Hub motor

Abstract

The utility model relates to a hub motor which comprises a middle shaft, a hub assembly, a cover plate assembly, a clutch assembly and a stator and rotor assembly. The hub assembly comprises a box body, an inner gear ring and a hub oil seal. The inner gear ring is fixed in the box body, and a groove hole facilitating clamping and fixing is formed in the box body. The cover plate assembly comprises a cover plate end cover and a cover plate oil seal; a slotted hole convenient for clamping and fixing is formed in the cover plate end cover; the clutch assembly comprises a clutch and a planetary gear; the stator and rotor assembly comprises a stator, a rotor and a sun gear; the planetary gear is connected to the inner gear ring in a meshed mode, and the sun gear is connected with the planetary gear in a meshed mode. The hub motor provided by the utility model can adapt to different clamp tools.

Description

Technical Field

[0001] This application relates to the field of assisted bicycles, and particularly to a hub motor. Background Art

[0002] The European patent EP2921397A1 discloses a hub motor for an electric bicycle, which includes a fixed shaft that can be connected to the frame of the electric bicycle, a hub housing that can rotate relative to the fixed shaft and can be coupled to the wheel structure of the electric bicycle, a motor housed in the hub housing, the motor having an internal stator rigidly connected to the fixed shaft and an external rotor that can rotate relative to the fixed shaft, and a reduction unit.

[0003] Regarding the above related technologies, the inventor believes that during the assembly process of the hub motor, it is necessary to fix and position the hub housing. In the existing design, corresponding tooling needs to be selected according to the shape of the hub housing during the assembly process. Therefore, different assembly tooling is required for hub motors of different specifications and sizes. Utility Model Content

[0004] In order to make the hub motor adaptable to a variety of tooling fixtures during the assembly process, this application provides a hub motor.

[0005] The hub motor provided by this application adopts the following technical solutions:

[0006] A hub motor includes a central shaft, a hub assembly, a cover plate assembly, a clutch assembly, and a stator-rotor assembly; among them

[0007] The hub assembly includes a housing, an internal gear ring, and a hub oil seal; among them, the internal gear ring is fixed inside the housing, the hub oil seal is fixed in the housing, and the housing is provided with slot holes for easy clamping and fixing;

[0008] The cover plate assembly includes a cover plate end cover and a cover plate oil seal; among them, the cover plate oil seal is fixed inside the cover plate end cover, the cover plate end cover and the housing form a closed integral housing, both ends of the central shaft penetrate through the housing and the cover plate end cover respectively, and the cover plate end cover is provided with slot holes for easy clamping and fixing;

[0009] The clutch assembly includes a clutch and a planetary gear; among them, the clutch is fixedly connected to the central shaft, the planetary gear is rotatably connected to the clutch, and the planetary gear is meshed with the internal gear ring;

[0010] The stator-rotor assembly includes a stator, a rotor, and a sun gear; among them, the stator is fixedly connected to the central shaft, the sun gear is fixedly connected to the rotor, and the sun gear is meshed with the planetary gear.

[0011] Optionally, the box body includes a hub end cover and a side plate fixedly connected. The outer edge of the hub end cover has a hub flange. A plurality of hub edge grooves and first flange positioning holes penetrating the hub end cover are formed on the hub flange. The hub edge grooves are arranged rotationally symmetrically about the central axis of the hub end cover.

[0012] Optionally, one end of the side plate away from the hub end cover is provided with a cover plate flange. A plurality of cover plate edge grooves and second flange positioning holes penetrating the cover plate flange are formed on the cover plate flange. The cover plate edge grooves are arranged rotationally symmetrically about the central axis of the hub end cover.

[0013] Optionally, a plurality of hub face grooves equal in number to the hub edge grooves are formed on the outer end face of the hub end cover. A hub strengthening portion is arranged at the connection position between the hub end cover and the side plate, and the hub strengthening portion extends to the hub flange.

[0014] Optionally, a cover plate strengthening portion is arranged on the outer surface of the cover plate end cover. The cover plate strengthening portion forms a groove, and a first cover plate positioning hole is formed in the cover plate strengthening portion.

[0015] Optionally, the cover plate end cover has a central boss, and a plurality of second cover plate positioning holes are formed on the end face of the central boss.

