Wheel hub motor and electric vehicle

Abstract

The application discloses a kind of wheel hub motor and electric vehicle, wheel hub motor includes middle shaft and is connected to the shell assembly of middle shaft, stator assembly, rotor assembly and gear assembly, shell assembly and rotor assembly are supported on the middle shaft by bearing, shell assembly has main shell, wherein, rotor assembly is transmission connection with shell assembly by gear assembly, rotor assembly is provided with the first baffle ring towards main shell, main shell is provided with the second baffle ring towards rotor assembly, along the axial direction of middle shaft, first baffle ring and second baffle ring are at least partially staggered, and the grease chamber is formed between rotor assembly and main shell, and gear assembly is located in the grease chamber.The surface of gear assembly is coated with grease, the first baffle ring of rotor assembly and the second baffle ring of main shell are staggered in the axial direction, which can prevent the grease from being thrown out of the grease chamber, the grease is left in the grease chamber, the lubrication effect is improved, the reliability problems such as wear and failure of the gear assembly are avoided, and the operation reliability of the wheel hub motor is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric machines, in particular to a wheel hub motor and an electric vehicle. BACKGROUND

[0002] In the related art, a direct-drive outer rotor wheel hub motor is an integrated structure of an outer rotor and a rim. One of the reasons why a wheel hub motor with a gear reducer has not been used in large quantities on electric vehicles is that the gear reducer is at high risk of gear wear and failure due to poor lubrication. The main influencing factor of poor lubrication is insufficient or ineffective lubricating grease, resulting in poor reliability of the wheel hub motor with the gear reducer. SUMMARY

[0003] The present application aims to at least solve one of the technical problems in the prior art. To this end, the present application provides a wheel hub motor that can improve lubrication and improve the reliability of the wheel hub motor.

[0004] The present application also provides an electric vehicle with the above wheel hub motor.

[0005] According to the wheel hub motor of the first aspect of the present application, the wheel hub motor comprises a middle shaft, a housing assembly, a stator assembly, a rotor assembly and a gear assembly connected to the middle shaft. The housing assembly and the rotor assembly are supported on the middle shaft by bearings. The housing assembly has a main housing. The rotor assembly is drivingly connected to the housing assembly through the gear assembly. The rotor assembly is provided with a first retainer ring facing the main housing. The main housing is provided with a second retainer ring facing the rotor assembly. In the axial direction of the middle shaft, the first retainer ring and the second retainer ring are at least partially staggered. A grease chamber is formed between the rotor assembly and the main housing. The gear assembly is located in the grease chamber.

[0006] According to the wheel hub motor of the first aspect of the present application, the rotor assembly of the wheel hub motor drives the housing assembly to rotate through the gear assembly. The housing assembly is connected to the wheels of the electric vehicle to realize the driving of the electric vehicle. The gear assembly is located in the grease chamber. The surface of the gear assembly is coated with a large amount of lubricating grease. The first retainer ring of the rotor assembly and the second retainer ring of the main housing are staggered in the axial direction, which can prevent the lubricating grease from being thrown out of the grease chamber. The lubricating grease stays in the grease chamber to lubricate the gear assembly, improving the lubrication effect and avoiding reliability problems such as wear and failure of the gear assembly, thereby improving the operational reliability of the wheel hub motor.

[0007] According to some embodiments of the first aspect of the present application, in the axial direction of the middle shaft, the length of the first retainer ring and the second retainer ring is L, and L satisfies L≥0.1mm.

[0008] According to some embodiments of the first aspect of the present application, the second retaining ring is located between the first retaining ring and the middle shaft along a radial direction of the middle shaft.

[0009] According to some embodiments of the first aspect of the present application, an inner wall diameter of the first retaining ring is D1, and an outer wall diameter of the second retaining ring is D2, satisfying 1mm≤D1-D2≤4mm.

[0010] According to some embodiments of the first aspect of the present application, the first retaining ring is located between the second retaining ring and the middle shaft along a radial direction of the middle shaft.

[0011] According to some embodiments of the first aspect of the present application, the first retaining ring is provided with a receiving groove facing an end surface of the main housing, and part of the second retaining ring is located in the receiving groove.

