A claw-shaped stator and motor thereof

Abstract

The invention discloses a claw-shaped stator and a motor thereof; the stator tooth shoe is optimized to form a claw-shaped stator tooth shoe shape which is symmetrical about the tooth neutral line; under the premise of not affecting the fundamental wave amplitude of the air gap magnetic density and ensuring the output torque, the frequency of the tooth slot torque pulsation is increased, the amplitude is reduced, and the torque fluctuation is further reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a claw-shaped stator and a motor thereof. Background Art

[0002] With the vigorous promotion of new energy vehicles, new energy electric vehicles are becoming more and more popular, and the market demand for the performance of electric vehicle power systems is constantly increasing. The main drive motor is the power output component of the power system and one of the most core components of electric vehicles. The performance index requirements of the main drive motor are also getting higher and higher, such as high power density and torque density, small size and light weight. However, with the increase in power density, its heat dissipation problem is becoming more and more prominent. Currently, the 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, so oil-cooled electric drive has become the development trend of new energy power systems. The oil pump motor in the oil cooling solution becomes a key step in circulating heat dissipation, which directly affects the performance advantages of the main drive motor.

[0003] At present, the main problems of oil pump motors are as follows: large fluctuations in motor torque cause cycloid gear knocking, resulting in large broadband background noise; large motor tooth torque causes large torque fluctuations; large electromagnetic radial force of the motor causes poor NVH of the oil pump.

[0004] For example, a "new type of external rotor motor installation structure" disclosed in Chinese patent documents, with the announcement number CN207339443U, includes a motor stator and a motor rotor. The motor stator is provided with an L-shaped installation groove from the circumferential surface to the end surface. The number of the installation grooves is multiple and evenly distributed around the center of the motor stator. An L-shaped coil winding is arranged in the installation groove, and the two ends of the coil winding extend to the outside of the motor stator respectively. The motor rotor is matched and connected with the motor stator, and permanent magnets are arranged on the end and inner wall of the motor rotor. This utility can adopt an external rotor structure so that the stator slot faces outward, which is conducive to the integral embedding of the formed bent coil into the slot, which can greatly save the time of embedding wire, improve the torque density of the motor, and improve the utilization rate of the motor rotor core under the premise of ensuring mechanical strength. However, there are still problems such as large motor torque fluctuation causing cycloid gear knocking resulting in large broadband background noise; large electromagnetic radial force of the motor causing poor NVH of the oil pump. Summary of the invention

[0005] In view of the above problems, a claw-shaped stator and a motor thereof are proposed; the stator tooth shoe is optimized to form a claw-shaped stator tooth shoe shape, which is symmetrical about the tooth neutral line; without affecting the fundamental amplitude of the air gap magnetic density and ensuring the output torque, the frequency of the tooth slot torque pulsation is increased, its amplitude is reduced, and the torque fluctuation is further reduced.

[0006] The above technical problems of the present invention are mainly solved by the following technical solutions:

[0007] A claw-shaped stator and its motor, including a stator and a rotor. The tooth shoe of the stator includes four cutting edges. The first cutting edge is obliquely cut with the slot shoulder of the stator. The first cutting edge is obliquely cut with the second cutting edge. The extension line of the second cutting edge is obliquely cut with the neutral line of the stator tooth; the first cutting edge and the fourth cutting edge are symmetric about the tooth neutral line, and the second cutting edge and the third cutting edge are symmetric about the tooth neutral line; the first end point of the first cutting edge is set on the slot shoulder of the stator and is not on the inner diameter circle of the stator; the four cutting edges together form a claw-shaped stator tooth shoe. On the premise of not 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 ripple is further reduced.

[0008] Preferably, the rotor is a surface-mounted structure with an injection-molded magnetic ring as the permanent magnet; the inner diameter of the injection-molded permanent magnet is R1 and the outer diameter is R2. The conditions satisfied by the inner diameter R1 and the outer diameter R2 are: 1.5 < R2 - R1 < 6, with the unit of millimeter. If R2 - R1 < 1.5 mm, the output torque of the motor is small and the performance is poor; if R2 - R1 > 6 mm, it will affect the split ratio of the motor and cause an imbalance in the distribution ratio of copper loss and iron loss of the motor.