[0016] Optionally, the hub end cover is provided with a cylindrical boss. The central axis is arranged in the cylindrical boss, and a thread is arranged on the outer peripheral surface of the cylindrical boss.

[0017] Optionally, the planetary gear is connected to the clutch through a bearing and a planetary gear shaft, and the planetary gear shaft is fixedly connected to the clutch.

[0018] Optionally, one end of the central axis close to the cover plate end cover is provided with a receiving cavity for receiving a wire harness. The receiving cavity communicates the hub motor with the outside. A key groove for installing a connection key and a snap ring groove for installing a snap ring are formed on the central axis. The snap ring includes an arc portion and end portions. The end portions are arranged at both ends of the arc portion, and a gap is formed between the two end portions. A round hole is formed on the end portion, and the central angle corresponding to the arc portion is greater than 270 degrees.

[0019] Optionally, both ends of the central axis have threaded sections.

[0020] During the assembly process of the in-wheel motor, it is necessary to fix and position the housing and the cover end cap. By setting slots and holes such as the hub edge slot, hub surface slot, cover edge slot, and positioning holes on the housing, the housing can be adapted to different types of jigs and tooling. For example, a three-jaw chuck can be used to fix the housing, or the cooperation between the positioning pin and the hub surface slot can be utilized to achieve rapid pre-positioning. The position of the housing can also be fixed through the cooperation between the positioning pin and the positioning hole. Different from the housing, the cover end cap is more likely to be damaged when being clamped. Therefore, a cover reinforcement part is provided. The groove formed by the cover reinforcement part facilitates the clamping and positioning of the cover end cap. The positioning of the cover end cap can also be achieved through the positioning hole.

[0021] In summary, the present application includes at least one of the following beneficial technical effects:

[0022] By setting slots and holes on the housing and the cover end cap, the housing of the in-wheel motor is convenient for clamping and fixing during the assembly process, and is adapted to different types of tooling jigs. When assembling in-wheel motors of different specifications and sizes, there is no need to replace the tooling jigs;

[0023] Reinforcement parts are added at the weak positions of the housing and the cover end cap, so that the housing of the in-wheel motor will not be deformed or damaged under force during the assembly and clamping process. Description of the Drawings

[0024] Figure 1 is a schematic diagram of the overall structure of an in-wheel motor in an embodiment of the present application.

[0025] Figure 2 is an exploded view of the structure of an in-wheel motor in an embodiment of the present application.

[0026] Figure 3 is a cross-sectional view of the structure of an in-wheel motor in an embodiment of the present application.

[0027] Figure 4 is a schematic diagram of a partial structure of an in-wheel motor in an embodiment of the present application, used to show the structure of the cover assembly.

[0028] Figure 5 is a schematic diagram of an assembly structure of a clutch assembly in an in-wheel motor in an embodiment of the present application.

[0029] Figure 6 is another schematic diagram of an assembly structure of a clutch assembly in an in-wheel motor in an embodiment of the present application.

[0030] Figure 7 is a schematic diagram of the structure of the central shaft of an in-wheel motor in an embodiment of the present application.

[0031] Figure 8 is a cross-sectional view of the structure of the central shaft of an in-wheel motor in an embodiment of the present application.

[0032] Figure 9 This is a schematic structural diagram of a snap ring in a hub motor in an embodiment of the present application.

[0033] Explanation of reference numerals: 100, central shaft; 101, accommodating cavity; 102, keyway; 103, snap ring groove; 110, snap ring; 111, arc portion; 112, end portion; 200, hub assembly; 210, housing; 211, hub end cover; 201, hub edge groove; 202, hub surface groove; 203, cover plate edge groove; 204, first flange positioning hole; 205, second flange positioning hole; 212, side plate; 213, hub strengthening portion; 214, hub flange; 215, cover plate flange; 220, internal gear ring; 230, hub oil seal; 300, cover plate assembly; 310, cover plate end cover; 301, first cover plate positioning hole; 302, second cover plate positioning hole; 311, cover plate strengthening portion; 320, cover plate oil seal; 400, clutch assembly; 410, clutch; 420, planetary gear; 421, bearing; 422, planetary gear shaft; 500, stator-rotor assembly; 510, inner stator; 520, outer rotor; 530, sun gear. Detailed implementation manners

[0034] The following will further elaborate on the present application in conjunction with the attached Figures 1-9 drawings.

