JP2007298138A - Active differential gear unit - Google Patents

Abstract

An object of the present invention is to obtain an active differential gear device having excellent turning efficiency without interference between driving torque and turning torque.
A first carrier is coupled to rotate integrally with a second carrier. The first outer gear 20 is fixed to the vehicle body 1. The first sun gear 19 receives a rotation similar to the rotation input to the differential gear 6. The turning operation force from the turning motor 16 is input to the second outer gear 24. The rotation of the second sun gear 23 is transmitted to the first wheel shaft 2.
[Selection] Figure 1

Description

  The present invention relates to an active differential gear device used for transmission of a driving force and a turning operation force in a vehicle.

  A conventional differential gear device includes a differential gear having an operation limiting mechanism capable of adjusting a limit torque, a steering angle sensor, a plurality of wheel speed sensors, and a controller that controls the limit torque in accordance with signals from these sensors. Yes. The controller keeps the limit torque small until the slip ratio of the drive wheel reaches a predetermined value during low-speed turning of the vehicle, and applies a large limit torque when the slip ratio of the drive wheel reaches the predetermined value (for example, Patent Documents). 1).

JP-A-9-109722

  However, the conventional differential gear device as described above suppresses the generation of the yaw moment that prevents the turning after detecting the slip ratio, and is not a complete active control, so the turning efficiency can be sufficiently increased. There wasn't.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain an active differential gear device having excellent turning efficiency without interference between driving torque and turning torque.

  An active differential gear device according to the present invention is provided between a first wheel shaft provided with a first wheel and a second wheel shaft provided with a second wheel, for rotating the first and second wheels. Of the differential gear, the first sun gear, the first outer gear arranged coaxially with the first sun gear, the first planetary gear meshing with the first sun gear and the first outer gear, and the revolution of the first planetary gear. The first planetary gear mechanism having a first carrier rotated about the rotation center of the first sun gear, and the second sun gear, the second outer gear arranged coaxially with the second sun gear, the second sun gear, and the second outer gear mesh with each other. A second planetary gear mechanism having a second planetary gear and a second carrier rotated about the rotation center of the second sun gear by the revolution of the second planetary gear; When the second sun gear is an element corresponding to the first sun gear, the second outer gear is an element corresponding to the first outer gear, and the second carrier is an element corresponding to the first carrier, the first sun gear, the first outer gear, and the second The connecting element that is one of the one carriers is connected to rotate integrally with an element corresponding to the connecting element, and the connecting element is removed from the first sun gear, the first outer gear, and the first carrier. The fixing element that is one of the two is fixed to the vehicle body that rotatably supports the first and second wheel shafts, and the connecting element and the fixing element are excluded from the first sun gear, the first outer gear, and the first carrier. The input element receives a rotation similar to the rotation input as the driving force to the differential gear, and the element corresponding to the fixed element includes the first and second rotations. A turning operation force for turning the second wheel shaft is input, and rotation of an element corresponding to the input element is transmitted to one of the first and second wheel shafts. ing.

  According to the active differential gear device of the present invention, a turning moment can be applied without depending on the driving speed.

The best mode for carrying out the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
1 is a block diagram showing an active differential gear device according to Embodiment 1 of the present invention. In FIG. First and second wheel shafts 2 and 3 are rotatably supported on the vehicle body 1. The first and second wheel shafts 2 and 3 are arranged on the same axis. A first wheel 4 that rotates integrally with the first wheel shaft 2 is provided at a first end of the first wheel shaft 2. A second wheel 5 that rotates integrally with the second wheel shaft 3 is provided at a first end of the second wheel shaft 3.

  A differential gear 6 is provided between the second end of the first wheel shaft 2 and the second end of the second wheel shaft 3. The differential gear 6 includes a first differential large gear 7 that rotates integrally with the first wheel shaft 2, a second differential large gear 8 that rotates integrally with the second wheel shaft 3, and first and second differential large gears. 7, a differential small gear 9 that meshes with 7 and 8, a casing 10 that holds the differential small gear 9, a drive sprocket 11 that is fixed to the casing 10, and a first transmission sprocket 12 that is fixed to the casing 10.

  The casing 10 receives a travel driving force from a drive motor 13 that is a travel drive source. Specifically, the driving force of the driving motor 13 includes a driving motor sprocket 14 provided in the driving motor 13, a first chain 15 wound between the driving motor sprocket 14 and the driving sprocket 11, and the driving sprocket 11. Through the casing 10.

  A turning operation force from a turning motor 16 that is a turning drive source is input to the first wheel shaft 2 via a torque cancellation mechanism 17. The turning motor 16 is controlled according to the steering angle of a handle (not shown). The torque canceling mechanism 17 includes first and second planetary gear mechanisms 18a and 18b having the same gear configuration.

