CN219655180U - Transmission device - Google Patents

Abstract

The utility model provides a transmission device, in which a transmission surface of a third roller contacts a transmission member, and a position adjusting mechanism adjusts the position of the third roller relative to the transmission member so that the transmission member can be properly tensioned thereat; meanwhile, at the two sides of the third roller, the transmission surfaces of the first roller and the second roller are in contact with opposite sides of the transmission piece relative to the transmission surface of the third roller, the extending direction of the transmission piece is effectively limited, the tensioning action of the third roller on the transmission piece is prevented from changing the extending direction of the transmission piece, and adverse effects on normal transmission are avoided. By using the transmission device, the transmission part can be tensioned under the condition of keeping the extending direction of the transmission part, so that the transmission part is prevented from loosening in the long-term use process, and the transmission precision is prevented from being influenced.

Description

Transmission device

Technical Field

The utility model relates to the field of medical instruments, in particular to a transmission device.

Background

In the prior art, the caster control of the medical apparatus and instruments is usually controlled by driving a wire through a driving wheel, for example, the document of Chinese patent grant publication No. CN 108609044B discloses a scheme for realizing driving control by means of a driving member: as shown in fig. 1, the transmission mechanism is specifically characterized in that a driving wheel is respectively arranged on a power source and a part to be transmitted, one driving wheel is a first driving wheel 2', and is coaxially connected with the power source, the other driving wheel is a second driving wheel 6', and is coaxially connected with the part to be transmitted, two driving wires 1' are respectively arranged between the first driving wheel 2' and the second driving wheel 6', the tail ends of the driving wires 1' are respectively clamped and fixed on a fixing mechanism 3' of the first driving wheel 2' and a fixing mechanism 3' of the second driving wheel 6', and further the purpose of driving the second driving wheel 6' to synchronously rotate is achieved by respectively pulling the two driving wires 1' at the upper end and the lower end through rotation of the first driving wheel 2 '.

However, the transmission wire 1' in the transmission device is usually a flexible member, such as a transmission wire, a rope or a belt, and the like, and is deformed and loosened during long-term use, thereby affecting the transmission accuracy of the transmission device.

Disclosure of Invention

The utility model aims to overcome the defect that a flexible transmission piece in the prior art can loosen in a long-term use process to influence transmission precision.

The utility model solves the technical problems by the following technical scheme:

the utility model provides a transmission, its includes first drive wheel, second drive wheel and driving medium, the driving medium cover is between first drive wheel and the second drive wheel, transmission still includes tensioning structure, tensioning structure includes:

the first roller and the second roller are arranged between the first driving wheel and the second driving wheel along the extending direction of the driving piece, and the driving surfaces of the first roller and the second roller are in contact with the same side of the driving piece;

the third roller is arranged between the first roller and the second roller, the transmission surface of the third roller is opposite to the transmission surface of the first roller and the transmission surface of the second roller and is in contact with the opposite side of the transmission part, the third roller is rotatably connected to the position adjusting mechanism, and the position adjusting mechanism can adjust the position of the third roller along the direction different from the extending direction of the transmission part.

In the technical scheme, the transmission surface of the third roller contacts the transmission member, and the position adjusting mechanism adjusts the position of the third roller relative to the transmission member, so that the transmission member can be properly tensioned at the position; meanwhile, at the two sides of the third roller, the transmission surfaces of the first roller and the second roller are in contact with opposite sides of the transmission piece relative to the transmission surface of the third roller, the extending direction of the transmission piece is effectively limited, the tensioning action of the third roller on the transmission piece is prevented from changing the transmission path of the transmission piece, and adverse effects on normal transmission are avoided. By using the transmission device, the transmission part can be tensioned under the condition of keeping the extending direction of the transmission part, so that the transmission part is prevented from loosening in the long-term use process, and the transmission precision is prevented from being influenced.

Preferably, the transmission device further comprises a base, the tensioning structure further comprises a first bracket and a second bracket, the first bracket and the second bracket are both fixed on the base, the first roller is rotatably connected to the first bracket, and the second roller is rotatably connected to the second bracket.

In this technical scheme, still include the base through setting up transmission to, set up tensioning structure to still including first support, second support, first support the second support is all fixed on the base, first gyro wheel swivelling joint is in on the first support, second gyro wheel swivelling joint is in on the second support to reach through relative succinct structure and set up fixed purpose respectively with first gyro wheel, second gyro wheel, simultaneously, fixed first gyro wheel and second gyro wheel through different supports, make things convenient for the part maintenance and change.

