Stator cores, motors, compressors, and air conditioners

Abstract

The present application provides a stator core, a motor, a compressor, and an air conditioner. The stator core comprises stator teeth (1), wherein the inner circumference of at least part of the stator teeth (1) is provided with a first slot (2) and a second slot (3), wherein the first slot (2) is located at the first end of the stator core, and the second slot (3) is located at the second end of the stator core. The first slot (2) and the second slot (3) are staggered along the circumference of the stator core, and the sum of the axial heights of the first slot (2) and the second slot (3) is the axial height of the stator core. According to the stator core of the present application, the cogging torque of the motor can be more effectively reduced, and the torque pulsation and vibration noise of the motor can be reduced.

Description

Technical Field

[0001] The present application relates to the technical field of motors, and in particular to a stator core, a motor, a compressor and an air conditioner. Background Art

[0002] Cogging torque is the force torque generated by the interaction between the permanent magnets and the stator core of a permanent magnet motor (PMM) when the windings are deenergized. It is caused by the tangential component of the interaction force between the permanent magnets and the armature teeth and is one of the main sources of torque ripple in PMM motors. For existing motors, cogging torque is a critical parameter affecting positioning accuracy. It can cause rotor speed fluctuations, induce motor vibration and noise, and impact system control accuracy.

[0003] Related art discloses a stator core with a double-slot structure, which affects the torque pulsation of the motor by opening 1 to 3 virtual slots on the teeth, wherein the single slot is located at the center of the stator teeth and the two slots are evenly distributed on the stator teeth.

[0004] The stator core in this scheme has a double-slot structure that is a through-slot structure. This structure simply limits the cogging torque by increasing the least common multiple of the number of stator slots and the number of pole pairs. As a result, the grooves on the teeth have a limited effect on reducing the cogging torque of the motor, causing the torque pulsation and vibration noise of the motor to remain large. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present application is to provide a stator core, a motor, a compressor and an air conditioner that can more effectively reduce the cogging torque of the motor and reduce the motor torque pulsation and vibration noise.

[0006] In order to solve the above problems, the present application provides a stator core, including stator teeth, wherein the inner circumferential surface of at least part of the stator teeth is provided with a first slot and a second slot, the first slot is located at the first end of the stator core, and the second slot is located at the second end of the stator core. The first slot and the second slot are staggered along the circumference of the stator core, and the sum of the axial heights of the first slot and the second slot is the axial height of the stator core.

[0007] Preferably, the included angle between adjacent side edges of two adjacent stator teeth along the circumferential direction of the stator core is A, and the included angle between the first slot and the second slot along the circumferential direction of the stator core is a1, and 3≤a1 / A≤4.5.

[0008] Preferably, the minimum slot width of the first slot and the second slot is b2, the maximum slot width is b1, and 0.1≤b2 / b1≤0.9.

[0009] Preferably, the maximum slot width of the first slot and the second slot is b1, the slot width between two adjacent stator teeth is B, and 0.5≤b1 / B≤0.75.

[0010] Preferably, the inner circumferential surface of each stator tooth is provided with a first groove and a second groove.

[0011] Preferably, the inner circumferential surface of some stator teeth is provided with a first groove and a second groove penetrating in the axial direction.

[0012] Preferably, the number of stator teeth is odd, one stator tooth is provided with a third slot that passes through the stator core along the axial direction of the stator core, the third slot is located on the center line of the stator tooth, the stator teeth on both sides of the stator tooth are provided with a first slot and a second slot, and the stator teeth on both sides of the stator tooth are symmetrical about the center line of the stator tooth.

[0013] Preferably, the angle bisector between the first slot and the second slot coincides with the center line of the stator tooth.

[0014] Preferably, the angle bisector between the first slot and the second slot is offset to one side relative to the center line of the stator tooth.

[0015] Preferably, the inner circumferential surface of the stator tooth is further provided with a fourth slot, which is located in the axial middle of the stator core and between the first slot and the second slot along the circumferential direction.

[0016] Preferably, the stator core includes a first core punching sheet, which is provided with a first punching sheet slot. A portion of the first core punching sheets is stacked to form a first slot, and another portion of the first core punching sheets is flipped and stacked to form a second slot. All the core punching sheets are stacked together and fixedly connected.

[0017] Preferably, the stator core includes a first core punching sheet and a second core punching sheet, the first core punching sheet is provided with a first punching sheet slot, a portion of the first core punching sheets are stacked to form a first slot, and another portion of the first core punching sheets are flipped and stacked to form a second slot, the second core punching sheet is provided with a first punching sheet slot and a second punching sheet slot, and the second core punching sheets are stacked to form a first slot and a fourth slot.

