Electric vehicle hub motor

Abstract

The present invention relates to the technical field of motors for electric vehicles. Specifically, disclosed is an electric vehicle hub motor. An oil inlet pipe is connected to an oil pump; an oil inlet hole connects the oil inlet pipe to the oil pump; an oil outlet hole connects the oil pump to a connection oil passage; the connection oil passage is connected to an annular oil passage; a plurality of oil inlets connected to the annular oil passage are provided in the inner wall of a stator core, the plurality of oil inlets corresponding to a plurality of stator teeth on an one-to-one basis; cooling oil passages connected to the oil inlets are provided in the stator teeth; a plurality of first oil outlets connected to the cooling oil passages are provided in the side walls of the stator teeth. A drive component drives the oil pump to rotate, so as to pump cooling oil into the oil inlet pipe, and the cooling oil enters the oil inlet pipe, enters the oil pump via the oil inlet hole, then is pumped out of the oil outlet hole to enter the connection oil passage and finally enter the annular oil passage, then enters the corresponding cooling oil passages via the plurality of oil inlets, flows through the cooling oil passages and then flows out of the side walls of the stator teeth. Thus, a cooling cycle is executed and a stator can be uniformly cooled.

Description

An electric vehicle hub motor Technical Field

[0001] The present invention relates to the technical field of motors for electric vehicles, and in particular to a hub motor for an electric vehicle. Background Art

[0002] With the development and popularization of transportation, electric two-wheeled vehicles are playing an increasingly important role in people's daily travel. At the same time, with the development of technology and the trend of electrification that is conducive to carbon neutrality, electric two-wheeled vehicles will gradually replace traditional fuel motorcycles.

[0003] As the core component of electric two-wheeled vehicles, the main function of the hub motor is to provide continuous and stable power for the electric vehicle. When riding an electric two-wheeled vehicle, especially when starting, going uphill, or driving with a heavy load, the motor is prone to heating up and may even burn out, seriously affecting its normal operation. Therefore, appropriate measures should be taken to cool the motor.

[0004] The hub motors of existing electric two-wheeled vehicles usually adopt the method of directly adding cooling oil or connecting an external oil pump and cooling the stator winding ends through potting to improve the heat dissipation performance of the motor. When the motor is running at high or extremely low speed, the cooling oil cannot reach the top winding of the motor to cool it, resulting in uneven cooling at the bottom and top. The external oil pump method fixes the oil pipe to the end of the stator winding and then forms an integral whole through potting. However, due to structural limitations, the middle part of the winding coil can only transfer heat to the end through the potting glue, and then cool it through the oil pipe with cooling oil flowing, and its cooling effect is not ideal.

[0005] Summary of the Invention

[0006] The object of the present invention is to provide an electric vehicle hub motor, which can solve the problem of uneven cooling of existing electric vehicle hub motors.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] The present invention provides an electric vehicle hub motor, comprising:

[0009] wheel hub;

[0010] A first end cover and a second end cover, wherein the first end cover, the second end cover and the wheel hub surround and form a receiving cavity, and cooling oil is stored in the receiving cavity;

[0011] a motor shaft, wherein the motor shaft passes through the first end cover and the second end cover;

[0012] and a tube connecting the discharging opening of the oil drain plug, the tube connecting the discharging opening and the oil drain plug, and the like. When the oil drain plug is connected, the oil drain plug is connected to the oil drain plug, and the oil drain plug is connected to the oil drain plug.

[0013] A driving assembly is fixedly connected to the first end cover and is capable of driving the oil pump to rotate.

[0014] As an optimal technical solution for the above-mentioned electric vehicle hub motor, the stator also includes a plurality of winding coils, which are arranged in a one-to-one correspondence with the plurality of stator teeth, and the winding coils are wound around the stator teeth. A cover plate is provided between the winding coils and the end faces of the stator teeth, and the cover plate is made of insulating material. A second oil outlet is provided on the end face of the stator tooth, and the second oil outlet is connected to the cooling oil channel. The cover plate is provided with a plurality of third oil outlets connected to the second oil outlet.