[0012] According to some embodiments of the first aspect of the present application, the rotor assembly comprises a rotor plastic package, a bearing seat, a magnetic yoke and a permanent magnet, the rotor plastic package wraps the magnetic yoke and the permanent magnet, the bearing seat and the rotor plastic package are in an integral molding structure, and the first retaining ring is arranged on the rotor plastic package.

[0013] According to some embodiments of the first aspect of the present application, the rotor plastic package is provided with a plurality of circumferentially distributed heat dissipation blades, and the heat dissipation blades face the stator assembly.

[0014] According to some embodiments of the first aspect of the present application, the rotor plastic package is provided with a plurality of circumferentially distributed flow guide holes, and the flow guide holes are located between two adjacent heat dissipation blades.

[0015] According to some embodiments of the first aspect of the present application, a plurality of the flow guide holes are arranged on an outer side of the first retaining ring.

[0016] According to some embodiments of the first aspect of the present application, the stator assembly comprises a stator core and a winding, the stator core has a closed yoke portion, an outer periphery of the yoke portion is provided with a plurality of tooth portions, the winding is wound on the tooth portions, and the winding corresponds to positions of the flow guide holes along a radial direction of the middle shaft.

[0017] According to some embodiments of the first aspect of the present application, the tooth portions are provided as straight teeth.

[0018] According to some embodiments of the first aspect of the present application, the tooth portions are provided as toothless shoe structures, the stator core is connected with a limiting frame, and the limiting frame is used to limit a radial position of the winding relative to the tooth portions.

[0019] According to some embodiments of the first aspect of the present application, the limiting frame comprises a mounting portion and a limiting portion, the mounting portion is connected with the stator assembly, the limiting portion corresponds to the tooth portion one by one, the limiting portion comprises two fork rods, the distance between the two fork rods is matched with the width of the tooth portion, and the fork rods abut against the outer ends of the windings.

[0020] According to the second aspect of the present application, the electric vehicle comprises the wheel hub motor of the first aspect.

[0021] Additional aspects and advantages of the present application will be given, partially in the following description, partially become obvious from the following description, or be understood by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0022] Additional aspects and advantages of the present application will become apparent and easily understood by the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0023] Figure 1 is a sectional view of the wheel hub motor in some embodiments of the present application;

[0024] Figure 2 is Figure 1 a local enlarged view at A in the middle;

[0025] Figure 3 is a local view of the cooperation of the first stop ring and the second stop ring in some embodiments of the present application; Figure 1 ;

[0026] Figure 4 is a local view of the cooperation of the first stop ring and the second stop ring in some embodiments of the present application; Figure 2 ;

[0027] Figure 5 is an exploded schematic view of the wheel hub motor in some embodiments of the present application;

[0028] Figure 6 is a structural schematic view of the rotor assembly in some embodiments of the present application; Figure 1 ;

[0029] Figure 7 is a structural schematic view of the rotor assembly in some embodiments of the present application; Figure 2 ;

[0030] Figure 8 is an exploded schematic view of the rotor assembly in some embodiments of the present application;

[0031] Figure 9 is a structural schematic view of the stator core and the winding in some embodiments of the present application;

[0032] Figure 10 is a structural schematic view of the limiting frame in some embodiments of the present application.

[0033] The reference signs are as follows:

[0034] Central shaft 100, bearing 110;

[0035] Housing assembly 200, grease chamber 201, main housing 210, second blocking ring 211, auxiliary housing 220, rim 230;

[0036] Stator assembly 300, winding 310, stator core 320, tooth portion 321, limiting frame 330, fork rod 331;

[0037] Rotor assembly 400, rotor plastic package 410, rotor plastic package 410, first blocking ring 411, accommodating groove 4111, heat dissipation fan blade 412, inner sleeve 413, flow guide hole 414, bearing seat 420, magnetic yoke 430, permanent magnet 440;

[0038] Gear assembly 500, sun gear 510, planet gear 520, planet carrier 530, outer ring gear 540. DETAILED DESCRIPTION

[0039] The embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.

[0040] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as a limitation of the present application. The device or element indicated is not required to have a particular orientation, and is not required to be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0041] In the description of the present application, if the first, second, etc. are described, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the sequence of technical features indicated.

