Multi-step variable transmission mechanism

Abstract

This invention discloses a multi-speed adjustable transmission mechanism, relating to the field of electric bicycles. Key technical features include a bottom bracket, output housing, input sleeve, planetary gear assembly, and shift adjustment assembly. The transmission mechanism of this invention integrates a planetary gear assembly with three sun gears, enabling five-speed transmission. This optimizes axial dimensions, facilitates integration of the transmission mechanism into the hub motor, and increases the number of gears, thereby optimizing the riding experience. Furthermore, the first and second gears are deceleration transmissions, facilitating easy starting while riding, further enhancing the riding experience.

Description

Technical Field

[0001] This invention relates to the field of electric bicycles, and more specifically, to a multi-speed adjustable gear mechanism. Background Technology

[0002] Currently, electric bicycles generally use a mid-drive motor or a hub motor to provide electric assistance. To enable gear shifting, a gear system is typically used. The gear system can be a separate hub or integrated into the mid-drive motor or hub motor.

[0003] A Chinese patent with authorization announcement number CN102770338B discloses a gear shifting device for a transmission unit of a vehicle driven by muscle force, which uses multiple gear sets to achieve gear shifting. However, the gear shifting device in this patent has a complex structure and large axial and radial dimensions, making it impossible to integrate into a hub motor.

[0004] A Chinese patent with authorization announcement number CN213839503U discloses a gear shifting mechanism and a transmission mechanism that can achieve 7-speed adjustment. However, the hollow transmission shaft and the separate transmission gear ring and transmission output sleeve make it impossible to integrate the transmission mechanism into the hub motor.

[0005] Therefore, how to design a transmission mechanism with multiple gears that can be integrated into the hub motor is an urgent problem to be solved. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a multi-speed adjustable transmission mechanism. The transmission mechanism integrates a planetary gear assembly with three sun gears to achieve five-speed transmission. This optimizes the axial dimensions, facilitates the integration of the transmission mechanism into the hub motor, and increases the number of gears, thereby optimizing the riding experience. At the same time, the first and second gears are deceleration transmissions, which facilitates starting while riding, further optimizing the riding experience.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A multi-speed adjustable transmission mechanism includes a central shaft, an output housing, an input sleeve, a planetary gear assembly, and a shift adjustment assembly;

[0009] The planetary gear assembly includes a planet carrier, a first planet gear and a second planet gear respectively mounted on the planet carrier, a first sun gear and an input ring gear respectively meshing with the first planet gear, and a second sun gear and an output ring gear respectively meshing with the second planet gear;

[0010] The output gear ring is fixedly connected to the output housing, or a clutch assembly is provided between the output gear ring and the output housing; a clutch assembly is provided between the planetary carrier and the output housing; one end of the input gear ring extends to provide an input ring plate connected to the input sleeve;

[0011] The shift adjustment assembly includes a first pawl, a second pawl, and a limiting gear ring; the limiting gear ring is linked to the input ring plate in the circumferential direction.

[0012] In first gear, the first pawl springs up to engage with the first sun gear, making the first sun gear fixed relative to the central axis; the limiting gear ring separates from the first sun gear, and the second pawl is in a retracted state;

[0013] In second gear, the second pawl springs up to engage with the second sun gear, making the second sun gear fixed relative to the central axis; the limiting gear ring separates from the first sun gear, and the first pawl is in the spring-up state;

[0014] In the third gear, the limiting gear ring moves axially to engage with the first sun gear; both the first pawl and the second pawl are in a retracted state.

[0015] Furthermore, the shift adjustment mechanism also includes a third pawl arranged circumferentially with the second pawl;

[0016] In fourth gear, the third pawl springs up to engage with the second sun gear, making the second sun gear fixed relative to the central axis; the limiting gear engages with the first sun gear, and both the first and second pawls are in a retracted state.

