Motor

Abstract

The utility model provides an electric machine. The motor includes: a housing defining a chamber therein and having an inner surface facing the chamber and arranged in a circumferential direction; the stator is fixed in the cavity; the rotor is fixed on the inner surface; the rotor is positioned on the radial outer side of the stator; the shell is further provided with a plurality of liquid storage grooves which are recessed from the inner surface and distributed in the circumferential direction, and each liquid storage groove is communicated with the cavity and extends in the axial direction.

Description

Technical Field

[0001] The present disclosure relates to the field of electric drive technology, and more specifically, to a motor that can be used as a wheel hub motor. Background Art

[0002] The wheel hub motor is a motor system that integrates the motor directly into the wheel hub. It achieves the transmission of driving force by placing the motor inside the car wheel hub, and adopts a direct drive mode, that is, the motor is directly connected to the wheel axle of the vehicle, without traditional transmission devices (such as drive shafts, differentials, etc.), so it has the advantages of high integration, high torque, high efficiency and fast response. However, although the wheel hub motor has achieved a high degree of integration, it faces the problem of heat dissipation. One of the existing mainstream heat dissipation solutions for the wheel hub motor is air cooling, that is, the heat dissipation of the wheel hub motor is achieved through air convection with the external environment. The main challenge of the air-cooled motor is that the flow conditions in the air area near the bottom of the stator bracket are close to the natural convection of the air, so the heat dissipation conditions are poor, which makes it difficult for the air-cooled motor to cover all key working conditions, thereby limiting the further improvement of the motor power. Another mainstream heat dissipation solution for the wheel hub motor is oil cooling, that is, the heat dissipation of the wheel hub motor is achieved by cooling the oil. The main challenge of oil-cooled motors is that if the motor speed fluctuates, the cooling oil can be dispersed everywhere due to inertia, but under continuous working conditions, the motor speed remains basically unchanged, which causes the cooling oil to accumulate at the bottom of the housing and cannot be dispersed throughout the motor. If there is no additional structure to disturb the cooling oil, the cooling oil can only cool the lower part of the stator, resulting in poor thermal performance of the upper part of the motor. However, if a disturbing structure such as a blade is set inside the housing, the motor resistance and motor size will increase.

[0003] Therefore, in the art, there is an urgent need for a technical solution that can reliably cool the hub motor while avoiding a significant increase in motor resistance and motor size. Utility Model Content

[0004] In order to solve the above-mentioned problems in the prior art, the present disclosure proposes an improved motor, which includes: a shell, which defines a chamber internally and has an inner surface facing the chamber and arranged circumferentially; a stator fixed in the chamber; and a rotor fixed on the inner surface, the rotor being located radially outside the stator; wherein the shell is also provided with a plurality of liquid storage tanks recessed from the inner surface and distributed circumferentially, each liquid storage tank being connected to the chamber and extending axially.

[0005] According to an optional embodiment of the present disclosure, the motor further includes a main shaft extending through the housing, the housing is rotatably supported on the main shaft, and the stator is fixed on the main shaft.

[0006] According to an alternative embodiment of the present disclosure, a coolant is provided in the chamber.

[0007] According to an alternative embodiment of the present disclosure, the motor further includes a stator bracket, and the stator is fixed to the main shaft through the stator bracket.

[0008] According to an alternative embodiment of the present disclosure, the housing includes a housing body that circumferentially surrounds the main shaft and two end caps connected to both axial ends of the housing body. The plurality of liquid storage grooves are provided in the housing body, and the main shaft extends through the two end caps.

[0009] According to an alternative embodiment of the present disclosure, each liquid storage groove axially extends through the housing body such that both axial ends of each liquid storage groove are defined by the two end caps.

[0010] According to an alternative embodiment of the present disclosure, each end cap is provided with a bearing configured to cooperate with the main shaft.

[0011] According to an alternative embodiment of the present disclosure, both axial ends of each liquid storage groove are located on both sides of the stator such that each liquid storage groove communicates with the chamber on both sides of the stator.

