Power transmission mechanism and hub motor applying same

Abstract

The invention discloses a power transmission mechanism and a hub motor applying the same, belongs to the technical field of bicycles, and solves the problems that an existing transmission mechanism is large in size, not light enough and low in reduction ratio. A power transmission mechanism is applied to a hub motor and comprises a motor assembly and a planetary reducer connected with the motor assembly, the motor assembly comprises a shell body, a stator unit and a rotor unit, the stator unit and the rotor unit are arranged in the shell body, and the shell body is connected with the planetary reducer. The planetary reducer is provided with an input end and an output end, the input end is connected with the rotor unit, and the output end is connected with a clutch in the hub motor. The rotor unit transmits the power to the input end, the output end transmits the power to the clutch in the hub motor at a variable speed, and the planetary reducer improves the reduction ratio through two-stage speed reduction, so that the adaptability of the planetary reducer is improved when the planetary reducer is applied to the hub motor.

Description

Technical Field

[0001] This invention belongs to the field of bicycle technology, specifically relating to a power transmission mechanism and a hub motor using the same. Background Technology

[0002] Bicycles are currently very popular, used for long-distance riding such as touring, commuting, and racing. Shifting gears is often necessary during riding. Essential components of a multi-speed bicycle are the motor and gearbox. Traditional motors are relatively large, connecting to the reducer in the hub motor via an input shaft, which takes up considerable space and makes the bicycle heavy and not lightweight. Furthermore, current reducers suffer from low reduction ratios and limited practicality. Summary of the Invention

[0003] The purpose of this invention is to provide a power transmission mechanism and a hub motor using the same, which solves the problems of existing transmission mechanisms being large in size, not lightweight enough, and having a low reduction ratio.

[0004] To achieve the above objectives, the technical solution of the present invention is implemented as follows: A power transmission mechanism for a hub motor includes a motor assembly and a planetary reducer connected to the motor assembly. The motor assembly includes a housing, a stator unit, and a rotor unit. The stator unit and the rotor unit are disposed inside the housing. The housing is connected to the planetary reducer, which has an input end and an output end. The input end is connected to the rotor unit, and the output end is connected to a clutch in the hub motor. In use, the stator unit drives the rotor unit to rotate, the rotor unit transmits power to the input end, and the output end transmits power at a variable speed to the clutch in the hub motor.

[0005] In some embodiments, the planetary reducer includes a first planetary gear train, a second planetary gear train, and a frame. One end of the first planetary gear train is connected to the motor assembly, the other end of the first planetary gear train is connected to one side of the frame, the other side of the frame is connected to the second planetary gear train, and the first planetary gear train is connected to the housing body.

[0006] In some embodiments, the frame includes a planetary carrier and a second sun gear disposed in the middle of one side of the planetary carrier, the first planetary gear train is movably connected to the other side of the planetary carrier, and the second sun gear is movably connected to the second planetary gear train.

[0007] In some embodiments, the first planetary gear train includes a first sun gear, a first planet gear, and a first ring gear. The first sun gear is connected to the rotor unit, the first sun gear meshes with the first planet gear, the first planet gear is located on the other side of the planet carrier, the first planet gear meshes with the first ring gear, and the first ring gear is fixedly connected to the motor assembly.

[0008] In some embodiments, a central shaft is provided on the side of the first sun gear near the planet carrier, and the central shaft rotatably passes through the planet carrier and the second sun gear.

[0009] In some embodiments, the second planetary gear train includes a second planetary gear and a second ring gear. The second planetary gear is disposed on one side of the planetary carrier. The second sun gear meshes with the second planetary gear. The second planetary gear meshes with the second ring gear. The second ring gear is connected to a clutch in the hub motor.

[0010] In some embodiments, the planet carrier has several fixed shafts on both sides, the first planet gear and the second planet gear are respectively disposed on the fixed shafts, and the fixed shafts are also provided with axial positioning structures that contact the first planet gear and the second planet gear.

[0011] In some embodiments, the motor assembly further includes an output shaft, through which the rotor unit is connected to one end of the first planetary gear train.

[0012] In some embodiments, the housing body is cantilevered to the planetary gear reducer.

[0013] In some embodiments, the housing body is provided with a stop, and the planetary reducer is provided with a first protrusion adapted to the stop.

