A drive assembly, a mid-transmission and a bicycle

Abstract

The present application relates to the technical field of transmission, and provides a driving assembly, a mid-mounted transmission and a bicycle. The driving assembly provided by the present application comprises a fork and control members installed at both ends of the fork; the fork is used for sleeving a clutch of the mid-mounted transmission; and the control members are used for driving the fork to move synchronously along the axial direction at both ends of the fork, so as to drive the clutch to move along the axial direction. The synchronous movement of both ends of the fork can balance the force of both ends of the fork, solve the cantilever problem of the fork, and thus the fork can be stably clamped on the clutch when driving the clutch to move along the axial direction, and the stability of the clutch during movement is improved.

Description

Technical Field

[0001] This invention relates to the field of transmission technology, and in particular to a drive assembly, a mid-mounted transmission, and a bicycle. Background Technology

[0002] In the field of bicycles or e-bikes, a mid-drive derailleur refers to a derailleur installed in the middle of the bicycle and powered by pedals. A mid-drive derailleur achieves gear changes by locking and disengaging the clutch and gears to create different transmission routes. The drive assembly is used to move the clutch. However, in existing technologies, the drive assembly cannot stably clamp onto the clutch during movement, resulting in poor clutch stability. Summary of the Invention

[0003] The purpose of this invention is to provide a solution to the technical problem of poor stability of the clutch in a mid-mounted transmission during movement in the prior art.

[0004] In a first aspect, this application provides a drive assembly, including a shift fork and control components mounted at both ends of the shift fork; the shift fork is used to be sleeved on the clutch of a mid-mounted transmission; the control components are used to drive the shift fork so that both ends of the shift fork move synchronously along the axial direction, thereby driving the clutch to move along the axial direction.

[0005] In one embodiment, the shift fork has a first mounting hole and a second mounting hole, the first mounting hole and the second mounting hole are connected, the size of the first mounting hole is larger than the outer diameter of the clutch, and the second mounting hole is used to engage with the clutch.

[0006] In one embodiment, the thickness of the fork at the second mounting hole is less than the thickness of the fork at the first mounting hole.

[0007] In one embodiment, the control element includes two control shafts, which are respectively mounted on both ends of the shift fork.

[0008] In one embodiment, the control component further includes a positioning element mounted on the control shaft, and the drive assembly further includes a connector axially movably mounted on the control shaft. The shift fork is mounted on the connector. The connector has protrusions and / or grooves, and the control shaft is used to abut against the protrusions and / or grooves through the positioning element during rotation to push the connector to move, thereby driving the shift fork to move axially.

[0009] In one embodiment, the connecting member includes a first shift fork ring, a second shift fork ring, and a third shift fork ring; the first shift fork ring, the second shift fork ring, and the third shift fork ring are all axially movably sleeved on the control shaft, and each has the protrusion and / or the groove; the first shift fork ring and the third shift fork ring are respectively located at both ends of the second shift fork ring, and the first shift fork ring and the third shift fork ring are connected; the shift fork is mounted on the second shift fork ring; the positioning member is used to push the first shift fork ring, the second shift fork ring, and the third shift fork ring to move in the same direction or in opposite directions by abutting against the protrusion and / or the groove.

[0010] In one embodiment, the first shift fork ring has a first protrusion, and the second shift fork ring has a second groove on one side. The positioning member is used to sequentially abut against the first protrusion and the second groove during the rotation of the control shaft to push the shift fork to move to one side from the initial position, and to sequentially leave the second groove and the first protrusion during the rotation of the control shaft to push the shift fork back to the initial position.

[0011] In one embodiment, the third shift fork ring is provided with a third protrusion, and the other side of the second shift fork ring is provided with a fourth groove. The positioning member is used to sequentially abut against the third protrusion and the fourth groove during the rotation of the control shaft to push the shift fork from the initial position to the other side, and to sequentially leave the fourth groove and the third protrusion during the rotation of the control shaft to push the shift fork back to the initial position.

[0012] In one embodiment, the positioning element includes a first positioning pin and a second positioning pin, the first positioning pin being located between the first shift fork ring and the second shift fork ring, and the second positioning pin being located between the second shift fork ring and the third shift fork ring.

[0013] In one embodiment, the drive assembly further includes an elastic member with its two ends respectively abutting against the connector and the fork. The elastic member is configured to be in a compressed state when the positioning member pushes the connector, thereby pushing the fork or the connector to move when it returns to a normal state.

[0014] In one embodiment, the connector further includes a connecting post, which passes through the shift fork and is fixedly connected at both ends to the first shift fork ring and the third shift fork ring, respectively.

[0015] In one embodiment, the elastic element includes a first elastic element and a second elastic element sleeved on the connecting post. The two ends of the first elastic element abut against one side of the first shift fork ring and the shift fork, respectively, and the two ends of the second elastic element abut against the other side of the third shift fork ring and the shift fork, respectively.

[0016] In a second aspect, this application provides a mid-mounted transmission, including a main shaft, a countershaft parallel to the main shaft, a transmission mechanism, a clutch, an output mechanism, and a drive assembly as described in the first aspect above;

[0017] The speed change mechanism includes at least one main gear mounted on the main shaft and at least one secondary gear mounted on the secondary shaft, wherein each main gear meshes with a corresponding secondary gear;

[0018] The clutch is mounted on the main shaft, and the drive assembly is used to drive the clutch to move axially, thereby controlling the locking or disengagement of each of the main gears from the main shaft through the clutch, so as to change the transmission route between the main shaft and the output mechanism;

[0019] Alternatively, the clutch is mounted on the secondary shaft, and the drive assembly is used to drive the clutch to move axially, thereby controlling the locking or disengagement of each of the secondary gears from the secondary shaft through the clutch, so as to change the transmission route between the main shaft and the output mechanism.

[0020] In one embodiment, each of the main gears is fixedly mounted on the main shaft, and each of the secondary gears is circumferentially rotatable and axially fixedly mounted on the secondary shaft; the clutch is circumferentially fixed and axially movablely mounted on the secondary shaft, and the drive assembly is used to drive the clutch to move axially so that the clutch engages with the adjacent secondary gear axially.

[0021] In one embodiment, the output mechanism includes an output gear sleeved on the main shaft, the output gear being used to rotate under the drive of the secondary shaft when one of the at least one secondary gear is locked with the secondary shaft, and to rotate under the drive of the main shaft when all the secondary gears are disengaged from the secondary shaft.

[0022] In one embodiment, the output mechanism further includes a one-way clutch assembly for disengaging the output gear from the main shaft when one of the at least one secondary gears is locked to the secondary shaft, and for locking the output gear to the main shaft when all the secondary gears are disengaged from the secondary shaft.

[0023] In one embodiment, the output gear includes an output portion and a clutch portion protruding from the end face of the output portion. The clutch portion extends into the main gear adjacent to the output gear, and the clutch portion is locked or disengaged from the main shaft by the one-way clutch assembly.

[0024] In one embodiment, the one-way clutch assembly is mounted in the main gear adjacent to the output gear; or, the one-way clutch assembly is mounted on the main shaft.

[0025] In one embodiment, the speed change mechanism further includes a transmission gear mounted on the secondary shaft, the transmission gear meshing with the output gear, thereby driving the output gear to rotate.

[0026] In one embodiment, the mid-mounted transmission further includes a torque sensor assembly mounted on the countershaft and connected to the transmission gear.

