Transmission

Abstract

The present invention relates to the technical field of transmission systems, particularly to transmissions, and includes a box-type transmission and a shift operating system, wherein the box-type transmission includes a housing, a main shaft, a counter shaft, a main shaft gear, a counter shaft gear, and a ratchet, and the shift operating system includes an elastic fork mechanism, a shift guide groove drum bar for moving and driving the elastic fork mechanism, a shift operating gear group for rotating the shift guide groove drum bar, and a shift control mechanism for rotating the shift operating gear group, the shift guide groove drum bar being rotatably mounted on the housing. The present invention employs a rotatable connection between the fork arm and the fork seat, which reduces friction, makes gear engagement and disengagement more flexible, extends the service life of the elastic member, and effectively avoids damage to the ratchet teeth due to tooth contact, sticking, or excessive pulling between the ratchet and the gear, thereby effectively extending the service life of the elastic member, the shift operating system, and the transmission.

Description

[Technical Field]

[0001] The present invention relates to the field of transmission systems, and more particularly to transmissions. [Background technology]

[0002] In a transmission transmission system, a shift operation system is required to achieve a transmission change mechanism between different gear pairs of the transmission. Most existing shift operation systems use a rigid shift fork, and when the fork drives the ratchet to engage with the gear, the ratchet teeth on the end face of the gear are likely to strongly butt against each other, causing tooth strike or sticking. When the ratchet disengages from the gear, the ratchet teeth are likely to be damaged by being forcibly pulled.

[0003] Chinese invention patent application publication number CN115195932A discloses a bicycle center shaft derailleur with load shifting, in which a resilient notch and a resilient piece are installed in the fork, and a shift operating mechanism is disclosed in which the resilient piece's repeated resilience is utilized to realize the resilience of the fork. During use of the fork structure, the resilient piece not only performs a reciprocating deformation function, but also needs to perform a certain connecting and supporting function, and the resilient piece is prone to early fatigue failure, still causing ratchet and gear teeth to clash or get stuck, and shortening the service life of the derailleur or the derailleur.

[0004] Due to the shortcomings of the above-mentioned existing shifting operation systems that adopt rigid forks and elastic forks, there is a need to provide a solution to overcome the above-mentioned technical problems. Summary of the Invention [Problem to be solved by the invention]

[0005] In response to the shortcomings of the prior art, the present invention provides a transmission in which the shift fork adopts a rotatable connection between the fork arm and the fork seat, which has low friction, is more flexible in-gear and out-gear, has a long service life for the elastic member, and can effectively prevent damage to the ratchet caused by ratchet and gear teeth contact, sticking, forceful pulling, etc. [Means for solving the problem]

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions.

[0007] The present invention provides a transmission including a box-type transmission and a shift operation system, wherein the box-type transmission includes a housing, a main shaft and a counter shaft mounted in parallel to the housing, at least one main shaft gear is mounted on the main shaft, a counter shaft gear is mounted on the counter shaft and meshes with the main shaft gear, a ratchet is slidably mounted on the main shaft and meshes with the main shaft gear, and / or a ratchet is mounted on the counter shaft and meshes with the counter shaft gear, and the ratchet is drivingly connected to the shift operation system, The shift operation system includes an elastic fork mechanism, a shift guide groove drum rod for moving and driving the elastic fork mechanism, a shift operation gear group for rotating and driving the shift guide groove drum rod, and a shift control mechanism for rotating and driving the shift operation gear group, and the shift guide groove drum rod is rotatably attached to a housing, The elastic fork mechanism includes a fork seat, a fork arm rotatably connected to the fork seat, and an elastic member for resetting and driving the fork arm, and when the fork arm swings relative to the fork seat, the elastic member drives and resets the fork arm; A shift guide groove is provided on the circumferential surface of the shift guide groove drum rod, a fork convex post is provided on the upper end of the fork seat, and the fork convex post is movably installed in the shift guide groove, and the lower end of the fork arm is movably connected to the ratchet.

