Motor stator assembly, motor

Abstract

The application provides a motor stator assembly and a motor, and belongs to the field of motor design.The motor stator assembly comprises a stator core, the stator core comprises a yoke ring and a plurality of stator teeth, adjacent stator teeth form stator slots, and the motor stator assembly further comprises a stator slot spacing assembly, the stator slot spacing assembly comprises a plurality of magnetic conductive strips, each magnetic conductive strip is located in a slot opening of a stator slot, and a gap is formed between the magnetic conductive strip and the adjacent stator teeth.The application sets one magnetic conductive strip in the slot opening of each stator slot, thereby increasing the number of stator slot slots to twice the original number, greatly reducing the cogging torque and harmonics under the operating condition of the motor, greatly reducing the actual slot width of the stator slot, and optimizing the noise and vibration during the operation of the motor.Different from the traditional subtractive method for reducing the cogging harmonics, the application increases the number of stator teeth in a single period by additive manufacturing to reduce the cogging harmonics, and has the advantage of not damaging the magnetic flux path of the stator teeth.

Description

Technical Field

[0001] This invention belongs to the field of motor design technology, specifically relating to a motor stator assembly and a motor. Background Technology

[0002] With the rapid development of permanent magnet brushless DC motors, the requirements for motor development have gone beyond simply meeting performance and functional design requirements. In the course of industry development, low noise and low vibration are another direction for motor development.

[0003] Currently, common methods for reducing noise in the market include vector control boards, vibration-damping rotors, and stator optimization. Stator optimization often involves improving the slot-pole relationship of the stator core to reduce cogging torque and no-load harmonics, thereby reducing noise and vibration. Based on the goal of reducing cogging torque and harmonics to lower noise and motor vibration, this invention is proposed. Summary of the Invention

[0004] Therefore, the present invention provides a motor stator assembly and a motor, which can solve the technical problem in the prior art that the cogging torque and harmonics of the motor stator core are large, resulting in large noise and vibration during motor operation.

[0005] To address the aforementioned problems, the present invention provides a motor stator assembly, comprising a stator core, wherein the stator core includes a yoke ring and a plurality of stator teeth located radially inside the yoke ring, wherein stator slots are formed between adjacent stator teeth, and further comprising a stator slot spacing assembly, wherein the stator slot spacing assembly includes a plurality of magnetic strips, each magnetic strip being located within the slot opening of the stator slot, and a gap being formed between the magnetic strips and the adjacent stator teeth.

[0006] In some embodiments, projected onto any radial plane of the stator core, the stator slot has a line of symmetry in the radial direction of the stator core, and the magnetic strip is symmetrical about the line of symmetry of the corresponding stator slot.

[0007] In some embodiments, the cross-section of the magnetic strip is a regular polygon; and / or, the magnetic strip has a radially inner surface facing the axis of the stator core, the radius of which is equal to the inner radius of the stator tooth.

[0008] In some embodiments, the cross-section of the magnetic strip is a regular hexagon.

[0009] In some embodiments, the minimum distance between the magnetic stripe and the adjacent stator tooth is c, where c ≥ 0.2 mm.

[0010] In some embodiments, the stator slot spacing assembly further includes a first end ring, the first ends of the plurality of magnetic strips being connected to the first axial end face of the first end ring, and the first axial end face of the first end ring being able to connect with the first end face of the stator core.

[0011] In some embodiments, the stator slot spacing assembly further includes a second end ring, the second ends of the plurality of magnetic strips being connected to the first axial end face of the second end ring, and the first axial end face of the second end ring being able to connect with the second end face of the stator core.

[0012] In some embodiments, the first end face and the second end face of the stator core are both provided with an insulating frame, and the first end ring and / or the second end ring are inserted into the corresponding insulating frame.

[0013] In some embodiments, the first end ring and / or the second end ring are inserted into the magnetic strip.

[0014] The present invention also provides an electric motor, including the above-described motor stator assembly.