[0012] According to an alternative embodiment of the present disclosure, the rotor includes a plurality of permanent magnets fixed on the inner surface and circumferentially distributed. The plurality of permanent magnets are circumferentially spaced apart from the plurality of liquid storage grooves.

[0013] According to an alternative embodiment of the present disclosure, the plurality of permanent magnets and the plurality of liquid storage grooves are circumferentially arranged alternately.

[0014] According to an alternative embodiment of the present disclosure, the motor further includes a plurality of positioning blocks. Each positioning block is inserted into a liquid storage groove and protrudes from the liquid storage groove such that each positioning block is connected to two adjacent permanent magnets.

[0015] According to an alternative embodiment of the present disclosure, the positioning block is spaced apart from the bottom of the liquid storage groove and is also spaced apart from both axial ends of the liquid storage groove.

[0016] According to an alternative embodiment of the present disclosure, the distance that the positioning block protrudes from the liquid storage groove is less than the thickness of the permanent magnet.

[0017] According to an alternative embodiment of the present disclosure, the motor is a hub motor, and the motor further includes a bead seat, which is attached to the housing and is configured for mounting a tire.

[0018] The present disclosure may be embodied in the schematic embodiments in the accompanying drawings. However, it should be noted that the drawings are merely schematic, and any variations contemplated under the teachings of the present disclosure should be considered to be included within the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings illustrate exemplary embodiments of the present disclosure. These drawings should not be construed as necessarily limiting the scope of the present disclosure, wherein:

[0020] Figure 1 is a schematic front view of an electric machine according to one embodiment of the present disclosure;

[0021] Figure 2 is along Figure 1 a schematic three-dimensional cross-sectional view of the electric machine taken along line II-II in

[0022] Figure 3 is along Figure 1 a schematic cross-sectional view of the electric machine taken along line III-III in

[0023] Figure 4 is along Figure 3 a schematic cross-sectional view of the electric machine taken along line IV-IV in DETAILED DESCRIPTION

[0024] Further features and advantages of the present disclosure will become more apparent from the following description with reference to the accompanying drawings. The accompanying drawings illustrate exemplary embodiments of the present disclosure, and the various drawings are not necessarily drawn to actual scale. However, the present disclosure may be implemented in many different forms and should not be construed as necessarily limited to the exemplary embodiments disclosed herein. Instead, these exemplary embodiments are provided only to illustrate the present disclosure and to convey the spirit and essence of the present disclosure to those skilled in the art.

[0025] The present disclosure aims to provide an outer rotor motor with a novel design. The novel design according to the present disclosure enables the coolant inside the motor to be evenly distributed throughout the entire internal space of the motor. In particular, it can reliably transport the coolant accumulated at the bottom of the motor housing to the top of the motor housing, thereby enabling the coolant to cool not only the part of the motor stator immersed in the coolant but also the part of the motor stator not immersed in the coolant, thus improving the heat dissipation of the entire motor stator, which provides the possibility for further increasing the motor power. In particular, since the novel design according to the present disclosure can evenly distribute the coolant throughout the entire internal space of the motor, compared with the existing technical solutions that store a large amount of coolant inside the motor to improve the stator heat dissipation, the novel design according to the present disclosure allows reducing the coolant stored in the motor, thereby reducing the resistance exerted by the coolant on the rotor and improving the efficiency of the motor. Additionally, compared with the existing technical solutions that set disturbing vanes inside the motor housing, the novel design according to the present disclosure can also avoid exerting a large resistance on the rotor due to transporting the coolant, thereby further improving the efficiency of the motor and avoiding increasing the size of the motor. In summary, the novel design of the motor according to the present disclosure can not only significantly improve the heat dissipation of the entire stator but also reliably maintain the efficiency of the motor.

