U-shaped three-section embedded asymmetric magnetic steel outer rotor and motor

Abstract

The utility model discloses a U-shaped three-section embedded asymmetrical magnetic steel external rotor and motor, the external rotor comprises a rotor iron core, and also comprises a plurality of magnetic steel groups uniformly distributed on the rotor iron core along the circumferential direction, each magnetic steel group comprises three sections of magnetic steel with the same thickness, the two ends of the magnetic steel are provided with magnetic bridges, and the magnetic bridges are connected with the rotor iron core. The three sections of magnetic steel are close to each other end to end and are distributed in an asymmetric U shape, a U-shaped opening formed by the three sections of magnetic steel faces the circle center of the rotor iron core, grooves which are opposite to the magnetic steel in number and are in one-to-one correspondence with the magnetic steel are formed in the rotor iron core, and the magnetic steel is embedded in the corresponding grooves. According to the U-shaped three-section embedded asymmetric magnetic steel outer rotor and the motor provided by the utility model, the magnetic steel is arranged in a U shape, so that magnetic flux can be better gathered, the magnetic flux utilization rate is improved, and the harmonic content and the torque ripple are reduced, thereby improving the performance and the stability of the motor.

Description

Technical Field

[0001] The utility model relates to the field of motor rotors. More specifically, the utility model relates to a U-shaped three-section embedded asymmetric magnet outer rotor and a motor. Background Art

[0002] Wind turbines usually adopt permanent magnet synchronous motors (PMSMs) as their core driving devices. Such motors utilize permanent magnets to generate a synchronous rotating magnetic field, achieving efficient energy conversion. According to the arrangement of permanent magnets, permanent magnet synchronous motors can be divided into surface permanent magnet synchronous motors (SPMSMs) and embedded permanent magnet synchronous motors (IPMSMs). Permanent magnet synchronous motors are widely used in the field of wind power generation due to their advantages such as high efficiency, simple structure, high power factor, and low losses.

[0003] The magnet arrangement methods of traditional permanent magnet synchronous motors mainly include two types: symmetric arrangement and asymmetric arrangement. These arrangement methods have some deficiencies in the single-direction working state:

[0004] 1. Magnets in symmetric arrangement are usually evenly distributed, with the same shape and magnetic properties for each pole magnet. Although this arrangement method has a simple structure, it has the following disadvantages:

[0005] Low efficiency: Symmetric arrangement cannot fully utilize the magnetic properties of the magnets under single-direction working conditions, resulting in a reduction in motor efficiency.

[0006] High harmonic content: Symmetric arrangement makes the air-gap magnetic density distribution uneven, increasing the total harmonic content of the motor and affecting the stability and efficiency of the motor.

[0007] Mechanical vibration and noise: Symmetric arrangement leads to large torque fluctuations, increasing the mechanical vibration and noise of the motor.

[0008] 2. Magnets in asymmetric arrangement are arranged asymmetrically by changing the length, angle, or shape of the magnets. Compared with symmetric arrangement, the asymmetric magnet arrangement has the following advantages:

[0009] Improved efficiency: Asymmetric arrangement can better utilize the magnetic properties of the magnets, improving the efficiency of the motor.

[0010] Reduced harmonic content: Asymmetric arrangement can optimize the air-gap magnetic density distribution, reducing the harmonic content of the motor and enhancing the stability of the motor.

[0011] Reduced vibration and noise: Asymmetric arrangement can reduce torque fluctuations, lower mechanical vibration and noise, and improve the running smoothness of the motor.

[0012] In addition to symmetric and asymmetric arrangements, the shape of the permanent magnets in a permanent magnet synchronous motor also affects its performance. Common magnet shapes include straight and V-shaped. The straight magnet is the simplest magnet shape, with the magnets arranged in a straight bar. Its advantages are simple design and manufacturing, but it has insufficient mechanical strength during high-speed rotation and poor performance in terms of magnetic flux concentration and harmonic control. The V-shaped magnet arrangement makes each pair of magnets arranged in a V shape. This arrangement can improve the magnetic flux concentration ability compared to the straight shape, reducing the cogging torque and harmonic content. However, the V-shaped magnets usually result in uneven distribution of magnetic flux in different paths, which may increase magnetic leakage, thereby reducing the utilization efficiency of the magnetic flux and affecting the overall performance of the motor. Summary of the Invention

[0013] The object of the present invention is to provide a U-shaped three-section embedded asymmetric magnet outer rotor and motor. By arranging the magnets in a U shape, it can better concentrate the magnetic flux, improve the magnetic flux utilization rate, reduce the harmonic content and torque ripple, thereby enhancing the performance and stability of the motor.