[0015] This invention provides a motor stator assembly and a motor. By setting a magnetic strip in the slot opening of each stator slot, the number of stator slots can be doubled. This greatly reduces cogging torque and harmonics during motor operation, and the actual slot width is significantly reduced, thereby optimizing noise and vibration during motor operation. Unlike traditional subtractive material reduction of cogging harmonics (i.e., by creating virtual slots in the stator core teeth), this invention reduces cogging harmonics by increasing the number of slots in a single cycle of the stator through additive material, which has the advantage of not disrupting the magnetic field lines of the stator teeth. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural diagram of the motor stator assembly according to an embodiment of the present invention;

[0017] Figure 2 for Figure 1 The front view;

[0018] Figure 3 for Figure 1 A cross-sectional schematic diagram of the motor stator assembly;

[0019] Figure 4 for Figure 3 A magnified view of a section at point A in the middle;

[0020] Figure 5 for Figure 1 A three-dimensional structural diagram of the stator slot spacing assembly;

[0021] Figure 6 for Figure 5 Partial structural disassembly diagram;

[0022] Figure 7 for Figure 1 A partial structural diagram of the insulating skeleton in the diagram;

[0023] Figure 8 The figure shows the no-load harmonic simulation during the operation of a motor stator that does not use the stator slot spacing component of the present invention. The horizontal axis of the figure is the frequency (Hz) and the vertical axis is the harmonic power (W).

[0024] Figure 9 The figure shows the no-load harmonic simulation during the operation of the stator of a motor using the stator slot spacing assembly of the present invention. The horizontal axis of the figure is the frequency (Hz) and the vertical axis is the harmonic power (W).

[0025] Figure 10 A simulation diagram comparing the cogging torque of the motor stator before and after using the stator slot spacing assembly of the present invention during operation.

[0026] Figure 11 This is a simulation diagram of the local magnetic field lines of a motor stator core that does not employ the stator slot spacing assembly of the present invention in the prior art;

[0027] Figure 12 This is a simulation diagram of the local magnetic field lines of the stator core of a motor using the stator slot spacing assembly of the present invention.

[0028] The reference numerals in the attached figures are as follows:

[0029] 1. Stator core; 11. Yoke ring; 12. Stator tooth; 13. Stator slot; 131. Slot opening; 2. Stator slot spacer assembly; 21. Magnetic strip; 22. First end ring; 23. Second end ring; 24. First insertion hole; 25. Second insertion hole; 3. Insulating frame; 31. Insertion structure. Detailed Implementation

[0030] See also Figures 1 to 12As shown, according to an embodiment of the present invention, a motor stator assembly is provided, including a stator core 1. The stator core 1 includes a yoke ring 11 and a plurality of stator teeth 12 located radially inside the yoke ring 11. Stator slots 13 are formed between adjacent stator teeth 12. The assembly also includes a stator slot spacing assembly 2, which includes a plurality of magnetic strips 21. Each magnetic strip 21 is located within the slot opening 131 of the stator slot 13. There is a gap between the magnetic strip 21 and the adjacent stator teeth 12. It is understood that the aforementioned gap refers to the magnetic strip 21 not contacting the stator teeth 12. The aforementioned magnetic strip 21 is specifically, for example, an iron strip, a column, or a rod. Of course, other magnetic materials can also be used. In this technical solution, a magnetic strip 21 is set in the slot opening 131 of each stator slot 13, thereby doubling the number of stator slots in the motor stator. This significantly reduces cogging torque and harmonics during motor operation, and the actual slot width of the stator slot 13 is greatly reduced, thus optimizing noise and vibration during motor operation. More importantly, unlike the traditional subtractive method for reducing cogging harmonics (i.e., by creating virtual slots in the stator core teeth), this invention reduces cogging harmonics by increasing the number of slots in a single cycle of the stator through additive manufacturing, which has the advantage of not disrupting the magnetic field lines of the stator teeth (see also...). Figure 11 and 12 As shown in the figure, it is understandable that the more uniform and gentle the magnetic field lines are, the less noise and vibration the motor will have.

