A hub motor for a cycling device

Abstract

The application discloses a kind of hub motor for riding equipment, a kind of hub motor for riding equipment, including middle shaft, motor body, speed reducer, hub ring and tooth disc, motor body, speed reducer are housed in the cavity of hub ring, and are respectively set on middle shaft, middle shaft is arranged in hub ring, and its one end on the outside of hub ring is set with tooth disc;Motor body includes rotor piece, stator piece and stator support, rotor piece is coaxially set on middle shaft, stator piece is set on rotor piece, stator support is wrapped in stator piece, and stator support is integrally formed by injection molding;Speed reducer includes planet carrier and gear ring, gear ring is integrally formed by injection molding with stator support, both ends of planet carrier are provided with support bearing, wherein, the outer wall of the output shaft of rotor piece and planet carrier form bearing chamber for installing support bearing between.The application realizes the requirements of small size, light weight.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a hub motor for cycling equipment. Background Technology

[0002] Given the diverse operating environments of electric bicycles powered by new energy sources, customers have a pressing need for high-speed hub motors, taking hub motors as an example. Due to the installation requirements of hub motors, achieving a high reduction ratio within a compact size has always been a technical challenge.

[0003] In existing technologies, stator housings are generally made of metal to facilitate heat dissipation. The stator housing not only needs to form a stator support to cooperate with the rotor in supporting the bearings shown in the diagram, fulfilling the first fitting requirement, but it also needs to be fixed to the planetary gear ring to ensure the rotation of the planetary gears, fulfilling the second fitting requirement. Because the space inside the hub is limited, and the fitting and fixing require additional locking parts, this undoubtedly increases the size and weight of the motor. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a hub motor for cycling equipment that achieves miniaturization and lightweight design.

[0005] This invention is achieved through the following technical solution:

[0006] A hub motor for cycling equipment includes a bottom bracket, a motor body, a reducer, a hub ring, and a chainring. The motor body and the reducer are housed in the cavity of the hub ring and respectively fitted onto the bottom bracket. The bottom bracket passes through the hub ring, and the chainring is fitted onto one end of the bottom bracket located outside the hub ring.

[0007] The motor body drives the reducer to rotate the hub, or the crankshaft drives the hub to rotate;

[0008] The motor body includes a rotor component, a stator component, and a stator support. The rotor component is coaxially sleeved on the central shaft, the stator component is sleeved on the rotor component, and the stator support is wrapped around the stator component. The stator support is integrally formed by injection molding.

[0009] The reducer includes a planetary carrier and a gear ring. The gear ring and the stator support are integrally formed by injection molding. Support bearings are provided at both ends of the planetary carrier. A bearing chamber for installing the support bearings is formed between the outer wall of the output shaft of the rotor and the planetary carrier.

[0010] Furthermore, the planetary carrier has multiple protrusions on the side facing the rotor, and the protrusions and the rotor together form the corresponding bearing chamber.

[0011] Furthermore, the protrusion is located between two adjacent planetary gears of the reducer.

[0012] Furthermore, the end face of the stator bracket facing the reducer is the first end face, and a tooth groove is formed on the inner sidewall of the gear ring, with one end of the tooth groove extending axially to the first end face.

[0013] Furthermore, the end face of the support bearing facing the motor body extends axially past the first end face into the cavity of the motor body.

[0014] Furthermore, the stator component includes a stator core, and the stator bracket is partially or completely hollowed out corresponding to the position of the stator core.

[0015] Furthermore, the end face of the stator bracket facing away from the reducer is a second end face, which is injection molded in a covering shape.

[0016] Furthermore, the reducer also includes a primary sun gear, which is integrated into the output section of the rotor component.

[0017] Furthermore, the rotor component includes a rotor support, a rotor body that mates with the outer peripheral surface of the rotor support, the first-stage sun gear integrated on the rotor support, and the bearing housing formed between the rotor support and the planetary carrier.

[0018] Furthermore, the planetary carrier of the reducer includes a primary planetary carrier and a secondary planetary carrier. The reducer also includes a primary planetary gear, which is rotatably mounted on the primary planetary carrier and simultaneously meshes with the primary sun gear and the ring gear.

[0019] Furthermore, the reducer also includes a secondary sun gear and a secondary planetary gear. The secondary sun gear is integrally formed on the side of the primary planetary carrier opposite to the primary planetary gear. The secondary planetary gear is rotatably mounted on the secondary planetary carrier and meshes with both the secondary sun gear and the ring gear.

[0020] Furthermore, the motor body and the reducer are axially connected by a central shaft, at least one first bearing is provided between the rotor support and the central shaft, the support bearing is provided between the rotor support and the first-stage planetary carrier, and the support bearing is also provided between the second-stage planetary carrier and the central shaft, so as to rotatably connect the rotor and the reducer to the central shaft.

[0021] Furthermore, a first one-way valve is provided between the output end of the secondary planetary carrier and the hub ring. The motor body can drive the reducer to rotate and then drive the hub ring to rotate through the first one-way valve. At this time, the first one-way valve is in a locked state.

[0022] Furthermore, the hub motor also includes a freehub base, which is connected to the bottom bracket via at least one second bearing. The chainring is fitted onto the outer circumferential surface of the freehub base, and a second one-way valve is provided between the freehub base and the hub. The user can drive the chainring to rotate by stepping on the pedal, and the chainring drives the freehub base to rotate synchronously. The freehub base drives the hub to rotate via the second one-way valve. At this time, the second one-way valve is in a locked state, and the first one-way valve is in an unlocked state.

[0023] Furthermore, the hub motor also includes a control unit, which includes a PCB circuit board and lead-out terminals, and the PCB circuit board is disposed inside the hub ring.

[0024] Furthermore, the lead-out terminal includes multiple pins, the input end of which is connected to the PCB circuit board, and the output end of which is exposed outside the hub ring for connecting to external terminals.

