, and redundant description will be omitted.

In this embodiment, the drive unit 10 further includes a planetary gear reducer 64 arranged in the driving force transmission path between the input section 22 and the output section 26.

For example, at least one of the first transmission 38, second transmission 40, third transmission 42, and fourth transmission 44 includes a planetary gear reducer 64. The reducer 24 of this embodiment is configured similarly to the first embodiment, except that at least one of the first transmission 38, second transmission 40, third transmission 42, and fourth transmission 44 includes a planetary gear reducer 64.

For example, the first transmission 38 includes a planetary gear reducer 64, and at least one of the second transmission 40, the third transmission 42, and the fourth transmission 44 includes a chain reducer. For example, the planetary gear reducer 64 includes a sun gear, a ring gear, multiple planetary gears, and a carrier. The sun gear is provided on the outer periphery of the motor output shaft 18 of the motor 16. The sun gear may be formed integrally with the motor output shaft 18, or may be formed separately from the motor output shaft 18 and attached to it. The multiple planetary gears are disposed between the sun gear and the ring gear. The carrier supports the multiple planetary gears and causes the multiple planetary gears to revolve integrally around the sun gear. In this embodiment, driving force is input to the second transmission 40 via the first transmission 38. For example, the input rotor 40A of the second transmission 40 is configured to rotate integrally with the carrier of the first transmission 38.

The drive unit 10 may further include a gear reducer disposed in the drive force transmission path between the input section 22 and the output section 26. At least one of the first transmission 38, second transmission 40, third transmission 42, and fourth transmission 44 may include a planetary gear reducer 64, and at least one other of the first transmission 38, second transmission 40, third transmission 42, and fourth transmission 44 may include a gear reducer.

For example, the first transmission 38 includes a planetary gear reducer 64, the second transmission 40 includes a gear reducer, and at least one of the third transmission 42 and the fourth transmission 44 includes a chain reducer. For example, the gear reducer includes an input gear and an output gear. For example, the gear reducer is configured so that the rotational speed of the output gear is lower than the rotational speed of the input gear. The input gear is a rotating body that is arranged coaxially with the intermediate shaft 36 and receives driving force via the carrier of the first transmission 38. The output gear is a rotating body that has a different diameter from the input gear and is arranged coaxially with the output section 26. For example, the output gear has a larger diameter than the input gear. For example, the output gear is arranged on the outer circumferential surface of the input rotating shaft 12 and is configured to be rotatable relative to the input rotating shaft 12. For example, the output gear is configured to rotate together with the input gear by meshing the teeth of the output gear with the teeth of the input gear. For example, the gear reducer does not include the planetary gear reducer 64.

In this configuration example, the first transmission 38, second transmission 40, third transmission 42, and fourth transmission 44 are each selected to include either a predetermined reducer, a planetary gear reducer 64, or a gear reducer. For example, the combination of the first transmission 38, second transmission 40, third transmission 42, and fourth transmission 44 can be selected as shown in selection examples E21 to E30 in Table 2.

<Example of change>
The descriptions of each embodiment are intended to exemplify possible forms of the drive unit 10 for a human-powered vehicle according to the present disclosure, and are not intended to limit the forms. The drive unit 10 for a human-powered vehicle according to the present disclosure can take the form of, for example, modified examples of the embodiments shown below, or a combination of at least two mutually consistent modified examples. In the following modified examples, parts that are common to the embodiments are given the same reference numerals as in the embodiments, and their description will be omitted.

- The motor rotational center axis C1, the intermediate shaft center axis C4, and the output unit rotational center axis C2 may be arranged on a straight line when viewed in the first direction X1. For example, as shown in Figures 17 and 18, the motor rotational center axis C1, the intermediate shaft center axis C4, and the output unit rotational center axis C2 are arranged on a first straight line. For example, the intermediate shaft center axis C4 is arranged between the motor rotational center axis C1 and the output unit rotational center axis C2. For example, the intermediate shaft center axis C4 is arranged at a position closer to the output unit rotational center axis C2 than the motor rotational center axis C1.

- The output rotor 40B may be arranged coaxially with the motor output shaft 18. For example, as shown in FIG. 19, the output rotor 40B is arranged on the outer peripheral surface of the motor output shaft 18 and is configured to be rotatable relative to the motor output shaft 18. For example, the input rotor 42A is a rotor arranged coaxially with the motor output shaft 18. For example, the input rotor 42A is arranged on the outer peripheral surface of the motor output shaft 18 and is configured to be rotatable relative to the motor output shaft 18. For example, the second rotating member 52 is arranged on the outer peripheral surface of the motor output shaft 18. When the output rotor 40B is arranged coaxially with the motor output shaft 18, the combination of transmissions corresponding to the first, second, third, and fourth transmission units can be selected from the selection examples in Table 3. In selection examples E41 and E42, the first input rotor and the second input rotor are arranged to be rotatable relative to the motor output shaft 18. In selection examples E43 and E44, the first input rotor and the second output rotor are provided to be rotatable relative to the motor output shaft 18. In selection examples E45 and E46, the first output rotor and the second input rotor are provided to be rotatable relative to the motor output shaft 18.

