CN220452547U

CN220452547U - Clutch device

Info

Publication number: CN220452547U
Application number: CN202322207653.4U
Authority: CN
Inventors: 常东生
Original assignee: Ningbo Haimande Measurement And Control Technology Co ltd
Current assignee: Ningbo Haimande Measurement And Control Technology Co ltd
Priority date: 2023-08-16
Filing date: 2023-08-16
Publication date: 2024-02-06
Anticipated expiration: 2033-08-16

Abstract

The utility model relates to a clutch device, which comprises a speed reducer assembly and at least one clutch assembly, wherein the speed reducer assembly is provided with a speed reducer box body, a power shaft and a first clutch disc. The clutch assembly comprises a clutch frame, a driving mechanism, an output shaft, a pre-pressing elastic piece, a second clutch disc, a rotating body and a cam disc, wherein the clutch frame is provided with fixed convex teeth, the cam disc is provided with movable convex teeth, the movable convex teeth and the fixed convex teeth are provided with matching surfaces which incline relatively, and two ends of the pre-pressing elastic piece are respectively abutted against the first clutch disc and the second clutch disc and pre-compressed. The first clutch disc and the second clutch disc are in toothed engagement connection so as to be in a transmission posture; alternatively, the pre-pressing elastic member pushes the second clutch plate to be separated from the first clutch plate to be in a separated posture. The fixed convex teeth and the movable convex teeth realize axial movement clutch when the cam plate rotates, the driving mechanism converts rotation into axial movement, the clutch action structure of the first clutch plate and the second clutch plate is simplified, and the size of the clutch assembly is reduced.

Description

Clutch device

Technical Field

The utility model relates to the technical field of power transmission, in particular to a clutch device.

Background

The clutch device is used as a functional component for transmitting and disconnecting power in the existing power system, and has good on-off control effect. The existing clutch device directly drives the clutch piece to move through a shifting fork mechanism or a telescopic structure so as to realize clutch and separation combination.

As disclosed in chinese patent CN105274783B, a clutch device of a speed reducing clutch and the speed reducing clutch, where the clutch device includes a driving motor, a driving wheel, a shifting fork rod and a clutch sleeve, the driving wheel forms a supporting surface for supporting one end of the shifting fork rod, the other end of the shifting fork rod is in spacing contact with the clutch sleeve, a height difference is arranged on the supporting surface formed by the driving wheel, and the driving wheel controls the shifting fork rod to move through the height difference during rotation of the driving motor shaft so as to drive the clutch sleeve to move up and down; the upper and lower ends of the clutch shaft sleeve are respectively provided with an upper spline tooth meshed with the upper fixed disk and a lower spline tooth meshed with the lower dewatering disk, at least one of the upper and lower spline teeth is provided with a damping device for providing meshing buffer force, and the left/right side of the upper spline tooth is an inclined plane, and the right/left side of the lower spline tooth is an inclined plane.

However, the whole structure of the shifting fork structure is complex in action, the occupied movable space is large, the whole structure size of the clutch is affected, and the clutch is caused to be bulky, so that improvement is needed.

Disclosure of Invention

To overcome the problems in the related art, embodiments of the present utility model provide a clutch device.

According to a first aspect of an embodiment of the present utility model, there is provided a clutch device including:

the speed reducer assembly is provided with a speed reducer box body, a power shaft extending out of the speed reducer box body and a first clutch disc fixed on the power shaft;

the clutch assembly comprises a clutch frame, a driving mechanism arranged on the clutch frame, an output shaft rotatably connected with the clutch frame, a pre-pressing elastic piece arranged along the axial direction of the output shaft, a second clutch disc, a rotating body and a cam disc, wherein the clutch frame comprises at least two fixed convex teeth which are arranged in a protruding way at intervals, the cam disc is provided with movable convex teeth matched with the fixed convex teeth, the movable convex teeth and the fixed convex teeth are provided with relatively inclined matching surfaces, and two ends of the pre-pressing elastic piece are respectively abutted against the first clutch disc and the second clutch disc and pre-pressed; wherein,

the cam disc rotates relative to the output shaft and slides along the matching surface under the action of forward driving force of the driving mechanism, the second clutch disc moves axially along the output shaft under the action of thrust of the cam disc and the rotator, and the first clutch disc and the second clutch disc are in toothed engagement connection so as to be in a transmission posture; or the driving mechanism drives the cam disc to rotate relative to the output shaft in a reverse direction, and the pre-pressing elastic piece pushes the second clutch disc to be separated from the first clutch disc so as to be in a separation posture.

