A three-speed gear shift mechanism and an in-wheel motor

Abstract

This invention discloses a three-speed gear mechanism and its hub motor, including a motor shaft, an electric shifting mechanism, a three-planetary gear transmission assembly, and power input and output mechanisms. The power input mechanism includes an input sleeve and an input clutch mounted on the motor shaft. The three-planetary gear transmission assembly includes a rotating planetary carrier and multiple planetary gears on it, each including first, second, and third planetary gears with progressively increasing outer diameters. It also includes first, second, and third sun gears mounted on the motor shaft and meshing with them respectively. The first sun gear is connected to the input sleeve via the input clutch. The locking mechanism of the electric shifting mechanism has two positions for locking the second and third sun gears respectively. The power output mechanism includes an output clutch and an output housing. The input sleeve is connected to the rotating planetary carrier via the output clutch, and the rotating planetary carrier is fixed to the output housing. Compared with conventional technology, this invention has a more compact structure, smaller radial dimensions, and a larger speed ratio.

Description

Technical Field

[0001] This invention relates to a three-speed gear mechanism and its hub motor. Background Technology

[0002] Traditional electric bicycles separate the hub motor and gear mechanism, with the entire gear mechanism housed on the motor shaft outside the hub housing. This design is cumbersome and bulky, taking up significant space in the frame. To simplify the structure and assembly, hub motors (internal derailleur hubs) now exist on the market, where the gear mechanism is located inside the hub housing. The axial configuration inside the hub housing typically consists of the motor core, planetary reduction gear mechanism, and gear mechanism arranged sequentially along the motor shaft.

[0003] The rotor of the mechanism serves as the output end, and a sun gear from a planetary reduction mechanism is fixed to it. This sun gear meshes with an internal gear ring on the inner circumference of the hub housing via several planetary gears in the planetary reduction mechanism. This planetary reduction mechanism uses a clutch as the planetary support, with the planetary shafts of each planetary gear fixed to the outer ring of the clutch, while the inner ring of the clutch is fixed to the motor shaft. The speed-changing gear mechanism includes a complete set of planetary gear transmission mechanisms. The input end of this mechanism has a sun gear, which is typically connected to a drive wheel mounting sleeve (such as a freehub base, used to mount the sprocket connected to the chain and the chain on the bottom shaft) on the motor shaft outside the hub housing. The planetary gears on the planetary carrier often serve as the output end and need to be connected and assembled to the inner side of the end cover of the hub housing. For example, the invention patent application CN116476968A discloses an internal speed-changing hub with a built-in motor, which belongs to this type of hub motor using an internal speed-changing gear mechanism.

[0004] However, existing transmission gear mechanisms still suffer from large radial dimensions and non-compact structures in practical applications. Especially when installed inside the hub motor housing, the overall size of the hub motor also increases, hindering space-saving design and complicating the assembly and design of other components. Our analysis suggests this is due to the overly complex output structure of current transmission gear mechanisms. They employ two parallel output mechanisms assembled with the hub housing. This requires an additional gear ring inside the hub housing to mesh with the planetary gears, and a double-layered clutch on top of the planetary carrier to connect to the hub housing. This results in an overly redundant and cumbersome structure, making assembly tedious and hindering the reduction of the radial dimensions of both the transmission gear mechanism itself and the hub motor it is fitted with.

[0005] Furthermore, existing gear transmission mechanisms, due to their complex structure and the limitation of radial dimensions of the gear components, cannot achieve a larger speed ratio.

[0006] Therefore, the industry urgently needs a transmission gear mechanism and its hub motor with a more compact design, smaller radial dimensions, and larger speed ratio. Summary of the Invention

[0007] The purpose of this invention is to provide a three-speed gear mechanism with a more compact structure, smaller radial dimensions, and a larger speed ratio.