[0009] Preferably, the cutting depth of the first cutting edge on the tooth shoe is e, the cutting length of the second cutting edge on the tooth shoe is m, and the height of the slot shoulder is f. The conditions satisfied by the cutting length m and the cutting depth e are: 0 < e < f / 2. The conditions satisfied by the height of the slot shoulder f and the cutting length m are: 0 < m < f. If e < 0, the effect of optimizing the cogging torque and reducing the electromagnetic force of the motor cannot be achieved; if e > f / 2, it will affect the magnitude of the output torque of the motor and reduce the performance of the motor; the cutting length of the second cutting edge on the tooth shoe is m, and the relationship between m and f conforms to: 0 < m < f, otherwise, a good optimization effect cannot be achieved either.

[0010] Preferably, the included angle between the first cutting edge and the slot shoulder of the stator is set as a, and the included angle between the first cutting edge and the second cutting edge is set as b. The conditions satisfied by the included angle a and the included angle b are: 150° < a + b < 220°; if the included angle is too small, the cogging torque cannot be optimized; when the included angle is too large, it will affect the magnitude of the output torque of the motor and reduce the performance of the motor.

[0011] Preferably, the included angle between the extension line of the second cutting edge and the tooth neutral line is set as c. The condition satisfied by the included angle c is: 10° < c < 50°; if the included angle is too small, the cogging torque cannot be optimized; when the included angle is too large, it will affect the magnitude of the output torque of the motor and reduce the performance of the motor.

[0012] Preferably, the motor is a 9-slot 6-pole motor, which can maximize the improvement of the torque ripple frequency of the motor.

[0013] Preferably, the motor includes a cooling valve; the top of the cooling valve is arc-shaped, and a plurality of ventilation holes are arranged on the top of the cooling valve housing; a first filter is arranged inside the ventilation hole. The cooling valve includes a bottom plate, and a connecting port is arranged on the bottom plate; a second filter is arranged at the connecting port. The gear oil exchanges heat with the cooling valve, and the temperature quickly drops and condenses from an atomized state to a liquid state, and then returns to the bearing box along the conduit again, so as to realize the recovery of the gear oil. On the other hand, since the cooling valve is located downstream of the air supply port of the fan, and the cooling valve and the conduit have a basically complete shape except for the vents, the air supply of the fan can not only accelerate the condensation of the gear oil, but also avoid the splashing of the gear oil, thereby improving the recovery efficiency of the gear oil and avoiding pollution.

[0014] The beneficial effects of the present invention are:

[0015] The stator tooth shoe is optimized to form a claw-shaped stator tooth shoe shape that is symmetrical about the tooth neutral line; without affecting the fundamental amplitude of the air gap magnetic density and ensuring the output torque, the frequency of the tooth slot torque pulsation is increased, its amplitude is reduced, and the torque fluctuation is further reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a two-dimensional diagram of the motor of the present invention;

[0017] Figure 2 It is a stator punching diagram of the present invention;

[0018] Figure 3 It is a rotor punching diagram of the present invention;

[0019] Figure 4 Ventilation valve structure diagram;

[0020] Figure 5 It is a schematic diagram of the structure of the cooling valve in the ventilation valve;

[0021] Figure 6 This is a comparison diagram of the cogging torque of the motor of the present invention and the prior art;

[0022] Figure 7 This is a comparison diagram of the torque fluctuation of the motor of the present invention and the existing motor;

[0023] Figure 8 This is a comparison diagram of the electromagnetic force of the motor of the present invention and the existing motor. DETAILED DESCRIPTION

[0024] It should be understood that the embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope limited by the appended claims of the application.

[0025] The technical solution of the present invention will be further specifically described below through embodiments in conjunction with the accompanying drawings.

