Stator core, stator structure and motor

Abstract

The invention relates to the technical field of motor manufacturing, in particular to a stator core, a stator structure and a motor, the stator core comprises a stator yoke, and the stator yoke is of an annular structure; the tooth groove groups are sequentially and uniformly distributed on the inner wall of the stator yoke in the circumferential direction and extend inwards in the radial direction of the stator yoke, each tooth groove group comprises a plurality of stator teeth, a stator groove is formed between every two adjacent stator teeth, each stator tooth comprises a tooth root and a tooth tip, and the two ends of each tooth root are connected with the stator yoke and the tooth tip respectively; the tooth tips of at least part of the stator teeth in each tooth groove group are provided with grooves, and the structures of the grooves are different from each other. According to the invention, non-uniform magnetic conductance distribution can be realized, electromagnetic excitation of multiple orders is reduced, a weakening effect on various harmonic magnetic fields is achieved, and the vibration and noise performance of the motor is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor manufacturing, and in particular to a stator core, a stator structure and a motor. BACKGROUND

[0002] Electromagnetic excitation is the source of electromagnetic noise. When the motor is in operation, the corresponding order electromagnetic excitation is inevitably derived due to the existence of phase harmonic and stator tooth harmonic. Once the frequency of electromagnetic excitation matches the natural frequency of the system, the motor is prone to produce violent vibration and strong noise.

[0003] During the design of the motor scheme, electromagnetic excitation is a key factor that must be considered. The industry generally adopts the method of opening grooves on the outer wall of the rotor or the inner wall of the stator to improve the distribution of the magnetic field harmonic and thereby reduce the strength of the electromagnetic excitation. In particular, for the electromagnetic excitation caused by the stator tooth harmonic, the magnetic conductance can be optimized by opening grooves of the same specification on the stator to weaken the stator tooth harmonic. However, this method has obvious limitations and can only weaken the harmonic of the tooth number multiple. SUMMARY

[0004] The present application provides a stator core, a stator structure and a motor to solve the technical problem that it is difficult to weaken multiple orders of harmonics caused by stator tooth harmonics.

[0005] The present application provides a stator core, which comprises:

[0006] A stator yoke in a ring structure;

[0007] A plurality of tooth slot groups, each of which is uniformly distributed along the circumference of the inner wall of the stator yoke and extends inward along the radial direction of the stator yoke. Each tooth slot group comprises a plurality of stator teeth, and a stator slot is formed between adjacent stator teeth. Each stator tooth comprises a tooth root and a tooth tip, and the two ends of the tooth root are connected to the stator yoke and the tooth tip, respectively. A groove is formed on the tooth tip of at least part of the stator teeth in each tooth slot group, and the structures of the grooves are different from each other.

[0008] In an embodiment of the present application, the number of slots per pole per phase of the stator core is M, and M stator teeth form one tooth slot group.

[0009] In an embodiment of the present application, the groove structures of each stator tooth in each tooth slot group are different, and the groove structures of every M stator teeth are the same.

[0010] In an embodiment of the present application, the width of the slot opening of each groove along the circumferential direction of the stator yoke is W1, the width of the corresponding tooth root and tooth tip junction along the circumferential direction of the stator yoke is W2, and W1≤W2; the depth of each groove along the radial direction of the stator yoke is H1, and the thickness of the tooth tip along the radial direction of the stator yoke is T1, and H1≤3 / 4×T1.

[0011] In an embodiment of the present application, the grooves on adjacent stator teeth are of different slot types, or the grooves on adjacent stator teeth are of the same slot type but different sizes.

[0012] In an embodiment of the present application, the slot type cross section of the groove along the axial direction of the stator yoke comprises at least one of a triangle, a circular arc, a trapezoid, a rectangle, and a spline curve.

[0013] In an embodiment of the present application,

[0014] Each groove on the stator tooth is of a symmetric structure and is symmetrically arranged about the center plane of the corresponding stator tooth, and the center plane is a plane passing through the axis of the stator yoke;

[0015] Alternatively, each groove on the stator tooth is of a symmetric structure and is asymmetrically arranged about the center plane of the corresponding stator tooth, and the center plane is a plane passing through the axis of the stator yoke;

[0016] Alternatively, each groove on the stator tooth is of an asymmetric structure.