[0027] In one embodiment, the torque sensor assembly includes a fixing member, a torque measuring member, a first circuit assembly, and a second circuit assembly; the fixing member includes a fixing part circumferentially fixedly mounted on the secondary shaft and a lever arm protruding from the fixing part, the lever arm being connected to the transmission gear, the torque measuring member being mounted on the lever arm, the first circuit assembly being fixedly mounted on the secondary shaft, the first circuit assembly being communicatively connected to the torque measuring member and the second circuit assembly, and the second circuit assembly being sleeved on the secondary shaft and rotatable relative to the first circuit assembly.

[0028] In one embodiment, the first circuit assembly includes a first annular cavity and a first circuit module installed in the first annular cavity, and the second circuit assembly includes a second annular cavity and a second circuit module installed in the second annular cavity; the first annular cavity is fixedly sleeved on the transmission shaft, and the second annular cavity is rotatably sleeved on the outside of the first annular cavity.

[0029] In one embodiment, the mid-mounted transmission further includes a spline sleeve fixedly mounted on the countershaft, the spline sleeve abutting against one side of the counter gear to restrict the axial movement of the counter gear, and the clutch being circumferentially fixed and axially movable mounted on the outside of the spline sleeve.

[0030] In one embodiment, the number of spline sleeves is at least two, and at least one spline sleeve is detachably mounted on the countershaft.

[0031] In one embodiment, the mid-mounted transmission further includes a motor for providing driving force to the output mechanism, the motor and the main shaft being disposed on the same side of the shift fork.

[0032] Thirdly, this application provides a bicycle, including a frame and a mid-mounted derailleur as described in the second aspect above, the mid-mounted derailleur being mounted on the frame.

[0033] The beneficial effects of the drive assembly for the mid-mounted transmission provided by this invention are as follows: The drive assembly includes a shift fork for mounting on the clutch and control components mounted at both ends of the shift fork. The control components drive the shift fork so that both ends of the shift fork move synchronously along the axial direction of the drive shaft, thereby driving the clutch to move axially along the drive shaft. By moving the shift fork synchronously, the forces on both ends of the shift fork can be balanced, solving the cantilever problem of the shift fork. This allows the shift fork to be stably clamped on the clutch when driving the clutch to move axially, improving the stability during clutch movement. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0035] Figure 1 A schematic diagram of a driving component provided in an embodiment of the present invention;

[0036] Figure 2 A schematic diagram of the driving component provided in an embodiment of the present invention from another perspective;

[0037] Figure 3 An assembly diagram of the drive assembly and clutch provided in an embodiment of the present invention;

[0038] Figure 4 This is an assembly diagram of the connector and positioning component of the drive assembly provided in an embodiment of the present invention;

[0039] Figure 5 A schematic diagram of a mid-mounted transmission provided in an embodiment of the present invention;

[0040] Figure 6 This is an assembly diagram of the secondary shaft provided in an embodiment of the present invention;

[0041] Figure 7 This is a schematic diagram of the spline sleeve being assembled on the countershaft according to an embodiment of the present invention;

[0042] Figure 8 This is an assembly diagram of the spline sleeve provided in an embodiment of the present invention;

[0043] Figure 9 This is a schematic diagram of the output mechanism on the spindle provided in an embodiment of the present invention;

[0044] Figure 10 An exploded view of the output mechanism provided in an embodiment of the present invention;

[0045] Figure 11 A cross-sectional view of the spindle at the main gear provided in an embodiment of the present invention;

[0046] Figure 12This is a schematic diagram of the torque sensor assembly on the spindle provided in an embodiment of the present invention;

[0047] Figure 13 An exploded view of the torque sensor assembly provided in an embodiment of the present invention;

[0048] Figure 14 This is a schematic diagram of a mid-mounted transmission provided for another embodiment of the present invention.

[0049] The following are the labeling elements in the figure:

[0050] 10. Drive assembly; 11. Shift fork; 111. First mounting hole; 112. Second mounting hole; 12. Control component; 121. Control shaft; 122. Positioning component; 1221. First positioning pin; 1222. Second positioning pin; 13. Connecting component; 131. First shift fork ring; 1311. First protrusion; 1312. First groove; 132. Second shift fork ring; 1321. Second groove; 1322. Fourth groove; 133. Third shift fork ring; 1331. Third protrusion; 1332. Third groove; 134. Connecting post; 135. First washer; 136. Second washer; 14. Elastic element; 141. First elastic element; 142. Second elastic element; 15. Drive shaft; 16. Gear; 20. Clutch; 30. Main shaft; 40. 50. Secondary shaft; 51. Transmission mechanism; 52. Main gear; 53. Secondary gear; 54. Transmission gear; 55. Clearance hole; 60. Output mechanism; 61. Output gear; 611. Output part; 6111. Gear structure; 6112. Mounting structure; 612. Clutch part; 6121. Fifth groove; 62. One-way clutch assembly; 621. Cage; 622. Roller; 623. Receiving groove; 624. Elastic connector; 63. Bearing part; 70. Spline sleeve; 80. Torque sensor assembly; 81. Sensor fixing part; 811. Fixing part; 812. Lever arm; 82. First circuit assembly; 821. First annular cavity; 83. Second circuit assembly; 831. Second annular cavity; 832. Mounting hole; 90. Motor. Detailed Implementation

[0051] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0052] Throughout this specification, references to "an embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of this application. Therefore, the phrases "in one embodiment" or "in some embodiments" appear in various places throughout the specification, and not all refer to the same embodiment. Furthermore, in one or more embodiments, particular features, structures, or characteristics may be combined in any suitable manner.

[0053] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0054] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0055] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0056] One embodiment of the present invention provides a driving component. Please refer to... Figure 1-4 The driving components in the embodiments of the present invention will now be described.

[0057] The drive assembly 10 provided in this embodiment of the invention is used in a mid-mounted transmission. The mid-mounted transmission includes a clutch 20, which locks or disengages gears to change the transmission route and achieve different gear positions. For example, the clutch 20 is mounted on a drive shaft 15, and a gear 16 is installed on the drive shaft 15. The clutch 20 controls the locking and disengagement of the drive shaft 15 and the gear 16, thereby allowing different gears 16 to be locked and disengaged from the drive shaft 15 to obtain different transmission routes.

[0058] The drive assembly 10 includes a shift fork 11 and control components 12 mounted at both ends of the shift fork 11. The shift fork 11 is fitted onto the clutch 20. The control components 12 drive the shift fork 11, causing both ends of the shift fork 11 to move synchronously along the axial direction, thereby driving the clutch 20 to move axially. By moving the shift fork 11 synchronously at both ends, the forces on both ends of the shift fork 11 can be balanced. Compared to single-end drive of the shift fork 11, this solves the cantilever problem of the shift fork 11 caused by single-end drive, allowing the shift fork 11 to move more smoothly along the axial direction, thus improving the stability of the clutch 20 during movement. Simultaneously, by solving the cantilever problem of the shift fork 11, the design strength requirements for the shift fork 11 and control components 12 can be reduced, improving the reliability of the drive assembly 10. Furthermore, by moving the shift fork 11 synchronously at both ends, the driving force at each end of the shift fork 11 can be reduced to half of the driving force in single-end drive, further reducing the design strength requirements for the shift fork 11. Therefore, the shift fork 11 can operate under greater thrust, enabling the drive assembly 10 to shift gears even when the clutch 20 is under load, thus improving the user's shifting experience.

[0059] In one embodiment, the shift fork 11 has a first mounting hole 111 and a second mounting hole 112, which are connected. The size of the first mounting hole 111 is larger than the outer diameter of the clutch 20, and the second mounting hole 112 is used to engage with the clutch 20. During assembly, the first mounting hole 111 is first fitted onto the clutch 20, and then the clutch 20 is moved towards the second mounting hole 112 to engage the clutch 20 within the second mounting hole 112. This facilitates assembly and allows the shift fork 11 to be more securely engaged with the clutch 20.