[0014] In some embodiments, the end faces of the housing body and the planetary reducer that fit together are also connected by welding, gluing or bolting.

[0015] Another technical solution of the present invention is implemented as follows: A hub motor includes the aforementioned power transmission mechanism, clutch, and hub housing. The power transmission mechanism is connected to the clutch, and both the power transmission mechanism and the clutch are located within the hub housing.

[0016] Compared with the prior art, in this invention, the motor assembly is applied to a hub motor. The housing body is connected to the planetary reducer. The stator unit drives the rotor unit to rotate. The rotor unit transmits power to the input end. The output end transmits power to the clutch in the hub motor through speed change. The planetary reducer improves the reduction ratio through two-stage reduction, which increases its adaptability when applied to the hub motor. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the power transmission mechanism provided in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the planetary reducer in the power transmission mechanism provided in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the frame structure in the planetary reducer provided in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the structure of the second planetary gear train in the planetary reducer provided in Embodiment 1 of the present invention; Figure 5 This is a cross-sectional view of the planetary reducer provided in Embodiment 1 of the present invention; Figure 6 This is a schematic diagram of the structure of the motor assembly provided in Embodiment 1 of the present invention; Figure 7 This is a cross-sectional view of the motor assembly provided in Embodiment 1 of the present invention; Figure 8 This is a schematic diagram of the hub motor provided in Embodiment 2 of the present invention; Figure 9 This is a schematic diagram of the hub motor provided in Embodiment 2 of the present invention with the hub housing removed.

[0018] In the diagram, 1. Motor assembly, 11. Housing body, 111. Stop, 12. Stator unit, 13. Rotor unit, 14. Output shaft, 2. Planetary reducer, 21. First planetary gear train, 211. First sun gear, 2111-Central shaft, 212. First planetary gear, 213. First gear ring, 2131. First protrusion, 22. Second planetary gear train, 221. Second planetary gear, 222. Second gear ring, 23. Frame, 231. Planet carrier, 232. Second sun gear, 233. Fixed shaft. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0020] In the description of this invention, it should be clarified that the terms "vertical," "lateral," "longitudinal," "front," "rear," "left," "right," "up," "down," and "horizontal," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are merely for the convenience of describing this invention. They do not imply that the device or element referred to must have a specific orientation or position, and therefore should not be construed as a limitation of this invention. In the description of this invention, it should be noted that unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Example 1

[0021] The power transmission mechanism provided in Embodiment 1 of the present invention, such as Figure 1 As shown, an application in a hub motor includes a motor assembly 1 and a planetary reducer 2 connected to the motor assembly 1. The motor assembly 1 includes a housing body 11, a stator unit 12, and a rotor unit 13. The stator unit 12 and the rotor unit 13 are located inside the housing body 11. The housing body 11 is connected to the planetary reducer 2, which has an input end and an output end. The input end is connected to the rotor unit 13, and the output end is connected to the clutch in the hub motor. In use, the stator unit 12 drives the rotor unit 13 to rotate, the rotor unit 13 transmits power to the input end, and the output end transmits power at a variable speed to the clutch in the hub motor.

[0022] After adopting the above solution, the motor assembly 1 is applied to the hub motor. The outer shell 11 is connected to the planetary reducer 2. The stator unit 12 drives the rotor unit 13 to rotate. The rotor unit 13 transmits power to the input end. The output end transmits power to the clutch in the hub motor through speed change. The planetary reducer 2 improves the reduction ratio through two-stage reduction, which increases its adaptability when applied to the hub motor.

[0023] In the specific implementation process of this embodiment 1, such as Figure 2 As shown, the planetary reducer 2 includes a first planetary gear train 21, a second planetary gear train 22, and a frame 23. One end of the first planetary gear train 21 is connected to the motor assembly 1, and the other end of the first planetary gear train 21 is connected to one side of the frame 23. The other side of the frame 23 is connected to the second planetary gear train 22, and the first planetary gear train 21 is connected to the outer shell 11.

[0024] More specifically, the rotor unit 13 in the motor assembly 1 transmits power to the first planetary gear train 21 for primary reduction, and the frame 23 transmits the power after primary reduction to the second planetary gear train 22 for secondary reduction. This planetary reducer 2 increases the reduction ratio through two-stage reduction, thus enhancing its adaptability when applied to hub motors. Traditional multi-stage transmission reduction often uses multiple planetary carriers, while the planetary reducer 2 achieves two-stage reduction by setting a single frame 23 and placing the first planetary gear train 21 and the second planetary gear train 22 on opposite sides of the frame 23. This simplifies the mechanism, resulting in a smaller reducer and a more compact transmission structure.