[0025] Furthermore, the lead-out terminal includes multiple sockets, the input end of which is connected to the PCB circuit board, and the output end of which is used to connect to external terminals.

[0026] Compared with the prior art, the advantages of this invention are:

[0027] 1. By forming multiple heat dissipation blades on the inner wall of the hub ring, these blades create a closed-loop airflow circuit within the sealed cavity of the hub motor as the hub ring rotates. At least a portion of this closed-loop airflow circuit is formed on the inner wall of the hub ring. As the hub rotates, the heat dissipation blades direct the concentrated airflow from the stator and rotor to other areas, allowing the hot airflow to act on various parts of the inner wall of the hub ring, thereby increasing the heat dissipation area and efficiency. Compared to existing technologies that rely on air inlets and outlets for air exchange, this application effectively solves the waterproofing problem.

[0028] 2. A clearance space is formed by the stator bracket corresponding to the position of the heat dissipation fins. The heat dissipation fins are at least partially housed in the clearance space. The clearance space is formed by completely or partially omitting the side wall of the stator bracket. This not only reduces the weight of the hub motor but also reduces the radial dimension of the hub motor, thereby achieving miniaturization and weight reduction of the hub motor.

[0029] 3. By setting the splice of adjacent stator cores at the yoke of a single-tooth core, and combining the injection molding process to wrap the shell on the stator component, the strength of the spliced ​​stator component can be guaranteed, and the length of the stator core teeth will not be increased, thus satisfying the characteristics of compact structure and small size.

[0030] 4. The end face of the housing facing the reducer is completely hollowed out, reducing the axial dimension of the hub motor.

[0031] 5. By eliminating the end face of the housing facing the reducer, on the one hand, the first-stage planetary carrier of the reducer can extend into the gap between the rotor and stator components, eliminating the need for stator support and thus reducing the axial dimension of the hub motor; on the other hand, it ensures that the cavity of the motor body and the cavity of the reducer are connected, and the heat of the stator and rotor in the motor body can be transferred to the cavity of the reducer. This increases the heat dissipation space, and the rotation of the rotor components and the planetary gears can also drive airflow, which can improve the heat dissipation volume and flow rate, thereby improving the heat dissipation efficiency.

[0032] 6. The rotor has a first-stage sun gear and a bearing housing for mounting the support bearing is formed between the rotor and the first-stage planetary carrier, which compensates for the lack of support from the stator support and makes the concentricity between the first-stage reducer and the motor body high.

[0033] 7. By using injection molding to integrally mold the gear ring and the housing, the introduction of a locking part between the gear ring and the housing is eliminated, which compensates for the heat dissipation space, saves costs, reduces the weight and axial dimension of the hub motor, and meets the requirements for lightweight hub motors.

[0034] 8. The first drive unit of the first one-way actuator is connected to the secondary planetary carrier on the reducer via injection molding, eliminating the need for mounting brackets and reducing installation space. Furthermore, the absence of locking components simplifies the installation process and reduces the space required, resulting in a compact hub motor structure that meets lightweight requirements. The first driven unit of the first one-way actuator engages with the mounting base via a spline, ensuring multi-point and uniform circumferential force distribution on the driven unit. This prevents misalignment of the first drive unit and driven unit in the circumferential direction, which would affect their meshing action. Additionally, the spline structure guides the driven unit as it is pushed away from or closer to the first drive unit axially. Moreover, no additional auxiliary structures are needed to fix the driven unit to the mounting base, further reducing installation space and cost, resulting in a more compact hub motor structure.

[0035] 9. By placing the PCB circuit board inside the hub, and integrating all the wires on the PCB circuit board, which can then be directly led out via pins, this replaces the existing technology where the circuit board is externally placed on the frame, requiring multiple wires to be led out of the hub, resulting in a messy and complex process. Moving some functions of the motor controller to the terminal block optimizes the spatial layout of the motor controller and makes better use of the motor's spatial structure. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the hub motor structure;

[0037] Figure 2 This is a cross-sectional view of the hub motor;

[0038] Figure 3 This is a cross-sectional view of a hub motor according to an embodiment of the present invention;

[0039] Figure 4 This is a cross-sectional view of a hub motor according to another embodiment of the present invention;

[0040] Figure 5 Exploded views of the stator and reducer;

[0041] Figure 6 This is a schematic diagram of the hub ring structure;

[0042] Figure 7 Schematic diagram of the hub motor section Figure 1 ;

[0043] Figure 8 Schematic diagram of the hub motor section Figure 2 ;

[0044] Figure 9 This is a structural schematic diagram of the stator component;

[0045] Figure 10 This is a schematic diagram of the stator core structure;

[0046] Figure 11 This is a schematic diagram of a single-tooth iron core.

[0047] Figure 12 This is a schematic diagram of the rotor core structure;

[0048] Figure 13 This is a schematic diagram of the structure of the iron core lamination;

[0049] Figure 14 Explosion of the hub motor section Figure 1 ;

[0050] Figure 15 Explosion of the hub motor section Figure 2 ;

[0051] Figure 16 Explosion of the hub motor section Figure 3 ;

[0052] Figure 17 Explosion of the hub motor section Figure 4 ;

[0053] Figure 18 This is a partial exploded view of the hub motor;

[0054] Figure 19 This is a schematic diagram of the external terminals;

[0055] Figure 20 This is an exploded view of part of the hub motor structure;

[0056] Figure 21 This is a schematic diagram of the control unit.

[0057] Figure 22 This is an exploded view of the control unit;

[0058] Figure 23 This is a schematic diagram of the matrix structure.

