Built-in permanent magnet motor rotor and permanent magnet motor

Abstract

Embodiments of the present invention disclose an embedded permanent magnet motor rotor and a permanent magnet motor having the embedded permanent magnet motor rotor. The embedded permanent magnet motor rotor includes a first rotor lamination and a second rotor lamination, the first and second rotor laminations being arranged in the axial direction of the permanent magnet motor rotor, wherein the outer peripheral contour of at least one of the first and second rotor laminations includes a plurality of arcs whose centers are not on the axis of the permanent magnet motor rotor. Employing the embedded permanent magnet motor rotor according to embodiments of the present invention and the permanent magnet motor having the embedded permanent magnet motor rotor, for example, can reduce cogging torque.

Description

Technical Field

[0001] Embodiments of the present invention relate to a built-in permanent magnet motor rotor and a permanent magnet motor having the built-in permanent magnet motor rotor. Background Technology

[0002] Traditional permanent magnet motors consist of a stator and a rotor with an embedded permanent magnet installed in the stator. To reduce cogging torque, a non-uniform air gap is typically used. Summary of the Invention

[0003] The purpose of embodiments of the present invention is to provide a built-in permanent magnet motor rotor and a permanent magnet motor having the built-in permanent magnet motor rotor, thereby enabling, for example, a reduction in cogging torque.

[0004] An embodiment of the present invention provides an embedded permanent magnet motor rotor, which includes: a first rotor lamination and a second rotor lamination, the first rotor lamination and the second rotor lamination being arranged in the axial direction of the permanent magnet motor rotor, wherein the outer peripheral contour of at least one of the first rotor lamination and the second rotor lamination includes a plurality of arcs whose centers are not on the axis of the permanent magnet motor rotor.

[0005] According to an embodiment of the present invention, the built-in permanent magnet motor rotor further includes: a permanent magnet; and a rotor core, the rotor core including a first rotor lamination and a second rotor lamination, and having a permanent magnet slot, each of the first rotor lamination and the second rotor lamination having an opening for forming the permanent magnet slot, the permanent magnet being accommodated in the permanent magnet slot, and on a plane perpendicular to the axial direction, the center of the arc corresponding to the permanent magnet slot is approximately on the symmetry center line of the permanent magnet, and is closer to the outer periphery of the permanent magnet motor rotor than the axis of the permanent magnet motor rotor.

[0006] According to an embodiment of the present invention, the centers of the arcs corresponding to the same permanent magnet slot of the first rotor lamination and the second rotor lamination do not coincide in the axial direction.

[0007] According to an embodiment of the present invention, the radii of the arcs corresponding to the same permanent magnet slot of the first rotor lamination and the second rotor lamination are different.

[0008] According to an embodiment of the present invention, the maximum distance between the outer periphery of the first rotor lamination and the second rotor lamination and the axis of the permanent magnet motor rotor is approximately equal.

[0009] According to an embodiment of the present invention, the pole arc angles of the first rotor lamination and the second rotor lamination may be the same or different.

[0010] According to an embodiment of the present invention, the radii of the arcs corresponding to the same permanent magnet slot of the first rotor lamination and the second rotor lamination are different.

[0011] According to an embodiment of the present invention, the polar arc angle of the rotor lamination with the smaller arc radius in the first rotor lamination and the second rotor lamination is smaller than the polar arc angle of the rotor lamination with the larger arc radius in the first rotor lamination and the second rotor lamination.

[0012] According to an embodiment of the present invention, each of the first rotor lamination and the second rotor lamination includes one or more laminations.

[0013] According to an embodiment of the present invention, each of the first rotor lamination and the second rotor lamination includes a plurality of laminations having the same shape.

[0014] According to an embodiment of the present invention, the built-in permanent magnet motor rotor further includes: a permanent magnet; and a rotor core, the rotor core including a first rotor lamination and a second rotor lamination, and having a permanent magnet slot, each of the first rotor lamination and the second rotor lamination having an opening for forming the permanent magnet slot, one or more permanent magnets being accommodated in the permanent magnet slot, and at least one permanent magnet being simultaneously located in the opening of the first rotor lamination and the second rotor lamination.

[0015] According to an embodiment of the present invention, the ratio of the overlapping area of ​​the openings of the first rotor lamination and the second rotor lamination to the area of ​​the opening of the first rotor lamination or the second rotor lamination is greater than or equal to 60%.