Preferably, the transmission device further comprises a base, the position adjusting mechanism comprises a third bracket and an adjusting part, the third roller is rotatably connected to the third bracket, the third bracket is movably connected to the base along the adjusting direction of the third roller, and the adjusting part can adjust the position of the third bracket.

In this technical scheme, through setting up third gyro wheel swivelling joint on swing joint in the regulation direction swing joint along the third gyro wheel on the third support of base, and be equipped with the regulation portion of regulation third support position, compare other structure setting schemes, can reach the purpose of the regulation direction adjustment of third gyro wheel with succinct structure with the third gyro wheel.

Preferably, the adjusting part is an adjusting screw, the adjusting screw is connected to the third bracket along the adjusting direction of the third roller in a threaded manner, and the tail end of the adjusting screw abuts against the base.

In this technical scheme, through setting up adjusting part as adjusting screw, adjusting screw follows the direction of adjustment threaded connection of third gyro wheel in the third support, and adjusting screw's end supports on the base, and rotatory adjusting screw this moment, the third support can be for the base along the direction of adjustment of third gyro wheel back and forth movement, compares other structure setting schemes, can reach the purpose of adjusting the direction of adjustment of third gyro wheel with succinct structure with the third support. Meanwhile, the self-locking principle that the threads of the adjusting screw can only move through rotating the relative screw holes is utilized, so that the third bracket can be prevented from accidentally moving relative to the base after the position is adjusted, the reliability of the transmission device is improved, and the purpose of preventing the transmission device from loosening is achieved.

Preferably, the third bracket is provided with a groove extending along the adjusting direction of the third roller, the third bracket is fixed on the base through a mounting screw, and the mounting screw is arranged in the groove of the third bracket in a penetrating manner.

In this technical scheme, through set up the groove that extends along the regulation direction of third gyro wheel on the third support, mounting screw wears to locate the inslot of third support, moves the suitable position around the regulation direction of third gyro wheel with the third support for the base this moment, screws up mounting screw again, compares other structure setting schemes, can reach the purpose of being fixed in the base with succinct structure with the third support.

Preferably, the transmission member is divided into a first part and a second part by the first transmission wheel and the second transmission wheel; the transmission device comprises two sets of tensioning structures, and the two sets of tensioning structures are respectively arranged on the first part and the second part of the transmission piece.

In the technical scheme, the transmission device comprises two sets of tensioning structures, the two sets of tensioning structures are respectively arranged on the first part and the second part of the transmission piece, which are divided by the first transmission wheel and the second transmission wheel, so that uneven stress during tensioning of the transmission piece can be avoided, sliding occurs relative to the transmission surfaces of the first transmission wheel and the second transmission wheel, and the transmission precision of the transmission device is affected.

Preferably, the tensioning structure further comprises a first bracket and a second bracket, and the first rollers of the two sets of tensioning structures are simultaneously and rotatably connected to the same first bracket; the second rollers of the two sets of tensioning structures are simultaneously and rotatably connected to the same second bracket.

In this technical scheme, through with the first gyro wheel simultaneous swivelling joint of two sets of tensioning texture on same first support, the second gyro wheel simultaneous swivelling joint of two sets of tensioning texture is on same second support, compares other structure setting schemes and can reduce support quantity, arranges two sets of tensioning texture more succinctly on same driving medium.

Preferably, the first roller also acts as a reversing wheel.

In this technical scheme, through also regard as the switching-over wheel with first gyro wheel, can make this tensioning structure when tensioning the driving medium, compare other structure setting schemes, can be with succinct structural adaptation need take place the transmission of switching-over between first drive wheel and second drive wheel, need not additionally set up other structures.

Preferably, the first bracket covers the outer side of the first roller, a first hollowed-out part is arranged on the first bracket, and the first hollowed-out part exposes out of a part of the transmission surface of the first roller, which is contacted with the transmission piece; and/or the third support covers the outer side of the third roller, the third support is provided with a second hollowed-out part, and the second hollowed-out part exposes the part of the transmission surface of the third roller, which is contacted with the transmission piece.

