CN114172283B

CN114172283B - Stator punching sheet, stator core, motor and vehicle

Info

Publication number: CN114172283B
Application number: CN202111488467.1A
Authority: CN
Inventors: 伍永树; 贾金信; 姜月明; 张琦; 唐志伟
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2021-12-07
Filing date: 2021-12-07
Publication date: 2023-03-14
Anticipated expiration: 2041-12-07
Also published as: CN114172283A

Abstract

The invention provides a stator punching sheet, a stator core, a motor and a vehicle, wherein the stator punching sheet comprises a yoke ring and a plurality of stator teeth connected to the yoke ring, each stator tooth comprises a tooth shoe, the projection of the tooth shoe on the radial surface of the stator punching sheet along the axial direction of the stator punching sheet is arranged, the shoe surface of the tooth shoe comprises a first circular arc section, a second circular arc section and a third circular arc section which are concentric with the circle center of the yoke ring, the radius of the first circular arc section is smaller than that of the second circular arc section, and the radius of the third circular arc section is larger than that of the second circular arc section. According to the invention, the stator and rotor air gap with larger radial thickness is provided, which is beneficial to reducing the density of radial electromagnetic force, thereby reducing the electromagnetic vibration and noise of the motor and weakening the cogging torque, and the stator and rotor air gap with smaller radial thickness is provided, which is beneficial to increasing the output torque of the motor.

Description

Stator punching sheet, stator core, motor and vehicle

Technical Field

The invention belongs to the technical field of motor manufacturing, and particularly relates to a stator punching sheet, a stator core, a motor and a vehicle.

Background

The built-in permanent magnet synchronous motor is an efficient and energy-saving alternating current motor, and is widely applied to the field of new energy automobiles due to the advantages of high efficiency, high power factor, high power density, high torque-current ratio and the like.

The built-in permanent magnet synchronous motor for the vehicle overcomes the defects of an alternating current asynchronous motor and a traditional synchronous motor, has a simpler control mode, but has a fatal defect which restricts the development of the built-in permanent magnet synchronous motor, namely electromagnetic vibration and noise. Designers of new energy automobile motors spend a great deal of effort in developing new products to optimize motor vibration and noise. The electromagnetic vibration of the permanent magnet synchronous motor is related to the electromagnetic parameters, the control mode and the mechanical structure parameters of the motor, and the most direct and effective mode for reducing the electromagnetic vibration and the noise of the motor is to increase the length of an air gap (namely the radial thickness of the air gap of a stator and a rotor), but the torque output of the motor is often reduced by the electromagnetic vibration and the noise of the motor.

Disclosure of Invention

Therefore, the invention provides a stator punching sheet, a stator core, a motor and a vehicle, which can overcome the defect that the torque output of the motor is reduced because the radial thickness of a stator and rotor air gap is singly increased in order to reduce the electromagnetic vibration and the noise of the motor in the related technology.

In order to solve the above problems, the present invention provides a stator punching sheet, including a yoke ring and a plurality of stator teeth connected to the yoke ring, where the stator teeth include tooth shoes, and a projection of the tooth shoes on a radial surface of the stator punching sheet along an axial direction of the stator punching sheet, and a shoe surface of the tooth shoes includes a first arc segment, a second arc segment, and a third arc segment concentric with a circle center of the yoke ring, where a radius of the first arc segment is smaller than a radius of the second arc segment, and a radius of the third arc segment is larger than a radius of the second arc segment.

In some embodiments, the radius of the first arc segment is R1, the radius of the second arc segment is R2, the radius of the third arc segment is R3, the reference set value of the stator-rotor air gap formed after the stator lamination and the corresponding motor rotor are assembled is X, the radius of the arc segment corresponding to the shoe surface corresponding to the stator-rotor air gap corresponding to X is R0, R0- (0.3-0.5) X is not less than R1 and not more than R0, and/or R0 is not less than R2 and not more than R2

(R0 + (0.3-0.5) X), and/or (R0 + (0.3-0.5) X) < R3 ≦ (R0 + (0.6-0.9) X).

In some embodiments, the first circular arc segment corresponds to a central angle α 1, the second circular arc segment corresponds to a central angle α 2, the boot surface corresponds to a

central angle α

0,0 < α 1 ≦ α 0/3, and α 0/3 ≦ α 2 ≦ 2 α 0/3.

In some embodiments, the third arc segment corresponds to a central angle α 3,0 < α 3 ≦ α 0/3.

In some embodiments, the second arc segment is between the first arc segment and the third arc segment.

In some embodiments, two adjacent end points of the first circular arc segment and the second circular arc segment are connected through a first straight line segment, and/or two adjacent end points of the second circular arc segment and the third circular arc segment are connected through a second straight line segment.

In some embodiments, the slope of the first straight line segment is equal to the slope of the second straight line segment.

The invention also provides a motor stator which is formed by laminating the stator punching sheets.

The invention also provides a motor which comprises the motor stator.

The invention further provides a vehicle comprising the motor.