  The first planetary gear mechanism 18 a includes a first sun gear 19, a first outer gear 20 disposed coaxially with the first sun gear 19, a plurality of first planetary gears 21 that mesh with the first sun gear 19 and the first outer gear 20, and a first It has a first carrier 22 that holds the planetary gear 21 and is rotated about the rotation center of the first sun gear 19 by the revolution of the first planetary gear 21.

  The second planetary gear mechanism 18b includes a second sun gear 23, a second outer gear 24 disposed coaxially with the second sun gear 23, a plurality of second planetary gears 25 meshing with the second sun gear 23 and the second outer gear 24, and a second It has a second carrier 26 that holds the planetary gear 25 and is rotated about the rotation center of the second sun gear 23 by the revolution of the second planetary gear 25.

  The pitch circle diameter ratios of the second sun gear 23, the second outer gear 24, and the second planetary gear 25 are the same as the pitch circle diameter ratios of the first sun gear 19, the first outer gear 20, and the first planetary gear 21, respectively. In the torque canceling mechanism 17, the second sun gear 23 is an element corresponding to the first sun gear 19, the second outer gear 24 is an element corresponding to the first outer gear 20, and the second carrier 26 is an element corresponding to the first carrier 22. It is.

  Further, in the torque cancellation mechanism 17, any one of the first sun gear 19, the first outer gear 20, and the first carrier 22 is set as a connecting element. In addition, one of the two components excluding the connecting element from the first sun gear 19, the first outer gear 20, and the first carrier 22 is set as a fixed element, and the remaining one is set as an input element.

  In this example, the first carrier 22 is set as a connecting element, the first outer gear 20 is set as a fixed element, and the first sun gear 19 is set as an input element.

  The first carrier 22 that is a connecting element is connected to the second carrier 26 so as to rotate integrally with the second carrier 26 that is an element corresponding to the first carrier 22. The first outer gear 20 that is a fixing element is fixed to the vehicle body 1. The first sun gear 19 that is an input element receives a rotation similar to the rotation that is input to the differential gear 6 as a driving force.

  A second transmission sprocket 27 that rotates integrally with the first sun gear 19 is connected to the first sun gear 19. A second chain 28 is wound between the first and second transmission sprockets 12 and 27. The rotation input to the casing 10 is transmitted to the first sun gear 19 via the first transmission sprocket 12, the second chain 28 and the second transmission sprocket 27.

  The turning operation force from the turning motor 16 is input to the second outer gear 24 that is an element corresponding to the fixed element. A third transmission sprocket 29 that rotates integrally with the second outer gear 24 is fixed to the second outer gear 24. The driving force of the swing motor 16 is generated by the swing motor sprocket 30 provided in the swing motor 16, the third chain 31 wound between the swing motor sprocket 30 and the third transmission sprocket 29, and the third transmission sprocket 29. To the second outer gear 24.

  A fourth transmission sprocket 32 that rotates integrally with the second sun gear 23 is connected to the second sun gear 23. A wheel shaft sprocket 33 is fixed to the first wheel shaft 2. A fourth chain 34 is wound between the fourth transmission sprocket 32 and the wheel shaft sprocket 33. The rotation of the second sun gear 23 which is an element corresponding to the input element is transmitted to the first wheel shaft 2 via the fourth transmission sprocket 32, the fourth chain 34 and the wheel shaft sprocket 33.

  FIG. 2 is a perspective view showing an assembly example of the active differential gear device of FIG. In FIG. 2, the wheels 4 and 5, the motors 13 and 16, and the chains 15, 28, 31, and 34 are not shown. The active differential gear device is supported by first to fourth support plates 1 a to 1 d fixed to the vehicle body 1. The first outer gear 20 is fixed to the support plate 1c.

  FIG. 3 is an explanatory view showing a state of transmission of the drive torque when only the drive torque from the drive motor 13 is applied to the active differential gear device of FIG. 1, and FIG. 4 is a diagram of the active differential gear device of FIG. It is explanatory drawing which shows the mode of transmission of the turning torque at the time of giving only this turning torque.

  When only the driving torque is applied, the driving torque is distributed to the first and second wheels 4 and 5 without affecting the turning torque. On the other hand, when only the turning torque is applied, the turning torque is transmitted to the first wheel 4 without affecting the driving torque. Further, the turning torque is transmitted to the second wheel 5 by the differential gear 6 in the direction opposite to that of the first wheel 4.

  In the apparatus experimentally manufactured by the inventors, D1: D2 = 11: 6, S1: S2 = 1: 2, and S2: S3 = 11: 5 were set.