In this technical scheme, through setting up first support to the outside of covering first gyro wheel, protect first gyro wheel, set up first fretwork portion on first support, first fretwork portion exposes the driving surface of first gyro wheel and the part that the driving medium contacted, and the maintenance personal of being convenient for overhauls first gyro wheel through first fretwork portion.

Simultaneously, set up the outside of third gyro wheel as the cover with the third support, protect the third gyro wheel, set up third fretwork portion on the third support, third fretwork portion exposes the transmission face of third gyro wheel and the part that the driving medium contacted, can be convenient for protect the third gyro wheel from outside possible impact, be convenient for the maintenance personal overhauls the third gyro wheel through the second fretwork portion simultaneously.

Preferably, the transmission surfaces of the first roller, the second roller and the third roller are V-shaped surfaces, and the V-shaped surfaces are matched with the section shape of the transmission piece.

In this technical scheme, through all setting the driving surface of first gyro wheel, second gyro wheel, third gyro wheel to the V-arrangement face, the cross-section shape assorted of V-arrangement face and driving medium can make the driving medium be difficult for sliding on the driving surface of first gyro wheel, second gyro wheel, third gyro wheel, promotes transmission's stability.

The utility model has the positive progress effects that:

by using the transmission device, the transmission part can be tensioned under the condition of keeping the extending direction of the transmission part, so that the transmission part is prevented from loosening in the long-term use process, and the transmission precision is prevented from being influenced.

Drawings

Fig. 1 is a schematic diagram of a prior art transmission.

Fig. 2 is a schematic structural diagram of a transmission device in embodiment 1 of the present utility model.

Fig. 3 is a schematic structural diagram of a transmission device in embodiment 2 of the present utility model.

Fig. 4 is a schematic diagram showing a specific structure of a tensioning structure according to embodiment 2 of the present utility model.

Reference numerals illustrate:

the prior art comprises the following steps:

drive wire 1'

A first driving wheel 2'

Fixing mechanism 3'

A second driving wheel 6'

The utility model comprises the following steps:

transmission wire 1

First portion 11

Second portion 12

Tensioning arrangement 2

First roller 21

Second roller 22

Third roller 23

Position adjusting mechanism 24 for adjusting direction a

Third support 241

Groove 2411

Mounting screw 2412

Second hollowed-out portion 2413

Adjusting screw 242

First support 25

First hollowed-out part 251

Second support 26

Base 3

First driving wheel 4

Second driving wheel 5

Detailed Description

The present utility model will now be described more fully hereinafter with reference to the accompanying drawings, in which two preferred embodiments are shown.

Example 1

As shown in fig. 2, the present embodiment provides a transmission device, which includes a first transmission wheel 4, a second transmission wheel 5, and a transmission wire 1, wherein the transmission wire 1 is sleeved between the first transmission wheel 4 and the second transmission wheel 5, the transmission device further includes a tensioning structure 2 for adjusting the tightness degree of the transmission wire 1 between the first transmission wheel 4 and the second transmission wheel 5, and the tensioning structure 2 specifically includes a first roller 21, a second roller 22, a third roller 23, and a position adjusting mechanism 24.

Wherein the first roller 21 and the second roller 22 are arranged between the first driving wheel 4 and the second driving wheel 5 along the extending direction of the driving wire 1 and are positioned on the same side of the driving wire 1, the driving surfaces of the first roller 21 and the second roller 22 are both contacted with the driving wire 1, the third roller 23 and the position adjusting mechanism 24 are arranged at the position between the first roller 21 and the second roller 22, the third roller 23 is positioned opposite to the driving wire 1 relative to the first roller 21 and the second roller 22, the driving surface of the third roller 23 is also contacted with the driving wire, the third roller 23 is arranged on the position adjusting mechanism 24, and the position adjusting mechanism 24 can adjust the positions of the third roller 23 and the driving wire 1 along the adjusting direction A perpendicular to the extending direction of the driving wire 1 so as to realize the adjustment of the tightness of the driving wire 1 by pushing and abutting of the third roller 23 on the driving wire 1. Of course, in other embodiments, the position adjusting mechanism 24 may also drive the third roller 23 to move relative to the driving wire 1 along other directions, and the purpose of adjusting the tightness can be achieved only by being different from the extending direction of the driving wire 1. In addition, the specific structural arrangement scheme of the position adjusting mechanism 24 driving the third roller 23 to displace relative to the driving wire 1 may be implemented by using a scheme existing in the prior art, for example: the specific structure that the position adjusting mechanism 24 in this embodiment can adopt is not described here again, and is driven by a linear motor or by an air cylinder or the like.

