A pointed-tooth stator structure and a motor having the stator

Abstract

The present invention discloses a sharp-tooth stator structure and a motor having the stator. The features are as follows: it includes a stator body, on the inner circumference of the stator body, a plurality of stator tooth boots are evenly arranged, between adjacent stator tooth boots, there are stator slots, at both ends of the mouth of the stator slot, there are slot mouth shoulders, and from both sides of the end face of the slot mouth shoulder, slot mouth teeth extend outwards. The slot mouth teeth include a first cutting surface and a second cutting surface. One end of the first cutting surface and one end of the second cutting surface form an included angle α. The other end of the first cutting surface is connected to the side surface of the slot mouth shoulder of the stator tooth boot, and the other end of the second cutting surface is connected to the end face of the slot mouth shoulder. The slot mouth teeth between two adjacent stator slots are symmetrical along the radial center line of the stator tooth boot. The present invention optimizes the stator tooth boot to form a claw-shaped slot mouth tooth shape of the stator slot. On the premise of not affecting the fundamental wave amplitude of the air-gap magnetic density and ensuring the output torque, it increases the frequency of the tooth-slot torque ripple, reduces its amplitude, and further reduces the torque fluctuation.

Description

Technical Field

[0001] The present invention relates to the field of new oil pump motors, and particularly to a sharp-tooth stator structure and a motor having the stator. Background Art

[0002] With the strong promotion of new energy vehicles, new energy electric vehicles are becoming more and more popular. The market's demand for the performance of the power system of electric vehicles is continuously increasing. The main drive motor is the power output component of the power system and is one of the most core components of electric vehicles. The performance indicators of the main drive motor are also getting higher and higher, such as high power density and torque density, small volume and light weight. However, with the improvement of power density, its heat dissipation problem has become more and more prominent. The currently commonly used heat dissipation solutions are water cooling and oil cooling. The oil cooling solution can directly cool the heat source to improve the cooling efficiency. Therefore, oil-cooled electric drives have become the development trend of new energy power systems. And the oil pump motor in the oil cooling solution has become a key step in circulating heat dissipation, which directly affects the performance advantages of the main drive motor. Currently, the main problems of oil pump motors are as follows: large torque fluctuations of the motor cause cycloid gears to knock, resulting in large broadband background noise; large cogging torque of the motor causes large torque fluctuations; large electromagnetic radial force of the motor causes poor NVH of the oil pump. Summary of the Invention

[0003] The present invention is to overcome the problems of large torque fluctuations and large electromagnetic radial magnetic force in the existing oil pump motors, which cause fluctuations and noise in the oil pump motors, and provides a sharp-tooth stator structure of an oil pump motor with high output torque and low cogging torque to reduce fluctuations and noise, and a motor thereof.

[0004] To achieve the above object, the present invention adopts the following technical solutions: A sharp-tooth stator structure includes a stator body. A plurality of stator tooth shoes are evenly arranged on the inner circumference of the stator body. A stator slot is provided between adjacent stator tooth shoes. Slot shoulders are provided at both ends of the mouth of the stator slot. Tooth tips extend outward from both sides of the end face of the slot shoulder. By optimizing the stator structure, the structure combining the slot shoulder and the tooth tip can increase the frequency of the stator cogging torque pulsation and reduce its amplitude without affecting the fundamental wave amplitude of the air-gap magnetic density and ensuring the output torque, and further reduce the torque fluctuation.

[0005] Preferably, the tooth tip includes a first cutting surface and a second cutting surface. An angle α is formed between one end of the first cutting surface and one end of the second cutting surface. The other end of the first cutting surface is connected to the side surface of the slot shoulder of the stator tooth shoe, and the other end of the second cutting surface is connected to the end face of the slot shoulder. The slot shoulder and the tooth tip on the stator tooth form a sharp-tooth claw-shaped stator tooth shoe shape, which effectively reduces the magnetic resistance and reduces the overall vibration and noise of the motor using the stator.

[0006] Preferably, the notch shoulders on both sides of the stator slots are symmetric about the radial center line of the stator slots, and the slot teeth between two adjacent stator slots are symmetric about the radial center line of the stator tooth shoes. The motor using this stator rotates stably, ensuring that the output speed of the motor is consistent.

[0007] Preferably, the ends of all the slot teeth inside the stator fall on the inscribed circle. The inscribed circle intersects the end face of the notch shoulder at two intersection points. The section formed by the two intersection points and the other end of the nearest second section forms a third section, and the length of the third section is c. Without affecting the fundamental wave amplitude of the air-gap magnetic density and ensuring the output torque, the slot teeth of the stator improve the frequency of the cogging torque ripple, reduce its amplitude, and further reduce the torque fluctuation.

[0008] Preferably, the length of the first section extending from the side face of the notch shoulder of the stator tooth shoe is d, and the linear distance of the included angle α from the end face of the notch shoulder is b.

[0009] Preferably, the first section is a plane or a curved surface, the second section is a plane or a curved surface, and the dimensions of the stator tooth shoe satisfy the relationship: 0.5 < b / d < 1, 3 < c / d < 7, 20° < α < 50°.