[0059] 100. Central shaft; 200. Motor body; 210. Rotor component; 213. Rotor support; 214. First bearing; 215. Rotor body; 211. Support bearing; 212. Bearing housing; 240. Rotor core; 241. Core lamination; 242. Magnet slot; 243. Weight removal hole; 244. Shaft hole; 245. Notch; 220. Stator component; 221. Stator core; 222. Single-tooth core; 223. Yoke; 224. Recess; 225. Protrusion; 226. Tooth body; 227. Tooth section; 228. Stator winding; 230. Stator support; 231. Clearance space; 232. Second end face; 233. Mounting block; 234. Limiting block; 235. First end face; 300. Reducer; 301. First-stage sun gear; 302. First-stage planetary carrier; 303. Gear ring; 304. First-stage planetary gear; 305. Second-stage sun gear; 306. Second-stage planetary gear; 307. Second-stage planetary carrier; 308. Protrusion; 400. Hub ring ; 401, Heat dissipation blade; 410, First one-way valve; 411, First drive unit; 414, First wedge-shaped serration; 412, First driven unit; 415, Second wedge-shaped serration; 416, Second spline; 413, Elastic element; 420, Tower base; 430, Second bearing; 440, Second one-way valve; 490, Sealed cavity; 491, Mounting base; 492, First spline; 500, Control unit; 510, PCB circuit board; 511, Mounting hole; 520 521. Lead-out terminal; 522. Pin; 523. Input terminal; 530. Output terminal; 531. Base; 532. Injection groove; 533. Injection hole; 534. Through hole; 535. Positioning groove; 536. Connecting protrusion; 540. Weight reduction groove; 590. Injection molded part; 591. Power line; 592. Signal line; 593. External terminal; 594. Positioning protrusion; X. First path; Y. Second path; W. Third path; W1. First branch; W2. Second branch. Detailed Implementation

[0060] The following detailed, non-limiting description of the invention's technical solutions, in conjunction with preferred embodiments and accompanying drawings, is provided. In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0061] like Figures 1-8 As shown, an embodiment of the present invention discloses a hub motor for a cycling device, comprising a bottom bracket 100, a motor body 200, a reducer 300, a hub 400, and a chainring (not shown). The motor body 200 and the reducer 300 are mounted on the bottom bracket 100. The hub 400 has a sealed cavity 490, within which the motor body 200 is located. The reducer 300 is located within the sealed cavity 490 and is connected to the motor body 200 in a transmission manner. The bottom bracket 100 passes through the hub 400, and a chainring is mounted on one end of the bottom bracket located outside the hub 400. In this application, the motor body 200 can drive the reducer 300 to rotate the hub 400, or the chainring can rotate the hub 400 under the drive of pedaling force.

[0062] like Figure 5 As shown, the motor body 200 includes a rotor 210, a stator 220, and a stator support 230. The rotor 210 is coaxially mounted on the central shaft 100, the stator 220 is mounted on the rotor 210, and the stator support 230 is wrapped around the stator 220. The stator support 230 is integrally formed by injection molding. The stator support 230 is replaced by PPS or modified nylon instead of the existing aluminum material, which reduces the weight and meets the requirements of lightweight design.

[0063] The reducer 300 includes a planetary carrier and a gear ring 303, which are integrally formed with the stator support 230 by injection molding. Notably, support bearings 211 are provided at both ends of the planetary carrier to ensure that the reducer 300 can operate normally under the drive of the rotor component 210. In one possible embodiment, a bearing chamber 212 for mounting the support bearings 211 is formed between the outer wall of the output portion of the rotor component 210 and the planetary carrier.

[0064] By injection molding the stator bracket 230 and gear ring 303 into a single piece, the stator bracket 230 no longer needs to form a support end face, thus reducing the axial installation size of the motor. In addition, it can ensure the concentricity between the stator bracket 230 and gear ring 303, avoiding the disadvantage of low concentricity caused by separate installation. Furthermore, there is no need to introduce an installation structure, and therefore no need to consider the space occupied by the installation structure, reducing the installation space of the motor and simplifying the process.

[0065] Combination Figure 8 The axial mounting dimensions of the motor are small. Specifically, the end face of the stator bracket 230 facing the reducer 300 is the first end face 235. A toothed groove is formed on the inner wall of the gear ring 303, with the left end of the groove facing the first end face 235. In one feasible embodiment, the left end of the groove extends axially to the first end face 235. In the injection molding process, the supporting end face of the stator bracket 230 facing the gear ring 303 does not need to be designed, and the axial mounting dimension reduction is at least equal to the thickness of the supporting end face.

[0066] Combination Figure 2 A support bearing 211 is axially positioned between the right end face of the rotor support 213 and the left end face of the planetary carrier. In one feasible embodiment, the support end face that must have been provided on the stator support is replaced by a structure on the planetary carrier. This eliminates the need for designing the support end face of the stator support 230 facing the gear ring 303, reducing the axial installation dimension by at least the thickness of the support end face. Furthermore, in this embodiment, the end face of the support bearing 211 facing the motor body 200 extends axially beyond the first end face 235 into the cavity of the motor body 200, further reducing the axial installation dimension.

[0067] See Figure 6 Multiple heat dissipation blades 401 are formed on the inner sidewall of the hub 400. Specifically, the heat dissipation blades 401 can be rib-shaped and / or arc-shaped impeller-shaped, and the multiple heat dissipation blades 401 are evenly distributed circumferentially. The left end of the heat dissipation blade 401 is located near the left sidewall of the hub 400 or extends directly to the left sidewall, and its overall length extends along the axial direction to correspond to the stator component 220 of the motor body 200. In one possible implementation, the heat dissipation blades 401 and the hub 400 can be integrally injection molded.

