Rotor core, motor, and compressor

Abstract

The present disclosure relates to a rotor core, a motor and a compressor, the rotor core comprising a plurality of magnetic pole units distributed in a circumferential direction, the magnetic pole unit comprising a permanent magnet slot and a slit located on both sides of a center line of the magnetic pole unit, the slit being located on a side of the permanent magnet slot away from an axis of rotation of the rotor core, and the permanent magnet slot and the slit located on both sides of the center line being asymmetrically arranged. The technical scheme of the present disclosure effectively solves the technical problems of large motor torque ripple and large electromagnetic excitation force of a conventional motor.

Description

Technical Field

[0001] This disclosure relates to the field of motor technology, and in particular to a rotor core, a motor, and a compressor. Background Technology

[0002] With the continuous improvement of permanent magnet material performance and the development of motor technology, permanent magnet motors have been widely used in various sectors of the national economy. A permanent magnet motor consists of a stator structure, a rotor structure, and permanent magnets. Based on the connection position and method of the permanent magnets, the rotor structure of a permanent magnet motor can be divided into: surface-mounted permanent magnet rotors, surface-embedded permanent magnet rotors, and built-in permanent magnet rotors (intercalated permanent magnet rotors). In the built-in rotor structure, the magnetic field generated by the permanent magnet passes through the rotor core and then directly forms a circuit with the stator core through the air gap, generating torque.

[0003] However, due to the difficulty in adjusting the air gap magnetic field, and the fact that the toothed structure of the motor results in a large harmonic content in the air gap magnetic flux density and back electromotive force, the motor has large torque pulsation and large electromagnetic excitation force. Summary of the Invention

[0004] This disclosure provides a rotor core, a motor, and a compressor to solve the technical problems of large torque pulsation and large electromagnetic excitation force in traditional motors.

[0005] To this end, in a first aspect, the present disclosure provides a rotor core, including a plurality of magnetic pole units distributed along the circumferential direction. Each magnetic pole unit includes permanent magnet slots and slits located on both sides of the center line of the magnetic pole unit. The slits are located on the side of the permanent magnet slots away from the rotation axis of the rotor core. The permanent magnet slots and slits located on both sides of the center line are asymmetrically arranged.

[0006] In one possible implementation, the permanent magnet slot is provided with two slots, the slits include a first slit and a second slit, and the magnetic pole unit includes a first region and a second region located on both sides of the center line of the magnetic pole unit, the area of ​​the first region being larger than the area of ​​the second region.

[0007] Two permanent magnet slots are respectively located in the first region and the second region, and are arranged in a V-shape; at least one first slit is provided in the first region, and at least one second slit is provided in the second region.

[0008] In one possible implementation, the angle between the extension line of the first slit along its length and the center line of the magnetic pole unit is a first angle, and the angle between the extension line of the corresponding second slit along its length and the center line of the magnetic pole unit is a second angle, wherein the first angle is greater than the second angle.

[0009] In one possible implementation, the intersection of the extension line of the first slit along its length direction and the center line of the magnetic pole unit is located inside the magnetic pole unit, while the intersection of the extension line of the second slit along its length direction and the center line of the magnetic pole unit is located outside the magnetic pole unit.

[0010] In one possible implementation, a plurality of first slits are provided, and the plurality of first slits are spaced apart. In a first region, the first included angle of the first slits that are far from the center line of the magnetic pole unit gradually increases.

[0011] Multiple second slits are provided, and the multiple second slits are spaced apart. In the second region, the included angle of the second slits that are far from the center line of the magnetic pole unit gradually increases.

[0012] In one possible implementation, the difference between the first included angle and the second included angle is α, where α is greater than or equal to 5° and α is less than or equal to 45°.

[0013] In one possible implementation, the angle between the extension line of the permanent magnet slot in the length direction located in the first region and the center line of the magnetic pole unit is the third angle, and the angle between the extension line of the permanent magnet slot in the length direction located in the second region and the center line of the magnetic pole unit is the fourth angle, wherein the third angle is greater than the fourth angle.

[0014] In one possible implementation, the difference between the third included angle and the fourth included angle is γ, where γ is greater than 0° and less than or equal to 10°.

[0015] In one possible implementation, the width of the slit is d1, and the width of the permanent magnet slot is d2, wherein d1 is less than or equal to 1 / 2 * d2.