[0025] In the specific implementation process of this embodiment 1, such as Figure 2 , Figure 3 As shown, the frame 23 includes a planetary carrier 231 and a second sun gear 232 disposed in the middle of one side of the planetary carrier 231. The first planetary gear train 21 is movably connected to the other side of the planetary carrier 231, and the second sun gear 232 is movably connected to the second planetary gear train 22.

[0026] More specifically, when the motor assembly 1 transmits power to the first planetary gear train 21, the first planetary gear train 21 is movably connected to the planet carrier 231, thereby transmitting power to the planet carrier 231. The planet carrier 231 rotates accordingly, thereby driving the second sun gear 232 to rotate. The second sun gear 232 transmits power to the second planetary gear train 22, thereby completing the deceleration.

[0027] In the specific implementation process of this embodiment 1, such as Figure 2 As shown, the first planetary gear train 21 includes a first sun gear 211, a first planet gear 212, and a first ring gear 213. The first sun gear 211 is connected to the rotor unit 13, and the first sun gear 211 meshes with the first planet gear 212. The first planet gear 212 is located on the other side of the planet carrier 231, and the first planet gear 212 meshes with the first ring gear 213. The first ring gear 213 is fixedly connected to the motor assembly 1.

[0028] More specifically, the rotor unit 13 in the motor assembly 1 is fixedly connected to the center of the first sun gear 211 to transmit power to the first sun gear 211. When the first sun gear 211 rotates, since the first gear ring 213 is fixedly connected to the motor assembly 1, the first gear ring 213 is in a locked state. Therefore, the first sun gear 211 meshes with the first planet gear 212 to drive the first planet gear 212 to perform circumferential motion, and the first planet gear 212 drives the planet carrier 231 to rotate.

[0029] In the specific implementation of this embodiment 1, a central shaft 2111 is provided on the side of the first sun gear 211 near the planet carrier 231, and the central shaft 2111 is rotatably inserted through the planet carrier 231 and the second sun gear 232.

[0030] If the central shaft 2111 is not provided, the first sun gear 211 is only connected to the first planet gear 212 and the planet carrier 231 through external meshing, resulting in poor stability during use. This embodiment improves the coaxiality of the first sun gear 211 with the planet carrier 231 and the second sun gear 232 by providing the central shaft 2111, thus ensuring stability during long-term use.

[0031] In the specific implementation process of this embodiment 1, such as Figure 4 As shown, the second planetary gear train 22 includes a second planetary gear 221 and a second ring gear 222. The second planetary gear 221 is disposed on one side of the planetary carrier 231. The second sun gear 232 meshes with the second planetary gear 221. The second planetary gear 221 meshes with the second ring gear 222. The second ring gear 222 is connected to the clutch in the hub motor.

[0032] More specifically, the first planetary gear 212 drives the planet carrier 231 to rotate, and the second sun gear 232 on the planet carrier 231 rotates accordingly, which in turn drives the second planetary gear 221 meshing with the second sun gear 232 to rotate, and then the second ring gear 222 rotates. The second ring gear 222 is connected to the clutch, and the second ring gear 222 transmits power to the clutch.

[0033] Furthermore, such as Figure 2 As shown, the first gear ring 213 has a first protrusion 2131 on the end face facing the motor assembly 1. The first gear ring 213 is fixedly connected to the motor assembly 1 through the first protrusion 2131, so that the first gear ring 213 is fixed and locked.

[0034] Furthermore, the first protrusion 2131 is evenly distributed on the first gear ring 213. When the first gear ring 213 is connected to the motor assembly 1 through the first protrusion 2131, it can serve the purpose of stopping and centering.

[0035] Furthermore, such as Figure 5 As shown, the planetary carrier 231 has several fixed shafts 233 on both sides. The first planetary gear 212 and the second planetary gear 221 are respectively mounted on the fixed shafts 233. The fixed shafts 233 are also provided with axial positioning structures that contact the first planetary gear 212 and the second planetary gear 221.

