Tricycle gear shifting gearbox

Abstract

The utility model discloses a tricycle gear shifting gear box which comprises a box body detachably connected with an engine, a connecting bevel gear arranged in the box body and connected with an output shaft of the engine, a gear shifting assembly connected with the connecting bevel gear and a reversing gear set connected with the gear shifting assembly. The reversing gear set comprises a reversing driving gear, an idle gear tooth and a reversing driven gear which are arranged side by side and sequentially connected in a meshed mode, the reversing driven gear is sleeved with a rear output shaft, and the rear output shaft horizontally extends out and is connected with a differential mechanism in the middle of a rear axle. The box body is arranged outside the engine to achieve gear shifting of advancing and reversing, the steering gear set transfers the position of the rear output shaft to the position in the middle relative to the rear axle during gear shifting so that the rear output shaft can be connected with the differential mechanism in the middle of the rear axle, and therefore the stability of gear shifting and steering of the tricycle is improved.

Description

Technical Field

[0001] This utility model relates to the field of mechanical manufacturing technology, and in particular to a gear shift box for a tricycle. Background Technology

[0002] Currently, because the output end of the gearbox is usually located on the left or right side, while the reduction gearbox of a tricycle is mostly installed in the middle or right side of the engine, in order to ensure transmission efficiency, the rear axle differential is directly connected to the output end of the reduction gearbox. In this case, the installation position of the rear axle differential is to the left or right relative to the rear axle, and is not in the center of the rear axle. As a result, the stability of the tricycle is poor when moving forward or backward, especially when turning. Utility Model Content

[0003] In view of the shortcomings of the prior art, the technical problem to be solved by this utility model is to provide a three-wheeled vehicle shift gearbox that can be easily adjusted for forward and reverse gears and can be connected to the differential at the center position of the rear axle.

[0004] To solve the above-mentioned technical problems, the present invention provides a three-wheeled vehicle shift gearbox, including a housing detachably connected to the engine, a connecting bevel gear disposed in the housing and connected to the engine output shaft, a shift assembly connected to the connecting bevel gear, and a reversing gear set connected to the shift assembly. The reversing gear set includes a reversing driving gear, an idler gear, and a reversing driven gear arranged side by side and meshing sequentially. A rear output shaft is sleeved on the reversing driven gear, and the rear output shaft extends horizontally and is connected to the differential in the middle of the rear axle.

[0005] With the above structure, the housing for the gear shifting components can be detachably installed on the engine, which is convenient for disassembly and maintenance. At the same time, a reversing gear set connected to the gear shifting components is also provided in the housing. The reversing gear set installs the rear output shaft in a position relative to the center of the rear axle and connects it with the differential in the middle of the rear axle for transmission. This improves the stability of the tricycle when turning while ensuring normal use of the tricycle.

[0006] To facilitate installation and simplify the structure, preferably, one side of the housing is connected to the engine by a rear suspension bolt, and the other side of the housing is provided with a drive shaft that is connected to a connecting bevel gear. The protruding end of the drive shaft extends into the engine and is connected to the engine output shaft.

[0007] To achieve rapid shifting between forward and reverse gears while simplifying the structure, the shifting assembly preferably includes a shift shaft rotatably passing through one side of the housing, a driven bevel gear assembly disposed on the other side of the housing and meshing with connecting bevel gears, a pushing assembly disposed on the shift shaft and connected to the driven bevel gear assembly, and a limiting assembly disposed within the housing to limit the rotation of the shift shaft. A pedal is fixedly connected to the side of the shift shaft extending out of the housing. The driven bevel gear assembly includes a rotating shaft with both ends respectively fitted with bearings embedded within the housing, and a component fixedly sleeved on the rotating shaft. The first bevel tooth, the second bevel tooth, and the reversing drive tooth are provided. The tooth grooves of the first bevel tooth and the second bevel tooth are arranged facing each other and are both meshed with the connecting bevel tooth. A shift sleeve is provided on the rotating shaft at the position between the first bevel tooth and the second bevel tooth. A first transmission tooth groove is provided on one side of the shift sleeve along the circumferential direction, and a second transmission tooth groove is provided on the other side of the shift sleeve along the circumferential direction. A guide groove is provided on the shift sleeve at the position between the two transmission tooth grooves along the circumferential direction. The guide groove is abutted against the corresponding position of the push assembly.