[0016] According to an embodiment of the present invention, the ratio of the overlapping area of ​​the openings of the first rotor lamination and the second rotor lamination to the area of ​​the opening of the first rotor lamination or the second rotor lamination is less than or equal to 98%.

[0017] According to an embodiment of the present invention, the ratio of the cross-sectional area of ​​the permanent magnet to the overlapping area is greater than or equal to 50%.

[0018] According to an embodiment of the present invention, the rotor lamination with a smaller arc radius in the first rotor lamination and the rotor lamination with a larger arc radius in the second rotor lamination are small arc radius rotor laminations, and the rotor lamination with a larger arc radius in the first rotor lamination and the rotor lamination with a larger arc radius in the second rotor lamination are large arc radius rotor laminations, and the thickness of the small arc radius rotor lamination is greater than the thickness of the large arc radius rotor lamination.

[0019] According to an embodiment of the present invention, the inner hole of the rotor lamination with a small arc radius is circular, while the inner hole of the rotor lamination with a large arc radius is a regular polygon.

[0020] According to an embodiment of the present invention, the radius of the inner hole of the rotor lamination with a small arc radius is greater than the radius of the inscribed circle of the inner hole of the regular polygon of the rotor lamination with a large arc radius.

[0021] According to an embodiment of the present invention, the radius of the inner hole of the rotor lamination with a small arc radius is smaller than the radius of the circumscribed circle of the inner hole of the regular polygon of the rotor lamination with a large arc radius.

[0022] According to an embodiment of the present invention, the radii of the plurality of arcs of each rotor lamination in the first rotor lamination and the second rotor lamination are approximately the same.

[0023] Embodiments of the present invention also provide a permanent magnet motor, which includes: a stator; and the aforementioned built-in permanent magnet motor rotor disposed in the stator.

[0024] According to an embodiment of the present invention, the number of stator slots per pole per phase of the permanent magnet motor is 1.

[0025] By employing an embedded permanent magnet motor rotor according to an embodiment of the present invention and a permanent magnet motor having the embedded permanent magnet motor rotor, cogging torque can be reduced, for example. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a built-in permanent magnet motor rotor according to an embodiment of the present invention;

[0027] Figure 2a , 2b 2c are schematic diagrams of the first rotor lamination, the second rotor lamination, and the first and second rotor laminations in an assembled state, respectively, according to an embodiment of the present invention.

[0028] Figure 3a This is a schematic diagram of the rotor laminations of an embedded permanent magnet motor rotor according to an embodiment of the present invention, showing the overlapping portions of the openings of the rotor laminations for forming permanent magnet slots;

[0029] Figure 3b yes Figure 3a The diagram shows a rotor lamination of a built-in permanent magnet motor rotor, where permanent magnets are placed in the overlapping portion;

[0030] Figure 3c yes Figure 3b A magnified view of a portion of the 3C components;

[0031] Figure 4 This is a schematic diagram of the rotor laminations of a built-in permanent magnet motor rotor according to an embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of the first and second rotor laminations of an embedded permanent magnet motor rotor according to an embodiment of the present invention in an assembled state; and

[0033] Figure 6a , 6b6c are schematic diagrams of the first rotor lamination, the second rotor lamination, and the first and second rotor laminations in an assembled state, respectively, according to an embodiment of the present invention. Detailed Implementation

[0034] See Figure 1 According to an embodiment of the present invention, a permanent magnet motor includes a stator and a built-in permanent magnet motor rotor 100 disposed in the stator. According to an embodiment of the present invention, the number of stator slots per pole and per phase of the permanent magnet motor is one. According to an embodiment of the present invention, because the number of stator slots per pole and per phase of the motor is one, motor vibration and noise caused by radial force can be reduced. However, this also increases the cogging torque of the motor. While conventional methods may employ stator skew or rotor skew, the embodiments of the present invention effectively reduce cogging torque without employing skewed poles or slots.

[0035] like Figure 1 As shown, the built-in permanent magnet motor rotor 100 according to an embodiment of the present invention includes two or more rotor laminations 10. The rotor laminations 10 may have multiple rivet holes 15, which are used to fasten the rotor laminations 10 together. The rotor laminations 10 may also have self-locking buckles 17, which connect the rotor laminations 10 together. The rotor laminations 10 have inner holes 16, and the rotor shaft 20 mates with the inner holes 16.