[0008] The technical solution of the present invention is: a three-speed gear mechanism, comprising a motor shaft, an electric shifting mechanism, a three-link planetary gear transmission group, a power input mechanism, and a power output mechanism, characterized in that: the power input mechanism includes an input shaft sleeve and an input clutch disposed on the motor shaft; The triple planetary gear transmission assembly includes multiple triple planetary gears rotatably mounted on a rotating planetary carrier. Each triple planetary gear includes a first planetary gear, a second planetary gear, and a third planetary gear with progressively increasing outer diameters. It also includes a first sun gear, a second sun gear, and a third sun gear respectively meshing with each of them and mounted on the motor shaft. The first sun gear is connected to the input shaft sleeve via an input clutch. The electric shifting mechanism includes a locking mechanism driven by an electric drive device. The locking mechanism has two positions for locking the second sun gear and the third sun gear, respectively. The power take-off mechanism includes an output clutch and an output housing. The input shaft sleeve is connected to the rotating planetary carrier via the output clutch, while the rotating planetary carrier is fixed to the output housing.

[0009] Furthermore, the locking mechanism described in this invention includes a speed shift lever sleeved on the outer periphery of the motor shaft, a first pawl ring fixed to the second sun gear, and a second pawl ring fixed to the third sun gear; the inner circumference of the first pawl ring is provided with a first elastic pawl, while the inner circumference of the second pawl ring is provided with a second elastic pawl. The outer periphery of the motor shaft is provided with a first stop step portion corresponding to the first elastic pawl and a second stop step portion corresponding to the second elastic pawl in the radial direction; The gear shift lever includes several ring ribs surrounding the motor shaft, a first blocking block fixed to the ring ribs and engaging with the first stop step, and a second blocking block engaging with the second stop step. The gear shift lever is driven to rotate around the motor shaft via the electric drive device and has three working positions: In the first working position, the first blocking block is engaged with the first stop step, and the second blocking block is engaged with the second stop step, and both the second sun gear and the third sun gear can rotate freely; In the second working position, the second blocking block disengages from the second stop step and engages to create a gap that allows the second elastic pawl to engage and lock, thereby stopping the rotation of the third sun gear. Meanwhile, the first blocking block disengages from the first stop step, creating a gap that prevents the first elastic pawl from engaging. In the third working position, the first blocking block further disengages from the first stop step and cooperates to create a gap that allows the first elastic pawl to engage and lock, thereby stopping the rotation of the second sun gear. Meanwhile, the second blocking block further disengages from the second stop step, increasing the gap to the point where the second elastic pawl can no longer be locked, allowing the third sun gear to rotate freely.

[0010] Furthermore, the input clutch described in this invention is a ratchet-pawl type one-way clutch, wherein the input ratchet is fixed on the inner circumference of the input shaft sleeve, and the input pawl is disposed on the input pawl seat fixed to the first sun gear.

[0011] Furthermore, the output clutch described in this invention is a roller clutch, which includes an outer ring and an inner ring, wherein the inner ring is fixed on the input shaft sleeve, and the rotating planetary carrier is fixed to the outer ring.

[0012] Furthermore, in this invention, when both the second and third sun gears are in a free state, the transmission ratio i1 of the three-speed gear mechanism is 1. When the third sun gear is locked by the locking mechanism and the second sun gear is in a free state, the transmission ratio i2 of the three-speed gear mechanism is 1 / (1-Zb3×Zb1 / Za1×Zb3), where Zb3 is the number of teeth of the third sun gear, Zb1 is the number of teeth of the first planetary gear, Za1 is the number of teeth of the first sun gear, and Zb3 is the number of teeth of the third planetary gear.

[0013] When the second sun gear is locked by the locking mechanism and the third sun gear is in a free state, the transmission ratio i3 of the three-speed gear mechanism is 1 / (1-Za2×Zb1 / Za1×Zb2), where Za2 is the number of teeth of the second sun gear, Zb1 is the number of teeth of the first planetary gear, and Zb2 is the number of teeth of the second planetary gear.

[0014] Another object of the present invention is to provide a hub motor, characterized by employing the aforementioned three-speed gear mechanism.

[0015] Furthermore, this hub motor includes a hub housing that is fixed to or integrally formed with the output housing, and a core mechanism, a core planetary reduction mechanism, a core clutch, the three-link planetary gear transmission group, and the power input mechanism are sequentially assembled along the motor shaft inside the hub housing.