[0008] To facilitate use and simplify the installation structure, preferably, a first clearance groove is provided on the first bevel tooth at the position corresponding to the first transmission tooth groove, and a plurality of first protrusions are arranged around the groove wall of the first clearance groove in a circumferential direction, with the gap between two adjacent first protrusions matching the tooth groove gap of the first transmission tooth groove; a second clearance groove is provided on the second bevel tooth at the position corresponding to the second transmission tooth groove, and a plurality of second protrusions are arranged around the groove wall of the second clearance groove in a circumferential direction, with the gap between two adjacent second protrusions matching the tooth groove gap of the second transmission tooth groove.

[0009] To facilitate synchronous rotation and simultaneously limit the shifting between forward and reverse gears, the pushing assembly preferably includes a shift ratchet fixed to the shift shaft. A protruding sleeve is provided on one side of the shift ratchet and fitted onto the outside of the shift shaft. A lever plate is fitted onto the outside of the protruding sleeve. A positioning groove is provided on one side of the shift ratchet surface, and a clearance groove is provided on the other side. A protruding lever block is provided on one side of the lever plate. One side of the lever block extends into the guide groove and abuts against the groove wall on one side of the guide groove. The other side of the lever block is inserted into the clearance groove. One side of the inserted end of the lever block abuts against the groove wall on one side of the clearance groove, and the other side of the inserted end of the lever block is spaced apart from the groove wall on the other side of the clearance groove.

[0010] To facilitate the limiting plate and simplify the installation structure, the limiting assembly preferably includes a mounting hole on the inner side wall of the housing, a compression spring disposed in the mounting hole, and a positioning block. One side of the compression spring abuts against the bottom of the mounting hole, and the other side of the compression spring abuts against the bottom of the positioning hole disposed on one side of the positioning block. The other side of the positioning block protrudes from the mounting hole, and a first insert is provided on one side of the protruding end of the positioning block, and a second insert is provided on the other side of the protruding end. The first insert is inserted into the positioning tooth groove.

[0011] To facilitate the movement of the limiting block, preferably, a limiting groove is provided on the shift plate at the position corresponding to the second insert block. The second insert block is inserted into the limiting groove so as to limit the movement of the limiting block and prevent the shift sleeve from moving.

[0012] To better prevent the positioning block from falling off and to facilitate installation, preferably, a cover is provided on the housing at the position corresponding to the positioning block, and a downwardly extending limiting pin is provided on the inner side wall of the cover; a positioning groove is provided on the positioning block at the position corresponding to the limiting pin, and the protruding end of the limiting pin is inserted into the positioning groove.

[0013] To effectively limit the rotation range of the pedal, preferably, the shift shaft extends out of the housing on the side away from the pedal. The end of the shift shaft is fixedly fitted with an upwardly extending rocker plate, and the extended end of the rocker plate is provided with a protruding guide pin. A connecting plate is provided on the housing cover at the position corresponding to the shift block. A positioning pin is provided on the connecting plate, and a pull plate is fitted on the positioning pin. A guide strip hole is provided on the pull plate at the position corresponding to the guide pin, and the guide pin extends into the guide strip hole.

[0014] To facilitate stable air pressure inside the chamber, it is preferable to provide a vent pipe on the chamber cover that communicates with the inner cavity of the chamber.

[0015] Beneficial effects: This utility model sets up a housing outside the engine to realize forward and reverse gear shifting. At the same time as shifting gears, the steering gear set moves the position of the rear output shaft to a position relative to the center of the rear axle so that the rear output shaft can be connected to the differential in the middle of the rear axle, thereby improving the stability of the tricycle's gear shifting and steering. Attached Figure Description

[0016] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0017] Figure 1 This is an installation diagram of the present invention.

[0018] Figure 2 This is a schematic diagram of the installation structure of the steering gear assembly.

[0019] Figure 3 for Figure 2 View A in the diagram.

[0020] Figure 4 This is a schematic diagram of the installation structure inside the enclosure.

[0021] Figure 5 for Figure 4 View B in the diagram.

