Permanent magnet electric rotating machine and electromotive vehicle using permanent magnet electric rotating machine

• US 20030102757A1
• Filed: 01/09/2003
• Published: 06/05/2003
• Est. Priority Date: 10/18/1996
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Shibukawa, Suetaro, Oda, Keiji, Matsunobu, Yutaka, Kawamata, Shouichi, Koizumi, Osamu, Tajima, Fumio
• Granted Patent: US 6,822,360 B2
• Time in Patent Office: Days
• US Class Current: 310/156.57
• CPC Class Codes: H02K 1/276 Magnets embedded in the magnetic core, e.g. interior permanent magnets [IPM]
• CPC Class Codes: H02K 29/03 with a magnetic circuit specially adapted for avoiding torque ripples or self-starting problems

Abstract

A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnetic pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.

Claims

1. A permanent magnet electric rotating machine comprising:

a stator; and

a rotor arranged opposite said stator with a rotation air gap;

said rotor having plural permanent magnet insertion holes arranged circumferentially in a ring-shaped arrangement, permanent magnets embedded in said plural permanent magnet insertion holes, and auxiliary magnetic pole portions provided between two adjacent plural permanent magnets, wherein

a magnetic air gap is provided in both sides of a peripheral direction of said plural permanent magnets,

thereby a change in a magnetic flux density between said plural permanent magnets and said auxiliary magnetic pole portions is formed smoothly and a cogging torque is restrained.

3. A permanent magnet electric rotating machine according to claim 1, wherein a non-magnetic material is provided in said magnetic air gap.

5. An electromotive vehicle comprising a permanent magnet electric rotating machine according to claim 1.

7. An electromotive vehicle comprising a permanent magnet electric rotating machine according to claim 3.

9. A permanent magnet electric rotating machine according to claim 1, wherein each of said plural permanent magnets extends substantially the entire axial length of said rotor.

11. An electromotive vehicle comprising a drive device, wherein said drive device includes the permanent magnet electric rotating machine according to claim 1.

13. An electromotive vehicle comprising a drive device, wherein said drive device includes the permanent magnet electric rotating machine according to claim 3.

15. An electromotive vehicle comprising a drive device, wherein said drive device includes the permanent magnet electric rotating machine according to claim 5.

17. An electromotive vehicle comprising a drive device, wherein said drive device includes the permanent magnet electric rotating machine according to claim 7.

19. An electromotive vehicle comprising a drive device, wherein said drive device includes the permanent magnet electric rotating machine according to claim 9.

2. A permanent magnet electric rotating machine comprising:

a stator; and

a rotor arranged opposite said stator with a rotation air gap;

said rotor having plural permanent magnet insertion holes arranged circumferentially in a ring-shaped arrangement, permanent magnets embedded in said plural permanent magnet insertion holes, auxiliary magnetic pole portions provided between two adjacent plural permanent magnets, and magnetic pole piece portions arranged between said plural permanent magnets and said stator, wherein

a magnetic air gap is provided between said auxiliary magnetic pole portions and said magnetic pole piece portions,

thereby a change in a magnetic flux density between said plural permanent magnets and said auxiliary magnetic pole portion is formed smoothly and a cogging torque is restrained.

4. A permanent magnet electric rotating machine according to claim 2, wherein a non-magnetic material is provided in said magnetic air gap.

6. An electromotive vehicle comprising a permanent magnet electric rotating machine according to claim 2.

8. An electromotive vehicle comprising a permanent magnet electric rotating machine according to claim 4.

10. A permanent magnet electric rotating machine according to claim 2, wherein each of said plural permanent magnets extends substantially the entire axial length of said rotor.

12. An electromotive vehicle comprising a drive device, wherein said drive device includes the permanent magnet electric rotating machine according to claim 2.

14. An electromotive vehicle comprising a drive device, wherein said drive device includes the permanent magnet electric rotating machine according to claim 4.

16. An electromotive vehicle comprising a drive device, wherein said drive device includes the permanent magnet electric rotating machine according to claim 6.

18. An electromotive vehicle comprising a drive device, wherein said drive device includes the permanent magnet electric rotating machine according to claim 8.

20. An electromotive vehicle comprising a drive device, wherein said drive device includes the permanent magnet electric rotating machine according to claim 10.