[0017] Furthermore, the second planetary gear is a multi-planetary gear, which includes a planetary gear meshing with the second sun gear and a second planetary gear meshing with the output ring gear; the planetary gear assembly also includes a third sun gear meshing with the second planetary gear, and the shift adjustment assembly also includes a fourth pawl;

[0018] In the fifth gear, the fourth pawl springs up to engage with the third sun gear, making the third sun gear fixed relative to the central axis; the limiting gear engages with the first sun gear, and the first pawl, the second pawl, and the third pawl are all in a retracted state.

[0019] Furthermore, the input ring plate has a guide tooth ring that mates with the limiting tooth ring on its radially inner side; the outer wall of the limiting tooth ring has external teeth that extend axially, and the inner wall of the guide tooth ring has internal teeth that mate with the external teeth.

[0020] Furthermore, the end face of the first sun gear is provided with a first engaging tooth, and the end face of the limiting gear ring is provided with a second engaging tooth that mates with the first engaging tooth.

[0021] Furthermore, multiple pawls are respectively embedded in the central shaft; the shift adjustment assembly also includes a shift sleeve sleeved on the central shaft, and rotating the shift sleeve controls the pawls to pop up or retract.

[0022] Furthermore, the shift adjustment assembly also includes a retaining ring and an elastic element acting on the limiting gear ring; the elastic force of the elastic element causes the limiting gear ring to tend to approach the first sun gear; the retaining ring and the shift sleeve are linked in the circumferential direction, and the retaining ring can move axially relative to the shift sleeve.

[0023] A limiting groove is provided on the central shaft. The limiting groove includes a first limiting surface and a second limiting surface arranged at intervals along the axial direction, and the first limiting surface and the second limiting surface are arranged at intervals along the circumferential direction. A limiting pin is provided on the retaining ring and embedded in the limiting groove.

[0024] In first and second gear, the limiting pin contacts the first limiting surface, and the limiting gear ring separates from the first sun gear under the obstruction of the retaining ring; in third gear and higher gears, the limiting pin contacts the second limiting surface, and the limiting gear ring moves to engage with the first sun gear.

[0025] Furthermore, the central shaft is provided with an axial channel communicating with the limiting groove, and the axial channel includes an axial opening for the insertion of the limiting pin.

[0026] Furthermore, the shift adjustment assembly also includes a drive sleeve that is rolled on the central shaft, the drive sleeve and the shift sleeve being linked circumferentially, and the drive sleeve and the shift sleeve being axially connected.

[0027] Furthermore, a cable plate is fitted onto the drive sleeve, and the cable plate and the drive sleeve are flexibly connected by an elastic element.

[0028] In summary, the present invention has the following beneficial effects:

[0029] 1. The planetary gear assembly with three sun gears can achieve five-speed transmission, which optimizes the axial dimensions, makes it easier to integrate the transmission mechanism into the hub motor, and increases the number of gears, thereby optimizing the riding experience; at the same time, the first and second gears are deceleration transmissions, which makes it easier to start while riding, thus optimizing the riding experience.

[0030] 2. The input gear ring, input ring plate and guide gear ring are integrally formed. The limiting gear ring and the guide gear ring are linked in the circumferential direction, and the limiting gear ring can move axially relative to the guide gear ring. This increases the torque transmission path in the transmission mechanism, thereby increasing the number of gears. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the multi-speed adjustable transmission mechanism in the embodiment. Figure 1 ;

[0032] Figure 2 This is a schematic diagram of the multi-speed adjustable transmission mechanism in the embodiment. Figure 2 ;

[0033] Figure 3 This is a schematic diagram of the input gear ring, input ring plate, and guide gear ring in the embodiment.

[0034] Figure 4 This is a schematic diagram of the structure of multiple pawls in the embodiment. Figure 1 ;

[0035] Figure 5 This is a schematic diagram of the structure of multiple pawls in the embodiment. Figure 2 ;

[0036] Figure 6 This is a schematic diagram of the limiting groove in the embodiment;

[0037] Figure 7 This is a schematic diagram of the shift sleeve in the embodiment;

[0038] Figure 8 This is a schematic diagram of the structure of the shift sleeve and retaining ring in the embodiment;

[0039] Figure 9 This is a schematic diagram of the structure of the shift sleeve and the drive sleeve in the embodiment.