[0022] Figure 6 This is a schematic diagram of the connection structure between the bevel gear and the reversing gear set.

[0023] Figure 7 This is a schematic diagram of the installation structure of the shaft and bearing.

[0024] Figure 8 This is a schematic diagram of the structure of the first and second bevel teeth.

[0025] Figure 9 This is a schematic diagram of the connection structure between the shift shaft and the pull plate.

[0026] Figure 10 This is a schematic diagram of the dial plate.

[0027] Figure 11 This is a schematic diagram of the shift ratchet.

[0028] Figure 12 This is a schematic diagram of the positioning block.

[0029] The meanings of the labels in the attached diagram are as follows:

[0030] Box body-1; Rear suspension-10; Mounting hole-11; Baffle-110; Compression spring-12; Positioning block-13; Positioning hole-131; Positioning groove-132; First insert-133; Second insert-134; Positioning pin-14; Pull plate-15; Guide strip hole-151; Box cover-16; Limit pin-17; Vent pipe-18;

[0031] Housing-2; Connecting bevel gear-20; Drive shaft-21; Shift shaft-22; Paddle plate-23; Paddle block-231; Limit groove-232; Shift ratchet-24; Positioning tooth groove-241; Clearance tooth groove-242; Rocking plate-25; Guide pin-251; Pedal-26;

[0032] Rotating shaft-3; Shift sleeve-30; First transmission tooth groove-301; Second transmission tooth groove-302; Guide groove-303; First bevel tooth-31; First clearance groove-311; First protrusion-312; Second bevel tooth-32; Second clearance groove-321; Second protrusion-322;

[0033] Reversing drive gear - 41; idler gear gear - 42; reversing driven gear - 43; rear output shaft - 44. Detailed Implementation

[0034] Depend on Figures 1 to 12 As shown, this utility model includes a housing 2 detachably connected to an engine 1, a connecting bevel gear 20 disposed inside the housing 2 and connected to the engine output shaft, a shift assembly connected to the connecting bevel gear 20, and a reversing gear set connected to the shift assembly. The reversing gear set includes a reversing driving gear 41, an idler gear 42, and a reversing driven gear 43 arranged side by side and meshing sequentially. A rear output shaft 44 is sleeved on the reversing driven gear 43. The rear output shaft 44 extends horizontally and is connected to the differential in the middle of the rear axle.

[0035] Specifically, one side of the housing 2 is screwed to the engine 1 by the rear suspension 10, and the other side of the housing 2 is provided with a drive shaft 21 connected to the connecting bevel gear 20. The protruding end of the drive shaft 21 extends into the engine 1 and is connected to the engine output shaft.

[0036] Secondly, the shift assembly includes a shift shaft 22 rotatably passing through one side of the housing 2, a driven bevel gear assembly disposed on the other side of the housing 2 and meshing with the connecting bevel gear 20, a push assembly disposed on the shift shaft 22 and connected to the driven bevel gear assembly, and a limiting assembly disposed within the housing 2 for limiting the rotation of the shift shaft 22. A pedal 26 is fixedly connected to the side of the shift shaft 22 extending out of the housing 2. The driven bevel gear assembly includes a rotating shaft 3 with both ends respectively sleeved with bearings embedded within the housing 2, and a first bevel gear 31, a second bevel gear 32, and a reversing drive gear 41 fixedly sleeved on the rotating shaft 3. The grooves of the first bevel tooth 31 and the second bevel tooth 32 are arranged facing each other and are both meshed with the connecting bevel tooth 20; a shift sleeve 30 is sleeved on the rotating shaft 3 at the position between the first bevel tooth 31 and the second bevel tooth 32, a first transmission groove 301 is wound around one side of the shift sleeve 30 in the circumferential direction, a second transmission groove 302 is wound around the other side of the shift sleeve 30 in the circumferential direction, and a guide groove 303 is wound around the shift sleeve 30 at the position between the two transmission grooves in the circumferential direction, and the guide groove 303 is abutted against the corresponding position of the push assembly.