[0026] The following will describe in detail various optional but non-limiting embodiments of the motor according to the present disclosure with reference to the accompanying drawings. It should be noted that the terms "axial / axial direction", "radial / radial direction", and "circumferential / circumferential direction / circular direction" indicating directions used herein have their ordinary meanings in the art. Specifically, "axial" refers to the direction coinciding with or parallel to the axis of the motor main shaft (i.e., the rotation axis of the motor rotor), "radial" refers to the direction perpendicular to the axis of the motor main shaft, and "circumferential" refers to the direction surrounding the axis of the motor main shaft.

[0027] Reference Figures 1 - 3 , in which, Figure 1 FIG. shows a schematic front view of a motor according to an embodiment of the present disclosure, Figure 2 FIG. shows a schematic three-dimensional cross-sectional view of the motor taken along line II-II in Figure 1 , and Figure 3 FIG. shows a schematic cross-sectional view of the motor taken along line III-III in Figure 1 . As shown in Figures 1 - 3 , the motor 10 generally includes a housing 100 and a bead seat 20 fixed on the housing 100. Among them, the housing 100 is configured to drive the bead seat 20 to rotate, and the bead seat 20 is configured to mount and fix a tire so that the motor 10 can be used as a hub motor for driving the tire to rotate.

[0028] As shown inFigure 2 and Figure 3 As shown, in addition to the housing 100, the electric machine 10 generally includes a stator 200 and a rotor 300 accommodated in the housing 100 and a main shaft 400 extending through the housing 100. Among them, the housing 100 is rotatable relative to the main shaft 400, the stator 200 is fixed on the main shaft 400, and the rotor 300 is fixed on the housing 100 and located radially outside the stator 200. And among them, the main shaft 400 defines the rotation axis XX' of the housing 100 and the rotor 300. Therefore, different from the traditional electric machine in which the housing and the stator remain fixed but the rotor and the main shaft are rotatable, in the electric machine 10 according to the present disclosure, the stator 200 and the main shaft 400 will remain stationary or fixed, while the housing 100 and the rotor 300 can rotate relative to the stator 200 and the main shaft 400 around the rotation axis XX' when the electric machine 10 is powered on, thereby enabling other components (such as the bead seat 20 and the tire) to be driven to rotate by the housing 100. In particular, a bearing can be provided between the housing 100 and the main shaft 400, that is to say, the main shaft 400 is coupled or connected to the housing 100 through the bearing, so that the housing 100 can be rotatably supported on the main shaft 400 through the bearing. In particular, the electric machine 10 further includes a stator bracket 500 which is connected to the stator 200 on the radial outside and connected to the main shaft 400 on the radial inside, so as to fixedly support the stator 200 on the main shaft 400.

[0029] As Figure 2 and Figure 3As shown in the enlarged partial view, the housing 100 includes a generally annular housing body (also referred to as an annular body) 110 and two end caps 120 connected to both ends of the housing body 110. Among them, the housing body 110 is arranged to surround the main shaft 400 in the circumferential direction, that is, to surround the rotation axis XX' in the circumferential direction, so that both ends of the housing body 110 are separated from each other in the axial direction, and thus the two end caps 120 are opposite to each other in the axial direction. In addition, the two end caps 120 and the housing body 110 jointly define a chamber 101 located inside the housing 100. Among them, the stator 200 and the rotor 300 are both accommodated in the chamber 101, and the main shaft 400 extends through the chamber 101 and extends through the two end caps 120. In particular, a bearing that can cooperate with the main shaft 400 can be provided on each end cap 120, so that the housing 100 can be reliably supported on the main shaft 400 in a rotatable manner through the bearings on each end cap 120. In particular, the two end caps 120 are both spaced apart from the stator 200, the rotor 300, and the stator support 500 in the axial direction, so that the chamber 101 has two chamber portions 101' located on the opposite sides of the stator 200, the rotor 300, and the stator support 500 in the axial direction. In other words, the chamber 101 is separated by the stator 200, the rotor 300, and the stator support 500 into two chamber portions 101' located on the opposite sides of it in the axial direction, and the two chamber portions 101' can be fluidly connected to each other through the liquid storage tank detailed below.

