CN116919782A

CN116919782A - Driving device of wearable exoskeleton

Info

Publication number: CN116919782A
Application number: CN202210354775.3A
Authority: CN
Inventors: 请求不公布姓名
Original assignee: Yuanye Technology Suzhou Co ltd
Current assignee: Yuanye Technology Suzhou Co ltd
Priority date: 2022-04-06
Filing date: 2022-04-06
Publication date: 2023-10-24
Also published as: WO2023193463A1

Abstract

The invention discloses a driving device of a wearable exoskeleton, which comprises a driving module and a transmission module, wherein the driving module comprises a motor, the transmission module comprises a motor rotating shaft, a driving wheel and a driven wheel, the driving wheel is connected with the motor through the motor rotating shaft, the driven wheel is connected with the driving wheel, and the section of the driving wheel is non-circular. Particularly, the cross section of the driving wheel is of a multi-arc-shaped, three-arc-shaped or round-angle-shaped structure, so that the driving wheel can generate higher torque, the abrasion of the driving wheel and a sleeved part is reduced, high-torque support is provided, transmission power is better transmitted to the parts sleeved on the driving wheel, and the structural design is ingenious, so that the service life and transmission performance of the invention are improved; the bearing and the driven wheel fixing piece are arranged, so that the power transmission from the driving wheel to the driven wheel is softer and not hard, the safety is better, and the transmission noise is low. The invention has the advantages of reasonable transmission mode, difficult abrasion, long service life and good safety performance.

Description

Driving device of wearable exoskeleton

Technical Field

The invention relates to nerve, muscle and skeleton rehabilitation equipment, in particular to a driving device of a wearable exoskeleton with good transmission function.

Background

In the application scene of the exoskeleton at the present stage, the method mainly comprises two aspects: one is to improve the mobility of healthy people, and the other is to provide rehabilitation training and walking assistance for mobility impaired people.

The power control of the exoskeleton is realized by a driving device, the existing driving device of the wearable exoskeleton is simpler, the power is basically provided for the exoskeleton, particularly, the driving mode is unreasonable, hard and dangerous, the exoskeleton is easy to generate, the exoskeleton is not suitable for independent walking of a patient during rehabilitation training, the patient needs to assist by people, the integration level is low, the size is large, the weight is heavy, the heat dissipation performance is poor, the design does not accord with the ergonomics, and the performance is poor.

Accordingly, there is a need for a wearable exoskeleton driving device that overcomes or minimizes the above-described problems.

Disclosure of Invention

The invention aims to provide a driving device of a wearable exoskeleton, which has the advantages of reasonable transmission mode, difficult abrasion, long service life and good safety performance.

The driving device of the wearable exoskeleton comprises a driving module and a transmission module, wherein the driving module comprises a motor, the transmission module comprises a motor rotating shaft, a driving wheel and a driven wheel, the driving wheel is connected with the motor through the motor rotating shaft, the driven wheel is connected with the driving wheel, and the section of the driving wheel is non-circular.

The preferable scheme is that the section of the driving wheel is a multi-arc polygon.

In another preferable scheme, the section of the driving wheel is in a three-arc shape.

In a further preferred scheme, the cross section of the driving wheel is a Lailo triangle with the vertex led into a round angle.

In another preferred scheme, the driven wheel is provided with a pulley structure taking the driving wheel as the center.

The driving module further comprises a bearing, the driving wheel is connected with the driven wheel through the bearing, the inner ring of the driven wheel is sleeved with the outer ring of the bearing, and the inner ring of the bearing is sleeved with the outer ring of the driving wheel.

The transmission module further comprises a driven wheel fixing piece, wherein the driven wheel fixing piece is sleeved on the outer ring of the driving wheel, the shape of the inner ring of the driven wheel fixing piece is matched with the shape of the outer ring of the driving wheel to be sleeved with teeth, and the driven wheel is connected with the driven wheel fixing piece.

In another preferred scheme, the transmission module further comprises a traction wire, and the traction wire is connected with the driven wheel; the traction wire is provided as a bowden wire.

In another preferred scheme, one end of the bowden cable is fixedly arranged in a preset fixed groove of the driven wheel, and the bowden cable is fixed through a set pressing piece and a screw.

The driving wheel is fixedly connected with the motor rotating shaft through a driving wheel fixing screw; the driven wheel is fixedly connected with the driven wheel fixing piece through a driven wheel fixing piece fixing screw.