[0037] Specifically, a first clearance groove 311 is provided on the first bevel tooth 31 at the position corresponding to the first transmission tooth groove 301, and a plurality of first protrusions 312 are arranged around the groove wall of the first clearance groove 311 in the circumferential direction, and the gap between two adjacent first protrusions 312 is adapted to the tooth groove gap of the first transmission tooth groove 301; a second clearance groove 321 is provided on the second bevel tooth 32 at the position corresponding to the second transmission tooth groove 302, and a plurality of second protrusions 322 are arranged around the groove wall of the second clearance groove 321 in the circumferential direction, and the gap between two adjacent second protrusions 322 is adapted to the tooth groove gap of the second transmission tooth groove 302.

[0038] Furthermore, the actuating assembly includes a shift ratchet 24 fixed on the shift shaft 22. A protrusion sleeve is provided on one side of the shift ratchet 24 and sleeved on the outside of the shift shaft 22. A shift plate 23 is sleeved on the outside of the protrusion sleeve. A positioning tooth groove 241 is provided on one side of the surface of the shift ratchet 24, and a clearance tooth groove 242 is provided on the other side of the surface of the shift ratchet 24. A protruding shift block 231 is provided on one side of the shift plate 23. One side of the shift block 231 extends into the guide groove 303 and abuts against the groove wall on one side of the guide groove 303. The other side of the shift block 231 is inserted into the clearance tooth groove 242. One side of the inserted end of the shift block 231 abuts against the groove wall on one side of the clearance tooth groove 242, and the other side of the inserted end of the shift block 231 is spaced apart from the groove wall on the other side of the clearance tooth groove 242.

[0039] Next, the limiting assembly includes a mounting hole 11 on the inner wall of the housing 2, a compression spring 12 disposed in the mounting hole 11, and a positioning block 13. One side of the compression spring 12 abuts against the bottom of the mounting hole 11, and the other side of the compression spring 12 abuts against the bottom of the positioning hole 131 disposed on one side of the positioning block 13. The other side of the positioning block 13 protrudes from the mounting hole 11. A first insert 133 is provided on one side of the protruding end of the positioning block 13, and a second insert 134 is provided on the other side of the protruding end. The first insert 133 is inserted into the positioning tooth groove 241. In addition, a limiting groove 232 is provided on the shift plate 23 at the position corresponding to the second insert 134. The second insert 134 is inserted into the limiting groove 232 to limit the movement of the shift block 231 and prevent the shift sleeve 30 from moving.

[0040] In addition, the shift shaft 22 extends out of the housing 2 on the side away from the pedal 26. The end of the shift shaft 22 is fixedly fitted with an upwardly extending rocker plate 25. A protruding guide pin 251 is provided at the extended end of the rocker plate 25. A connecting plate is provided on the housing cover 16 at the position corresponding to the rocker plate 25. A positioning pin 14 is provided on the connecting plate. A pull plate 15 is fitted on the positioning pin 14. A guide strip hole 151 is provided on the pull plate 15 at the position corresponding to the guide pin 251. The guide pin 251 extends into the guide strip hole 151.

[0041] A cover 16 is provided on the box body 2 at the position corresponding to the positioning block 13. A vent pipe 18 communicating with the inner cavity of the box body 2 is provided on the cover 16. A downwardly extending limiting pin 17 is provided on the inner side wall of the cover 16. A positioning groove 132 is provided on the positioning block 13 at the position corresponding to the limiting pin 17. The extended end of the limiting pin 17 is inserted into the positioning groove 132.

[0042] The working principle of this utility model is as follows:

[0043] like Figure 1 , Figure 2 and Figure 6 As shown, one end of the drive shaft 21 is first inserted into the engine 1 and connected to the engine output shaft. Then, the other end of the drive shaft 21 is inserted into the housing 2. The inserted end of the drive shaft is connected to the connecting bevel gear 20. At this time, the housing 2 is rotated and the rear suspension 10 fixes the housing 2 to the outside of the engine 1. Then, the shift assembly and the reversing gear set are installed in sequence. The shift plate 23 is provided with two limiting grooves 232 corresponding to forward and reverse. The shift ratchet 24 is also provided with two positioning grooves 241 corresponding to the limiting grooves 232. At this time, the reversing active gear 41 is fixedly sleeved with the rotating shaft 3. The reversing active gear 41, the idler gear 42 and the reversing driven gear 43 are arranged side by side in the housing 2 and meshed in sequence. The rear output shaft 44 is sleeved on the reversing driven gear 43. The rear output shaft 44 extends horizontally and is connected to the differential in the middle of the rear axle.