[0016] Secondly, this disclosure also provides an electric motor, comprising:

[0017] The rotor structure includes a rotor core as described above and a plurality of permanent magnets disposed in a plurality of permanent magnet slots within the rotor core; and

[0018] The stator structure is located on the outer periphery of the rotor structure.

[0019] Thirdly, this disclosure also provides a compressor, including the motor described above.

[0020] According to the rotor core, motor, and compressor provided in this disclosure, the rotor core includes multiple magnetic pole units distributed along the circumferential direction. Each magnetic pole unit includes permanent magnet slots and slits located on both sides of its centerline. The slits are located on the side of the permanent magnet slots away from the rotation axis of the rotor core. Both the permanent magnet slots and slits on both sides of the centerline are asymmetrically arranged. This technical solution, by setting asymmetrically distributed permanent magnet slots and slits, forms an asymmetrical magnetic pole structure on the rotor core, thereby achieving local adjustment of the magnetic path within the same magnetic pole unit. Compared to traditional rotor cores with symmetrically arranged permanent magnet slots and slits, this technical solution effectively avoids the problem of identical slit positions and sizes leading to identical magnetic conduction effects, which prevents targeted adjustment of the local magnetic reluctance distribution in the motor's magnetic path, greatly reducing the limitation of reducing torque ripple in the motor. Furthermore, the rotor core provided by this disclosed technical solution effectively improves the air gap magnetic field distribution, improves the air gap magnetic flux density waveform, reduces the cogging effect of the motor, reduces the torque pulsation of the motor, and reduces the electromagnetic vibration noise of the motor. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort. In addition, in the drawings, the same parts use the same reference numerals, and the drawings are not drawn to scale.

[0022] Figure 1 This is a schematic diagram of the rotor core provided in the first embodiment of the present disclosure;

[0023] Figure 2 A schematic diagram of auxiliary lines for the rotor core provided in the first embodiment of this disclosure;

[0024] Figure 3 for Figure 2 A magnified view of a portion of the image;

[0025] Figure 4 This is a schematic diagram of the rotor core provided in the second embodiment of the present disclosure;

[0026] Figure 5 for Figure 4 A magnified view of a portion of the image;

[0027] Figure 6 This is a partially enlarged view of the rotor core provided in the third embodiment.

[0028] Explanation of reference numerals in the attached figures:

[0029] 100. Rotor core;

[0030] 110. Magnetic pole unit; 111. Permanent magnet slot; 112. Slit; 1121. First slit; 1122. Second slit;

[0031] 200. Rotating shaft;

[0032] 300. Permanent magnet;

[0033] M, centerline; A, first zone; B, second zone;

[0034] a1, the first included angle; a2, the second included angle; a3, the third included angle; a4, the fourth included angle. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0036] Figure 1 A top view of the rotor core provided in the first embodiment of this disclosure is shown; Figure 2 An auxiliary line drawing showing a top view of the rotor core provided in the first embodiment of this disclosure; Figure 3 A partial enlarged view of the first embodiment provided in this disclosure is shown.

[0037] See Figures 1 to 3 This disclosure provides a rotor core, including a plurality of magnetic pole units 110 distributed along the circumferential direction. Each magnetic pole unit 110 includes permanent magnet slots 111 and slits 112 located on both sides of the center line M of the magnetic pole unit 110. The slits 112 are located on the side of the permanent magnet slots 111 away from the rotation axis 200 of the rotor core 100. The permanent magnet slots 111 and slits 112 located on both sides of the center line M are asymmetrically arranged.

[0038] In this embodiment, by setting asymmetrically distributed permanent magnet slots 111 and slits 112, an asymmetrical magnetic pole structure is formed on the rotor core 100, thereby achieving local adjustment of the magnetic path of the same magnetic pole unit 110. Compared with the traditional rotor core 100 with symmetrically arranged permanent magnet slots 111 and slits 112, this embodiment effectively avoids the phenomenon that the magnetic conduction effect is also the same due to the same position and size of the slits 112, making it impossible to specifically adjust the local magnetic reluctance distribution of the motor magnetic path, and greatly reducing the limitation of reducing motor torque ripple. Furthermore, the permanent magnet slots 111 and slits 112 on the magnetic pole unit 110 provided by this disclosure are all non-uniformly arranged, which effectively improves the air gap magnetic field distribution on the magnetic pole unit 110, improves the air gap magnetic flux density waveform, reduces the cogging effect of the motor, reduces the torque ripple of the motor, and reduces the electromagnetic vibration noise of the motor.