[0026] For the motor structure of this patent embodiment, a surface-mounted structure with an injection-molded magnetic ring is adopted for the rotor, and the stator tooth shoe is optimized to form a claw-shaped stator tooth shoe shape that is symmetric about the tooth neutral line. The optimized structure is to increase the frequency of the 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, thereby further reducing the torque fluctuation. The included angle between the first cutting edge and the stator slot shoulder is a, the included angle between the first cutting edge and the second cutting edge is b, and the included angle between the second cutting edge and the tooth neutral line is c. The relationship satisfied among a, b, and c is: 150° < a + b < 220°, 10° < c < 50°; if a + b < 150° and c < 10°, the effect of optimizing the cogging torque cannot be achieved; if a + b > 220° and c > 50°, the magnitude of the motor output torque will be affected and the motor performance will be reduced; the cutting depth of the first cutting edge on the tooth shoe is e, and the slot shoulder height is f. The relationship between e and f is: 0 < e < f / 2; if e < 0, the effect of optimizing the cogging torque and reducing the motor electromagnetic force cannot be achieved; if e > f / 2, the magnitude of the motor output torque will be affected and the motor performance will be reduced; the cutting length of the second cutting edge on the tooth shoe is m, and the relationship between m and f is: 0 < m < f, otherwise, a good optimization effect cannot be achieved either. The inner diameter of the injection-molded permanent magnet is R1, and the outer diameter is R2. The relationship between R1 and R2 is: 1.5 mm < R2 - R1 < 6 mm; if R2 - R1 < 1.5 mm, the motor output torque is small and the performance is poor; if R2 - R1 > 6 mm, the magnitude of the motor split ratio will be affected, resulting in an imbalance in the distribution ratio of copper loss and iron loss of the motor.

[0027] The motor structure of this embodiment optimizes 20% of the electromagnetic force without reducing the output torque, reduces the motor torque ripple, and the rated condition drops from 21.4% to 9.8%, reducing the cogging torque by 72.3%.

Claims

1. A motor, comprising a stator and a rotor, characterized in that: The tooth shoe of the stator includes four cutting edges, the first cutting edge is beveled with the notch shoulder of the stator, the first cutting edge is beveled with the second cutting edge, and the extension line of the second cutting edge is beveled with the neutral line of the stator tooth; the first cutting edge and the fourth cutting edge are symmetrical along the neutral line of the tooth, and the second cutting edge and the third cutting edge are symmetrical along the neutral line of the tooth; the first end point of the first cutting edge is set on the notch shoulder of the stator and is not on the inner diameter circle of the stator; the fifth cutting edge is connected between the second cutting edge and the third cutting edge, and the five cutting edges together form a claw-shaped stator tooth shoe; The rotor is a magnetic steel, which is a surface-mounted structure of an injection-molded magnetic ring. The difference between the outer diameter and the inner diameter of the magnetic steel is greater than 1.5 mm and less than 6 mm. The cutting depth of the first cutting edge on the tooth shoe is greater than 0 and less than 1 / 2 of the notch shoulder height. The cutting length of the second cutting edge on the tooth shoe is greater than 0 and less than the notch shoulder height. The sum of the angle between the stator slot shoulder and the first cut edge and the angle between the second cut edge and the first cut edge is greater than 150° and less than 220°; The included angle between the extension line of the second cutting edge and the tooth neutral line is greater than 10° and less than 50°.

2. A motor according to claim 1, characterized in that: The motor uses a 9-slot 6-pole motor.

3. A motor as claimed in claim 2, characterized in that: The motor comprises a cooling valve; the top of the cooling valve is arc-shaped, and a plurality of ventilation holes are arranged on the top of the cooling valve box.

4. A motor as claimed in claim 3, characterized in that: The cooling valve comprises a bottom, the bottom is arc-shaped, a bottom communication port is arranged above the bottom, and a second filter screen is arranged at the bottom communication port.

5. A motor as claimed in claim 4, characterized in that: A first filter screen is arranged inside the ventilation hole; and the bottom connecting port of the motor cooling valve is connected to the motor oil valve through a conduit for cooling the oil and gas.

6. A motor as claimed in claim 5, characterized in that: The cooling valve is provided with a first condensation plate and a second condensation plate, wherein the first condensation plate is arranged close to the arc top; the second condensation plate is arranged close to the arc bottom; a plurality of drainage holes are respectively provided on the first condensation plate and the second condensation plate; the first filter net and the second filter net use air filter cotton.

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