[0016] Furthermore, the hub housing is fixed by a hub ring and an end cap, the planetary carrier is fixed to the end cap, the first sun gear is supported on the motor shaft via a gear bearing, the inner circumference of the input shaft sleeve is supported on the motor shaft via a shaft sleeve bearing, and the inner side of the end cap is supported on the periphery of the input shaft sleeve via a hub bearing.

[0017] Furthermore, the movement output planetary reduction mechanism includes a fourth sun gear connected to the movement and several double planetary gears rotatably mounted on the movement output planetary carrier. Each double planetary gear includes a fourth planetary gear and a fifth planetary gear with progressively increasing outer diameters. The fifth planetary gear meshes with the fourth sun gear. The movement clutch includes an inner ring fixed to the rotating planetary carrier and an outer ring that meshes with it. An internal gear ring for movement output is fixed on the outer ring and meshes with the fourth planetary gear.

[0018] The speed-changing working principle of the hub motor with the three-speed gear mechanism described above is as follows: It has three gears: In first gear, the shift lever is in the first working position, and both the second and third sun gears are in a free state. The input bushing directly drives the rotating planetary carrier and the hub housing to rotate together via the output clutch. After the planetary carrier rotates, the three planetary gears on it also rotate. At this time, the second and third sun gears are idling. The input torque is transmitted from the input bushing to the rotating planetary carrier through the output clutch, and then to the hub housing, thereby driving the wheels of the electric bicycle to rotate. At this time, the transmission ratio i1 of the three-speed gear mechanism is 1. In second gear, the electric drive unit of the electric shift mechanism drives the locking mechanism, rotating the shift lever to the second working position, thereby locking the third sun gear, while the second sun gear is in a free state. The input bushing, via the input clutch, drives the first sun gear to rotate, causing the three-planetary gear set to mesh and rotate. The third sun gear stops, the second sun gear idles, and the entire planetary carrier rotates. Since the planetary carrier's speed is higher than the input bushing's speed, meaning the outer ring of the output clutch rotates faster than its inner ring, the output clutch is disengaged.

[0019] The input torque is transmitted from the input shaft sleeve to the first sun gear via the input clutch, then to the rotating planetary carrier via the three-planetary gear set, and finally to the hub housing, thereby driving the electric bicycle wheel to rotate. The output clutch is in the disengaged state. At this time, the transmission ratio i2 of the three-speed gear mechanism is i2 = 1 / (1 - Za3 × Zb1 / Za1 × Zb3), where Za3 is the number of teeth on the third sun gear, Zb1 is the number of teeth on the first planetary gear, and Zb3 is the number of teeth on the third planetary gear.

[0020] In third gear, the electric drive unit of the electric shift mechanism drives the locking mechanism, and the shift lever continues to rotate to the third working position, thereby locking the second sun gear, while the third sun gear is in a free state. After the input bushing drives the first sun gear to rotate via the input clutch, the three planetary gears also mesh and rotate, while the second sun gear stops, and the third sun gear idles (reversing the rotation compared to second gear). The entire planetary carrier also rotates. Since the rotational speed of the planetary carrier is higher than that of the input bushing at this time, that is, the outer ring speed of the output clutch is higher than that of its inner ring, the output clutch is in a disengaged state.

[0021] The input torque is transmitted from the input shaft sleeve to the first sun gear via the input clutch, then to the rotating planetary carrier via the three-planetary gear set, and finally to the hub housing, thereby driving the electric bicycle wheel to rotate. The output clutch is in the disengaged state. The transmission ratio of this three-speed gear mechanism is i3 = 1 / (1-Za2×Zb1 / Za1×Zb2), where Za2 is the number of teeth on the second sun gear, Zb1 is the number of teeth on the first planetary gear, and Zb2 is the number of teeth on the second planetary gear.