[0017] In an embodiment of the present application, the stator core is suitable for permanent magnet synchronous motors, reluctance motors, induction motors, and electrically excited motors.

[0018] The present application also provides a stator structure, comprising a winding and a stator core as described above, and the winding is wound on the stator core.

[0019] The present application also provides an electric machine, comprising a rotor structure and a stator structure as described above, and the rotor structure and the stator structure are magnetically coupled.

[0020] The present application has the following beneficial effects: the stator core, the stator structure, and the electric machine provided by the present application can realize uneven magnetic guide distribution by opening grooves of different structures on the tooth tips of at least part of the stator teeth in each tooth groove group, can reduce electromagnetic excitation of multiple orders, has weakening effect on various harmonic magnetic fields, and can comprehensively improve the vibration and noise performance of the electric machine. BRIEF DESCRIPTION OF DRAWINGS

[0021] The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate embodiments consistent with the application and, together with the description, further serve to explain the principles of the application. It is apparent that the drawing in the following description is only some embodiments of the present application, and other drawings can be obtained by those of ordinary skill in the art without creative labor on the basis of these drawings.

[0022] In the drawings:

[0023] Figure 1 A partial structure diagram of a stator core provided by an embodiment of the present application is shown.

[0024] Figure 2 A structure diagram of a tooth slot group of a stator core provided by an embodiment of the present application is shown.

[0025] Figure 3 A structure diagram of a tooth slot group of a stator core provided by another embodiment of the present application is shown.

[0026] Figure 4 A structure diagram of a tooth slot group of a stator core provided by yet another embodiment of the present application is shown.

[0027] Figure 5 A structure diagram of a tooth slot group of a stator core provided by still another embodiment of the present application is shown.

[0028] Figure 6 A partial structure diagram of a stator core provided by the prior art is shown.

[0029] Figure 7 Torque ripple waveforms of a stator tooth with different grooves and the same groove provided by an embodiment of the present application are shown.

[0030] Figure 8 Torque ripple spectrum diagrams of a stator tooth with different grooves and the same groove provided by an embodiment of the present application are shown.

[0031] Reference signs are as follows:

[0032] 1 - stator yoke;

[0033] 2 - stator tooth; 200 - tooth slot group; 21 - tooth root; 22 - tooth tip; 221 - groove; 221a - groove;

[0034] 3 - stator slot. DETAILED DESCRIPTION

[0035] The present application is illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements, and in which: Other advantages and novel features of the present application will become apparent from the following detailed description, when considered in conjunction with the non-limiting drawings.

[0036] To clearly illustrate embodiments of the present application or technical solutions in the prior art, a brief description will be given below with reference to the drawings wherein:

[0037] In the following description, numerous specific details are discussed in order to provide a thorough understanding of embodiments of the present application. However, those of ordinary skill in the art will realize that the embodiments of the present application can be practiced without many of these specific details. In other instances, well-known structures and devices are not described in detail in order to avoid obscuring embodiments of the present application. An element or component will be "operatively coupled" or "operatively connected," if such a relationship is facilitated, whether directly or indirectly via one or more other functions, devices, circuits, etc.

[0038] Reference will now be made to the drawings, wherein: Figure 1 Figure 1 A schematic diagram of a part of a stator core according to an embodiment of the present application is shown in FIG. 1, which includes a stator yoke 1 and a plurality of tooth slot groups 200. The stator yoke 1 is in a ring structure. The tooth slot groups 200 are evenly distributed along the circumference of the stator yoke 1 and extend inward along the radial direction of the stator yoke 1. Each tooth slot group 200 includes a plurality of stator teeth 2, and a stator slot 3 is formed between adjacent stator teeth 2. Each stator tooth 2 includes a tooth root 21 and a tooth tip 22. The two ends of the tooth root 21 are connected to the stator yoke 1 and the tooth tip 22, respectively. A groove 221 is formed on the tooth tip 22 of at least part of the stator teeth 2 in each tooth slot group 200. The structures of the grooves 221 are different from each other. Figure 1