[0044] In use, the first bevel tooth 31 is in reverse gear and the second bevel tooth 32 is in forward gear. When the tricycle is moving forward, the connecting bevel tooth 20 drives the first bevel tooth 31 and the second bevel tooth 32 to rotate simultaneously, and the rotation directions of the first bevel tooth 31 and the second bevel tooth 32 are opposite. At this time, the second transmission tooth groove 302 on the shift sleeve 30 moves into the second clearance groove 321. The tooth groove clearance of the second transmission tooth groove 302 matches the clearance between the second protrusions 322. (Refer to...) Figures 4 to 6As shown in the diagram, when starting, pressing the left side of the pedal 26 causes the shift block 231 to rotate to the right within the guide groove 303 via the clearance groove 242, and abuts against the right side wall of the guide groove 303, causing the shift sleeve 30 to move towards the second bevel tooth 32. After the shift sleeve 30 moves into position, the pedal 26 is released, and the shift ratchet 24 and the rotating shaft 22 rotate back a distance synchronously. At this time, there is a gap between the left side of the clearance groove 242 and the left side of the shift block 231, and the right side of the clearance groove 242 abuts against the right side of the shift block 231. At the same time, the first insert 133 on the positioning block 13 is inserted into the positioning groove 241 at the lower position of the shift ratchet 24, and the second insert 134 is inserted into the limiting groove 232 at the lower position of the shift plate 23. Thus, the positioning setting of the compression spring 12 within the guide groove 303 can prevent the shift sleeve 30 from rotating, shifting, or becoming loose.

[0045] When it is necessary to shift to reverse gear, the right side of the pedal 26 is pressed, causing the shift shaft 22 to rotate clockwise. This drives the shift plate 23, shift block 231, and shift ratchet 24 to rotate synchronously in the same direction. The rotation of the shift block 231 abuts against the groove wall on the other side of the guide groove 303, and drives the shift sleeve 30 to move toward the first bevel tooth 31. Then, the first transmission tooth groove 301 moves into the first clearance groove 311. Since the tooth groove clearance of the first transmission tooth groove 301 is adapted to the clearance between the adjacent first protrusion 322, the first bevel tooth 31 and the shift sleeve 30 are meshed and connected. This causes the shift sleeve 30 to drive the rotating shaft 3 to rotate in the opposite direction, which in turn drives the reversing drive tooth 41 to rotate in the opposite direction. Thus, the meshing transmission drives the idler tooth 42, the reversing driven tooth 43, and the rear output shaft 44 to rotate in the opposite direction, realizing the reversing operation of the tricycle.

[0046] During this gear shift, such as Figures 3 to 8 as well as Figures 10 to 12As shown in the diagram, when the pedal 26 is pressed in the direction shown, the shift shaft 22 rotates clockwise. The left side of the clearance groove 242 abuts against the right side of the shift block 231, while there is a gap between the right side of the clearance groove 242 and the right side of the shift block 231. When the shift ratchet 24 rotates synchronously, the inclined surface of the groove wall of the positioning groove 241 at the lower part of the shift ratchet 24 slides relative to the outer wall of the first insert block 133, thereby causing the positioning block 13 to move into the mounting hole 11 and compress the compression spring 12. When the right side of the clearance groove 242 abuts against the right side of the shift block 231, the shift plate 23 rotates synchronously. As the shift shaft 22 continues to rotate, the shift block 231 rotates to the left side of the guide groove 303 and abuts against the left side groove wall, causing the shift sleeve 30 to begin moving towards the first bevel tooth 31, tightening... Next, the first transmission tooth groove 301 begins to move into the first clearance groove 311, and the first bevel tooth 31 engages with the shift sleeve 30, stopping the movement of the shift plate 23 and the shift ratchet 24. At the same time, the outer wall of the first insert 133 has moved into another positioning tooth groove 241 adjacent to the upper part of the shift ratchet 24, and relative sliding is formed between the outer wall of the first insert 133 and the groove wall of the corresponding positioning tooth groove 241. Under the elastic force of the compression spring 12, the positioning block 13 moves to the outside of the mounting hole 11, and the first insert 133 is inserted into the positioning tooth groove 241 at the upper position of the shift ratchet 24. At the same time, the second insert 134 is also inserted into the limiting groove 232 at the upper position of the shift plate 23. Thus, under the elastic force of the compression spring 12, the rotation of the shift plate 23 and the shift ratchet 24 is limited again.