In an embodiment, the cam plate comprises a plate body and at least one transmission plate protruding laterally from the plate body, the movable convex teeth protrude laterally from the plate body, the transmission plate is provided with a transmission hole, the driving mechanism is connected to the transmission hole in a plugging mode, and the direction of acting force applied to the cam plate by the driving mechanism is inclined relative to the axis direction of the transmission hole and is not intersected with the axis of the transmission hole.

In an embodiment, the driving mechanism comprises a power piece arranged on the clutch frame, a driving screw connected with the power piece and a movable piece connected with the driving screw, and the movable piece is movably inserted into the transmission hole.

In one embodiment, an annular guide groove is formed in one side of the cam plate, which is away from the movable convex teeth, and the rotating body is connected to the guide groove in a rolling manner.

In an embodiment, the clutch frame comprises a pipe body seat, an end cover seat connected with the pipe body seat in a plugging manner, a bearing body assembled with the end cover seat in an embedded manner, and a fixing seat fixed with the end cover seat, wherein the fixing teeth protrude from the surface of the end cover seat, the driving mechanism is provided with a rotating seat, and two sides of the rotating seat are respectively connected with the pipe body seat and the end cover seat in a plugging manner.

In one embodiment, the second clutch disc is connected with the output shaft through a sliding key; or, the second clutch disc is provided with a long hole along the radial direction, the length direction of the long hole is parallel to the axis direction of the output shaft, the output shaft is fixed with a pin shaft, and the pin shaft moves in the long hole.

In an embodiment, the second clutch disc comprises a sliding part and a flange part protruding out of the sliding part, the surface of the flange part protrudes out of a plurality of second transmission teeth, the first clutch disc is provided with a plurality of first transmission teeth surrounding the power shaft, and the second transmission teeth and the first transmission teeth are mutually matched and meshed in the transmission gesture.

In one embodiment, the second driving teeth are arranged in a triangular convex tooth structure.

In an embodiment, the sliding part is provided with a limiting groove, and the rotator is connected to the limiting groove in a rolling way.

In an embodiment, the clutch assemblies are symmetrically distributed on two sides of the speed reducer assembly, the first clutch plates are mounted on two ends of the power shaft, and each first clutch plate is matched with one clutch assembly.

The technical scheme provided by the embodiment of the utility model can comprise the following beneficial effects: the joint surface between the fixed convex teeth and the movable convex teeth is an inclined joint surface, so that axial movement clutch is realized when the cam plate rotates, the driving mechanism converts rotation of the cam plate into axial movement, the clutch action structure of the first clutch plate and the second clutch plate is simplified, and the size of the clutch assembly is reduced. The pre-pressing elastic piece provides elastic pre-tightening force to keep the first clutch disc and the second clutch disc in a separation trend, so that the clutch function is simplified and effective separation can be kept.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the utility model as claimed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the utility model and together with the description, serve to explain the principles of the utility model.

Fig. 1 is a schematic structural view of a clutch device according to an exemplary embodiment.

Fig. 2 is a schematic cross-sectional structure of a clutch device according to an exemplary embodiment.

Fig. 3 is an exploded structural schematic view of a clutch device according to an exemplary embodiment.

FIG. 4 is a schematic structural view of a clutch assembly according to an exemplary embodiment.

Fig. 5 is a schematic diagram illustrating a clutch assembly with a clutch carrier removed according to an exemplary embodiment.

Fig. 6 is a schematic diagram illustrating the connection of a drive mechanism to a cam plate according to an exemplary embodiment.