[0042] In the description of the present application, unless otherwise explicitly limited, the words such as setting, installing, connecting, etc. should be broadly understood, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0043] In the related art, the electric vehicle adopts a wheel hub motor as a power component, the outer rotor of the wheel hub motor and the rim are in an integrated structure, and the wheel hub motor pursues integration of a power system, a transmission system and a brake system in design, some wheel hub motors are provided with a gear reducer, the gear high-speed rotation is easy to throw away the lubricating grease, resulting in insufficient lubricating grease on the gear surface, one of the reasons why such wheel hub motors cannot be used in large quantities is that the gear reducer has a high risk of gear wear and failure due to poor lubrication, thereby the wheel hub motor with the gear reducer has poor reliability, affecting the driving stability of the electric vehicle.

[0044] As shown in Figures 1 to 4 , the embodiment of the first aspect of the application proposes a wheel hub motor applied to an electric vehicle, the wheel hub motor comprises a middle shaft 100 and a shell assembly 200, a stator assembly 300, a rotor assembly 400 and a gear assembly 500 connected to the middle shaft 100, the middle shaft 100 is connected to the frame of the electric vehicle and serves as a mounting base, the shell assembly 200 comprises a main shell 210, an auxiliary shell 220 and a rim 230, the main shell 210 and the auxiliary shell 220 are separately arranged at two ends of the rim 230, the main shell 210 and the auxiliary shell 220 are fixedly connected at the two ends of the rim 230 by screws, three bearings 110 are installed on the middle shaft 100, the main shell 210, the auxiliary shell 220 and the rotor assembly 400 are respectively connected to one bearing 110 and can rotate relative to the middle shaft 100.

[0045] Referring to Figure 1 and Figure 5 , the gear assembly 500 comprises a sun gear 510, three planetary gears 520, a planet carrier 530 and an outer ring gear 540, the sun gear 510 is fixedly connected to the rotor assembly 400, the planet carrier 530 is fixedly connected to the middle shaft 100, the three planetary gears 520 are rotatably connected to the planet carrier 530, the outer ring gear 540 is fixedly connected to the main shell 210, the planetary gears 520 are simultaneously engaged with the sun gear 510 and the outer ring gear 540, the rotor assembly 400 drives the sun gear 510 to rotate, the sun gear 510 drives the three planetary gears 520 to rotate, the three planetary gears 520 further drive the outer ring gear 540 and the main shell 210 to rotate, the main shell 210 drives the rim 230 to rotate, the rim 230 belongs to the wheel of the electric vehicle, therefore the wheel hub motor directly drives the wheel to rotate, realizing the driving of the electric vehicle. In addition, the planetary gear 520 is a double planetary gear, two-stage transmission reduction is realized through the planetary gear 520, the rotation speed of the rim 230 is reduced, the output torque of the wheel hub motor is improved, which is beneficial to the speed-up of the electric vehicle.

[0046] It can be understood that the gear assembly 500 is located between the rotor assembly 400 and the main housing 210, so that the rotor assembly 400 and the main housing 210 cooperate to form a grease chamber 201, and the gear assembly 500 is arranged in the grease chamber 201. The grease chamber 201 can accommodate the gear assembly 500 on the one hand, prevent the gear assembly 500 from being exposed, and accommodate the lubricating grease on the other hand, so that the surfaces of the sun gear 510, the three planetary gears 520 and the outer ring 540 can be coated with the lubricating grease, sufficient lubrication is provided, and wear is reduced.

[0047] It can be understood that considering that when the sun gear 510 and the three planetary gears 520 rotate at high speed, the lubricating grease will be thrown off due to the centrifugal force, resulting in insufficient lubrication, the first retaining ring 411 is arranged on the rotor assembly 400, the second retaining ring 211 is arranged on the main housing 210, the first retaining ring 411 faces the main housing 210, the second retaining ring 211 faces the rotor assembly 400, the first retaining ring 411 and the second retaining ring 211 form the side wall of the grease chamber 201, and the function of preventing the lubricating grease from leaking out is achieved. In the axial direction of the shaft 100, the first retaining ring 411 and the second retaining ring 211 are staggered, can block the lubricating grease thrown off, and can make the lubricating grease stay in the grease chamber 201, so that the gear assembly 500 has sufficient lubrication. In the radial direction of the shaft 100, the first retaining ring 411 and the second retaining ring 211 are close to each other and do not contact, and do not affect the independent rotation of the rotor assembly 400 and the main housing 210.