[0015] As an optimal technical solution for the above-mentioned electric vehicle hub motor, the drive assembly includes a driving gear, a driven gear and a rotating shaft. The rotating shaft is used to drive the oil pump to rotate. The driving gear is fixedly connected to the first end cover and meshes with the driven gear. The driven gear is fixedly sleeved on the rotating shaft.

[0016] As an optimal technical solution for the above-mentioned electric vehicle hub motor, the oil pump includes a pump body and pump blades, a pump cavity is provided in the pump body, the pump blades are arranged in the pump cavity and fixedly connected to the rotating shaft, and the oil outlet hole and the oil inlet hole are both provided on the pump body.

[0017] As a preferred technical solution of the above-mentioned electric vehicle hub motor, the end faces of each tooth portion of the driving gear and the driven gear are provided with chamfers.

[0018] As a preferred technical solution of the above-mentioned electric vehicle hub motor, a plurality of grooves are provided on the top of each stator tooth.

[0019] As a preferred technical solution of the above-mentioned electric vehicle hub motor, the electric vehicle hub motor also includes a first bearing, the outer ring of the first bearing is fixedly connected to the first end cover, and the inner ring of the first bearing is fixedly sleeved on the motor shaft.

[0020] As an optimal technical solution for the above-mentioned electric vehicle hub motor, the electric vehicle hub motor also includes a first oil seal, which includes an inner ring body, an outer ring body and a side lip. The inner ring body is sleeved on the motor shaft, and the outer ring body is interference fit with the first end cover and is located between the first end cover and the inner ring body. The side lip is fixedly connected between the inner ring body and the outer ring body.

[0021] As an optimal technical solution for the above-mentioned electric vehicle hub motor, the inner ring body includes a main body and a connecting part, the main body is sleeved on the motor shaft, the main body is provided with a plurality of first serrations, and the plurality of first serrations abut against the motor shaft, the outer ring body is arranged between the first end cover and the connecting part, the outer ring body is provided with a plurality of second serrations, and the plurality of second serrations abut against the connecting part, the connecting part is fixedly connected to the main body, and the side lip is fixedly connected between the outer ring body and the connecting part.

[0022] As a preferred technical solution for the above-mentioned electric vehicle hub motor, the motor shaft is subjected to high-frequency quenching treatment.

[0023] The beneficial effects of the present invention are:

[0024] The present invention provides an electric vehicle hub motor, which includes a wheel hub, a first end cover, a second end cover, a motor shaft, a stator assembly and a drive assembly. The first end cover, the second end cover and the wheel hub are surrounded and form an accommodating cavity, in which cooling oil is stored. The motor shaft passes through the first end cover and the second end cover. The stator assembly includes a stator and a support frame. The stator assembly is located in the accommodating cavity and the support frame is fixedly sleeved on the motor shaft. An oil pump is provided on the support frame, connecting an oil channel and an oil inlet pipe. The oil inlet pipe is connected to the oil pump. An oil inlet hole and an oil outlet hole are provided on the oil pump. The oil inlet hole is connected to the oil inlet pipe. The stator comprises a stator core, an annular oil channel is formed between the support frame and the inner wall of the stator core, the connecting oil channel is connected to the annular oil channel, a plurality of oil inlets connected to the annular oil channel are provided on the inner wall of the stator core, the stator core comprises a plurality of stator teeth arranged at intervals, the plurality of oil inlets correspond one to one with the plurality of stator teeth, a cooling oil channel connected to the oil inlet is provided inside the stator teeth, a plurality of first oil outlets connected to the cooling oil channel are provided on the side walls of the stator teeth, and the drive assembly is fixedly connected to the first end cover and can drive the oil pump to rotate. With such an arrangement, when the wheel hub motor is working, the motor rotor assembly consisting of the wheel hub, the first end cover and the second end cover starts to rotate, thereby driving the drive assembly fixedly connected to the first end cover to rotate, thereby driving the oil pump to rotate, so that the oil inlet pipe pumps cooling oil from the bottom of the accommodating cavity, the cooling oil enters the oil inlet pipe, and enters the oil pump through the oil inlet hole, and then pumps out the cooling oil through the oil outlet hole, so that it enters the connecting oil channel and finally enters the annular oil channel connected to the connecting oil channel. The cooling oil flows in the annular oil channel and enters the oil pump through a plurality of oil inlets. Corresponding to the cooling channels in the stator teeth, after flowing through the cooling channels, the cooling oil eventually flows out from the side walls of the stator teeth and flows back to the bottom of the accommodating cavity under the action of gravity, thereby completing a complete cooling cycle of the electric vehicle hub motor. It does not require an additional motor to drive the oil pump, and can achieve active oil cooling through the motor rotor assembly structure, and cooperate with the entire cooling cycle loop to enable the stator to dissipate heat evenly and avoid excessive local temperature. At the same time, the electric vehicle hub motor can be well cooled when operating under any working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG1 is a cross-sectional view of an electric vehicle hub motor provided by the present invention;

