Permanent magnet embedded-type rotating electric machine and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-2016072348-A1
Application number	US-201514941518-A
Country	US
Kind code	A1
Filing date	Nov 13, 2015
Priority date	Oct 2, 2013
Publication date	Mar 10, 2016
Grant date	—

Abstract

Cracking and flying around of permanent magnets in a permanent magnet embedded-type rotating electric machine is prevented. Thermally hardening FRP is used as a reinforcement sheet, and the reinforcement sheet is wrapped around the periphery of a permanent magnet and caused to adhere to the surface of the permanent magnet by being thermally hardened. Subsequently, the permanent magnet to which the reinforcement sheet is adhering is embedded in magnet embedding holes of the rotor. The surface of the reinforcement sheet after thermal hardening is in a state of not being attached to the inner wall surface of the magnet embedding holes. Consequently, no stress caused by the difference between the linear expansion coefficients of the rotor and permanent magnets acts on the permanent magnets when the temperature of the rotor rises, and cracking of the permanent magnets can thus be prevented.

First claim

What is claimed is:

1 . A permanent magnet embedded-type rotating electric machine, formed by permanent magnets to which reinforcement sheets are adhering being embedded in magnet embedding holes formed in a circumferential direction in a rotor, wherein surfaces of the reinforcement sheets are in a state of not being attached to an inner wall surface of the magnet embedding holes.

2 . The permanent magnet embedded-type rotating electric machine according to claim 1 , formed with one turn or more of the reinforcement sheets adhering to two magnetized surfaces perpendicular to a magnetization direction of the permanent magnets and a non-magnetized surface.

3 . The permanent magnet embedded-type rotating electric machine according to claim 2 , formed with one turn of the reinforcement sheets, wherein end portions of the reinforcement sheets adhering to the two magnetized surfaces jut out slightly and adhere to another non-magnetized surface.

4 . The permanent magnet embedded-type rotating electric machine according to claim 2 , wherein the rotor is such that a center bridge is formed between the magnet embedding holes, the magnet embedding holes communicate with an outer periphery of the rotor on a side opposite to a side of the center bridge, and the permanent magnets are embedded in the magnet embedding holes so that the non-magnetized surface is positioned on the side communicating with the outer periphery of the rotor.

5 . The permanent magnet embedded-type rotating electric machine according to claim 4 , wherein a region on a rotor rotation center axis side of an inner peripheral wall of the magnet embedding holes are inclined in a direction such as to become farther from a rotor rotation center axis as the region moves away from halfway between neighboring poles and nears the center bridge.

6 . The permanent magnet embedded-type rotating electric machine according to claim 5 , wherein the permanent magnets are formed by a non-magnetic and non-conductive spacer being fixed to another non-magnetized surface by adhesion or a fixture.

7 . The permanent magnet embedded-type rotating electric machine according to claim 1 , wherein the rotor is such that a center bridge is formed between the magnet embedding holes, the magnet embedding holes communicate with an outer periphery of the rotor on a side opposite to a side of the center bridge, and a region on a rotor rotation center axis side of an inner peripheral wall of the magnet embedding holes is inclined in a direction such as to become farther from a rotor rotation center axis as the region moves away from halfway between neighboring poles and nears the center bridge.

8 . The permanent magnet embedded-type rotating electric machine according to claim 1 , wherein a number of wrapping turns of the reinforcement sheets is a plural number, a removal process is added to one portion of the reinforcement sheets, and one or more turns of the reinforcement sheets are left with no removal process being added.

9 . The permanent magnet embedded-type rotating electric machine according to claim 8 , wherein an amount of the reinforcement sheets adhering to a magnetized surface perpendicular to a magnetization direction of the permanent magnets is ground away, and an amount of the reinforcement sheets adhering to a non-magnetized surface other than a magnetized surface is left.

10 . The permanent magnet embedded-type rotating electric machine according to claim 8 , formed by a non-magnetic and non-conductive spacer being added to the permanent magnets, and the reinforcement sheets being wrapped around the permanent magnets and spacers.