[0048] When the wheel hub motor operates, the stator assembly 300 of the wheel hub motor drives the rotor assembly 400 to rotate through electromagnetic force, the rotor assembly 400 drives the housing assembly 200 to rotate through the gear assembly 500, the housing assembly 200 drives the wheels of the electric vehicle to rotate through the rim 230, and the driving of the electric vehicle is realized. The gear assembly 500 is located in the grease chamber 201 between the rotor assembly 400 and the main housing 210, the lubricating grease is stored in the grease chamber 201, the lubricating grease is coated on the surface of the gear assembly 500 to provide lubrication, the first retaining ring 411 of the rotor assembly 400 and the second retaining ring 211 of the main housing 210 are staggered in the axial direction, forming a blocking structure, which can prevent the lubricating grease from being thrown out of the grease chamber 201, so that the lubricating grease stays in the grease chamber 201 to lubricate the gear assembly 500, improve the lubrication effect, avoid the gear assembly 500 from being worn and failed due to insufficient lubrication, improve the operation reliability of the wheel hub motor, and improve the use reliability of the electric vehicle.

[0049] Referring to Figure 2It can be understood that, in the axial direction of the shaft 100, the first blocking ring 411 and the second blocking ring 211 are staggered, and the staggered length dimension is defined as L, that is, the length of the overlap of the first blocking ring 411 and the second blocking ring 211, and L is set to be greater than or equal to 0.1 mm. Considering that the first blocking ring 411 and the second blocking ring 211 are not in contact, the staggered length dimension L is set to be greater than or equal to 0.1 mm, so as to form an effective block to prevent the lubricating grease from leaking out of the gap between the first blocking ring 411 and the second blocking ring 211.

[0050] With reference to Figure 2 It can be understood that, in the radial direction of the shaft 100, the first blocking ring 411 is located outside the second blocking ring 211, and the second blocking ring 211 is closer to the shaft 100. After the lubricating grease is thrown away, it first contacts the second blocking ring 211 and then contacts the first blocking ring 411. Moreover, the first blocking ring 411 and the second blocking ring 211 are staggered, which can limit the thrown-away lubricating grease so that the lubricating grease remains in the grease sealing cavity 201.

[0051] With reference to Figure 1 It can be understood that the inner wall diameter of the first blocking ring 411 is defined as D1, and the outer wall diameter of the second blocking ring 211 is defined as D2. Considering that the rotor assembly 400 and the main housing 210 are both high-speed rotating during the operation of the in-wheel motor, and the rotation speeds of the rotor assembly 400 and the main housing 210 are different, D1 and D2 satisfy (D1-D2) / 2≥0.5 mm, so as to ensure that the first blocking ring 411 and the second blocking ring 211 do not rub and collide during rotation. In addition, D1 and D2 satisfy (D1-D2) / 2≤2.0 mm, so as to provide an effective block to facilitate reducing the leakage of lubricating grease from the grease sealing cavity 201. After calculation, it is set to be 1 mm≤D1-D2≤4 mm, so that the gap between the first blocking ring 411 and the second blocking ring 211 can prevent the lubricating grease from leaking away and also can not produce interference friction.

[0052] With reference to Figure 3 It can be understood that, in the radial direction of the shaft 100, the second blocking ring 211 can also be located outside the first blocking ring 411, and the first blocking ring 411 is closer to the shaft 100. After the lubricating grease is thrown away, it first contacts the first blocking ring 411 and then contacts the second blocking ring 211. Moreover, the first blocking ring 411 and the second blocking ring 211 are staggered, which can limit the thrown-away lubricating grease so that the lubricating grease remains in the grease sealing cavity 201.

[0053] With reference to Figure 4It can be understood that the first baffle ring 411 has two side plates, and a containing groove 4111 is formed between the two side plates and located at the end face of the first baffle ring 411 facing the main shell 210. Since the first baffle ring 411 and the second baffle ring 211 are staggered, part of the second baffle ring 211 extends into the containing groove 4111, and the first baffle ring 411 and the second baffle ring 211 cooperatively form a double-layer barrier to more effectively block the lubricating grease thrown away. In addition, part of the second baffle ring 211 extends into the containing groove 4111, and a continuous curved gap is formed between the first baffle ring 411 and the second baffle ring 211, which is similar to a labyrinth seal structure and helps to reduce the probability of lubricating grease leakage.

