Rotating electric machine

• US 20020195885A1
• Filed: 05/20/2002
• Published: 12/26/2002
• Est. Priority Date: 06/20/2001
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Kikuchi, Toshio, Kaneko, Yutaro, Tsuneyoshi, Takashi, Kitada, Shinichiro
• Granted Patent: US 6,570,277 B2
• Time in Patent Office: Days
• US Class Current: 310/43
• CPC Class Codes: H02K 1/185 to outer stators
• CPC Class Codes: H02K 5/08 Insulating casings
• CPC Class Codes: H02K 5/128 using air-gap sleeves or air-gap discs
• CPC Class Codes: H02K 9/197 in which the rotor or stator space is fluid-tight, e.g. to provide for different cooling media for rotor and stator

Abstract

An annular member 51 is fitted to the outer periphery of the stator cores in a rotating electric machine. The rotating electric machine has a cooling passage 29 in an axial direction between a resin molded section 50 and adjacent stator cores 20. The annular member 51 is formed from a material which has a larger coefficient of linear expansion than the magnetic material comprising the stator cores. At low temperatures, stress resulting from the differential between the coefficient of linear expansion of the stator core and the resin molded section is reduced because an inward compressive force is applied to the stator core by the annular member as a result of the difference in the coefficient of linear expansion.

Claims

1. A rotating electric machine comprising

a rotor;

a circular stator having a plurality of stator cores connected about an periphery of the rotor and an annular member disposed on an outer periphery of the plurality of stator cores;

a case for housing the rotor and the stator;

a resin molded section formed along an inner peripheral face of the stator and covering slot openings between stator cores; and

a cooling passage extending along an axial direction of the rotor and being defined by adjacent stator cores and the resin molded section;

wherein the annular member is formed from a material which has a larger coefficient of linear expansion than a magnetic material comprising the stator cores.

2. The rotation electric machine as defined in claim 1, wherein the coefficient of linear expansion of the material comprising the annular member is greater than the coefficient of linear expansion of a material comprising the resin molded section.

3. The rotating electric machine as defined in claim 1, wherein the case comprises a rubber member which supports an end of the resin molded section.

4. The rotating electric machine as defined in claim 1, wherein the annular member comprises a plurality of radially-laminated annular layers, each annular layer formed from material different from material of the other annular layer.

5. The rotating electric machine as defined in claim 1, wherein the annular member is a member separate from the case.