11 . The permanent magnet embedded-type rotating electric machine according to claim 10 , formed by the spacer being fixed to the permanent magnets by adhesion or a fixture, and the reinforcement sheets being wrapped around.

12 . The permanent magnet embedded-type rotating electric machine according to claim 8 , formed by a non-magnetic and non-conductive spacer being added to permanent magnets to which the reinforcement sheets are adhering.

13 . A method of manufacturing a permanent magnet embedded-type rotating electric machine formed by permanent magnets to which reinforcement sheets are adhering being embedded in magnet embedding holes formed in a rotor, wherein
thermally hardening fiber-reinforced plastic sheets are used as the reinforcement sheets, permanent magnets around which the fiber-reinforced plastic sheets are wrapped is manufactured by one portion of the thermally hardening fiber-reinforced plastic sheets being brought into contact with a surface of the permanent magnets and the one portion being fixed to the surface of the permanent magnets by being thermally hardened by heating, the fiber-reinforced plastic sheets being wrapped around a periphery of the permanent magnets, another portion of the fiber-reinforced plastic sheets being brought into contact, and the other portion being fixed to the surface of the permanent magnets by being thermally hardened by heating, and the permanent magnets to which the reinforcement sheets are adhering is manufactured by thermally hardening the fiber-reinforced plastic sheets by heating the permanent magnets around which the fiber-reinforced plastic sheets are wrapped, thereby causing the fiber-reinforced plastic sheets to adhere to the surface of the permanent magnets.

14 . A method of manufacturing a permanent magnet embedded-type rotating electric machine formed by a permanent magnets to which reinforcement sheets are adhering being embedded in magnet embedding holes formed in a rotor, wherein
thermally hardening fiber-reinforced plastic sheets are used as the reinforcement sheets, and the permanent magnets to which the reinforcement sheets are adhering is manufactured by the thermally hardening fiber-reinforced plastic sheets being thermally hardened and caused to adhere to a surface of the permanent magnets by heating while the fiber-reinforced plastic sheets are pressed against a magnetized surface perpendicular to a magnetization direction of the permanent magnets and one portion of a non-magnetized surface.

15 . A rotor for a permanent magnet embedded-type rotating electric machine, comprising:
a plurality of poles, each pole having a center bridge and an outer peripheral edge portion separated by a space from an outer peripheral edge portion of an adjacent pole, the center bridge and the outer peripheral edge portion defining magnetic embedding openings symmetrically arranged with respect to the center bridge; a permanent magnet in each of the magnetic embedding openings; and at least one reinforcement sheet attached to the permanent magnet.

16 . The rotor of claim 15 , wherein the at least one reinforcement sheet is unattached to an inner wall surface of the magnetic embedding openings.

17 . The rotor of claim 15 , wherein the at least one reinforcement sheet comprises a plurality of reinforcement sheets wound around the permanent magnet.

18 . The rotor of claim 15 , wherein the permanent magnet has two magnetic surfaces opposite each other, and two non-magnetic surfaces opposite each other, and the at least one reinforcement sheet extends along a first one of the two magnetic surfaces, along a first one of the two non-magnetic surfaces, and along a second one of the two magnetic surfaces opposite the first one of the two magnetic surfaces, but does not extend along a second one of the two non-magnetic surfaces opposite the first one of the two non-magnetic surfaces.

19 . The rotor of

Assignees

• Fuji Electric Co Ltd

Inventors

• Mochida Toshiharu
• Sakiyama Takashi
• Shuto Masao
• Sasaki Toshiya
• Nishimura Hirofumi
• Iwamoto Takeshi
• Nakazaki Yuji
• Chikazawa Takasumi
• Kato Keizou

Classifications

• H02K1/30

  using intermediate parts, e.g. spiders · CPC title

• H02K1/276 Primary

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

• H02K15/03

  having permanent magnets · CPC title

• H02K1/02

  characterised by the magnetic material · CPC title