[0040] In the diagram: 1. Central shaft; 11. Limiting groove; 111. First limiting surface; 112. Second limiting surface; 113. Transition slope; 12. Axial groove; 21. Drive sleeve; 211. First locking block; 22. Shift sleeve; 221. First hole; 222. Second hole; 223. Third hole; 224. Fourth hole; 225. Positioning hole; 23. Retaining ring; 231. Second locking block; 232. Limiting pin; 24. Limiting gear ring; 241. Second engaging tooth; 25. Spring; 26. Bushing; 27. 1. Cable plate; 28. Torsion spring; 3. Input sleeve; 41. Planet carrier; 411. Planet shaft; 42. First planetary gear; 43. First planetary gear set; 44. Second planetary gear set; 45. First sun gear; 451. First engagement tooth; 46. Second sun gear; 47. Third sun gear; 48. Input gear ring; 481. Input ring plate; 482. Guide gear ring; 49. Output gear ring; 5. Clutch assembly; 61. First pawl; 62. Second pawl; 63. Third pawl; 64. Fourth pawl; 7. Output housing. Detailed Implementation

[0041] The present invention will be further described in detail below with reference to the accompanying drawings.

[0042] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention. Example

[0043] A multi-speed adjustable transmission mechanism, which can be used in a variable speed hub or integrated into a hub motor; see reference. Figures 1 to 9 It includes a central shaft 1, an output housing 7, an input sleeve 3, a planetary gear assembly, and a shift adjustment assembly; when the transmission mechanism is integrated into the hub motor, the output housing 7 is connected to the hub of the hub motor to output torque to drive the vehicle; the central shaft 1 serves as the main shaft of the hub motor or as the half shaft of the hub motor, that is, the central shaft 1 is fixed after being installed in the vehicle.

[0044] Reference Figure 1 Specifically, in this embodiment, the planetary gear assembly includes a planet carrier 41, a first planetary gear 42 and a second planetary gear respectively mounted on the planet carrier 41, a first sun gear 45 and an input ring gear 48 respectively meshing with the first planetary gear 42, and a second sun gear 46 and an output ring gear 49 respectively meshing with the second planetary gear; preferably, in this embodiment, the second planetary gear is a multi-planetary gear; specifically, in this embodiment, the second planetary gear is a dual-planetary gear, which includes a single planetary gear 43 meshing with the second sun gear 46 and a dual planetary gear 44 meshing with the output ring gear 49; a planetary shaft 41 is provided on the planet carrier 41. 1. The first planetary gear 42, the first planetary gear 43, and the second planetary gear 44 are sequentially mounted on the planetary shaft 411 along the axial direction. The first planetary gear 42 rotates independently, while the first planetary gear 43 and the second planetary gear 44 rotate synchronously after being integrally formed. The second planetary gear adopts a multi-planetary gear, which is beneficial for increasing the number of gears in the transmission mechanism. In other optional embodiments, the multi-planetary gear can also adopt a triple planetary gear or a quadruple planetary gear, etc., and the second planetary gear can also adopt a single planetary gear. There is no limitation here. In this embodiment, the planetary gear assembly uses a planet carrier to support three sets of gear assemblies, which is beneficial for optimizing the axial dimensions.

