Disclosure of Invention
In view of the above problems, the present invention is to provide a compound planetary transmission reducer and a driving unit, so as to solve the problem that the existing reducer has a transmission gap or is easy to vibrate.
The invention provides a compound planetary transmission speed reducer which comprises a sun gear, a sun friction wheel, a first annular gear, a first inner friction wheel, a second annular gear and a second inner friction wheel, wherein the sun gear is arranged on the sun gear; the first annular gear is arranged on the periphery of the sun gear, and a first planet wheel is connected between the sun gear and the first annular gear in a meshed mode; the first inner friction wheel is arranged on the periphery of the sun friction wheel, and a first planet friction wheel is connected between the sun friction wheel and the first inner friction wheel in a meshed manner;
the planetary gear transmission mechanism comprises a first planetary gear, a second planetary friction wheel and a second planetary gear, wherein one side of the first planetary gear is provided with the second planetary friction wheel and the second planetary gear, the second annular gear is arranged on the periphery of the second planetary gear and meshed with the second planetary gear, and the second inner friction wheel is arranged on the periphery of the second planetary friction wheel and meshed with the second planetary friction wheel.
Furthermore, it is preferable that the sun gear and the sun friction wheel form a series structure, the first planet wheel and the first planet friction wheel form a series structure, the first ring gear and the first inner friction wheel form a series structure, the second ring gear and the second inner friction wheel form a series structure, and the second planet wheel and the second planet friction wheel form a series structure.
In addition, the device preferably further comprises an input shaft and an output shaft which are connected with each other in a rotating way; wherein,,
the sun gear and the sun friction gear are arranged on the input shaft and are fixedly connected in series through a flat key; the first planetary friction wheel, the second planetary friction wheel and the second planetary wheel are arranged on the shaft of the first planetary wheel and are fixedly connected in series through a flat key;
the second inner gear ring is fixed with the second inner friction wheel, and the second inner friction wheel is fixed with the output shaft.
In addition, the preferred scheme is that the outer circular surface of the sun friction wheel is an inner cambered surface, the outer circular surface of the first planetary friction wheel and the outer circular surface of the second planetary friction wheel are both outer cambered surfaces, and the inner circular surface of the first inner friction wheel and the inner circular surface of the second inner friction wheel are both inner cambered surfaces.
In addition, the preferred scheme still includes the casing, first ring gear with first interior friction wheel all with casing fixed connection, the second interior friction wheel with the casing rotates to be connected.
In addition, the planetary gear system preferably further comprises a planetary carrier and a planetary carrier support, wherein the first planetary gear is rotatably connected with the planetary carrier, and the planetary carrier is rotatably connected with the planetary carrier support and the input shaft respectively.
In addition, a spring is preferably sleeved on the input shaft, and the spring is limited between the planet carrier and the sun gear.
In addition, a first bearing seat is arranged on one side of the shell, the input shaft is rotationally connected with the first bearing seat, a force sensor is arranged in the first bearing seat, a stator of the voice coil motor is arranged on the force sensor, and a rotor of the voice coil motor is connected with the planet carrier through a thrust bearing;
the other side of the shell is provided with a second bearing seat, and the output shaft is rotationally connected with the second bearing seat.
In addition, it is preferable that an auxiliary support friction wheel is rotatably connected to the input shaft, and the auxiliary support friction wheel is meshed with the second planetary friction wheel; and, in addition, the processing unit,
the outer circular surface of the auxiliary supporting friction wheel is an inner cambered surface.
On the other hand, the invention also provides a driving unit which comprises the compound planetary transmission speed reducer.
Compared with the prior art, the compound planetary transmission speed reducer has the following beneficial effects:
the composite planetary transmission speed reducer combining friction transmission and gear transmission provided by the invention integrates the advantages of large bearing capacity, high transmission efficiency, accurate transmission ratio and low noise of planetary gear transmission, has a simple structure, can realize gapless forward and reverse transmission, can realize bidirectional transmission, can avoid transmission gaps of the speed reducer, and is an ideal transmission system of various robots and driving units.
To the accomplishment of the foregoing and related ends, one or more aspects of the invention comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative aspects of the invention. These aspects are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Furthermore, the invention is intended to include all such aspects and their equivalents.
