Permanent magnet motor stator punching sheet structure and permanent magnet motor

Abstract

The invention discloses a permanent magnet motor stator punching sheet structure, and relates to the technical field of permanent magnet motors, the permanent magnet motor stator punching sheet structure comprises a stator iron core yoke part and a plurality of stator teeth, the stator iron core yoke part is provided with a hollow hole, and the plurality of stator teeth are arranged around the periphery of the stator iron core yoke part and along the radial direction of the hollow hole; one end of each of the plurality of stator teeth is connected with the hole wall of the hollow hole, and the other ends of the plurality of stator teeth are close to each other; an auxiliary groove is formed in one end, far away from the yoke part of the stator core, of each stator tooth, an included angle is formed between the extension direction of each auxiliary groove and the extension direction of each stator tooth, and the layout mode of the auxiliary grooves improves the air-gap flux density waveform of the unidirectional rotating high-speed permanent magnet motor, reduces the harmonic distortion rate of the air-gap flux density, and improves the reliability of the unidirectional rotating high-speed permanent magnet motor. Therefore, the rotor eddy current is reduced and the motor efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of permanent magnet motors, and in particular to a permanent magnet motor stator punching structure and a permanent magnet motor. Background Art

[0002] High-speed permanent magnet motors are widely used in CNC machine tools, fuel motor air compressors, various aerospace pumps and other fields. Two poles and six slots are the commonly used pole-slot combinations for high-speed and even ultra-high-speed permanent magnet motors. They have the advantages of short coil winding ends, high motor efficiency and simple process.

[0003] High-speed permanent magnet motors are affected by harmonic magnetic fields, and the permanent magnets, sheaths and other conductive structural components on their rotors will generate large eddy current losses, causing serious heating of the rotor, reduced motor efficiency, and even high-temperature demagnetization of the permanent magnets. One of the existing measures is to open auxiliary grooves in the stator tooth crowns. The auxiliary grooves are generally rectangular, triangular, arc-shaped, etc., and are symmetrically distributed along the center line of the teeth. However, this distribution of the auxiliary grooves can sometimes improve the eddy current losses of the rotor, but sometimes it will increase the eddy current losses of the rotor. Therefore, the opening of auxiliary grooves in the stator tooth crowns needs to be improved. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned technical deficiencies and propose a permanent magnet motor stator punching structure and a permanent magnet motor to solve the technical problem that the auxiliary grooves opened in the stator tooth crown of the permanent magnet motor in the prior art are symmetrically distributed along the midline, and this distribution method can sometimes improve the eddy current loss of the rotor, but sometimes increase the eddy current loss of the rotor.

[0005] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a permanent magnet motor stator punching structure, comprising: The stator core yoke is provided with a hollow hole; and A plurality of stator teeth are arranged at intervals along the circumferential side of the stator core yoke, one end of each of the stator teeth is connected to the hole wall of the hollow hole, and the other ends are close to each other; an auxiliary groove is provided at one end of each stator tooth away from the stator core yoke, and an extension direction of the auxiliary groove is arranged at an angle to an extension direction of the stator tooth.

[0006] In some embodiments, the plurality of stator teeth are arranged along the radial circumference of the hollow hole, and the ends of the stator teeth away from the stator core yoke have flanges extending toward both sides, and the plurality of flanges of the plurality of stator teeth enclose a receiving hole, and each of the auxiliary grooves is connected to the receiving hole.

[0007] In some embodiments, stator slots are formed between adjacent stator teeth, and each stator slot is provided with a coil winding.

[0008] In some embodiments, spacing grooves are formed between the flanges on adjacent stator teeth, and the spacing grooves connect the stator slots and the accommodating holes.

[0009] In some embodiments, the width of the auxiliary groove is between 1 / 16 and 1 / 2 of the width of the stator tooth.

[0010] In some embodiments, the minimum distance between the auxiliary groove and the side edge of the stator tooth is no greater than 1 / 8 of the width of the stator tooth.

[0011] In some embodiments, the receiving hole is circular, and a tangent line at an intersection of the receiving hole and the auxiliary groove and an extending direction of the auxiliary groove are arranged at an obtuse angle.

[0012] In a second aspect, the present invention further provides a permanent magnet motor, characterized in that it comprises a casing, a rotor and the above-mentioned permanent magnet motor stator punching structure, wherein the permanent magnet motor stator punching structure is fixedly arranged on the casing, and the rotor is rotatably arranged on the casing.

[0013] In some embodiments, the permanent magnet motor further includes a magnetic bar inserted between the plurality of stator teeth.

[0014] In some embodiments, the permanent magnet motor further includes an alloy sheath, and the alloy sheath is sleeved on the magnetic rod.