[0014] The technical solution of the present invention to solve the above technical problems is as follows: A U-shaped three-section embedded asymmetric magnet outer rotor includes a rotor core, and further includes:

[0015] Multiple groups of magnet groups evenly distributed circumferentially on the rotor core. Each magnet group includes three magnets with the same thickness. Both ends of each magnet are provided with magnetic bridges. The three magnets are close to each other at the head and tail and are arranged in an asymmetric U shape, and the U-shaped opening formed by them faces the center of the rotor core. Grooves corresponding to the number of magnets and in one-to-one correspondence are provided on the rotor core, and the magnets are embedded in the corresponding grooves.

[0016] Further, in the U-shaped three-section embedded asymmetric magnet outer rotor, among the three magnets of each magnet group, the lengths of the two end magnets located on both sides are different.

[0017] Further, in the U-shaped three-section embedded asymmetric magnet outer rotor, the angles between the middle magnet and the two side magnets are not equal and are both greater than 90°.

[0018] Further, in the U-shaped three-section embedded asymmetric magnet outer rotor, the angles between the two side magnets and the surface of the rotor core are both less than 90°.

[0019] Further, in the U-shaped three-section embedded asymmetric magnet outer rotor, the magnetization directions of the three magnets in each magnet group are the same.

[0020] Further, in the U-shaped three-section embedded asymmetric magnet outer rotor, the magnet groups are set to eight groups.

[0021] The present utility model also provides a permanent magnet synchronous motor, which includes the U-shaped three-section embedded asymmetric magnet outer rotor described in any one of the above.

[0022] The beneficial effects of the present utility model are as follows:

[0023] 1. For the U-shaped three-section embedded asymmetric magnet outer rotor of the present utility model, compared with the symmetric magnet structure, through the asymmetric magnet design, the harmonic distortion during the motor operation is effectively reduced under the unidirectional operation condition, and the noise and vibration are reduced.

[0024] 2. For the U-shaped three-section embedded asymmetric magnet outer rotor of the present utility model, through the design of the U-shaped structure, it has higher magnetic flux concentration and utilization rate compared with the I-shaped and V-shaped rotors, reduces magnetic flux leakage, provides better mechanical strength and electromagnetic performance, and is applicable to application scenarios requiring high power density and high efficiency.

[0025] 3. For the U-shaped three-section embedded asymmetric magnet outer rotor of the present utility model, the torque ripple is reduced through the structure of the asymmetric magnet, and the smooth operation performance and dynamic response performance of the motor are improved.

[0026] 4. The U-shaped three-section embedded asymmetric magnet outer rotor of the present utility model adopts an embedded magnet structure. The inductance of the q-axis of this structure is larger than that of the d-axis, making the armature reaction of the q-axis also relatively higher than that of the d-axis. The magnetic circuit saturation phenomenon occurs more simply, improving the magnetic flux utilization rate, optimizing the magnetic field distribution, reducing the magnetic flux distortion, and improving the efficiency and performance of the motor; at the same time, the embedded design improves the bonding strength between the magnet and the iron core, enhances the stability of the overall structure, reduces the later maintenance cost, and extends the service life of the motor.

[0027] Other advantages, objectives and features of the present utility model will be partially reflected by the following description, and partially will also be understood by those skilled in the art through the research and practice of the present utility model. Brief Description of the Drawings

[0028] Figure 1 It is a schematic structural diagram of the U-shaped three-section embedded asymmetric magnet outer rotor described in the present utility model;

[0029] Figure 2 It is a schematic structural diagram of the U-shaped three-section embedded asymmetric magnet outer rotor described in the present utility model;

[0030] Figure 3 It is a schematic structural diagram of the magnet group described in the present utility model. Detailed Description of the Embodiment

[0031] The following further detailed description of the present utility model is provided in conjunction with the drawings, so that those skilled in the art can implement it with reference to the text of the specification.