In the present embodiment, the transmission surface of the third roller 23 contacts the transmission wire 1, and the position of the third roller 23 relative to the transmission wire 1 is adjusted by the position adjusting mechanism 24, so that the transmission wire 1 can be properly tensioned thereat; meanwhile, on two sides of the third roller 23, the transmission surfaces of the first roller 21 and the second roller 22 are in opposite side contact with the transmission wire 1 relative to the transmission surface of the third roller 23, so that the transmission wire 1 is effectively limited, the transmission path of the transmission wire 1 is prevented from being changed due to tensioning action of the third roller 23 on the transmission wire 1, and adverse effects on normal transmission are avoided. Thus, by using the transmission device, the transmission wire 1 can be tensioned while the transmission path of the transmission wire 1 is maintained, so that the transmission wire 1 is prevented from loosening in the long-term use process, and the transmission precision is prevented from being influenced.

In this embodiment, the structure for achieving synchronous transmission between the first transmission wheel 4 and the second transmission wheel 5 is the transmission wire 1, however, in other embodiments, synchronous transmission can be achieved by providing other transmission members between the first transmission wheel 4 and the second transmission wheel 5, such as a transmission rope, a transmission belt, and the like. In the case of transmissions by means of these transmission members, tensioning means 2 can likewise be provided to adjust the degree of tensioning of the transmission members while ensuring their transmission path.

Example 2

The present embodiment provides a transmission device, and the specific structure of the transmission device is different on the basis of embodiment 1.

As shown in particular in fig. 3-4, in this embodiment the transmission wire 1 is divided into a first part 11 and a second part 12 by a first transmission wheel 4 and a second transmission wheel 5. The transmission comprises two sets of tensioning arrangements 2, which sets of tensioning arrangements 2 are arranged on the first part 11 and the second part 12, respectively, for tensioning different positions of the transmission wire 1. By arranging two sets of tensioning structures 2 to tension different positions of the transmission wire 1, the problem that the transmission accuracy of a transmission device is affected due to the fact that the transmission surfaces of the first transmission wheel 4 and the second transmission wheel 5 slide due to uneven stress during tensioning of the transmission wire 1 can be effectively avoided.

As shown in fig. 4, the transmission in this embodiment comprises a base 3 for receiving the tensioning structure 2. Meanwhile, the tensioning structure 2 further comprises a first bracket 25 and a second bracket 26, the first bracket 25 and the second bracket 26 are both fixed on the base 3, the first roller 21 is rotatably connected to the first bracket 25, and the second roller 22 is rotatably connected to the second bracket 26.

Like this, through setting up base 3, set up tensioning texture 2 to still including first support 25, second support 26, first support 25, second support 26 are all fixed on base 3, first gyro wheel 21 swivelling joint is on first support 25, second gyro wheel 22 swivelling joint is on second support 26 to reach through relative succinct structure and set up fixed purpose respectively with first gyro wheel 21, second gyro wheel 22, simultaneously, fixed first gyro wheel 21 and second gyro wheel 22 through different supports, make things convenient for the part maintenance and change.

In this embodiment, the position adjusting mechanism 24 specifically includes a third bracket 241 for mounting the third roller 23 and an adjusting portion mounted on the base 3, where the adjusting portion is used for adjusting the position of the third bracket 241 on the base 3, so as to achieve the purpose of driving the third roller 23 to tension the transmission wire 1.

In this way, the third roller 23 is connected to the third bracket 241 arranged on the base 3, and the position of the third bracket 241 is adjusted by the additionally arranged adjusting part, so that the purpose of adjusting the position of the third roller 23 is achieved by a simpler structure compared with other structural arrangement schemes.

As shown in fig. 4, the adjusting part in this embodiment is specifically configured by an adjusting screw 242 mounted on a third bracket 241, the adjusting screw 242 is screwed on an end portion of the third bracket 241 and is disposed along an adjusting direction a of the third roller 23, a distal end of the adjusting screw 242 abuts against the base 3, the adjusting screw 242 is displaced relative to the third bracket 241 along the adjusting direction a of the third roller 23 by screwing the adjusting screw 242, the distal end of the adjusting screw 242 abuts against a cross beam on the base 3, and the generated reaction force drives the third bracket 241 and the third roller 23 to move toward the transmission wire 1, so as to further tension the transmission wire 1.