In the drawings, a speed reducer assembly 10; a speed reducer case 11; a power shaft 12; a first clutch plate 13; a first gear 131; a clutch assembly 20; an output shaft 21; clutch carrier 22; a tube base 221; a mounting boss 2211; an end cap seat 222; a protective tube 2221; a bearing body 223; a holder 224; fixed teeth 2241; a cam plate 23; a movable lobe 231; a mating surface 232; a drive plate 233; a tray 234; a rotor 24; a holder 241; steel ball 242; a second clutch plate 25; a second gear 251; a flange portion 252; a sliding portion 253; a long hole 254; a drive mechanism 26; a power member 261; a drive screw 262; a movable member 263; a rotating seat 264; the elastic member 27 is preloaded.

Description of the embodiments

Wherein the drawings are for illustrative purposes only and are shown in schematic, non-physical, and not intended to be limiting of the present patent; for the purpose of better illustrating embodiments of the utility model, certain elements of the drawings may be omitted, enlarged or reduced and do not represent the size of the actual product; it will be appreciated by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

The same or similar reference numbers in the drawings of embodiments of the utility model correspond to the same or similar components; in the description of the present utility model, it should be understood that, if the terms "upper", "lower", "left", "right", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, only for convenience in describing the present utility model and simplifying the description, rather than indicating or implying that the apparatus or elements being referred to must have a specific orientation, be constructed and operated in a specific orientation, so that the terms describing the positional relationships in the drawings are merely for exemplary illustration and should not be construed as limiting the present patent, and that the specific meaning of the terms described above may be understood by those of ordinary skill in the art according to specific circumstances.

In the description of the present utility model, unless explicitly stated and limited otherwise, the term "coupled" or the like should be interpreted broadly, as it may be fixedly coupled, detachably coupled, or integrally formed, as indicating the relationship of components; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between the two parts or interaction relationship between the two parts. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

As shown in fig. 1 to 3, the present utility model provides a clutch device, which includes a speed reducer assembly 10 and at least one clutch assembly 20 mounted to the speed reducer assembly 10, wherein the speed reducer assembly 10 is used as a power input mechanism, and the clutch assembly 20 is used as an on-off control mechanism for controlling power output. Optionally, the speed reducer assembly 10 is connected to a clutch assembly 20 to form a one-way on-off power output. Preferably, the clutch device is provided with two clutch assemblies 20, the speed reducer assembly 10 is connected with the two clutch assemblies 20 at the same time, and each clutch assembly 20 can be independently controlled and correspondingly outputs power, so that the control is convenient. Preferably, the clutch assemblies 20 are symmetrically disposed on both sides of the speed reducer assembly 10 to improve balance of power output and rationality of space layout.

The speed reducer assembly 10 is provided with a speed reducer box 11, a power shaft 12 extending out of the speed reducer box 11, and a first clutch disc 13 fixed on the power shaft 12, wherein the speed reducer box 11 is a rigid structural member. Preferably, power shaft 12 extends out of reducer housing 11 and toward both ends to form a power take-off connection for dual clutch assembly 20. That is, the first clutch plates 13 are mounted at both ends of the power shaft 12, and each first clutch plate 13 is matched with one clutch assembly 20.

The clutch assembly 20 is mounted to the speed reducer housing 11 and cooperates with the first clutch plate 13. The clutch assembly 20 includes a clutch carrier 22, a driving mechanism 26 mounted on the clutch carrier 22, an output shaft 21 rotatably connected to the clutch carrier 22, a preload spring 27 mounted along an axial direction of the output shaft 21, a second clutch plate 25, a rotor 24, and a cam plate 23, the preload spring 27, the second clutch plate 25, the rotor 24, and the cam plate 23 being sequentially distributed along the axial direction of the output shaft 21. The pre-compression elastic member 27 is disposed around the output shaft 21, one end of the pre-compression elastic member abuts against the first clutch disc 13, the other end of the pre-compression elastic member abuts against the second clutch disc 25, and the distance between the first clutch disc 13 and the second clutch disc 25 is smaller than the length of the pre-compression elastic member 27, so that the pre-compression elastic member 27 has pre-compression. Accordingly, the first clutch plate 13 and the second clutch plate 25 have a tendency to be separated from each other by the elastic force of the pre-pressing elastic member 27. Preferably, the pre-compression spring 27 is configured as a spring.