[0030] The stator 200 includes a generally annular stator core 210 and a stator winding 220 attached to the stator core 210. The stator core 210 is arranged to surround the main shaft 400 in the circumferential direction, that is, to surround the rotation axis XX' in the circumferential direction, and is fixedly supported on the main shaft 400 by a stator bracket 500. In addition, the stator core 210 is further provided with a plurality of winding slots 211 distributed in the circumferential direction (i.e., separated from each other in the circumferential direction) and a plurality of stator teeth 212 also distributed in the circumferential direction (i.e., separated from each other in the circumferential direction). Among them, each winding slot 211 extends through the stator core 210 in the axial direction, each stator tooth 212 protrudes outward from the stator core 210 in the radial direction, and each winding slot 211 is defined between two adjacent stator teeth 212 and is used to receive or allow a plurality of wires of the stator winding 220 to pass through, whereby the stator winding 220 is attached to the stator core 210, and the arrangement of each wire of the stator winding 220 is such that these wires will generate a rotating magnetic field rotating around the rotation axis XX' after being energized with alternating current. In particular, if the motor 10 is configured as a round wire motor, then the stator winding 220 is composed of round wires, and these round wires can be wound around the stator teeth 212 through the winding slots 211; if the motor 10 is configured as a flat wire motor, then the stator winding 220 is composed of flat wires, and these flat wires can be directly inserted into the winding slots 211 in the axial direction without having to be wound around the stator teeth 212. Therefore, the specific type of the motor cannot constitute a limitation on the protection scope of the present disclosure, and any specific type of motor adopting the teachings of the present disclosure falls within the protection scope of the present disclosure.

[0031] Reference Figure 4 , in which a schematic cross-sectional view of the motor taken along Figure 3 the line IV-IV in is shown, and for the sake of clarity, the main shaft and the stator of the motor have been omitted. As Figure 3 and Figure 4 shown, the housing body 110 has an inner surface 111 and an outer surface 112 opposite to each other in the radial direction, wherein both the inner surface 111 and the outer surface 112 are arranged to surround the main shaft 400 (i.e., surround the rotation axis XX') in the circumferential direction, and the inner surface 111 faces the inside of the housing 100, that is, faces the radial inner side, while the outer surface 112 faces the outside of the housing 100, that is, faces the radial outer side, and is particularly used to connect the bead seat 20. In Figure 3 and Figure 4In the illustrated embodiment, the bead seat 20 and the housing body 110 are two separate components, and the bead seat 20 can be connected to the outer surface 112 of the housing body 110 by means of welding, threaded connection, etc. Of course, in other embodiments, the bead seat 20 and the housing body 110 can be integrally formed by casting, 3D printing, machining, etc., so that the two form an integral component. As Figure 4 As shown in Figure 4 and its partial enlarged view, the rotor 300 includes a plurality of permanent magnets 310 attached (e.g., by welding, bonding, etc.) to the inner surface 111 of the housing body 110 and distributed along the circumferential direction (i.e., separated from each other along the circumferential direction). Each permanent magnet 310 is generally in the shape of a cuboid and is spaced apart from the stator core 210 in the radial direction, so as to form an air gap for magnetic flux to pass through between each permanent magnet 310 and the stator core 210.

[0032] Under the above configuration, the main shaft 400 can be fixed to, for example, the frame or chassis of an automobile, so that the main shaft 400 and the stator 200 fixedly supported by the main shaft 400 are fixed relative to the automobile. Then, alternating current can be supplied to the stator winding 220 of the stator 200 to generate a rotating magnetic field that rotates around the rotation axis XX'. This rotating magnetic field will be coupled with each permanent magnet 310 of the rotor 300, so as to drive each permanent magnet 310 to rotate around the rotation axis XX'. Each permanent magnet 310 will drive the housing 100 to rotate around the rotation axis XX' together, and the housing 100 will drive the bead seat 20 and the tire attached to the bead seat 20 to rotate around the rotation axis XX' together. Thus, the rotation of the tire is driven by the motor 10. However, during the operation of the motor 10, the alternating current in the stator winding 220 and the eddy currents generated in the stator core 210 and the housing body 110 due to the rotating magnetic field will cause a part of the electrical energy to be converted into heat energy, and this heat energy will increase with the increase of the power of the motor 10.