[0032] It should be noted that in the description of the present utility model, the orientation or positional relationship indicated by the terms "lateral", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to the present utility model.

[0033] Figures 1-3 A U-shaped three-section embedded asymmetric magnet outer rotor provided by an embodiment of the present utility model includes a rotor core 1, and further includes:

[0034] Eight magnet groups 2 evenly distributed along the circumferential direction on the rotor core 1. Each magnet group 2 includes three magnets 21 with the same thickness. Both ends of each magnet 21 are provided with magnetic bridges 22. The three magnets 21 are arranged end to end and are asymmetrically distributed in a U shape, and the U-shaped opening formed by them faces the center of the rotor core 1. Grooves corresponding to the number of magnets 21 are provided on the rotor core 1, and the magnets 21 are embedded in the corresponding grooves. The air gap of the outer rotor is on the side of the rotor close to the axis. The concentrating magnetic field and the air gap magnetic field generated on the side of the groove and the magnet 21 close to the air gap are also on the side of the rotor close to the axis;

[0035] Among them, as Figure 3 shown in, among the three magnets 21 of the magnet group 2, the lengths of the two magnets 21 at both sides are different. Figure 3 The length L2 of the magnet 21 on the right side in is greater than the length L1 of the magnet 21 on the left side, so that the angles θ2 and θ3 between the middle magnet 21 and the two magnets 21 on both sides are not equal and are both greater than 90°; the angles θ1 and θ4 between the two magnets 21 on both sides and the surface of the rotor core 1 are both less than 90°.

[0036] Furthermore, in the U-shaped three-section embedded asymmetric magnet outer rotor, the magnetization directions of the three magnets 21 of the magnet group 2 are the same. The magnetization directions of the three magnets 21 are kept consistent, or the N poles are uniformly oriented towards the center of the U shape formed by them, or the S poles are uniformly oriented towards the center of the U shape formed by them. As Figure 3 shown in, the N poles are uniformly oriented towards the center of the U shape formed by them.

[0037] The present utility model also provides a permanent magnet synchronous motor, including the above-mentioned U-shaped three-section embedded asymmetric magnet outer rotor.

[0038] Although the embodiments of the present utility model have been disclosed as above, it is not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present utility model. For those familiar with the field, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present utility model is not limited to the specific details and the embodiments shown and described herein.

Claims

1. A U-shaped three-section embedded asymmetric magnetic steel outer rotor, comprising a rotor core (1), characterized in that: Also includes: A plurality of groups of magnetic steel groups (2) uniformly distributed along the circumferential direction on the rotor core (1), the magnetic steel group (2) comprising three sections of magnetic steel (21) of the same thickness, magnetic bridges (22) being provided at both ends of the magnetic steel (21), the three sections of magnetic steel (21) being close to each other head to tail and being distributed in an asymmetric U-shape, and the U-shaped opening formed by them facing the center of the rotor core (1), the rotor core (1) being provided with grooves corresponding to the number of the magnetic steels (21) and one-to-one, and the magnetic steels (21) being embedded in the corresponding grooves.

2. A U-shaped three-section embedded asymmetric magnetic steel outer rotor as claimed in claim 1, characterized in that: Among the three sections of magnetic steel (21) of the magnetic steel group (2), the lengths of the magnetic steel (21) at two ends located on both sides are different.

3. A U-shaped three-section embedded asymmetric magnetic steel outer rotor as claimed in claim 2, characterized in that: The included angles between the magnetic steel (21) located in the middle and the two sections of the magnetic steel (21) located on both sides are not equal, and are both greater than 90°.

4. A U-shaped three-section embedded asymmetric magnetic steel outer rotor as claimed in claim 3, characterized in that: The included angles between the two sections of magnetic steel (21) located on both sides and the surface of the rotor core (1) are both less than 90°.

5. The U-shaped three-section embedded asymmetric magnetic steel outer rotor according to claim 1, characterized in that: The magnetization directions of the three sections of magnetic steel (21) of the magnetic steel group (2) are the same.

6. A U-shaped three-section embedded asymmetric magnetic steel outer rotor as claimed in claim 1, characterized in that: The magnetic steel groups (2) are arranged in eight groups.

7. A permanent magnet synchronous motor, characterized in that: It comprises a U-shaped three-section embedded asymmetric magnetic steel outer rotor as described in any one of claims 1-6.

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