[0060] In one embodiment, the thickness of the shift fork 11 at the second mounting hole 112 is less than the thickness of the shift fork 11 at the first mounting hole 111, thereby reducing the engagement width between the clutch 20 and the shift fork 11, and thus reducing the axial dimension of the clutch 20.

[0061] In one embodiment, the control element 12 includes two control shafts 121, which are respectively mounted on both ends of the shift fork 11. By synchronously driving the two control shafts 121, the two ends of the shift fork 11 can be synchronously driven to move.

[0062] In one embodiment, the control component 12 further includes a positioning component 122 mounted on the control shaft 121, and the drive assembly 10 further includes a connector 13 axially movably mounted on the control shaft 121. A shift fork 11 is mounted on the connector 13. The connector 13 has protrusions and / or grooves. The control shaft 121, during rotation, abuts against the protrusions and / or grooves via the positioning component 122 to push the connector 13 to move, thereby driving the shift fork 11 to move axially. The control shaft 121 is used to rotate under the drive of an external force, for example, by a gear or a chain. The axial direction is referenced to the axial direction of the control shaft 121.

[0063] Specifically, since the positioning member 122 is mounted on the control shaft 121, when the control shaft 121 rotates, the positioning member 122 moves circumferentially. As the positioning member 122 moves circumferentially, it abuts against the protrusions or grooves of the connecting member 13, thereby pushing the connecting member 13 to move in different axial directions, which in turn drives the shift fork 11 to move the clutch 20 axially. Therefore, the shift fork 11 can be moved axially by rotating the control shaft 121, without needing to move the control shaft 121 axially. Thus, during the movement of the clutch 20 driven by the shift fork 11, the axial movement distance of the drive assembly 10 is reduced, thereby reducing the size of the mid-mounted transmission.

[0064] In one embodiment, the connecting member 13 includes a first shift fork ring 131, a second shift fork ring 132, and a third shift fork ring 133. The first shift fork ring 131, the second shift fork ring 132, and the third shift fork ring 133 are all axially movably sleeved on the control shaft 121, and each has a protrusion and / or a groove. The first shift fork ring 131 and the third shift fork ring 133 are located at opposite ends of the second shift fork ring 132, and are connected. The shift fork 11 is mounted on the second shift fork ring 132. The positioning member 122 is used to push the first shift fork ring 131, the second shift fork ring 132, and the third shift fork ring 133 in the same or opposite directions to drive the shift fork 11 to move axially. In this configuration, the positioning element 122 pushes the protrusion or groove of the first shift fork ring 131, causing the first shift fork ring 131 to move; the positioning element 122 pushes the protrusion or groove of the second shift fork ring 132, causing the second shift fork ring 132 to move; and the positioning element 122 pushes the protrusion or groove of the third shift fork ring 133, causing the third shift fork ring 133 to move. For example, by designing the positions of the protrusions or grooves on the first shift fork ring 131, the second shift fork ring 132, and the third shift fork ring 133, the positioning element 122 can push the first shift fork ring 131 and the third shift fork ring 133 to move in the same direction, or the positioning element 122 can push the first shift fork ring 131 and the second shift fork ring 132 to move in opposite directions. By setting multiple shift fork rings, the requirements for the shift fork 11 to move in different directions and to move different distances can be met, thereby satisfying the requirements for multiple gears in a mid-mounted transmission.

[0065] In one embodiment, the first shift fork ring 131 has a first protrusion 1311, and the second shift fork ring 132 has a second groove 1321 on one side. The first protrusion 1311 and the second groove 1321 are arranged opposite to each other. The positioning member 122 is used to sequentially abut against the first protrusion 1311 and the second groove 1321 during the rotation of the control shaft 121 to push the shift fork 11 to move to one side from the initial position, and to sequentially leave the second groove 1321 and the first protrusion 1311 during the rotation of the control shaft 121 to push the shift fork 11 back to the initial position. Specifically, during the rotation of the control shaft 121 in the first direction (clockwise or counterclockwise), the positioning member 122 first abuts against the first protrusion 1311, thereby pushing the first shift fork ring 131 to move away from the second shift fork ring 132. Since the first shift fork ring 131 and the third shift fork ring 133 are fixedly connected, the first shift fork ring 131 drives the third shift fork ring 133 to move closer to the second shift fork ring 132. Subsequently, the control shaft 121 continues to rotate, causing the positioning member 122 to abut against the second groove 1321, thereby causing the second shift fork ring 132 and the shift fork 11 to move synchronously towards the first shift fork ring 131. During the rotation of the control shaft 121 in a second direction opposite to the first direction, the positioning member 122 first leaves the second groove 1321, thereby pushing the second shift fork ring 132 and the shift fork 11 away from the first shift fork ring 131 until they return to their initial positions. Then, the control shaft 121 continues to rotate, causing the positioning member 122 to leave the first protrusion 1311, thereby causing the first shift fork ring 131 and the third shift fork ring 133 to return to their initial positions. Through the cooperation of the first shift fork ring 131 and the second shift fork ring 132, the shift fork 11 can move in opposite directions, which in turn allows the clutch 20 to move in opposite directions, realizing gear engagement and disengagement.

[0066] In one embodiment, the third shift fork ring 133 is provided with a third protrusion 1331, and the other side of the second shift fork ring 132 is provided with a fourth groove 1322. The third protrusion 1331 and the fourth groove 1322 are arranged opposite to each other. The positioning member 122 is used to sequentially abut against the third protrusion 1331 and the fourth groove 1322 during the rotation of the control shaft 121 to push the shift fork 11 from the initial position to the other side, and to sequentially leave the fourth groove 1322 and the third protrusion 1331 during the rotation of the control shaft 121 to push the shift fork 11 back to the initial position. Specifically, during the rotation of the control shaft 121 in the second direction, the positioning member 122 first abuts against the third protrusion 1331, thereby pushing the third shift fork ring 133 to move away from the second shift fork ring 132. Since the first shift fork ring 131 and the third shift fork ring 133 are fixedly connected, the third shift fork ring 133 drives the first shift fork ring 131 to move closer to the second shift fork ring 132. Subsequently, the control shaft 121 continues to rotate, causing the positioning member 122 to abut against the fourth groove 1322, thereby causing the second shift fork ring 132 and the shift fork 11 to move synchronously towards the third shift fork ring 133. During the rotation of the control shaft 121 in the first direction, the positioning member 122 first leaves the fourth groove 1322, thereby pushing the second shift fork ring 132 and the shift fork 11 to move synchronously away from the third shift fork ring 133 until they return to their initial positions. Then, the control shaft 121 continues to rotate, causing the positioning member 122 to leave the third protrusion 1331, thereby causing the third shift fork ring 133 and the first shift fork ring 131 to return to their initial positions. Through the cooperation of the third shift fork ring 133 and the second shift fork ring 132, the shift fork 11 can move in opposite directions, which in turn allows the clutch 20 to move in opposite directions, realizing gear engagement and disengagement. Through the cooperation of the first shift fork ring 131, the second shift fork ring 132, the third shift fork ring 133 and the positioning member 122, the shift fork 11 can drive the clutch 20 to engage and disengage with the components (such as gears) on both sides of the clutch 20, thereby saving the space occupied by the clutch 20.