The first output rotor and the second input rotor may be provided on the intermediate shaft 36 and configured to be non-rotatable relative to the intermediate shaft 36. For example, the first output rotor and the second input rotor may be configured to be rotatable relative to the third output rotor and the fourth input rotor. For example, the intermediate shaft 36 may be configured to be rotatable relative to the housing 14. For example, as shown in FIG. 20 , the drive unit 10 includes a pair of seventh bearings 66, and the intermediate shaft 36 is supported on the housing 14 via the pair of seventh bearings 66. For example, the seventh bearings 66 may be ball bearings, roller bearings, or plain bearings. The output rotor 42B and the input rotor 44A shown in FIG. 20 are configured integrally with the intermediate shaft 36, and the output rotor 38B and the input rotor 40A are configured to be rotatable relative to the intermediate shaft 36. The third rotating member 54 shown in FIG. 20 is configured integrally with the intermediate shaft 36, and the first rotating member 50 is configured separately from the intermediate shaft 36. The output rotor 38B and the input rotor 40A may be configured integrally with the intermediate shaft 36, and the output rotor 42B and the input rotor 44A may be configured to be rotatable relative to the intermediate shaft 36.

- When the endless annular members 38C, 40C, 42C, and 44C include a chain, the chain may include a silent chain.

- In the first embodiment, at least one of the first transmission 38, second transmission 40, third transmission 42, and fourth transmission 44 may be provided outside the housing 14.

- In the first embodiment, at least one of the first transmission 38, second transmission 40, third transmission 42, and fourth transmission 44 may be arranged in the transmission path of the human-powered driving force between the input rotary shaft 12 and the output unit 26. When at least one of the first transmission 38, second transmission 40, third transmission 42, and fourth transmission 44 is arranged in the transmission path of the human-powered driving force, the human-powered driving force may be configured to be input to the first transmission 38. The human-powered driving force may be input to the output unit 26 via at least one of the first transmission 38, second transmission 40, third transmission 42, and fourth transmission 44.

- The drive unit 10 may include a speed-increasing gear. If the drive unit 10 includes a speed-increasing gear, at least one of the first transmission section, second transmission section, third transmission section, and fourth transmission section may constitute a speed-increasing gear. For example, at least one of the first transmission section, second transmission section, third transmission section, and fourth transmission section may constitute a speed-increasing gear, and the remaining first transmission section, second transmission section, third transmission section, and fourth transmission section may constitute a reducer 24.

The drive unit 10 may include one or more transmissions in addition to the first transmission 38, the second transmission 40, the third transmission 42, and the fourth transmission 44. When the drive unit 10 includes one or more transmissions in addition to the first transmission 38, the second transmission 40, the third transmission 42, and the fourth transmission 44, the driving force input to the input section 22 is output from the output section 26 via the first transmission 38, the second transmission 40, the third transmission 42, the fourth transmission 44, and one or more transmissions. For example, in the configuration shown in FIG. 19 , the drive unit 10 may include a fifth transmission and a sixth transmission. For example, the fifth transmission is disposed in the internal space SA of the housing 14 and is provided in the housing 14. For example, the fifth transmission includes an input rotating body, an output rotating body, and an endless annular member.
For example, the fifth transmission changes the rotational speed of the input rotor of the fifth transmission to rotate the output rotor of the fifth transmission. The input rotor of the fifth transmission is arranged coaxially with the intermediate shaft 36 and is a rotor to which driving force is input from the output rotor 42B of the third transmission 42. For example, the input rotor of the fifth transmission is provided on the outer circumferential surface of the intermediate shaft 36 and configured to rotate integrally with the intermediate shaft 36. The output rotor of the fifth transmission has a different diameter from the input rotor of the fifth transmission and is a rotor provided on the motor output shaft 18. For example, the output rotor of the fifth transmission has a larger diameter than the input rotor of the fifth transmission. For example, the output rotor of the fifth transmission is arranged on the outer circumferential surface of the motor output shaft 18 and configured to be rotatable relative to the motor output shaft 18. The endless annular portion of the fifth transmission is a member wound around the input rotor of the fifth transmission and the output rotor of the fifth transmission. The input rotor of the fifth transmission and the output rotor of the fifth transmission are connected by an endless annular member of the fifth transmission so as to rotate together.
For example, the sixth transmission is disposed in the internal space SA of the housing 14 and is provided in the housing 14. For example, the sixth transmission includes an input rotor, an output rotor, and an endless annular member. For example, the sixth transmission changes the rotational speed of the input rotor of the sixth transmission to rotate the output rotor of the sixth transmission. The input rotor of the sixth transmission is disposed coaxially with the motor output shaft 18 and is a rotor to which driving force is input from the output rotor of the fifth transmission. The input rotor of the sixth transmission is formed integrally with the output rotor of the fifth transmission. For example, the input rotor of the sixth transmission is provided on the outer peripheral surface of the intermediate shaft 36 and configured to rotate integrally with the intermediate shaft 36. The output rotor of the sixth transmission has a different diameter from the input rotor of the sixth transmission and is provided on the motor output shaft 18. For example, the output rotor of the sixth transmission has a larger diameter than the input rotor of the sixth transmission. For example, the output rotor of the sixth transmission is disposed on the outer peripheral surface of the motor output shaft 18 and is configured to be rotatable relative to the motor output shaft 18. The endless annular portion of the sixth transmission is a member that is wound around the input rotor of the sixth transmission and the output rotor of the fifth transmission. For example, the input rotor 44A of the fourth transmission 44 is configured to rotate integrally with the output rotor of the sixth transmission.
For example, if the second transmission 40 is selected as the first transmission section and the fifth transmission is selected as the second transmission section, the first output rotor and the second output rotor are provided on the intermediate shaft 36 so as to be rotatable relative to the motor output shaft 18.