[0068] As the heat dissipation blades 401 rotate synchronously with the hub ring 400, they cause airflow within the sealed cavity 490 of the hub motor to form a closed-loop airflow circuit. The airflow path in this closed-loop circuit is at least partially formed by the inner wall of the hub ring 400. During the rotation of the hub ring 400, the heat dissipation blades 401 direct the concentrated heat dissipation airflow from the stator and rotor to other areas, allowing the hot airflow to act on various parts of the inner wall of the hub ring 400, thereby increasing the heat dissipation area and efficiency. Compared to existing technologies that rely on air inlets and outlets for air exchange, this application effectively solves the waterproofing problem.

[0069] In one embodiment of the present invention, in order to facilitate a smoother closed-loop airflow circuit, a through hole is provided between the end of the motor body 200 away from the reducer 300 and the hub 400, as shown in the reference. Figure 2 and Figure 3 A through hole is provided at the left end of the motor body 200. The closed-loop airflow circuit includes a first path X or a second path that runs in the opposite direction to the first path X. Under the action of the heat dissipation blades 401, when the airflow moves along the first path X, the airflow first moves to the left along the inner wall of the hub 400, and after turning at the left side wall of the hub 400, it moves to the through hole. It enters from the through hole and passes through the internal cavity of the motor body 200 and the internal cavity of the reducer 300 in sequence. After exiting the internal cavity of the reducer 300, the air pressure at the heat dissipation blades 401 is relatively low, and the airflow moves along the inner wall of the hub 400 to the heat dissipation blades 401, repeating the cycle. In another embodiment of the present invention, refer to Figure 2 and Figure 4No through hole is provided between the end of the motor body 200 away from the reducer 300 and the hub 400. The closed-loop airflow circuit includes a third path W. Under the action of the heat dissipation blades 401, when the airflow moves along the third path W, the airflow first moves to the left side of the motor body 200 while adhering to the inner wall of the hub 400. After the left side of the hub 400 changes direction, the airflow fills the gap formed between the left side of the hub 400 and the left side of the motor body 200. When the airflow is obstructed, it flows back to the heat dissipation blades 401. At this time, the airflow is stratified. The returning airflow adheres to one side of the motor body 200 and continues to flow. The airflow reaches the right end of the reducer 300 and flows along the first branch W1 and the second branch W2 at the right end of the reducer 300. When the airflow flows along the first branch W1, it moves along the outside of the reducer 300 to the right side wall of the hub 400. After reversing at the right side wall of the hub 400, it flows back along the inner wall of the hub 400 to the heat dissipation fins 401. When the airflow flows along the second branch W2, it is blocked after passing through the internal cavity of the reducer 300 and the internal cavity of the motor body 200, flows back to the outside of the reducer 300, and merges with the airflow on the first branch W1. The first branch W1 concentrates the heat in a larger area while continuously contacting the side wall and end face of the hub 400, thereby accelerating the heat dissipation efficiency. Furthermore, when the airflow flows rapidly along the first branch W1, a negative pressure is formed at the end 310 of the reducer 300. This creates a certain suction force on the airflow flowing into the cavity along the second branch W2, ensuring smooth flow in the overall circuit and accelerating heat dissipation. Additionally, the outer side of the end 310 of the reducer 300 is connected to the cavity of the hub 400, meaning that the inner and outer cavities of the motor body 200 are interconnected. Based on the airflow, heat can be effectively transferred out and onto the hub 400, improving heat dissipation.

[0070] like Figure 3 As shown, the distance between the inner wall of the hub 400 and the outer peripheral wall of the reducer 300 is relatively small, which can accelerate the airflow and improve the heat dissipation effect. In this embodiment, the distance d1 between the inner wall of the hub 400 and the outer peripheral wall of the motor body 200 is 3-4mm, while the distance d between the inner wall of the hub 400 and the outer peripheral wall of the reducer 300 is 0.5-1.5mm. The smaller distance can accelerate the airflow and improve the heat dissipation effect.

[0071] Combination Figure 5 and Figure 6 Multiple heat dissipation blades 401 are circumferentially and evenly distributed on the inner wall of the hub 400. The stator support 230 forms a clearance space 231 corresponding to the position of the heat dissipation blades 401, and the heat dissipation blades 401 are at least partially accommodated in the clearance space 231. The clearance space 231 is formed by completely or partially omitting the thickness of the stator support 230 in the radial direction.

[0072] like Figures 9-13 As shown, the stator component 220 includes a stator core 221. The stator core 221 adopts a spliced ​​design, specifically composed of several single-tooth cores 222. The splicing point of adjacent stator cores 221 is located at the yoke 223 of the single-tooth core 222. One of the yokes 223 forms a protrusion 225, and the corresponding part of the other adjacent yoke 223 forms a recess 224. The protrusion 225 is press-fitted into the recess 224 to form the splicing of two adjacent stator cores 221. In addition, by combining the injection molding process, the stator bracket 230 is wrapped around the stator component 220, which can better ensure the strength of the stator component 220 after splicing, and does not increase the length of the tooth 227, thus meeting the characteristics of compact structure and small size, and thus also meeting the design characteristics of the entire motor being compact and small.

[0073] In this application, the concave and convex portions 225 can be semi-circular, V-shaped, serrated, or other shapes. It is also worth noting that the joint between the concave portion 224 and the convex portion 225 can be fixed using methods such as glue or welding.

[0074] The stator core 221 is composed of several single-tooth cores 222 forming a ring.

[0075] like Figure 11 As shown, the single-tooth core 222 also includes a tooth body 226 and a tooth portion 227 extending radially. The tooth body 226 is connected between the yoke portion 223 and the tooth portion 227, and the tooth portion 227 is located on the side of the yoke portion 223 near the axis of the stator core 221.