[0067] In one embodiment, the positioning member 122 includes a first positioning pin 1221 and a second positioning pin 1222. The first positioning pin 1221 is located between the first shift fork ring 131 and the second shift fork ring 132, and the second positioning pin 1222 is located between the second shift fork ring 132 and the third shift fork ring 133. The first positioning pin 1221 is used to sequentially abut against the first protrusion 1311 and the second groove 1321 during the rotation of the control shaft 121 to push the shift fork 11 from its initial position to one side, and to sequentially disengage from the second groove 1321 and the first protrusion 1311 during the rotation of the control shaft 121 to push the shift fork 11 back to its initial position. The second positioning pin 1222 is used to sequentially abut against the third protrusion 1331 and the fourth groove 1322 during the rotation of the control shaft 121 to push the shift fork 11 from its initial position to the other side, and to sequentially disengage from the fourth groove 1322 and the third protrusion 1331 during the rotation of the control shaft 121 to push the shift fork 11 back to its initial position. The first positioning pin 1221 and the second positioning pin 1222 correspond to gear engagement and disengagement in two directions, respectively, which can more precisely control the clutch 20 to engage and disengage.

[0068] It is understood that the third shift fork ring 133 is provided with a third groove 1332 corresponding to the first protrusion 1311 on the first shift fork ring 131, so that the first positioning pin 1221 can push the first shift fork ring 131 to move while simultaneously driving the third shift fork ring 133 to move synchronously. The first shift fork ring 131 is provided with a first groove 1312 corresponding to the third protrusion 1331 on the third shift fork ring 133, so that the second positioning pin 1222 can push the third shift fork ring 133 to move while simultaneously driving the first shift fork ring 131 to move synchronously.

[0069] In one embodiment, the drive assembly 10 further includes an elastic member 14 with its two ends respectively abutting against the connector 13 and the shift fork 11. The elastic member 14 is used to be in a compressed state when the positioning member 122 pushes the connector 13, so as to push the shift fork 11 or the connector 13 to move when it returns to the normal state. This can provide a restoring force to the connector 13 when the positioning member 122 pushes the connector 13, thereby reducing the impact force when shifting or shifting gears.

[0070] In one embodiment, the connector 13 further includes a connecting post 134, which passes through the shift fork 11 and is connected at both ends to the first shift fork ring 131 and the third shift fork ring 133, thereby enabling a stable connection between the connector 13 and the shift fork 11 and improving the stability of the shift fork 11 during movement.

[0071] In one embodiment, the elastic element 14 includes a first elastic element 141 and a second elastic element 142 sleeved on the connecting post 134. The two ends of the first elastic element 141 abut against one side of the first shift fork ring 131 and the shift fork 11, respectively, and the two ends of the second elastic element 142 abut against the other side of the third shift fork ring 133 and the shift fork 11, respectively, thereby providing restoring forces to the first shift fork ring 131 and the third shift fork ring 133. The elastic element 14 is a component that undergoes elastic deformation when subjected to force and can return to its initial state after the force is reduced or eliminated. For example, the elastic element 14 is a spring.

[0072] During the rotation of the control shaft 121 in the first direction, the first positioning pin 1221 first abuts against the first protrusion 1311, thereby pushing the first shift fork ring 131 to move away from the second shift fork ring 132. Since the first shift fork ring 131 and the third shift fork ring 133 are fixedly connected, the first shift fork ring 131 drives the third shift fork ring 133 to move closer to the second shift fork ring 132. At this time, the second shift fork ring 132 remains stationary, and the third shift fork ring 133 compresses the second elastic member 142. Afterward, the control shaft 121 continues to rotate, causing the first positioning pin 1221 to abut against the second groove 1321. The second elastic member 142 pushes the shift fork 11, causing the shift fork 11 to drive the second shift fork ring 132 to move closer to the first shift fork ring 131. The second elastic member 142 then returns to its initial state. During the rotation of the control shaft 121 in the second direction, the first locating pin 1221 first disengages from the second groove 1321, thereby pushing the second shift fork ring 132 and the shift fork 11 to move synchronously away from the first shift fork ring 131. At this time, the first shift fork ring 131 and the third shift fork ring 133 remain stationary, and the shift fork 11 compresses the second elastic member 142. Afterward, the control shaft 121 continues to rotate, causing the first locating pin 1221 to disengage from the first protrusion 1311, thereby causing the second elastic member 142 to push the third shift fork ring 133 to move away from the second shift fork ring 132, simultaneously driving the first shift fork ring 131 to move closer to the second shift fork ring 132. The second elastic member 142 returns to its initial state, and the first shift fork ring 131 and the third shift fork ring 133 return to their initial positions.

[0073] Specifically, the movement of the shift fork 11 towards the second shift fork ring 132, moving it closer to the first shift fork ring 131, can enable the shift fork 11 to engage the clutch 20. This means the shift fork 11 engages the gear under the push of the second elastic element 142, thus engaging the gear through a non-rigid connection (soft connection), allowing the clutch 20 to better engage with adjacent components. Conversely, the movement of the first locating pin 1221 towards the second shift fork ring 132 and the shift fork 11, moving them synchronously away from the first shift fork ring 131, can enable the shift fork 11 to engage the clutch 20, thus disengaging the gear. This allows for disengagement through a rigid connection (i.e., the locating pin directly pushes the shift fork 11), improving the speed of disengagement.

[0074] During the rotation of the control shaft 121 in the second direction, the second positioning pin 1222 first abuts against the third protrusion 1331, thereby pushing the third shift fork ring 133 to move away from the second shift fork ring 132. Since the first shift fork ring 131 and the third shift fork ring 133 are fixedly connected, the third shift fork ring 133 drives the first shift fork ring 131 to move closer to the second shift fork ring 132. At this time, the second shift fork ring 132 remains stationary, and the first shift fork ring 131 compresses the first elastic member 141. Afterward, the control shaft 121 continues to rotate, causing the second positioning pin 1222 to abut against the fourth groove 1322. The first elastic member 141 pushes the shift fork 11, causing the shift fork 11 to drive the second shift fork ring 132 to move closer to the third shift fork ring 133. During the rotation of the control shaft 121 in the first direction, the positioning member 122 first leaves the fourth groove 1322, thereby pushing the second shift fork ring 132 to move away from the third shift fork ring 133. At this time, the first shift fork ring 131 and the third shift fork ring 133 remain stationary, and the shift fork 11 compresses the first elastic member 141. Afterward, the control shaft 121 continues to rotate, causing the positioning member 122 to leave the third protrusion 1331, thereby causing the first elastic member 141 to push the first shift fork ring 131 to move away from the second shift fork ring 132, and driving the third shift fork ring 133 to move closer to the second shift fork ring 132. The first elastic member 141 returns to its initial state, and the first shift fork ring 131 and the third shift fork ring 133 return to their initial positions.

[0075] Specifically, the movement of the shift fork 11 towards the second shift fork ring 132 and closer to the third shift fork ring 133 can drive the clutch 20 to engage gears. That is, the shift fork 11 engages gears under the push of the first elastic element 141, thus engaging gears through a non-rigid connection (soft connection), allowing the clutch 20 to better engage with adjacent components. The movement of the second locating pin 1222 towards the second shift fork ring 132 and the shift fork 11 and further away from the third shift fork ring 133 can drive the clutch 20 to disengage, thus disengaging gears through a rigid connection (i.e., directly pushing the shift fork 11), improving the speed of disengagement.

[0076] In one embodiment, one end of the first elastic member 141 abuts against one side of the shift fork 11 via a first washer 135 sleeved on the connecting post 134, thereby increasing the interaction force between the first elastic member 141 and the shift fork 11. One end of the second elastic member 142 abuts against the other side of the shift fork 11 via a second washer 136 sleeved on the connecting post 134, thereby increasing the interaction force between the second elastic member 142 and the shift fork 11.