As used herein, the phrase "at least one" means "one or more" of the desired options. As an example, when the number of options is two, the phrase "at least one" means "only one option" or "both of two options." As another example, when the number of options is three or more, the phrase "at least one" means "only one option" or "any combination of two or more options."

10...drive unit, 12...input rotating shaft, 14...housing, 22...input portion, 24...reduction gear, 26...output portion, 30...first one-way clutch, 34...second one-way clutch.

Claims (13)

A drive unit for a human-powered vehicle,
Housing and
a motor mounted in the housing and configured to provide a propulsive force to the human-powered vehicle;
an input portion provided in the housing and configured to receive a driving force from the motor ;
a first transmission unit provided in the housing, to which the driving force is input via the input unit;
an output unit provided in the housing and configured to be rotatable, to which the driving force is input via the first transmission unit;
an intermediate shaft on which a part of the first transmission unit is provided,
the motor includes a motor output shaft;
the intermediate shaft is offset from the motor output shaft and the output portion and is substantially parallel to the motor output shaft;
the first transmission unit includes a first input rotor, a first output rotor having a diameter different from that of the first input rotor, and a first endless annular member wound around the first input rotor and the first output rotor,
the first endless annular member includes a plurality of first engagement portions that are engaged with the first input rotor and the first output rotor, respectively, and that have a first pitch width in an extension direction of the first endless annular member;
the first pitch width is equal to or greater than 4 mm and equal to or less than 10 mm,
a second transmission unit provided in the housing and receiving the driving force via the first transmission unit;
the driving force is input to the output portion via the second transmission portion,
the second transmission unit includes a second input rotor, a second output rotor having a diameter different from that of the second input rotor, and a second endless annular member wound around the second input rotor and the second output rotor,
the second endless annular member includes a plurality of second engagement portions that are engaged with the second input rotor and the second output rotor, respectively, and that have a second pitch width in an extension direction of the second endless annular member;
the second pitch width is equal to or greater than 4 mm and equal to or less than 10 mm,
A drive unit in which the first endless annular member and the second endless annular member are configured such that the pitch width of the first endless annular member or the second endless annular member increases the closer they are to the output section in the driving force transmission path . The drive unit of claim 1, wherein the first pitch width is 5 mm or more and 8 mm or less. The drive unit described in claim 1 or 2, wherein the first transmission section constitutes a reducer. The drive unit according to claim 1 , wherein the second pitch width is equal to or greater than 5 mm and equal to or less than 8 mm. The drive unit according to claim 1 , wherein the second transmission portion constitutes a reducer. a first input rotation central axis of the first input rotor, a first output rotation central axis of the first output rotor, a second input rotation central axis of the second input rotor, and a second output rotation central axis of the second output rotor are arranged substantially parallel to a first direction,
The drive unit according to claim 1 , wherein the first output rotor is offset from the second input rotor in the first direction and is arranged coaxially with the second input rotor. The drive unit according to claim 6 , wherein the second transmission portion is disposed between the first transmission portion and the output portion in the first direction. the first input rotor includes a first sprocket,
the first output rotor includes a second sprocket,
The drive unit according to claim 1 , wherein the first endless annular member includes a chain. the first input rotor includes a first pulley,
the first output rotor includes a second pulley,
The drive unit according to claim 1 , wherein the first endless annular member includes a belt. Further comprising a first one-way clutch,
The drive unit according to claim 1 , wherein the first one-way clutch is disposed in a transmission path of the driving force between the input part and the output part. an input rotation shaft provided in the housing and into which a manual driving force is input;
The drive unit according to claim 1 , wherein an input rotation center axis of the input rotation shaft is provided coaxially with an output rotation center axis of the output section. At least a portion of the input rotary shaft is accommodated in the housing,
12. The drive unit according to claim 11 , wherein at least a portion of the input rotary shaft accommodated in the housing has a length in the axial direction of the input rotary shaft of not less than 50 mm and not more than 70 mm. Further provided with a second one-way clutch,
13. The drive unit according to claim 11 , wherein the second one-way clutch is disposed between the input rotary shaft and the output part in a transmission path of the manual driving force.