[0035] An embodiment of the present application discloses a hub motor. Referring to Figure 1 and Figure 2 , it includes a central shaft 100, a hub assembly 200, a cover plate assembly 300, a clutch assembly 400, and a stator-rotor assembly 500.

[0036] Referring to Figure 2 and Figure 3 , the hub assembly 200 includes a housing 210, an internal gear ring 220, and a hub oil seal 230.

[0037] The housing 210 includes an integrally formed hub end cover 211 and a side plate 212; the hub end cover 211 is generally circular, and the side plate 212 is generally cylindrical, so that the housing 210 forms a hollow cylindrical structure with one end open. The internal gear ring 220 is press-fitted and fixed inside the housing 210, and the outer surface of the internal gear ring 220 is in contact with the inner surface of the side plate 212. One end of the central shaft 100 passes through the center of the hub end cover 211, and the hub oil seal 230 is fixedly installed in the hub end cover 211 to fill the gap between the central shaft 100 and the hub end cover 211.

[0038] The center of the hub end cover 211 has a hollow cylindrical boss, and the outer edge has a hub flange 214. The central shaft 100 is arranged in the cylindrical boss, and the outer surface of the cylindrical boss is provided with threads. The hub flange 214 protrudes from the outer surface of the side plate 212. A plurality of hub edge grooves 201 and a plurality of first flange positioning holes 204 are formed in the hub flange 214, and both the hub edge grooves 201 and the first flange positioning holes 204 penetrate through the hub end cover 211; in this embodiment, six hub edge grooves 201 are provided, and eighteen first flange positioning holes 204 are provided. The plurality of hub edge grooves 201 are arranged in rotational symmetry around the central axis of the hub end cover 211. A plurality of hub surface grooves 202 are formed on the outer end surface of the hub end cover 211; the number and positions of the hub edge grooves 201 and the hub surface grooves 202 correspond to each other. A hub strengthening portion 213 is arranged at the connection position between the hub end cover 211 and the side plate 212. The hub strengthening portion 213 is arranged on the outer surface of the hub end cover 211 and extends to the hub flange 214. The hub surface grooves 202 do not penetrate through the hub end cover 211, and part of the hub surface grooves 202 is located on the hub strengthening portion 213; since the wall thickness is reduced after the hub surface grooves 202 are formed at the connection position between the hub end cover 211 and the side plate 212, the hub strengthening portion 213 is provided for structural reinforcement.

[0039] One end of the side plate 212 away from the hub end cover 211 is provided with an annular cover plate flange 215. A plurality of cover plate edge grooves 203 and second flange positioning holes 205 are formed in the cover plate flange 215, and both the cover plate edge grooves 203 and the second flange positioning holes 205 penetrate through the cover plate flange 215. In this embodiment, six cover plate edge grooves 203 are provided, and eighteen second flange positioning holes 205 are provided. The plurality of cover plate edge grooves 203 are arranged in rotational symmetry around the central axis of the hub end cover 211.

[0040] During the assembly process of the in-wheel motor, it is necessary to grip or fix the housing 210; for example, during the assembly of the hub assembly 200, it is necessary to press-fit the internal gear ring 220 into the housing 210, and the housing 210 needs to be fixed during the press-fitting process. By providing the hub edge grooves 201, the hub surface grooves 202, the cover plate edge grooves 203 and the positioning holes, the housing 210 can be adapted to different types of jigs and toolings. For example, a three-jaw chuck can be used to fix the housing 210, and the three jaws of the chuck are respectively clamped in the hub edge grooves 201, and the hub surface grooves 202 can be quickly pre-positioned through cooperation with a positioning pin. The position of the housing 210 can also be fixed through the cooperation of the positioning pin and the positioning hole. In other assembly steps of the in-wheel motor, the housing 210 can also be gripped or fixed by similar methods using the slots on the housing 210, which will not be elaborated one by one here.