[0008] Here, the box-type transmission further includes a chain wheel attached to a main shaft and cranks attached to both ends of the main shaft, A lower fork portion is provided on the fork arm, and a stripper is provided on the inner side of both ends of the lower fork portion, and the stripper is movably installed in the fork groove on the circumferential surface of the ratchet.

[0009] Here, two slide guide holes are installed in parallel on the upper part of the fork seat, and the fork seat is fitted onto two guide rods using the slide guide holes, and the two guide rods are attached to the housing.

[0010] Preferably, a mounting groove is provided at the bottom of the fork seat, a fork arm connecting part is provided at the fork arm, and the fork arm connecting part is mounted in the mounting groove by using a fork arm rotation axis; The elastic member is a torsion spring, the spring body of which is attached to the fork arm rotation shaft, and the output end head of the torsion spring clamps the fork arm connection portion and the fork seat.

[0011] Here, a storage groove is provided at the fork arm connection portion, the fork arm rotation shaft passes through the storage groove, the spring body of the torsion spring is attached to the storage groove, and the output end head extends out of the storage groove and then clamps the fork seat.

[0012] Here, the shift operation gear group is attached to a housing, and the shift operation gear group includes a shift operation driven gear attached to a shift guide groove drum rod and a shift operation drive gear meshing with the shift operation driven gear, and a return coil spring for resetting and driving the gear is installed on one side of the shift operation drive gear, one end of the return coil spring is connected to a gear wall of the shift operation drive gear, and the other end of the return coil spring is connected to a mounting shaft of the shift operation drive gear.

[0013] Here, the shift control mechanism includes a shift wire, a wire adjusting mechanism, and a wire controller, a wire mounting groove is provided in the shift operation drive gear, one end of the shift wire is fitted around the wire mounting groove, and the other end of the shift wire passes through the wire adjusting mechanism and then enters the wire controller.

[0014] Here, the wire adjustment mechanism includes a mounting seat installed on a transmission housing, an adjustment screw connected to the mounting seat, and a lock nut connected to the adjustment screw, a seat body screw hole is provided in the mounting seat, the seat body screw hole is connected to the inside of the transmission housing, the adjusting screw has a hollow structure, and an adjusting screw segment is provided in the adjusting screw; The adjusting screw segment is threaded into the seat body threaded hole, the lock nut is fitted onto the adjusting screw segment and threadedly engages with the adjusting screw segment, and the elastic fork mechanism, shift guide groove drum rod, and shift operation gear group are all installed within the transmission housing.

[0015] Here, the adjusting screw further includes a screw head portion connected to the adjusting screw segment, and the mounting seat and the transmission housing are integrally formed.

[0016] Here, the wire adjusting mechanism further includes a wire pipe, and a pipe recess is provided at one end of the screw head portion away from the adjusting screw segment, and one end of the wire pipe is attached to the pipe recess. [Effects of the Invention]

[0017] The beneficial effects of the present invention are as follows:

[0018] (1) The present invention employs a rotatable connection between the fork arm and the fork seat, and when the fork arm swings relative to the fork seat, the elastic member always drives the fork arm to reset, providing elasticity to the fork structure. The elastic fork mechanism acts to release the force when driving the ratchet into gear and meshing with the main shaft gear or countershaft gear, thereby preventing the ratchet teeth from hitting or getting stuck on the end face of the main shaft gear or countershaft gear, and preventing damage to the ratchet teeth caused by forcibly pulling the ratchet when the ratchet is disengaged from the main shaft gear or countershaft gear.