[0039] Specifically, the rotor core 100 is configured as a plurality of magnetic pole units 110, which include a plurality of N-pole magnetic pole units 110 and a plurality of S-pole magnetic pole units 110. The N-pole magnetic pole units 110 and the S-pole magnetic pole units 110 are alternately arranged, and the plurality of magnetic pole units 110 are arranged along the circumferential direction of the rotor core 100. Furthermore, the magnetic pole unit 110 includes a permanent magnet slot 111 for accommodating the permanent magnet 300 and a slit 112 for adjusting the magnetic field flow direction of the permanent magnet 300. The permanent magnet slot 111 and the slit 112 are asymmetrically distributed on both sides of the center line M of the magnetic pole unit 110. This forms different magnetic path regions and air gap magnetic flux density adjustment paths for different magnetic path regions, thereby overcoming the limitations of the uniformly symmetrically distributed permanent magnet 300 and magnetic isolation holes in reducing motor torque pulsation. This enables the adjustment of the magnetic path and air gap magnetic flux density at different positions of the magnetic pole unit 110, achieving local adjustment of the magnetic pole unit 110.

[0040] It needs further explanation that the center line M of the magnetic pole unit 110 is a radial line that divides a single magnetic pole unit 110 into two identical regions along the radial direction of the rotor core 100. Simultaneously, since the slit 112 contains non-magnetic materials such as air, its magnetic permeability is poor, its magnetic reluctance is high, and magnetic lines of force do not easily pass through. Therefore, by opening this slit 112, the magnetic reluctance distribution at various points in the magnetic circuit of the rotor core 100 can be altered, the direction of the yoke magnetic lines of force within the rotor core 100 can be changed, and the air gap magnetic flux density waveform can be improved. This reduces the proportion of back EMF harmonics, reduces motor torque pulsation, reduces electromagnetic force amplitude, and reduces motor electromagnetic vibration noise.

[0041] Furthermore, this embodiment asymmetrically arranges the permanent magnet slots 111 on both sides of the center line M, so that the two regions of the moving magnetic pole unit 110 (separated by its center line M) form an unbalanced magnetic field force. A larger magnetic field force is formed in one region, while a smaller magnetic field force is formed in the other region. This allows for adjustment of the magnetic flux at different positions on the magnetic pole unit 110. In addition, this embodiment asymmetrically arranges the slits 112 on both sides of the center line M to adjust the direction and flow of magnetic flux in different regions of the magnetic pole unit 110, thereby changing the magnetic field direction in that region. Then, by superimposing the changes in the magnetic field direction in multiple regions, the magnetic field direction of the magnetic pole unit 110 is improved. Furthermore, by superimposing the improvements in the air gap magnetic flux density in multiple regions, the air gap magnetic flux density within the magnetic pole unit 110 is improved.

[0042] According to the Fourier expansion formula of the air gap magnetic flux density waveform, the amplitude of each harmonic of the motor is directly proportional to the air gap magnetic field at that location. Increasing the width of the gap along the radial or axial direction of the rotor core helps to reduce the amplitude of each harmonic, thereby improving the air gap magnetic flux density at that location and enhancing the motor's running stability and other performance characteristics.

[0043] For example, but not limited to, the slit 112 is an elongated structure. Of course, in other embodiments, the slit 112 can also be other shapes, which are not limited here.

[0044] Figure 4 A top view of the rotor core provided in the second embodiment of this disclosure is shown; Figure 5 A partially enlarged view of the rotor core provided in the second embodiment of this disclosure is shown.

[0045] See Figures 1 to 5 In one possible implementation, the permanent magnet slot 111 is provided with two slots, the slit 112 includes a first slit 1121 and a second slit 1122, and the magnetic pole unit 110 includes a first region A and a second region B located on both sides of the center line M of the magnetic pole unit 110, wherein the area of ​​the first region A is larger than the area of ​​the second region B.

[0046] Two permanent magnet slots 111 are respectively located in the first region A and the second region B, and are arranged in a V-shaped structure; at least one first slit 1121 is provided in the first region A, and at least one second slit 1122 is provided in the second region B.