[0022] The advantages of this invention are: 1. The present invention provides a three-speed gear mechanism, which optimizes the structure by eliminating the original two sets of output mechanisms and adopting a single output mechanism. The single output mechanism uses a single output clutch with the outer ring fixed to the rotating planetary carrier, instead of a double-layered clutch. This not only makes the overall structure of the mechanism simpler, more compact, and easier to assemble than conventional technologies, but also, when applied to a hub motor, the rotating planetary carrier is directly fixed to the hub housing to transmit output torque. There is no need to add a gear ring and three planetary gears on the inner circumferential wall of the hub housing for meshing. This allows the radial dimension of the hub motor to be effectively reduced, and also eliminates redundant and complex structural connections, simplifying assembly. This effectively saves frame space and facilitates the assembly and design of other components on the frame.

[0023] 2. The three-speed gear mechanism and hub motor provided by the present invention can achieve a larger speed ratio compared with conventional technology due to the optimized transmission structure.

[0024] 3. The locking mechanism in this invention has a simple and compact structure, short stroke, fast execution response and high efficiency, which can improve the smoothness and reliability of speed change, and at the same time help to further reduce the overall volume of the three-speed gear mechanism and save internal space of the hub motor.

[0025] 4. Compared with the prior art, the hub motor of the present invention has a structural design in which the planetary reduction mechanism and the three-speed gear mechanism are both located on the outside of the rotor end of the mechanism. The rotor can isolate the gear lubricating grease in the planetary reduction mechanism and the three-speed gear mechanism, thereby more effectively protecting the inside of the mechanism from lubricating grease contamination. Attached Figure Description

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 A cross-sectional view of the overall structure of a hub motor using a three-speed gear mechanism; Figure 2 for Figure 1 3D exploded view of the hub motor; Figure 3 for Figure 1 A schematic diagram of the separation structure of the speed shift lever and the motor shaft in the central locking mechanism; Figure 4 for Figure 1 A three-dimensional structural diagram of the central locking mechanism (direction E is the axial view from the movement side towards the third sun gear). Figure 5 for Figure 4 Another perspective of the three-dimensional structure (F-direction is the axial view from the input shaft sleeve side to the second sun gear); Figure 6 This is a power transmission route diagram for the first gear of a three-speed geared transmission mechanism. Figure 7 This is a cross-sectional view along direction E showing the engagement state of the second elastic pawl in the second pawl ring of the locking mechanism with the gear shift lever when the three-speed gear mechanism is in first gear. Figure 8 The F-direction cross-sectional view of the first elastic pawl in the first pawl ring of the locking mechanism in the first gear of the three-speed gear transmission mechanism in the first gear and the gear shift lever in the engagement state. Figure 9 This is a diagram showing the engagement state of the shift lever and the motor shaft in the first gear of a three-speed gear mechanism (first working position). Figure 10 This is a power transmission route diagram for the second gear of a three-speed geared transmission mechanism. Figure 11 This is a cross-sectional view along direction E showing the engagement state of the second elastic pawl in the second pawl ring of the locking mechanism with the gear shift lever when the three-speed gear mechanism is in second gear. Figure 12 This is a cross-sectional view along the F direction of the locking mechanism in the second gear of a three-speed gear transmission, showing the engagement state of the first elastic pawl in the first pawl ring of the locking mechanism with the gear shift lever. Figure 13This is a diagram showing the engagement state of the shift lever and the motor shaft in the second gear of a three-speed gear mechanism (second working position). Figure 14 This is a power transmission route diagram for the third gear of a three-speed geared transmission mechanism. Figure 15 This is a cross-sectional view along direction E showing the engagement state of the second elastic pawl in the second pawl ring of the locking mechanism with the shift lever when the three-speed gear mechanism is in third gear. Figure 16 This is a cross-sectional view along the F direction of the locking mechanism in the third gear of a three-speed gear transmission, showing the engagement state of the first elastic pawl in the first pawl ring of the locking mechanism with the gear shift lever. Figure 17 This is a diagram showing the engagement state of the shift lever and the motor shaft in the third gear of a three-speed gear mechanism (third working position).