[0039] ​​Specifically, the stator yoke 1 is annular structure, which provides stable support for the whole stator core. A stator inner hole (not shown in the figure) is arranged in the middle of the stator yoke 1, which is used for the rotor structure to pass through and rotate in the stator inner hole. Each tooth slot group 200 is arranged on the inner wall of the stator yoke 1 in sequence along the circumferential direction, that is, arranged repeatedly along the circumferential direction of the stator yoke 1. The stator teeth 2 are arranged in plurality along the circumferential direction of the stator yoke 1, and each stator tooth 2 extends along the radial direction towards the stator inner hole of the stator yoke 1. The uniformly distributed stator teeth 2 help to form a more uniform magnetic field in the motor air gap. The inner side end surface of each stator tooth 2 is located on a cylindrical side surface coaxial with the stator yoke 1, and the inner side end surface of the stator tooth 2 is arc-shaped. The stator yoke 1 and the stator teeth 2 are integrally formed, which is beneficial to increase the strength of the whole stator core.

[0040] Each stator tooth 2 includes a tooth root 21 and a tooth tip 22. The first end of the tooth root 21 is connected with the stator yoke 1, and the second end (opposite to the first end) of the tooth root 21 is connected with the tooth tip 22. The plurality of stator teeth 2 are arranged in plurality along the circumferential direction of the stator yoke 1, so that the tooth tips 22 of the plurality of stator teeth 2 enclose the stator inner hole.

[0041] The tooth tip 22 of at least part of the stator teeth 2 in each tooth slot group 200 is provided with a groove 221, that is, one of the stator teeth 2 in a tooth slot group 200 can not be provided with a groove 221, and the remaining stator teeth 2 are provided with grooves 221; or, all the stator teeth 2 in a tooth slot group 200 can be provided with grooves 221. The structures of the grooves 221 are different from each other, and the grooves 221 are located on the inner side end surface of the tooth tip 22. The groove mouth of the groove 221 faces away from the tooth root 21, and the groove 221 is arranged through along the thickness direction of the stator tooth 2.

[0042] By providing the groove 221 on the tooth tip 22 of the stator tooth 2, the harmonic of the stator tooth 2 can be weakened. By providing the grooves 221 with different structures on the tooth tips 22 of the stator teeth 2 in each tooth slot group 200, it is beneficial to realize the uneven magnetic conductive distribution, which has a weakening effect on various harmonic magnetic fields, and improves the noise and vibration performance of the motor.

[0043] This structure can specifically weaken the electromagnetic excitation of various orders generated during the operation of the motor. The grooves 221 with different structures will have different modulation effects on the air gap magnetic field. By destroying the orderliness of the harmonic magnetic field generated by the electromagnetic excitation, the amplitude of the specific order harmonic is reduced. The design of the grooves 221 with different structures can effectively weaken the strength of the electromagnetic excitation, thereby reducing the strong vibration and noise caused by the consistency of the electromagnetic excitation and the system inherent frequency.

[0044] And by setting different structure grooves 221 on the tooth tips 22, the distribution of the air gap magnetic field can be improved, and the harmonic components in the air gap magnetic field are more reasonable. Compared with the traditional stator core, this design can significantly reduce the content of high-order harmonics, making the air gap magnetic field closer to a sine wave. The sine wave air gap magnetic field can reduce the iron loss and copper loss during motor operation, improve the efficiency of the motor, and also reduce the electromagnetic noise and vibration level of the motor, improving the overall performance of the motor.

[0045] The tooth tips 22 of adjacent stator teeth 2 are provided with grooves 221 of different structures, which can be optimized and adjusted according to the design requirements and application scenarios of the stator core in different motors. Whether it is a motor with different pole numbers and slot numbers, or a motor with special performance requirements, the structure and parameters of the reasonably designed grooves 221 can effectively weaken the electromagnetic excitation and optimize the air gap magnetic field, thereby improving the performance and adaptability of the motor.