[0019] (2) The present invention adopts a rotatable connection between the fork arm and the fork seat, which reduces friction when the fork arm swings, making the engagement and disengagement of the ratchet and the main shaft gear or countershaft gear more flexible. When the fork arm swings a small angle relative to the fork seat 1, a large displacement of the ratchet can be obtained. Compared to the displacement adopted in existing rigid forks and some elastic forks, this not only causes less damage but also has a longer service life. It reduces the elastic deformation of the elastic member, prevents the elastic member from prematurely failing, and effectively extends the service life of the elastic member, the elastic fork mechanism, and the transmission. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a schematic diagram of the three-dimensional structure of the present invention. [Figure 2] FIG. 10 is a schematic diagram of the three-dimensional structure of the present invention at another viewing angle. [Figure 3] FIG. 2 is a schematic diagram of the three-dimensional structure of the present invention after the housing is hidden. [Figure 4] FIG. 10 is a schematic diagram of the three-dimensional structure of the present invention at a different viewing angle after the housing is hidden. [Figure 5] FIG. 10 is a structural schematic diagram of the present invention after the housing is hidden, showing another viewing angle. [Figure 6] 1 is a schematic diagram of the three-dimensional structure of a shift operation system according to the present invention; [Figure 7]FIG. 2 is a schematic diagram of the three-dimensional structure of the shift operation system according to the present invention at another viewing angle. [Figure 8] 1 is a schematic diagram of a three-dimensional structure of an elastic fork mechanism according to the present invention; [Figure 9] 1 is an exploded structural schematic diagram of a resilient fork mechanism according to the present invention; [Figure 10] 1 is a schematic diagram of the three-dimensional structure of the elastic fork mechanism according to the present invention after the ratchet is attached. FIG. [Figure 11] 1 is a schematic diagram of the three-dimensional structure of the shift operation system according to the present invention, with the shift operation gear group and the shift control mechanism hidden. FIG. [Figure 12] 1 is an exploded structural schematic diagram of the shift control mechanism according to the present invention, with the wire controller hidden; FIG. [Figure 13] 1 is a schematic diagram of the three-dimensional structure of the shift control mechanism according to the present invention after the wire controller is hidden. FIG. [Figure 14] 1 is a schematic diagram of the three-dimensional structure of the adjusting screw according to the present invention; [Figure 15] FIG. 10 is a schematic diagram of the three-dimensional structure of the present invention at another viewing angle. DETAILED DESCRIPTION OF THE INVENTION

[0021] In order to facilitate understanding by those skilled in the art, the present invention will be further described below with reference to examples and accompanying drawings, but the contents mentioned in the embodiments are not intended to limit the present invention. The present invention will be described in detail below with reference to the drawings.

[0022] 1 to 15, a transmission including a box-type transmission and a shift operation system is shown. The box-type transmission includes a housing 400, a main shaft 05 and a counter shaft 06 mounted in parallel to the housing 400, at least one main shaft gear 07 is mounted on the main shaft 05, a counter shaft gear 08 meshing with the main shaft gear 07 is mounted on the counter shaft 06, a ratchet 01 meshing with the main shaft gear 07 is mounted on a slide on the main shaft 05, and / or a ratchet 01 meshing with the counter shaft gear 08 is mounted on the counter shaft 06, and the ratchet 01 is drivingly connected to the shift operation system. The shift operation system includes an elastic fork mechanism 5, a shift guide groove drum rod 6 for moving and driving the elastic fork mechanism 5, a shift operation gear group 7 for rotating and driving the shift guide groove drum rod 6, and a shift control mechanism 8 for rotating and driving the shift operation gear group 7, and the shift guide groove drum rod 6 is rotatably attached to a housing 400, The elastic fork mechanism 5 includes a fork seat 1, a fork arm 3 rotatably connected to the fork seat 1, and an elastic member 2 for resetting and driving the fork arm 3. When the fork arm 3 swings relative to the fork seat 1, the elastic member 2 drives and resets the fork arm 3. A shift guide groove 61 is provided on the circumferential surface of the shift guide groove drum rod 6, a fork convex post 13 is provided on the upper end of the fork seat 1, and the fork convex post 13 is movably installed in the shift guide groove 61, and the lower end of the fork arm 3 is movably connected to the ratchet 01.

[0023] Specifically, the elastic fork mechanism 5 and the shift guide groove 61 on the shift guide groove drum rod 6 may be provided in one or more numbers as required. The main shaft gear 07 and the counter shaft gear 08 may be provided in multiple numbers as required, and the main shaft gear 07 and the counter shaft gear 08 may be provided in different sizes and series sizes as required.