[0033] In order to effectively dissipate the heat energy generated during the operation of the motor 10, so as to provide the possibility for further increasing the power of the motor 10, as Figure 3 and Figure 4 As shown, a coolant CL is stored in the housing 100 (i.e., in the chamber 101). However, in order to avoid excessive weight of the motor 10 and excessive resistance during the rotation of the housing 100, the coolant CL does not fill the entire chamber 101, but only occupies a part of the chamber 101. This makes it so that during the operation of the motor 10, since the motor 10 is arranged such that the main shaft 400 (i.e., the rotation axis XX') is oriented in the horizontal direction (as Figure 3 and Figure 4As shown, the coolant CL will accumulate at the bottom of the chamber 101, so that the bottom part of the stator 200 is immersed in the coolant CL, while the upper part of the stator 200 is exposed from the coolant CL. To cool the upper part of the stator 200, the housing body 110 is provided with a plurality of liquid storage grooves 113 that are recessed from its inner surface 111 in the radial direction and distributed in the circumferential direction (i.e., separated from each other in the circumferential direction). Each liquid storage groove 113 extends in the axial direction and is in fluid communication with the chamber 101.

[0034] In the above configuration, during the operation of the motor 10, the housing body 110 will rotate around the rotation axis XX' together with each permanent magnet 310. This enables each permanent magnet 310 and each part of the housing body 110 to cycle through the coolant stored at the bottom of the chamber 101, so that each permanent magnet 310 and each part of the housing body 110 can be cooled. At the same time, each liquid storage groove 113 will also cycle through the coolant. When the liquid storage groove 113 is immersed in the coolant, since the liquid storage groove 113 is in fluid communication with the chamber 101, the coolant in the chamber 101 can enter the liquid storage groove 113. The coolant that enters the liquid storage groove 113 will rotate upward together with the liquid storage groove 113. After the liquid storage groove 113 rotates to the upper side, the coolant will be discharged from the liquid storage groove 113 under the action of its own gravity, thereby cooling the upper part of the stator 200. That is to say, during the operation of the motor 10, each liquid storage groove 113 can cyclically store the coolant near the bottom of the stator 200 and discharge the coolant near the top of the stator 200, so that the coolant is distributed throughout the chamber 101. Thus, reliable heat dissipation of the housing 100, the stator 200, and the rotor 300 can be achieved. In particular, the heat dissipation of the upper part of the stator 200 can be significantly improved. Therefore, the configuration according to the present disclosure can not only reliably cool the housing and the rotor of the motor, but also reliably cool the entire stator, thereby providing the possibility for further increasing the power of the motor. It is also worth mentioning that the above configuration also makes it possible to reliably cool the entire stator 200 without storing a large amount of coolant in the chamber 101, and there is no need to provide blades for disturbing the coolant on the housing body 110 and the end cover 120 (these blades may cause a significant increase in the rotational resistance of the housing). Therefore, the above configuration also helps to reduce the weight of the motor 10 and the resistance to the rotation of the housing 100, thereby maintaining the efficiency of the motor 10.