[0027] Wherein: 1. Motor shaft; 101. First stop step; 102. Second stop step; 2. Input shaft sleeve; 3. Input clutch; 301. Input ratchet; 302. Input pawl; 303. Input pawl seat; 4. Rotating planetary carrier; 5. Electric drive device; 6. Output clutch; 7. Gear shift lever; 701. Ring rib; 702. First blocking block; 703. Second blocking block; 8. First pawl ring; 9. Second pawl ring; 10. First elastic pawl; 11. Second elastic pawl; 12. Wheel Hub housing; 12a, hub ring; 12b, end cap; 13, movement; 14, movement clutch; 15, gear bearing; 16, bushing bearing; 17, hub bearing; 18, movement output planetary carrier; 19, movement output internal gear ring; 20, flywheel; a1, first sun gear; a2, second sun gear; a3, third sun gear; a4, fourth sun gear; b1, first planetary gear; b2, second planetary gear; b3, third planetary gear; b4, fourth planetary gear; b5, fifth planetary gear. Detailed Implementation

[0028] Example 1: Let's first combine... Figures 1-17 The following describes a specific application example of the present invention, which is a hub motor equipped with a three-speed gear mechanism.

[0029] Firstly, as Figure 1 and Figure 2 As shown, this hub motor has a hub housing 12 mounted on the motor shaft 1. The hub housing 12 is fixed by a hub ring 12a and an end cap 12b. Inside the hub housing 12, along the motor shaft 1, a core mechanism 13, a core planetary reduction mechanism, a core clutch 14, and a three-speed gear mechanism are sequentially mounted. The three-speed gear mechanism is the core design mechanism of this invention, and will be described in detail below.

[0030] The three-speed transmission gear mechanism in this embodiment is specifically composed of a motor shaft 1, an electric shifting mechanism, a three-link planetary gear transmission group, a power input mechanism, and a power output mechanism. The power input mechanism consists of an input bushing 2 and an input clutch 3. The input bushing 2 is supported on the motor shaft 1 via two bushing bearings 16. As with conventional technology, one end of it extends through a shaft hole on the end cover 12b to fix the flywheel 20. Figure 1 As shown, the inner side of the end cap 2b is supported on the periphery of the input shaft sleeve 2 via the hub bearing 17.

[0031] The triple planetary gear transmission assembly includes three triple planetary gears rotatably mounted on a rotating planetary carrier 4. Each triple planetary gear assembly includes a first planetary gear b1, a second planetary gear b2, and a third planetary gear b3 with progressively increasing outer diameters. It also includes a first sun gear a1, a second sun gear a2, and a third sun gear a3, which mesh with the three planetary gears respectively and are mounted on the motor shaft 1. The first sun gear a1 is connected to the input shaft sleeve 2 via an input clutch 3. (Specific details omitted) Figure 2 As shown, the input clutch 3 is a ratchet-pawl type one-way clutch. Its input ratchet 301 is fixed to the inner circumference of the input shaft sleeve 2, while the input pawl 302 is mounted on the input pawl seat 303, which is fixed to the first sun gear a1. And as before... Figure 1 As shown, in this embodiment, the first sun gear a1 is supported on the motor shaft 1 via a gear bearing 15.

[0032] In this embodiment, the electric shifting mechanism includes a locking mechanism driven by an electric drive device 5. The locking mechanism has two positions, which are used to lock the second sun gear a2 and the third sun gear a3, respectively.

[0033] The power output mechanism includes an output clutch 6 and a hub housing 12, which serves as the output housing. The input shaft sleeve 2 is connected to the rotating planetary carrier 4 via the output clutch 6, as shown below. Figure 1 As shown, the output clutch 6 in this embodiment is a roller clutch, which includes an outer ring and an inner ring. The inner ring is fixed on the input shaft sleeve 2. The rotating planetary carrier 4 is fixed to the outer ring by screws, and the rotating planetary carrier 4 is then fixed to the end cover 12b of the hub housing 12 by screws.

[0034] Further integration Figures 2-5 As shown, the locking mechanism in this embodiment includes a speed-changing lever 7 sleeved on the outer periphery of the motor shaft 1, a first pawl ring 8 fixed to the second sun gear a2, and a second pawl ring 9 fixed to the third sun gear a3; a first elastic pawl 10 is distributed on the inner circumference of the first pawl ring 8, and a second elastic pawl 11 is distributed on the inner circumference of the second pawl ring 9; the electric drive device 5 uses a stepper motor output end connected to the speed-changing lever 7 via a shift fork.

