Rotating electric machine

Patent metadata

Field	Value
Publication number	US-12301059-B2
Application number	US-201917429355-A
Country	US
Kind code	B2
Filing date	Mar 28, 2019
Priority date	Mar 28, 2019
Publication date	May 13, 2025
Grant date	May 13, 2025

Abstract

Provided is a rotating electric machine, including: a stator; and a rotor, wherein the rotor includes: a rotor core having a plurality of holes formed so as to be arranged in a circumferential direction of the rotor; and at least one permanent magnet, wherein the number of magnetic poles of the rotor is “p”, wherein the plurality of holes include a first hole into which the permanent magnet is inserted, and a second hole into which the permanent magnet is not inserted, the first hole including p/2 first holes, the second hole including p/2 second holes, wherein the first hole and the second hole are formed so as to be alternately arranged in the circumferential direction, and wherein the second hole includes a first opening portion that opens to the stator side in a radial direction of the rotor.

First claim

The invention claimed is:

1. A rotating electric machine, comprising:
a stator; and
a rotor provided rotatably with respect to the stator,
wherein the rotor includes:
a rotor core having a plurality of holes formed so as to be arranged in a circumferential direction of the rotor; and
at least one permanent magnet, wherein the number of magnetic poles of the rotor is “p” which is an even number of two or more,

wherein the plurality of holes include a first hole into which the permanent magnet is inserted, and a second hole into which the permanent magnet is not inserted, the first hole comprising p/2 first holes, the second hole comprising p/2 second holes,
wherein the first hole and the second hole are formed so as to be alternately arranged in the circumferential direction,
wherein the permanent magnet is magnetized such that magnetic-pole surfaces facing each other in the circumferential direction across the second hole have different poles,
wherein the second hole, when viewed from an axial direction, has an open cross section that includes a first opening at an outer peripheral portion of the rotor to form a gap in the circumferential direction at the outer peripheral portion of the rotor core, and a second opening portion at an inner peripheral portion of the rotor core to form a gap in the circumferential direction at the inner peripheral portion of the rotor core, and
wherein at a portion of the second hole between the first opening portion and the second opening portion, a width of the second hole in a tangential direction along the circumferential direction is increased from the stator side toward the side opposite to the stator in the radial direction.

2. The rotating electric machine according to claim 1 ,
wherein the second hole includes a first portion, and a second portion located on the stator side in the radial direction with respect to the first portion, and
wherein, when a width of the first portion in a tangential direction along the circumferential direction is L1, and a width of the second portion in the tangential direction is L2, a relationship of L1>L2 is satisfied.

3. The rotating electric machine according to claim 2 , wherein the second hole is formed so as to have a width in the tangential direction that monotonically increases as a distance from the stator increases in the radial direction.

4. The rotating electric machine according to claim 1 , wherein, when an opening width of the first opening portion is Lo1, and a maximum value of an interval between the stator and the rotor in the radial direction is Gmmax, a relationship of Lo1>Gmmax is satisfied.

5. The rotating electric machine according to claim 1 ,
wherein the rotor core includes a plurality of core portions each sandwiched by two second holes adjacent to each other in the circumferential direction,
wherein each of the plurality of core portions includes a first core portion located on one magnetic-pole surface side of the permanent magnet, and a second core portion located on the other magnetic-pole surface side of the permanent magnet, and
wherein the rotor core further includes a coupling portion that couples the first core portions of the plurality of core portions to each other.

6. The rotating electric machine according to claim 1 , wherein the first hole includes a third opening portion that opens to the stator side in the radial direction, or a fourth opening portion that opens to a side opposite to the stator in the radial direction.

7. The rotating electric machine according to claim 1 , wherein the width of the second hole in the tangential direction along the circumferential direction is increased in a stepwise manner from the stator side toward the side opposite to the stator in the radial direction.

8. The rotating electric machine according to claim 1 , wherein the second hole is filled with a non-magnetic material.

9. The rotating electric machine according to claim 8 , wherein the non-magnetic material is a resin.

10. A rotating electric machine, comprising:
a stator; and
a rotor provided rotatably with respect to the stator,
wherein the rotor includes:
a rotor core having a plurality of holes formed so as to be arranged in a circumferential direction of the rotor; and
at least one permanent magnet,

wherein the number of magnetic poles of the rotor is “p” which is an even number of two or more,
wherein the plurality of holes include a first hole into which the permanent magnet is inserted, and a second hole into which the permanent magnet is not inserted, the first hole comprising p/2 first holes, the second hole comprising p/2 second holes,
wherein the first hole and the second hole are formed so as to be alternately arranged in the circumferential direction,
wherein the permanent magnet is magnetized such that magnetic-pole surfaces facing each other in the circumferential direction across the second hole have different poles,
wherein the second hole, when viewed from an axial direction, has an open cross section that includes two opening portions respectively located at an inner peripheral portion of the rotor core and an outer peripheral portion of the rotor core to form gaps in the circumferential direction in the inner peripheral portion and the outer peripheral portion of the rotor core, respectively,
wherein the rotor core includes a first rotor core and a second rotor core laminated on each other in an axial direction,
wherein each of the first rotor core and the second rotor core includes a plurality of core portions sandwiched by two second holes adjacent to each other in the circumferential direction,
wherein each of the plurality of core portions includes a first core portion located on one magnetic-pole surface side of the permanent magnet, and a second core portion located on the other magnetic-pole surface side of the permanent magnet,
wherein the first rotor core further includes a first coupling portion that couples the first core portions of the first rotor core to each other, and
wherein the second rotor core further includes a second coupling portion that couples the second core portions of the second rotor core to each other.

11. The rotating electric machine according to claim 10 ,
wherein the second hole includes a first portion, and a second portion located on the stator side in the radial direction with respect to the first portion, and
wherein, when a width of the first portion in a tangential direction along the circumferential direction is L1, and a width of the second portion in the tangential direction is L2, a relationship of L1>L2 is satisfied.

12. The rotating electric machine according to claim 11 , wherein the second hole is formed so as to have a width in the tangential direction that monotonically increases as a distance from the stator increases in the radial direction.

13. The rotating electric machine according to claim 10 , wherein, when an opening width of the first opening portion is Lo1, and a maximum value of an interval between the stator and the rotor in the radial direction is Gmmax, a relationship of Lo1>Gmmax is satisfied.

14. The rotating electric machine according to claim 10 , wherein the first hole includes a third opening portion that opens to the stator side in the radial direction, or a fourth opening portion that opens to a side opposite to the stator in the radial direction.

15. A rotating electric machine, comprising:
a stator; and
a rotor provided rotatably with respect to the stator,
wherein the rotor includes:
a rotor core having a plurality of holes formed so as to be arranged in a circumferential direct

Assignees

• Mitsubishi Electric Corp

Inventors

• Motoyoshi Kenta
• Sasaki Hidenori
• Okazaki Kodai
• Ikeda Hiroko

Classifications

• H02K2201/03

  Machines characterised by aspects of the air-gap between rotor and stator · CPC title

• H02K21/16

  having annular armature cores with salient poles (with homopolar co-operation H02K21/20) · CPC title

• H02K2213/03

  Machines characterised by numerical values, ranges, mathematical expressions or similar information · CPC title

• H02K1/276 Primary

  Magnets embedded in the magnetic core, e.g. interior permanent magnets [IPM] · CPC title

• H02K1/2773 Primary

  consisting of tangentially magnetized radial magnets · CPC title