Compared with the prior art, the invention has the following advantages:

the section of the driving wheel is arranged to be non-circular, in particular to a structure of which the multi-arc shape, the three-arc shape or the top point is led into a round-angle Lailo triangle, so that the driving wheel can generate higher torque, reduce the abrasion of the driving wheel and the materials sleeved on the driving wheel and the materials of the parts, provide high torque support, and better transmit transmission power to all the parts sleeved on the driving wheel, and the driving wheel has ingenious structural design, so that the service life of the driving wheel is prolonged, and the transmission performance is improved; the arrangement of the bearing and the driven wheel fixing piece increases the axial stress bearable by the turntable, protects the bearing in the driving device, prolongs the service life of the motor, simultaneously ensures that the power transmission from the driving wheel to the driven wheel is softer and not hard, has better safety, and has the advantages of compactness, simplicity and low transmission noise.

Drawings

FIG. 1 is a functional block diagram of a driving device of a wearable exoskeleton of the present invention;

FIG. 2 is a schematic diagram of a driving device of a wearable exoskeleton of the present invention;

FIG. 3 is an exploded view of the driving device of the wearable exoskeleton of the present invention;

FIG. 4 is a schematic front view of the driving device of the wearable exoskeleton of the present invention;

FIG. 5 is a schematic view of the back of the driving device of the wearable exoskeleton of the present invention;

FIG. 6 is a schematic top view of a driving device of the wearable exoskeleton of the present invention;

FIG. 7 is a schematic bottom view of a driving device of a wearable exoskeleton of the present invention;

FIG. 8 is a schematic view of the housing structure of the driving device of the present invention;

FIG. 9 is a schematic diagram of a power module mounting structure of the driving device of the present invention;

fig. 10 is an exploded view of a battery module of the driving apparatus of the present invention;

FIG. 11 is a schematic cross-sectional view of a battery module in a driving apparatus according to an embodiment of the present invention;

FIG. 12 is a schematic view of a partial cross-sectional structure of a driving device according to an embodiment of the present invention;

FIG. 13 is a schematic cross-sectional view of a driving device according to an embodiment of the present invention;

FIG. 14 is a schematic view of a partial construction of the bottom spring of FIG. 13;

FIG. 15 is a schematic view showing the connection structure of the motor and the motor fixing member in the driving device of the present invention;

FIG. 16 is a schematic view showing a part of the structure of a motor at a fixed position in the driving device of the present invention;

FIG. 17 is a schematic view of the joint between the driving wheel, the pulley and the driven wheel in the embodiment of the invention;

FIG. 18 is a schematic view of a partial structure of an embodiment of the present invention with a driven wheel securing member installed;

FIG. 19 is a schematic view showing a connection and disconnection structure of a driven wheel and a traction wire according to an embodiment of the present invention;

FIG. 20 is a schematic cross-sectional view of a driving device with a light guiding column according to an embodiment of the present invention;

fig. 21 is a partial enlarged view of the light guide column of fig. 20.

Detailed Description

In order to further describe the technical means and effects adopted by the present invention to achieve the predetermined purpose, the following description refers to the specific implementation, structure, characteristics and effects of the driving device for a wearable exoskeleton according to the present invention with reference to the accompanying drawings and the preferred embodiments.

As shown in fig. 1, which is a functional module diagram of a driving device of a wearable exoskeleton of the present invention, the driving device of the wearable exoskeleton of the present invention includes a driving module, a transmission module, a battery module and a heat dissipation module, wherein the battery module provides power for the driving module, the transmission module is controlled by the driving module to move, and the heat dissipation module dissipates heat for the driving module. The modules are tightly matched and operated in coordination, so that the invention can effectively help the rehabilitation training of patients.

Referring to fig. 2, a schematic structural diagram of a driving device of the wearable exoskeleton of the present invention is shown, where the driving module includes a driving plate 11 and a motor 1; the heat dissipation module comprises a heat radiator 2, wherein the heat radiator 2 is connected with the motor 1 and the driving plate 11 to dissipate heat of the motor 1 and the driving plate 11. In the embodiment of the invention, the motor 1, the driving plate 11 and the same radiator 2 are connected, so that the motor 1 and the driving plate 11 are integrated into a whole and jointly generate heat, and only one radiator 2 is needed for radiating, thereby achieving the functions of saving cost, saving space, reducing weight and improving radiating efficiency.

