Asynchronous motor and vehicle comprising asynchronous motor

Abstract

The utility model relates to an asynchronous motor and a vehicle comprising the same. The asynchronous motor comprises a stator assembly and a rotor assembly. The stator assembly comprises a stator iron core, a plurality of stator teeth extending inwards from the inner circumference of the stator iron core in the radial direction are arranged on the stator iron core at equal intervals in the circumferential direction of the stator iron core, and a stator groove is defined between every two adjacent stator teeth. The rotor assembly comprises a rotor iron core, and a plurality of rotor grooves extending in the radial direction are formed in the rotor iron core at equal intervals in the circumferential direction of the rotor iron core. The asynchronous motor is formed as a 6-pole asynchronous motor and is designed to have 54 stator slots and 64 rotor slots. The asynchronous motor provided by the utility model is low in torque pulsation, good in NVH performance, small in pulsating loss on the surface of the rotor, and high in motor efficiency, and can share the same stator assembly with the 6-pole permanent magnet synchronous motor, thereby improving the universality between parts of the synchronous motor and the asynchronous motor.

Description

Technical Field

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

[0002] As one of the core components of new energy vehicles, the electric motor plays a decisive role in their performance. Based on their structure and working principle, electric motors can be divided into synchronous motors and asynchronous motors. Synchronous motors use permanent magnets as rotors, generating torque through the interaction of magnetic fields. Asynchronous motors, on the other hand, generate a rotating magnetic field in their stator. By placing the squirrel-cage rotor within this rotating magnetic field, the rotor produces rotational torque under its influence.

[0003] The number of poles in a motor refers to the number of magnetic poles generated by the stator windings. It is a crucial parameter that significantly impacts the motor's performance and applications. For example, a lower pole number generally results in a higher rotational speed at the same electrical frequency. Currently, most motors used in new energy vehicles are permanent magnet synchronous motors, typically with eight poles. However, with the rapid development of new energy vehicles, the demands on motor speeds are increasing, and the commonly used eight-pole permanent magnet synchronous motors can no longer meet market requirements. Furthermore, the application of asynchronous motors in the new energy vehicle market is limited, and most are four-pole asynchronous motors used in industrial applications. The components used in synchronous and asynchronous motors for new energy vehicles also have low commonality.

[0004] To improve the application of electric motors in the new energy vehicle field, the application of asynchronous motors is an important research direction. To reduce the design and manufacturing costs of motors, it is necessary to improve the component interchangeability between synchronous and asynchronous motors. Furthermore, existing asynchronous motors suffer from high torque ripple, which reduces motor operating smoothness, increases noise, accelerates wear of mechanical components, and shortens motor lifespan. Therefore, there is a need to propose an improved asynchronous motor, particularly for the new energy vehicle field, that can overcome at least one of the aforementioned problems and / or other issues known in existing technologies. Utility Model Content

[0005] To achieve the above objectives, according to one aspect of the present invention, an asynchronous motor is provided, the asynchronous motor comprising: a stator assembly including a stator core, the stator core having a plurality of stator teeth arranged at equal intervals along its circumference, extending radially inward from its inner circumference, wherein a stator slot is defined between every two adjacent stator teeth; and a rotor assembly including a rotor core, the rotor core having a plurality of rotor slots arranged at equal intervals along its circumference, extending radially; wherein the asynchronous motor is configured as a 6-pole asynchronous motor, the 6-pole asynchronous motor being designed to have 54 stator slots and 64 rotor slots.

[0006] In one embodiment, the rotor slot is formed as an open slot that is radially recessed from the outer peripheral wall of the rotor core, and the open slot extends from the first axial end of the rotor core to the second axial end of the rotor core.

[0007] In one embodiment, the rotor slot has a cross-section taken along a plane perpendicular to the axial direction of the rotor core, and the cross-section of the rotor slot includes a tapering section, the width of which gradually decreases radially inward to the end of the rotor slot.