[0047] And in this process, such as Figure 4 and Figure 9 As shown, the protruding end of the limiting pin 17 is inserted into the positioning groove 132 to limit the horizontal movement of the positioning block 13 in the horizontal direction; similarly, the rocker plate 25 outside the housing 2 also rotates synchronously with the shift shaft 22, and drives the guide pin 251 to move in the guide strip hole 151 to limit the rotation of the pedal 26, so as to prevent the positioning block 13 from limiting the shift plate 23 and the shift ratchet 24 from failing; wherein, a limiting boss 141 is provided on the positioning pin 14 to prevent the pull plate 15 from falling off.

[0048] By repeating this process, the power output position is transferred to the rear output shaft 44 while switching between forward and reverse gears, which corresponds to the differential located in the center of the rear axle, thus helping to improve the turning stability of the tricycle.

[0049] It should be noted that, as Figures 3 to 5 As shown, to facilitate the installation and removal of the positioning block 13, the mounting hole 11 is set as a through hole on the inner side wall of the housing 2, and the mounting hole 11 is located on the inner side wall of the housing 2. Figure 5A baffle 110 is screwed to one side at the position indicated by the dashed line. The non-screwed end of the baffle 110 serves as the bottom of the mounting hole, that is, one side of the compression spring 12 abuts against the inner wall of the baffle 110.

[0050] In addition, a spline groove is provided on the shift shaft 22 at the position corresponding to the shift plate 23, and a spline groove is also provided on the rotating shaft 3 at the position corresponding to the shift sleeve 30 and the reversing drive gear 41, so as to achieve synchronous rotation; wherein, the shift plate 23 and the reversing drive gear 41 are tightly fitted and fixedly installed at the spline groove position.

Claims

1. A gearbox for a tricycle, characterized in that: The device includes a housing (2) detachably connected to the engine (1), a connecting bevel gear (20) disposed inside the housing (2) and connected to the engine output shaft, a shift assembly connected to the connecting bevel gear (20), and a reversing gear set connected to the shift assembly. The reversing gear set includes a reversing driving gear (41), an idler gear (42), and a reversing driven gear (43) arranged side by side and meshed in sequence. A rear output shaft (44) is fitted on the reversing driven gear (43). The rear output shaft (44) extends horizontally and is connected to the differential in the middle of the rear axle.

2. The gearbox for a tricycle as described in claim 1, characterized in that: One side of the housing (2) is screwed to the engine (1) by a rear suspension (10), and the other side of the housing (2) is provided with a drive shaft (21) connected to the connecting bevel gear (20). The protruding end of the drive shaft (21) extends into the engine (1) and is connected to the engine output shaft.

3. A tricycle gearbox as described in claim 1, characterized in that: The shift assembly includes a shift shaft (22) rotatably passing through one side of the housing (2), a driven bevel gear assembly located on the other side of the housing (2) and meshing with a connecting bevel gear (20), a push assembly located on the shift shaft (22) and connected to the driven bevel gear assembly, and a limiting assembly located in the housing (2) for limiting the rotation of the shift shaft (22). A pedal (26) is fixedly connected to the side of the shift shaft (22) that extends out of the housing (2). The driven bevel gear assembly includes a rotating shaft (3) with both ends respectively sleeved with bearings embedded in the housing (2), and a first bevel gear (31), a second bevel gear (32), and a reversing drive gear (41) fixedly sleeved on the rotating shaft (3). The tooth grooves of the first bevel tooth (31) and the second bevel tooth (32) are arranged facing each other and are both meshed with the connecting bevel tooth (20); a shift sleeve (30) is sleeved on the rotating shaft (3) at the position between the first bevel tooth (31) and the second bevel tooth (32). A first transmission tooth groove (301) is wound around one side of the shift sleeve (30) in the circumferential direction, and a second transmission tooth groove (302) is wound around the other side of the shift sleeve (30) in the circumferential direction. A guide groove (303) is wound around the shift sleeve (30) at the position between the two transmission tooth grooves in the circumferential direction. The guide groove (303) is abutted against the corresponding position of the push assembly.

