TYP permanent magnet motor rotor skew pole method

Abstract

The invention provides a TYP permanent magnet motor rotor skewed pole method, which has the advantages that a key slot reference and iron core skewed pole distribution are determined according to different stator slot numbers and pole pair numbers, a key slot included angle of skewed poles can be determined through calculation, and production of segmented skewed poles is realized. According to the invention, the skewed poles of the rotor are realized through the sectional distribution of the iron cores, so that the torque pulsation and the electromagnetic noise can be reduced; the skewed poles are realized on the rotor, so that the motor stator can adopt straight flutes and large-batch specifications, automatic winding and embedding can be realized, the production efficiency is improved, and the labor cost is reduced; the number of the laminations of each rotor section is equal, and the lamination directions of the punching sheets are consistent, so that tools in iron core manufacturing and the management cost caused by the tools can be greatly reduced, the production efficiency and the consistency of the quality of the rotor iron core are improved, and the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the rotor of a permanent magnet motor, and particularly to a method for skewing the poles of a permanent magnet motor rotor. Background Technology

[0002] With the continuous innovation and rapid development of modern industry, permanent magnet synchronous motors have attracted increasing attention due to their advantages such as compact structure, high energy density, and high efficiency. Variable frequency speed control permanent magnet synchronous motors (TYP) have advantages such as high energy density, high efficiency, and low cost, and have been favored by motor manufacturers and users both domestically and internationally in recent years.

[0003] Because permanent magnet motors have permanent magnets on their rotors, they cannot use skewed slots like asynchronous motors. Therefore, they often use straight slots on the rotor and skewed slots on the stator. However, in manufacturing, stator skewed cores are generally achieved using specialized tooling, making automated production difficult. Furthermore, automating stator winding in skewed slots is challenging, resulting in high labor costs. The skewed slotting process also increases copper wire length and winding difficulty. Existing automated winding processes for permanent magnet motor stator windings involve first making the stator core into straight slots, embedding the windings into the slots, then using specialized equipment and tooling to twist the stator core to the required skew angle before welding or crimping, thus improving winding production efficiency. With the increasing demand for variable frequency permanent magnet motors, rotor skew or segmented pole offsetting is often used in motor production to replace the stator skewed slotting process. Moreover, as the number of rotor core segments increases, the amplitude of cogging torque gradually decreases.

[0004] The existing methods for segmented skewed poles of permanent magnets generally determine the positions of the keyways and rotor laminations based on a fixed number of poles, thereby determining the number of segments in the iron core. Then, the rotation angle of the keyways and the number of slots for the segmented skewed poles are calculated. This requires different calculation methods for different numbers of poles and rotor lamination specifications, making it impossible to standardize the production process and affecting the efficiency and cost of the rotor skewed poles. Summary of the Invention

[0005] In view of this, the present invention provides a method for skewed pole production of a TYP permanent magnet motor rotor, which determines the keyway reference and core skewed pole distribution for different stator slot numbers and pole pairs, and can determine the keyway angle of the skewed poles through calculation, thereby realizing the production of segmented skewed poles.

[0006] This invention provides a method for skewed rotor of a TYP permanent magnet motor, the operation steps of which are as follows; The first step is to determine the number of stator slots (Z), the number of pole pairs (2P), the number of core segments (N), and the skewed pole method, i.e., single-sided skewed pole or double-sided skewed pole, and to determine the distance between the rotor skewed slots as one slot pitch. The second step is to determine the keyway angle (θ) based on the number of stator slots, pole pairs, and segments, using the following formula: θ = 360° / 2P + 360° / Z*N; After the keyway angle (θ) of the rotor lamination is determined, the centerline of two adjacent rotor laminations is taken as the centerline of the first keyway, and the angle between the centerline of the other keyway and the centerline of the first keyway is the keyway angle. The third step involves performing a slant operation based on the keyway angle (θ) and the number of core segments (N). A primary surface segment is set as the initial segment, with the centerline reference of the first keyway on the primary surface coinciding with the vertical centerline reference of the primary surface itself. The primary surface is located in the center segment of the core segment, i.e., segment N / 2 (N / 2 is an integer, or plus 1 for non-integer segments), extending outwards from the center segment to both sides, i.e., segments N / 2-1 and N / 2+1. Segment N / 2-1 is rotated clockwise by the keyway angle (θ) from the primary surface; segment N / 2-2 is rotated clockwise by twice the keyway angle (θ); segment N / 2+1 is rotated clockwise by the keyway angle (θ) from the primary surface, and then mirrored along the vertical centerline of the primary surface; segment N / 2+2 is rotated clockwise by twice the keyway angle (θ) from the primary surface, and then mirrored along the vertical centerline of the primary surface. This process is repeated sequentially towards both ends of the core. The fourth step is to install the rotor laminations according to the rotor lamination slot structure arrangement in the third step to achieve rotor skew poles.