[0045] Reference Figure 1The outer wall of the output gear ring 49 is fixedly connected to the inner wall of the output housing 7, and the two are linked circumferentially, so the torque of the output gear ring 49 is directly transmitted to the output housing 7; preferably, a clutch assembly is provided between the output gear ring 49 and the output housing 7 to achieve circumferential linkage, which can reduce sliding resistance and prevent the planetary gears and sun gear from rotating during sliding; a clutch assembly 5 is provided between the planetary carrier 41 and the output housing 7, so the planetary carrier 41 and the output housing 7 are linked unidirectionally through the clutch assembly 5, and the torque of the planetary carrier 41 is transmitted to the output housing 7 through the clutch assembly 5; the input gear ring 48 is located at the outer wall of the output housing 7. An input ring plate 481 extends from one end of the output gear ring 49. The input sleeve 3 is connected to the input ring plate 481 by screws, so the torque of the input sleeve 3 is transmitted to the input gear ring 48 through the input ring plate 481. In this embodiment, the input ring plate 481 includes an axial extension and a radial extension. The axial extension is located between the input gear ring 48 and the radial extension to avoid interference between the radial extension and the planet carrier 41. The radial extension is located between the planet carrier 41 and the input sleeve 3, and the radial extension is connected to the input sleeve 3. In this embodiment, the input gear ring 48 and the input ring plate 481 are integrally formed, which helps to reduce the number of parts and facilitates assembly. In other optional embodiments, the input gear ring 48 and the input ring plate 481 can also be fixedly connected by screws or other means to transmit torque, which is not limited here.

[0046] Reference Figures 1 to 9 In this embodiment, the shift adjustment assembly includes a first pawl 61, a second pawl 62, a third pawl 63, a fourth pawl 64, a drive sleeve 21, a shift sleeve 22, a retaining ring 23, a limiting gear ring 24, a spring 25, a bushing 26, a cable plate 27, and a torsion spring 28. The first pawl 61, the second pawl 62, the third pawl 63, and the fourth pawl 64 are all embedded in the central shaft 1. The shift sleeve 22 is respectively provided with a first hole 221 that mates with the first pawl 61 and a hole 221 that mates with the second pawl. The second hole 222 mates with the third pawl 63, the third hole 223 mates with the third pawl 63, and the fourth hole 224 mates with the fourth pawl 64; the central shaft 1 is fitted with retaining rings that mate with each pawl respectively, and the elastic force of the retaining rings can make the pawl spring up through the hole; of course, if the pawl is not aligned with the hole, the pawl is pressed into the central shaft 1 by the shift sleeve 22 and is in a retracted state; wherein, the shift sleeve 22 can press the pawl into the retracted state by rotating clockwise or counterclockwise.

[0047] Reference Figures 1 to 9The first pawl 61 is opposite to the first sun gear 45. The first pawl 61 can pass through the first hole 221 and spring up to engage with the first sun gear 45, fixing the first sun gear 45 relative to the central axis 1, i.e., the first sun gear 45 cannot rotate. The second pawl 62 and the third pawl 63 are respectively opposite to the second sun gear 46, and the second pawl 62 and the third pawl 63 are staggered circumferentially. The second pawl 62 can pass through the second hole 222 and spring up to engage with the second sun gear 46, fixing the second sun gear 46 relative to the central axis 1, i.e., the second sun gear 46 cannot rotate. The third pawl 63 can pass through the third hole 222... After 3, it springs up and engages with the second sun gear 46, making the second sun gear 46 fixed relative to the central axis 1, that is, the second sun gear 46 cannot rotate; the fourth pawl 64 is opposite to the third sun gear 47, and the fourth pawl 64 can pass through the fourth hole 224 and then spring up to engage with the third sun gear 47, making the third sun gear 47 fixed relative to the central axis 1, that is, the third sun gear 47 cannot rotate; that is, in this embodiment, the first pawl 61, the second pawl 62 and the fourth pawl 64 are arranged sequentially along the axial direction, the third pawl 63 and the second pawl 62 are located in the same axial position, and the third pawl 63 and the second pawl 62 are arranged circumferentially offset.