The second clutch plate 25 is slidably connected to the output shaft 21, and the second clutch plate 25 is abutted against the cam plate 23 via the rotor 24. The rotor 24 is used to keep the second clutch plate 25 rotating independently and not to generate extrusion friction with the cam plate 23, so that the second clutch plate 25 can drive the output shaft 21 to rotate and transmit torque force. The rotor 24 cuts off the power transmission between the second clutch plate 25 and the cam plate 23, and the rotor 24 is optionally configured as a bearing or a rolling ball. Preferably, the rotor 24 includes a cage 241 and a plurality of steel balls 242 constrained to the cage 241, the steel balls 242 supporting the second clutch plate 25 and the cam plate 23.

The clutch frame 22 includes at least two fixing lugs 2241 provided to be protruded at intervals, and the at least two fixing lugs 2241 are provided to be spaced around the output shaft 21. Optionally, at least two stationary teeth 2241 are evenly distributed around clutch carrier 22. The cam plate 23 is abutted against the clutch frame 22, the cam plate 23 is provided with movable teeth 231 which are matched with fixed teeth 2241, and the movable teeth 231 and the fixed teeth 2241 have relatively inclined mating surfaces 232.

The cam disc 23 rotates relative to the output shaft 21 and slides along the mating surface 232 under the action of the forward driving force of the driving mechanism 26, the cam disc 23 rotates and moves along the axial direction of the cam disc 23 under the action of the relative extrusion of the fixed convex teeth 2241 and the movable convex teeth 231, and the cam disc 23 pushes the rotator 24 and the second clutch disc 25 to move. The second clutch plate 25 moves axially along the output shaft 21 under the thrust of the cam plate 23 and the rotator 24, and the first clutch plate 13 and the second clutch plate 25 are engaged with each other in a tooth-shaped manner so as to be in a transmission posture. Further, the driving mechanism 26 reversely drives the cam plate 23 to rotate with respect to the output shaft 21, while the pre-pressing elastic member 27 urges the second clutch plate 25 to be separated from the first clutch plate 13 to be in the separated posture.

The joint surface between the fixed tooth 2241 and the movable tooth 231 is an inclined matching surface 232, so that axial movement clutch is realized when the cam plate 23 rotates, the driving mechanism 26 converts the rotation of the cam plate 23 into axial movement, the clutch action structure of the first clutch plate 13 and the second clutch plate 25 is simplified, and the size of the clutch assembly 20 is reduced. The pre-compression spring 27 provides a spring pre-compression force to keep the first clutch plate 13 and the second clutch plate 25 in a separated trend, simplifying a clutch function and being able to keep effective separation.

As shown in fig. 3 to 6, the cam plate 23 is approximately of a disc-shaped structure, and in one embodiment, the cam plate 23 includes a plate body 234 and at least one drive plate 233 protruding laterally from the plate body 234, with movable teeth 231 protruding from the plane of the plate body 234. The disc 234 is provided with a through sliding hole, and the output shaft 21 is inserted into the sliding hole, so that the cam disc 23 slides along the output shaft 21. The drive plate 233 is provided with a drive hole to which the drive mechanism 26 is plug-in connected, and the direction of the force applied by the drive mechanism 26 to the cam plate 23 is inclined relative to the axial direction of the drive hole and is not intersecting the axis of the drive hole.

The telescopic movement of the driving mechanism 26 drives the driving plate 233 to rotate relative to the center line of the sliding hole, so that the movable convex tooth 231 slides along the matching surface 232 and moves axially. Wherein the cam plate 23 is moved relative to the driving mechanism 26 through the sliding hole, i.e., the cam plate 23 is moved relative to the driving mechanism 26 while rotating, to achieve synchronous movement.

Preferably, the driving plate 233 is provided with two driving mechanisms 26, and the driving mechanism 26 comprises a power piece 261 mounted on the clutch frame 22, a driving screw 262 connected to the power piece 261, and a movable piece 263 connected to the driving screw 262, wherein the movable piece 263 is movably inserted into the driving hole. The two ends of the movable member 263 are connected to the two driving plates 233 in a plugging manner, and the cam plate 23 can move along the axial direction of the movable member 263 and can rotate relative to the movable member 263. The driving screw 262 is in threaded connection with the movable member 263 to construct a threaded driving and self-locking positioning, and the power member 261 is configured as a motor structure. Alternatively, the axes of the drive screws 262 may be spatially disjoint with respect to the axis of the output shaft 21, perpendicular on the same projection plane. Alternatively, the axes of the drive screws 262 may be spatially disjoint with respect to the axis of the output shaft 21, intersecting parallel or extending lines on the same projection plane.