[0024] In actual application, the shift control mechanism 8 rotates the shift operation gear group 7, which in turn rotates the shift guide groove drum rod 6, and the shift guide groove 61 drives the fork protrusion 13 to move the elastic fork mechanism 5. During the movement of the elastic fork mechanism 5, if the ratchet of the ratchet 01 collides with the ratchet of the main shaft gear 07 or the countershaft gear 08, the fork arm 3 swings relative to the fork seat 1, and the elastic member 2 constantly drives the fork arm 3 to reset the ratchet 01. The deformation of the elastic member 2 provides the elastic fork mechanism 5 with a retracting function, preventing tooth strikes and sticking when in gear, and allowing the ratchet 01 to mesh with the main shaft gear 07 or the countershaft gear 08 to achieve shifting.

[0025] The present invention employs a rotatable connection between the fork arm 3 and the fork seat 1, and when the fork arm 3 swings relative to the fork seat 1, the elastic member 2 always drives the fork arm 3 to reset, making the fork structure elastic. The elastic fork mechanism 5 acts to release force when driving the ratchet 01 into gear to engage with the main shaft gear 07 or the countershaft gear 08, thereby preventing the ratchet 01 from hitting or getting stuck on the end faces of the main shaft gear 07 or the countershaft gear 08, and preventing damage to the ratchet teeth caused by forcibly pulling the ratchet 01 when the ratchet 01 is disengaged from the main shaft gear 07 or the countershaft gear 08.

[0026] The present invention adopts a rotatable connection between the fork arm 3 and the fork seat 1, which reduces friction when the fork arm 3 swings, making the engagement and disengagement of the ratchet 01 and the main shaft gear 07 or countershaft gear 08 more flexible. When the fork arm 3 swings a small angle relative to the fork seat 1, a large displacement of the ratchet 01 can be achieved. This not only causes less damage than the displacement used in existing rigid forks and some elastic forks, but also has a longer service life. It reduces the elastic deformation of the elastic member 2, prevents premature failure of the elastic member 2, and effectively extends the service life of the elastic member 2, the elastic fork mechanism 5, and the transmission.

[0027] In this embodiment, two slide guide holes 11 are arranged in parallel on the top of the fork seat 1, and the fork seat 1 is fitted onto two guide rods 03 using the slide guide holes 11, and the two guide rods 03 are attached to the housing. When in operation, the fork seat 1 drives the entire elastic fork mechanism and the ratchet 01 to move via the guide rods 03, thereby realizing engagement and disengagement of the ratchet 01 and the main shaft gear 07 or the counter shaft gear 08. Specifically, the two slide guide holes 11 are arranged in parallel, two slide guide holes 11 are provided, and the fork seat 1 is attached to the two guide rods 03. Such a two-guide rod design effectively prevents the fork seat 1 and the entire elastic fork mechanism from shaking or flipping, stabilizes the structure of the transmission, and ensures reliable power transmission.

[0028] In this embodiment, a mounting groove 12 is provided under the fork seat 1, a fork arm connection part 31 is provided on the fork arm 3, and the fork arm connection part 31 is attached to the mounting groove 12 using the fork arm rotation shaft 4, the elastic member 2 is a torsion spring, and a spring body 21 of the torsion spring is attached to the fork arm rotation shaft 4, and an output end head 22 of the torsion spring sandwiches the fork arm connection part 31 and the fork seat 1. Specifically, the fork arm connection part 31 is attached to the fork arm rotation shaft 4, and both ends of the fork arm rotation shaft 4 are attached to the groove walls on both sides of the mounting groove 12, and the fork arm connection part 31 is accommodated within the mounting groove 12, resulting in a compact structure and high stability when the fork arm 3 rotates.