[0015] Compared with the prior art, the permanent magnet motor stator punching structure provided by the present invention can be installed on a permanent magnet motor and serve as the stator of the permanent magnet motor. The hollow hole of the stator core yoke has a plurality of circumferentially arranged stator teeth, and each stator tooth is provided with an auxiliary groove. The extension direction of the auxiliary groove is arranged at an angle to the extension direction of the stator tooth. This layout of the auxiliary groove improves the air gap magnetic flux waveform of the unidirectional rotating high-speed permanent magnet motor, reduces the harmonic distortion rate of the air gap magnetic flux, thereby reducing the rotor eddy current and improving the motor efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of a permanent magnet motor stator punching structure provided by an embodiment of the present invention; Figure 2 It is a schematic diagram of the structure of the permanent magnet motor stator punching structure provided by an embodiment of the present invention after the magnetic rod, alloy sheath and coil set are installed; Figure 3 is a radial air gap flux density waveform diagram of a permanent magnet motor provided by an embodiment of the present invention; Figure 4 It is the first twenty-order Fourier decomposition diagram of the radial magnetic flux waveform of the permanent magnet motor provided by the embodiment of the present invention; Figure 5 It is a curve diagram of the calculated value of the rotor eddy current loss of the permanent magnet motor provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0018] In order to solve the technical problem that the auxiliary grooves opened in the stator tooth crown of the permanent magnet motor in the prior art are distributed symmetrically along the midline, and this distribution method can sometimes improve the eddy current loss of the rotor, but sometimes increase the eddy current loss of the rotor, the present invention provides a permanent magnet motor stator punching structure, which can improve the air gap magnetic flux waveform of the unidirectional rotating high-speed permanent magnet motor, reduce the harmonic distortion rate of the air gap magnetic flux, reduce the eddy current loss of the rotor, and improve the motor efficiency.

[0019] It should be noted that the permanent magnet motor stator punching structure described in the present invention is used for but not limited to permanent magnet motors, etc. For the convenience of explanation, in the present invention, only the application of the permanent magnet motor stator punching structure to the permanent magnet motor is used as an example for explanation. The principle of applying the permanent magnet motor stator punching structure to other types of equipment is essentially the same as the principle applied to the permanent magnet motor, and will not be repeated here.

[0020] See also Figure 1 , Figure 1 The structure diagram of the permanent magnet motor stator sheet structure in one embodiment of the present invention includes a stator core yoke 1 and a plurality of stator teeth 2. The stator core yoke 1 is provided with a hollow hole 11. The plurality of stator teeth 2 surround the circumference of the stator core yoke 1 and are arranged along the radial direction of the hollow hole 11. The radial direction of the hollow hole 11 is a straight line passing through the center of the hollow hole 11. One end of the plurality of stator teeth 2 is connected to the hole wall of the hollow hole 11, and the other ends of the plurality of stator teeth 2 are close to each other. Figure 1 The embodiment shown has six stator teeth 2. An auxiliary groove 21 is provided at one end of each stator tooth 2 away from the stator core yoke 1. The extension direction of the auxiliary groove 21 is arranged at an angle with the extension direction of the stator tooth 2. The angle can be an acute angle or an obtuse angle, preferably an obtuse angle, which can further reduce the eddy current loss of the rotor and improve the efficiency of the motor.

[0021] Figure 1 The embodiment shown has a total of six auxiliary grooves 21, the six auxiliary grooves 21 are not symmetrical about any line, and the stator punching structure can only be along Figure 1 Rotate counterclockwise as indicated by the arrow.

[0022] In this embodiment, the shape of the stator core yoke 1 is a hollow circular wheel, and the hollow hole 11 inside it accommodates a plurality of stator teeth 2. The plurality of stator teeth 2 surround the circumference of the stator core yoke 1 and are arranged radially along the hollow hole 11. Each stator tooth 2 is provided with an auxiliary groove 21. The end of the auxiliary groove 21 away from the stator core yoke 1 passes through the stator tooth 2, and the extension direction of the auxiliary groove 21 is set at an obtuse angle to the extension direction of the stator tooth 2. When the permanent magnet motor is working, the harmonic distortion rate of its radial magnetic flux waveform is small, and the eddy current loss of the permanent magnet motor rotor is small.

[0023] The auxiliary groove 21 may be in a rectangular, triangular, diamond or other shapes. In this embodiment, the auxiliary groove 21 is preferably in a rectangular shape so as to reduce the eddy current loss of the permanent magnet motor rotor.