[0077] In one embodiment, the connecting post 131 has a protrusion, and the shift fork 11 is sleeved on the protrusion. The first washer 135 abuts against one side of the protrusion, and the second washer 136 abuts against the other side of the protrusion, thereby positioning the first washer 135 and the second washer 136. Simultaneously, when the shift fork 11 is located on the protrusion, there is no interaction force between the shift fork 11 and the first elastic member 141 and the second elastic member 142. When the shift fork 11 leaves the protrusion, there is an interaction force between the first washer 135 and the first elastic member 141, or between the second washer 136 and the second elastic member 142. This ensures that the first elastic member 141 and the second elastic member 142 do not affect each other, resulting in a more balanced force distribution on the first elastic member 141 and the second elastic member 142. This allows for better design of the first elastic member 141 and the second elastic member 142 based on their respective force distribution.

[0078] In one embodiment, there are two connecting posts 134, which are located on both sides of the control shaft 121. Correspondingly, there are also two first elastic members 141 and two second elastic members 142. This allows the first shift fork ring 131 and the third shift fork ring 133 to be fixed at both ends, and the two connecting posts 134 to be respectively inserted on both sides of the shift fork 11, thereby improving the stability of the shift fork movement process.

[0079] In one embodiment, the first shift fork ring 131 has two mounting holes at both ends, each for mounting a connecting post 134. The lines connecting the centers of the two mounting holes to the center of the first shift fork ring 131 are not collinear, i.e., the two mounting holes are staggered, thereby saving axial installation space for the first shift fork ring 131. Simultaneously, the line connecting the centers of the two mounting holes passes through the center of the first shift fork ring 131, which allows for more balanced force distribution on the shift fork 11 and reduces friction between the first shift fork ring 131 and the connecting post 134 during movement. Similarly, the third shift fork ring 133 has two mounting holes at both ends. The two mounting holes of the third shift fork ring 133 have the same structure as the two mounting holes of the first shift fork ring 131, which further improves the force balance of the shift fork 11 and reduces friction between the third shift fork ring 133 and the connecting post 134 during movement.

[0080] Another embodiment of this application provides a mid-mounted transmission, such as Figures 5 to 14The mid-mounted transmission includes the aforementioned drive assembly 10, as well as a clutch 20, a main shaft 30, a countershaft 40 parallel to the main shaft 30, a transmission mechanism 50, and an output mechanism 60. The transmission mechanism 50 includes at least one main gear 51 mounted on the main shaft 30 and at least one counter gear 52 mounted on the countershaft 40. The main gears 51 and counter gears 52 are all of different dimensions. The number of main gears 51 and counter gears 52 is equal, and each main gear 51 meshes with its corresponding counter gear 52.

[0081] The clutch 20 is mounted on the main shaft 30, and the drive assembly 10 is used to drive the clutch 20 to move axially, thereby controlling each main gear 51 to lock or disengage from the main shaft 30 through the clutch 20, so as to change the transmission route between the main shaft 30 and the output mechanism 60.

[0082] Alternatively, the clutch 20 is mounted on the countershaft 40, and the drive assembly 10 is used to drive the clutch 20 to move axially, thereby controlling the locking or disengagement of each countergear 52 from the countershaft 40 through the clutch 20, so as to change the transmission route between the main shaft 30 and the output mechanism 60.

[0083] The shift fork 11 is mounted on the clutch 20. For example, the clutch 20 has an engagement groove, and the shift fork 11 is mounted on the engagement groove, so that the shift fork 11 drives the clutch 20 to move axially under the drive of the control element 12. The clutch 20 can be a dog clutch. By using the axial sliding clutch 20, the engagement and disengagement of the main gears 51 on both sides of the clutch 20 with the main shaft 30 can be controlled, or the engagement and disengagement of the secondary gears 52 on both sides of the clutch 20 with the secondary shaft 40 can be controlled, thereby reducing the number of clutches 20 and thus reducing the size of the mid-mounted transmission.

[0084] Specifically, the main shaft 30 is used to rotate under the action of external force. For example, the main shaft 30 is connected to the crank of a bicycle, and when the user pedals the bicycle, the crank drives the main shaft 30 to rotate. Alternatively, a motor provides power to the main shaft 30, driving it to rotate. Different main gears 51 are locked to the main shaft 30, or different secondary gears 52 are locked to the secondary shaft 40, forming different transmission routes. These different transmission routes transmit the driving force of the main shaft 30's rotation to the output mechanism 60. The output mechanism 60 is used to connect to the bicycle's chainring, thereby converting the driving force of the main shaft 30 into the forward propulsion of the bicycle.

[0085] Because the main gears 51 and the secondary gears 52 have different dimensions, the ratio of the input angular velocity to the output angular velocity (gear ratio) will also be different when the transmission routes between the main shaft 30 and the output mechanism 60 are different. That is, different transmission routes correspond to different gear ratios. Therefore, by driving the clutch 20 to move through the drive assembly 10, the switching of different transmission routes can be achieved, i.e., gear shifting. Using the aforementioned drive assembly 10, the forces at both ends of the shift fork 11 can be balanced, solving the cantilever problem of the shift fork 11 caused by single-end drive, allowing the shift fork 11 to move more smoothly along the axial direction, thereby improving the stability of the clutch 20 during movement. At the same time, by solving the cantilever problem of the shift fork 11, the design strength requirements for the shift fork 11 and the control component 12 can be reduced, improving the reliability of the drive assembly 10. Furthermore, by synchronously moving both ends of the shift fork 11, the driving force at each end of the shift fork 11 can be reduced to half of the driving force in single-end drive, further reducing the design strength requirements for the shift fork 11. Therefore, the shift fork 11 can operate under greater thrust, enabling the drive assembly 10 to shift gears even when the clutch 20 is under load, thus improving the user's shifting experience.

[0086] In one embodiment, each main gear 51 is fixedly mounted on the main shaft 30, and each secondary gear 52 is circumferentially rotatable and axially fixedly mounted on the secondary shaft 40; the clutch 20 is circumferentially fixed and axially movablely mounted on the secondary shaft 40, and the drive assembly 10 is used to drive the clutch 20 to move axially, so that the clutch 20 and the adjacent secondary gear 52 are axially engaged. For any secondary gear 52, when the clutch 20 and the secondary gear 52 are axially engaged, the secondary shaft 40, the clutch 20, and the secondary gear 52 are mutually locked, so that the secondary shaft 40 and the secondary gear 52 rotate synchronously; when the secondary gear 52 is not engaged with the clutch 20, the secondary shaft 40 and the secondary gear 52 do not rotate synchronously.

[0087] When one of the secondary gears 52 is locked to the secondary shaft 40, the main shaft 30 rotates under the drive of an external force, causing each main gear 51 to rotate. Each main gear 51 then drives its corresponding secondary gear 52 to rotate. The secondary gear 52 locked to the secondary shaft 40 drives the secondary shaft 40 to rotate, which in turn drives the output mechanism 60 to rotate. Therefore, different secondary gears 52 locked to the secondary shaft 40 correspond to different transmission routes, resulting in different gear ratios. In other words, gear shifting can be achieved by controlling the engagement and disengagement of the secondary gear 52 on the secondary shaft 40.