[0029] In this embodiment, a storage groove 311 is provided in the fork arm connection part 31, the fork arm rotation shaft 4 passes through the storage groove 311, the spring body 21 of the torsion spring is mounted in the storage groove 311, and the output end head 22 extends out of the storage groove 311 to clamp the fork seat 1. By mounting the spring body 21 of the torsion spring in the storage groove 311, the spring body is mounted and positioned relative to the torsion spring, which not only stabilizes the structure and ensures reliable mounting, but also makes the elastic fork mechanism 5 more compact.

[0030] In this embodiment, a lower fork portion 32 is installed on the fork arm 3, and extraction pegs 321 are installed on the inside of both ends of the lower fork portion 32, and the extraction pegs 321 are movably installed within the fork grooves 011 on the peripheral surface of the ratchet 01.

[0031] In this embodiment, the shift operation gear group 7 is mounted on the housing 400, and includes a shift operation driven gear 71 mounted on the shift guide groove drum rod 6 and a shift operation drive gear 72 meshing with the shift operation driven gear 71. A return coil spring 73 for resetting and driving the gear is mounted on one side of the shift operation drive gear 72, with one end of the return coil spring 73 connected to the gear wall of the shift operation drive gear 72 and the other end of the return coil spring 73 connected to the mounting shaft of the shift operation drive gear 72. Specifically, the shift control mechanism 8 includes a shift wire 81, a wire adjusting mechanism 82, and a wire controller. A wire mounting groove is formed in the shift operation drive gear 72, with one end of the shift wire 81 circumferentially fitted in the wire mounting groove, and the other end of the shift wire 81 passing through the wire adjusting mechanism 82 and then entering the wire controller. The pull wire controller can be implemented using an existing controller structure, and will not be described further.

[0032] In this embodiment, the wire adjusting mechanism 82 is used to adjust the slack of the shift wire 81. When a shift is required, the wire controller controls the shift wire 81 to rotate the shift operation drive gear 72, and the shift operation drive gear 72 rotates the shift operation driven gear 71, thereby rotating the shift guide groove drum rod 6 and moving the elastic fork mechanism 5 to engage the ratchet 01 with the gear 02, thereby achieving a shift. After the force of the shift wire 81 rotating the shift operation drive gear 72 is released, the return coil spring 73 resets and drives the shift operation drive gear 72.

[0033] This is to overcome the technical problems that the existing wire adjustment mechanism is attached to the frame, which makes it difficult to observe the slack state of the shift wire in the transmission, making adjustment extremely inconvenient, and that after the slack of the shift wire is adjusted, the shift wire is likely to become loose again during use. The present invention further provides a wire adjustment mechanism 82, which includes a mounting seat 100 installed on the transmission housing 400, an adjusting screw 200 connected to the mounting seat 100, and a lock nut 300 connected to the adjusting screw 200, wherein the mounting seat 100 has a base screw hole 101 that communicates with the interior of the transmission housing 400, the adjusting screw 200 has a hollow structure, and an adjusting screw segment 201 is installed on the adjusting screw 200, and the adjusting screw segment 201 is screwed into the base screw hole 101, and the lock nut 300 is fitted into and screwed onto the adjusting screw segment 201, and the elastic fork mechanism 5, shift guide groove drum rod 6, and shift operation gear group 7 are all installed in the transmission housing 400.

[0034] In actual application, one end of the shift wire 81 is routed around the shift operation drive gear 72, and the other end of the shift wire 81 passes through the mounting seat 100 and the adjusting screw 200 before being connected to the wire controller on the side handle of the frame. Immediately after the shift wire 81 is installed, the shift wire 81 is still loose. In this case, the adjusting screw 200 and the lock nut 300 on the adjusting screw segment 201 are simultaneously twisted to shorten the threaded engagement segment between the mounting seat threaded hole 101 of the mounting seat 100 and the adjusting screw segment 201, increasing the length of the adjusting screw segment 201 exposed from the mounting seat threaded hole 101. This increases the length of the adjusting screw segment 201 that can accommodate the shift wire 81 in a sleeved connection, thereby tensioning the shift wire 81. After the shift wire 81 is tensioned, the adjusting screw segment 201 is twisted independently to bring the end face of the adjusting screw segment 201 into contact with the mounting seat 100. In this case, the adjusting screw 200 is unlikely to be screwed solely into the seat body screw hole 101 of the mounting seat 100, thereby realizing locking after the shift wire 81 is tensioned.