[0008] In one embodiment, the cross-section of the rotor slot further includes an open section and an intermediate section connecting the open section and the tapering section, wherein the slot width of the intermediate section gradually increases radially inward.

[0009] In one embodiment, the rotor slot has a pair of opposing stops at the portion corresponding to the middle section of the cross section.

[0010] As one implementation, each of the stops is formed with rounded corners.

[0011] In one embodiment, the slot width of the opening section is constant radially inward and defines a first slot width, while a second slot width is defined at the transition between the middle section and the tapered section of the rotor slot, wherein the ratio of the first slot width to the second slot width is 0.7 to 0.8.

[0012] In one implementation, the stator core of the 6-pole asynchronous motor is configured to be compatible with the permanent magnet rotor of the 6-pole permanent magnet synchronous motor.

[0013] As one embodiment, the stator assembly further includes a stator winding, wherein six layers of flat wire winding conductors are arranged in the stator slots.

[0014] According to another aspect of the present invention, a vehicle is provided, the vehicle including an asynchronous motor as described above.

[0015] This invention proposes an asynchronous motor particularly suitable for new energy vehicles. By using a specific stator and rotor pole slot combination (i.e., by configuring it as a 6-pole asynchronous motor with 54 stator slots and 64 rotor slots), stray losses are reduced, torque ripple is significantly reduced, and the smoothness of electric drive system operation and NVH performance are improved. Furthermore, by setting the rotor slots to be open slots, the motor torque is increased. At the same time, it can be switched with a 6-pole permanent magnet synchronous motor, thereby improving the versatility of components and saving material costs. Attached Figure Description

[0016] The features and advantages of this utility model will become clear from the following detailed description provided with reference to the accompanying drawings. It should be understood that the following drawings are merely schematic and not necessarily drawn to scale, and therefore should not be considered as limitations on this utility model, wherein:

[0017] Figure 1 A perspective view of an asynchronous motor according to an embodiment of the present invention is shown, in which the stator winding is not shown.

[0018] Figure 2 Show Figure 1 The diagram shows a three-dimensional view of the rotor assembly of an asynchronous motor.

[0019] Figure 3 Show Figure 1 The image shows the front view of the asynchronous motor.

[0020] Figure 4 Show Figure 1 The graph shown illustrates the torque variation with the rotor rotation angle of an asynchronous motor with 66 rotor slots in the rotor core.

[0021] Figure 5 Show Figure 1 The graph shown illustrates the torque variation with the rotor rotation angle of an asynchronous motor with 64 rotor slots in the rotor core.

[0022] Figure 6 Show Figure 1 The graphs shown depict the peak torque versus rotational speed when the rotor slots of the asynchronous motor's rotor core are open and closed slots, respectively.

[0023] Figure 7 Show Figure 3 The enlarged cross-sectional view of part A of the asynchronous motor shown. Detailed Implementation

[0024] Embodiments of the present invention are described below with reference to the accompanying drawings. In the following description, numerous specific details are set forth to enable those skilled in the art to more fully understand and implement the present invention. However, it will be apparent to those skilled in the art that implementations of the present invention may not include some of these specific details. Furthermore, it should be understood that the present invention is not limited to the specific embodiments described. Rather, the present invention can be conceived to be implemented with any combination of the features and elements described below, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments, and advantages are for illustrative purposes only and should not be construed as elements or limitations of the claims unless expressly set forth in the claims.

[0025] The terms "first" and "second" are used below to describe the elements of this application. These terms are used only to distinguish the individual elements and not to limit the nature, order, or number of these elements. The terms "comprising" and "having" are used to indicate an open-ended inclusion and mean that there may be additional elements / components besides those listed.