[0036] See Figure 2a , 2b According to embodiments of the present invention, the built-in permanent magnet motor rotor 100 includes: a first rotor lamination 10A and a second rotor lamination 10B, the first rotor lamination 10A and the second rotor lamination 10B being arranged in the axial direction of the permanent magnet motor rotor 100, and the outer peripheral contour of at least one of the first rotor laminations 10A and the second rotor lamination 10B including a plurality of arcs 12 whose centers are not on the axis O of the permanent magnet motor rotor 100. The first rotor lamination 10A and the second rotor lamination 10B can be alternately stacked as a group of one or more. According to examples of the present invention, multiple (e.g., two, three or more) different rotor laminations 10 can be alternately stacked as a group of one or more. Figure 4 As shown, between the two poles, the arcs 12 can intersect, or there can be straight lines, arcs, etc. serving as transition lines 19 between the arcs 12.

[0037] See Figure 1 , 2aAccording to embodiments of the present invention, the built-in permanent magnet motor rotor 100 includes: a permanent magnet 30; and a rotor core 50. The rotor core 50 includes a first rotor lamination 10A and a second rotor lamination 10B and has a permanent magnet slot 51. Each of the first rotor lamination 10A and the second rotor lamination 10B has an opening 11 for forming the permanent magnet slot 51. The permanent magnet 30 is accommodated in the permanent magnet slot 51. In a plane perpendicular to the axial direction, the center of the arc 12 corresponding to the permanent magnet slot 51 is approximately on the symmetry center line of the permanent magnet 30 and is closer to the outer periphery of the permanent magnet motor rotor 100 than the axis of the permanent magnet motor rotor 100. The permanent magnet 30 may be cuboid in shape. Each of the first rotor lamination 10A and the second rotor lamination 10B includes one or more laminations. Each of the first rotor lamination 10A and the second rotor lamination 10B may include multiple laminations having the same shape.

[0038] See Figure 1 , 2a According to an embodiment of the present invention, the radii of the arcs 12 corresponding to the same permanent magnet slot 51 for the first rotor lamination 10A and the second rotor lamination 10B are r1 and r2, respectively. The centers of the arcs 12 corresponding to the same permanent magnet slot 51 for the first rotor lamination 10A and the second rotor lamination 10B are O1 and O2, respectively. The centers O1 and O2 of the arcs 12 corresponding to the same permanent magnet slot 51 for the first rotor lamination 10A and the second rotor lamination 10B do not coincide in the axial direction of the permanent magnet motor rotor 100. The radii of the arcs 12 corresponding to the same permanent magnet slot 51 for the first rotor lamination 10A and the second rotor lamination 10B can be different. The maximum distance between the outer periphery of the first rotor lamination 10A and the second rotor lamination 10B and the axis of the permanent magnet motor rotor 100 can be approximately equal. The radii of the arcs 12 corresponding to the same permanent magnet slot 51 in the first rotor lamination 10A and the second rotor lamination 10B can be different. The radii of the multiple arcs 12 in each of the first rotor lamination 10A and the second rotor lamination 10B can be approximately the same.

[0039] See Figure 5 The pole arc angles of the first rotor lamination 10A and the second rotor lamination 10B can be the same or different, while the radii of the arcs 12 of the first rotor lamination 10A and the second rotor lamination 10B can be different. More specifically, the pole arc angle β1 of the rotor lamination with the smaller radius of the arc 12 in the first rotor lamination 10A and the second rotor lamination 10B is smaller than the pole arc angle β2 of the rotor lamination with the larger radius of the arc 12 in the first rotor lamination 10A and the second rotor lamination 10B. The straight line defining the pole arc angle passes through the center of the inner hole 16 of the rotor lamination 10 and the endpoint of the long side 111 of the opening 11 away from the center of the inner hole 16.