[0035] The outer periphery of the motor shaft 1 is provided with a first stop step portion 101 corresponding to the first elastic pawl 10 and a second stop step portion 102 corresponding to the second elastic pawl 11 in the radial direction. The gear shift lever 7 includes several ring ribs 701 that are sleeved around the motor shaft 1, and a first blocking block 702 that is fixed to the ring ribs 701 and engages with the first stop step 101, and a second blocking block 703 that engages with the second stop step 102. The gear shift lever 7 is driven to rotate around the motor shaft 1 via the electric drive device 5 and has the following characteristics: Figure 9 , Figure 13 and Figure 17 Three work locations: In the first working position, the first blocking block 702 engages with the first stop step 101, and the second blocking block 703 engages with the second stop step 102, allowing both the second sun gear a2 and the third sun gear a3 to rotate freely. In the second working position, the second blocking block 703 disengages from the second stop step 102 and engages to create a gap into which the second elastic pawl 11 can engage and lock, thus preventing the third sun gear a3 from rotating. Meanwhile, the first blocking block 702 disengages from the first stop step 101, creating a gap into which the first elastic pawl 10 cannot engage. Figure 11 and Figure 12 As shown; in the third working position, the first blocking block 702 further disengages from and engages with the first stop step 101 to create a gap into which the first elastic pawl 10 can engage and lock, thereby stopping the rotation of the second sun gear a2. Meanwhile, the second blocking block 703 further disengages from the second stop step 102, increasing the gap to the point where the second elastic pawl 11 can no longer be locked, allowing the third sun gear a3 to rotate freely. Figure 15 and Figure 16 As shown.

[0036] Still as Figure 1 As shown, the movement output planetary reduction mechanism includes a fourth sun gear a4 fixed to the rotor of the movement 13 and several double planetary gears rotatably mounted on the movement output planetary carrier 18. Each double planetary gear includes a fourth planetary gear b4 and a fifth planetary gear b5 with progressively increasing outer diameters. The fifth planetary gear b5 meshes with the fourth sun gear a4. The movement clutch 14 includes an inner ring fixed to the rotating planetary carrier 4 and an outer ring that meshes with it. The outer ring has a movement output internal gear ring 19 fixed on it, which meshes with the fourth planetary gear b4.

[0037] The speed-changing working principle of the hub motor with the three-speed gear mechanism described above is as follows: Combination Figures 9-17 As shown, it has three gear positions: In first gear, the shift lever 7 is in the first working position, and both the second sun gear a2 and the third sun gear a3 are in a free state. The input sleeve 2 directly drives the rotating planetary carrier 4 and the hub housing 12 to rotate together via the output clutch 6. After the rotating planetary carrier 4 rotates, the three planetary gears on it also rotate. At this time, the second sun gear a2 and the third sun gear a3 are idling. The input torque is transmitted from the input sleeve 2 to the rotating planetary carrier 4 through the output clutch 6, and then to the hub housing 12, thereby driving the wheels of the electric bicycle to rotate. At this time, the transmission ratio i1 of the three-speed gear mechanism is 1. Figure 6 As shown; In second gear, the electric drive unit of the electric shift mechanism 5 drives the locking mechanism, and the shift lever 7 rotates to the second working position, thereby locking the third sun gear a3, while the second sun gear a2 is in a free state. After the input bushing 2 drives the first sun gear a1 to rotate via the input clutch 3, the three-planetary gear also meshes and rotates, while the third sun gear a3 stops, and the second sun gear a2 idles. The entire rotating planetary carrier 4 also rotates. Since the rotational speed of the planetary carrier 4 is higher than the rotational speed of the input bushing 2 at this time, that is, the outer ring speed of the output clutch 6 is higher than the inner ring speed, the output clutch 6 is in a disengaged state.

