Rotating Electric Machine

Patent metadata

Field	Value
Publication number	US-2016149461-A1
Application number	US-201414892426-A
Country	US
Kind code	A1
Filing date	Mar 12, 2014
Priority date	May 20, 2013
Publication date	May 26, 2016
Grant date	—

Abstract

A small and low-price rotating electric machine has a structure where a magnet end surface and a metal tube end are not in contact with each other. The rotating electric machine has a cylindrical stator core, a rotor having a shaft provided on the inner circumferential side of the stator core, a yoke fixed to the shaft, at least one ferrite magnet provided on the outer circumferential surface of the yoke, and a protective cover provided on the outer circumference of the ferrite magnet. The ferrite magnet end surface is projected with respect to an end surface of the yoke, and has a step portion to form a gap between the end surface of the ferrite magnet and a bottom surface of the protective cover.

First claim

1 . A rotating electric machine comprising: a cylindrical stator core; a rotor having a shaft provided on the inner circumferential side of the stator core; a yoke fixed to the shaft; at least one ferrite magnet provided on the outer circumferential surface of the yoke; and a protective cover provided on the outer circumference of the ferrite magnet,
wherein an end surface of the ferrite magnet is projected with respect to an end surface of the yoke, and has a step portion to form a gap between the end surface of the ferrite magnet and a bottom surface of the protective cover.

2 . The rotating electric machine according to claim 1 ,
wherein the stator core is shorter than the ferrite magnet, and wherein the ferrite magnet is projected at the both ends of the stator core.

3 . The rotating electric machine according to claim 1 ,
wherein the protective cover is provided with a concave portion having the step portion to avoid a projection of the ferrite magnet.

4 . The rotating electric machine according to claim 1 , wherein the yoke has a yoke step portion on the outer circumferential side as the step portion, wherein an L-shaped bent portion of the protective cover and the yoke step portion are in contact, and wherein a gap is formed with respect to the projection of the ferrite magnet.

5 . The rotating electric machine according to claim 3 ,
wherein the concave portion of the protective cover has an obtuse bent portion at the beginning of the concave portion, wherein the yoke and the bent portion are in contact, and wherein the bent portion is deformed in a direction from an obtuse angle toward a right angle.

6 . The rotating electric machine according to claim 1 , further comprising an end plate having a step portion for positioning of the ferrite magnet.

7 . The rotating electric machine according to claim 1 , further comprising a second end plate on the end surface of the yoke, wherein a second step portion in contact with an L-shaped bent portion of the protective cover is provided on the outer circumferential side of the second end plate, and wherein a gap is provided with respect to the projection of the ferrite magnet.

Assignees

• Hitachi Automotive Systems Ltd

Inventors

• Kono Yohei
• Wada Hisashi
• Nakatsugawa Junnosuke
• Suzuki Ippei

Classifications

• H02K1/2733 Primary

  Annular magnets · CPC title

• H02K5/128 Primary

  using air-gap sleeves or air-gap discs · CPC title

• H02K1/30

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

• H02K1/278

  Surface mounted magnets; Inset magnets · CPC title