[0036] The planetary carrier 231 has several holes, and the fixed shaft 233 is mounted on the planetary carrier 231 through the holes. The fixed shaft 233 can also be mounted on the planetary carrier 231 by bolts, screws or other means.

[0037] The axial positioning structure consists of two shims mounted on the fixed shaft 233, which abut against the sides of the first planetary gear 212 or the second planetary gear 221, respectively. By providing this axial positioning structure, dry friction between the first planetary gear 212, the second planetary gear 221 and the fixed shaft 233 can be avoided, reducing wear and noise on the first planetary gear 212 and the second planetary gear 221, and extending their service life.

[0038] Furthermore, both the first planetary gear 212 and the second planetary gear 221 are connected to the fixed shaft 233 via bearings. A radial bearing is provided between the first planetary gear 212 and the second planetary gear 221, and thrust bearings are provided on the opposite end faces of the first planetary gear 212 and the second planetary gear 221. During the relative movement of the first planetary gear 212 and the second planetary gear 221, the friction between the end faces is reduced, noise is reduced, and service life is increased. The radial bearing is located in the middle of the two thrust bearings, so that the planetary carrier 231 maintains a stable relative movement with the first planetary gear 212 and the second planetary gear 221, thereby improving the stability and safety of the reducer.

[0039] In the specific implementation process of this embodiment 1, such as Figure 6 and Figure 7 As shown, the motor assembly 1 also includes an output shaft 14, and the rotor unit 13 is connected to one end of the first planetary gear train 21 through the output shaft 14.

[0040] More specifically, the output shaft 14 is connected to the rotor unit 13, and transmits the power of the rotor unit 13 to the first sun gear 211 in the first planetary gear train 21 through the output shaft 14.

[0041] In the specific implementation process of this embodiment 1, the outer shell 11 is cantileveredly connected to the planetary reducer 2.

[0042] More specifically, in use, the outer casing 11 is cantilevered to the reducer in the hub motor, which is convenient to assemble and has a small size. The stator unit 12 drives the rotor unit 13 to rotate, and the rotor unit 13 drives the reducer of the hub motor to rotate, thereby driving the hub motor to rotate. The hub motor transmits power to the wheel.

[0043] In the specific implementation process of this embodiment 1, such as Figure 6As shown, the outer shell body 11 is provided with a stop 111, and the planetary reducer 2 is provided with a first protrusion 2131 that matches the stop 111.

[0044] More specifically, during use, the outer shell 11 is connected to the planetary reducer 2 through the cooperation of the stop 111 and the first protrusion 2131, so that the first gear ring 213 is fixed and locked. This cooperation method not only makes the structure more compact, but also serves the purpose of stopping and centering during assembly.

[0045] Furthermore, the mating ends of the housing 11 and the planetary reducer 2 are connected by welding, gluing, or bolting, further increasing the connection strength and service life of both. Figure 6 As shown, in some embodiments, threaded holes with matching positions are provided on the end faces of the housing body 11 and the planetary reducer 2 that are in contact with each other. After the stop 111 is connected with the first protrusion 2131, the bolt is passed through the threaded hole to achieve secondary reinforcement of the housing body 11 and the planetary reducer 2, thereby improving the reliability of the connection between the two.

[0046] The workflow provided in Embodiment 1 of the present invention is as follows: The stator unit 12 drives the rotor unit 13 to rotate. The rotor unit 13 transmits the force of the rotor unit 13 rotation to the output shaft 14, and then the output shaft 14 transmits the force to the first sun gear 211. The first sun gear 211 rotates. Since the first ring gear 213 is fixedly connected to the motor assembly 1, the first ring gear 213 is in a locked state. Therefore, the first sun gear 211 meshes with the first planet gear 212, driving the first planet gear 212 to perform circumferential motion, completing the first stage of deceleration. The first planet gear 212 drives the planet carrier 231 to rotate. The second sun gear 232 on the planet carrier 231 rotates, driving the second planet gear 221 to rotate, and then the second ring gear 222 rotates. The second ring gear 222 connects to the clutch, thus completing the second stage of deceleration. The second ring gear 222 transmits power to the clutch, completing the power transmission. Example 2

[0047] Embodiment 2 of the present invention provides a hub motor, such as Figure 8 and Figure 9 As shown, the device includes the power transmission mechanism, clutch, and wheel hub housing described in Embodiment 1. The power transmission mechanism is connected to the clutch, and both the power transmission mechanism and the clutch are located inside the wheel hub housing.