[0026] FIG2 is a structural schematic diagram of a support frame provided by the present invention;

[0027] FIG3 is a second structural diagram of a support frame provided by the present invention;

[0028] FIG4 is a structural schematic diagram 1 of the support frame and the stator core provided by the present invention;

[0029] FIG5 is a second structural diagram of the support frame and the stator core provided by the present invention;

[0030] FIG6 is a third structural diagram of the support frame and the stator core provided by the present invention;

[0031] FIG7 is a cross-sectional view taken along line AA in FIG6 ;

[0032] FIG8 is a schematic structural diagram of a stator provided by the present invention;

[0033] FIG9 is a partial enlarged view of portion B in FIG8 ;

[0034] FIG10 is a schematic structural diagram of a stator core provided by the present invention;

[0035] FIG11 is a partial enlarged view of portion C in FIG10 ;

[0036] FIG12 is a schematic diagram of a partial structure of a hub motor for an electric vehicle provided by the present invention;

[0037] FIG13 is a second schematic diagram of the partial structure of the electric vehicle hub motor provided by the present invention.

[0038] Among them: 1. Hub; 2. First end cover; 3. Second end cover; 4. Accommodation chamber; 5. Motor shaft; 6. Stator assembly; 61. Stator; 611. Stator core; 612. Winding coil; 62. Support frame; 7. Oil pump; 71. Pump body; 72. Pump blade; 8. Connecting oil channel; 9. Oil inlet pipe; 10. Oil inlet hole; 11. Oil outlet hole; 12. Annular oil channel; 13. Oil inlet; 14. Cooling oil channel; 15. First oil outlet; 16. Cover plate; 17. Second oil outlet; 18. Third oil outlet; 19. Driving gear; 20. Driven gear; 21. Rotating shaft; 22. Pump chamber; 23. Groove; 24. First bearing; 25. First oil seal; 251. Inner ring; 2511. Main body; 2512. Connecting part; 252. Outer ring; 253. Side lip; 26. Magnet; 27. Second bearing; 28. Third bearing; 29. ​​Pressure plate; 30. Dust cover. DETAILED DESCRIPTION

[0039] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, but are not to be construed as limiting the present invention.