Drawings
Other objects and results of the present invention will become more apparent and readily appreciated by reference to the following description and claims in conjunction with the accompanying drawings and a more complete understanding of the invention. In the drawings:
FIG. 1 is a schematic diagram of a compound planetary transmission reducer according to an embodiment of the invention;
FIG. 2 is a schematic cross-sectional view of a compound planetary transmission reducer according to an embodiment of the invention;
FIG. 3 is a cross-sectional view of a compound planetary drive reducer in accordance with an embodiment of the invention;
FIG. 4 is a side cross-sectional view of a compound planetary transmission reducer in the A-A position in accordance with an embodiment of the invention;
FIG. 5 is a side cross-sectional view of a compound planetary transmission reducer in the B-B position in accordance with an embodiment of the invention;
FIG. 6 is a side cross-sectional view of a compound planetary transmission reducer in the C-C position in accordance with an embodiment of the invention;
FIG. 7 is a side cross-sectional view of a compound planetary transmission reducer in the D-D position in accordance with an embodiment of the invention;
reference numerals: sun gear S, sun gear FS, first ring gear R1, second ring gear R2, first inner gear FR1, first planetary gear P1, second planetary gear P2, first planetary gear FP1, second planetary gear FP2, input shaft 100, output shaft 200, carrier 300, force sensor 400, auxiliary supporting friction wheel 500, spring 600, casing 700, carrier support 800, thrust bearing 900, second bearing housing 110, stator M1, mover M2.
The same reference numerals will be used throughout the drawings to refer to similar or corresponding features or functions.
Detailed Description
In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It may be evident, however, that such embodiment(s) may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing one or more embodiments.
Fig. 1 shows the principle of a compound planetary transmission reducer according to an embodiment of the present invention, fig. 2 shows a front sectional structure of the compound planetary transmission reducer according to an embodiment of the present invention, fig. 3 shows a cross-sectional marking structure of the compound planetary transmission reducer according to an embodiment of the present invention, fig. 4 shows a side sectional structure of the compound planetary transmission reducer according to an embodiment of the present invention at A-A position, fig. 5 shows a side sectional structure of the compound planetary transmission reducer according to an embodiment of the present invention at B-B position, fig. 6 shows a side sectional structure of the compound planetary transmission reducer according to an embodiment of the present invention at C-C position, and fig. 7 shows a side sectional structure of the compound planetary transmission reducer according to an embodiment of the present invention at D-D position.
As can be seen from the common illustration of fig. 1 to 7, the composite planetary transmission reducer provided by the present invention adopts a configuration in which planetary gear transmission and planetary friction wheel transmission are connected in series, wherein a planetary gear transmission portion includes a sun gear S, a first ring gear R1, a second ring gear R2, a first planetary gear P1 and a second planetary gear P2, and a planetary friction wheel transmission portion includes a sun friction wheel FS, a first inner friction wheel FR1, a second inner friction wheel FR2, a first planetary friction wheel FP1 and a second planetary friction wheel FP2.
Specifically, the meshing relationship of each component in the compound planetary transmission reducer provided by the invention is as follows: the first inner gear ring R1 is arranged on the periphery of the sun gear S, and the first planet gears P1 are connected between the sun gear S and the first inner gear ring R1 in a meshed manner; the first inner friction wheel FR1 is arranged on the periphery of the sun friction wheel FS, and the first planetary friction wheel FP1 is connected between the sun friction wheel FS and the first inner friction wheel FR1 in a meshed manner; the second planetary friction wheel FP2 and the second planetary gear P2 are disposed at one side of the first planetary gear P1 (or the first planetary friction wheel FP 1), the second ring gear R2 is disposed at the outer periphery of the second planetary gear P2 and engaged with the second planetary gear P2, and the second inner friction wheel FR2 is disposed at the outer periphery of the second planetary friction wheel FP2 and engaged with the second planetary friction wheel FP2.
In addition, the components in the compound planetary transmission reducer provided by the invention have the following connection relation: the sun gear S and the sun friction wheel FS form a serial structure, the first planet wheel P1 and the first planet friction wheel FP1 form a serial structure, the first annular gear R1 and the first inner friction wheel FR1 form a serial structure, the second annular gear R2 and the second inner friction wheel FR2 form a serial structure, and the second planet wheel P2 and the second planet friction wheel FP2 form a serial structure.