[0035] In an alternative embodiment of the present disclosure, as Figure 3As shown in it and its partial enlarged view, the liquid storage tank 113 has two ends 113' that are opposite or separated in the axial direction, that is to say, the liquid storage tank 113 extends from one end 113' thereof along the axial direction to the other end 113'. In particular, the length of the liquid storage tank 113 in the axial direction is greater than the length of the stator core 210 in the axial direction, and the stator core 210 is arranged such that the two ends 113' of the liquid storage tank 113 are located on opposite sides of the stator core 210 along the axial direction, so that the liquid storage tank 113 can be in fluid communication with the chamber 101 on both sides of the stator core 210. In other words, the liquid storage tank 113 can be in fluid communication with a chamber portion 101' on each side of the stator core 210. In this configuration, the coolant in the chamber 101 (i.e., each chamber portion 101') can enter and exit the liquid storage tank 113 from both sides of the stator core 210, which enables the coolant to fill the liquid storage tank 113 and be discharged from the liquid storage tank 113 more quickly and smoothly. Thereby, it can be ensured that even when the housing 100 rotates at a high speed, a sufficient amount of coolant can be stored in the liquid storage tank 113 for cooling the upper part of the stator 200. Therefore, the above configuration further improves the heat dissipation of the upper part of the stator 200. In particular, the liquid storage tank 113 extends through the housing body 110 in the axial direction, so that the two ends 113' of the liquid storage tank 113 are respectively defined by two end caps 120, which can reduce the processing difficulty of the liquid storage tank 113, thereby avoiding a significant increase in the manufacturing cost of the motor 10 due to the processing of the liquid storage tank 113.

[0036] In an alternative embodiment of the present disclosure, as Figure 4 As shown in it and its partial enlarged view, the liquid storage tank 113 and the permanent magnets 310 are alternately arranged in the circumferential direction, that is to say, the number of the liquid storage tanks 113 is the same as the number of the permanent magnets 310, and each liquid storage tank 113 is located between two adjacent permanent magnets 310. In other words, each permanent magnet 310 is located between two adjacent liquid storage tanks 113. Thereby, the number of the liquid storage tanks 113 can be maximized to further improve the heat dissipation of the upper part of the stator 200 without affecting the reliable positioning of the permanent magnets 310.

[0037] In an alternative embodiment of the present disclosure, as Figure 3 and Figure 4As shown, the motor 10 further includes a plurality of positioning blocks 600 distributed along the circumferential direction (i.e., separated from each other along the circumferential direction). Each positioning block 600 is inserted into a liquid storage groove 113 and protrudes from the liquid storage groove 113. That is to say, each positioning block 600 has a part located in the liquid storage groove 113 and a part located outside the liquid storage groove 113. In this configuration, each positioning block 600 is located between two adjacent permanent magnets 310. In other words, each permanent magnet 310 is located between two adjacent positioning blocks 600. In addition, each positioning block 600 is connected to the housing body 110 in the liquid storage groove 113 and is connected to two adjacent permanent magnets 310 outside the liquid storage groove 113. In this configuration, each permanent magnet 310 is not only held by the inner surface 111 of the housing body 110 in the radial direction, but also held by two adjacent positioning blocks 600 in the circumferential direction. Thus, each permanent magnet 310 can be positioned more reliably, which helps to improve the reliability of the motor 10. In particular, as Figure 3 shown in its partial enlarged view, each positioning block 600 is spaced apart from both ends 113' of the liquid storage groove 113 along the axial direction and is spaced apart from the bottom of the liquid storage groove 113 along the radial direction, thereby forming a space for accommodating the coolant and a channel for the coolant to flow through. In this configuration, the positioning block 600 does not interfere with the coolant entering the liquid storage groove 113, but will interfere with the coolant discharging from the liquid storage groove 113 to a certain extent. However, this interference is beneficial because it can prevent the coolant from discharging prematurely from the liquid storage groove 113. For example, it can prevent the coolant from discharging when the liquid storage groove 113 just rotates past the middle part of the stator 200, and such premature discharge of the coolant may cause the top part of the stator 200 not to be effectively cooled. Therefore, in the above configuration, the positioning block 600 can not only promote the reliable positioning of the permanent magnet 310, but also ensure that the liquid storage groove 113 can transport the coolant to the vicinity of the top of the stator 200, thereby further improving the heat dissipation of the upper part of the stator 200. In particular, as Figure 4 shown in its partial enlarged view, the distance D by which each positioning block 600 protrudes from the liquid storage groove 113 is less than the thickness T of the permanent magnet 310 measured along the radial direction. Thus, it can be avoided that the positioning block 600 protrudes into the air gap between the permanent magnet 310 and the stator core 210, thereby avoiding the interference of the magnetic flux in the air gap, which also helps to improve the reliability of the motor 10.