[0048] Reference Figures 1 to 9 The shift sleeve 22 is sleeved on the central shaft 1 and can rotate around the central shaft 1. The pawls are staggered circumferentially, allowing control over the individual pawls to spring up or retract. A positioning hole 225 extending axially is provided at one end of the shift sleeve 22 near the drive sleeve 21. A first locking block 211, capable of axially engaging with the positioning hole 225, is provided on the inner wall of the drive sleeve 21. The first locking block 211 contacts the inner wall of the positioning hole 225, thereby enabling circumferential linkage between the drive sleeve 21 and the shift sleeve 22, i.e., the drive sleeve 21 can drive the shift sleeve 22 to rotate. The first locking block 211 can axially engage with the shift sleeve 22. The retaining ring 23 is fitted onto the shift sleeve 22. The inner wall of the retaining ring 23 is provided with a second locking block 231 that is embedded in the positioning hole 225. The second locking block 231 contacts the inner wall of the positioning hole 225, thereby enabling the retaining ring 23 and the shift sleeve 22 to move circumferentially, that is, the shift sleeve 22 can drive the retaining ring 23 to rotate. At the same time, in this embodiment, the retaining ring 23 can move axially relative to the shift sleeve 22, that is, the retaining ring 23 can move along the positioning hole 225. The retaining ring 23 is provided with a limiting pin 232 that passes through the second locking block 231 and extends into the shift sleeve 22.

[0049] Reference Figures 1 to 9An axially extending guide gear ring 482 is provided on the radially inner side of the input ring plate 481, and the inner sidewall of the guide gear ring 482 is provided with axially extending internal teeth; a limiting gear ring 24 is located inside the guide gear ring 482, and the outer sidewall of the limiting gear ring 24 is provided with external teeth that mate with the internal teeth; the internal teeth and external teeth mate, so that the guide gear ring 482 and the limiting gear ring 24 are linked circumferentially, and the limiting gear ring 24 can move axially relative to the guide gear ring 482; the end face of the first sun gear 45 is provided with a first engagement tooth 451, and the end face of the limiting gear ring 24 is provided with a second engagement tooth 241 that mates with the first engagement tooth 451; the limiting gear ring 24 and the first sun gear 45 include engagement and disengagement. In two states, the limiting gear ring 24 can move axially to engage with the first sun gear 45, so that the first engaging tooth 451 and the second engaging tooth 241 are engaged. In the engaged state, the limiting gear ring 24 and the first sun gear 45 are linked circumferentially. The input gear ring 48, the input ring plate 481, and the guide gear ring 482 are integrally formed. The limiting gear ring 24 and the first sun gear 45 are linked circumferentially, that is, the input gear ring 48 and the first sun gear 45 are linked circumferentially. At this time, the input gear ring 48, the first planetary gear 42, the first sun gear 45, and the planet carrier 41 form a whole. Therefore, the input torque is continued to be transmitted by the planet carrier 41, which increases the torque transmission path in the transmission mechanism, thereby increasing the number of gears.

[0050] Reference Figures 1 to 9 The retaining ring 23 is located inside the limiting gear ring 24, and the retaining ring 23 contacts the inner end face of the limiting gear ring 24; a bearing is provided between the drive sleeve 21 and the central shaft 1, and the outer wall of the drive sleeve 21 integrates a bearing embedded in the inner wall of the input sleeve 3, and the outer wall of the input sleeve 3 integrates a bearing embedded in the inner wall of the output housing 7; the bushing 26 is embedded in the input sleeve 3, and one end of the bushing 26 contacts the guide gear ring 482, and the other end contacts the outer ring of the bearing; the spring 25 is sleeved on the limiting gear ring 24, one end of the spring 25 contacts the outer end face of the limiting gear ring 24, and the other end contacts the bushing 26; the retaining ring 23 and the spring 25 are arranged on both sides of the limiting gear ring 24, and the elastic force of the spring 25 makes the limiting gear ring 24 have a tendency to move closer to the first sun gear 45, while the retaining ring 23 prevents the limiting gear ring 24 from moving closer to the first sun gear 45.