[0054] With reference to Figures 6 to 8 It can be understood that the main component of the rotor assembly 400 is the rotor plastic package 410, which integrally wraps the magnetic yoke 430 and the permanent magnet 440 through the process of injection molding. Moreover, the bearing seat 420 is also integrally formed with the rotor plastic package 410. The bearing seat 420 is located at the center of the rotor plastic package 410, and the inner wall of the bearing seat 420 forms a bearing chamber to cooperate with the bearing 110. In order to improve the stability of the connection, the outer wall of the bearing seat 420 has a plurality of circumferentially distributed bosses. After injection molding, the bosses are embedded in the rotor plastic package 410, which improves the structural strength and is conducive to the transmission of torque. Considering that the rotor plastic package 410 is an injection molded part, the first baffle ring 411 is arranged on the rotor plastic package 410, which is convenient for manufacturing and reduces the cost. The rotor assembly 400 adopts an integrated structure, and the magnetic yoke 430 and the permanent magnet 440 are fixed by being wrapped by the rotor plastic package 410, which avoids the permanent magnet 440 from falling off and improves the reliability of the rotor assembly 400, thereby being conducive to improving the service life of the hub motor.

[0055] With reference to Figure 1 and Figure 6 It can be understood that the rotor plastic package 410 is provided with a plurality of cooling fan blades 412, which are uniformly distributed along the circumference of the rotor plastic package 410. The rotor plastic package 410 is provided with an inner sleeve 413, and the bearing seat 420 is connected to the inner wall of the inner sleeve 413. The cooling fan blades 412 extend radially from the outer wall of the inner sleeve 413. Inside the hub motor, the cooling fan blades 412 are directed towards the stator assembly 300, and the outer edges of the cooling fan blades 412 are relatively low in height to avoid the windings 310 of the stator assembly 300. When the rotor assembly 400 rotates at a high speed, the airflow is driven to flow by the plurality of cooling fan blades 412, thereby taking away the heat generated by the windings 310, helping to cool down, and preventing the problem of over-temperature shutdown.

[0056] With reference to Figures 6 to 8It can be understood that the rotor plastic package 410 is also provided with a plurality of flow guide holes 414, which are uniformly distributed along the circumference of the rotor plastic package 410, and each flow guide hole 414 is arranged between two adjacent cooling fan blades 412, for example, the flow guide hole 414 can be one-to-one corresponding to the cooling fan blade 412, or the number of flow guide holes 414 can be half of the number of cooling fan blades 412. As shown in Figure 1 When the rotor assembly 400 rotates at high speed, the airflow is driven to flow by the plurality of cooling fan blades 412, and the flow guide hole 414 serves as a channel for the airflow to flow, and connects the two sides of the rotor plastic package 410. The airflow flows into the inner cavity of the housing assembly 200, and the main housing 210 and the auxiliary housing 220 of the housing assembly 200 are metal parts, such as aluminum alloy parts, which have large structural strength and excellent heat transfer performance. The airflow contacts the main housing 210 and the auxiliary housing 220, and dissipates heat to the outside space through the main housing 210 and the auxiliary housing 220. The rotor assembly 400 rotates at high speed, and the airflow circulation loop is formed inside the hub motor by the cooling fan blades 412 and the flow guide holes 414, which improves the air convection capability inside the hub motor, fully removes the heat generated by the winding 310, improves the heat dissipation performance of the hub motor, and reduces the temperature rise of the hub motor, thereby ensuring the stability of the output efficiency of the hub motor and meeting the load operation requirements of the hub motor. In addition, the cooling fan blades 412 also have the function of reinforcing ribs, which improve the overall structural strength and stiffness of the rotor assembly 400 and improve the reliability.

[0057] Referring to Figure 7 It can be understood that the first retaining ring 411 is integrally formed on the rotor plastic package 410, and the plurality of flow guide holes 414 are arranged on the outer side of the first retaining ring 411, so that the airflow flowing through the flow guide hole 414 cannot enter the grease cavity 201, thereby avoiding the influence of the airflow on the lubricating grease. Moreover, the flow guide hole 414 is located at the outer edge of the rotor plastic package 410, and the airflow can quickly flow to contact the main housing 210, which is beneficial to heat dissipation.