[0040] In the description of the present invention, it should be noted that the terms "center," "up," "down," "left," "right," "vertical," "horizontal," "inside," and "outside" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0041] Unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," and "fixed" should be interpreted broadly. For example, they may refer to fixed or removable connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0042] Unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first feature being in direct contact with the second feature, or may include the first feature being in contact with the second feature through another feature between them instead of being in direct contact. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0043] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0044] As shown in Figures 1 to 7, this embodiment provides an electric vehicle hub motor, which includes a wheel hub 1, a first end cover 2, a second end cover 3, a motor shaft 5, a stator assembly 6 and a drive assembly. The first end cover 2, the second end cover 3 and the wheel hub 1 are surrounded and form an accommodating cavity 4, in which cooling oil is stored. The motor shaft 5 passes through the first end cover 2 and the second end cover 3. The stator assembly 6 includes a stator 61 and a support frame 62. The stator assembly 6 is located in the accommodating cavity 4 and the support frame 62 is fixedly sleeved on the motor shaft 5. An oil pump 7 is provided on the support frame 62, connecting the oil channel 8 and the oil inlet pipe 9. The oil inlet pipe 9 is connected to the oil pump 7. The oil pump 7 is provided with an oil inlet hole 10 and an oil outlet hole 11. The oil inlet hole 10 is connected to the inlet The oil pipe 9 and the oil pump 7 are connected through the oil outlet 11, which connects the oil pump 7 to the connecting oil passage 8. The stator 61 includes a stator core 611. An annular oil passage 12 is formed between the support frame 62 and the inner wall of the stator core 611. The connecting oil passage 8 connects to the annular oil passage 12. The inner wall of the stator core 611 is provided with a plurality of oil inlets 13 connected to the annular oil passage 12. The stator core 611 includes a plurality of spaced stator teeth. The plurality of oil inlets 13 correspond one-to-one with the plurality of stator teeth. The interior of the stator teeth is provided with cooling oil passages 14 connected to the oil inlets 13. The side walls of the stator teeth are provided with a plurality of first oil outlets 15 connected to the cooling oil passages 14. The drive assembly is fixedly connected to the first end cover 2 and is capable of driving the oil pump 7 to rotate. In other embodiments, the drive assembly may also be fixedly connected to the second end cover 3. With such an arrangement, when the electric vehicle hub motor is working, the motor rotor assembly consisting of the hub 1, the first end cover 2 and the second end cover 3 starts to rotate, thereby driving the drive assembly fixedly connected to the first end cover 2 to rotate, thereby driving the oil pump 7 to rotate, so that the oil inlet pipe 9 pumps cooling oil into the bottom of the accommodating chamber 4, the cooling oil enters the oil inlet pipe 9, and enters the oil pump 7 through the oil inlet hole 10, and then pumps out the cooling oil through the oil outlet hole 11, so that it enters the connecting oil channel 8, and finally enters the annular oil channel 12 connected to the connecting oil channel 8. The cooling oil flows in the annular oil channel 12 and enters the cooling flow channel in the corresponding stator tooth through several oil inlets 13. After flowing through the cooling flow channel, the cooling oil finally flows out from the side wall of the stator tooth and flows back to the bottom end of the accommodating chamber 4 under the action of gravity, thereby completing a complete cooling cycle of the electric vehicle hub motor. It does not require an additional motor to drive the oil pump 7. Active oil cooling can be achieved through the motor rotor assembly structure. In conjunction with the entire cooling circuit, the stator 61 can dissipate heat evenly, preventing localized overheating. At the same time, the electric vehicle hub motor can be well cooled under all operating conditions. To more fully and thoroughly cool the stator 61, specifically, this embodiment exemplifies the following solution: a first oil outlet 15 is provided on two opposing side walls of each stator tooth.

[0045] It should be noted that the electric vehicle hub motor is usually configured as an outer rotor, which is sleeved on the outer periphery of the stator 61. In this embodiment, the outer rotor includes a magnet 26, which is fixedly connected to the wheel hub 1.

[0046] Optionally, as shown in Figures 8 and 9 , to further enhance the cooling effect on the stator 61, the stator 61 further includes a plurality of winding coils 612. These winding coils 612 are arranged in a one-to-one correspondence with the plurality of stator teeth, and the winding coils 612 are wound around the stator teeth. A cover plate 16 made of insulating material is provided between the winding coils 612 and the end surfaces of the stator teeth. A second oil outlet 17 is provided on the end surface of the stator tooth, which communicates with the cooling oil channel 14. The cover plate 16 is also provided with a plurality of third oil outlets 18 that communicate with the second oil outlet 17. With this arrangement, when cooling oil flows through the cooling flow channel within the stator tooth and out of the second oil outlet 17, it can continue to flow out through the plurality of third oil outlets 18 that communicate with the second oil outlet 17, and fully contact the winding coils 612 wound around the stator teeth, thereby removing heat generated by the winding coils 612 during operation. In this embodiment, two third oil outlets 18 are provided on the cover plate 16. Of course, in other embodiments, the number of the third oil outlets 18 can be set according to actual needs, and no further limitation is made here.