4. A tricycle gearbox as described in claim 3, characterized in that: A first clearance groove (311) is provided on the first bevel tooth (31) at the position corresponding to the first transmission tooth groove (301). A plurality of first protrusions (312) are arranged around the groove wall of the first clearance groove (311) in the circumferential direction. The gap between two adjacent first protrusions (312) is adapted to the tooth groove gap of the first transmission tooth groove (301). A second clearance groove (321) is provided on the second bevel tooth (32) at the position corresponding to the second transmission tooth groove (302). A plurality of second protrusions (322) are arranged around the groove wall of the second clearance groove (321) in the circumferential direction. The gap between two adjacent second protrusions (322) is adapted to the tooth groove gap of the second transmission tooth groove (302).

5. A tricycle gearbox as described in claim 3, characterized in that: The pushing assembly includes a shift ratchet (24) sleeved on the shift shaft (22). A protrusion sleeve is provided on one side of the shift ratchet (24) and fitted onto the outside of the shift shaft (22). A shift plate (23) is sleeved on the outside of the protrusion sleeve. A positioning groove (241) is provided on one side of the surface of the shift ratchet (24), and a clearance groove (242) is provided on the other side of the surface of the shift ratchet (24). A positioning groove (241) is provided on one side of the shift plate (23). There is a protruding lever (231), one side of which extends into the guide groove (303) and abuts against the groove wall on one side of the guide groove (303). The other side of the lever (231) is inserted into the relief tooth groove (242). One side of the inserted end of the lever (231) abuts against the groove wall on one side of the relief tooth groove (242), and the other side of the inserted end of the lever (231) is separated from the groove wall on the other side of the relief tooth groove (242).

6. A tricycle gearbox as described in claim 5, characterized in that: The limiting component includes a mounting hole (11) on the inner side wall of the housing (2), a compression spring (12) in the mounting hole (11), and a positioning block (13). One side of the compression spring (12) abuts against the bottom of the mounting hole (11), and the other side of the compression spring (12) abuts against the bottom of the positioning hole (131) on one side of the positioning block (13). The other side of the positioning block (13) protrudes from the mounting hole (11). One side of the protruding end of the positioning block (13) is provided with a first insert (133), and the other side of the protruding end is provided with a second insert (134). The first insert (133) is inserted into the positioning tooth groove (241).

7. A tricycle gearbox as described in claim 6, characterized in that: A limiting groove (232) is provided on the shift plate (23) at the position corresponding to the second insert (134). The second insert (134) is inserted into the limiting groove (232) to limit the movement of the shift block (231) and prevent the shift sleeve (30) from moving.

8. A tricycle gearbox as described in claim 6, characterized in that: A cover (16) is provided on the box body (2) at the position corresponding to the positioning block (13), and a downwardly extending limiting pin (17) is provided on the inner side wall of the cover (16); a positioning groove (132) is provided on the positioning block (13) at the position corresponding to the limiting pin (17), and the protruding end of the limiting pin (17) is inserted into the positioning groove (132).

9. A tricycle gearbox as described in claim 8, characterized in that: The shift shaft (22) extends out of the housing (2) on the side away from the pedal (26). The end of the shift shaft (22) is fixedly fitted with an upwardly extending rocker plate (25). A protruding guide pin (251) is provided at the extended end of the rocker plate (25). A connecting plate is provided on the housing cover (16) at the position corresponding to the rocker plate (25). A positioning pin (14) is provided on the connecting plate. A pull plate (15) is fitted on the positioning pin (14). A guide strip hole (151) is provided on the pull plate (15) at the position corresponding to the guide pin (251). The guide pin (251) extends into the guide strip hole (151).

10. A tricycle shift gearbox as described in claim 9, characterized in that: A vent pipe (18) communicating with the inner cavity of the box body (2) is provided on the box cover (16).

Images