[0051] Reference Figures 1 to 9A limiting groove 11 is provided on the central shaft 1. The inner wall of the limiting groove 11 includes a first limiting surface 111, a transition inclined surface 113 connecting with the first limiting surface 111, and a second limiting surface 112 connecting with the transition inclined surface 113. The first limiting surface 111 and the second limiting surface 112 are staggered axially and circumferentially. Compared with the first limiting surface 111, the second limiting surface 112 is closer to the first sun gear 45 axially. The limiting pin 232 on the retaining ring 23 is embedded in... Within the limiting groove 11, the elastic force of the spring 25 is transmitted to the retaining ring 23 via the limiting toothed ring 24, and the limiting pin 232 contacts the first limiting surface 111, the transition inclined surface 113, or the second limiting surface 112; an axial channel 12 communicating with the limiting groove 11 is provided on the central shaft 1, and the axial channel 12 includes an axial opening for the insertion of the limiting pin 232; the limiting pin 232 is inserted into the axial channel 12 through the axial opening, and then inserted into the limiting groove 11 through the axial channel 12, which facilitates assembly.

[0052] Reference Figure 1 One end of the input sleeve 3 extends out of the output housing 7, and a sprocket is fitted on the extended end of the input sleeve 3 to receive the pedal torque; one end of the drive sleeve 21 extends out of the input sleeve 3, and a cable plate 27 is fitted on the extended end of the drive sleeve 21. The cable plate 27 and the drive sleeve 21 are flexibly connected by a torsion spring 28; the cable plate 27 is connected to the shift cable, and the cable drives the cable plate 27 to rotate. The cable plate 27 drives the drive sleeve 21 to rotate through the torsion spring 28, and the drive sleeve 21 drives the shift sleeve 22 to rotate, thereby realizing shift adjustment; the cable plate 27 and the drive sleeve 21 are flexibly connected by the torsion spring 28, which can avoid damage to components by hard shifting.

[0053] The working principle is as follows:

[0054] In first gear, the first pawl 61 springs up and engages with the first sun gear 45, fixing the first sun gear 45 in place; at this time, the limiting gear ring 24 separates from the first sun gear 45, and the remaining pawls are in a retracted state.

[0055] The torque transmission path in first gear is: input sleeve 3, input ring plate 481, input gear ring 48, first planetary gear 42, planetary carrier 41, clutch assembly 5 to output housing 7; wherein, the rotational speed of output housing 7 is less than the rotational speed of input sleeve 3, so first gear is a speed reduction transmission.

[0056] In second gear, rotating the shift sleeve 22 causes the second pawl 62 to pass through the second hole 222 and spring up to engage with the second sun gear 46, thus fixing the second sun gear 46 in place. At this time, the limiting gear ring 24 separates from the first sun gear 45, and the third pawl 63 and the fourth pawl 64 are in a retracted state. The first pawl 61 remains in a spring-up state, fixing the first sun gear 45 in place. In the transmission path of the input gear ring 48, the first sun gear 45, and the planet carrier 41, the input gear ring 48 is input and the planet carrier 41 is output. In the transmission path of the planet carrier 41, the second sun gear 46, and the output gear ring 49, the planet carrier 41 is input and the output gear ring 49 is output. Therefore, in order to stop the rotation of the first sun gear 45 and the second sun gear 46 respectively, the stopping directions of the first pawl 61 and the second pawl 62 are opposite.

[0057] The torque transmission path in second gear is: input sleeve 3, input ring plate 481, input gear ring 48, first planetary gear 42, planetary carrier 41, second planetary gear, output gear ring 49 to output housing 7; wherein, the rotational speed of output housing 7 is greater than the rotational speed of planetary carrier 41, so clutch assembly 5 is in overrunning state; the rotational speed of output housing 7 is less than the rotational speed of input sleeve 3, so second gear is still a speed reduction transmission.

[0058] In third gear, continue to rotate the shift sleeve 22. The limit pin 232 moves circumferentially to contact the second limit surface 112. After the retaining ring 23 moves axially, the limit gear ring 24 moves axially to engage with the first sun gear 45. At this time, all four pawls are pressed by the shift sleeve 22 and are in a retracted state.