[0040] See Figure 2a , 2b According to an embodiment of the present invention, the built-in permanent magnet motor rotor 100 further includes: a permanent magnet 30; and a rotor core 50, the rotor core 50 including a first rotor lamination 10A and a second rotor lamination 10B and having a permanent magnet slot 51, each of the first rotor lamination 10A and the second rotor lamination 10B having an opening 11 for forming the permanent magnet slot 51, one or more permanent magnets 30 being accommodated in the permanent magnet slot 51, and at least one permanent magnet 30 being simultaneously located in the opening 11 of the first rotor lamination 10A and the second rotor lamination 10B. The ratio of the overlapping area of ​​the openings 11 of the first rotor lamination 10A and the second rotor lamination 10B to the area of ​​the opening of the first rotor lamination or the second rotor lamination can be greater than or equal to 60%, and the ratio of the overlapping area of ​​the openings 11 of the first rotor lamination 10A and the second rotor lamination 10B to the area of ​​the opening of the first rotor lamination or the second rotor lamination is less than or equal to 98%. This avoids the magnetic leakage caused by an excessively wide magnetic bridge in each rotor lamination, which would lead to a decrease in torque. The overlapping portion forms an axially permeable permanent magnet receiving hole, and one or more permanent magnets 30 are placed in the permanent magnet receiving hole. The ratio of the cross-sectional area of ​​the permanent magnet 30 to the overlapping area can be greater than or equal to 50%. The permanent magnet 30 can have a rectangular cross-section. Since the area of ​​the openings 11 used to form the permanent magnet slots 51 of different laminations may be different, the ratio of the overlapping area to the area of ​​each opening 11 is not the same. The ratio of the overlapping area of ​​the openings 11 of the first rotor lamination 10A and the second rotor lamination 10B to the area of ​​the opening of the first rotor lamination or the second rotor lamination can be greater than or equal to 60%.

[0041] exist Figure 2c In the illustrated embodiment, the overlap is 97.2%, and the permanent magnet 30 is placed in the overlap portion (permanent magnet receiving hole). The cross-sectional area of ​​the permanent magnet 30 accounts for approximately 87% of the area of ​​the overlap portion. Figure 3a , 3b In the illustrated embodiment, the ratio of the overlapping portion 110 of the openings 11 of the first rotor lamination 10A and the second rotor lamination 10B to their respective areas is 83.3%. A permanent magnet 30 is placed in the overlapping portion (permanent magnet receiving hole), and the cross-sectional area of ​​the permanent magnet 30 occupies approximately 62% of the area of ​​the overlapping portion. To fix the permanent magnet 30, epoxy resin can be injected into the remaining gaps in the permanent magnet receiving hole.

[0042] In embodiments of the present invention, such as Figure 3b and 3cAs shown, the permanent magnet slot 51 includes a first slot 51A located in the middle and second slots 51B located on both sides of the first slot. The permanent magnet 30 includes a first permanent magnet 30A located in the first slot 51A and a second permanent magnet 30B located in the second slot 51B. Because the first rotor lamination 10A and the second rotor lamination 10B do not completely overlap on both sides of each corresponding U-shaped magnetic pole, and when a rectangular second permanent magnet 30B is used, the size of the second permanent magnet 30B will be smaller than the second slot 51B at the corresponding positions of the first rotor lamination 10A and the second rotor lamination 10B, thus forming a narrow air gap 52 (see...). Figure 3c This will increase the magnetic reluctance at that location. To compensate for the increased magnetic reluctance, the second permanent magnet 30B will be a permanent magnet model with a higher remanence than the first permanent magnet 30A.

[0043] In an embodiment of the present invention, see Figure 6a , 6b 6c, the rotor lamination with the smaller radius of the arc 12 in the first rotor lamination 10A and the second rotor lamination 10B is a small arc radius rotor lamination, and the rotor lamination with the larger radius of the arc 12 in the first rotor lamination 10A and the second rotor lamination 10B is a large arc radius rotor lamination. The thickness of the small arc radius rotor lamination is greater than the thickness of the large arc radius rotor lamination. Since the equivalent air gap corresponding to the rotor lamination with the smaller arc 12 radius is larger, a thicker rotor lamination can be used without significantly increasing rotor losses. According to an example of the present invention, the inner hole 16 of the small arc radius rotor lamination is circular, while the inner hole 16 of the large arc radius rotor lamination is a regular polygon. The radius of the inner hole 16 of the small arc radius rotor lamination can be greater than the radius of the inscribed circle of the regular polygonal inner hole 16 of the large arc radius rotor lamination. And the radius of the inner hole 16 of the small arc radius rotor lamination can be smaller than the radius of the circumscribed circle of the regular polygonal inner hole 16 of the large arc radius rotor lamination. Therefore, when the rotor shaft 20 is pressed into the inner hole 16, the edges of the polygonal inner hole 16 have sufficient deformation space to reduce the pressing force of the rotor shaft.

[0044] By employing an embedded permanent magnet motor rotor according to an embodiment of the present invention and a permanent magnet motor having the embedded permanent magnet motor rotor, cogging torque can be reduced, for example.

[0045] The above embodiments describe the first rotor lamination 10A and the second rotor lamination 10B, but the built-in permanent magnet motor rotor can have more types of rotor laminations.

[0046] Furthermore, the above embodiments of the present invention can be combined to form new embodiments.