[0048] More specifically, the motor assembly 1 in the hub motor transmits force to the reducer for deceleration, and the reducer transmits torque to the clutch. The hub motor using this reducer has the characteristics of simple structure and light weight.

[0049] In summary, the motor assembly 1 of the present invention is applied to a hub motor. The housing body 11 is connected to the planetary reducer 2. The stator unit 12 drives the rotor unit 13 to rotate. The rotor unit 13 transmits power to the input end. The output end transmits power to the clutch in the hub motor through speed change. The planetary reducer 2 improves the reduction ratio through two-stage reduction, thereby increasing its adaptability when applied to the hub motor.

[0050] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A power transmission mechanism applied to an in-wheel motor, characterized by, The application relates to a motor assembly (1) and a planetary reducer (2) connected with the motor assembly (1), wherein the motor assembly (1) comprises a shell body (11), a stator unit (12) and a rotor unit (13), the stator unit (12) and the rotor unit (13) are arranged inside the shell body (11), the shell body (11) is connected with the planetary reducer (2), the planetary reducer (2) has an input end and an output end, the input end is connected with the rotor unit (13), and the output end is connected with a clutch in a hub motor; in use, the stator unit (12) drives the rotor unit (13) to rotate, the rotor unit (13) transmits power to the input end, and the output end transmits power to the clutch in the hub motor.

2. The power transmission mechanism of claim 1, wherein The planetary reducer (2) comprises a first planetary gear train (21), a second planetary gear train (22) and a frame body (23), one end of the first planetary gear train (21) is connected with the motor assembly (1), the other end of the first planetary gear train (21) is connected with one side of the frame body (23), the other side of the frame body (23) is connected with the second planetary gear train (22), and the first planetary gear train (21) is connected with the shell body (11).

3. The power transmission mechanism of claim 2, wherein, The frame body (23) comprises a planet carrier (231) and a second sun gear (232) arranged at the middle of one side of the planet carrier (231), the first planetary gear train (21) is movably connected with the other side of the planet carrier (231), and the second sun gear (232) is movably connected with the second planetary gear train (22).

4. The power transmission mechanism of claim 3, wherein The first planetary gear train (21) comprises a first sun gear (211), a first planetary gear (212) and a first ring gear (213), the first sun gear (211) is connected with the rotor unit (13), the first sun gear (211) is engaged with the first planetary gear (212), the first planetary gear (212) is arranged at the other side of the planet carrier (231), the first planetary gear (212) is engaged with the first ring gear (213), and the first ring gear (213) is fixedly connected with the motor assembly (1).

5. The power transmission mechanism of claim 4, wherein, The first sun gear (211) is provided with a central shaft (2111) close to one side of the planet carrier (231), and the central shaft (2111) rotates and is arranged in the planet carrier (231) and the second sun gear (232).

6. The power transmission mechanism of claim 5, wherein, The second planetary gear train (22) comprises a second planetary gear (221) and a second ring gear (222), the second planetary gear (221) is arranged at one side of the planet carrier (231), the second sun gear (232) is engaged with the second planetary gear (221), the second planetary gear (221) is engaged with the second ring gear (222), and the second ring gear (222) is connected with the clutch in the hub motor.

7. A power transmission mechanism according to any one of claims 3 to 6, wherein The planet carrier (231) is respectively provided with a plurality of fixed shafts (233) on both sides, the first planetary gear (212) and the second planetary gear (221) are respectively arranged on the fixed shafts (233), and the fixed shafts (233) are further provided with axial positioning structures in contact with the first planetary gear (212) and the second planetary gear (221).

8. The power transmission mechanism according to any one of claims 1 to 6, characterized in that, The shell body (11) is provided with a stop opening (111), and the planetary reducer (2) is provided with a first protrusion (2131) matched with the stop opening (111).

9. The power transmission mechanism of claim 8, wherein, The end faces of the shell body (11) and the planetary reducer (2) that are mutually attached are further connected through welding, gluing or bolt connection.

10. A wheel hub motor, characterized by The power transmission mechanism, the clutch and the hub shell are connected, and the power transmission mechanism and the clutch are arranged in the hub shell.

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