Compared with the shoe surface of the arc section with single radius in the prior art, the stator punching sheet, the stator core, the motor and the vehicle provided by the invention have the advantages that the stator punching sheet, the stator core, the motor and the vehicle have the design of the first arc section, the second arc section and the third arc section with different radii, the stator and the rotor air gaps with larger radial thickness are provided, the radial electromagnetic force density is favorably reduced, the electromagnetic vibration and noise of the motor are reduced, the cogging torque is weakened, the stator and the rotor air gaps with smaller radial thickness are provided, and the output torque of the motor is favorably increased.

Drawings

Fig. 1 is a schematic structural diagram of a stator lamination according to an embodiment of the present invention, and shows a stator lamination of a 12-pole 72-slot synchronous motor;

FIG. 2 is a partial schematic view of the stator teeth of FIG. 1;

FIG. 3 is a simplified schematic diagram of the radial electromagnetic force of the stator teeth of FIG. 1;

fig. 4 shows the torque ripple simulation results of the stator lamination of the shoe surface formed by a single arc segment in the prior art and the stator lamination of the shoe surface of the present invention.

The reference numerals are represented as:

1. a yoke ring; 2. stator teeth; 31. a first arc segment; 32. a second arc segment; 33. a third arc segment; 34. a first straight line segment; 35. a second straight line segment; 4. a reference shoe surface.

Detailed Description

With reference to fig. 1 to 4, according to an embodiment of the present invention, a stator lamination is provided, which includes a yoke ring 1 and a plurality of stator teeth 2 connected to the yoke ring 1, where the stator teeth 2 include tooth shoes, and projections of the tooth shoes on a radial surface of the stator lamination along an axial direction of the stator lamination, and shoe surfaces of the tooth shoes include a first arc segment 31, a second arc segment 32, and a third arc segment 33 that are concentric with a center of a circle of the yoke ring 1, where a radius of the first arc segment 31 is smaller than a radius of the second arc segment 32, and a radius of the third arc segment 33 is larger than a radius of the second arc segment 32. Among this technical scheme, the radius is unequal first circular arc section 31, second circular arc section 32 and third circular arc section 33's design compares with the vamp of single radius circular arc section among the prior art, has both had the stator and rotor air gap of great radial thickness, does benefit to and reduces radial electromagnetic force density to reduce motor electromagnetic vibration and noise, weaken the tooth's socket torque, have the stator and rotor air gap of less radial thickness again, do benefit to the increase motor output torque.

It will be understood that at least the first circular arc segment 31 should have a radius smaller than the circular arc radius of the reference shoe surface 4, at least the third circular arc segment 33 has a radius larger than the circular arc radius of the reference shoe surface 4, and the second circular arc segment 32 may have a radius equal to or larger than the circular arc radius of the reference shoe surface 4. The reference shoe surface 4 is the improved basis of the technical scheme of the three-segment circular arc segment in the invention. When the radius of the second circular arc segment 32 is equal to the circular arc radius of the reference shoe surface 4, the effect of improving noise is slightly insufficient, but the output performance is improved.

In some embodiments, the radius of the first circular arc segment 31 is R1, the radius of the second circular arc segment 32 is R2, the radius of the third circular arc segment 33 is R3, the reference set value of the stator-rotor air gap formed after the stator lamination is assembled with the corresponding motor rotor is X, the radius of the circular arc segment corresponding to the shoe surface corresponding to the stator-rotor air gap corresponding to X is R0, R0- (0.3-0.5) X is not less than R1 and is less than R0, and/or R0 is not less than R2 is not less than (R0 + (0.3-0.5) X), and/or (R0 + (0.3-0.5) X) < R3 is not more than (R0 + (0.6-0.9) X. The reference set value X is a radial thickness of a stator-rotor air gap formed between the reference shoe surface 4 and the corresponding motor rotor, and the R0 is a radius of the reference shoe surface 4, and the unit of each value is usually mm. For a permanent magnet synchronous motor, the size of the air gap affects the output performance of the motor and the quality of electromagnetic vibration and noise. Generally, the smaller the air gap, the better the output, but electromagnetic vibrations and noise will also be very significant; meanwhile, if the air gap is too small, the chamber is easily swept. The prior art air gap in this example is 1mm (i.e., X =1 mm). In the invention, the value of R1 reduces the local air gap, and focuses on increasing the output torque of the motor; the values of R2 and R3 are equivalent to increase a local air gap, so that the torque pulsation can be reduced, the electromagnetic vibration is reduced, and the noise is improved. Because the radial thickness of the air gap between the stator and the rotor is increased, the magnetic conductance of the air gap is reduced, the harmonic magnetic flux density of the air gap can be reduced, the radial force generated by the interaction of any two harmonic magnetic fields is approximately inversely proportional to the quadratic power of the length of the air gap, and therefore, the radial thickness of the air gap is increased, and the electromagnetic noise can be reduced.