[0046] In some embodiments, the number of slots per pole per phase of the stator core is M, and M stator teeth 2 form one tooth slot group 200. For example, taking a 6-pole 54-slot motor as an example, the number of slots per pole per phase is 3, and every 3 stator teeth 2 form a tooth slot group 200, as shown in Figure 2 Each tooth slot group 200 is arranged in sequence along the circumference of the stator yoke 1, i.e., arranged in sequence along the circumference of the stator yoke 1. When M stator teeth 2 form one tooth slot group 200, this grouping provides an orderly structural basis for magnetic field modulation. The layout of each tooth slot group 200 arranged in sequence along the circumference of the stator yoke 1 makes the magnetic field distribution inside the motor more uniform and reasonable. This orderly arrangement can reduce magnetic field distortion and reduce the harmonic content of the magnetic field, thereby effectively improving the electromagnetic performance of the motor

[0047] In the above embodiments, the grooves 221 of each stator tooth 2 in each tooth slot group 200 are different in structure, and the grooves 221 of every M stator teeth 2 are the same in structure.

[0048] Specifically, as shown in Figure 2 Taking a 6-pole 54-slot motor as an example, the number of slots per pole per phase is 3, i.e., every 3 stator teeth 2 form a tooth slot group 200, and the grooves 221 of the 3 stator teeth 2 in each tooth slot group 200 are different in structure. In this example, the groove types of the 3 stator teeth 2 in the tooth slot group 200 are triangle, circular arc, and trapezoid, respectively.

[0049] Furthermore, the groove 221 structure of every 3 stator teeth 2 is the same, that is, the groove 221 structure of the 1st stator tooth 2, the 4th stator tooth 2, the 7th stator tooth 2, the 10th stator tooth 2... is the same, the groove 221 structure of the 2nd stator tooth 2, the 5th stator tooth 2, the 8th stator tooth 2, the 11th stator tooth 2... is the same, and the groove 221 structure of the 3rd stator tooth 2, the 6th stator tooth 2, the 9th stator tooth 2, the 12th stator tooth 2... is the same.

[0050] The above settings apply to all motors with an integer number of slots per pole per phase greater than 1. For example, in an 8-pole 48-slot motor, the number of slots per pole per phase is 2. In this case, 2 stator teeth 2 form a tooth slot group 200. The groove 221 structure on the surface of the tooth tip 22 of two adjacent stator teeth 2 within each tooth slot group 200 is different, while the groove 221 structure on the surface of the tooth tip 22 of every two stator teeth 2 is the same. For example, in a 6-pole 72-slot motor, the number of slots per pole per phase is 4. In this case, 4 stator teeth 2 form a tooth slot group 200. The groove 221 structure on the surface of the tooth tip 22 of four adjacent stator teeth 2 within each tooth slot group 200 is different, while the groove 221 structure on the surface of the tooth tip 22 of every four stator teeth 2 is the same.

[0051] Thus, the tooth group 200 composed of different groove 221 structures helps to achieve a non-uniform magnetic permeability distribution, which can reduce electromagnetic excitation of multiple orders and weaken various harmonic magnetic fields. Furthermore, the combination of stator teeth 2 with different groove 221 structures helps to improve the magnetic permeability utilization rate of the iron core. During motor operation, magnetic lines of force can be conducted more efficiently in stator teeth 2 with different groove 221 structures, reducing magnetic resistance and allowing more magnetic energy to be converted into mechanical energy, further improving the motor's power output capability.

[0052] It should be noted that the width of the groove opening of each groove 221 along the circumference of the stator yoke 1 is W1, and the width of the corresponding connection between the tooth root 21 and the tooth tip 22 along the circumference of the stator yoke 1 is W2, therefore W1≤W2. Specifically, the stator teeth 2 are subjected to various forces such as electromagnetic force and mechanical vibration during motor operation. If the groove opening width W1 of the groove 221 is greater than the width W2 at the connection between the tooth root 21 and the tooth tip 22, a significant stress concentration area will be formed at the edge of the groove. When the motor operates at high speed or is subjected to a large load, this stress concentration may cause cracks or even breakage in the teeth. The design that satisfies W1≤W2 allows the stress to be distributed more evenly in the teeth, improving the structural strength and reliability of the teeth. The magnetic field in the motor needs to form a closed loop through the stator teeth 2. If W1 is too large, it will disrupt the continuity of the magnetic circuit, increase magnetic reluctance, and lead to uneven magnetic field distribution, affecting the performance of the motor. Maintaining W1≤W2 helps to maintain the smoothness of the magnetic circuit, reduce magnetic leakage, and improve the efficiency of the motor.