The clutch frame 22 is fixedly connected to the speed reducer box 11, wherein the clutch frame 22 comprises a pipe body seat 221, an end cover seat 222 connected to the pipe body seat 221 in a plugging manner, a bearing body 223 embedded and assembled in the end cover seat 222, and a fixing seat 224 fixed to the end cover seat 222, and fixing teeth 2241 protrude from the surface of the fixing seat 224. The driving mechanism 26 is provided with a rotating seat 264, and two sides of the rotating seat 264 are respectively inserted into the connecting pipe body seat 221 and the end cover seat 222.

The tube body seat 221 is similar to a tubular structure, the end cover seat 222 is closed at one end of the tube body seat 221, and the other end of the tube body seat 221 is assembled to the speed reducer body 11, so that the assembly of internal components is facilitated. The end cover seat 222 has a groove-shaped mounting groove, the output shaft 21 is assembled with the bearing body 223, the bearing body 223 is assembled in the mounting groove, and the fixing seat 224 is sleeved on the output shaft 21 and is sealed in the opening of the mounting groove. The fixing seat 224, the bearing body 223 and the output shaft 21 are mounted to the end cover seat 222, and then integrally mounted to the pipe body seat 221 through the end cover seat 222.

Preferably, the power member 261 is hinge-mounted to the rotating seat 264, and both sides of the rotating seat 264 are provided with protruding rotating shafts. The tube housing 221 is provided with a mounting boss 2211 protruding from the inner wall surface, and the mounting boss 2211 is provided with a mounting hole. The end cover seat 222 is provided with a rotation hole coaxial with the installation hole, and in the process of integrally installing the end cover seat 222 to the pipe body seat 221, a rotation shaft of the rotation seat 264 is inserted into the installation hole, and the other rotation shaft is inserted into the rotation hole, so that rotatable output power of the power piece 261 is realized.

As shown in fig. 1 to 4, optionally, the end cap base 222 further includes a protection tube 2221 partially protruding from the end surface, the section of the protection tube 2221 is in a "C" shape, and the transmission plate 233 passes through the notch of the protection tube 2221 and is connected to the movable element 263. The rotor 24, the cam plate 23 and a part of the second clutch plate 25 are all located in the protection tube 2221 to realize protection and guiding stability.

The second clutch plate 25 is slidably connected to the output shaft 21 for directional torque transfer. In an embodiment, the second clutch plate 25 is connected to the output shaft 21 by a sliding key, i.e. the output shaft 21 is provided with a splined portion and the second clutch plate 25 is provided with a matching splined hole. Alternatively, the output shaft 21 is provided with a flat key portion and the second clutch plate 25 is provided with a matching flat key slot.

In another embodiment, the second clutch plate 25 is provided with a long hole 254 along the radial direction, the length direction of the long hole 254 is parallel to the axial direction of the output shaft 21, the output shaft 21 is fixed with a pin, and the pin moves in the long hole 254. The second clutch plate 25 is provided with a long hole 254 and slides along the output shaft 21 to satisfy the stroke required for the clutch motion. The pin shaft drives the output shaft 21 to rotate when the second clutch plate 25 receives the torque force of the first clutch plate 13, thereby realizing power output.

As shown in fig. 3 to 6, in an embodiment, the second clutch plate 25 includes a sliding portion 253 and a flange portion 252 protruding the sliding portion 253, and the sliding portion 253 has a cylindrical structure for smoothly guiding the second clutch plate 25 to slide. Alternatively, the sliding portion 253 is provided with a movement hole penetrating to the flange portion 252, the long hole 254 communicates with the movement hole, the output shaft 21 is slidably connected to the movement hole, and the pin is located in the long hole 254.