[0018] According to another aspect of the present application, a motor is provided, including a stator core, which is the stator core described above.

[0019] According to another aspect of the present application, a compressor is provided, comprising a motor, which is the motor described above.

[0020] According to another aspect of the present application, an air conditioner is provided, comprising a motor, which is the above-mentioned motor.

[0021] The stator core provided herein includes stator teeth, wherein the inner circumferential surfaces of at least some of the stator teeth are provided with first and second slots, the first slot being located at a first end of the stator core, and the second slot being located at a second end of the stator core. The first and second slots are staggered circumferentially about the stator core, and the sum of the axial heights of the first and second slots is the axial height of the stator core. By forming the first and second slots staggered circumferentially and axially on the inner circumferential surfaces of the stator teeth, the stator core can utilize the circumferential and axial offsets of the first and second slots to form a simple axial skew slot, thereby creating a skew slot effect, optimizing the magnetic field and electric potential, and thereby more effectively reducing the cogging torque of the motor, as well as reducing torque pulsation and vibration noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic structural diagram of a stator core according to an embodiment of the present application;

[0023] Figure 2 This is a schematic diagram of the three-dimensional structure of the stator core according to one embodiment of the present application;

[0024] Figure 3 This is a schematic diagram of the three-dimensional structure of the stator core according to one embodiment of the present application;

[0025] Figure 4 This is a schematic diagram of the three-dimensional structure of the stator core according to one embodiment of the present application;

[0026] Figure 5 This is a schematic cross-sectional view of a stator core according to an embodiment of the present application;

[0027] Figure 6 This is a schematic diagram of the punching structure of the stator core according to one embodiment of the present application;

[0028] Figure 7 This is a schematic diagram of the punching structure of the stator core according to one embodiment of the present application;

[0029] Figure 8 This is a comparison diagram of the cogging torque PK-PK values ​​of a motor according to an embodiment of the present application and a motor in the related art;

[0030] Figure 9 This is a diagram showing the effect of the cogging torque PK-PK value changing with the slot width and slot spacing when the slot depth is fixed for a motor according to an embodiment of the present application;

[0031] Figure 10 This is a diagram showing how the cogging torque PK-PK value changes with the slot depth and slot spacing when the slot width is fixed for a motor according to one embodiment of the present application.

[0032] The reference numerals indicate:

[0033] 1. Stator tooth; 2. First slot; 3. Second slot; 4. Third slot; 5. Fourth slot. DETAILED DESCRIPTION

[0034] See also Figures 1 to 10 As shown, according to an embodiment of the present application, the stator core includes stator teeth 1, and the inner circumferential surface of at least part of the stator teeth 1 is provided with a first slot 2 and a second slot 3. The first slot 2 is located at the first end of the stator core, and the second slot 3 is located at the second end of the stator core. The first slot 2 and the second slot 3 are staggered along the circumference of the stator core, and the sum of the axial heights of the first slot 2 and the second slot 3 is the axial height of the stator core.

[0035] The stator core forms first and second slots that are circumferentially and axially offset on the inner circumferential surface of the stator teeth. The circumferential arrangement of the first and second slots can effectively increase the least common multiple of the number of stator slots and the number of pole pairs, increase the harmonic order of the cogging torque, and reduce the cogging torque amplitude. In addition, the axial offset structure of the first and second slots can form a simple skew slot effect on the basis of increasing the least common multiple, optimize the magnetic field and electric potential, and thus more effectively reduce the cogging torque of the motor, and reduce the torque pulsation and vibration noise of the motor.

[0036] In one embodiment, the angle between the adjacent side edges of two adjacent stator teeth 1 along the circumferential direction of the stator core is A, and the angle between the first slot 2 and the second slot 3 along the circumferential direction of the stator core is a1, 3≤a1 / A≤4.5. When the slot distribution is maintained, the cogging torque pk-pk value is the minimum. Figure 9 and Figure 10 As shown in the figure, the magnitude of the cogging torque is closely related to the Fourier variation coefficient of the permanent magnet remanence and the air gap magnetic permeance wave, and this coefficient is closely related to the magnetic pole structure, stator slot size, pole slot distribution, pole arc coefficient and cogging torque section. This limiting relationship can better achieve the pole slot matching of the stator and rotor on the basis of stator tooth slotting, thereby effectively reducing the cogging torque of the motor and reducing the motor torque pulsation and vibration noise.