[0053] In the above embodiment, the depth of each groove 221 along the radial direction of the stator yoke 1 is H1, and the thickness of the tooth tip 22 along the radial direction of the stator yoke 1 is T1, then H1 ≤ 3 / 4 × T1. Specifically, the tooth tip 22 is the part of the stator tooth 2 that bears a large electromagnetic force. If the depth H1 of the groove 221 is too large, it will weaken the mechanical strength of the tooth tip 22, making it prone to deformation under the action of electromagnetic force. When the tooth tip 22 is severely deformed, it will lead to uneven air gap, affecting the performance and operational stability of the motor. The design of H1 ≤ 3 / 4 × T1 can ensure that the tooth tip 22 has sufficient thickness and strength to resist the action of electromagnetic force and maintain the uniformity of the air gap.

[0054] It is understandable that the grooves 221 on adjacent stator teeth 2 have different groove shapes, or that the grooves 221 on adjacent stator teeth 2 have the same groove shape but different dimensions.

[0055] For details, please refer to Figure 2 The grooves 221 on adjacent stator teeth 2 have different groove shapes. For example, the grooves 221 on adjacent stator teeth 2 can be triangular, arc-shaped, or trapezoidal, respectively. Alternatively, other groove shapes are also possible, and no specific limitation is imposed.

[0056] Or, see Figure 3 The grooves 221 on adjacent stator teeth 2 have the same groove shape but different dimensions. For example, the grooves 221 on adjacent stator teeth 2 are all triangular, but the triangle dimensions of each groove 221 are different, forming triangular grooves 221 of different specifications.

[0057] Thus, when the grooves 221 on adjacent stator teeth 2 have different slot shapes or sizes, the periodicity of the magnetic field distribution will be disrupted. In traditional designs, if the groove structure 221 on all stator teeth 2 is identical, the magnetic field will generate strong harmonic components at specific frequencies. These harmonic magnetic fields will cause additional losses and vibrations in the motor. However, using grooves 221 with different slot shapes or sizes will change the propagation path and magnetic reluctance of the magnetic field, causing the harmonic magnetic fields to interfere with and cancel each other during propagation, thereby effectively weakening the influence of the harmonic magnetic field. Furthermore, different groove shapes and sizes will have different guiding effects on the direction and distribution of the magnetic field. By rationally combining the grooves 221 on adjacent stator teeth 2, the magnetic field can be more evenly distributed in the air gap, thereby helping to reduce torque pulsation during motor operation and improve the smoothness of motor operation.

[0058] In some embodiments, along the axial direction of the stator yoke 1, the groove cross-section of the groove 221 includes at least one of the following: triangular, arc-shaped, trapezoidal, rectangular, and spline curve.

[0059] Specifically, the groove 221 includes a triangular groove 221. The apex of the triangular groove 221 faces the tooth root 21, and the two sides of the triangle form an included angle, with both sides located on the inner end face of the tooth tip 22. The triangular groove 221 helps to alter the distribution of the air gap magnetic field and weaken the harmonic magnetic field.

[0060] The groove 221 also includes an arc-shaped groove 221. The bottom wall of the arc-shaped groove 221 is arc-shaped, and in some embodiments, at least one side wall of the arc-shaped groove 221 is arc-shaped.

[0061] The groove 221 also includes a trapezoidal groove 221. The bottom wall of the trapezoidal groove 221 is a straight bottom wall, and the side walls of the trapezoidal groove 221 are also straight side walls, and there is a non-90° included angle between the side walls and the bottom wall.