  FIG. 5 is an explanatory diagram showing how both torques are transmitted when both the driving torque and the turning torque are applied to the active differential gear device of FIG. In the figure, solid arrows indicate driving torque, and broken arrows indicate turning torque.

  According to such a configuration, an active differential gear device having excellent turning efficiency without interference between the drive torque and the turning torque can be obtained. Further, the turning moment can be independently controlled without depending on the driving speed, and the driving and turning control can be simplified. Further, the turning motor 16 can be a motor having a lower output than the drive motor 13, and power saving can be achieved as compared with the case where the driving and turning motors are mounted on the wheels 4 and 5.

  Furthermore, in the conventional differential gear device, the generation of the yaw moment that hinders turning after the slip ratio is detected is suppressed. However, in the active differential gear device of the first embodiment, the wheels 4 and 5 are connected to the theoretical rotational speed. Therefore, complete active control that prevents the occurrence of slip itself can be realized. Thereby, it can turn with the same radius irrespective of travel speed and road surface condition.

In the above example, the rotation of the second sun gear 23 is transmitted to the first wheel shaft 2, but may be transmitted to the second wheel shaft 3.
In the above example, the first carrier 22 is the connecting element, but the first sun gear 19 or the first outer gear 20 may be the connecting element. Similarly, the first carrier 22 or the first sun gear 19 may be a fixed element. Further, the first outer gear 20 or the first carrier 22 may be used as an input element.
Furthermore, the present invention can be applied to all vehicles such as two-wheeled vehicles (wheelchairs, etc.), three-wheeled vehicles, and four-wheeled vehicles.
Furthermore, the travel drive source is not limited to the drive motor 13 and may be, for example, an internal combustion engine. Similarly, the turning operation source is not limited to the turning motor 16.
In the above example, a combination of a sprocket and a chain is used for torque transmission. However, the present invention is not limited to this. For example, a combination of a pulley and a belt, or a combination of a plurality of gears may be used. .

It is a block diagram which shows the active differential gear apparatus by Embodiment 1 of this invention. It is a perspective view which shows the assembly example of the active differential gear apparatus of FIG. It is explanatory drawing which shows the mode of transmission of a drive torque at the time of giving only the drive torque from a drive motor to the active differential gear apparatus of FIG. It is explanatory drawing which shows the mode of transmission of the turning torque at the time of giving only the turning torque from a turning motor to the active differential gear apparatus of FIG. It is explanatory drawing which shows the mode of transmission of both torque at the time of giving both drive torque and turning torque to the active differential gear apparatus of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Vehicle body, 2 1st wheel shaft, 3 2nd wheel shaft, 4 1st wheel, 5 2nd wheel, 6 Differential gear, 18a 1st planetary gear mechanism, 19 1st sun gear (input element), 20 1st outer gear (Fixed element), 21 first planetary gear, 22 first carrier (connecting element), 18b second planetary gear mechanism, 23 second sun gear (element corresponding to input element), 24 second outer gear (corresponding to fixed element) Elements), 25 second planetary gear, 26 second carrier (elements corresponding to connecting elements).

Claims (1)

A differential that is provided between a first wheel shaft provided with a first wheel and a second wheel shaft provided with a second wheel, and that is input with a driving force for rotating the first and second wheels. gear,
The first sun gear, the first outer gear arranged coaxially with the first sun gear, the first planetary gear meshing with the first sun gear and the first outer gear, and the rotation center of the first sun gear by the revolution of the first planetary gear A first planetary gear mechanism having a first carrier rotated about the second planetary gear, a second sun gear, a second outer gear arranged coaxially with the second sun gear, the second planetary gear meshing with the second sun gear and the second outer gear. A second planetary gear mechanism having a gear and a second carrier rotated about the rotation center of the second sun gear by the revolution of the second planetary gear;
When the second sun gear is an element corresponding to the first sun gear, the second outer gear is an element corresponding to the first outer gear, and the second carrier is an element corresponding to the first carrier, the first sun gear, The connection element that is one of the first outer gear and the first carrier is connected to rotate integrally with an element corresponding to the connection element,
The first sun gear, the first outer gear, and the fixed element, which is one of the two of the first carrier excluding the connecting element, are mounted on a vehicle body that rotatably supports the first and second wheel shafts. Fixed,
The first sun gear, the first outer gear, and the input element excluding the coupling element and the fixed element from the first carrier receive a rotation similar to the rotation input as the driving force to the differential gear. And
A turning operation force for turning the first and second wheel shafts is input to an element corresponding to the fixed element,
An active differential gear device configured to transmit rotation of an element corresponding to the input element to one of the first and second wheel shafts.

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