[0037] In one embodiment, the minimum slot width of the first slot 2 and the second slot 3 is b2, the maximum slot width is b1, and 0.1≤b2 / b1≤0.9, thereby effectively limiting the slot shape and making the slot shape more optimized.

[0038] In one embodiment, the maximum slot width of the first slot 2 and the second slot 3 is b1, the slot width between two adjacent stator teeth 1 is B, and 0.5≤b1 / B≤0.75.

[0039] The size of the cogging torque is closely related to the Fourier variation coefficient of the permanent magnet remanence and the air gap magnetic permeance wave, and this coefficient is closely related to the magnetic pole structure, stator slot size, pole slot distribution, pole arc coefficient and cogging torque node. The size limit of the slot width is based on a certain width of the stator slot B, and the tooth slot width is selected within the optimal range.

[0040] In one embodiment, the inner circumference of each stator tooth 1 is provided with a first slot 2 and a second slot 3. In this embodiment, the structures on each stator tooth 1 are the same, so the structures of the first slot 2 and the second slot 3 on each stator tooth 1 are the same. In this embodiment, when forming the stator core, the silicon steel sheet can be cut into the rotor punching structure required by the stator core by wire cutting. On the premise of ensuring the coaxiality and roundness of the stator inner circle, n sections of complete stator core are fixed by welding or screws, where n = 1, 2, 3, 4..., and the n sections of core are spliced ​​into a complete stator core. The stator core can also be obtained by punching silicon steel sheets of fixed height using the core punching die of the present application.

[0041] In this embodiment, the stator core includes a first core punching sheet, which is provided with a first punching sheet slot. A portion of the first core punching sheets is stacked to form a first slot 2, and another portion of the first core punching sheets is flipped over and stacked to form a second slot 3. All the core punching sheets are stacked together and fixedly connected.

[0042] In this embodiment, the silicon steel sheet is cut into Figure 6 The core punchings shown have the same slot position for each tooth of the stator core, and all are single slots. On the basis of ensuring the coaxiality and roundness of the inner circle of the stator, n sections of stator core are fixed by welding or screws. The first surface of one section of the stator core is placed opposite the second surface of the stator core at the other end, and the offset slot structure in the above embodiment can be formed. The n-section core structure of the stator core does not require each section to have a slot structure, but the positions of the grooves opened on the same stator tooth 1 of the two stator cores with slot structures are not limited to be symmetrical about the center line of the stator tooth, and the angle a1 between the center lines of the two slots is 3 to 4.5 times A. The n sections of the two stator cores are spliced ​​into a complete stator core. In this embodiment, the structure of all the core punchings is consistent, and the above-mentioned offset slot structure is formed by changing the orientation of some of the core punchings. This structure can be formed using a single core punching, so the structure is simple and easy to implement, which can reduce processing costs and improve processing efficiency.

[0043] In one embodiment, the inner circumference of a portion of the stator teeth 1 is provided with a first slot 2 and a second slot 3 penetrating in the axial direction.

[0044] In one embodiment, the number of teeth of the stator tooth 1 is odd, and a third slot 4 is provided on one stator tooth 1 and passes through the stator core along the axial direction of the stator core. The third slot 4 is located on the center line of the stator tooth 1, and the stator teeth 1 on both sides of the stator tooth 1 are provided with a first slot 2 and a second slot 3. The stator teeth 1 on both sides of the stator tooth 1 are symmetrical about the center line of the stator tooth 1.

[0045] In this embodiment, the silicon steel sheet is cut into Figure 7 The stator punching shown is symmetrical about the stator center line of the stator tooth 1 with the groove located on the stator center line. The center line of the groove of the stator tooth 1 located on the center line coincides with the stator center line. Taking the tooth on the center line as the starting position, along the clockwise or counterclockwise direction, the angle between the center line of the groove on each tooth of a single stator punching and the center line of the tooth changes as the number of teeth increases. It is not limited to that the angle on each tooth must be different, but a1 must be 3 to 4.5 times A.

[0046] In one embodiment, the angle bisector between the first slot 2 and the second slot 3 coincides with the center line of the stator tooth 1 .

[0047] In one embodiment, the angle bisector between the first slot 2 and the second slot 3 is offset to one side relative to the center line of the stator tooth 1 .

[0048] In one embodiment, the inner circumferential surface of the stator tooth 1 is further provided with a fourth slot 5 , which is located in the axial middle of the stator core and between the first slot 2 and the second slot 3 along the circumferential direction.

[0049] In one embodiment, the stator core includes a first core punching sheet and a second core punching sheet, the first core punching sheet is provided with a first punching sheet slot, a portion of the first core punching sheets are stacked to form a first slot 2, and another portion of the first core punching sheets are flipped and stacked to form a second slot 3, the second core punching sheet is provided with a first punching sheet slot and a second punching sheet slot, and the second core punching sheets are stacked to form a first slot 2 and a fourth slot 5.