[0062] The groove 221 also includes a rectangular groove 221. The bottom wall of the rectangular groove 221 is a flat bottom wall, and the side walls of the rectangular groove 221 are also flat side walls, and the angle between the side walls and the bottom wall is a right angle.

[0063] The groove 221 also includes a spline curve groove 221. The groove 221 can be an irregularly shaped groove 221, and its specific shape is not limited. The spline curve groove 221 has high flexibility, and can be designed with any shape of groove cross-section according to the specific performance requirements of the motor, enabling precise control of the magnetic field distribution and reducing electromagnetic force fluctuations.

[0064] It is understood that the various grooves 221 mentioned above can be symmetrical or asymmetrical structures, and the specific shape of the grooves 221 is not limited in the embodiments of the present invention. By setting grooves 221 with different groove shapes, it is possible to weaken harmonic magnetic fields of specific orders, optimize the harmonic content of the air gap magnetic field, and improve the vibration and noise performance of the motor.

[0065] In some implementations, see Figure 2 The grooves 221 on each stator tooth 2 are symmetrical in structure and arranged symmetrically about the central plane of the corresponding stator tooth 2, which is a plane passing through the axis of the stator yoke 1. Specifically, the symmetrical design of the grooves 221 makes the magnetic field distribution on both sides of the stator tooth 2 more uniform. Thus, symmetrically arranging the grooves 221 with the plane passing through the axis of the stator yoke 1 as the central plane ensures the symmetry of the magnetic field in the air gap and reduces magnetic field distortion. The symmetrical groove structure 221 has a good suppression effect on magnetic field harmonics. Because the magnetic field is symmetrically distributed on both sides, harmonics of certain orders will cancel each other out during propagation, thereby reducing the harmonic content.

[0066] Alternatively, in some other implementations, see [reference] Figure 4Each stator tooth 2 has a symmetrical groove 221, which is asymmetrically positioned about the center plane of the corresponding stator tooth 2. This center plane is a plane passing through the axis of the stator yoke 1. Specifically, the symmetrical plane of the groove 221 has an angle with the center plane of the corresponding stator tooth 2; that is, the groove 221 itself is a symmetrical structure, but its arrangement is asymmetrical with respect to the center plane of the stator tooth 2. Thus, although the groove 221 itself is a symmetrical structure, the asymmetrical arrangement allows for the directional guidance of the magnetic field. By adjusting the position and angle of the groove 221 relative to the center plane, the distribution of the magnetic field in the air gap can be changed; the asymmetrical arrangement can also change the distribution and intensity of magnetic field harmonics.

[0067] Alternatively, in some other implementations, see [reference] Figure 5 Each stator tooth 2 has an asymmetrical groove 221. That is, the groove 221 itself is asymmetrical. The asymmetrical groove 221 can be customized according to the specific performance requirements of the motor. The asymmetrical groove 221 can change the magnetic field coupling mode between the stator tooth 2 and the rotor, so that the stator tooth 2 can better adapt to complex mechanical conditions.

[0068] Understandably, the aforementioned stator core is suitable for permanent magnet synchronous motors, reluctance motors, induction motors, and electrically excited motors. It can reduce electromagnetic excitation of multiple orders, weaken various harmonic magnetic fields, and improve motor vibration and noise performance.

[0069] The optimization effect of the stator core on electromagnetic excitation in this invention is illustrated using a 6-pole, 54-slot motor as an example. Figure 1 As shown, this is a partial structural diagram of a stator core provided in an embodiment of the present invention. Different groove structures 221 are provided on three adjacent stator teeth 2 of the stator core; as... Figure 6 As shown, this is a partial structural diagram of a stator core in the prior art. The stator core includes a stator yoke 1 and multiple stator teeth 2. Each stator tooth 2 includes a tooth root 21 and a tooth tip 22, and each stator tooth 2 has a groove 221a with the same structure. The torque pulsation of two motors using different stator cores is simulated under the same boundary conditions, such as... Figure 7 The diagram shown is a waveform representation of torque ripple. Figure 8 The image shows the torque ripple spectrum after Fourier decomposition of the torque ripple.

