Hub motor of electric vehicle

Abstract

The utility model relates to the technical field of motors for electric vehicles, in particular to a hub motor for an electric vehicle, which is characterized in that a stator core is fixedly mounted on a motor shaft and comprises a left iron core and a right iron core which are integrally formed, the left iron core is alternately provided with a plurality of first stator teeth and a plurality of first stator grooves along the circumferential direction, and the right iron core is provided with a plurality of second stator teeth and a plurality of second stator grooves; the right iron core is alternately provided with a plurality of second stator teeth and a plurality of second stator grooves in the circumferential direction, notches of the first stator grooves and notches of the second stator grooves face the two axial sides of the motor shaft, the first coil winding is wound around the first stator teeth, the second coil winding is wound around the second stator teeth, the left rotor magnetic steel is installed in the left end cover, and the right rotor magnetic steel is installed in the right end cover. And the right rotor magnetic steel is arranged in the right end cover and corresponds to the right iron core. A rotor-stator-rotor structure is adopted, and a stator core adopts an axial double-groove type and is designed corresponding to double rotors and double magnetic steel groups, so that double-power axial output is realized, and the torque and the power density of the motor are remarkably improved.

Description

Technical Field

[0001] This utility model relates to the field of electric vehicle motor technology, and in particular to an electric vehicle hub motor. Background Technology

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

[0003] Hub motors are commonly used as the main motor structure for electric two-wheelers due to their high reliability and small size. Structurally, they typically employ a direct-drive method with an external rotor and stator, where power is directly output through the external rotor. Their main function is to provide continuous and stable power to the electric vehicle. They do not require any transmission system, and the driving force acts directly on the wheels. They are characterized by high driving efficiency, compact structure, and high reliability. However, existing direct-drive hub motors for electric vehicles have limited adaptability to loads, especially in high-load, high-torque situations. To maximize climbing performance, i.e., maximize torque, higher requirements are placed on the operating power of the hub motors for electric vehicles. Utility Model Content

[0004] The purpose of this invention is to provide an electric vehicle hub motor that can achieve dual power axial output, effectively improving the motor torque and power density.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This utility model provides a hub motor for an electric vehicle, comprising:

[0007] Wheel hub;

[0008] The left end cover and the right end cover, together with the wheel hub, surround and form a receiving cavity;

[0009] A motor shaft, which passes through the left end cover and the right end cover;

[0010] A stator assembly is disposed within the receiving cavity and includes a stator core, a plurality of first coil windings, and a plurality of second coil windings. The stator core is fixedly mounted on the motor shaft and includes an integrally formed left core and a right core. The left core is alternately provided with a plurality of first stator teeth and a plurality of first stator slots along the circumferential direction, and the right core is alternately provided with a plurality of second stator teeth and a plurality of second stator slots along the circumferential direction. The slot openings of the first stator slots and the slot openings of the second stator slots face the axial sides of the motor shaft. A plurality of first coil windings are arranged in a one-to-one correspondence with a plurality of first stator teeth, and the first coil windings are wound around the first stator teeth. A plurality of second coil windings are arranged in a one-to-one correspondence with a plurality of second stator teeth, and the second coil windings are wound around the second stator teeth.

[0011] A left rotor magnet is installed inside the left end cover and corresponds to the left iron core;

[0012] The right rotor magnet is installed inside the right end cover and corresponds to the right iron core.

[0013] As a preferred technical solution for the above-mentioned electric vehicle hub motor, the stator assembly further includes a support frame, which is fixedly installed on the motor shaft, and the stator core is fixedly sleeved on the outer peripheral wall of the support frame.

[0014] As a preferred technical solution for the above-mentioned electric vehicle hub motor, the left rotor magnet includes a plurality of first magnet bodies, which are evenly arranged along the circumferential direction and are all bonded to the left end cover. The right rotor magnet includes a plurality of second magnet bodies, which are evenly arranged along the circumferential direction and are all bonded to the right end cover.

[0015] As a preferred technical solution for the above-mentioned electric vehicle hub motor, both the first magnet body and the second magnet body are fan-shaped.

[0016] As a preferred technical solution for the above-mentioned electric vehicle hub motor, the first magnet body has a first chamfer at both ends along its own length direction, and the second magnet body has a second chamfer at both ends along its own length direction.