[0047] In this embodiment, the oil inlet 13, the first oil outlet 15, and the second oil outlet 17 are all rectangular in shape. Of course, in other embodiments, the oil inlet 13, the first oil outlet 15, and the second oil outlet 17 may also be racetrack-shaped or multi-circular in shape. The specific shapes can be set according to actual needs and are not further limited here.

[0048] In this embodiment, the support frame 62 includes a first section and a second section. The first section is fixedly connected to the inner wall of the stator core 611. The first section is fixedly connected to the second section. The second section is spaced apart from the inner wall of the stator core 611 to form an annular oil channel 12. The electric vehicle hub motor also includes a pressure plate 29, which is fixedly connected to the end face of the support frame 62 and the stator core 611.

[0049] Optionally, the drive assembly includes a driving gear 19, a driven gear 20 and a rotating shaft 21. The rotating shaft 21 is used to drive the oil pump 7 to rotate. The driving gear 19 is fixedly connected to the first end cover 2 and meshes with the driven gear 20. The driven gear 20 is fixedly sleeved on the rotating shaft 21. With this arrangement, when the electric vehicle hub motor is working, the motor rotor assembly structure rotates, thereby driving the driving gear 19 fixedly connected to the first end cover 2 to rotate. The driving gear 19 drives the driven gear 20 meshing therewith to rotate. The driven gear 20 drives the rotating shaft 21 fixedly connected thereto to rotate, and finally drives the oil pump 7 to rotate through the rotating shaft 21, thereby pumping the cooling oil into the bottom of the accommodating chamber 4. Furthermore, the electric vehicle hub motor also includes a bearing end cap and a second bearing 27. The bearing end cap is fixedly connected to the support frame 62. The outer ring of the second bearing 27 is fixedly connected to the bearing end cap, and the inner ring of the second bearing 27 is fixedly mounted on the rotating shaft 21. This arrangement enables the second bearing 27 to support the rotating shaft 21, reduce the friction coefficient of the rotating shaft 21 during rotation, and ensure its rotation accuracy. Furthermore, to prevent axial movement of the rotating shaft 21 during rotation, a retaining ring is fixedly mounted on the rotating shaft 21, and the retaining ring abuts the end face of the driven gear 20.

[0050] As an alternative, the drive assembly may further include a first pulley, a second pulley, a synchronous belt and a transmission shaft, the transmission shaft being used to drive the oil pump 7 to rotate, the first pulley being fixedly connected to the first end cover 2, the second pulley being fixedly sleeved on the transmission shaft, and the synchronous belt being simultaneously sleeved on the first pulley and the second pulley. With such an arrangement, when the electric vehicle hub motor is working, the first pulley rotates driven by the first end cover 2, and the first pulley serves as a driving wheel and drives the second pulley to rotate through the synchronous belt, and the second pulley drives the transmission shaft fixedly connected thereto to rotate, and finally drives the oil pump 7 through the transmission shaft. Of course, in other embodiments, the drive assembly may also be configured as a chain drive or a worm gear drive, and its specific transmission type may be configured according to actual needs and is not further limited here.

[0051] Alternatively, referring to FIG3 , the oil pump 7 includes a pump body 71 and pump blades 72. A pump cavity 22 is provided in the pump body 71. The pump blades 72 are disposed in the pump cavity 22 and are fixedly connected to the rotating shaft 21. The oil outlet 11 and the oil inlet 10 are both provided on the pump body 71. With this arrangement, the drive assembly drives the rotating shaft 21 to rotate, and the rotating shaft 21 in turn drives the pump blades 72 fixedly connected thereto to rotate in the pump cavity 22. Energy is then applied directly to the cooling oil in the form of static pressure on the side of the pump blades 72 in contact with the cooling oil in the pump cavity 22. The cooling oil is discharged by means of the squeezing action of the rotating pump blades 72. At the same time, space is left on the other side to form a low pressure, so that the cooling oil is continuously pumped into the pump cavity 22.