[0047] In this embodiment, the specific structure of the magnetic pole unit 110 is optimized. Specifically, the magnetic pole unit 110 is divided into a first region A and a second region B located on both sides of the center line M, with the area of ​​the first region A being larger than the area of ​​the second region B. Simultaneously, two permanent magnet slots 111 are arranged within the magnetic pole unit 110, located in the two regions respectively, and distributed in an asymmetrical V-shaped structure. This allows the magnetic pole unit 110 to adjust the magnetic flux flow direction, thereby forming two regions with different magnetic flux magnitudes, thus achieving adjustment of the magnetic flux magnitude in different regions of the magnetic pole unit 110. Furthermore, at least one first slit 1121 is arranged in the first region A, and at least one second slit 1122 is arranged in the second region B. By adjusting the magnetic path in different regions through the slits 112 in different regions, the magnetic flux flow direction is changed, thereby improving the air gap magnetic density in different regions, improving the air gap magnetic density of the entire magnetic pole unit 110, and further improving the air gap magnetic density of the rotor core 100.

[0048] See Figures 1 to 3 In a specific example, a first slit 1121 is provided in the first region A, and a second slit 1122 is provided in the second region B. At this time, the magnetic pole unit 110 includes two permanent magnet slots 111, a first slit 1121, and a second slit 1122. The two permanent magnet slots 111 are arranged in an inverted V-shape (which can also be described as a near-V-shaped structure), and the first slit 1121 and the second slit 1122 are arranged in a V-shape. The magnetic flux flows approximately along the length of the first slit 1121 / second slit 1122.

[0049] See Figure 4 and Figure 5 In another specific example, the first region A has two first slits 1121 and the second region B has two second slits 1122. At this time, the magnetic pole unit 110 includes two permanent magnet slots 111, two first slits 1121, and two second slits 1122. The two permanent magnet slots 111 are arranged in an inverted V-shape (or can be described as a near-V-shaped structure). One of the first slits 1121 and one of the second slits 1122 are arranged in a V-shape, and the other first slit 1121 and the other second slit 1122 are arranged in a V-shape and are located outside the first slit 1121 and the second slit 1122 arranged in a V-shape. The first slit 1121 and the second slit 1122 arranged in a V-shape near the center line M are steeper. This makes the dimensions of the slits 112 different in the radial and circumferential directions along the rotor core 100, but the same in the axial direction along the rotor core 100. This allows for the adjustment and improvement of the magnetic reluctance distribution at various points in the magnetic circuit, effectively adjusting the distribution of the air gap magnetic field and improving the air gap magnetic flux density waveform.

[0050] Of course, in other embodiments, the first slit 1121 in the first region A may be configured as multiple, in which case the second slit 1122 in the second region B is configured relative to the first slit 1121.

[0051] See Figure 3 and Figure 5 In one possible implementation, the angle between the extension line of the first slit 1121 along its length direction and the center line M of the magnetic pole unit 110 is a first angle a1, and the angle between the extension line of the corresponding second slit 1122 along its length direction and the center line M of the magnetic pole unit 110 is a second angle a2, wherein the first angle a1 is greater than the second angle a2.

[0052] In this embodiment, the positions of the first slit 1121 and the second slit 1122 are optimized. Specifically, the first slit 1121 located in the first region A is configured flat, while the second slit 1122 located in the second region B is configured steeply. That is, the first included angle a1 is greater than the second included angle a2. This allows the first slit 1121 located in the first region A to have a wider range of dimensional adjustment along the circumference of the rotor core 100, and the second slit 1122 located in the second region B to have a wider range of dimensional adjustment along the radial direction of the rotor core 100. This allows for targeted adjustment of the magnetic path in the first region A and the second region B, which is beneficial for improving adjustment accuracy and efficiency, and for reducing torque pulsation and electromagnetic excitation force.

[0053] See Figure 3 and Figure 5 In one possible implementation, the intersection of the extension line of the first slit 1121 in the longitudinal direction and the center line M of the magnetic pole unit 110 is located inside the magnetic pole unit 110, and the intersection of the extension line of the second slit 1122 in the longitudinal direction and the center line M of the magnetic pole unit 110 is located outside the magnetic pole unit 110.