[0007] Furthermore, the rotor uses a single keyway structure for its shaft.

[0008] Furthermore, the rotor lamination shaft hole adopts a three-keyway structure, with the other two keyways rotating clockwise and counterclockwise around the first keyway respectively by the keyway angle (θ).

[0009] Furthermore, the laminations of each rotor lamination on the iron core are aligned in the same direction, and each segment is fixed by riveting before a magnet is inserted.

[0010] Furthermore, when the skewed pole method adopts a single-sided skewed pole, the number of iron core segments is odd, and they are symmetrically distributed from the center to both ends.

[0011] Furthermore, when the skewed pole method adopts a double-sided skewed pole, the number of iron core segments is even, and the center segment is set as two segments, symmetrically distributed to both ends.

[0012] Furthermore, the iron core is processed separately according to the number of segments, and the rotor lamination slots on it are processed with the same specifications. They are then installed on the rotating shaft one by one according to the keyway angle (θ) in the third step. Beneficial effects

[0013] 1. This invention achieves rotor skew by distributing the iron core in a segmented manner, which can reduce torque pulsation and electromagnetic noise. If the rotor skew angle is equal to the period angle corresponding to the cogging torque, the fundamental wave of the cogging torque can be eliminated.

[0014] 2. By implementing skewed poles on the rotor, this invention allows the motor stator to use straight slots. For large-volume production, the winding and embedding can be automated, improving production efficiency and reducing labor costs.

[0015] 3. Because the number of laminations in each rotor section is equal and the lamination direction is consistent, this invention can significantly reduce the tooling and management costs in core manufacturing, improve production efficiency and the consistency of rotor core quality, and reduce production costs.

[0016] 4. This invention obtains the keyway angle through a calculation formula, and can flexibly adjust the length and number of segments of the iron core according to different needs.

[0017] 5. This invention utilizes a single-key structure for the rotating shaft, which improves the shaft's versatility and reduces processing difficulty and management costs. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below.

[0019] The accompanying drawings described below are only related to some embodiments of the invention and are not intended to limit the invention.

[0020] In the attached diagram: Figure 1-5 Cross-sectional views of segments A, B, C, D, and E are shown in one embodiment of the present invention; Figure 6 A front view of the rotating shaft in one embodiment of the present invention is shown; Figure 7 A slanted pole unfolded diagram according to one embodiment of the present invention is shown; Figure 8-12 Cross-sectional views of segments A, B, C, D, and E are shown in another embodiment of the present invention; Figure 13 A front view of the rotating shaft is shown in another embodiment of the present invention; Figure 14 A slanted pole unfolded diagram of another embodiment of the present invention is shown. Detailed Implementation

[0021] To make the objectives, solutions, and advantages of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Unless otherwise stated, the terms used herein have their ordinary meanings in the art. The same reference numerals in the drawings represent the same parts.