[0052] As an alternative, the oil pump 7 may also include a first pump body 71, a first gear and a second gear. The first pump body 71 is provided with a first pump cavity 22 and a second pump cavity 22. The first gear is provided in the first pump cavity 22, and the second gear is provided in the second pump cavity 22. The first gear is fixedly connected to the rotating shaft 21, and the first gear and the second gear are meshed. Furthermore, the end face of each tooth portion of the first gear and the second gear is provided with a chamfer. Of course, in other embodiments, the oil pump 7 may also be a vane pump, the specific type of which can be set according to actual needs and is not further restricted here.

[0053] Optionally, to facilitate assembly, the end faces of each tooth portion of the driving gear 19 and the driven gear 20 are chamfered. This arrangement facilitates the gear-to-gear assembly of the driving gear 19 and the driven gear 20, thereby improving the convenience of the overall installation process and increasing work efficiency.

[0054] Optionally, as shown in Figures 10 and 11 , each stator tooth is provided with a plurality of grooves 23 at the top. This configuration optimizes the magnetic field distribution around the stator teeth, reduces back-electromotive force harmonics and the harmonic content caused by the stator teeth, thereby reducing cogging torque and torque ripple, further improving the riding comfort of the electric vehicle at low speeds. In this embodiment, two grooves 23 are provided at the top of the stator teeth. Of course, in other embodiments, the number of grooves 23 can be set according to actual needs and is not further limited here.

[0055] Optionally, as shown in FIG12 , the electric vehicle hub motor further includes a first bearing 24, the outer ring of which is fixedly connected to the first end cap 2, and the inner ring of which is fixedly sleeved on the motor shaft 5. Specifically, the first end cap 2 is provided with a first center hole, the motor shaft 5 passes through the first center hole, and the outer ring of the first bearing 24 is fixedly connected to the hole wall of the first center hole. Of course, in other embodiments, the first bearing 24 may not be disposed within the first center hole of the first end cap 2, and the outer ring of the first bearing 24 may also be fixedly connected to the end face of the first end cap 2. The specific configuration can be based on actual needs and is not further limited here.

[0056] Optionally, the electric vehicle hub motor further includes a first oil seal 25, which includes an inner ring 251, an outer ring 252, and a side lip 253. The inner ring 251 is sleeved on the motor shaft 5, the outer ring 252 is interference fit with the first end cover 2, and is located between the first end cover 2 and the inner ring 251, and the side lip 253 is fixedly connected between the inner ring 251 and the outer ring 252. Specifically, the outer ring 252 is disposed between the inner ring 251 and the wall of the first center hole.

[0057] Furthermore, the inner ring body 251 includes a main body 2511 and a connecting portion 2512. The main body 2511 is sleeved on the motor shaft 5 and is provided with a plurality of first serrations that abut the motor shaft 5. The outer ring body 252 is disposed between the first end cap 2 and the connecting portion 2512 and is provided with a plurality of second serrations that abut the connecting portion 2512. The connecting portion 2512 is fixedly connected to the main body 2511, and the side lip 253 is fixedly connected between the outer ring body 252 and the connecting portion 2512. This arrangement adopts a combined oil seal structure, and the addition of the side lip 253 structure, i.e., a side sealing surface, further enhances the sealing effect and achieves a static seal. The side lip 253 can also exert a certain force on the main body 2511, causing it to adhere more closely to the motor shaft 5. Specifically, the outer ring body 252 is U-shaped, the connecting portion 2512 is L-shaped, and the outer ring body 252 is disposed between the connecting portion 2512 and the hole wall of the first central hole.

[0058] Optionally, the motor shaft 5 is subjected to high-frequency quenching treatment. This setting can further improve the hardness of the motor shaft 5, thereby reducing the excessive wear of the first oil seal 25 and the motor shaft 5 mating surface caused by insufficient hardness of the motor shaft 5, which leads to poor sealing performance of the electric vehicle hub motor and the risk of water entering the electric vehicle hub motor. Furthermore, the mating surfaces of the motor shaft 5, the first oil seal 25 and the first bearing 24 are subjected to high-frequency quenching treatment. The inner ring body 251 of the first oil seal 25 and the mating surface of the first bearing 24 and the motor shaft 5 can be made to have a hardness of 45HRC or more, which can greatly improve the hardness at the mating surface position, and can further make up for the deficiency that the hardness of the motor shaft 5 cannot meet the use requirements of the first oil seal 25.