[0038] The input torque is transmitted from the input sleeve 2 to the first sun gear a1 via the input clutch 3, then to the rotating planetary carrier 4 via the three-planetary gear set, and finally to the hub housing 12, thereby driving the electric bicycle wheel to rotate. The output clutch 6 is in the disengaged state. At this time, the transmission ratio i2 of the three-speed gear mechanism is 1 / (1-Za3×Zb1 / Za1×Zb3), where Za3 is the number of teeth of the third sun gear a3, Zb1 is the number of teeth of the first planetary gear b1, and Zb3 is the number of teeth of the third planetary gear b3.

[0039] In third gear, the electric drive unit of the electric shift mechanism drives the locking mechanism, and the shift lever 7 continues to rotate to the third working position, thereby locking the second sun gear a2, while the third sun gear a3 is in a free state. After the input bushing 2 drives the first sun gear a1 to rotate via the input clutch 3, the three planetary gears also mesh and rotate, while the second sun gear a2 stops, and the third sun gear a3 idles (reverse from the second gear). The entire rotating planet carrier 4 also rotates. Since the rotational speed of the planet carrier 4 is higher than that of the input bushing 2 at this time, that is, the outer ring speed of the output clutch 6 is higher than that of its inner ring speed, the output clutch 6 is in a disengaged state.

[0040] The input torque is transmitted from the input sleeve 2 to the first sun gear a1 via the input clutch 3, then to the rotating planetary carrier 4 via the three-planetary gear set, and finally to the hub housing 12, thereby driving the electric bicycle wheel to rotate. The output clutch 6 is in the disengaged state. The transmission ratio i3 of this three-speed gear mechanism is 1 / (1-Za2×Zb1 / Za1×Zb2), where Za2 is the number of teeth of the second sun gear a2, Zb1 is the number of teeth of the first planetary gear b1, and Zb2 is the number of teeth of the second planetary gear b2.

[0041] Of course, the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All modifications made according to the spirit and essence of the main technical solution of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A three-speed gear mechanism, comprising a motor shaft (1), an electric shifting mechanism, a three-link planetary gear transmission group, a power input mechanism, and a power output mechanism, characterized in that: The power input mechanism includes an input shaft sleeve (2) and an input clutch (3) mounted on the motor shaft (1). The triple planetary gear transmission assembly includes multiple triple planetary gears rotatably mounted on a rotating planetary carrier (4). Each triple planetary gear includes a first planetary gear (b1), a second planetary gear (b2), and a third planetary gear (b3) with progressively increasing outer diameters. It also includes a first sun gear (a1), a second sun gear (a2), and a third sun gear (a3) ​​meshing with each other on a motor shaft (1). The first sun gear (a1) is connected to the input shaft sleeve (2) via an input clutch (3). The electric shifting mechanism includes a locking mechanism driven by an electric drive device (5). The locking mechanism has two positions for locking the second sun gear (a2) and the third sun gear (a3), respectively. The power output mechanism includes an output clutch (6) and an output housing. The input shaft sleeve (2) is connected to the rotating planetary carrier (4) via the output clutch (6), while the rotating planetary carrier (4) is fixed to the output housing.

2. The three-speed gear mechanism according to claim 1, characterized in that... The locking mechanism includes a speed shift lever (7) sleeved on the outer periphery of the motor shaft (1), a first pawl ring (8) fixed to the second sun gear (a2), and a second pawl ring (9) fixed to the third sun gear (a3); the first pawl ring (8) has a first elastic pawl (10) distributed on its inner circumference, while the second pawl ring (9) has a second elastic pawl (11) distributed on its inner circumference. The outer periphery of the motor shaft (1) is provided with a first stop step (101) corresponding to the first elastic pawl (10) and a second stop step (102) corresponding to the second elastic pawl (11) in the radial direction. The gear shift lever (7) includes several ring ribs (701) sleeved around the motor shaft (1), and a first blocking block (702) fixed to the ring ribs (701) and assembled with the first stop step (101), and a second blocking block (703) assembled with the second stop step (102). The gear shift lever (7) is driven to rotate around the motor shaft (1) via the electric drive device (5) and has three working positions: In the first working position, the first blocking block (702) is engaged with the first stop step (101), and the second blocking block (703) is engaged with the second stop step (102). The second sun gear (a2) and the third sun gear (a3) ​​can rotate freely. In the second working position, the second blocking block (703) disengages from and engages with the second stop step (102) to create a gap into which the second elastic pawl (11) can be engaged and secured, thereby stopping the rotation of the third sun gear (a3), while the first blocking block (702) disengages from the first stop step (101) to create a gap into which the first elastic pawl (10) cannot be engaged. In the third working position, the first blocking block (702) and the first stop step (101) further disengage and cooperate to create a gap in which the first elastic pawl (10) can be engaged and secured, thereby stopping the second sun gear (a2) from rotating. Meanwhile, the second blocking block (703) and the second stop step (102) further disengage, causing the gap to increase to the point that the second elastic pawl (11) cannot be secured, allowing the third sun gear (a3) ​​to rotate freely.