[0059] The torque transmission path for the three gears is as follows: input sleeve 3, input ring plate 481, input gear ring 48 / first sun gear 45, first planet gear 42, planet carrier 41, clutch assembly 5 to output housing 7; the rotational speed of output housing 7 is equal to the rotational speed of input sleeve 3, so the three gears are constant speed transmissions.

[0060] In fourth gear, continue to rotate the shift sleeve 22 so that the third pawl 63 passes through the third hole 223 and springs up to engage with the second sun gear 46, thus fixing the second sun gear 46 in place. At this time, the limit gear ring 24 remains engaged with the first sun gear 45, and the remaining pawls are pressed down by the shift sleeve 22 and are in a retracted state.

[0061] The torque transmission path for the fourth gear is as follows: input sleeve 3, input ring plate 481, input gear ring 48 / first sun gear 45, first planet gear 42, planet carrier 41, second planet gear, output gear ring 49 to output housing 7; wherein, the rotational speed of the output housing 7 is greater than the rotational speed of the planet carrier 41, so the clutch assembly 5 is in an overrunning state; at this time, the rotational speed of the output housing 7 is greater than the rotational speed of the input sleeve 3, so the fourth gear is an acceleration transmission.

[0062] In fifth gear, continue to rotate the shift sleeve 22 so that the fourth pawl 64 passes through the fourth hole 224 and springs up to engage with the third sun gear 47, thus fixing the third sun gear in place. At this time, the limit gear ring 24 remains engaged with the first sun gear 45, and the remaining pawls are pressed down by the shift sleeve 22 and are in a retracted state.

[0063] The torque transmission path for the fifth gear is as follows: input sleeve 3, input ring plate 481, input gear ring 48 / first sun gear 45, first planet gear 42, planet carrier 41, second planet gear, output gear ring 49 to output housing 7; wherein, the rotational speed of the output housing 7 is greater than the rotational speed of the planet carrier 41, so the clutch assembly 5 is in an overrunning state; at this time, the rotational speed of the output housing 7 is greater than the rotational speed of the input sleeve 3, so the fifth gear is an acceleration transmission.

[0064] In this embodiment, the planetary gear assembly with three sun gears can achieve five-speed transmission. This optimizes the axial dimensions, facilitates the integration of the transmission mechanism into the hub motor, and increases the number of gears, thereby optimizing the riding experience. At the same time, the first and second gears are deceleration transmissions, which makes it easier to start while riding, thus optimizing the riding experience.

[0065] During installation, rotate the shift sleeve 22 on the central shaft 1 to the third gear position. At this time, all the ratchet pawls are pressed and retracted. Align the axial groove 12 on the central shaft 1 with the limiting pin 232, and then insert the central shaft 1 into the planetary gear assembly. The second locking block 231 is then axially embedded in the positioning hole 225, the limiting pin 232 is axially embedded in the axial groove 12 and the limiting groove 11, and the first locking block 211 is axially embedded in the positioning hole 225. This allows for convenient modular assembly of the gear shifting mechanism and improves production efficiency.

Claims

1. A multi-speed adjustable transmission mechanism, characterized in that, Includes a central shaft, output housing, input sleeve, planetary gear assembly, and shift adjustment assembly; The planetary gear assembly includes a planet carrier, a first planet gear and a second planet gear respectively mounted on the planet carrier, a first sun gear and an input ring gear respectively meshing with the first planet gear, and a second sun gear and an output ring gear respectively meshing with the second planet gear; The output gear ring is fixedly connected to the output housing, or a clutch assembly is provided between the output gear ring and the output housing; a clutch assembly is provided between the planetary carrier and the output housing; one end of the input gear ring extends to provide an input ring plate connected to the input sleeve; The shift adjustment assembly includes a first pawl, a second pawl, and a limiting gear ring; the limiting gear ring is linked to the input ring plate in the circumferential direction. In first gear, the first pawl springs up to engage with the first sun gear, making the first sun gear fixed relative to the central axis; the limiting gear ring separates from the first sun gear, and the second pawl is in a retracted state; In second gear, the second pawl springs up to engage with the second sun gear, making the second sun gear fixed relative to the central axis; the limiting gear ring separates from the first sun gear, and the first pawl is in the spring-up state; In the third gear, the limiting gear ring moves axially to engage with the first sun gear; both the first pawl and the second pawl are in a retracted state.