[0031] It is understood that, assuming the motor stator assembly of the present invention has n slots and p poles, the aforementioned magnetic strips 21 will have n corresponding magnetic strips 21. The n magnetic strips 21 are respectively arranged in a one-to-one correspondence with the n stator slots 13. The number of slots of the stator slots 13 increases from n slots to 2n, and the number of cogging harmonics in a single cycle increases to twice the original number. Taking 12 slots as an example, if the motor has 12 slots, then the stator slot spacing assembly 2 has 12 magnetic strips 21, the number of slots changes from the original 12 to 24 slots, and the number of cogging harmonics becomes twice the original number.

[0032] In some embodiments, when projected onto any radial plane of the stator core 1, the stator slot 13 has a line of symmetry in the radial direction of the stator core 1, and the magnetic strip 21 is symmetrical about the line of symmetry of the corresponding stator slot 13. That is, the magnetic strip 21 is distributed at the center of the slot opening 131 of the adjacent stator slot 13, so that the tooth distribution is more uniform and the periodicity is stable.

[0033] In some embodiments, the cross-section of the magnetic strip 21 is a regular polygon, such as an equilateral triangle, a square, a regular pentagon, etc., preferably a regular hexagon. It is understood that since the magnetic field lines are curved, using a regular hexagon can significantly reduce material waste at the corners of triangles or quadrilaterals, and the hexagonal structure is more stable and easier to process. In another embodiment, the magnetic strip 21 has a radially inner side facing the axis of the stator core 1, and the radius of the radially inner side is equal to the inner radius of the stator tooth 12, which can make the air gap change approach a sinusoidal change.

[0034] In some embodiments, the minimum distance between the magnetic strip 21 and the adjacent stator tooth 12 is c, where c ≥ 0.2 mm. This prevents the magnetic lines of force from forming a closed loop within the stator core, thus preventing the rotor from being conductive. In other words, this minimum distance avoids the formation of a closed loop of magnetic lines of force within the stator core. See details. Figure 3 and Figure 4 As shown, the angle between two adjacent stator teeth 12, i.e., the stator teeth 12 at slot 131, is α° (α≤30°, not shown in the figure). The stator inner diameter is D. The distance between the two stator teeth is a=D*sin(α° / 2), which is the original stator slot width. The width of the magnetic strip 21 is b=a-2c. After forming the new stator assembly structure, the stator slot width is reduced from the original amm to cmm, the slot width is reduced to c / a, the number of stator slots is doubled, and the stator slot width is reduced to c / a times the original. This increases the cogging harmonic order, reduces the no-load harmonic, and reduces the cogging torque. The fifth no-load harmonic is reduced to 76% of the original (see also [reference]). Figure 8 and 9 The cogging torque is reduced to 56% of its original value (e.g., Figure 10 ).

[0035] See also Figure 5 and Figure 6 As shown, the stator slot spacing assembly 2 further includes a first end ring 22. The first ends of multiple magnetic strips 21 are connected to the first axial end face of the first end ring 22, and the first axial end face of the first end ring 22 can be connected to the first end face of the stator core 1. The first end ring 22 connects the magnetic strips 21 into a whole, and the first end ring 22 is fixedly connected to the stator core 1 for easy assembly. In another preferred embodiment, the stator slot spacing assembly 2 further includes a second end ring 23. The second ends of multiple magnetic strips 21 are connected to the first axial end face of the second end ring 23, and the first axial end face of the second end ring 23 can be connected to the second end face of the stator core 1. That is, the first end ring 22 and the second end ring 23 respectively form a reliable clamping of the two ends of the magnetic strips 21, and the three form a structure similar to a squirrel cage. The first end ring 22 and the second end ring 23 form a reliable connection for each magnetic strip 21, so that each magnetic strip 21 can be reliably placed in the slot 131.