[0017] As a preferred technical solution for the above-mentioned electric vehicle hub motor, the left rotor magnet and the left iron core are arranged at intervals to form a first axial air gap, and the right rotor magnet and the right iron core are arranged at intervals to form a second axial air gap.

[0018] As a preferred technical solution for the above-mentioned electric vehicle hub motor, the two opposite and spaced sidewalls of the first stator tooth are parallel to each other, and the two opposite and spaced sidewalls of the second stator tooth are parallel to each other.

[0019] As a preferred technical solution for the above-mentioned electric vehicle hub motor, the openings of the first stator slot and the second stator slot are both V-shaped.

[0020] As a preferred technical solution for the above-mentioned electric vehicle hub motor, the left iron core has a first magnetic yoke portion, and the right iron core has a second magnetic yoke portion, wherein the first magnetic yoke portion and the second magnetic yoke portion coincide.

[0021] As a preferred technical solution for the above-mentioned electric vehicle hub motor, the electric vehicle hub motor further includes a first bearing and a second bearing. The outer ring of the first bearing is fixedly connected to the left end cover, and the inner ring of the first bearing is fixedly sleeved on the motor shaft. The outer ring of the second bearing is fixedly connected to the right end cover, and the inner ring of the second bearing is fixedly sleeved on the motor shaft.

[0022] The beneficial effects of this utility model are as follows:

[0023] This utility model provides a hub motor for an electric vehicle, comprising: a hub, a left end cover, a right end cover, a motor shaft, a stator assembly, a left rotor magnet, and a right rotor magnet. The left and right end covers surround and form a receiving cavity with the hub. The motor shaft passes through the left and right end covers. The stator assembly is disposed within the receiving cavity and includes a stator core, a plurality of first coil windings, and a plurality of second coil windings. The stator core is fixedly mounted on the motor shaft and includes an integrally formed left core and a right core. The left core has a plurality of first stators alternately arranged along the circumferential direction. The motor has several first stator slots and several second stator teeth and slots arranged alternately along the circumference of the right stator core. The openings of the first and second stator slots face the axial sides of the motor shaft. Several first coil windings are arranged one-to-one with several first stator teeth, and the first coil windings are wound around the first stator teeth. Several second coil windings are arranged one-to-one with several second stator teeth, and the second coil windings are wound around the second stator teeth. The left rotor magnet is installed inside the left end cover and corresponds to the left stator core, and the right rotor magnet is installed inside the right end cover and corresponds to the right stator core. This arrangement adopts a "rotor-stator-rotor" structure. The stator core adopts an axial double-slot type and a dual-rotor, dual-magnet design corresponding to the left and right rotor magnets to achieve dual-power axial output, significantly improving the motor's torque and power density. Attached Figure Description

[0024] Figure 1 A cross-sectional view of the electric vehicle hub motor provided by this utility model;

[0025] Figure 2 for Figure 1 A magnified view of part A in the middle;

[0026] Figure 3 for Figure 1 A magnified view of part B in the middle section;

[0027] Figure 4 Exploded view of the electric vehicle hub motor provided by this utility model;

[0028] Figure 5 A partial structural diagram of the electric vehicle hub motor provided by this utility model. Figure 1 ;

[0029] Figure 6 A partial structural diagram of the electric vehicle hub motor provided by this utility model. Figure 2 ;

[0030] Figure 7 A partial structural diagram of the electric vehicle hub motor provided by this utility model. Figure 3 ;

[0031] Figure 8 for Figure 7 A magnified view of part C in the middle;

[0032] Figure 9 This is a schematic diagram of the stator core provided by this utility model.

[0033] in:

[0034] 1. Wheel hub; 2. Left end cover; 3. Right end cover; 4. Motor shaft;

[0035] 5. Stator core; 6. First coil winding; 7. Second coil winding; 8. First stator tooth; 9. First stator slot; 10. Second stator tooth; 11. Second stator slot; 12. Left rotor magnet; 13. Right rotor magnet; 14. Support frame; 15. Second chamfer; 16. First axial air gap; 17. Second axial air gap; 18. First bearing; 19. Second bearing; 20. First oil seal; 21. Second oil seal. Detailed Implementation

[0036] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0037] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. 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.