Referring to fig. 3 for an exploded structure diagram of a driving device of a wearable exoskeleton of the present invention, fig. 17 for a schematic diagram of a connection between a driving wheel, a pulley and a driven wheel in an embodiment of the present invention, and fig. 19 for a schematic diagram of a connection between a driven wheel and a traction wire in an embodiment of the present invention, the transmission module includes a motor shaft 100, a driving wheel 101, a driven wheel 102 and a traction wire 107, the driven wheel 102 is configured as a pulley structure centered on the driving wheel 101, the driving wheel 101 is connected to the motor 1 through the motor shaft 100, and the traction wire 107 is connected to the driven wheel 102; the traction wire 107 is a bowden wire, one end of the bowden wire is fixedly installed in a preset fixing groove of the driven wheel 102, and the bowden wire is fixed through a pressing piece 109 and a screw.

Referring to fig. 2 and 3, the driving plate 11 is connected to the motor 1, the motor 1 is connected to the driving wheel 101 through a motor bearing 100, the driving wheel 101 is connected to the driven wheel 102, the driving plate 11 controls the power of the motor 1, including start and stop, and power, and the motion of the motor 1 is sequentially transmitted to the driving wheel 101 and the driven wheel 102 through a motor shaft 100.

Referring to fig. 4, a front schematic view of a driving device structure of the wearable exoskeleton of the present invention and fig. 7, a bottom schematic view of a driving device structure of the wearable exoskeleton of the present invention, in an embodiment of the present invention, the driving module further includes a main board 4, an upper bracket 6, a lower bracket 7, and a power board 15; the upper bracket 6 and the lower bracket 7 form a stable frame structure by respectively connecting locking motor fixing pieces 18, see fig. 2. Referring to fig. 2 and 6, which are schematic top views of the driving device structure of the wearable exoskeleton of the present invention, the upper bracket 6 is locked and fixed on the motor fixing member 18 by the upper bracket fixing screw 10; referring to fig. 2 and 7, the lower bracket 7 is fastened to the motor fixing member 18 by the lower bracket fixing screw 13.

Referring to fig. 2 and 15, a schematic diagram of a connection structure between a motor and a motor fixing member in a driving device according to the present invention is shown, wherein the motor 1 is connected to the motor fixing member 18, and the motor 1 is supported by a stable frame structure formed by the motor fixing member 18 and upper and lower brackets, so that the motor 1 is stable in the present invention. Referring to fig. 15 and 16, which are schematic views of a part of a motor fixing position in the driving device of the present invention, in an embodiment of the present invention, the motor 1 is fixed on a motor fixing member 18 by a motor fixing screw 17.

Referring to fig. 7, in the embodiment of the present invention, the power board 15 is locked and fixed with the lower bracket 7 by the power board fixing screws 16.

Referring to fig. 4, the main board 4 is locked and fixed with the heat sink 2 by the main board fixing screws 3.

Referring to fig. 6, in the embodiment of the present invention, the driving plate 11 is locked and fixed with the upper bracket 6 by a driving plate fixing screw 12.

Referring to fig. 3, the transmission module further includes a bearing 103, the driving wheel 101 is connected with the driven wheel 102 through the bearing 103, an inner ring of the driven wheel 102 is sleeved with an outer ring of the bearing 103, an inner ring of the bearing 103 is sleeved with an outer ring of the driving wheel 101, and a section of the driving wheel 101 is non-circular.

Referring to fig. 17 and 18, a schematic partial structure of the driven wheel fixing member is shown in the embodiment of the present invention, in which the cross section of the driving wheel 101 is a multi-arc triangle, preferably a tri-arc triangle, or the cross section of the driving wheel 101 is a leo triangle with rounded vertices. The cross section of the driving wheel 101 is in a non-circular shape, particularly in a structure of a multi-arc triangle, a tri-arc triangle or a Lai triangle with the vertex being rounded, so that the driving wheel 101 can generate higher torque, reduce the abrasion of the driving wheel 101 and materials sleeved on the driving wheel 101, provide high torque support, and better transmit transmission power to all the parts sleeved on the driving wheel, and the invention has smart structural design, thereby prolonging the service life and improving the transmission performance.