[0076] like Figure 9 As shown, the stator component 220 also includes a stator winding 228, which is wound on the tooth body 226, with the ratio of its radial winding length to the length of the tooth body 226 being 0.85-0.98. Several single-tooth iron cores 222 wound with the stator winding 228 are spliced ​​together by the yoke 223 of the single-tooth iron cores 222. When the user installs the stator component 220, the stator winding 228 is wound on a single tooth body 226, and then several stator iron cores 221 are spliced ​​together to form the stator component 220. During the winding process, the space on both sides of the tooth body 226 is completely released, unlike full-circle winding which requires a certain amount of clearance for the winding machinery. Therefore, the splicing method designed in this application reduces the gap between two adjacent single-tooth iron cores 222 after splicing to 2-3 mm, effectively increasing the slot fill factor by 8% without changing the space.

[0077] like Figure 2 and Figure 5 As shown, the rotor component 210 includes a rotor body 215 and a rotor support 213, with the rotor body 215 sleeved on the outer peripheral wall of the rotor support 213.

[0078] like Figure 12 As shown, the rotor body 215 includes a rotor core 240 formed by rotating and stacking several core laminations 241. Using a rotating method for stamping and stacking reduces the self-balance of the rotor body 215 and saves time on the production line's dynamic balancing process. (During stamping, one side of the core laminations 241 may be too large or too small. If they are stacked directly in one direction circumferentially, it will cause the entire rotor body 215 to shift on one side, resulting in excessive dynamic balance on one side. However, this rotating method ensures that each core lamination 241 is at a certain angle to the previous one, and any defective parts will also shift. After one rotation, the defective parts will be evenly distributed around the circumference. This method ensures that the balance at every point in the circumference of the rotor body 215 is basically consistent, and the overall dynamic balance is reduced.)

[0079] like Figure 13 As shown, the iron core lamination 241 has multiple magnetic slots 242, which are distributed at intervals along the circumference of the iron core lamination 241.

[0080] The tooth 227 is chamfered on the side facing the rotor 210, and the outer circumferential surface of the rotor core 240 is also chamfered. The purpose is to optimize the magnetic flux density waveform of the air gap between the rotor and stator, so that the overall magnetic flux density waveform tends to be sinusoidal, thereby effectively improving efficiency and reducing noise.

[0081] Multiple weight-reduction holes 243 are also provided on the iron core lamination 241. Weight-reduction holes 243 are also provided between adjacent magnet slots 242, and are located close to the outer edge of the iron core lamination 241. During the rotation of the rotor 210, the centrifugal force at the outer edge is large. The appropriate weight-reduction holes 243 can effectively reduce the centrifugal force, thereby reducing rotor sway and vibration, reducing noise, and ensuring stability. The dimensions of adjacent magnet slots 242 near the outer edge are relatively large, making a larger weight-reduction hole 243 design more suitable. Furthermore, the multiple weight-reduction holes 243 reduce material usage, lower costs, and reduce weight. The radial symmetrical arrangement of the weight-reduction holes 243 with respect to the rotor ensures that the weight on both sides is approximately consistent, guaranteeing stability during motor rotation and reducing sway and vibration.

[0082] Multiple notches 245 are provided in the shaft hole 244 of the core lamination 241. After the multiple core laminations 241 are stacked to form the rotor core 240, the projection of the notch 245 of at least one core lamination 241 in the axial direction does not overlap with (or is at least partially offset) the notch 245 of any other core lamination 241. In this embodiment, by providing notches 245 in the shaft hole 244 of the core laminations 241, the notches 245 can be staggered in the axial direction of the rotor support 213 and stacked, and then connected to the rotor support 213 by an interference fit. This allows the defects of the notches 245 caused by process reasons to be evenly distributed in the circumferential direction of the rotor support 213, thereby avoiding the concentration of defects in the notches. The rotor core provided by the present invention, by providing notches 245 in the shaft hole 244 and staggering the notches 245 during stacking, reduces or eliminates the problem of runout after the rotor support 213 is pressed into the rotor core due to the notches.

[0083] like Figure 5 and Figure 7 As shown, in order to reduce weight and cost, the stator bracket 230 is partially or completely hollowed out at the position corresponding to the stator core 221 (corresponding to the aforementioned clearance space 231). This partially or completely hollowed-out area can also accommodate at least some of the heat dissipation blades 401, thereby reducing the radial dimension of the hub motor.

[0084] like Figure 7 As shown, the end face of the stator bracket 230 facing away from the reducer 300 is the second end face 232, and the second end face 232 of the stator bracket 230 is injection molded in a covering shape. Specifically, the left end face of the stator bracket 230 is injection molded in a covering shape.

[0085] like Figure 8 As shown, the end face of the stator bracket 230 facing the reducer 300 is completely hollowed out, eliminating the need for the original support end face for bearing installation and reducing the axial dimension of the hub motor.

[0086] like Figure 2 , Figure 14 and Figure 15 As shown, the reducer 300 includes a first-stage sun gear 301 and a first-stage planetary carrier 302, with the first-stage sun gear 301 integrated on the output section of the rotor 210.

[0087] Specifically, the rotor component 210 includes a rotor support 213, a primary sun gear 301 integrated on the rotor support 213, and a bearing housing 212 formed between the rotor support 213 and the planetary carrier. In this embodiment, the planetary carrier includes a primary planetary carrier 302 and a secondary planetary carrier 307. Specifically, the bearing housing 212 is formed between the rotor support 213 and the primary planetary carrier 302. This compensates for the lack of a stator support and ensures a high degree of concentricity between the primary reduction gear of the reducer 300 and the motor body 200. In addition, a support bearing 211 is provided between the rotor support 213 and the primary planetary carrier 302, and a support bearing 211 is also provided between the secondary planetary carrier 307 and the central shaft 100, so as to rotatably connect the rotor component 210 and the reducer 300 to the central shaft 100.