It should be noted that, in the compound planetary transmission reducer provided by the present invention, the series structure, that is, the two components are in a coaxial and synchronous mutual fixed relationship, that is, a coaxial and synchronous mutual fixed relationship between the sun gear S and the sun friction wheel FS, between the first planet gear P1 and the first planet friction wheel FP1, between the first ring gear R1 and the first inner friction wheel FR1, between the second ring gear R2 and the second inner friction wheel FR2, and between the second planet gear P2 and the second planet friction wheel FP2.
In one embodiment of the present invention, the compound planetary transmission reducer provided by the present invention further comprises an input shaft 100 and an output shaft 200 (rotatably connected by a bearing) rotatably connected to each other; wherein, the sun gear S and the sun friction gear FS are both arranged on the input shaft 100, and are both fixed on the input shaft 100 in series through a flat key; the first planetary friction wheel FP1, the second planetary friction wheel FP2 and the second planetary wheel P2 are all arranged on the shaft of the first planetary wheel P1, and the four planetary wheels are fixedly connected in series through a flat key, so that the required coaxial synchronous relationship is realized; the second ring gear R2 is fixedly connected with the second inner friction wheel FR2, and the second inner friction wheel FR2 is fixedly connected with the output shaft 200.
More specifically, to improve the support protection of the compound planetary transmission reducer provided by the invention, the compound planetary transmission reducer provided by the invention further comprises a casing 700, the first annular gear R1 and the first inner friction wheel FR1 are fixedly connected with the casing 700 (or are in an integral structure with the casing 700) through components such as screws, and the second inner friction wheel FR2 and the casing 700 are rotatably connected through bearings.
In addition, in order to improve the transmission effect between the friction wheels, the outer circumferential surface of the sun friction wheel FS may be set to an inner circumferential surface, the outer circumferential surface of the first planetary friction wheel FP1 and the outer circumferential surface of the second planetary friction wheel FP2 are both set to outer circumferential surfaces corresponding to the inner circumferential surfaces, and the inner circumferential surface of the first inner friction wheel FR1 and the inner circumferential surface of the second inner friction wheel FR2 are both set to the inner circumferential surfaces, so that the transmission effect between the friction wheels is improved by matching the inner circumferential surfaces with the outer circumferential surfaces in the actual transmission process.
In addition, to further improve the support stability of each planet, the compound planetary transmission reducer provided by the invention may further include a planet carrier 300 and a planet carrier support 800, where the first planet wheel P1 (and the second planet carrier, the first planet friction wheel FP1, and the second planet friction wheel FP 2) are rotatably connected to the planet carrier 300 (may be rotatably connected through bearings) and are uniformly distributed and uniformly loaded along the circumference by the planet carrier 300, and the planet carrier 300 is rotatably connected to the planet carrier support 800 and the input shaft 100 through different bearings, respectively, and the planet carrier support 800 is located in the casing 700 and may be translated in the casing 700.
In a preferred embodiment of the present invention, to support the input shaft 100 and the output shaft 200, a first bearing housing (not shown) may be disposed on one side of the housing 700, the first bearing housing is fixedly connected to the housing 700, and the input shaft 100 is rotatably connected to the first bearing housing through a bearing; a second bearing seat 110 is provided at the other side of the housing 700, the second bearing seat 110 is fixedly connected with the housing 700, and the output shaft 200 is rotatably connected with the second bearing seat 110.
In addition, for the friction transmission, manual pre-tightening is needed periodically, the compound planetary transmission speed reducer provided by the invention provides a force sensor 400 for monitoring the pre-tightening force of each friction wheel in real time and realizing the automatic pre-tightening of each friction wheel. Specifically, a force sensor 400 may be disposed in the first bearing seat, for monitoring the pretightening force of the friction transmission, a stator M1 of a preset voice coil motor is disposed on the force sensor 400, and a mover M2 of the voice coil motor is connected to the planet carrier through a thrust bearing 900, so as to provide a necessary pretightening force for the friction transmission; when the pretightening force is lower than the preset value, the voice coil motor pushes the planet carrier 300 to move to pretighten the friction transmission, and the preset pretightening force is achieved.