[0026] With the rapid development of new energy vehicles, the requirements for motor speed are becoming increasingly stringent, and the commonly used 8-pole permanent magnet synchronous motor can no longer meet market demands. Therefore, the 6-pole permanent magnet synchronous motor has gradually become the main type of motor used in domestic new energy hybrid vehicles. Considering the future application prospects of asynchronous motors in the new energy vehicle field, motor manufacturers have conducted research on asynchronous motors. This utility model proposes an improved asynchronous motor. Specifically, Figures 1 to 3 An asynchronous motor according to an embodiment of the present invention is shown, which is formed into a 6-pole asynchronous motor by a specific winding method of the stator winding. Compared with the prior art 8-pole asynchronous motor, the speed of the asynchronous motor can be increased to 1000 r / min.

[0027] like Figure 1 The asynchronous motor includes a stator assembly and a rotor assembly, wherein the stator assembly may include a stator core 1 and stator windings (not shown in the figure). The stator core 1 has a plurality of stator teeth 11 arranged at equal intervals along its circumference, each stator tooth 11 extending radially inward from the inner circumference of the stator core 1, thereby defining a stator slot 12 between every two adjacent stator teeth 11. The form, number, and arrangement of the winding conductors of the stator windings can be determined according to the type of motor and specific requirements. In the 6-pole asynchronous motor of this embodiment, the stator windings are arranged, for example, in the form of six layers of flat wire conductors within each stator slot 12.

[0028] like Figures 1 to 3 As shown, the rotor assembly may include a rotor core 2 and a rotor winding 3 (such as...). Figure 2 The rotor core 2 has a squirrel-cage winding (as shown) and is integrally disposed inside the stator core 1. Multiple rotor slots 21 are evenly spaced on its outer periphery, each slot 21 extending generally radially along the rotor core 2. A central through-hole is defined in the middle of the rotor core 2, and a rotor shaft 4 (see...) is disposed through this central through-hole. Figure 1 ).

[0029] For asynchronous motors, especially 6-pole asynchronous motors, a stator core 1 with 54 stator slots 12 can be selected. The 6-pole asynchronous motor proposed in this invention is preferably designed with 64 rotor slots 21. Thus, by utilizing the asynchronous motor structure with 54 stator slots 12 and 64 rotor slots 21, stray losses can be reduced, torque ripple can be significantly reduced, and the smoothness and NVH of the electric drive system can be improved.

[0030] To more clearly demonstrate that the asynchronous motor according to the embodiments of this utility model can achieve optimal motor performance, this utility model simulates the change of torque on the rotor with the rotor rotation angle when the number of rotor slots is 66 and 64, respectively, and finally obtains the following results: Figure 4 and Figure 5 The curve. Figure 4 The diagram illustrates the fluctuation of torque experienced by the rotor within one cycle when the number of rotor slots is 66. Figure 5 This diagram illustrates the fluctuation of the torque experienced by the rotor within one cycle when the number of rotor slots is 64.

[0031] from Figure 4 and Figure 5 As can be seen, the rotor rotates from 1080° to 1440° in one cycle. Within one cycle, the torque on the rotor changes with the rotor's rotation angle. For ease of description, the following will... Figure 4 The rotor shown is called a "66-slot rotor". Figure 5 The rotor shown is called a "64-slot rotor". Figure 4 Point a1 shows the lowest point of torque experienced by the 66-slot rotor in one cycle, and point a2 shows the highest point of torque experienced by the 66-slot rotor in one cycle. Therefore, the peak-to-peak value of the torque experienced by the 66-slot rotor (i.e., the difference between the maximum and minimum torque experienced by the rotor in one cycle) is 8.2 N·m. Figure 5 Point b1 shows the lowest torque experienced by the 64-slot rotor in one cycle, and point b2 shows the highest torque experienced by the 64-slot rotor in one cycle. Therefore, the peak-to-peak torque experienced by the 64-slot rotor is 3.5 N·m. This demonstrates that, compared to a 66-slot rotor, the rotor core 2 with 64 slots experiences fewer torque fluctuations and a smaller peak-to-peak torque. This reduces first- and second-order tooth harmonics in the rotor assembly, thereby lowering torque pulsation, improving motor operating stability, reducing noise, minimizing wear on mechanical components, and increasing motor lifespan.