In some embodiments, the first circular arc segment 31 corresponds to a central angle α 1, the second circular arc segment 32 corresponds to a central angle α 2, the boot surface corresponds to a

central angle α

0,0 < α 1 ≦ α 0/3, α 0/3 ≦ α 2 ≦ 2 α 0/3, and further, the third circular arc segment 33 corresponds to a central angle α 3,0 < α 3 ≦ α 0/3. Therefore, the second arc segment 32 can be ensured to occupy a larger area, and the effect of reducing the torque pulsation is more obvious. Referring to fig. 4, under the condition that all simulation conditions and settings are the same, the technical solution of the present invention can reduce (4.28% -2.66%)/4.28% =37.9% of torque ripple, and the output torque is lost by only 1.3%.

In some embodiments, the second arc segment 32 is between the first arc segment 31 and the third arc segment 33. In a specific embodiment, two adjacent end points of the first circular arc segment 31 and the second circular arc segment 32 are connected by a first straight line segment 34, and/or two adjacent end points of the second circular arc segment 32 and the third circular arc segment 33 are connected by a second straight line segment 35, and a slope of the first straight line segment 34 is equal to a slope of the second straight line segment 35. The design can avoid the phenomenon of supersaturation of magnetic density, and the output torque of the motor can not reach the designed result after given current appears.

Fig. 3 is a schematic sketch of the radial electromagnetic force of the stator teeth of the stator punching sheet of the invention, wherein F is the radial electromagnetic force synthesized under the condition of a rotor monopole, fr is the electromagnetic force formed near a single stator tooth where a winding is located in the prior art, and the magnitude of the final air gap radial electromagnetic force is F-Fr & gt 0. F1, F2 and F3 are respectively radial electromagnetic forces corresponding to the vicinity of the 3-segment circular arc in the present invention, F1+ F2+ F3= Fr, fa and Fb are electromagnetic forces in the vicinity of the two-segment transition straight line, which respectively generate radial and tangential components, which contribute to the rotation of the rotor. Therefore, the air gap radial electromagnetic force is F- (F1 + F2+ F3) -Fa radial-Fb radial larger than 0, and compared with the prior art, the radial electromagnetic force is reduced, which is beneficial to weakening electromagnetic vibration and reducing motor noise.

According to the embodiment of the invention, the motor stator is formed by laminating the stator punching sheets.

According to an embodiment of the present invention, there is also provided a motor, in particular a permanent magnet synchronous motor, including the above-described motor stator.

According to an embodiment of the invention, a vehicle, in particular a bus vehicle, is also provided, comprising the above-mentioned electric machine.

It is readily understood by a person skilled in the art that the advantageous ways described above can be freely combined, superimposed without conflict.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalents and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention. The above is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the technical principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A stator punching sheet comprises a yoke ring (1) and a plurality of stator teeth (2) connected to the yoke ring (1), wherein the stator teeth (2) comprise tooth shoes, and the stator punching sheet is characterized in that the projection of the stator punching sheet on the radial surface of the stator punching sheet along the axial direction of the stator punching sheet, the shoe surfaces of the tooth shoes comprise a first circular arc section (31), a second circular arc section (32) and a third circular arc section (33) which are concentric with the circle center of the yoke ring (1), wherein the radius of the first circular arc section (31) is smaller than that of the second circular arc section (32), and the radius of the third circular arc section (33) is larger than that of the second circular arc section (32); the radius of the first arc section (31) is R1, the radius of the second arc section (32) is R2, the radius of the third arc section (33) is R3, the reference set value of a stator-rotor air gap formed after the stator punching sheet and a corresponding motor rotor are assembled is X, the radius of the arc section corresponding to the shoe surface corresponding to the stator-rotor air gap corresponding to X is R0, R0- (0.3-0.5) X is not less than R1 and is less than R0, R0 is not less than R2 and is not more than R0+ (0.3-0.5) X, and R0+ (0.3-0.5) X is not less than R3 and is not more than R0+ (0.6-0.9) X.

2. The stator punching sheet according to claim 1, wherein a central angle corresponding to the first circular arc section (31) is α 1, a central angle corresponding to the second circular arc section (32) is α 2, a central angle corresponding to the shoe surface is α 0,0 < α 1 < α 0/3, α 0/3 < α 2 < 2 α 0/3.

3. The stator punching sheet according to claim 2, characterized in that the central angle corresponding to the third arc segment (33) is α 3,0 < α 3 ≦ α 0/3.

4. The stator punching according to any one of claims 1 and 3, characterized in that the second arc segment (32) is located between the first arc segment (31) and the third arc segment (33).

5. The stator punching sheet according to claim 4, characterized in that two adjacent end points of the first circular arc segment (31) and the second circular arc segment (32) are connected through a first straight line segment (34), and/or two adjacent end points of the second circular arc segment (32) and the third circular arc segment (33) are connected through a second straight line segment (35).

6. The stator lamination as recited in claim 5, wherein the slope of the first straight line segment (34) is equal to the slope of the second straight line segment (35).

7. A motor stator, characterized in that, the stator punching sheet of any claim 1 to 6 is laminated to form.

8. An electrical machine comprising an electrical machine stator according to claim 7.

9. A vehicle characterized by comprising the electric machine of claim 8.