Claims

1. A built-in permanent magnet motor rotor, comprising: The first rotor lamination and the second rotor lamination are arranged in the axial direction of the permanent magnet motor rotor, wherein the outer peripheral contours of the first rotor lamination and the second rotor lamination include a plurality of arcs whose centers are not on the axis of the permanent magnet motor rotor; permanent magnet; as well as The rotor core includes a first rotor lamination and a second rotor lamination, and has a permanent magnet slot. Each of the first rotor lamination and the second rotor lamination has an opening for forming the permanent magnet slot. The permanent magnet is accommodated in the permanent magnet slot. On a plane perpendicular to the axial direction, the center of the arc corresponding to the permanent magnet slot is approximately on the symmetry center line of the permanent magnet and is closer to the outer periphery of the permanent magnet motor rotor than the axis of the permanent magnet motor rotor. In this configuration, the first rotor lamination and the second rotor lamination are different rotor laminations, and they are stacked alternately in groups of one or more. The rotor lamination with the smaller arc radius in the first and second rotor laminations is a small arc radius rotor lamination, and the rotor lamination with the larger arc radius in the first and second rotor laminations is a large arc radius rotor lamination. The inner hole of the small arc radius rotor lamination is circular, while the inner hole of the large arc radius rotor lamination is a regular polygon. The centers of the arcs corresponding to the same permanent magnet slot in the first and second rotor laminations do not coincide in the axial direction. The radii of the arcs corresponding to the same permanent magnet slot in the first and second rotor laminations are different. Among them, the polar arc angle of the rotor lamination with the smaller arc radius in the first rotor lamination and the rotor lamination with the larger arc radius is smaller than the polar arc angle of the rotor lamination with the larger arc radius in the first rotor lamination and the rotor lamination with the larger arc radius.

2. The built-in permanent magnet motor rotor according to claim 1, wherein: The maximum distance between the outer periphery of the first rotor lamination and the second rotor lamination and the axis of the permanent magnet motor rotor is approximately equal.

3. The built-in permanent magnet motor rotor according to claim 1, wherein: The pole arc angles of the first rotor lamination and the second rotor lamination may be the same or different.

4. The built-in permanent magnet motor rotor according to claim 1 or 3, wherein: The radii of the arcs corresponding to the same permanent magnet slot are different for the first rotor lamination and the second rotor lamination.

5. The built-in permanent magnet motor rotor according to claim 1, wherein: Each of the first rotor lamination and the second rotor lamination includes one or more laminations.

6. The built-in permanent magnet motor rotor according to claim 1, wherein: Each of the first rotor lamination and the second rotor lamination includes a plurality of laminations having the same shape.

7. The built-in permanent magnet motor rotor according to claim 1 further includes: One or more permanent magnets are housed in permanent magnet slots, and at least one permanent magnet is simultaneously located in the openings of the first rotor lamination and the second rotor lamination.

8. The built-in permanent magnet motor rotor according to claim 7, wherein: The ratio of the overlapping area of ​​the openings of the first rotor lamination and the second rotor lamination to the area of ​​the opening of the first rotor lamination or the second rotor lamination is greater than or equal to 60%.

9. The built-in permanent magnet motor rotor according to claim 8, wherein: The ratio of the overlapping area of ​​the openings of the first rotor lamination and the second rotor lamination to the area of ​​the opening of the first rotor lamination or the second rotor lamination is less than or equal to 98%.

10. The built-in permanent magnet motor rotor according to claim 7 or 8, wherein: The ratio of the cross-sectional area of ​​the permanent magnet to the overlapping area is greater than or equal to 50%.

11. The built-in permanent magnet motor rotor according to claim 1, wherein: The thickness of rotor laminations with small arc radius is greater than that of rotor laminations with large arc radius.

12. The built-in permanent magnet motor rotor according to claim 1, wherein: The radius of the inner hole of the rotor lamination with a small arc radius is greater than the radius of the inscribed circle of the inner hole of the regular polygon of the rotor lamination with a large arc radius.

13. The built-in permanent magnet motor rotor according to claim 12, wherein: The radius of the inner hole of the rotor lamination with a small arc radius is smaller than the radius of the circumcircle of the inner hole of the regular polygon of the rotor lamination with a large arc radius.

14. A permanent magnet motor, comprising: stator; as well as The built-in permanent magnet motor rotor according to claim 1 is disposed in the stator.

15. The permanent magnet motor according to claim 14, wherein: The number of stator slots per pole and per phase of a permanent magnet motor is 1.

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