[0088] The size of the secondary gear 52 is smaller than that of the primary gear 51. Gear shifting is achieved by controlling the engagement and disengagement of the secondary gear 52 on the secondary shaft 40, which reduces the size of the shift fork 11, thereby reducing the size of the drive assembly 10 and ultimately the overall size of the mid-mounted transmission. Simultaneously, reducing the size of the shift fork 11 increases its structural strength, allowing for a reduction in its thickness and consequently, a reduction in the length of the control component 12 driving the shift fork 11. Furthermore, controlling only the secondary gear 52 on the secondary shaft 40 also reduces the number of control components 12 driving the shift fork 11.

[0089] For example, four auxiliary gears 52 and two clutches 20 are mounted on the auxiliary shaft 40. Each clutch 20 is used to control the engagement and disengagement of two adjacent auxiliary gears 52 with the auxiliary shaft 40. By switching the locking of different auxiliary gears 52 with the auxiliary shaft 40, four transmission routes can be obtained.

[0090] In one embodiment, the mid-drive transmission further includes a splined sleeve 70 fixedly mounted on the countershaft 40. The splined sleeve 70 abuts against one side of the countergear 52 to restrict the axial movement of the countergear 52. The clutch 20 is circumferentially fixed and axially movably mounted on the outside of the splined sleeve 70. By mounting the splined sleeve 70 on the countershaft 40, the clutch 20 can be circumferentially fixed while the axial movement of the countergear 52 is restricted, thereby eliminating the need for components that axially fix the countergear 52, saving installation space for the countergear 52, and consequently shortening the length of the countershaft 40.

[0091] In one embodiment, at least two splined sleeves 70 are used, and at least one splined sleeve 70 is detachably mounted on the countershaft 40. Exemplarily, there are two splined sleeves 70 and four counter-gears 52, with one counter-gear 52 mounted at each end of each splined sleeve 70, and two counter-gears 52 between two splined sleeves 70. During installation, the counter-gears 52 and splined sleeves 70 are sequentially mounted on the countershaft 40 to complete the installation, reducing assembly difficulty.

[0092] In one embodiment, the output mechanism 60 includes an output gear 61 sleeved on the main shaft 30. The output gear 61 is used to rotate under the drive of the secondary shaft 40 when one of the at least one secondary gear 52 is locked with the secondary shaft 40, and to rotate under the drive of the main shaft 30 when all secondary gears 52 are disengaged from the secondary shaft 40. When the output gear 61 rotates under the drive of the main shaft 30, the transmission route does not pass through the speed change mechanism 50, that is, the output gear 61 and the main shaft 30 rotate synchronously, and the input angular velocity and output angular velocity are the same. Therefore, the driving force of the main shaft 30 can be transmitted to the output gear 61 without speed change, meeting different user needs.

[0093] In one embodiment, the transmission mechanism 50 further includes a transmission gear 53 mounted on the countershaft 40. When the countershaft 40 rotates following the countershaft gear 52, the transmission gear 53 rotates under the drive of the countershaft 40. The transmission gear 53 meshes with the output gear 61, thereby driving the output gear 61 to rotate. Therefore, the driving force of the countershaft 40 is transmitted to the output gear 61 through the transmission gear 53.

[0094] In one embodiment, the output mechanism 60 further includes a one-way clutch assembly 62, which is used to disengage the output gear 61 from the main shaft 30 when one of the at least one of the secondary gears 52 is locked with the secondary shaft 40, thereby causing the output gear 61 to rotate under the drive of the secondary shaft 40. The one-way clutch assembly 62 is also used to lock the output gear 61 with the main shaft 30 when all the secondary gears 52 are disengaged from the secondary shaft 40, thereby causing the output gear 61 to rotate with the main shaft 30. The one-way clutch assembly 62 can be an internal gear one-way clutch, an external gear one-way clutch, or a roller one-way clutch, etc.

[0095] In one embodiment, the output gear 61 includes an output portion 611 and a clutch portion 612 protruding from the end face of the output portion 611. The clutch portion 612 extends into the main gear 51 adjacent to the output gear 61. That is, one end of the main gear 51 adjacent to the output gear 61 is fixed on the main shaft 30, and the other end is sleeved on the clutch portion 612. The clutch portion 612 is used to adapt to the one-way clutch assembly 62, thereby locking or disengaging from the main shaft 30, and thus locking or disengaging the output gear 61 from the main shaft 30. By extending the clutch portion 612 into the main gear 51 adjacent to the output gear 61, the axial space occupied by the output gear 61 can be reduced, thereby shortening the length of the main shaft 30.

[0096] In one embodiment, a one-way clutch assembly 62 is installed within the main gear 51 adjacent to the output gear 61. The outer side of the clutch portion 612 is adapted to the one-way clutch assembly 62. The one-way clutch assembly 62 allows the outer side of the clutch portion 612 to be locked or disengaged from the main gear 51. Since the main gear 51 is fixedly mounted on the main shaft 30, the one-way clutch assembly 62 can control the locking or disengagement of the clutch portion 612 from the main shaft 30. Furthermore, by placing the one-way clutch assembly 62 on the outer side of the clutch portion 612, the size of the one-way clutch assembly 62 can be increased, thereby increasing its strength and rigidity, and thus improving the stability of the mid-mounted transmission during gear shifting.

[0097] Exemplarily, the one-way clutch assembly 62 includes a retainer 621, rollers 622, and an elastic connector 624. The retainer 621 is mounted inside the main gear 51 and outside the clutch portion 612. A plurality of receiving grooves 623 are formed between the retainer 621 and the clutch portion 612. The rollers 622 are located within the receiving grooves 623. The two ends of the elastic connector 624 are connected to the clutch portion 612 and the retainer 621, respectively. The clutch portion 612 has a plurality of fifth grooves 6121 on its outer side, and each fifth groove 6121 forms a receiving groove 623 between itself and the retainer 621. When one of the secondary gears 52 is locked to the secondary shaft 40, the main shaft 30 rotates, causing the main gear 51 to rotate, which in turn causes the secondary gear 52 to rotate. The secondary gear 52 locked to the secondary shaft 40 causes the secondary shaft 40 to rotate, which in turn causes the transmission gear 53 to rotate, and the transmission gear 53 causes the output gear 61 to rotate. At this time, the rotational speed of the output gear 61 is greater than the rotational speed of the main shaft 30. The main gear 51 rotates synchronously with the main shaft 30. Therefore, the rotational speed of the clutch part 612 is greater than the rotational speed of the main gear 51. As a result, the roller 622, driven by friction, pushes the cage 621 and the clutch part 612 to move relative to each other and stretches the elastic connector 624. This causes the roller 622 to move towards the fifth groove 6121, thereby increasing the distance between the clutch part 612 and the cage 621. This causes the output gear 61 to separate from the main gear 51, and also separates the output gear 61 from the main shaft 30. Consequently, the output gear 61 rotates under the drive of the countershaft 40. When none of the secondary gears 52 are locked to the secondary shaft 40, the rotation of the secondary gears 52 cannot drive the secondary shaft 40 to rotate. The speed of the secondary shaft 40 decreases, which in turn decreases the speed of the transmission gear 53, thereby reducing the speed of the output gear 61. As the main gear 51 drives the retainer 621 to rotate, the speeds of the retainer 621 and the clutch 612 gradually approach each other until they are equal. At this time, the elastic connector 624 pulls the retainer 621 to push the roller 622 away from the fifth groove 6121, thereby making the clutch 612 and the main gear 51 engage as a whole through the roller 622. This locks the output gear 61 to the main gear 51, and also locks the output gear 61 to the main shaft 30, allowing the output gear 61 to rotate under the drive of the main shaft 30.