[0038] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and connections within two components or interactions between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0039] Unless otherwise expressly specified and limited, "above" or "below" a second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of a second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" of a second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0040] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0041] like Figures 1 to 9As shown, this embodiment provides an electric vehicle hub motor, which includes: a hub 1, a left end cover 2, a right end cover 3, a motor shaft 4, a stator assembly, a left rotor magnet 12, and a right rotor magnet 13. The left end cover 2, the right end cover 3, and the hub 1 surround and form a receiving cavity. The motor shaft 4 passes through the left end cover 2 and the right end cover 3. The stator assembly is disposed in the receiving cavity, and the stator assembly includes a stator core 5, a plurality of first coil windings 6, and a plurality of second coil windings 7. The stator core 5 is fixedly installed on the motor shaft 4, and the stator core 5 includes an integrally formed left core and a right core. The left core is alternately provided with a plurality of first stator teeth 8 along the circumferential direction. Along with several first stator slots 9, the right iron core is alternately provided with several second stator teeth 10 and several second stator slots 11 along the circumferential direction. The slot openings of the first stator slots 9 and the slot openings of the second stator slots 11 face the axial sides of the motor shaft 4. Several first coil windings 6 are arranged one-to-one with several first stator teeth 8, and the first coil windings 6 are wound around the first stator teeth 8. Several second coil windings 7 are arranged one-to-one with several second stator teeth 10, and the second coil windings 7 are wound around the second stator teeth 10. The left rotor magnet 12 is installed in the left end cover 2 and corresponds to the left iron core. The right rotor magnet 13 is installed in the right end cover 3 and corresponds to the right iron core. This arrangement adopts a "rotor-stator-rotor" structure. The stator iron core 5 adopts an axial double-slot type and corresponds to the double rotor double magnet group design of the left rotor magnet 12 and the right rotor magnet 13 to achieve dual power axial output, significantly improving the torque and power density of the motor.

[0042] It should be noted that the axial double-slot stator core 5 provides twice the space, accommodating more winding turns, greatly improving the fill factor of both stator slots, reducing copper losses, and increasing motor efficiency. It also increases the motor's magnetomotive force, which is beneficial for improving the motor's output power and torque. At the same time, the double-slot structure of the stator core 5 allows for more flexible arrangement of the corresponding coil windings, enabling the use of various winding forms and connection methods according to different motor performance requirements, further optimizing the motor's electromagnetic performance.

[0043] In this embodiment, the left and right iron cores are evenly distributed in the circumferential direction and maintain a corresponding parallel and symmetrical design. This symmetrical arrangement ensures the consistency of the output torque of the rotors on both sides of the motor, helps to achieve a uniform distribution of the magnetic field inside the motor, makes the electromagnetic force generated by the motor during operation more balanced, reduces vibration and noise caused by magnetic field asymmetry, and improves the stability and reliability of motor operation.

[0044] Optionally, in order to enhance the connection stability and reliability of the stator core 5, the stator assembly also includes a support frame 14, which is fixedly installed on the motor shaft 4, and the stator core 5 is fixedly sleeved on the outer peripheral wall of the support frame 14.

[0045] Optionally, the left rotor magnet 12 includes a plurality of first magnet bodies, which are evenly arranged along the circumference and are bonded to the inner wall of the left end cover 2 or to an annular groove. The right rotor magnet 13 includes a plurality of second magnet bodies, which are evenly arranged along the circumference and are bonded to the inner wall of the right end cover 3 or to an annular groove. Both the first and second magnet bodies are permanent magnets. This arrangement, with the plurality of first and second magnet bodies evenly distributed along the circumference to form an annular structure, allows for better adaptation to the circular structure of the motor rotor and enables a close arrangement of magnets within a limited space.

[0046] Furthermore, both the first and second magnet bodies are fan-shaped or trapezoidal. This arrangement allows the fan-shaped magnets to make fuller use of the rotor space, reducing the gaps between magnets and thus increasing the magnet filling rate and the motor's magnetic flux, which helps improve motor performance. Simultaneously, the regular shape of the fan-shaped magnets makes them easier to position and fix during installation, enabling reliable connection with the left end cover 2 and right end cover 3 of the rotor mounting base, achieving circumferential positioning. Moreover, the evenly distributed fan-shaped magnets provide relatively uniform stress distribution, better withstanding centrifugal forces and other external forces during motor operation, reducing the risk of magnet loosening or detachment, and improving the stability of motor operation.