Referring to fig. 3, in the embodiment of the present invention, the transmission module further includes a driven wheel fixing member 104, the driven wheel fixing member 104 is sleeved on the outer ring of the driving wheel 101, the inner ring shape of the driven wheel fixing member 104 is engaged with the outer ring shape of the driving wheel 101 in a matching and engaging manner, and the driven wheel 102 is connected with the driven wheel fixing member 104. The arrangement of the bearing 103 and the driven wheel fixing piece 104 increases the axial stress bearable by the turntable, protects the bearing 103 in the driving device, prolongs the service life of the motor 1, and simultaneously ensures that the power transmission from the driving wheel 101 to the driven wheel 102 is softer and not harder, the safety is better, and the arrangement mode has the advantages of compactness, simplicity and low transmission noise.

Referring to fig. 3 and 17, in the embodiment of the present invention, a driving wheel 101 is fixedly connected to a motor shaft 100 through a driving wheel fixing screw 108; referring to fig. 3, 18 and 19, driven wheel 102 is fixedly coupled to driven wheel mount 104 by driven wheel mount set screws 106.

Thus, when the motor 1 rotates, the motor rotating shaft 100 is driven to rotate, the driving wheel 101 is driven to synchronously move, the driving wheel 101 moves to drive the driven wheel fixing piece 104 sleeved with the driving wheel 101 to move, the driven wheel 102 fixedly connected with the driven wheel fixing piece 104 is driven to move, and the driven wheel 102 drives the traction wire 107 connected with the driven wheel 102 to move, so that the linear reciprocating circular movement of the traction wire 107 is realized.

In the embodiment of the invention, two groups of driving modules, two groups of transmission modules and two groups of heat dissipation modules are arranged in a bilateral symmetry manner, so that the power control of the exoskeleton in the left direction and the right direction is realized. In the embodiment of the invention, a plurality of groups of driving modules, a plurality of groups of transmission modules and a plurality of groups of heat dissipation modules can be arranged in bilateral symmetry, so that the power control of the exoskeleton in multiple directions is realized.

Referring to fig. 8, a schematic diagram of a housing structure of the driving device according to the present invention is shown, and the driving device further includes a housing 110, and the driving module is disposed in the housing 110.

The power module 200 is electrically connected to the power board 15 to provide power for the whole device.

Referring to fig. 9, which is a schematic diagram illustrating a power module installation structure of the driving device of the present invention, and fig. 10, which is a schematic diagram illustrating an exploded structure of a battery module of the driving device of the present invention, the power module 200 includes a battery cell 201 and a battery case 202, and the battery cell 201 is disposed in the battery case 202.

The power module 200 may be built in the housing 110 or may be externally fixed to the housing 110.

Referring to fig. 9 and 13, in an embodiment of the present invention, a battery compartment 203 with an upper opening is provided on the housing 110, a bottom spring 207 is provided at the bottom of the battery compartment 203, a battery module 200 is detachably installed in the battery compartment 203, and the battery module 200 is electrically connected to the power board 15 by being placed in the battery compartment 203 with the upper opening.

In the embodiment of the invention, the battery cells are arranged as lithium batteries, and the battery cells in the lithium batteries are transversely arranged in an optimal mode designed according to the minimum space of the appearance.

Please refer to fig. 11 for a schematic diagram of a cross-sectional structure of a battery module in the driving device according to the embodiment of the present invention and fig. 12 for a schematic diagram of a partial cross-sectional structure of the driving device according to the embodiment of the present invention, in the embodiment of the present invention, a battery lock 204 is disposed on a battery module 200, and the battery lock 204 is fixed on a built-in spring piece 205 of the battery module; the battery compartment 203 is provided with the locking groove 210, the battery module 200 and the battery compartment 203 are connected in a clamping connection mode by matching the battery lock 204 with the locking groove 210, and when the battery module 200 and the battery compartment 203 are installed, the battery lock 204 can automatically spring into the locking groove 210 reserved in the battery compartment 203, so that the clamping locking and fixing effects of the battery module 200 and the battery compartment 203 are realized.

Referring to fig. 12, in the embodiment of the invention, a battery unlocking button 211 is disposed on the housing 110 corresponding to the locking slot 210.