[0010] A motor with a sharp-tooth-shaped stator structure includes a rotor core. The outer periphery of the core is a cylindrical surface. The inner periphery of the core is provided with a plurality of axially penetrating magnetic steel slots at circumferential intervals. Each magnetic steel slot is provided with a magnetic steel. The magnetic steel is an S-pole magnetic steel or an N-pole magnetic steel, and the S-pole magnetic steels and the N-pole magnetic steels are arranged alternately at circumferential intervals along the core, providing a motor structure with high output torque and low cogging torque to reduce fluctuations.

[0011] Preferably, the magnetic steel is in a shape of a straight bar. If the thickness of the magnetic steel is h and the width is w, then h and w satisfy the following relationship: 1.5 mm < h < 2.2 mm, 10 mm < w < 16 mm; if h < 1.5 mm and w < 10 mm, the output torque of the motor is small and the performance is poor; if h > 2.2 mm and w > 16 mm, it will affect the very low material utilization rate of the permanent magnet and increase the cost of the motor.

[0012] Preferably, through holes are provided in the side steel slots. The through holes penetrate axially along the core, and the through holes are symmetric about the axial center line of the magnetic steel at both ends of the magnetic steel.

[0013] Therefore, the present invention has the following beneficial effects: The present invention optimizes the stator tooth shoe to form a claw-shaped stator slot tooth shape, and the slot teeth are symmetric about the radial center line of the stator tooth shoe. Without affecting the fundamental wave amplitude of the air-gap magnetic density and ensuring the output torque, the frequency of the cogging torque ripple is increased, its amplitude is reduced, and the torque fluctuation is further reduced. Description of the Drawings

[0014] Figure 1 It is a schematic cross-sectional structure diagram of the motor according to an embodiment of the present invention.

[0015] Figure 2 It is a schematic cross-sectional view of the stator and an enlarged view I of the stator tooth boot according to an embodiment of the present invention.

[0016] Figure 3 It is a schematic cross-sectional view of the rotor according to an embodiment of the present invention.

[0017] Figure 4 It is a comparison diagram of the electromagnetic force between the prior art and the present application according to an embodiment of the present invention.

[0018] Figure 5 It is a comparison diagram of the peak value of the cogging torque between the prior art and the present application according to an embodiment of the present invention.

[0019] Figure 6 It is a comparison diagram of the torque ripple between the prior art and the present application according to an embodiment of the present invention.

[0020] Figure 7 It is a schematic cross-sectional structure diagram of the motor of the prior art.

[0021] In the figure: 1, stator body; 2, stator tooth boot; 3, stator slot; 4, slot mouth shoulder; 5, slot mouth tooth; 6, first section plane; 7, second section plane; 8, included angle α; 9, third section plane; 10, through hole; 11, permanent magnet; 12, rotor; 13, inscribed circle. Specific embodiments

[0022] The following further describes the present invention in conjunction with the accompanying drawings and specific embodiments.

[0023] Embodiment:

[0024] Such as Figure 2 shown, a pointed-tooth-shaped stator structure, a stator body 1, on the inner circumference of the stator body 1, a plurality of stator tooth boots 2 are evenly arranged, a stator slot 3 is arranged between adjacent stator tooth boots 2, slot mouth shoulders 4 are arranged at both ends of the mouth of the stator slot 3, and slot mouth teeth 5 extend outward from both sides of the end face of the slot mouth shoulder 4. The slot mouth shoulders 4 on both sides of the stator slot 3 are symmetric about the radial center line of the stator slot 3, and the slot mouth teeth 5 between two adjacent stator slots 3 are symmetric about the radial center line of the stator tooth boot 2.

[0025] The slot tooth 5 includes a first cutting surface 6 and a second cutting surface 7. One end of the first cutting surface 6 forms an angle α8 with one end of the second cutting surface 7. The other end of the first cutting surface 6 is connected to the side surface of the slot shoulder 4 of the stator tooth shoe 2, and the other end of the second cutting surface 7 is connected to the end surface of the slot shoulder 4. The ends of the angle α8 of the slot tooth 5 all fall on the inscribed circle 13. The inscribed circle 13 intersects the end surface of the slot shoulder 4 at two intersection points. The cutting surface between the two intersection points and the other end of the nearest second cutting surface 7 forms a third cutting surface 9. The length of the third cutting surface 9 is c. The length of the first cutting surface 6 extending from the side surface of the slot shoulder 4 of the stator tooth shoe 2 is d, and the linear distance from the angle α8 to the end surface of the slot shoulder 4 is b. The first cutting surface 6 is a plane or a curved surface, the second cutting surface 7 is a plane or a curved surface, and the dimensions of the stator tooth shoe 2 satisfy the relationship: 0.5 < b / d < 1, 3 < c / d < 7, 20 degrees < α < 50 degrees.