[0054] In this embodiment, the inclination of the first slit 1121 and the second slit 1122 is optimized. Specifically, the intersection of the extension line of the first slit 1121 along its length direction and the center line M of the magnetic pole unit 110 is located inside the magnetic pole unit 110, while the intersection of the extension line of the second slit 1122 along its length direction and the center line M of the magnetic pole unit 110 is located outside the magnetic pole unit 110. This allows the magnetic field flowing through the first region A to be guided into the interior of the rotor core 100, and the magnetic field flowing through the second region B to be guided into the exterior of the rotor core 100. These two aspects complement each other, making the magnetic flux of the entire rotor core 100 smoother, greatly improving the air gap magnetic density, and significantly reducing the torque pulsation and electromagnetic excitation force of the motor.

[0055] See Figure 5In one possible implementation, a plurality of first slits 1121 are provided, and the plurality of first slits 1121 are spaced apart. Within the first region A, the first included angle α1 of the first slits 1121 that are far from the center line M of the magnetic pole unit 110 gradually increases.

[0056] Multiple second slits 1122 are provided, and the multiple second slits 1122 are spaced apart. In the second region B, the second included angle α2 of the second slits 1122 away from the center line M of the magnetic pole unit 110 gradually increases.

[0057] In this embodiment, the magnetic field flow direction in the first region A and the second region B is optimized. Specifically, multiple first slits 1121 and multiple second slits 1122 are configured, and the angle between the extension line of the slit 112 closer to the center line M and the center line M is smaller, while the angle between the extension line of the slit 112 further away from the center line M and the center line M is larger. This helps to concentrate the magnetic field far from the magnetic pole center line M onto the magnetic path at the middle position of the permanent magnet 300 (slot), thereby improving the magnetic focusing effect.

[0058] In one possible implementation, the difference between the first included angle a1 and the second included angle a2 is α, where α is greater than or equal to 5° and α is less than or equal to 45°.

[0059] In this embodiment, the relative positional relationship between the first slit 1121 and the second slit 1122 is optimized. Specifically, the first included angle α1 and the second included angle α2 are configured such that 5° ≤ the value of the first included angle α1 - the value of the second included angle α2 ≤ 45°. When the difference α between these two is less than 5°, local magnetic flux adjustment of the magnetic pole unit 110 cannot be achieved; when the difference α between these two is greater than 45°, the motor efficiency decays rapidly, severely affecting the motor performance. For example, but not limited to, the difference α between the first included angle α1 and the second included angle α2 is 30°.

[0060] Figure 6 A partially enlarged view of the rotor core provided in the third embodiment of this disclosure is shown.

[0061] See Figure 6 In one possible implementation, the angle between the extension line of the permanent magnet slot 111 in the length direction located in the first region A and the center line M of the magnetic pole unit 110 is the third angle a3, and the angle between the extension line of the permanent magnet slot 111 in the length direction located in the second region B and the center line M of the magnetic pole unit 110 is the fourth angle a4, wherein the third angle a3 is greater than the fourth angle a4.

[0062] In this embodiment, the relative positional relationship of the permanent magnet slots 111 is optimized. Specifically, the permanent magnet slots 111 in the larger first region A are set flat, while the permanent magnet slots 111 in the smaller second region B are set steeply, so that the magnetic pole region is divided into different areas by the center line M.

[0063] In one possible implementation, the difference between the third included angle a3 and the fourth included angle a4 is γ, where γ is greater than 0° and less than or equal to 10°.

[0064] In this embodiment, the relative positional relationship of the permanent magnet slots 111 in the first region A and the second region B is optimized to adjust the magnetic field flow direction. Specifically, the included angle between the two permanent magnets 300 is configured to be 0° < γ ≤ 10°. When the difference γ between the two is equal to 0°, local magnetic flux adjustment of the magnetic pole unit 110 cannot be achieved; when the difference γ is greater than 10°, the motor efficiency decays rapidly, seriously affecting the motor performance. For example, but not limited to, the difference γ between the third included angle a3 and the fourth included angle a4 is 5°.

[0065] In one possible implementation, the width of the slit 112 is d1, and the width of the permanent magnet slot 111 is d2, wherein d1 is less than or equal to 1 / 2 * d2.