[0041] Refer to Figure 2 and Figure 4, the cover plate assembly 300 includes a cover plate end cap 310 and a cover plate oil seal 320. The cover plate end cap 310 is generally circular and is press-fitted and fixed at the opening position of the box body 210. The cover plate end cap 310 and the box body 210 cooperate to form an internally enclosed hub motor housing. One end of the central shaft 100 passes through the central boss of the cover plate end cap 310, and the cover plate oil seal 320 is fixedly installed in the cover plate end cap 310 to fill the gap between the central shaft 100 and the cover plate end cap 310.

[0042] A cover plate strengthening portion 311 is provided on the outer surface of the cover plate end cap 310. The cover plate strengthening portion 311 includes two parallel reinforcing ribs, and the reinforcing ribs extend to protrude beyond the outer edge of the cover plate end cap 310. A first cover plate positioning hole 301 is provided at the position where the cover plate strengthening portion 311 protrudes beyond the cover plate end cap 310. A plurality of second cover plate positioning holes 302 are provided on the end face of the central boss of the cover plate end cap 310.

[0043] During the assembly process of the hub motor, it is necessary to grip or fix the cover plate end cap 310. Different from the box body 210, the cover plate end cap 310 is more likely to be damaged when being clamped, so the cover plate strengthening portion 311 is provided. The groove formed between the two reinforcing ribs in the cover plate strengthening portion 311 facilitates the clamping and positioning of the cover plate end cap 310. The positioning of the cover plate end cap 310 can also be achieved through the positioning holes.

[0044] Refer to Figure 2 and Figure 3 , the clutch assembly 400 includes a clutch 410 and three planetary gears 420. The clutch 410 is key-connected to the central shaft 100. The three planetary gears 420 are rotationally symmetrically arranged around the center of the clutch 410. The planetary gears 420 are meshed and connected to the internal gear ring 220. The planetary gears 420 are connected to the clutch 410 through bearings 421 and planetary gear shafts 422. The planetary gear shafts 422 are fixedly connected to the clutch 410. The inner ring of the bearing 421 is in interference fit with the planetary gear shaft 422, and the outer ring of the bearing 421 is in interference fit with the planetary gear 420.

[0045] Refer to Figure 5 and Figure 6 , the fixed connection between the clutch 410 and the planetary gear shaft 422 can be achieved in various ways. For example, the planetary gear shaft 422 is formed on the end face shell of the clutch 410 by an integral molding method. In addition, the fixed connection between the two can also be achieved by press-fitting one end of the planetary gear shaft 422 through the clutch 410.

[0046] Refer to Figure 3, the stator-rotor assembly 500 includes an inner stator 510, an outer rotor 520, and a sun gear 530. The inner stator 510 is key-connected to the central shaft 100. The outer rotor 520 is rotatably sleeved on the central shaft 100. The sun gear 530 is press-fitted and coaxially fixed to the outer rotor 520. The sun gear 530 is meshed and connected with the planetary gear 420. The structures of the inner stator 510 and the outer rotor 520 can adopt the motor stator-rotor structures in the conventional technologies, which will not be elaborated here.

[0047] Referring to Figure 7 and Figure 8 , optionally, both ends of the central shaft 100 are provided with threaded segments. One end of the central shaft 100 close to the cover end cap 310 is provided with a receiving cavity 101 for receiving a wire harness. The receiving cavity 101 communicates the hub motor with the outside. One opening end of the receiving cavity 101 corresponds to the position of the inner stator 510, and the other opening end can be provided on the circumferential side of the central shaft 100 close to the end, or can be provided on the end face of the central shaft 100. A keyway 102 for installing a connection key and a snap ring groove 103 for installing a snap ring 110 are formed on the central shaft 100. The snap ring groove 103 is an annular through groove, and a plurality of snap ring grooves 103 are arranged along the axial direction of the central shaft 100.

[0048] Referring to Figure 9 , the snap ring 110 includes an arc portion 111 and end portions 112. The end portions 112 are arranged at both ends of the arc portion 111 and protrude from the outer periphery of the arc portion 111. The snap ring 110 is made of an elastic material, and round holes are formed on the end portions 112. The central angle corresponding to the arc portion 111 is greater than 270 degrees, and a gap is formed between the two end portions 112.