[0032] Furthermore, in synchronous or asynchronous motors, factors such as magnetic circuit saturation, cogging effect, and harmonic magnetic fields can distort the air gap magnetic field, leading to torque components that differ from those under ideal operating conditions. This additional torque is known as synchronous additional torque. The presence of synchronous additional torque causes fluctuations in the motor's output torque, resulting in significant operating noise, affecting the motor's operational stability, and reducing motor efficiency. According to the asynchronous motor of this embodiment, by selecting 64 rotor slots 21, the generation of synchronous additional torque can be minimized. In addition, this specific structural form of the asynchronous motor (such as a 6-pole asynchronous motor with 54 stator slots and 64 rotor slots) can also reduce pulsation losses on the rotor surface, improve motor efficiency, and simultaneously achieve optimal noise and vibration levels (NVH).

[0033] The rotor slot 21 can be designed as an open slot or a closed slot. In the asynchronous motor according to an embodiment of this utility model, such as... Figure 2 As shown, the rotor slot 21 is preferably an open slot, which is formed by radially recessing from the outer peripheral wall of the rotor core 2 and having an open end at the outer peripheral wall of the rotor core 2, and the open slot extends from the first axial end of the rotor core 2 to the second axial end of the rotor core 2. A closed slot refers to a slot that extends radially and has a closed end at the outer peripheral wall of the rotor core (i.e., one end of the closed slot does not communicate with the outside of the rotor core). Figure 6 The peak torque curves obtained through simulation are shown for different configurations of rotor slot 21 in a 6-pole asynchronous motor with 54 stator slots and 64 rotor slots, where the rotor slot 21 is configured as an open slot and a closed slot, respectively. Curve c1 shows the peak torque as a function of speed when rotor slot 21 is a closed slot, and curve c2 shows the peak torque as a function of speed when rotor slot 21 is an open slot. Figure 6 It can be seen that when rotor slot 21 is an open slot, the peak torque can be increased by about 1.5% compared to when it is a closed slot.

[0034] Figure 7 It shows Figure 3 The enlarged cross-sectional view of part A of the asynchronous motor shown indicates that rotor slot 21 adopts the open slot form described above. It should be understood that, depending on specific design requirements, rotor slot 21 can preferably be configured as follows: Figure 2 The rotor slots, as shown, extend obliquely to form skewed slots. This skewed slot design effectively reduces cogging effects, makes the air gap magnetic field more uniform, and thus reduces synchronous additional torque. See also... Figure 7 The rotor slot 21 has a cross-section taken along a plane perpendicular to the axial direction of the rotor core 2. The cross-section of the open slot type rotor slot 21 may include an open section, a middle section and a tapering section in sequence along the radial direction inward of the rotor core 2.

[0035] The slot width of the open section is substantially constant radially inward along the rotor core 2, defining a first slot width L1. The slot width of the middle section gradually increases radially inward along the rotor core 2, and a pair of opposing stops 22 are defined at the portion of the rotor slot 21 corresponding to the middle section of its cross-section. The stops 22 can confine the cast conductor (such as aluminum or copper) within the rotor slot 21 during motor manufacturing, for example, when casting the conductor, to prevent process defects caused by the conductor detaching. Optionally, a rounded corner 23 can be formed at each stop 22 in the middle section, thereby giving the rotor slot 21 a smooth transition from the middle section to the tapering section. The slot width of the tapering section gradually decreases radially inward along the rotor core 2 to the end of the rotor slot 21. A second slot width L2, which is the maximum slot width, is defined at the transition between the middle section and the tapering section of the rotor slot 21. In the asynchronous motor of this invention, the ratio of the first slot width to the second slot width is preferably set to 0.7 to 0.8, which improves product quality and avoids any manufacturing defects. Therefore, such rotor slots 21 can further enhance motor performance.