[0058] Referring to Figure 9 and Figure 10The stator assembly 300 comprises the winding 310, a stator core 320 and a limiting frame 330, the stator core 320 has a closed yoke part, a plurality of tooth parts 321 are distributed on the outer periphery of the yoke part, and the stator core 320 is generally cut from a silicon steel sheet; the cut silicon steel sheet is processed into a winding type stator core 320; in order to improve the utilization rate of the silicon steel sheet, the material cutting mode needs to be designed in advance during cutting; if the tooth part 321 of the stator core 320 is provided with a tooth shoe, the material cutting mode needs to be designed according to the tooth shoe during cutting of the stator core; however, no matter how optimized, in the case of the tooth shoe, the material utilization rate of the silicon steel sheet can only reach 70% at most, and it is difficult to further improve. The tooth part 321 of the stator core 320 of the embodiment of the present application adopts a tooth part 321 without a tooth shoe, optimizes the material cutting mode, and further improves the material utilization rate of the silicon steel sheet.

[0059] With reference to Figure 1 It can be understood that, in the radial direction of the middle shaft 100, the distance between the winding 310 and the middle shaft 100 is substantially equal to the distance between the flow guide hole 414 and the middle shaft 100, and the positions of the two correspond to each other, so that the heat emitted by the winding 310 is quickly taken away by the airflow passing through the flow guide hole 414, which helps to improve the heat dissipation effect of the winding 310.

[0060] It can be understood that the tooth part 321 is provided in a straight-toothed shape, and the winding 310 does not need to be wound on the tooth part 110, but can be wound outside by using a tool, so that the operation space is large and the slot fill rate can be effectively improved. The winding 310 adopts an aluminum wire with a square cross section, and the cross section of the tooth part 321 is square. The aluminum wire of the winding 310 matches the shape of the tooth part 321, thereby improving the slot fill rate.

[0061] It should be noted that the limiting frame 330 and the stator assembly 300 can be fixedly connected or detachably connected. The fixed connection can be achieved by welding or riveting; the detachable connection can be achieved by using screws or buckle structures, etc. The limiting frame 330 is used to limit the winding 310 instead of the tooth shoe.

[0062] As shown in Figure 10 The limiting frame 330 comprises a mounting part and a limiting part, the mounting part is used to fixedly connect the stator assembly 300, and the limiting part is used to limit the winding 310 in the radial direction. The number of the limiting part is consistent with that of the winding 310, and the positions of the limiting part and the winding 310 correspond to each other. The limiting frame 330 is used to limit the winding 310 instead of the tooth shoe. Each group of limiting parts has two parallel fork rods 331, the spacing between the two fork rods 331 is matched with the width of the tooth part 321, so that the space between the two fork rods 331 can accommodate the tooth part 321. The fork rod 331 abuts against the outer end surface of the winding 310, and two points act on the winding 310, so as to reliably limit and fix the winding 310.

[0063] It should be noted that a connecting rod (not shown in the figure) can also be arranged between the two fork rods 331, the connecting rod is arranged perpendicularly to the fork rods 331, and after assembly, the connecting rod also abuts the outer end surface of the winding 310, helping to define the winding 310, and further improving the reliability.

[0064] The electric vehicle of the second aspect embodiment of the present application comprises the hub motor of the first aspect embodiment, the hub motor comprises a middle shaft 100 and a shell assembly 200 connected to the middle shaft 100, a stator assembly 300, the stator assembly 300 and a gear assembly 500, the gear assembly 500 is located in a grease chamber 201 between the rotor assembly 400 and the main shell 210, the grease chamber 201 is used to accommodate the gear assembly 500 on the one hand, preventing the gear assembly 500 from being exposed, and on the other hand, accommodating the lubricating grease, so that the surfaces of the sun gear 510, the three planetary gears 520 and the outer ring gear 540 can be coated with the lubricating grease, providing sufficient lubrication and reducing wear. A first retaining ring 411 is arranged on the rotor assembly 400, and a second retaining ring 211 is arranged on the main shell 210, the first retaining ring 411 faces the main shell 210, and the second retaining ring 211 faces the rotor assembly 400, the first retaining ring 411 and the second retaining ring 211 form the side wall of the grease chamber 201, preventing the lubricating grease from leaking out, in the axial direction of the middle shaft 100, the first retaining ring 411 and the second retaining ring 211 are arranged alternately, which can block the lubricating grease thrown away, so that the lubricating grease stays in the grease chamber 201 to lubricate the gear assembly 500, improving the lubrication effect, avoiding the gear assembly 500 from being worn out, failing and other reliability problems due to insufficient lubrication, improving the operation reliability of the hub motor and the use reliability of the electric vehicle.