[0098] In another embodiment, a one-way clutch assembly 62 is mounted on the main shaft 30, and the inner side of the clutch portion 612 is adapted to the one-way clutch assembly 62. Through the one-way clutch assembly 62, the inner side of the clutch portion 612 can be locked or disengaged from the main shaft 30.

[0099] In one embodiment, the output mechanism 60 further includes a bearing member 63 rotatably mounted on the main shaft 30 in the circumferential direction, and the output part 611 is sleeved on the bearing member 63, thereby reducing the radial swing of the output gear 61 and reducing the friction between the output gear 61 and the main shaft 30, thereby improving the stability of the output mechanism 60.

[0100] In one embodiment, the output unit 611 includes a gear structure 6111 and a mounting structure 6112 connected to each other. The mounting structure 6112 is used to mount the chainring, so that the output mechanism 60 can directly drive the chainring to rotate, providing power to the bicycle with the mid-mounted derailleur.

[0101] In one embodiment, the transmission gear 53 is circumferentially rotatably mounted on the countershaft 40. The mid-drive transmission also includes a torque sensor assembly 80, which is circumferentially fixedly mounted on the countershaft 40 and connected to the transmission gear 53. The torque sensor assembly 80 can send the detected torque of the countershaft 40 rotation to the controller of the mid-drive transmission, so that the controller can determine the shift timing or detect faults in the mid-drive transmission. At the same time, by circumferentially fixing the torque sensor assembly 80 on the countershaft 40, it can also circumferentially fix the transmission gear 53, thereby eliminating the need for a fixing component for the transmission gear 53 and shortening the length of the countershaft 40.

[0102] In one embodiment, the torque sensor assembly 80 includes a sensor fixture 81, a torque measuring element, a first circuit assembly 82, and a second circuit assembly 83. The sensor fixture 81 includes a fixing part 811 circumferentially fixed on the secondary shaft 40 and a lever arm 812 protruding from the fixing part 811. The lever arm 812 is connected to the transmission gear 53. The torque measuring element is mounted on the lever arm 812. The first circuit assembly 82 is fixedly mounted on the secondary shaft 40 and is communicatively connected to the torque measuring element and the second circuit assembly 83. The second circuit assembly 83 is sleeved on the secondary shaft 40 and is rotatable relative to the first circuit assembly 82. By mounting the torque measuring element on the lever arm 812, the torque of the secondary shaft 40 can be directly detected, reducing structural complexity. The first circuit assembly 82 and the second circuit assembly 83 are rotatable relative to each other to achieve wireless communication. After receiving the torque signal collected by the torque measuring element, the first circuit assembly 82 sends the torque signal to the controller through the second circuit assembly 83. Meanwhile, the sensor fixture 81 and the transmission gear 53 are designed separately, and the lever arm 812 is connected to the transmission gear 53, which can make the force on the lever arm 812 more balanced, thereby enabling the torque measuring device to collect more accurate torque signals.

[0103] In one embodiment, the first circuit assembly 82 is fixed to the secondary shaft 40 by a fixing part 811. For example, the first circuit assembly 82 is threadedly connected to the fixing part 811, thereby reducing the number of components on the secondary shaft 40 used to fix the first circuit assembly 82 and simplifying the structure of the secondary shaft 40.

[0104] In one embodiment, the first circuit assembly 82 includes a first annular cavity 821 and a first circuit module installed within the first annular cavity 821, and the second circuit assembly 83 includes a second annular cavity 831 and a second circuit module installed within the second annular cavity 831. The first annular cavity 821 is fixedly sleeved on the sub-shaft 40, and the second annular cavity 831 is rotatably sleeved outside the first annular cavity 821, thereby reducing the space occupied by the first circuit assembly 82 and the second circuit assembly 83, and thus shortening the size of the sub-shaft 40.

[0105] In another embodiment, the first annular cavity 821 and the second annular cavity 831 can both be sleeved on the secondary shaft 40.

[0106] In one embodiment, the second annular cavity 831 is provided with a mounting hole 832 for mounting the second annular cavity 831 on the housing of the mid-mounted transmission, thereby more securely fixing the second annular cavity 831.

[0107] In one embodiment, the first circuit module includes a first processing circuit and a first coil electrically connected to each other, and the second circuit module includes a second processing circuit and a second coil electrically connected to each other. The first processing circuit is communicatively connected to a torque measuring device and is used to convert the torque signal collected by the torque measuring device into a modulation signal, and send the modulation signal to the second coil through the first coil. The second coil is used to send the modulation signal to the second processing circuit, and the second processing circuit is used to convert the modulation signal into a torque signal and send it to the controller. The second processing circuit can be electrically connected to the power supply of the mid-mounted transmission and is used to convert the obtained electrical energy into a pulse signal, and send the pulse signal to the first coil through the second coil. The first coil is also used to send the pulse signal to the first processing circuit, and the first processing circuit is also used to rectify the pulse signal to power the first circuit module. Therefore, through wireless communication between the first circuit module and the second circuit module, wireless power supply to the first circuit module and wireless transmission of the torque signal obtained by the first circuit module to the second circuit module can be realized.

[0108] In one embodiment, the first circuit module further includes an energy storage circuit electrically connected to the first processing circuit to store the electrical energy output by the first processing circuit, thereby storing excess electrical energy and charging the first circuit module.

[0109] In one embodiment, the torque measuring device includes at least one set of pressure strain gauges, each set comprising two pressure strain gauges, which are respectively mounted on two lever arms 812. For example, the sensor fixture 81 includes two lever arms 812, and the torque measuring device includes one set of pressure strain gauges, with the two strain gauges respectively attached to the two lever arms 812. As another example, the sensor fixture 81 includes four lever arms 812, and the torque measuring device includes two sets of pressure strain gauges, with the four strain gauges respectively attached to the four lever arms 812, thereby enabling the acquisition of two sets of torque signals to improve the detection accuracy of the torque signals.

[0110] In one embodiment, the transmission gear 53 is rotatably mounted on the spline sleeve 70, and the fixing part 811 is fixedly mounted on the spline sleeve 70, so that the transmission gear 53 can be fixed on the countershaft 40 through the spline sleeve 70, and installation is convenient.

[0111] In one embodiment, the transmission gear 53 is provided with a clearance hole 531, which is fitted onto the fixing part 811, thereby reducing the space occupied by the fixing part 81 and thus shortening the size of the countershaft 40.

[0112] In one embodiment, the mid-mounted derailleur also includes a motor 90 for providing driving force to the output mechanism 60, with the motor 90 and the main shaft 30 located on the same side of the shift fork 11. For example, the motor 90 drives the output gear 61 to rotate via gears, thereby providing forward power to the bicycle. Since the shift fork 11 is relatively large, placing the motor 90 and the main shaft 30 on the same side of the shift fork 11 can reduce the size of the mid-mounted derailleur.

[0113] One embodiment of this application also provides a bicycle, which includes a frame and the aforementioned mid-mounted derailleur, the mid-mounted derailleur being mounted on the frame.

[0114] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A driving component, characterized in that, The device includes a shift fork and control components mounted at both ends of the shift fork. The shift fork is used to mount the clutch of a mid-mounted transmission. The shift fork has a second mounting hole for engaging with the clutch. The control components include two control shafts, which are respectively mounted at both ends of the shift fork. By driving the two control shafts, the two ends of the shift fork move synchronously along the axial direction, thereby driving the clutch to move along the axial direction.

2. The driving component according to claim 1, characterized in that, The shift fork has a first mounting hole, which is connected to a second mounting hole. The size of the first mounting hole is larger than the outer diameter of the clutch.