[0024] In one embodiment, see Figure 1 The end of the stator tooth 2 away from the stator core yoke 1 has flanges 22 extending toward both sides, and each stator tooth 2 has two flanges 22. The multiple flanges 22 of the multiple stator teeth 2 enclose a nearly circular receiving hole 12, and each auxiliary groove 21 is connected to the receiving hole 12. In this embodiment, the center of the receiving hole 12 coincides with the center of the stator core yoke 1. The side walls of the flanges 22 are arc-shaped and the curvature of all the flanges 22 is consistent, so that the receiving hole 12 is circular.

[0025] See also Figure 2 Furthermore, the permanent magnet motor stator punching structure also includes a magnetic bar 3, an alloy sheath 4 and a coil winding 5. The magnetic bar 3 and the alloy sheath 4 are both inserted between a plurality of stator teeth 2. Specifically, the magnetic bar 3 and the alloy sheath 4 are both provided with a receiving hole 12 and the central axes of the three are collinear. The alloy sheath 4 is sleeved on the magnetic bar 3. Stator slots 23 are formed between adjacent stator teeth 2, and each stator slot 23 is provided with a coil winding 5. In this embodiment, the magnetic bar 3 is used to generate a stable magnetic field, which interacts with the magnetic field generated by the coil winding 5 through the current, thereby realizing the conversion of electrical energy into mechanical energy.

[0026] In one embodiment, see Figure 1 The flanges 22 on adjacent stator teeth 2 are spaced apart to form spacing grooves 24, and the spacing grooves 24 connect the stator slots 23 and the receiving holes 12. Each stator tooth 2 has two flanges 22 on both sides. Figure 1 The illustrated embodiment has twelve flanges 22 in total, and the second flange 22 is formed with six spacing grooves 24. Each spacing groove 24 allows the magnetic bar 3 of the accommodating hole 12 to connect to the coil winding 5 of the stator slot 23, so that the magnetic field generated by the magnetic bar 3 and the magnetic field generated by the coil winding 5 can act more stably.

[0027] In one embodiment, see Figure 1The width of the auxiliary groove 21 is between 1 / 16 and 1 / 2 of the width of the stator tooth 2. Within this range, as the width of the auxiliary groove 21 increases, the eddy current loss of the motor rotor first decreases and then increases. Experiments have shown that when the width of the auxiliary groove 21 is 7 / 16 of the tooth width of the stator tooth 2, the eddy current loss of the motor rotor is the smallest.

[0028] In addition, the minimum distance between the auxiliary groove 21 and the side of the stator tooth 2 is no more than 1 / 8 of the width of the stator tooth 2, which is beneficial to improving the air gap flux waveform of the unidirectional rotating high-speed permanent magnet motor, reducing the harmonic distortion rate of the air gap flux, reducing the rotor eddy current, and improving the motor efficiency.

[0029] In one embodiment, see Figure 1 , the accommodating hole 12 is circular, and the tangent line of the intersection of the accommodating hole 12 and the auxiliary groove 21 and the extending direction of the auxiliary groove 21 are set at an obtuse angle. Specifically, the rotation direction of the rotor is Figure 1 In the counterclockwise direction of the embodiment shown, the tangent line of the intersection of the accommodating hole 12 and the auxiliary groove 21 toward the rotation direction of the rotor is arranged at an obtuse angle to the extension direction of the auxiliary groove 21. Figure 1 The obtuse angle of the embodiment shown is 120°. After multiple tests, it is found that when the obtuse angle is set to 120°, the eddy current loss of the rotor is minimized.

[0030] In a second aspect, the present invention further provides a permanent magnet motor, comprising a housing, a rotor and the above-mentioned permanent magnet motor stator sheet structure, wherein the permanent magnet motor stator sheet structure is fixedly arranged on the housing, and the rotor is rotatably arranged on the housing. The receiving hole 12 of the stator core yoke 1 is provided with a magnetic bar 3, and the stator slot 23 is provided with a coil winding 5. When the coil winding 5 is energized, the magnetic field generated by the current of the coil winding 5 interacts with the magnetic field generated by the magnetic bar 3, thereby driving the magnetic bar 3 to rotate at a high speed, so that the magnetic bar 3 drives the load to rotate.

[0031] Figure 3 The one with a larger fluctuation amplitude is the radial air gap flux waveform diagram of the permanent magnet motor that does not use the stator punching structure of the present invention, and the one with a smaller fluctuation amplitude is the radial air gap flux waveform diagram of the permanent magnet motor that uses the stator punching structure of the present invention. It can be seen that the radial air gap flux fluctuation of the permanent magnet motor that uses the stator punching structure of the present invention is smaller, and the air gap flux waveform is closer to a sine wave, which helps the motor to run more stably. The smaller air gap flux fluctuation helps to reduce the loss of the motor and improve the efficiency of the motor.