3. A three-speed gear mechanism according to claim 1, characterized in that... The input clutch (3) is a ratchet and pawl type one-way clutch. Its input ratchet (301) is fixed on the inner circumference of the input shaft sleeve (2), while the input pawl (302) is set on the input pawl seat (303) which is fixed to the first sun gear (a1).

4. A three-speed gear mechanism according to claim 1, characterized in that... The output clutch (6) is a roller clutch, which includes an outer ring and an inner ring, wherein the inner ring is fixed on the input shaft sleeve (2), and the rotating planetary carrier (4) is fixed to the outer ring.

5. A three-speed gear mechanism according to claim 1, characterized in that... When both the second sun gear (a2) and the third sun gear (a3) ​​are in a free state, the transmission ratio i1 of the three-speed gear mechanism is 1. When the third sun gear (a3) ​​is locked by the locking mechanism and the second sun gear (a2) is in a free state, the transmission ratio i2 of the three-speed gear mechanism is 1 / (1-Za3×Zb1 / Za1×Zb3), where Za3 is the number of teeth of the third sun gear (a3), Zb1 is the number of teeth of the first planetary gear (b1); Za1 is the number of teeth of the first sun gear (a1), and Zb3 is the number of teeth of the third planetary gear (b3). When the second sun gear (a2) is locked by the locking mechanism and the third sun gear (a3) ​​is in a free state, the transmission ratio i3 of the three-speed gear mechanism is 1 / (1-Za2×Zb1 / Za1×Zb2), where Za2 is the number of teeth of the second sun gear (a2), Zb1 is the number of teeth of the first planetary gear (b1), and Zb2 is the number of teeth of the second planetary gear (b2).

6. A hub motor, characterized in that... It includes the three-speed gear mechanism as described in any one of claims 1-5.

7. The hub motor according to claim 6, characterized in that... It includes a hub housing (12) that is fixed or integrally formed with the output housing, and a mechanism (13), a mechanism planetary reduction mechanism, a mechanism clutch (14), the three-link planetary gear transmission group and the power input mechanism that are sequentially assembled inside the hub housing (12) along the motor shaft (1).

8. The hub motor according to claim 7, characterized in that... The hub housing (12) is fixed by a hub ring (12a) and an end cap (12b). The rotating planetary carrier (4) is fixed to the end cap (12b). The first sun gear (a1) is supported on the motor shaft (1) via a gear bearing (15). The inner circumference of the input bushing (2) is supported on the motor shaft (1) via a bushing bearing (16). The inner side of the end cap (2b) is supported on the periphery of the input bushing (2) via a hub bearing (17).

9. The hub motor according to claim 7, characterized in that... The movement output planetary reduction mechanism includes a fourth sun gear (a4) connected to the movement (13) and several double planetary gears rotatably mounted on the movement output planetary carrier (18). Each double planetary gear includes a fourth planetary gear (b4) and a fifth planetary gear (b5) with progressively increasing outer diameters. The fifth planetary gear (b5) meshes with the fourth sun gear (a4). The movement clutch (14) includes an inner ring fixed to the rotating planetary carrier (4) and an outer ring that meshes with it. The outer ring has a movement output internal gear ring (19) fixed on it, which meshes with the fourth planetary gear (b4).

Images