[0047] Optionally, such as Figure 7 and 8 As shown, the first magnet body has a first chamfer at both ends along its length, and the second magnet body has a second chamfer at both ends along its length. This arrangement, by chamfering the ends corresponding to the magnetic poles, reduces the contact area between adjacent magnets, significantly improving inter-pole magnetic leakage within the motor and thus increasing the effective utilization rate of the magnets. The fan-shaped first and second magnet bodies are radially magnetized, with the magnetic field concentrated at the outer arc of the fan-shaped region. The magnetic field lines can point from the N pole of the outer arc to the S pole inside, thereby forming a uniform radial magnetic field within the fan-shaped region.

[0048] Optionally, to achieve a higher power density and efficiency axial flux motor and significantly improve the motor's output torque, the left rotor magnet 12 is spaced apart from the left iron core to form a first axial air gap 16, and the right rotor magnet 13 is spaced apart from the right iron core to form a second axial air gap 17. With this arrangement, when the fan-shaped first and second magnet bodies are evenly distributed on the motor rotor, a more ideal magnetic field distribution, closer to a standard sine wave, can be formed in the first axial air gap 16 and the second axial air gap 17. In this dual-power axial permanent magnet motor, this magnetic field distribution effectively reduces spatial harmonic content, reduces potential fluctuations, and optimizes the motor's core losses, induced electromotive force, and other electromagnetic parameters, thereby improving motor efficiency and reducing vibration and noise.

[0049] Optionally, the two opposite and spaced sidewalls of the first stator tooth 8 are parallel to each other, and the two opposite and spaced sidewalls of the second stator tooth 10 are parallel to each other. This arrangement enables more efficient engagement of the first coil winding 6 and the second coil winding 7, and ensures that the magnetic fields on both axial sides are the same, thus guaranteeing consistency, stability, and equal torque on both axial sides during motor operation.

[0050] Optionally, in order to greatly reduce torque fluctuations and make the magnetic field generated by the first coil winding 6 and the second coil winding 7 more concentrated and evenly distributed in the first axial air gap 16 and the second axial air gap 17, thereby reducing magnetic field leakage and distortion, the slot openings of the first stator slot 9 and the second stator slot 11 are both V-shaped.

[0051] Optionally, the left core has a first magnetic yoke, and the right core has a second magnetic yoke, with the first and second magnetic yokes overlapping. This configuration allows the left and right cores on both sides of the stator core 5 to use the same yoke structure, i.e., a conjugate portion. This ensures the overall structural strength of the stator core 5 while maintaining compactness, achieving higher power density within a limited axial space. It also further integrates and "flattens" the axial motor structure, improving motor performance without increasing motor size or weight. Furthermore, it maintains magnetic field flow within its existing thickness and width, reducing motor iron losses. Additionally, the designed mounting position is on the inner circumference of the conjugate portion, allowing it to be installed and fitted with the support frame 14, thus enabling the component's positioning and installation.

[0052] Optionally, in order to better support the rotation of the motor shaft 4, reduce friction, and ensure its operating accuracy and efficiency, the electric vehicle hub motor also includes a first bearing 18 and a second bearing 19. The outer ring of the first bearing 18 is fixedly connected to the left end cover 2, and the inner ring of the first bearing 18 is fixedly sleeved on the motor shaft 4. The outer ring of the second bearing 19 is fixedly connected to the right end cover 3, and the inner ring of the second bearing 19 is fixedly sleeved on the motor shaft 4.

[0053] In this embodiment, the electric vehicle hub motor also includes a first oil seal 20 and a second oil seal 21. The first oil seal 20 is disposed between the left end cover 2 and the motor shaft 4, and the second oil seal 21 is disposed between the right end cover 3 and the motor shaft 4.

[0054] The working principle of the electric vehicle hub motor in this embodiment will be further explained below:

[0055] Both the first coil winding 6 and the second coil winding 7 adopt a flat wire vertical winding structure and are respectively embedded on the left iron core and the right iron core. After installation, a first axial air gap 16 and a second axial air gap 17 are formed on both sides. Specifically, the distance between the first axial air gap 16 and the second axial air gap 17 is controlled between 0.2mm and 0.5mm. In fact, a dual driving force is formed inside this motor. The left power is the left rotor magnet 12, the first coil winding 6, the left iron core, the first magnetic yoke (conjugate part), and the first axial air gap 16. The right power is the right rotor magnet 13, the second coil winding 7, the right iron core, the second magnetic yoke (conjugate part), and the second axial air gap 17. The left and right powers share the motor shaft 4 as the through shaft.