The cross-sectional area of the flange portion 252 is larger than the cross-sectional area of the sliding portion 253, and of course, the cross-sectional area of the flange portion 252 is smaller than or equal to the cross-sectional area of the sliding portion 253, and may be provided without affecting the functionality. The flange 252 has a surface projecting with a plurality of second teeth 251, and the first clutch disk 13 is provided with a plurality of first teeth 131 surrounding the power shaft 12, the second teeth 251 and the first teeth 131 being engaged with each other in a driving posture. The second transmission teeth 251 and the first transmission teeth 131 are meshed in a tooth shape, so that power can be transmitted, and the power loss is small. Preferably, the second transmission teeth 251 are arranged in a triangular convex tooth structure, so that automatic alignment can be realized. The number of the second transmission teeth 251 is set to be more than ten to realize a small tooth engagement structure.

The rotor 24 is located between the second clutch plate 25 and the cam plate 23, wherein the sliding portion 253 is provided with a limiting groove, and the rotor 24 is connected to the limiting groove in a rolling manner. The cam disc 23 is provided with an annular guide groove on the side facing away from the movable tooth 231, to which the rotor 24 is connected in a rolling manner. The rotator 24 adopts the retainer 241 and the plurality of steel balls 242 distributed on the retainer 241, wherein the steel balls 242 on two sides of the retainer 241 are partially limited in the limiting groove and the guiding groove respectively, the eccentric amount is small, the automatic centering of the second clutch disc 25 and the cam disc 23 can be realized, the rotation flexibility is high, and the limiting effect is good.

Other embodiments of the utility model will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the utility model following, in general, the principles of the utility model and including such departures from the present disclosure as come within known or customary practice within the art to which the utility model pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the utility model being indicated by the following claims.

It is to be understood that the utility model is not limited to the precise arrangements and instrumentalities shown in the drawings, which have been described above, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the utility model is limited only by the appended claims.

Claims

1. A clutch device, comprising:

2. The clutch device according to claim 1, wherein the cam plate includes a plate body and at least one transmission plate protruding laterally from the plate body, the movable teeth protruding laterally from the plate body, the transmission plate being provided with a transmission hole, the driving mechanism being connected to the transmission hole in a plug-in manner, and a direction of a force applied to the cam plate by the driving mechanism being inclined relative to an axial direction of the transmission hole and not intersecting an axis of the transmission hole.

3. The clutch device according to claim 2, wherein the driving mechanism comprises a power member mounted on the clutch frame, a driving screw connected to the power member, and a movable member connected to the driving screw, and the movable member is movably inserted into the transmission hole.

4. A clutch device according to claim 2, characterised in that the side of the cam disc facing away from the movable tooth is provided with an annular guide groove, to which the rotor is in rolling connection.

5. The clutch device according to claim 1, wherein the clutch frame comprises a tube body seat, an end cover seat connected to the tube body seat in a plugging manner, a bearing body embedded and assembled in the end cover seat, and a fixing seat fixed on the end cover seat, the fixing convex teeth protrude from the surface of the end cover seat, the driving mechanism is provided with a rotating seat, and two sides of the rotating seat are respectively connected with the tube body seat and the end cover seat in a plugging manner.

6. The clutch device according to claim 1, wherein the second clutch disc is connected with the output shaft by a sliding key; or, the second clutch disc is provided with a long hole along the radial direction, the length direction of the long hole is parallel to the axis direction of the output shaft, the output shaft is fixed with a pin shaft, and the pin shaft moves in the long hole.

7. The clutch device according to claim 6, wherein the second clutch plate includes a sliding portion and a flange portion protruding from the sliding portion, a surface of the flange portion protrudes from a plurality of second transmission teeth, the first clutch plate is provided with a plurality of first transmission teeth surrounding the power shaft, and the second transmission teeth and the first transmission teeth are in mating engagement with each other in the transmission posture.

8. The clutch device of claim 7, wherein the second drive teeth are provided in a triangular tooth configuration.

9. The clutch device according to claim 6, wherein the sliding portion is provided with a limit groove, and the rotating body is rollably connected to the limit groove.

10. The clutch device according to any one of claims 1 to 9, wherein the clutch assemblies are symmetrically arranged on both sides of the speed reducer assembly, the first clutch plates are mounted on both ends of the power shaft, and each first clutch plate is matched with one clutch assembly.