[0050] See also Figure 8 As shown, after adopting the staggered slot structure of the embodiment of the present application, the PK-PK value of the cogging torque is reduced by 30% compared with the double-through slot solution in the related art, the cogging torque is effectively controlled, and the motor torque pulsation and vibration noise are greatly reduced.

[0051] According to an embodiment of the present application, the motor includes a stator core, which is the stator core described above.

[0052] According to an embodiment of the present application, the compressor includes a motor, which is the motor described above.

[0053] According to an embodiment of the present application, an air conditioner includes a motor, which is the above-mentioned motor.

[0054] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0055] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application. The above are merely preferred embodiments of the present application. It should be noted that those skilled in the art may make various improvements and variations without departing from the technical principles of the present application, and such improvements and variations shall also be considered within the scope of protection of the present application.

Claims

1. A stator core, characterized in that: The invention comprises a stator tooth (1), wherein the inner circumferential surface of at least part of the stator tooth (1) is provided with a first slot (2) and a second slot (3), the first slot (2) is located at the first end of the stator core, the second slot (3) is located at the second end of the stator core, the first slot (2) and the second slot (3) are staggered along the circumference of the stator core, and the sum of the axial heights of the first slot (2) and the second slot (3) is the axial height of the stator core; The included angle between adjacent side edges of two adjacent stator teeth (1) along the circumferential direction of the stator core is A, and the included angle between the first slot (2) and the second slot (3) along the circumferential direction of the stator core is a1, 3≤a1 / A≤4.5; The inner circumferential surface of the stator tooth (1) is further provided with a fourth slot (5), and the fourth slot (5) is located in the axial middle of the stator core and between the first slot (2) and the second slot (3) along the circumferential direction.

2. The stator core according to claim 1, characterized in that The minimum slot width of the first slot (2) and the second slot (3) is b2, the maximum slot width is b1, and 0.1≤b2 / b1≤0.

9.

3. The stator core according to claim 1, characterized in that The maximum slot width of the first slot (2) and the second slot (3) is b1, the slot width between two adjacent stator teeth (1) is B, and 0.5≤b1 / B≤0.

75.

4. The stator core according to claim 1, wherein: The inner circumferential surface of each stator tooth (1) is provided with the first slot (2) and the second slot (3).

5. The stator core according to claim 1, characterized in that The inner circumferential surface of a portion of the stator teeth (1) is provided with the first slot (2) and the second slot (3) penetrating in the axial direction.

6. The stator core according to claim 1, characterized in that The number of teeth of the stator teeth (1) is odd, one of the stator teeth (1) is provided with a third slot (4) penetrating the stator core in the axial direction of the stator core, the third slot (4) is located on the center line of the stator tooth (1), the stator teeth (1) located on both sides of the stator tooth (1) are provided with the first slot (2) and the second slot (3), and the stator teeth (1) located on both sides of the stator tooth (1) are symmetrical about the center line of the stator tooth (1).

7. The stator core according to claim 1, characterized in that The bisector of the angle between the first slot (2) and the second slot (3) coincides with the center line of the stator tooth (1) where they are located.

8. The stator core according to claim 1, characterized in that The angle bisector between the first slot (2) and the second slot (3) is offset to one side relative to the center line of the stator tooth (1) in which they are located.

9. The stator core according to claim 1, characterized in that The stator core comprises a first core punching sheet, wherein the first core punching sheet is provided with a first punching sheet slot, a portion of the first core punching sheets is stacked to form the first slot (2), and another portion of the first core punching sheets is flipped over and stacked to form a second slot (3), and all the core punching sheets are stacked together and fixedly connected.

10. The stator core according to claim 8, characterized in that The stator core comprises a first core punching sheet and a second core punching sheet, wherein the first core punching sheet is provided with a first punching sheet slot, a portion of the first core punching sheets is stacked to form the first slot (2), and another portion of the first core punching sheets is flipped over and stacked to form a second slot (3), and the second core punching sheet is provided with a first punching sheet slot and a second punching sheet slot, and the second core punching sheets are stacked to form the first slot (2) and the fourth slot (5).

11. A motor comprising a stator core, characterized in that: The stator core is the stator core according to any one of claims 1 to 10.

12. A compressor comprising a motor, characterized in that: The motor is the motor according to claim 11.

13. An air conditioner comprising a motor, characterized in that: The motor is the motor according to claim 11.

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