Motor

Patent metadata

Field	Value
Publication number	US-9973048-B2
Application number	US-201615052285-A
Country	US
Kind code	B2
Filing date	Feb 24, 2016
Priority date	Feb 27, 2015
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

A motor may include a rotor including a shaft; a stator; and a bearing supporting the shaft. The rotor may include a plurality of core pieces on an outer side of the shaft, a plurality of permanent magnets, and a mold resin part between the core pieces. The neighboring core pieces may include a magnet insertion hole provided therebetween. The permanent magnet may include two poles, with poles of neighboring magnets facing each other having identical polarity. The mold resin part may include at least one first guide part disposed closer to one side than the center between neighboring core pieces, and covers at least a portion of a surface on one side of the magnet insertion hole in a circumferential direction, the permanent magnet being in direct indirect contact via resin with the core piece disposed on the other side of the magnet insertion hole.

First claim

What is claimed is:

1. A motor, comprising:
a rotor comprising a shaft having its center on a vertically extended center axis;
a stator which is disposed at a radially outer side of the rotor; and
a bearing which supports the shaft,
wherein the rotor comprises a plurality of core pieces arranged on a radially outer side of the shaft along a circumferential direction, a plurality of permanent magnets to magnetize the core piece part, and a mold resin part made of resin and disposed between the plurality of core pieces,
the neighboring core pieces comprises a magnet insertion hole provided therebetween in a circumferential direction, extended in an axial direction for insertion of the permanent magnet,
the permanent magnet comprises two magnetic poles arranged along a circumferential direction, the magnetic poles of the circumferentially neighboring permanent magnets facing each other having identical polarity,
the mold resin part comprises at least one first guide part provided within the magnet insertion hole, the first guide part disposed closer to one side in a circumferential direction than the center in between the neighboring core pieces, and covers at least a portion of a surface on one side of the magnet insertion hole in a circumferential direction,
the permanent magnet being in direct contact or in indirect contact via resin with the core piece disposed on the other side of the magnet insertion hole in the circumferential direction,
wherein a relationship of L 1 −L 2 <L 3 is satisfied, in which L 1 is a distance between an end portion on the other side of the first guide part and the core piece on the other side of the magnet insertion hole in a circumferential direction, L 2 is a width of the permanent magnet in the circumferential direction, and L 3 is a distance between an end portion on the other side of the first guide part and the core piece on one side of the magnet insertion hole in the circumferential direction.

2. The motor according to claim 1 ,
wherein the plurality of first guide parts is disposed on the same side with respect to the center in between the neighboring core pieces in the circumferential direction.

3. The motor according to claim 1 ,
wherein the first guide part is in contact with the permanent magnet.

4. The motor according to claim 1 ,
wherein at least two first guide parts are provided inside the magnet insertion hole.

5. The motor according to claim 4 ,
wherein at least one first guide part is each provided to a radially inner side than the center of the magnet insertion hole in the circumferential direction, and to a radially outer side than the center of the magnet insertion hole in the circumferential direction.

6. The motor according to claim 5 ,
wherein the shape of a cross section perpendicular to the axial direction of the permanent magnet is quadrangular.

7. The motor according to claim 1 ,
wherein the mold resin part comprises at least one second guide part provided inside the magnet insertion hole, and
the second guide part is disposed closer to one circumferential direction than the center of the magnet insertion hole in the radial direction, and covers at least a portion of a surface on one radial direction of the magnet insertion hole.

8. The motor according to claim 7 ,
wherein the second guide part is disposed at a more radially inner side than the center of the magnet insertion hole in the circumferential direction, and covers at least a portion of a surface on a radially inner side of the magnet insertion hole.

9. The motor according to claim 7 ,
wherein the second guide part is in contact with the permanent magnet.

10. The motor according to claim 7 ,
wherein at least two second guide parts are provided inside the magnet insertion hole.

11. The motor according to claim 10 ,
wherein at least one second guide part is each provided closer to one circumferential direction than the center of the magnet insertion hole in the circumferential direction, and to the other circumferential direction of the magnet insertion hole in the circumferential direction.

12. The motor according to claim 7 ,
wherein at least one of the second guide parts is a rib which protrudes inside the magnet insertion hole.

13. The motor according to claim 1 ,
wherein at least one of the first guide parts is a rib which protrudes inside the magnet insertion hole.

14. The motor according to claim 12 ,
wherein the rib extends in the axial direction, and
the width of the rib increases toward the axially upper side in the protruding direction of the rib.

15. The motor according to claim 12 ,
wherein the rib extends in the axial direction, and
the width of the rib increases toward the axially upper side in a direction perpendicular to the protruding direction of the rib and to the axial direction.

16. The motor according to claim 12 ,
wherein the shape of a cross section perpendicular to the extending direction of the rib is semicircular.

17. The motor according to claim 12 ,
wherein the mold resin part comprises an upper cover part which is disposed at a radially upper side of the core piece part, and
the rib is connected to the cover part.

18. The motor according to claim 13 ,
wherein the rib is disposed at a radially inner side or a radially outer side of a surface adjacent to the magnet insertion hole.

19. The motor according to claim 1 ,
wherein among the corner parts on a radially outer side of the core piece part, the corner parts on an other circumferential side are chamfered.

20. The motor according to claim 1 ,
wherein among the corner parts on a radially outer side of the permanent magnet, the corner parts on one circumferential side are chamfered.

21. The motor according to claim 1 ,
wherein an end portion on a radially inner side of the core piece part is disposed at a radially outer side than an end portion on a radially inner side of the permanent magnet.

22. The motor according to claim 1 ,
wherein the permanent magnet is in indirect contact with the core piece part disposed on an other circumferential side of the magnet insertion hole through the resin.

23. The motor according to claim 1 ,
wherein the permanent magnet is in direct contact with the core piece part disposed on an other circumferential side of the magnet insertion hole.

24. The motor according to claim 1 ,
wherein the core piece parts are separated from each other.

25. The motor according to claim 1 ,
wherein the core piece parts are connected to each other.

Assignees

• Nidec Corp

Inventors

• Kawamoto Tatsuro
• Migita Takayuki
• Atarashi Takao
• Nakahara Yasuaki

Classifications

• H02K1/274

  the rotor consisting of two or more circumferentially positioned magnets · CPC title

• H02K1/272

  the magnetisation axis of the magnets being perpendicular to the rotor axis · CPC title

• H02K2213/03

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

• H02K15/03

  having permanent magnets · CPC title

• H02K1/2773 Primary

  consisting of tangentially magnetized radial magnets · CPC title