[0026] The present invention also discloses a motor adopting a sharp-tooth stator structure. The motor is a 9-slot 6-pole motor. As Figure 1 , Figure 3 shown, it includes a rotor 12 iron core. The outer periphery of the iron core is a cylindrical surface. The outer peripheral surface of the iron core is a cylindrical surface. Six axially through magnetic steel slots are circumferentially spaced apart on the inner periphery of the iron core. A magnetic steel 11 is arranged in each magnetic steel slot. The magnetic steel 11 is an S-pole magnetic steel 11 or an N-pole magnetic steel 11, and the S-pole magnetic steel 11 and the N-pole magnetic steel 11 are arranged alternately at intervals along the circumference of the iron core. The magnetic steel 11 is in a straight shape. The thickness of the magnetic steel 11 is h, and the width is w. Then h and w satisfy the following relationship: 1.5 mm < h < 2.2 mm, 10 mm < w < 16 mm; if h < 1.5 mm and w < 10 mm, the output torque of the motor is small and the performance is poor; if h > 2.2 mm and w > 16 mm, it will affect the very low material utilization rate of the permanent magnet and increase the cost of the motor. A through hole 10 is arranged in the magnetic steel slot. The through hole 10 axially penetrates the iron core. The through hole 10 is symmetrically located at both ends of the magnetic steel along the axial center line of the magnetic steel.

[0027] As Figures 4 to 6 shown, compared with the motor of the closest prior art Figure 7 in the motor of the present invention, on the premise that the output torque of the motor structure is not reduced, the electromagnetic force is optimized by up to 30.7%, the torque ripple of the motor is reduced, the rated condition is reduced from 13.4% to 9.4%, and the peak value of the cogging torque is reduced by 80.9%.

[0028] Therefore, the optimized stator structure adopted by the present invention combines the slot shoulder 4 and the slot tooth 5 to increase the frequency of the stator cogging torque ripple and reduce its amplitude on the premise of not affecting the fundamental wave amplitude of the air-gap magnetic density and ensuring the output torque, and further reduce the torque fluctuation.

[0029] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art to which the present invention pertains may make various modifications or supplements to the described specific embodiments or use similar means for substitution, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0030] Although terms such as rotor, stator, stator tooth shoe, stator slot, slot mouth shoulder, etc. are used more frequently herein, the possibility of using other terms is not excluded. The use of these terms is only for more conveniently describing and explaining the essence of the present invention; interpreting them as any additional limitation is contrary to the spirit of the present invention.

Claims

1. A pointed-tooth stator structure, characterized in that, it includes a stator body, and a number of stator tooth boots are evenly arranged on the inner circumference of the stator body. There are stator slots between adjacent stator tooth boots. There are slot shoulders at both ends of the stator slot opening. Slot teeth extend outward from both sides of the end face of the slot shoulder; The slot teeth include a first cutting surface and a second cutting surface. An included angle a is formed between one end of the first cutting surface and one end of the second cutting surface; the length of the first cutting surface extending from the side surface of the slot shoulder of the stator tooth boot is d, and the linear distance from the included angle a to the end face of the slot shoulder is b; the ends of all the slot teeth inside the stator fall on the inscribed circle. The inscribed circle intersects the end face of the slot shoulder at two intersection points. The cutting surface formed between the two intersection points and the other end of the nearest second cutting surface forms a third cutting surface, and the length of the third cutting surface is c; The dimensions of the stator tooth boot satisfy the relationship: 20 degrees < a < 50 degrees, 0.5 < b / d < 1, 3 < c / d < 7.

2. A pointed-tooth stator structure according to claim 1, characterized in that, the other end of the first cutting surface is connected to the side surface of the slot shoulder of the stator tooth boot, and the other end of the second cutting surface is connected to the end face of the slot shoulder.

3. A pointed-tooth stator structure according to claim 2, characterized in that, the slot shoulders on both sides of the stator slot are symmetrical about the radial center line of the stator slot, and the slot teeth between two adjacent stator slots are symmetrical about the radial center line of the stator tooth boot.

4. A pointed-tooth stator structure according to claim 3, characterized in that, the first cutting surface is a plane or a curved surface, and the second cutting surface is a plane or a curved surface.

5. A motor with a pointed-tooth stator structure, including a rotor core. The outer peripheral surface of the core is a cylindrical surface. A number of axially penetrating magnetic steel slots are circumferentially spaced inside the core. A magnetic steel is arranged in each magnetic steel slot. The magnetic steel is an S-pole magnetic steel or an N-pole magnetic steel, and the S-pole magnetic steels and the N-pole magnetic steels are arranged alternately at intervals along the circumference of the core, characterized in that, the stator adopts the pointed-tooth stator structure described in any one of claims 1-4.

6. A motor with a pointed-tooth stator structure according to claim 5, characterized in that, the magnetic steel is in a straight shape.

7. A motor with a pointed-tooth stator structure according to claim 6, characterized in that, through holes are provided in the magnetic steel slots, and the through holes penetrate axially along the core.

8. A motor with a pointed-tooth stator structure according to claim 7, characterized in that, the through holes are symmetrical about the axial center line of the magnetic steel at both ends of the magnetic steel.

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