[0022] like Figure 1 As shown, in one embodiment: This invention provides a method for skewed rotor of a TYP permanent magnet motor, the operation steps of which are as follows; The first step is to determine that the number of stator slots (Z) is 36, the number of pole pairs (2P) is 6, the number of core segments (N) is 5, and the skewed pole method is single-sided skewed pole. The distance between the rotor skewed slots is determined to be one slot pitch. The second step is to determine the keyway angle (θ) based on the number of stator slots, pole pairs, and segments, using the following formula: θ=360° / 2P + 360° / Z*N=360° / 2*3+ 360° / 36*5=62°; After the keyway included angle (θ) of the rotor lamination is determined, the rotor lamination shaft hole adopts a three-key structure. The centerline of the two magnetic poles of the lamination is used as the centerline reference of the first keyway, rotated 62° counterclockwise as the centerline reference of the second keyway, and then rotated 62° counterclockwise as the centerline reference of the third keyway. The third step involves performing a slanted pole operation based on the keyway angle (θ=62°) and the number of core segments (N=5). The core is divided into five segments: A, B, C, D, and E. Segment C is designated as the original surface segment. On segment C, the centerline reference of the first keyway coincides with the centerline reference in the vertical direction. The original surface is located at the center of the core segments, extending outwards to both sides, namely segments A, B, D, and E. Segment B is rotated clockwise from the original surface by the keyway angle (θ=62°). Segment A is rotated clockwise from the original surface by twice the keyway angle (θ=62°), i.e., 124°. Segment D is rotated clockwise from the original surface by the keyway angle (θ=62°) and then mirrored along the vertical centerline of the original surface. Segment E is rotated clockwise from the original surface by twice the keyway angle (θ=62°), i.e., 124°, and then mirrored along the vertical centerline of the original surface. The core segments A, B, C, D, and E are then sequentially assembled onto the rotating shaft. The fourth step is to install the rotor laminations according to the rotor lamination slot structure arrangement in the third step to achieve rotor skew poles.

[0023] As shown in the figure, the relative positions of each segment installed on the rotating shaft are as follows: with segment C as the reference plane of the rotor core, the rotating shaft is fitted with the first keyway and key. Segment B, viewed from the shaft extension angle towards the tail end of the shaft, rotates clockwise by θ = 62° from the reference plane. Segment A rotates clockwise by 2θ = 124° from the reference plane. Segment D rotates clockwise by θ = 62° from the reference plane and then mirrors it along the vertical center line. Segment E rotates clockwise by 2θ = 124° from the reference plane and then mirrors it along the vertical center line.

[0024] A single-sided slanted pole target with a slot pitch angle is achieved by using a slanted pole method.

[0025] As shown in the figure, in another embodiment... This invention provides a method for skewed rotor of a TYP permanent magnet motor, the operation steps of which are as follows; The first step is to determine that the number of stator slots (Z) is 72, the number of pole pairs (2P) is 8, the number of core segments (N) is 10, and the skewed pole method is double-sided skewed pole. The distance between the rotor skewed slots is determined to be one slot pitch. The second step is to determine the keyway angle (θ) based on the number of stator slots, pole pairs, and segments, using the following formula: θ=360° / 2P + 360° / Z*N=360° / 2*4+ 360° / 72*5=46°; After the keyway included angle (θ) of the rotor lamination is determined, the rotor lamination shaft hole adopts a three-key structure. The center line of the two magnetic poles of the lamination is used as the center line reference of the first keyway, rotated 46° counterclockwise as the center line reference of the second keyway, and then rotated 46° counterclockwise as the center line reference of the third keyway. The third step involves performing a skewed operation based on the keyway angle (θ=46°) and the number of core segments (N=10). The core is divided into ten segments: ABCDEEDCBA. Two C segments are designated as origin faces. On segment C, the centerline reference of the first keyway coincides with the centerline reference in the vertical direction. The origin face is located at the center of the core segments, extending outwards to both sides, namely segments A and B, and segments D and E. Segment B rotates clockwise from the origin face by the keyway angle (θ=46°). 6°), wherein segment A is rotated clockwise from the original surface by twice the keyway angle (θ=46°), i.e., 92°, wherein segment D is rotated clockwise from the original surface by the keyway angle (θ=46°), and then mirrored according to the vertical center line of the original surface, wherein segment N / 2+2 is rotated clockwise from the original surface by twice the keyway angle (θ=46°), i.e., 92°, and then mirrored according to the vertical center line of the original surface; then the arrangement is repeated from segment E to segment A, and the iron core segments ABCDEEDCBA are assembled onto the rotating shaft in sequence; The fourth step is to install the rotor laminations according to the rotor lamination slot structure arrangement in the third step to achieve rotor skew poles.