2. The multi-speed adjustable transmission mechanism according to claim 1, characterized in that: The shift adjustment assembly also includes a third pawl arranged circumferentially with the second pawl; In fourth gear, the third pawl springs up to engage with the second sun gear, making the second sun gear fixed relative to the central axis; the limiting gear engages with the first sun gear, and both the first and second pawls are in a retracted state.

3. The multi-speed adjustable transmission mechanism according to claim 2, characterized in that: The second planetary gear is a multi-planetary gear, which includes a planetary gear meshing with the second sun gear and a second planetary gear meshing with the output ring gear; the planetary gear assembly also includes a third sun gear meshing with the second planetary gear, and the shift adjustment assembly also includes a fourth pawl; In the fifth gear, the fourth pawl springs up to engage with the third sun gear, making the third sun gear fixed relative to the central axis; the limiting gear engages with the first sun gear, and the first pawl, the second pawl, and the third pawl are all in a retracted state.

4. The multi-speed adjustable transmission mechanism according to claim 1, characterized in that: The input ring plate has a guide tooth ring that mates with the limiting tooth ring on its radially inner side; the outer wall of the limiting tooth ring has external teeth that extend axially, and the inner wall of the guide tooth ring has internal teeth that mate with the external teeth.

5. The multi-speed adjustable transmission mechanism according to claim 1, characterized in that: The end face of the first sun gear is provided with a first engaging tooth, and the end face of the limiting gear ring is provided with a second engaging tooth that mates with the first engaging tooth.

6. The multi-speed adjustable transmission mechanism according to claim 1, characterized in that: Multiple pawls are respectively embedded in the central shaft; the shift adjustment assembly also includes a shift sleeve sleeved on the central shaft, and rotating the shift sleeve controls the pawls to spring up or retract.

7. The multi-speed adjustable transmission mechanism according to claim 6, characterized in that: The shift adjustment assembly also includes a retaining ring and an elastic element acting on the limiting gear ring; the elastic force of the elastic element causes the limiting gear ring to tend to approach the first sun gear; the retaining ring and the shift sleeve are linked in the circumferential direction, and the retaining ring can move axially relative to the shift sleeve. A limiting groove is provided on the central shaft. The limiting groove includes a first limiting surface and a second limiting surface arranged at intervals along the axial direction, and the first limiting surface and the second limiting surface are arranged at intervals along the circumferential direction. A limiting pin is provided on the retaining ring and embedded in the limiting groove. In first and second gear, the limiting pin contacts the first limiting surface, and the limiting gear ring separates from the first sun gear under the obstruction of the retaining ring; in third gear and higher gears, the limiting pin contacts the second limiting surface, and the limiting gear ring moves to engage with the first sun gear.

8. The multi-speed adjustable transmission mechanism according to claim 7, characterized in that: An axial channel communicating with a limiting groove is provided on the central shaft, and the axial channel includes an axial opening for the insertion of a limiting pin.

9. The multi-speed adjustable transmission mechanism according to claim 6, characterized in that: The shift adjustment assembly also includes a drive sleeve that is rolled on the central shaft. The drive sleeve and the shift sleeve are linked circumferentially, and the drive sleeve and the shift sleeve are axially connected.

10. The multi-speed adjustable transmission mechanism according to claim 9, characterized in that: A cable plate is fitted onto the drive sleeve, and the cable plate and the drive sleeve are flexibly connected by an elastic element.

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