[0088] Furthermore, at least one first bearing 214 is provided between the rotor support 213 and the central shaft 100, allowing the rotor support 213 to rotate relative to the central shaft 100. A first-stage sun gear 301 is formed at one end of the rotor support 213 near the reducer 300, and a bearing housing 212 is formed between the rotor support 213 and the first-stage planetary carrier 302. In one possible implementation, the first-stage planetary carrier 302 has multiple protrusions 308 formed on the side facing the rotor component 210, with at least one protrusion 308 between two first-stage planetary gears 304. This protrusion 308 is located on the outer side of the rotor support 213 and, together with the rotor support 213, forms a corresponding bearing housing 212.

[0089] The rotor component 210 also includes a rotor body 215 that mates with the outer peripheral surface of the rotor support 213. The axial length of the rotor body 215 is less than the axial length of the stator component 220, and the radial projection of the aforementioned protrusion 305 is at least partially located on the stator component 220. By reducing the end face of the stator support 230 towards the reducer 300, on the one hand, the first-stage planetary carrier 302 of the reducer 300 can extend into the gap between the rotor component 210 and the stator component 220, eliminating the need for stator support and thus reducing the axial dimension of the hub motor, while ensuring the stability of each component of the reducer 300 during transmission; on the other hand, it ensures that the cavity of the motor body 200 and the cavity of the reducer 300 are connected. During operation, the heat generated by the stator and rotor in the motor body 200 can be transferred to the cavity of the reducer 300, which increases the heat dissipation space and, with the rotation of the rotor component 210 and the planetary gears, also drives airflow, improving the heat dissipation volume and flow rate, thereby improving heat dissipation efficiency.

[0090] The reducer 300 also includes a gear ring 303, which is integrally formed with the stator support 230 by injection molding. This eliminates the need for a locking part between the gear ring 303 and the stator support 230, thus compensating for the heat dissipation space, saving costs, reducing the weight and axial dimension of the hub motor, and meeting the requirements for lightweight hub motors.

[0091] The reducer 300 also includes a first-stage planetary gear 304, which is rotatably mounted on a first-stage planetary carrier 302 and meshes with both a first-stage sun gear 301 and a ring gear 303. It is worth noting that the first-stage planetary carrier 302 must effectively ensure stable meshing between the first-stage planetary gear 304 and the ring gear 303. In the prior art, the first-stage planetary carrier 304 has protrusions that can be rotatably connected to the reducer 300 housing via bearings to ensure the concentricity of the first-stage planetary carrier 304 during rotation, thereby ensuring stable meshing between the first-stage planetary gear 304 and the ring gear 303. This application, however, transfers the bearing chamber 212, which was originally located on the reducer 300 housing, to the rotor component 210. While maintaining stability, this also eliminates the need for the introduction of a left-side housing in the reducer 300, further reducing the axial dimension of the hub motor.

[0092] The reducer 300 also includes a secondary sun gear 305, a secondary planet gear 306, and a secondary planet carrier 307. The secondary sun gear 305 is integrally formed on the side of the primary planet carrier 302 away from the primary planet gear 304. The secondary planet gear 306 is rotatably mounted on the secondary planet carrier 307, and the secondary planet gear 306 meshes with both the secondary sun gear 305 and the gear ring 303.

[0093] A first one-way valve 410 is provided between the output end of the secondary planetary carrier 307 and the hub 400. The motor body 200 can drive the reducer 300 to rotate, and then drive the hub 400 to rotate through the first one-way valve 410. During this process, the first one-way valve 410 is in a locked state.

[0094] The first-stage planetary carrier 302, the first-stage planetary gear 304, the second-stage planetary gear 306, and the second-stage planetary carrier 307 are all made of plastic.

[0095] like Figure 2 , Figure 15 , Figure 16 and Figure 17As shown, the first one-way reducer 410 includes a first driving part 411, a first driven part 412, and an elastic element 413. The first driving part 411 is integrally formed with the output end of the reducer 300 by injection molding. The first driven part 412 is sleeved on the mounting base 491 integrally formed with the hub 400. One end of the elastic element 413 abuts against the hub 400, and the other end abuts against the first driven part 412. When the first driving part 411 rotates counterclockwise, the first one-way reducer 410 is defined as a locked state. The first driving part 411 and the first driven part 412 mesh with each other and rotate synchronously. The reducer 300 drives the motor body 200... The output torque is transmitted to the first drive unit 411, which drives the first driven unit 412 to rotate synchronously. The first driven unit 412 drives the hub 400 to rotate synchronously. When the first drive unit 411 rotates clockwise, the elastic element 413 is compressed, and the first one-way valve 410 is defined as unlocked. The first drive unit 411 and the first driven unit 412 cannot engage. Under the action of the first drive unit 411, the first driven unit 412 intermittently moves away from the first drive unit 411 along the axial direction of the elastic element 413. The first one-way valve 410 cannot transmit the output torque of the motor body 200 to the hub 400. The first drive unit 411 is connected to the secondary planetary carrier 307 on the reducer 300 by injection molding, eliminating the need for a mounting bracket and reducing the installation space. Furthermore, the absence of a locking component reduces the installation space and simplifies the installation process, making the hub motor structure compact and meeting the requirements for lightweight design.

[0096] like Figure 17 As shown, the first driving part 411 has a first wedge-shaped sawtooth 414 formed on the side facing the first driven part 412, and the first driven part 412 has a second wedge-shaped sawtooth 415 formed on the side facing the first driving part 411. When the first one-way device 410 is in the locked state, the first wedge-shaped sawtooth 414 and the second wedge-shaped sawtooth 415 mesh with each other.