By manually pressing the battery unlocking button 211 on the housing 110, the battery lock 204 on the battery module 200 is pushed away from the lock groove 210, and at the same time, the battery module 200 is integrally pushed away from the battery compartment 203 automatically by the elastic force of the bottom spring 207. This structural arrangement facilitates the mounting use and removal of the battery module 200.

Referring to fig. 13 for another cross-sectional structure of the driving device according to the embodiment of the present invention and fig. 14 for a partial structure of the bottom spring in fig. 13, in the embodiment of the present invention, one end of the bottom spring 207 is fixed under the battery compartment 203, and a spring housing 208 is disposed outside the other end, the upper portion of the housing is provided with a top-sealed column shape, an opening 209 is disposed at the bottom of the battery compartment 203 and is sleeved with the top column of the spring housing, and a large diameter structure with a diameter larger than that of the opening 209 is disposed at the bottom of the housing 208, so that the bottom spring 207 is sleeved at the bottom of the battery compartment by the spring housing 208, and the appearance is not affected. And the fixed position of the bottom spring 207 is set to be that when the large-diameter structure of the spring housing 208 is propped up to the bottom, the upper cylindrical top of the spring housing 208 is just flush with the bottom of the battery compartment 203, so that the spring housing 208 is ensured not to be ejected out of the opening 209 by misoperation, and the use is convenient.

Referring to fig. 2, fig. 4 and fig. 5, which are schematic diagrams showing the back of the driving device structure of the wearable exoskeleton of the present invention, in the embodiment of the present invention, the heat dissipation module further includes a heat dissipation fan 5 and a heat conducting fin 8, the heat dissipation fan 5 is connected to the heat dissipation device 2, one end of the heat dissipation device 2 is connected to the motor 1, the other end of the heat dissipation device 2 is further connected to the upper bracket 6, the upper bracket 6 provides support for the heat dissipation device 2, and realizes stability of the heat dissipation device 2 during operation; the heat conducting fin 8 is arranged between the driving plate 11 and the radiator 2, namely, the driving plate 11 is connected with the radiator 2 through the heat conducting fin 8, and the other end of the driving plate 11 is connected with the upper bracket 6. The heat conducting fin 8 is pressed and fixed by the locking pressure between the radiator 2 and the driving plate 11 and the upper bracket 6.

As shown in fig. 5, in the embodiment of the present invention, the radiator 2 is fixed on the motor 1 by the first radiator fixing screw 9, so as to achieve the close fitting between the radiator 2 and the motor 1, so as to achieve the best heat dissipation effect. In the embodiment of the present invention, as shown in fig. 6, the radiator 2 is further fixed to the upper bracket 6 by a second radiator fixing screw 19.

Through setting up the advantage of conducting strip 8 in radiating module, because driving plate 11 can produce great heat at work, conducting strip 8 will be with the heat conduction that driving plate 11 during operation produced to radiator 2 on, realize supplementary heat dissipation function, avoided driving plate 11 during operation overheated, maintained its during operation temperature steady in a reasonable range, guaranteed driving plate 11's steady operation. The heat conductive sheet 8 described in the embodiment of the present invention is specifically configured as a heat conductive silicone sheet.

Referring to fig. 2, the heat dissipation fan 5 is connected to the heat dissipation device 2 through a lower bracket 7, which is beneficial to stabilizing the stability of the heat dissipation device 2 and the heat dissipation fan 5 in the present invention. The heat dissipation fan 5 has the advantages that air convection can be utilized, heat exchange is carried out quickly, and the problem that generated heat cannot be discharged quickly due to the fact that a plurality of heat sources are arranged in the sealed cavity is solved.

Referring to fig. 7, in the embodiment of the invention, the cooling fan 5 is locked and fixed with the radiator 2 and the lower bracket 7 by the fan fixing screw 14.

Referring to fig. 8, in another embodiment of the present invention, the heat dissipation module further includes a heat dissipation hole 22, and the heat dissipation hole 22 is disposed at the bottom of the housing 110, so that heat in the cavity of the present invention can be timely discharged out of the device of the present invention through the heat dissipation hole 22, especially when the heat dissipation fan 5 works, the heat can be rapidly discharged. The heat dissipation holes 22 are provided in 1 or more.

The advantage of the heat dissipation holes 22 formed in the bottom of the housing 110 is that: can effectively play the roles of dust prevention, water prevention and foreign matter entering prevention.