[0066] In this embodiment, the widths of the slit 112 and the permanent magnet slot 111 are optimized to reduce magnetic path distortion and noise generated during motor operation. Specifically, the width of the slit 112 is configured such that d1 ≤ 1 / 2 * d2, thereby improving the efficiency of the magnetic field generated in the magnetic pole unit 110. When the width of the slit 112 is too large, it will lead to poor magnetic field flow, making the magnetic path prone to distortion, thus affecting motor performance. For example, but not limited to, the width of the slit 112 is half the width of the permanent magnet slot 111.

[0067] Figure 6 A partially enlarged view of the rotor core provided in the third embodiment of this disclosure is shown, wherein the large directional arrow shown in the figure indicates the rotation direction of the rotor core.

[0068] See Figure 6 In one possible implementation, the rotor core 100 rotates from the first region A to the second region B, thereby significantly reducing electrode torque pulsation and improving the practical performance of the motor by optimizing the rotation direction of the rotor core 100.

[0069] Secondly, this disclosure also provides an electric motor, comprising:

[0070] The rotor structure includes the rotor core 100 as described above and a plurality of permanent magnets 300 disposed in a plurality of permanent magnet slots 111 of the rotor core 100; and

[0071] The stator structure (not shown in the figure) is located on the outer periphery of the rotor structure.

[0072] In this embodiment, the specific structure of the rotor core 100 is the same as that in the above embodiments. Since this motor adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described in detail here.

[0073] Thirdly, this disclosure also provides a compressor, including the motor described above. The specific structure of the motor is as described in the above embodiments. Since this motor adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, and will not be described in detail here.

[0074] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0075] The above description is merely a specific embodiment of this disclosure, enabling those skilled in the art to understand or implement it. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A rotor core, characterized in that, It includes multiple magnetic pole units distributed along the circumferential direction. Each magnetic pole unit includes permanent magnet slots and slits located on both sides of the center line of the magnetic pole unit. The slits are located on the side of the permanent magnet slots away from the rotation axis of the rotor core. The permanent magnet slots and slits located on both sides of the center line are asymmetrically arranged. The permanent magnet slot is provided in two places, the slit includes a first slit and a second slit, and the magnetic pole unit includes a first region and a second region located on both sides of the center line of the magnetic pole unit, the area of ​​the first region is larger than the area of ​​the second region; The two permanent magnet slots are respectively disposed in the first region and the second region, and are arranged in a V-shaped structure; a plurality of first slits are provided in the first region, and a plurality of second slits are provided in the second region; The angle between the extension line of the first slit along its length and the center line of the magnetic pole unit is the first angle, and the angle between the extension line of the second slit along its length and the center line of the magnetic pole unit is the second angle, wherein the first angle is greater than the second angle. The intersection of the extension line of the first slit along its length direction and the center line of the magnetic pole unit is located inside the magnetic pole unit, and the intersection of the extension line of the second slit along its length direction and the center line of the magnetic pole unit is located outside the magnetic pole unit. Multiple first slits are spaced apart, and within the first region, the first included angle of the first slits away from the center line of the magnetic pole unit gradually increases; Multiple second slits are spaced apart, and within the second region, the included angle of the second slits away from the center line of the magnetic pole unit gradually increases; The difference between the first included angle and the second included angle is α, where α is greater than or equal to 5° and α is less than or equal to 45°.

2. The rotor core according to claim 1, characterized in that, The angle between the extension line of the permanent magnet slot in the first region and the center line of the magnetic pole unit is the third angle, and the angle between the extension line of the permanent magnet slot in the second region and the center line of the magnetic pole unit is the fourth angle, wherein the third angle is greater than the fourth angle.

3. The rotor core according to claim 2, characterized in that, The difference between the third included angle and the fourth included angle is γ, where γ is greater than 0° and less than or equal to 10°.

4. The rotor core according to claim 1, characterized in that, The width of the slit is d1, and the width of the permanent magnet groove is d2, wherein d1 is less than or equal to 1 / 2*d2.

5. An electric motor, characterized in that, include: The rotor structure includes a rotor core as described in any one of claims 1 to 4 and a plurality of permanent magnets disposed in a plurality of permanent magnet slots in the rotor core; and The stator structure is located on the outer periphery of the rotor structure.

6. A compressor, characterized in that, Includes the motor as described in claim 5.

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