[0035] The wire adjustment mechanism 82 employs a mounting base 100 installed on the transmission housing 400, which simplifies the installation of parts such as the adjustment screw 200 and lock nut 300, eliminating the need to install them elsewhere on the bicycle frame or elsewhere. This simplifies installation while also effectively utilizing the installation location, saving additional installation space, and providing a secure, stable structure.

[0036] When the wire adjustment mechanism 82 installs the mounting seat 100 on the transmission housing 400 and adjusts the slack of the shift wire 81 by twisting the adjustment screw segment 201 and the lock nut 300, the slack state of the shift wire 81 in the shift operation drive gear 72 can be observed in real time. This effectively increases the convenience and efficiency of adjusting the shift wire 81 compared to existing wire adjustment devices, thereby improving the overall assembly efficiency of transmission products and reducing labor costs.

[0037] The wire adjustment mechanism 82 adjusts the looseness or tightness of the shift wire 81 by shortening or increasing the threaded engagement length between the adjustment screw 200 and the mounting seat 100. Simply twisting the adjustment screw 200 forward or backward is simple, making it easy for the operator to get started. At the same time, the lock nut 300 is used to lock the shift wire 81, making it less likely to loosen during use. This improves the reliability of the shift control of the gearshift operating mechanism and enhances the overall quality of the transmission product.

[0038] In this embodiment, the adjusting screw 200 further includes a screw head 202 connected to the adjusting screw segment 201, which facilitates screw adjustment and the attachment of other components such as the wire pipe 500. The mounting seat 100 and the transmission housing 400 have an integrally molded structure, specifically, the mounting seat 100 and the transmission housing 400 are machined and molded together, which not only reduces the need for individual machining of components and avoids the cumbersome process of assembling multiple components after machining, but also makes the attachment of components easier and makes the structure more stable after installation.

[0039] In this embodiment, the wire adjusting mechanism 82 further includes a wire pipe 500, and a pipe recess 203 is provided at one end of the screw head portion 202 remote from the adjusting screw segment 201, and one end of the wire pipe 500 is attached to the pipe recess 203. The pipe recess 203 is used to accommodate, mount, and position the wire pipe 500, which is advantageous for threading and tensioning the shift wire 81.

[0040] The above description is merely a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment above, it is not used to limit the present invention. Those skilled in the art can easily make equivalent embodiments that are slightly modified or equivalently changed using the technical content disclosed above, within the scope of the technical solution of the present invention. If the content of the technical solution of the present invention is not deviated from, any simple changes, equivalent changes and modifications made to the above embodiments according to the technology of the present invention all fall within the scope of the technical solution of the present invention.

Claims

1. A transmission including a box-type transmission and a shift operation system, the box-type transmission including a housing (400), a main shaft (05) and a counter shaft (06) mounted in parallel to the housing (400), at least one main shaft gear (07) mounted on the main shaft (05), a counter shaft gear (08) meshing with the main shaft gear (07) mounted on the counter shaft (06), a ratchet (01) meshing with the main shaft gear (07) slide-mounted on the main shaft (05), and / or a ratchet (01) meshing with the counter shaft gear (08) mounted on the counter shaft (06), the ratchet (01) drivingly connected to the shift operation system, The shift operation system includes an elastic fork mechanism (5), a shift guide groove drum rod (6) for moving and driving the elastic fork mechanism (5), a shift operation gear group (7) for rotating and driving the shift guide groove drum rod (6), and a shift control mechanism (8) for rotating and driving the shift operation gear group (7), and the shift guide groove drum rod (6) is rotatably attached to a housing (400), The elastic fork mechanism (5) includes a fork seat (1), a fork arm (3) rotatably connected to the fork seat (1), and an elastic member (2) for resetting and driving the fork arm (3), and when the fork arm (3) swings relative to the fork seat (1), the elastic member (2) drives and resets the fork arm (3); A shift guide groove (61) is provided on the circumferential surface of the shift guide groove drum bar (6), a fork convex post (13) is provided at the upper end of the fork seat (1), the fork convex post (13) is movably installed within the shift guide groove (61), and the lower end of the fork arm (3) is movably connected to a ratchet (01).