[0097] like Figure 16As shown, the mounting base 491 has a first spline 492 around its outer periphery, and the inner ring of the first driven part 412 has a second spline 416. Multiple first splines 492 and second splines 416 are provided and staggered. The sidewalls of adjacent first splines 492 form grooves that mate with the second splines 416. The first driven part 412 engages circumferentially through the first splines 492 and second splines 416. When the first one-way valve 410 is locked, the circumferential limiting of the spline structure can drive the hub 400 to rotate circumferentially. Furthermore, by providing the splines, the first driven part 412 experiences force at multiple points, resulting in uniform circumferential force and preventing misalignment of the first driving part 411 and the first driven part 412 in the circumferential direction, which would affect their meshing action. Additionally, the spline structure acts as a guide as the first driven part 412 is pushed away from or closer to the first driving part 411 in the axial direction. Since no additional auxiliary structure is needed to fix the first driven part 412 and the mounting base 491, the installation space is reduced, the cost is lowered, and the hub motor structure is made more compact. Therefore, in this embodiment, neither the first drive part 411 nor the first driven part 412 of the first one-way valve 410 needs to be fixed by an additional auxiliary structure, which improves the reliability of the entire first one-way valve 410 structure.

[0098] like Figure 2 and Figure 15 As shown, the hub motor also includes a freehub base 420, which is connected to the bottom bracket 100 via at least one second bearing 430. The chainring is fitted onto the outer circumference of the freehub base 420, and a second one-way valve 440 is provided between the freehub base 420 and the hub 400. The user can drive the chainring to rotate by pedaling, which in turn drives the freehub base 420 to rotate synchronously. The freehub base 420, through the second one-way valve 440, drives the hub 400 to rotate. At this time, the second one-way valve 430 is in a locked state, and the first one-way valve 410 is in an unlocked state. It is worth noting that during riding, the states of the first one-way valve 410 and the second one-way valve 430 are always different.

[0099] like Figures 18-23 As shown, the hub motor also includes a control unit 500. The control unit 500 includes a PCB circuit board 510 and lead-out terminals 520. The PCB circuit board 510 is located inside the hub ring 400, and the power line 590 and signal line 591 inside the hub motor are integrated onto the PCB circuit board 510. The input end of the lead-out terminal 520 is connected to the PCB circuit board 510, and the output end is connected to the external terminal 592.

[0100] In one embodiment, the lead-out terminal 520 includes multiple sockets, the input end of which is connected to the PCB circuit board 510, and the output end of which is used to connect to the external terminal 592.

[0101] In another embodiment, the lead-out terminal 520 includes multiple pins 521. The input end 522 of the pins 521 interfaces with the PCB circuit board 510, and the output end 523 of the pins 521 is exposed on the outside of the hub 400 for interface with external terminals 592. By placing the PCB circuit board 510 inside the hub 400, and integrating all the wires on the PCB circuit board 510, and then directly leading them out through the pins 521, this replaces the prior art where the circuit board is externally placed on the frame, requiring multiple wires to be led out from the hub, which is messy and complex. Moving some functions of the motor controller to the terminal board optimizes the spatial layout of the motor controller and makes reasonable use of the space structure of the motor.

[0102] like Figure 22 As shown, the lead-out terminal 520 also includes a base 530 and an injection molded part 540, the injection molded part 540 being used to fix the pin 521 onto the base 530.

[0103] like Figure 23 As shown, the base 530 has an injection groove 531 and multiple injection holes 532. The injection holes 532 are circumferentially distributed and extend axially to ensure the precision of injection molding of the injection molded part 540. Multiple pins 521 correspond one-to-one with the multiple injection holes 532. The pins 521 pass through the injection holes 532, and both the input end 522 and the output end 523 of the pins 521 are exposed on the outside of the base 530 and the injection molded part 540. By setting the injection groove 531 and injection holes 532, the precise molding of the injection molded part 540 and the precise docking of the pins 521 can be ensured. Even with long-term use, the probability of bending of the pins 521 is very small, resulting in a long service life. In actual manufacturing, the base 530 and the pins 521 need to be placed in a mold and injection molded as a single piece, which simplifies the fixing process. The substrate 530 is made of aluminum alloy ADC12 or powder metallurgy die casting to reduce weight and achieve lightweight design. The pin 521 is made of gold-plated copper to ensure efficient connection. The injection molded part 540 is made of flame-retardant nylon or other related insulating materials.

[0104] The axial ends of the injection molded part 540 do not extend beyond the axial ends of the base 530, so as to avoid the injection molded part 540 affecting the axial installation direction of the base 530.

[0105] The base 530 has a through hole 533 that mates with the central shaft 100.

[0106] A positioning groove 534 is provided on the outer side wall of the base 530, and a positioning protrusion 593 that mates with the positioning groove 534 is provided on the external terminal 592, which facilitates positioning and prevents the external terminal 592 from rotating relative to the base 530.

[0107] A connecting protrusion 535 is also provided on the outer side wall of the base 530, and the connecting protrusion 535 is fixedly connected to the stator bracket 230 on the motor body 200.

[0108] Multiple weight-reducing grooves 536 are provided on the connecting protrusion 535 to meet the lightweight design requirements. The multiple weight-reducing grooves 536 are evenly distributed circumferentially on the connecting protrusion 535.

[0109] The PCB circuit board 510 is ring-shaped and fixed on the stator bracket 230 of the motor body 200. The ring-shaped design of the PCB circuit board 510 allows the UVW three-phase lines of the stator to be directly electrically connected to the PCB circuit board 510 without the need for wires to be led out to a specific connection point, using the shortest distance "nearest principle". This ring-shaped design makes the installation process and wiring more convenient and efficient.

[0110] The power cord 590 of the motor body 200 is inserted into the PCB circuit board 510 along the axial direction and is electrically connected to the PCB circuit board 510.

[0111] like Figure 20 As shown, the stator bracket 230 has a mounting block 233 protruding in the axial direction, and the PCB circuit board 510 has a mounting hole 511, forming an inner wall of the mounting hole 511 that fits against the outer side of the mounting block 233.