[0036] As described above, the 6-pole asynchronous motor according to this embodiment may include a stator core with 54 stator slots and a rotor core with 64 rotor slots, which improves the component commonality between the 6-pole asynchronous motor and the 6-pole permanent magnet synchronous motor. Specifically, the 6-pole asynchronous motor and the 6-pole permanent magnet synchronous motor of this invention have the same rotor outer diameter, so the permanent magnet synchronous motor and the asynchronous induction motor can be switched by changing the rotor, which greatly improves the component commonality and reduces manufacturing and management costs.

[0037] This invention also provides a vehicle including the aforementioned asynchronous motor, such as a new energy vehicle.

[0038] As described above, the asynchronous motor according to this utility model can reduce stray losses through specific stator and rotor pole slot combinations, significantly reduce torque pulsation, improve the smoothness of electric drive system operation and NVH performance, and increase motor torque by setting the rotor slots as open slots. At the same time, it can also be used interchangeably with a 6-pole permanent magnet synchronous motor, thereby improving the versatility of parts and saving material costs.

[0039] Various modifications and variations can be made to the embodiments disclosed above without departing from the scope or spirit of this invention. Other embodiments of this invention will be apparent to those skilled in the art based on the practice of this invention disclosed in this specification. This specification and the examples disclosed herein should be considered illustrative only, and the true scope of this invention is defined by the appended claims and their equivalents.

Claims

1. An asynchronous motor, characterized in that, The asynchronous motor includes: A stator assembly comprising a stator core (1) having a plurality of stator teeth (11) arranged at equal intervals along its circumference, extending radially inward from its inner circumference, wherein a stator slot (12) is defined between every two adjacent stator teeth; and The rotor assembly includes a rotor core (2) having a plurality of radially extending rotor slots (21) arranged at equal intervals along its circumference. The asynchronous motor is a 6-pole asynchronous motor, which is designed to have 54 stator slots and 64 rotor slots.

2. The asynchronous motor according to claim 1, characterized in that, The rotor slot (21) is formed as an open slot that is radially recessed from the outer peripheral wall of the rotor core (2), and the open slot extends from the first axial end of the rotor core to the second axial end of the rotor core.

3. The asynchronous motor according to claim 2, characterized in that, The rotor slot (21) has a cross section taken along a plane perpendicular to the axial direction of the rotor core. The cross section of the rotor slot includes a tapering section, the width of which gradually decreases radially inward to the end of the rotor slot.

4. The asynchronous motor according to claim 3, characterized in that, The cross-section of the rotor slot also includes an open section and an intermediate section connecting the open section and the tapering section, wherein the slot width of the intermediate section gradually increases radially inward.

5. The asynchronous motor according to claim 4, characterized in that, The rotor slot has a pair of opposing stops (22) in the portion corresponding to the middle section of the cross section.

6. The asynchronous motor according to claim 5, characterized in that, Each of the stop portions (22) is formed with a rounded corner (23).

7. The asynchronous motor according to any one of claims 4 to 6, characterized in that, The slot width of the opening section is constant radially inward and defines a first slot width (L1). A second slot width (L2) is defined at the transition between the middle section and the tapered section of the rotor slot (21), wherein the ratio of the first slot width to the second slot width is 0.7 to 0.

8.

8. The asynchronous motor according to any one of claims 1 to 6, characterized in that, The stator core of the 6-pole asynchronous motor is configured to be compatible with the permanent magnet rotor of the 6-pole permanent magnet synchronous motor.

9. The asynchronous motor according to any one of claims 1 to 6, characterized in that, The stator assembly also includes a stator winding, wherein six layers of flat wire winding conductors are arranged in the stator slot.

10. A vehicle, characterized in that, Including the asynchronous motor according to any one of claims 1 to 9.

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