2. The box-type transmission further includes a chain wheel (09) attached to the main shaft (05) and cranks (600) attached to both ends of the main shaft (05), 2. The transmission according to claim 1, wherein a lower fork portion (32) is provided on the fork arm (3), and a countersunk rod (321) is provided on the inside of both ends of the lower fork portion (32), and the countersunk rod (321) is movably installed in a fork groove (011) on the circumferential surface of the ratchet (01).

3. The transmission according to claim 1, characterized in that two slide guide holes (11) are installed in parallel on the upper part of the fork seat (1), the fork seat (1) is fitted onto two guide rods (03) using the slide guide holes (11), and the two guide rods (03) are attached to the housing (400).

4. A mounting groove (12) is provided at the bottom of the fork seat (1), a fork arm connecting part (31) is provided at the fork arm (3), and the fork arm connecting part (31) is attached to the mounting groove (12) by using a fork arm rotating shaft (4); 2. The transmission according to claim 1, wherein the elastic member (2) is a torsion spring, a spring body (21) of the torsion spring is attached to the fork arm rotation shaft (4), and an output end head (22) of the torsion spring clamps the fork arm connection portion (31) and the fork seat (1).

5. 5. The transmission according to claim 4, wherein a storage groove (311) is provided in the fork arm connection portion (31), the fork arm rotation shaft (4) passes through the storage groove (311), the spring body (21) of the torsion spring is attached to the storage groove (311), and the output end head (22) clamps the fork seat (1) after projecting from the storage groove (311).

6. 2. The transmission according to claim 1, wherein the shift operation gear group (7) is attached to a housing (400), the shift operation gear group (7) includes a shift operation driven gear (71) attached to a shift guide groove drum rod (6) and a shift operation drive gear (72) meshing with the shift operation driven gear (71), a return coil spring (73) for resetting and driving the gear is installed on one side of the shift operation drive gear (72), one end of the return coil spring (73) is connected to a gear wall of the shift operation drive gear (72), and the other end of the return coil spring (73) is connected to a mounting shaft of the shift operation drive gear (72).

7. 7. The transmission according to claim 6, wherein the shift control mechanism (8) includes a shift wire (81), a wire adjustment mechanism (82), and a wire controller, a wire mounting groove is provided in the shift operation drive gear (72), one end of the shift wire (81) is fitted around the wire mounting groove, and the other end of the shift wire (81) passes through the wire adjustment mechanism (82) and then enters the wire controller.

8. The wire adjustment mechanism (82) includes a mounting seat (100) installed on a transmission housing (400), an adjustment screw (200) connected to the mounting seat (100), and a lock nut (300) connected to the adjustment screw (200); The mounting seat (100) has a seat body screw hole (101) that communicates with the inside of the transmission housing (400). The adjusting screw (200) has a hollow structure, and an adjusting screw segment (201) is installed on the adjusting screw (200). The adjusting screw segment (201) is threaded into the seat body screw hole (101), and the lock nut (300) is fitted onto the adjusting screw segment (201) and threaded onto the adjusting screw segment (201); The transmission according to claim 7, wherein the elastic fork mechanism (5), the shift guide groove drum rod (6), and the shift operation gear group (7) are all installed within the transmission housing (400).

9. 9. The transmission according to claim 8, wherein the adjusting screw (200) further includes a screw head portion (202) connected to the adjusting screw segment (201), and the mounting seat (100) and the transmission housing (400) are integrally molded.

10. 10. The transmission according to claim 9, wherein the wire adjusting mechanism (82) further includes a wire pipe (500), a pipe recess (203) is provided at one end of the screw head portion (202) away from the adjusting screw segment (201), and one end of the wire pipe (500) is attached to the pipe recess (203).

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