Thus, by setting the adjusting portion as the adjusting screw 242, the adjusting screw 242 is screwed to the third bracket 241 along the adjusting direction a of the third roller 23, the end of the adjusting screw 242 abuts against the base 3, at this time, the adjusting screw 242 is rotated, and the third bracket 241 can move back and forth relative to the base 3, so as to achieve the purpose of adjusting the position of the third roller 23 of the third bracket 241 with a simple structure. Meanwhile, by utilizing the self-locking principle that threads can only move through rotating relative screw holes, the third bracket 241 can be effectively prevented from accidentally moving relative to the base 3 after the position is adjusted, the reliability of the transmission device is improved, and the aim of preventing the transmission device from loosening is fulfilled. Of course, in other embodiments, the adjusting portion may be configured to achieve the same purpose of adjusting the positions of the third bracket 241 and the third roller 23, for example: the third bracket 241 and the third roller 23 are driven to adjust positions by means of springs, elastic ropes and the like.

In this embodiment, the third bracket 241 is provided with a groove 2411 extending along the adjustment direction a of the third roller 23, the third bracket 241 is fixed to the base 3 by a mounting screw 2412, and the mounting screw 2412 is inserted into the groove 2411 of the third bracket 241.

In this way, by providing the groove 2411 extending along the adjustment direction a of the third roller 23 on the third bracket 241, the mounting screw 2412 is inserted into the groove 2411 of the third bracket 241, and at this time, the third bracket 241 is moved to a suitable position back and forth relative to the base 3, and then the mounting screw 2412 is tightened, so that the purpose of fixing the third bracket 241 to the base 3 can be achieved with a simple structure compared with other structural arrangements. Of course, in other embodiments, other structures may be provided on the third bracket 241, which may achieve the purpose of fixing the third bracket 241 to the base 3 with a simple structure.

In this embodiment, as two sets of tensioning structures 2 are provided to tension different positions of the transmission wire 1, in order to further simplify the structure, the first rollers 21 of the two sets of tensioning structures 2 are simultaneously mounted on the same first bracket 25, and the second rollers 22 of the two sets of tensioning structures 2 are simultaneously mounted on the same second bracket 26, and the first rollers 21 and the second rollers 22 on the different tensioning structures 2 are fixed by using a single first bracket 25 and a single second bracket 26, so that the number of parts is further simplified, and the maintenance difficulty is reduced.

In this embodiment, as can be seen from fig. 4, the transmission path of the transmission wire 1 at the first roller 21 is changed, and the first roller 21 also serves as a reversing wheel. By using the first roller 21 as a reversing wheel, no additional structure is needed to further reduce the number of parts.

In addition, as shown in fig. 4, in the present embodiment, the first bracket 25 covers the outer side of the first roller 21, the first bracket 25 has a first hollowed portion 251, and the first hollowed portion 251 exposes a portion of the transmission surface of the first roller 21 that contacts the transmission wire 1; meanwhile, the third support 241 covers the outer side of the second roller 22, the third support 241 is provided with a second hollowed portion 2413, and the second hollowed portion 2413 exposes a portion of the transmission surface of the second roller 22, where the transmission wire 1 contacts.

Thus, by disposing the first bracket 25 so as to cover the outer side of the first roller 21, a first hollowed portion 251 is disposed on the first bracket 25, and the first hollowed portion 251 exposes a portion of the transmission surface of the first roller 21 that contacts the transmission wire 1; and, set up the third support 241 to cover the outside of third gyro wheel 23, set up second fretwork portion 2413 on third support 241, the portion that the transmission face of third gyro wheel 23 and transmission silk 1 contacted is exposed to second fretwork portion 2413, can be convenient for protect first gyro wheel 21 and third gyro wheel 23 from outside possible impact, be convenient for the maintenance personal simultaneously overhauls first gyro wheel 21, second gyro wheel 22 respectively through first fretwork portion 251, second fretwork portion 2413. Of course, in other embodiments, the first bracket 25 and the third bracket 241 may be further configured to protect the first roller 21 and the third roller 23 from possible external impact, and simultaneously facilitate maintenance personnel to inspect the structures of the first roller 21 and the third roller 23 through the first hollow portion 251 and the second hollow portion 2413, respectively.