In addition, in order to prevent the axial movement of the planet carrier when the voice coil motor is not in operation, a spring 600 may be sleeved on the input shaft 100, the spring 600 is coaxially sleeved on the input shaft 100, the spring 600 is limited between the planet carrier and the sun gear S, and a certain pre-compression is provided by arranging the spring 600 between the sun gear S and the planet carrier.
In another preferred embodiment of the present invention, the present invention provides a compound planetary transmission reducer that employs auxiliary support friction wheels 500 to balance the generated normal force against the problem that friction transmission generates a large normal force. Specifically, an auxiliary supporting friction wheel 500 is rotatably connected to the input shaft 100, and the auxiliary supporting friction wheel 500 is engaged with the second planetary friction wheel FP 2; and, the outer circumferential surface of the auxiliary supporting friction wheel 500 is also made into an inner arc surface adapted to the outer arc surface on the second planetary friction wheel FP2, and the normal force generated by the friction wheel set is balanced by providing the auxiliary supporting friction wheel 500.
It should be noted that, the auxiliary supporting friction wheel 500 is sleeved on the input shaft 100 through a bearing, and does not participate in transmission, but only plays a role of auxiliary supporting friction planetary wheels, so as to balance the normal force caused by friction transmission, thereby ensuring stable transmission.
In the actual transmission process, the transmission ratio of the planetary gear transmission part in the compound planetary transmission speed reducer provided by the invention is as follows:
wherein, the method comprises the steps of, wherein,the number of teeth of each gear.
The transmission ratio of the friction planetary transmission part is as follows:
wherein, the method comprises the steps of, wherein,is the diameter of the meshing excircle of the friction wheel.
The ratio of the two parts should satisfy the following relationship:
as can be seen from the above, the outer diameter at each friction wheel engagement point is equal to the diameter of the gear pitch circle in series therewith.
In addition, it should be noted that in the connection relationship between the components in the compound planetary transmission reducer provided in the embodiment of the present invention, the (relatively) rotatable connection between the two components is involved, and for the connection component for implementing such connection relationship, the connection component preferably used in the compound planetary transmission reducer provided in the present invention is a bearing, and for the specific structure in the bearing and the working principle thereof, the connection component is common knowledge in the art, and is described in many existing documents and is not repeated herein.
On the other hand, in order to illustrate the specific application field of the compound planetary transmission reducer provided by the invention, the invention also provides a driving unit (such as a driving unit of various robots), wherein the driving unit comprises the compound planetary transmission reducer; the speed reducer can enable the driving unit to realize high-efficiency motion output, supports forward and reverse driving of a large load, and has no transmission clearance.
As can be seen from the above specific embodiments of the present invention, the compound planetary transmission reducer and the driving unit provided by the present invention have at least the following advantages:
1. the composite planetary transmission speed reducer integrates the advantages of planetary gear transmission and friction transmission. The device is particularly suitable for driving units such as robots, mobile AGVs and the like which need larger transmission moment, high-efficiency forward and reverse transmission and higher motion output precision; the high-load and high-efficiency gapless forward and reverse transmission can be realized;
2. aiming at the transmission clearance caused by the backlash in the planetary gear transmission, the characteristics of zero-clearance transmission can be realized by friction planetary transmission, so that the motion output of speed reduction without transmission clearance can be realized, and the motion control precision of the speed reducer can be improved;
3. aiming at the problems that the friction planetary transmission needs to be pre-tightened periodically and has larger normal force, a force sensor is adopted to monitor the pre-tightening force value of the friction pair in real time, and the automatic pre-tightening of the friction pair is realized by controlling the displacement of the planet carrier through a voice coil motor by utilizing the characteristic that the planet carrier does not participate in torque transmission;
4. an auxiliary friction wheel is added to the second-stage friction planetary transmission to balance normal force, the auxiliary friction wheel is meshed with the second planetary friction wheel, and the auxiliary friction wheel is not involved in motion transmission through a bearing empty sleeve and an input shaft, so that the normal force can be effectively balanced.
The compound planetary transmission reducer and the drive unit according to the invention are described above by way of example with reference to fig. 1 to 7. However, it will be appreciated by those skilled in the art that various modifications may be made to the compound planetary transmission reducer and drive unit set forth above without departing from the teachings of the present invention. Accordingly, the scope of the invention should be determined from the following claims.