[0059] As an alternative, as shown in FIG13 , the electric vehicle hub motor may further include a dust cover 30, which is located outside the first center hole and sleeved on the motor shaft 5. The dust cover 30 is Z-shaped, and one end of the Z-shaped dust cover 30 is interference-fitted with the motor shaft 5. The first end cap 2 is provided with a receiving groove, and the other end of the Z-shaped dust cover 30 is located in the receiving groove. The outer ring body 252 is sleeved on the motor shaft 5. The outer ring body 252 is arranged in the first center hole and is located between the hole wall of the first center hole and the motor shaft 5. The outer ring body 252 is interference-fitted with the first end cap 2. The L-shaped connecting portion 2512 is always configured to apply a force to the outer ring body 252 so that the inner wall of the outer ring body 252 is in close contact with the motor shaft 5. In this embodiment, the dust cover and the mating surface of the outer ring body 252 and the motor shaft 5 are subjected to high-frequency quenching.

[0060] In this embodiment, the first oil seal 25 is disposed on the outside of the first bearing 24, and the first oil seal 25 is closer to one end of the motor shaft 5 than the first bearing 24. Of course, in other embodiments, the first oil seal 25 may also be disposed on the inside of the first bearing 24, and the first bearing 24 is closer to one end of the motor shaft 5 than the first oil seal 25. The specific installation positions of the two can be set according to actual needs and are not further limited here.

[0061] Optionally, the electric vehicle hub motor further includes a third bearing 28, the outer ring of which is fixedly connected to the second end cap 3, and the inner ring of which is fixedly sleeved on the motor shaft 5. Specifically, the second end cap 3 is provided with a second center hole, the motor shaft 5 passes through the second center hole, and the outer ring of the third bearing 28 is fixedly connected to the hole wall of the second center hole. Of course, in other embodiments, the third bearing 28 may not be disposed within the second center hole of the second end cap 3, and the outer ring of the third bearing 28 may also be fixedly connected to the end face of the second end cap 3. The specific configuration can be based on actual needs and is not further limited here.

[0062] Optionally, the electric vehicle hub motor also includes a second oil seal. The specific structure of the second oil seal is identical to that of the first oil seal 25 and will not be further described here. In this embodiment, the second oil seal is disposed on the outside of the third bearing 28 and is closer to the other end of the motor shaft 5 than the third bearing 28. Of course, in other embodiments, the second oil seal may also be disposed on the inside of the third bearing 28, with the third bearing 28 closer to the other end of the motor shaft 5 than the second oil seal. The specific installation positions of the two oil seals can be set according to actual needs and are not further limited here.

[0063] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. An electric vehicle hub motor, characterized in that: include: Wheel hub (1); A first end cover (2) and a second end cover (3), wherein the first end cover (2), the second end cover (3) and the wheel hub (1) surround and form a receiving cavity (4), wherein cooling oil is stored in the receiving cavity (4); A motor shaft (5), wherein the motor shaft (5) passes through the first end cover (2) and the second end cover (3); A stator assembly (6), the stator assembly (6) comprising a stator (61) and a support frame (62), the stator assembly (6) being located in the accommodating cavity (4) and the support frame (62) being fixedly sleeved on the motor shaft (5), an oil pump (7) being provided on the support frame (62), connecting an oil passage (8) and an oil inlet pipe (9), the oil inlet pipe (9) being connected to the oil pump (7), an oil inlet hole (10) and an oil outlet hole (11) being provided on the oil pump (7), the oil inlet hole (10) being connected to the oil inlet pipe (9) and the oil pump (7), the oil outlet hole (11) being connected to the oil pump (7) and the connecting oil passage (8), the stator (61) comprising a stator stator core (611), an annular oil passage (12) is formed between the support frame (62) and the inner wall of the stator core (611), the connecting oil passage (8) is connected to the annular oil passage (12), a plurality of oil inlets (13) connected to the annular oil passage (12) are provided on the inner wall of the stator core (611), the stator core (611) comprises a plurality of stator teeth arranged at intervals, the plurality of oil inlets (13) correspond to the plurality of stator teeth one by one, a cooling oil passage (14) connected to the oil inlet (13) is provided inside the stator teeth, and a plurality of first oil outlets (15) connected to the cooling oil passage (14) are provided on the side walls of the stator teeth; A drive assembly, wherein the drive assembly is fixedly connected to the first end cover (2) and is capable of driving the oil pump (7) to rotate.