In this embodiment, the transmission surfaces of the first roller 21, the second roller 22 and the third roller 23 are V-shaped surfaces, and the V-shaped surfaces are matched with the cross-sectional shape of the transmission wire 1, so as to improve the transmission effect and the stability of the transmission device. Of course, in other embodiments, the driving surfaces of the first roller 21, the second roller 22 and the third roller 23 may be configured in other shapes for improving the stability of the driving device, for example, a U-shaped groove is provided on the driving surface, etc.

While specific embodiments of the utility model have been described above, it will be appreciated by those skilled in the art that this is by way of example only, and the scope of the utility model is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the principles and spirit of the utility model, but such changes and modifications fall within the scope of the utility model.

Claims (10)

1. The utility model provides a transmission, its includes first drive wheel, second drive wheel and driving medium, the driving medium cover is between first drive wheel and the second drive wheel, its characterized in that, transmission still includes tensioning structure, tensioning structure includes:

the first roller and the second roller are arranged between the first driving wheel and the second driving wheel along the extending direction of the driving piece, and the driving surfaces of the first roller and the second roller are in contact with the same side of the driving piece;

the third roller is arranged between the first roller and the second roller, the transmission surface of the third roller is opposite to the transmission surface of the first roller and the transmission surface of the second roller and is in contact with the opposite side of the transmission part, the third roller is rotatably connected to the position adjusting mechanism, and the position adjusting mechanism can adjust the position of the third roller along the direction different from the extending direction of the transmission part.

2. The transmission of claim 1, further comprising a base, wherein the tensioning structure further comprises a first bracket and a second bracket, wherein the first bracket and the second bracket are both fixed to the base, wherein the first roller is rotatably coupled to the first bracket, and wherein the second roller is rotatably coupled to the second bracket.

3. The transmission of claim 1, further comprising a base, wherein the position adjustment mechanism comprises a third bracket and an adjustment portion, the third roller is rotatably connected to the third bracket, the third bracket is movably connected to the base along an adjustment direction of the third roller, and the adjustment portion is capable of adjusting a position of the third bracket.

4. A transmission according to claim 3, wherein the adjustment portion is an adjustment screw threadedly coupled to the third bracket in the adjustment direction of the third roller, and the end of the adjustment screw abuts the base.

5. A transmission according to claim 3, wherein the third bracket is provided with a slot extending in the adjustment direction of the third roller, the third bracket being secured to the base by a mounting screw, the mounting screw being disposed through the slot of the third bracket.

6. A transmission according to claim 1, wherein the transmission member is divided into a first portion and a second portion by the first and second transmission wheels; the transmission device comprises two sets of tensioning structures, and the two sets of tensioning structures are respectively arranged on the first part and the second part of the transmission piece.

7. The transmission of claim 6, wherein said tensioning structure further comprises a first bracket and a second bracket, said first rollers of both sets of said tensioning structures being simultaneously rotatably connected to the same first bracket; the second rollers of the two sets of tensioning structures are simultaneously and rotatably connected to the same second bracket.

8. The transmission of claim 1, wherein the first roller also acts as a reversing wheel.

9. The transmission of claim 8, further comprising a base, wherein the tensioning mechanism further comprises a first bracket, the position adjustment mechanism comprises a third bracket and an adjustment portion, the first bracket is fixed on the base, the first roller is rotatably connected to the first bracket, the third roller is rotatably connected to the third bracket, the third bracket is movably connected to the base along an adjustment direction of the third roller, and the adjustment portion is capable of adjusting a position of the third bracket;

the first bracket covers the part of the transmission surface of the first roller, which is contacted with the transmission piece, and is provided with a first hollowed-out part which exposes the part of the transmission surface of the first roller, which is contacted with the transmission piece; and/or the number of the groups of groups,

the third support covers the transmission surface of the third roller and the contact part of the transmission piece, the third support is provided with a second hollowed-out part, and the second hollowed-out part exposes the transmission surface of the third roller and the contact part of the transmission piece.

10. The transmission of claim 1, wherein the transmission surfaces of the first roller, the second roller, and the third roller are V-shaped surfaces that match the cross-sectional shape of the transmission member.