[0070] It can be seen that the proposed solution of creating grooves 221 with different structures on adjacent stator teeth 2, compared with the traditional solution of creating grooves 221 with the same structure on adjacent stator teeth 2, can reduce electromagnetic excitation of several orders, specifically as follows:

[0071] For a motor with the same groove 221 for stator teeth 2, the peak-to-peak torque ripple is 4.9 Nm, the 18th-order torque ripple is 1.96 Nm, and the 36th-order torque ripple is 1.15 Nm.

[0072] For motors with different groove structures 221 for stator teeth 2, the peak-to-peak torque ripple is 3.5 Nm, the 18th-order torque ripple is 0.72 Nm, and the 36th-order torque ripple is 0.59 Nm.

[0073] The comparison showed that the torque ripple of the 18th order was reduced by 63.3% and the torque ripple of the 36th order was reduced by 48.7%, demonstrating a significant improvement.

[0074] The present invention also provides a stator structure, which includes: a winding and a stator core as described above, wherein the winding is wound on the stator core.

[0075] The present invention also provides an electric motor, which includes: a rotor structure and a stator structure as described above, wherein the rotor structure and the stator structure are magnetically coupled.

[0076] In summary, the stator core, stator structure, and motor provided by the present invention achieve a non-uniform magnetic permeability distribution by opening grooves of different structures on the tips of at least some stator teeth in each tooth slot group. This reduces electromagnetic excitation of multiple orders and weakens various harmonic magnetic fields, thereby comprehensively improving the vibration and noise performance of the motor.

[0077] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A stator core, characterized in that, include: Stator yoke, wherein the stator yoke has a ring-shaped structure; Multiple tooth groove groups are arranged circumferentially on the inner wall of the stator yoke and extend radially inward along the stator yoke. Each tooth groove group includes several stator teeth, and stator grooves are formed between adjacent stator teeth. Each stator tooth includes a tooth root and a tooth tip. The two ends of the tooth root are respectively connected to the stator yoke and the tooth tip. At least some of the stator teeth in each tooth groove group have grooves on their tooth tips, and the structures of each groove are different.

2. The stator core according to claim 1, characterized in that, The number of slots per pole and per phase of the stator core is M, and M stator teeth form one slot group.

3. The stator core according to claim 2, characterized in that, The groove structure of each stator tooth in each of the tooth groups is different, while the groove structure of each M stator teeth is the same.

4. The stator core according to claim 1, characterized in that, The width of the groove opening along the circumferential direction of the stator yoke is W1, and the width of the corresponding tooth root and tooth tip connection along the circumferential direction of the stator yoke is W2, so W1≤W2; the depth of each groove along the radial direction of the stator yoke is H1, and the thickness of the tooth tip along the radial direction of the stator yoke is T1, so H1≤3 / 4×T1.

5. The stator core according to claim 1, characterized in that, The grooves on adjacent stator teeth have different groove shapes, or the grooves on adjacent stator teeth have the same groove shape but different sizes.

6. The stator core according to claim 1 or 5, characterized in that, Along the axial direction of the stator yoke, the groove cross-section includes at least one of triangle, arc, trapezoid, rectangle, and spline curve.

7. The stator core according to claim 1, characterized in that, The grooves on each stator tooth are symmetrical and arranged symmetrically about the center plane of the corresponding stator tooth, which is a plane passing through the stator yoke axis; Alternatively, the grooves on each stator tooth are symmetrical and asymmetrically arranged about the center plane of the corresponding stator tooth, the center plane being a plane passing through the stator yoke axis; Alternatively, the grooves on each of the stator teeth may be asymmetrical.

8. The stator core according to claim 1, characterized in that, The stator core is suitable for permanent magnet synchronous motors, reluctance motors, induction motors, and electrically excited motors.

9. A stator structure, characterized in that, include: The winding and the stator core as described in any one of claims 1-8, wherein the winding is wound on the stator core.

10. An electric motor, characterized in that, include: The rotor structure and the stator structure as described in claim 9, wherein the rotor structure and the stator structure are magnetically coupled.

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