[0065] The embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the present application.

Claims

1. Hub motor, characterized in that: include: central axis; a housing assembly supported on the central shaft via a bearing, the housing assembly comprising a main housing; a stator assembly fixedly connected to the central shaft; a rotor assembly supported on the central shaft via bearings; a gear assembly connected to the central shaft; The rotor assembly is connected to the housing assembly through the gear assembly. The rotor assembly is provided with a first retaining ring facing the main housing, and the main housing is provided with a second retaining ring facing the rotor assembly. Along the axial direction of the central axis, the first retaining ring and the second retaining ring are at least partially staggered. A grease sealing cavity is formed between the rotor assembly and the main housing, and the gear assembly is located in the grease sealing cavity. The rotor assembly is also provided with a plurality of circumferentially evenly distributed heat dissipation blades and a plurality of circumferentially evenly distributed guide holes. An inner sleeve is provided at the center of the rotor assembly. A space for accommodating the heat dissipation blades is provided between the rotor assembly and the windings of the stator assembly. The heat dissipation blades radially extend from the outer wall of the inner sleeve to the outer ring of the rotor assembly. Along the axial direction of the central axis, the heat dissipation blades and the windings of the stator assembly are staggered. A notch is provided on one side edge of the heat dissipation blade facing the winding to avoid the winding; the guide hole is located between two adjacent heat dissipation blades and the guide hole is arranged on the outside of the first retaining ring.

2. The hub motor according to claim 1, characterized in that: Along the axial direction of the central axis, the length dimension of the staggered first retaining ring and the second retaining ring is L, and L≥0.1 mm.

3. The hub motor according to claim 1 or 2, characterized in that: Along the radial direction of the central shaft, the second retaining ring is located between the first retaining ring and the central shaft.

4. The hub motor according to claim 3, characterized in that: The inner wall diameter of the first retaining ring is D1, and the outer wall diameter of the second retaining ring is D2, satisfying 1mm≤(D1-D2)≤4mm.

5. The hub motor according to claim 1 or 2, characterized in that: Along the radial direction of the central shaft, the first retaining ring is located between the second retaining ring and the central shaft.

6. The hub motor according to claim 1 or 2, characterized in that: An accommodating groove is provided on the end surface of the first retaining ring facing the main housing, and a portion of the second retaining ring is located in the accommodating groove.

7. The hub motor according to claim 1, characterized in that: The rotor assembly includes a rotor overmolded part, a bearing seat, a yoke and a permanent magnet. The rotor overmolded part wraps the yoke and the permanent magnet. The bearing seat and the rotor overmolded part are an integrally formed structure. The first retaining ring is arranged on the rotor overmolded part.

8. The hub motor according to claim 7, characterized in that: The heat dissipation blades are arranged on the rotor plastic package.

9. The hub motor according to claim 8, characterized in that: The guide hole is arranged on the rotor plastic package.

10. The hub motor according to claim 9, characterized in that: The stator assembly includes a stator core and a winding. The stator core has a closed yoke. A plurality of teeth are provided on the outer periphery of the yoke. The winding is wound around the teeth. Along the radial direction of the central axis, the winding corresponds to the position of the guide hole.

11. The hub motor according to claim 10, characterized in that: The tooth portion is configured as straight teeth.

12. The hub motor according to claim 11, characterized in that: The tooth portion is a tooth-shoe-free structure, and the stator core is connected to a limiting frame, which is used to limit the radial position of the winding relative to the tooth portion.

13. The hub motor according to claim 12, characterized in that: The limiting frame includes a mounting portion and a limiting portion, the mounting portion is connected to the stator assembly, the limiting portion corresponds one-to-one to the tooth portion, the limiting portion includes two fork rods, the spacing between the two fork rods is adapted to the width of the tooth portion, and the fork rods abut against the outer end of the winding.

14. An electric vehicle, characterized in that: The invention comprises the hub motor according to any one of claims 1 to 13.

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