The working principle of the heat dissipation module is as follows: the heat generated during the operation of the motor 1 is directly transferred to the radiator 2, the heat is transferred to the radiator 2 through the heat conducting fin 8 during the operation of the driving plate 11, and the heat in the heat conducting fin 2 and the heat in the space in the shell 110 are transferred to the heat radiating holes 22 through the heat conducting air channel during the operation of the heat radiating fan 5 to be discharged out of the device.

Referring to fig. 20, which is a schematic cross-sectional view of a driving device with a light guide column according to an embodiment of the present invention, fig. 21 is a partially enlarged view of the light guide column in fig. 20, wherein fig. 21 is a schematic enlarged view of a structure of the light guide column in fig. 20, and a light source indicator 300 is further provided for identifying the working state of the present invention, in order to avoid the problem of uneven backlight of a device, the light guide column 301 is provided with light guide column explosion-proof points 302, and the light guide column explosion-proof points 302 in the embodiment of the present invention are provided with light scattering teeth, and refract strong light sources to a dark area of the light guide column through a toothed inclined plane, thereby solving the problem of uneven backlight and realizing the uniform backlight effect of the light guide column.

The cross section of the driving wheel 101 is arranged to be non-circular, in particular to a structure of a multi-arc triangle, a tri-arc triangle or a Lai triangle with the vertex being led into a round angle, so that the driving wheel 101 can generate higher torque, reduce the abrasion of the driving wheel 101 and materials sleeved on the driving wheel, provide high torque support, and better transmit transmission power to all parts sleeved on the driving wheel, thereby having ingenious structural design, improving the service life and the transmission performance; the arrangement of the bearing 103 and the driven wheel fixing piece 104 increases the axial stress bearable by the turntable, protects the bearing 103 in the driving device, prolongs the service life of the motor 1, simultaneously makes the power transmission from the driving wheel 101 to the driven wheel 102 softer and not harder, has better safety, and has the advantages of compactness, simplicity and low transmission noise.

In this specification, the invention has been described with reference to specific embodiments thereof, but it will be apparent that various modifications and alterations can be made without departing from the spirit and scope of the invention. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.

Claims

1. The driving device of the wearable exoskeleton is characterized by comprising a driving module and a transmission module, wherein the driving module comprises a motor, the transmission module comprises a motor rotating shaft, a driving wheel and a driven wheel, the driving wheel is connected with the motor through the motor rotating shaft, the driven wheel is connected with the driving wheel, and the section of the driving wheel is non-circular.

2. The driving device for a wearable exoskeleton of claim 1 wherein the driving wheel is multi-arc shaped in cross section.

3. The driving device for a wearable exoskeleton of claim 2 wherein the driving wheel has a three-arc-shaped cross section.

4. The driving device for a wearable exoskeleton of claim 1 wherein the driving wheel has a cross section of a leo triangle with rounded vertices.

5. The wearable exoskeleton driving device according to any one of claims 1 to 4, wherein the driven wheel is configured as a pulley structure centering on the driving wheel.

6. The driving device for the wearable exoskeleton of claim 5, wherein the transmission module further comprises a bearing, the driving wheel is connected with the driven wheel through the bearing, the inner ring of the driven wheel is sleeved with the outer ring of the bearing, and the inner ring of the bearing is sleeved with the outer ring of the driving wheel.

7. The driving device of the wearable exoskeleton of claim 6, wherein the transmission module further comprises a driven wheel fixing member, the driven wheel fixing member is sleeved on the outer ring of the driving wheel, the inner ring shape of the driven wheel fixing member is engaged with the outer ring shape of the driving wheel in a matched and engaged manner, and the driven wheel is connected with the driven wheel fixing member.

8. The wearable exoskeleton driving device of claim 7 wherein the transmission module further comprises a traction wire, the traction wire being connected to the driven wheel; the traction wire is provided as a bowden wire.

9. The driving device for the wearable exoskeleton of claim 8, wherein one end of the bowden cable is fixedly installed in a preset fixing groove of the driven wheel, and the bowden cable is fixed by a set pressing piece and a screw.

10. The driving device of the wearable exoskeleton of claim 9, wherein the driving wheel is fixedly connected with the motor shaft through a driving wheel fixing screw; the driven wheel is fixedly connected with the driven wheel fixing piece through a driven wheel fixing piece fixing screw.