[0049] The central shaft 100 is fixedly connected to the bicycle frame, and the box body 210 is fixedly connected to the bicycle hub. The external power supply can supply power to the inner stator 510 through the wire harness. The inner stator 510 drives the outer rotor 520 and the sun gear 530 to rotate based on the principle of electromagnetic induction. Since the sun gear 530, the three planetary gears 420, and the internal gear ring 220 form a planetary gear train, the box body 210, the internal gear ring 220, and the cover end cap 310 are driven to rotate, thereby realizing driving the bicycle hub to rotate.

[0050] In the embodiments of the present application, two components with a relative rotation tendency can be connected through bearings. For example, a bearing is provided between the central shaft 100 and the box body 210, and a bearing is also provided between the central shaft 100 and the cover end cap 310. Each component with a rotational relationship will not be listed one by one here.

[0051] The above are all the preferred embodiments of the present application. The protection scope of the present application is not limited accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A wheel hub motor, characterized in that: It includes a central shaft, a hub assembly, a cover plate assembly, a clutch assembly and a stator-rotor assembly; among them The hub assembly includes a housing, an internal gear ring and a hub oil seal; wherein, the internal gear ring is fixed inside the housing, the hub oil seal is fixed in the housing, and the housing is provided with slot holes for convenient clamping and fixing; The cover plate assembly includes a cover plate end cover and a cover plate oil seal; wherein, the cover plate oil seal is fixed inside the cover plate end cover, the cover plate end cover and the housing form a closed integral housing, both ends of the central shaft pass through the housing and the cover plate end cover respectively, and the cover plate end cover is provided with slot holes for convenient clamping and fixing; The clutch assembly includes a clutch and a planetary gear; wherein, the clutch is fixedly connected to the central shaft, the planetary gear is rotatably connected to the clutch, and the planetary gear is meshed with the internal gear ring; The stator-rotor assembly includes a stator, a rotor and a sun gear; wherein, the stator is fixedly connected to the central shaft, the sun gear is fixedly connected to the rotor, and the sun gear is meshed with the planetary gear.

2. The hub motor according to claim 1, wherein: The housing includes a hub end cover and a side plate which are fixedly connected. The outer edge of the hub end cover has a hub flange. The hub flange is provided with a plurality of hub side grooves and first flange positioning holes penetrating through the hub end cover. The hub side grooves are symmetrically arranged about the central axis of the hub end cover.

3. A hub motor according to claim 2, characterized in that: One end of the side plate away from the hub end cover is provided with a cover plate flange. The cover plate flange is provided with a plurality of cover plate side grooves and second flange positioning holes penetrating through the cover plate flange. The cover plate side grooves are symmetrically arranged about the central axis of the hub end cover.

4. A hub motor according to claim 2, wherein: The outer end surface of the hub end cover is provided with hub surface grooves having the same number as the hub side grooves. A hub strengthening part is arranged at the connection position between the hub end cover and the side plate, and the hub strengthening part extends to the hub flange.

5. A hub motor according to claim 1, characterized in that: A cover plate strengthening part is arranged on the outer surface of the cover plate end cover. The cover plate strengthening part forms a groove, and the cover plate strengthening part is provided with a first cover plate positioning hole.

6. The hub motor according to claim 5, characterized in that: The cover plate end cover has a central boss, and a plurality of second cover plate positioning holes are arranged on the end surface of the central boss.

7. The hub motor according to claim 2, wherein: The hub end cover is provided with a cylindrical boss. The central shaft is arranged in the cylindrical boss, and the outer peripheral surface of the cylindrical boss is provided with threads.

8. The hub motor according to claim 1, wherein: The planetary gear is connected to the clutch through a bearing and a planetary gear shaft, and the planetary gear shaft is fixedly connected to the clutch.

9. The hub motor according to claim 1, characterized in that: One end of the central shaft close to the cover plate end cover is provided with a receiving cavity for accommodating a wire harness. The receiving cavity communicates the hub motor with the outside. The central shaft is provided with a key groove for installing a connection key and a snap ring groove for installing a snap ring. The snap ring includes an arc part and end parts. The end parts are convex out of the outer periphery of the arc part at both ends of the arc part. A gap is formed between the two end parts. The end parts are provided with round holes, and the central angle corresponding to the arc part is greater than 270 degrees.

10. A hub motor according to claim 9, wherein: Both ends of the central shaft have threaded sections.

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