[0112] like Figure 20 As shown, the stator bracket 230 has a limiting block 234 protruding in the axial direction. The PCB circuit board 510 is at least partially in contact with the end face of the limiting block 234 to ensure that the position of the PCB circuit board 510 will not tilt after installation.

[0113] The ratio of the axial projected area of ​​the mating part of the PCB circuit board 510 and the limiting block 234 to the axial projected area of ​​the PCB circuit board 510 is 0.3-0.35.

[0114] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A hub motor for a cycling device, characterized in that, The device includes a central shaft (100), a motor body (200), a reducer (300), a hub (400), and a gear sprocket. The motor body (200) and the reducer (300) are housed in the cavity of the hub (400) and respectively fitted onto the central shaft (100). The central shaft (100) passes through the hub (400), and the gear sprocket is fitted onto one end of the central shaft located outside the hub (400). The motor body (200) drives the reducer (300) to rotate the hub (400), or the crankshaft drives the hub (400) to rotate; The motor body (200) includes a rotor (210), a stator (220), and a stator support (230). The rotor (210) is coaxially sleeved on the central shaft (100), the stator (220) is sleeved on the rotor (210), and the stator support (230) is wrapped around the stator (220). The stator support (230) is integrally formed by injection molding. The reducer (300) includes a planetary carrier and a gear ring (303). The gear ring (303) and the stator support (230) are integrally formed by injection molding. Support bearings (211) are provided at both ends of the planetary carrier. A bearing chamber (212) for installing the support bearings (211) is formed between the outer wall of the output shaft of the rotor (210) and the planetary carrier.

2. The hub motor according to claim 1, characterized in that, The planetary carrier has a plurality of protrusions (308) on the side facing the rotor (210), and the protrusions (308) and the rotor (210) together form the corresponding bearing chamber (212).

3. The hub motor according to claim 2, characterized in that, The protrusion (308) is located between two adjacent planetary gears of the reducer (300).

4. The hub motor according to claim 1, characterized in that, The end face of the stator support (230) facing the reducer (300) is the first end face (235), and a tooth groove is formed on the inner sidewall of the gear ring (303), one end of which extends axially to the first end face (235).

5. The hub motor according to claim 4, characterized in that, The support bearing (211) extends axially across the first end face (235) into the cavity of the motor body (200) from the end face facing the motor body (200).

6. The hub motor according to claim 1, characterized in that, The stator component (220) includes a stator core (221), and the stator bracket (230) is partially or completely hollowed out corresponding to the position of the stator core (221).

7. The hub motor according to claim 1, characterized in that, The end face of the stator bracket (230) facing away from the reducer (300) is the second end face (232), which is injection molded in a covering shape.

8. The hub motor according to claim 1, characterized in that, The reducer (300) also includes a first-stage sun gear (301), which is integrated on the output section of the rotor (210).

9. The hub motor according to claim 8, characterized in that, The rotor component (210) includes a rotor support (213) and a rotor body (215) that mates with the outer peripheral surface of the rotor support (213). The first-stage sun gear (301) is integrated on the rotor support (213), and the bearing chamber (212) is formed between the rotor support (213) and the planet carrier.

10. The hub motor according to claim 8, characterized in that, The planetary carrier of the reducer (300) includes a primary planetary carrier (302) and a secondary planetary carrier (307). The reducer (300) also includes a primary planetary gear (304). The primary planetary gear (304) is rotatably mounted on the primary planetary carrier (302), and the primary planetary gear (304) meshes with both the primary sun gear (301) and the ring gear (303). Preferably, the reducer (300) further includes a secondary sun gear (305) and a secondary planetary gear (306). The secondary sun gear (305) is integrally formed on the side of the primary planetary carrier (302) away from the primary planetary gear (304). The secondary planetary gear (306) is rotatably mounted on the secondary planetary carrier (307), and the secondary planetary gear (306) meshes with both the secondary sun gear (305) and the gear ring (303). Preferably, a central shaft (100) is included, through which the motor body (200) and the reducer (300) pass axially. At least one first bearing (214) is provided between the rotor support (213) and the central shaft (100). A support bearing (211) is provided between the rotor support (213) and the first-stage planetary carrier (302). The support bearing (211) is also provided between the second-stage planetary carrier (307) and the central shaft (100), so as to rotatably connect the rotor (210) and the reducer (300) to the central shaft (100). Preferably, a first one-way valve (410) is provided between the output end of the secondary planetary carrier (307) and the hub (400). The motor body (200) can drive the reducer (300) to rotate and then drive the hub (400) to rotate through the first one-way valve (410). At this time, the first one-way valve (410) is in a locked state. Preferably, the hub motor further includes a freehub base (420), which is connected to the bottom bracket (100) via at least one second bearing (430). The chainring is fitted onto the outer circumferential surface of the freehub base (420), and a second one-way valve (440) is provided between the freehub base (420) and the hub (400). The user can drive the chainring to rotate by stepping on the pedal, and the chainring drives the freehub base (420) to rotate synchronously. The freehub base (420) drives the hub (400) to rotate via the second one-way valve (440). At this time, the second one-way valve (430) is in a locked state, and the first one-way valve (410) is in an unlocked state. Preferably, the hub motor further includes a control unit (500), which includes a PCB circuit board (510) and lead-out terminals (520), and the PCB circuit board (510) is disposed inside the hub ring (400). Preferably, the lead-out terminal (520) includes a plurality of pins (521), the input end (522) of the pin (521) is connected to the PCB circuit board (510), and the output end (523) of the pin (521) is exposed outside the hub (400) for connecting to external terminals (592). Preferably, the lead-out terminal (520) includes a plurality of sockets, the input end of which is connected to the PCB circuit board (510), and the output end of which is used to connect to an external terminal (592).

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