[0026] As shown in the figure, segment C is set as the reference; segment A is obtained by rotating segment C clockwise by 2θ = 92° and then mirroring it along the vertical line; segment B is obtained by rotating segment C clockwise by θ = 46° and then mirroring it along the vertical line; segment D is obtained by rotating segment C clockwise by θ = 46°; segment E is obtained by rotating segment C clockwise by 2θ = 92°. Install them on the rotating shaft in the order ABCDEEDCBA.

[0027] A slanted pole target with a slot pitch angle is achieved by using a double-sided slanted pole method.

[0028] Therefore, different stator slot numbers and core lengths can be met by using single-sided or double-sided skewed poles. The original production method that required special tooling can be changed to the production of a single core section. Only by adding different angles of the keyway can the same rotor lamination slots be arranged to achieve the purpose of skewed poles. There is no need to add tooling and special processes for skewed pole requirements, which improves production efficiency and reduces production costs.

[0029] The above description is merely an exemplary embodiment of the present invention and is not intended to limit the scope of protection of the present invention, which is determined by the appended claims.

Claims

1. A method for skewed pole design of a TYP permanent magnet motor rotor, characterized in that, The operation steps are as follows; The first step is to determine the number of stator slots (Z), the number of pole pairs (2P), the number of core segments (N), and the skewed pole method, i.e., single-sided skewed pole or double-sided skewed pole, and to determine the distance between the rotor skewed slots as one slot pitch. The second step is to determine the keyway angle (θ) based on the number of stator slots, pole pairs, and segments, using the following formula: θ = 360° / 2P + 360° / Z*N; After the keyway angle (θ) of the rotor lamination is determined, the centerline of two adjacent rotor laminations is taken as the centerline of the first keyway, and the angle between the centerline of the other keyway and the centerline of the first keyway is the keyway angle. The third step involves performing a slanted pole operation based on the keyway angle (θ) and the number of core segments (N). A primary surface segment is set as the initial segment. The centerline reference of the first keyway on the primary surface coincides with the vertical centerline reference of the primary surface itself. The primary surface is located in the center segment of the core segment, i.e., segment N / 2 (N / 2 is an integer, or plus 1 for non-integer segments). It extends outwards from the center segment to both sides, i.e., segments N / 2-1 and N / 2+1. Segment N / 2-1 rotates clockwise from the primary surface by the keyway angle (θ). Segment N / 2-2 rotates clockwise from the primary surface by twice the keyway angle (θ). Segment N / 2+1 rotates clockwise from the primary surface by the keyway angle (θ), and then mirrors the primary surface along its vertical centerline. Segment N / 2+2 rotates clockwise from the primary surface by twice the keyway angle (θ), and then mirrors the primary surface along its vertical centerline. This process is repeated sequentially towards both ends of the core. The fourth step is to install the rotor laminations according to the rotor lamination slot structure arrangement in the third step to achieve rotor skew poles.

2. The method for skewed pole method of TYP permanent magnet motor rotor according to claim 1, characterized in that, The rotor uses a single keyway structure for its shaft.

3. The method for skewed poles of a TYP permanent magnet motor rotor according to claim 1, characterized in that, The rotor lamination shaft hole adopts a three-keyway structure, and the other two keyways rotate clockwise and counterclockwise around the first keyway respectively, rotating the keyway included angle (θ).

4. The method for skewed pole method of TYP permanent magnet motor rotor according to claim 1, characterized in that, The laminations of each rotor lamination on the iron core are stacked in the same direction. Each segment is fixed by riveting and then a magnet is inserted.

5. The method for skewed pole method of TYP permanent magnet motor rotor according to claim 1, characterized in that, When the skewed pole method adopts a single-sided skewed pole, the number of core segments is odd, and they are symmetrically distributed from the center to both ends.

6. The method for skewed poles of a TYP permanent magnet motor rotor according to claim 1, characterized in that, When the skewed pole method adopts a double-sided skewed pole, the number of core segments is even, and the center segment is set as two segments, symmetrically distributed to both ends.

7. The method for skewed pole method of TYP permanent magnet motor rotor according to claim 1, characterized in that, The iron core is processed separately according to the number of segments, and the rotor lamination slots on it are processed with the same specifications. They are then installed on the rotating shaft one by one according to the keyway angle (θ) in the third step.

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