[0038] The optional but non-limiting embodiments of the electric machine according to the present disclosure have been described in detail with reference to the accompanying drawings. For those ordinary skilled in the art, modifications and supplements to the technology and structure, as well as the recombination of features in each embodiment, should clearly be regarded as being included within the scope of the present disclosure without departing from the spirit and essence of the present disclosure. Therefore, these modifications and supplements that can be envisioned under the teaching of the present disclosure should be regarded as part of the present disclosure. The scope of the present disclosure includes equivalent technologies known at the filing date of the present disclosure application and equivalent technologies not yet foreseen.

Claims

1. An electric motor, characterized in that, The motor (10) includes: A housing (100) that defines an internal chamber (101) therein and has an inner surface (111) facing the chamber (101) and arranged circumferentially; A stator (200) fixed within the chamber (101); and A rotor (300) fixed on the inner surface (111), the rotor (300) being located radially outside the stator (200); Wherein, the housing (100) is further provided with a plurality of liquid storage grooves (113) recessed from the inner surface (111) and distributed circumferentially, and each liquid storage groove (113) communicates with the chamber (101) and extends axially.

2. The motor according to claim 1, characterized in that, The motor (10) further includes a main shaft (400) extending through the housing (100), the housing (100) being rotatably supported on the main shaft (400), and the stator (200) being fixed on the main shaft (400).

3. The motor according to claim 1, characterized in that, Coolant is provided within the chamber (101).

4. The motor according to claim 2, characterized in that, The motor (10) further includes a stator bracket (500), and the stator (200) is fixed on the main shaft (400) through the stator bracket (500).

5. The motor according to claim 2, wherein The housing (100) includes a housing body (110) circumferentially surrounding the main shaft (400) and two end caps (120) connected to the two axial ends of the housing body (110), the plurality of liquid storage grooves (113) are provided in the housing body (110), and the main shaft (400) extends through the two end caps (120).

6. The motor according to claim 5, characterized in that, Each liquid storage groove (113) extends axially through the housing body (110) such that the two axial ends (113’) of each liquid storage groove (113) are defined by the two end caps (120).

7. The motor according to claim 5, characterized in that, Each end cap (120) is provided with a bearing configured to cooperate with the main shaft (400).

8. The motor according to any one of claims 1-7, characterized in that, The two axial ends (113’) of each liquid storage groove (113) are located on both sides of the stator (200) such that each liquid storage groove (113) communicates with the chamber (101) on both sides of the stator (200).

9. The electric machine according to any one of claims 1-7, characterized in that, The rotor (300) includes a plurality of permanent magnets (310) fixed on the inner surface (111) and distributed circumferentially, and the plurality of permanent magnets (310) are circumferentially spaced apart from the plurality of liquid storage grooves (113).

10. The motor according to claim 9, characterized in that, The plurality of permanent magnets (310) and the plurality of liquid storage grooves (113) are arranged circumferentially and alternately.

11. The motor according to claim 10, characterized in that, The motor (10) further includes a plurality of positioning blocks (600), and each positioning block (600) is inserted into a liquid storage groove (113) and protrudes from the liquid storage groove (113) such that each positioning block (600) is connected to two adjacent permanent magnets (310).

12. The motor according to claim 11, characterized in that, The positioning block (600) is spaced apart from the bottom of the liquid storage groove (113) and is also spaced apart from the two axial ends (113’) of the liquid storage groove (113).

13. The motor according to claim 11, characterized in that, The distance (D) by which the positioning block (600) protrudes from the liquid storage groove (113) is less than the thickness (T) of the permanent magnet (310).

14. The motor according to any one of claims 1-7, characterized in that, The motor (10) is a hub motor, and the motor (10) further includes a bead seat (20), which is attached to the housing (100) and configured to mount a tire.

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