[0032] Figure 4 The left side of the exploded view shows the harmonic order of the permanent magnet motor using the stator punching structure of the present invention, and the right side shows the harmonic order of the permanent magnet motor not using the stator punching structure of the present invention. Figure 4It can be seen that the harmonic distortion rate of the radial magnetic flux waveform of the permanent magnet motor before the stator punching structure of the present invention is 26.0%, and the harmonic distortion rate of the radial magnetic flux waveform of the permanent magnet motor after the stator punching structure of the present invention is 21.8%. It can be seen that the harmonic distortion rate of the radial magnetic flux waveform of the permanent magnet motor using the stator punching structure of the present invention is significantly reduced. The lower harmonic distortion rate means that the air gap magnetic flux waveform is closer to the ideal sine waveform, which helps to reduce the torque fluctuation during the operation of the motor and improve the efficiency and stability of the motor.

[0033] Figure 5 The higher rotor eddy current loss per unit time is the calculated value curve of the rotor eddy current loss of the permanent magnet motor that does not use the stator punching structure of the present invention, and the lower rotor eddy current loss per unit time is the calculated value curve of the rotor eddy current loss of the permanent magnet motor that uses the stator punching structure of the present invention. It can be seen that the rotor eddy current loss of the permanent magnet motor using the stator punching structure of the present invention is lower, which can reduce energy loss and thus improve the efficiency of the motor.

[0034] In order to better understand the present invention, the following Figures 1 to 5 The technical solution of the present invention is described in detail: The permanent magnet motor stator punching structure provided by the present invention can be installed on a permanent magnet motor and serve as the stator of the permanent magnet motor. The hollow hole of the stator core yoke portion 1 has a plurality of circumferentially arranged stator teeth, and each stator tooth is provided with an auxiliary groove. The extension direction of the auxiliary groove is arranged at an angle to the extension direction of the stator tooth. This layout of the auxiliary groove improves the air gap magnetic flux waveform of the unidirectional rotating high-speed permanent magnet motor, reduces the harmonic distortion rate of the air gap magnetic flux, thereby reducing the rotor eddy current and improving the motor efficiency.

[0035] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A permanent magnet motor stator punching structure, characterized in that: include: The stator core yoke is provided with a hollow hole; and A plurality of stator teeth are arranged at intervals along the circumferential side of the stator core yoke, one end of each of the stator teeth is connected to the hole wall of the hollow hole, and the other ends are close to each other; an auxiliary groove is provided at one end of each stator tooth away from the stator core yoke, and an extension direction of the auxiliary groove is arranged at an angle to an extension direction of the stator tooth.

2. The permanent magnet motor stator punching structure according to claim 1, characterized in that: The plurality of stator teeth are arranged along the radial circumference of the hollow hole, and flanges are extended toward both sides from the ends of the stator teeth away from the stator core yoke. The plurality of flanges of the plurality of stator teeth enclose a receiving hole, and each of the auxiliary grooves is connected to the receiving hole.

3. The permanent magnet motor stator punching structure according to claim 2, characterized in that: Stator slots are formed between adjacent stator teeth, and each stator slot is provided with a coil winding.

4. The permanent magnet motor stator punching structure according to claim 3, characterized in that: Spacing grooves are formed between the flanges on adjacent stator teeth, and the spacing grooves communicate with the stator slots and the accommodating holes.

5. The permanent magnet motor stator punching structure according to claim 1, characterized in that: The width of the auxiliary groove is between 1 / 16 and 1 / 2 of the width of the stator tooth.

6. The permanent magnet motor stator punching structure according to claim 1, characterized in that: The minimum distance between the auxiliary groove and the side edge of the stator tooth is no greater than 1 / 8 of the width of the stator tooth.

7. The permanent magnet motor stator punching structure according to claim 2, characterized in that: The accommodating hole is circular, and a tangent line at an intersection of the accommodating hole and the auxiliary groove and an extending direction of the auxiliary groove are arranged at an obtuse angle.

8. A permanent magnet motor, characterized in that: It comprises a casing, a rotor and a permanent magnet motor stator punching structure as described in any one of claims 1 to 9, wherein the permanent magnet motor stator punching structure is fixedly arranged on the casing, and the rotor is rotatably arranged on the casing.

9. The permanent magnet motor according to claim 8, characterized in that: The permanent magnet motor further comprises a magnetic bar inserted between the plurality of stator teeth.

10. The permanent magnet motor according to claim 9, characterized in that: The permanent magnet motor further comprises an alloy sheath, and the alloy sheath is sleeved on the magnetic rod.

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