[0056] When the motor is running, the rotor assembly, including the left end cover 2 with the left rotor magnet 12, the right end cover 3 with the right rotor magnet 13, and the hub 1, interacts with both sides of the stator assembly along the axial direction. This increases the area and frequency of electromagnetic force application, driving the rotation of the motor rotor assembly and thus achieving double the torque output. This allows the motor to generate greater torque within the same volume and weight, achieving higher power density.

[0057] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A hub motor for an electric vehicle, characterized in that, include: Wheel hub (1); The left end cap (2) and the right end cap (3) are arranged together with the hub (1) to form a receiving cavity; Motor shaft (4), the motor shaft (4) passes through the left end cover (2) and the right end cover (3); A stator assembly is disposed within the receiving cavity, and the stator assembly includes a stator core (5), a plurality of first coil windings (6) and a plurality of second coil windings (7). The stator core (5) is fixedly mounted on the motor shaft (4), and the stator core (5) includes an integrally formed left core and a right core. The left core is alternately provided with a plurality of first stator teeth (8) and a plurality of first stator slots (9) along the circumferential direction, and the right core is alternately provided with a plurality of second stator teeth (10) and a plurality of second stator slots (9) along the circumferential direction. The second stator slot (11) has the slot openings of the first stator slot (9) and the slot openings of the second stator slot (11) facing the axial sides of the motor shaft (4). A plurality of first coil windings (6) are arranged in a one-to-one correspondence with a plurality of first stator teeth (8), and the first coil windings (6) are wound around the first stator teeth (8). A plurality of second coil windings (7) are arranged in a one-to-one correspondence with a plurality of second stator teeth (10), and the second coil windings (7) are wound around the second stator teeth (10). The left rotor magnet (12) is installed inside the left end cover (2) and corresponds to the left iron core; The right rotor magnet (13) is installed inside the right end cover (3) and corresponds to the right iron core.

2. The electric vehicle hub motor according to claim 1, characterized in that, The stator assembly also includes a support frame (14), which is fixedly mounted on the motor shaft (4), and the stator core (5) is fixedly sleeved on the outer peripheral wall of the support frame (14).

3. The electric vehicle hub motor according to claim 1, characterized in that, The left rotor magnet (12) includes a plurality of first magnet bodies, which are evenly arranged along the circumferential direction and are all bonded to the left end cover (2). The right rotor magnet (13) includes a plurality of second magnet bodies, which are evenly arranged along the circumferential direction and are all bonded to the right end cover (3).

4. The electric vehicle hub motor according to claim 3, characterized in that, Both the first magnet body and the second magnet body are fan-shaped.

5. The electric vehicle hub motor according to claim 3, characterized in that, The first magnet body has a first chamfer at both ends along its length direction, and the second magnet body has a second chamfer at both ends along its length direction (15).

6. The electric vehicle hub motor according to any one of claims 1-5, characterized in that, The left rotor magnet (12) is arranged at intervals with the left iron core to form a first axial air gap (16), and the right rotor magnet (13) is arranged at intervals with the right iron core to form a second axial air gap (17).

7. The electric vehicle hub motor according to any one of claims 1-5, characterized in that, The two opposite and spaced sidewalls of the first stator tooth (8) are parallel to each other, and the two opposite and spaced sidewalls of the second stator tooth (10) are parallel to each other.

8. The electric vehicle hub motor according to any one of claims 1-5, characterized in that, The opening of the first stator slot (9) and the opening of the second stator slot (11) are both V-shaped.

9. The electric vehicle hub motor according to any one of claims 1-5, characterized in that, The left iron core has a first magnetic yoke portion, and the right iron core has a second magnetic yoke portion, with the first magnetic yoke portion coinciding with the second magnetic yoke portion.

10. The electric vehicle hub motor according to any one of claims 1-5, characterized in that, The electric vehicle hub motor also includes a first bearing (18) and a second bearing (19). The outer ring of the first bearing (18) is fixedly connected to the left end cover (2), and the inner ring of the first bearing (18) is fixedly sleeved on the motor shaft (4). The outer ring of the second bearing (19) is fixedly connected to the right end cover (3), and the inner ring of the second bearing (19) is fixedly sleeved on the motor shaft (4).

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