3. The driving component according to claim 2, characterized in that, The thickness of the shift fork at the second mounting hole is less than the thickness of the shift fork at the first mounting hole.

4. The driving component according to claim 1, characterized in that, The control component further includes a positioning component mounted on the control shaft, and the drive assembly further includes a connector, which is axially movably mounted on the control shaft. The shift fork is mounted on the connector. The connector has a protrusion and / or a groove. The control shaft is used to abut against the protrusion and / or the groove through the positioning component during rotation to push the connector to move, thereby driving the shift fork to move axially.

5. The driving component according to claim 4, characterized in that, The connecting member includes a first shift fork ring, a second shift fork ring, and a third shift fork ring; the first shift fork ring, the second shift fork ring, and the third shift fork ring are all axially movably sleeved on the control shaft, and each has the protrusion and / or the groove. The first shift fork ring and the third shift fork ring are respectively located at both ends of the second shift fork ring, and the first shift fork ring and the third shift fork ring are connected; the shift fork is mounted on the second shift fork ring; the positioning member is used to push the first shift fork ring, the second shift fork ring, and the third shift fork ring to move in the same direction or in opposite directions by abutting against the protrusion and / or the groove.

6. The driving component according to claim 5, characterized in that, The first shift fork ring has a first protrusion, and the second shift fork ring has a second groove on one side. The positioning member is used to abut against the first protrusion and the second groove in sequence during the rotation of the control shaft to push the shift fork to move to one side from the initial position, and to leave the second groove and the first protrusion in sequence during the rotation of the control shaft to push the shift fork back to the initial position.

7. The driving component according to claim 6, characterized in that, The third shift fork ring is provided with a third protrusion, and the other side of the second shift fork ring is provided with a fourth groove. The positioning member is used to sequentially abut against the third protrusion and the fourth groove during the rotation of the control shaft to push the shift fork from the initial position to the other side, and to sequentially leave the fourth groove and the third protrusion during the rotation of the control shaft to push the shift fork back to the initial position.

8. The driving component according to claim 7, characterized in that, The positioning element includes a first positioning pin and a second positioning pin, wherein the first positioning pin is located between the first shift fork ring and the second shift fork ring, and the second positioning pin is located between the second shift fork ring and the third shift fork ring.

9. The driving component according to claim 5, characterized in that, The drive assembly further includes elastic members at both ends that abut against the connector and the shift fork, respectively. The elastic members are used to be in a compressed state when the positioning member pushes the connector, so as to push the shift fork or the connector to move when returning to the normal state.

10. The driving component according to claim 9, characterized in that, The connector also includes a connecting post, which passes through the shift fork and is connected at both ends to the first shift fork ring and the third shift fork ring, respectively.

11. The driving component according to claim 10, characterized in that, The elastic element includes a first elastic element and a second elastic element sleeved on the connecting post. The two ends of the first elastic element abut against one side of the first shift fork ring and the shift fork, respectively, and the two ends of the second elastic element abut against the other side of the third shift fork ring and the shift fork, respectively.

12. A mid-mounted transmission, characterized in that, It includes a main shaft, a secondary shaft parallel to the main shaft, a transmission mechanism, a clutch, an output mechanism, and a drive assembly as described in any one of claims 1 to 11; The speed change mechanism includes at least one main gear mounted on the main shaft and at least one secondary gear mounted on the secondary shaft, wherein each main gear meshes with a corresponding secondary gear; The clutch is mounted on the main shaft, and the drive assembly is used to drive the clutch to move axially, thereby controlling the locking or disengagement of each of the main gears from the main shaft through the clutch, so as to change the transmission route between the main shaft and the output mechanism; Alternatively, the clutch is mounted on the secondary shaft, and the drive assembly is used to drive the clutch to move axially, thereby controlling the locking or disengagement of each of the secondary gears from the secondary shaft through the clutch, so as to change the transmission route between the main shaft and the output mechanism.

13. The mid-mounted transmission according to claim 12, characterized in that, Each of the main gears is fixedly mounted on the main shaft, and each of the secondary gears is circumferentially rotatable and axially fixedly mounted on the secondary shaft; the clutch is circumferentially fixed and axially movablely mounted on the secondary shaft, and the drive assembly is used to drive the clutch to move axially so that the clutch and the adjacent secondary gear can be axially engaged.

14. The mid-mounted transmission according to claim 13, characterized in that, The output mechanism includes an output gear sleeved on the main shaft. The output gear is used to rotate under the drive of the secondary shaft when one of the at least one secondary gear is locked with the secondary shaft, and is used to rotate under the drive of the main shaft when all the secondary gears are separated from the secondary shaft.

15. The mid-mounted transmission according to claim 14, characterized in that, The output mechanism further includes a one-way clutch assembly, which is used to disengage the output gear from the main shaft when one of the at least one secondary gears is locked with the secondary shaft, and to lock the output gear with the main shaft when all the secondary gears are disengaged from the secondary shaft.

16. The mid-mounted transmission according to claim 15, characterized in that, The output gear includes an output portion and a clutch portion protruding from the end face of the output portion. The clutch portion extends into the main gear adjacent to the output gear, and the clutch portion is locked or disengaged from the main shaft by the one-way clutch assembly.

17. The mid-mounted transmission according to claim 16, characterized in that, The one-way clutch assembly is mounted in the main gear adjacent to the output gear; or, the one-way clutch assembly is mounted on the main shaft.

18. The mid-mounted transmission according to claim 14, characterized in that, The speed change mechanism also includes a transmission gear mounted on the secondary shaft, which meshes with the output gear to drive the output gear to rotate.

19. The mid-mounted transmission according to claim 18, characterized in that, The transmission gear is rotatably mounted on the countershaft, and the mid-mounted transmission also includes a torque sensor assembly that is circumferentially fixedly mounted on the countershaft and connected to the transmission gear.

20. The mid-mounted transmission according to claim 19, characterized in that, The torque sensor assembly includes a fixing component, a torque measuring component, a first circuit assembly, and a second circuit assembly. The fixing component includes a fixing part circumferentially fixed on the secondary shaft and a lever arm protruding from the fixing part. The lever arm is connected to the transmission gear. The torque measuring component is mounted on the lever arm. The first circuit assembly is fixedly mounted on the secondary shaft. The first circuit assembly is communicatively connected to the torque measuring component and the second circuit assembly. The second circuit assembly is sleeved on the secondary shaft and is rotatable relative to the first circuit assembly.

21. The mid-mounted transmission according to claim 20, characterized in that, The first circuit assembly includes a first annular cavity and a first circuit module installed in the first annular cavity; the second circuit assembly includes a second annular cavity and a second circuit module installed in the second annular cavity; the first annular cavity is fixedly sleeved on the sub-shaft, and the second annular cavity is rotatably sleeved on the outside of the first annular cavity.

22. The mid-mounted transmission according to claim 12, characterized in that, The mid-mounted transmission also includes a splined sleeve fixedly mounted on the countershaft. The splined sleeve abuts against one side of the counter gear to restrict the axial movement of the counter gear. The clutch is circumferentially fixed and axially movable, mounted on the outside of the splined sleeve.

23. The mid-mounted transmission according to claim 22, characterized in that, The number of spline sleeves is at least two, and at least one spline sleeve is detachably mounted on the countershaft.

24. The mid-mounted transmission according to claim 12, characterized in that, The mid-mounted transmission also includes a motor for providing driving force to the output mechanism, the motor and the main shaft being located on the same side of the shift fork.

25. A bicycle comprising a frame and a mid-mounted derailleur as claimed in any one of claims 12 to 24, the mid-mounted derailleur being mounted on the frame.

Images