[0036] The stator core 1 has an insulating frame 3 at both its first and second end faces. This insulating frame 3 can be integrally injection molded (i.e., plastic-coated) onto the stator core 1, and the first end ring 22 and / or the second end ring 23 are inserted into and connected to the corresponding insulating frame 3. Specifically, see [reference needed]. Figures 5 to 7 As shown, the insulating frame 3 has a protruding insertion structure 31 extending along its axial direction away from the stator core 1. This insertion structure 31 can specifically be a stepped insert. The corresponding first end ring 22 and second end ring 23, in addition to having a first insertion hole 24, also have a second insertion hole 25. Each insertion structure 31 is inserted into each of the second insertion holes 25, while the end of the magnetic strip 21 is inserted into each of the first insertion holes 24. That is, the first end ring 22 and / or the second end ring 23 are inserted into the magnetic strip 21. In a specific embodiment, after the first end ring 22 and the magnetic strip 21 are inserted into each other, they can be further encapsulated into a single unit.

[0037] The motor stator assembly of the present invention can be assembled in the following manner:

[0038] Step 1: Select the number of magnetic strips (specifically iron rods, the same below) in the stator slot spacing assembly based on the number of stator slots;

[0039] Step 2: Determine the height of the iron bar based on the stator core height and the frame height;

[0040] Step 3: Design wedge blocks (i.e., the first end ring and the second end ring mentioned above) that meet the assembly requirements according to the dimensions of the plastic-coated stator;

[0041] Step 4: Complete the stator assembly with plastic coating for integrated use.

[0042] According to an embodiment of the present invention, an electric motor is also provided, including the above-described motor stator assembly.

[0043] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0044] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above are merely preferred embodiments of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A motor stator assembly, characterized in that, The system includes a stator core (1), which includes a yoke ring (11) and a plurality of stator teeth (12) located radially inside the yoke ring (11), with stator slots (13) formed between adjacent stator teeth (12). It also includes a stator slot spacing assembly (2), which includes a plurality of magnetic strips (21), each magnetic strip (21) located within the slot opening (131) of the stator slot (13), with a gap between the magnetic strip (21) and the adjacent stator teeth (12). The stator slot spacing assembly (2) further includes a first end ring (22), with the first ends of the plurality of magnetic strips (21) connected to the first axial end face of the first end ring (22), and the first axial end face of the first end ring (22) being able to connect with the first end face of the stator core (1). The stator slot spacing assembly (2) also includes a second end ring (23). The second ends of the multiple magnetic strips (21) are connected to the first axial end face of the second end ring (23), and the first axial end face of the second end ring (23) can be connected to the second end face of the stator core (1); the first end face and the second end face of the stator core (1) are both provided with an insulating skeleton (3), and the first end ring (22) and / or the second end ring (23) are inserted into the corresponding insulating skeleton (3); the insulating skeleton (3) is provided with a protruding insertion structure (31) extending along its axial direction away from the stator core (1), and the corresponding first end ring (22) and second end ring (23) are provided with a second insertion hole (25), and each insertion structure (31) is inserted into each of the second insertion holes (25). The insulating skeleton (3) is formed on the stator core (1) by integral injection molding.

2. The motor stator assembly according to claim 1, characterized in that, Projected onto any radial plane of the stator core (1), the stator slot (13) has a line of symmetry in the radial direction of the stator core (1), and the magnetic strip (21) is symmetrical about the line of symmetry of the corresponding stator slot (13).

3. The motor stator assembly according to claim 2, characterized in that, The cross-section of the magnetic strip (21) is a regular polygon; and / or, the magnetic strip (21) has a radially inner side facing the axis of the stator core (1), the radius of which is equal to the inner radius of the stator tooth (12).

4. The motor stator assembly according to claim 3, characterized in that, The cross-section of the magnetic strip (21) is a regular hexagon.

5. The motor stator assembly according to claim 2, characterized in that, The minimum distance between the magnetic strip (21) and the adjacent stator tooth (12) is c, where c ≥ 0.2 mm.

6. The motor stator assembly according to claim 1, characterized in that, The first end ring (22) and / or the second end ring (23) are inserted into the magnetic strip (21).

7. An electric motor, characterized in that, Includes the motor stator assembly according to any one of claims 1 to 6.

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