2. The electric vehicle hub motor according to claim 1, characterized in that: The stator (61) further comprises a plurality of winding coils (612), the plurality of winding coils (612) being arranged in one-to-one correspondence with the plurality of stator teeth, and the winding coils (612) being wound around the stator teeth, a cover plate (16) being arranged between the winding coils (612) and the end faces of the stator teeth, the cover plate (16) being made of insulating material, a second oil outlet (17) being arranged on the end faces of the stator teeth, the second oil outlet (17) being connected to the cooling oil channel (14), and a plurality of third oil outlets (18) being arranged on the cover plate (16) and being connected to the second oil outlet (17).

3. The electric vehicle hub motor according to claim 1, characterized in that: The driving assembly comprises a driving gear (19), a driven gear (20) and a rotating shaft (21). The rotating shaft (21) is used to drive the oil pump (7) to rotate. The driving gear (19) is fixedly connected to the first end cover (2) and meshes with the driven gear (20). The driven gear (20) is fixedly sleeved on the rotating shaft (21).

4. The electric vehicle hub motor according to claim 3, characterized in that: The oil pump (7) comprises a pump body (71) and a pump blade (72). A pump cavity (22) is provided in the pump body (71). The pump blade (72) is arranged in the pump cavity (22) and is fixedly connected to the rotating shaft (21). The oil outlet hole (11) and the oil inlet hole (10) are both arranged on the pump body (71).

5. The electric vehicle hub motor according to claim 3, characterized in that: The end faces of each tooth portion of the driving gear (19) and the driven gear (20) are chamfered.

6. The electric vehicle hub motor according to any one of claims 1 to 5, characterized in that: A plurality of grooves (23) are provided on the top of each stator tooth.

7. The electric vehicle hub motor according to any one of claims 1 to 5, characterized in that: The electric vehicle hub motor further comprises a first bearing (24), the outer ring of the first bearing (24) being fixedly connected to the first end cover (2), and the inner ring of the first bearing (24) being fixedly sleeved on the motor shaft (5).

8. The electric vehicle hub motor according to claim 7, characterized in that: The electric vehicle hub motor also includes a first oil seal (25), which includes an inner ring body (251), an outer ring body (252) and a side lip (253). The inner ring body (251) is sleeved on the motor shaft (5), the outer ring body (252) is interference fit with the first end cover (2) and is located between the first end cover (2) and the inner ring body (251), and the side lip (253) is fixedly connected between the inner ring body (251) and the outer ring body (252).

9. The electric vehicle hub motor according to claim 8, characterized in that: The inner ring body (251) includes a main body (2511) and a connecting portion (2512); the main body (2511) is sleeved on the motor shaft (5); the main body (2511) is provided with a plurality of first saw teeth, and the plurality of first saw teeth abut against the motor shaft (5); the outer ring body (252) is arranged between the first end cover (2) and the connecting portion (2512); the outer ring body (252) is provided with a plurality of second saw teeth, and the plurality of second saw teeth abut against the connecting portion (2512); the connecting portion (2512) is fixedly connected to the main body (2511), and the side lip (253) is fixedly connected between the outer ring body (252) and the connecting portion (2512).

10. The electric vehicle hub motor according to claim 9, characterized in that: The motor shaft (5) is subjected to high frequency quenching treatment.

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