Rotary electric machine

• US 10,404,139 B2
• Filed: 05/27/2014
• Issued: 09/03/2019
• Est. Priority Date: 05/27/2014
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Horii, Masaki, Higashino, Hiroyuki
• Primary Examiner(s): Phillips, Forrest M
• Application Number:
  US15/304,592
• Publication Number:
  US 20170047822A1
• Time in Patent Office: 1,925 Days
• Field of Search: 310 54
• CPC Class Codes: H02K 1/12 Stationary parts of the magnetic circuit
• CPC Class Codes: H02K 3/24 with channels or ducts for cooling medium between the conductors
• CPC Class Codes: H02K 5/203 specially adapted for liquids, e.g. cooling jackets
• CPC Class Codes: H02K 9/19 for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil

Abstract

A rotary electric machine includes: an annular cooling oil channel that is configured inside an externally mounted frame so as to face axially toward coils that are arranged in an annular shape and such that a surface that faces the coils is made into an opening; an oil pump; a nozzle that sprays cooling oil that is conveyed under pressure from the oil pump into the cooling oil channel from above; and a plurality of oil flow direction changing projections that are respectively disposed inside the cooling oil channel and are arranged circumferentially so as to face gaps between the coils and such that cooling oil receiving surfaces face upstream in a direction of flow of the cooling oil so as to change the cooling oil that flows through the cooling oil channel to an axial flow so as to be supplied to the gaps between the coils.

Claims

1. A rotary electric machine comprising:

an externally mounted frame;

a rotor that is rotatably disposed inside said externally mounted frame such that an axial direction of a shaft is horizontal;

a stator comprising;

a stator core that is annular and disposed coaxially so as to surround said rotor and that is held by said externally mounted frame, and

a plurality of coils that are mounted to said stator core so as to be arranged in an annular shape;

a cooling oil channel that is annular and configured inside said externally mounted frame so as to face axially toward said plurality of coils that are arranged in the annular shape and such that a surface that faces said plurality of coils is made into an opening said cooling oil channel being axially separated from said stator and opening to an atmosphere;

an oil pump;

a nozzle that sprays cooling oil that is conveyed under pressure from said oil pump into said cooling oil channel from above; and

a plurality of oil flow direction changing projections that are discretely disposed inside said cooling oil channel,

wherein each of said plurality of oil flow direction changing projections is circumferentially arranged so as to face a gap between adjacent coils, respectively, among said plurality of coils, and has a cooling oil receiving surface,

said cooling oil receiving surface of each of said plurality of oil flow direction changing projections faces upstream with respect to a direction of a flow of said cooling oil so as to change said flow of said cooling oil that flows through said cooling oil channel to an axial flow so as to be supplied to said gap between said adjacent coils, respectively.

2. The rotary electric machine according to claim 1, wherein said cooling oil receiving surface of each of said plurality of oil flow direction changing projections is formed into a concave surface that is convex downstream in said direction of flow of said cooling oil.

3. The rotary electric machine according to claim 1, wherein said cooling oil channel is disposed only at a first axial end of said stator.

4. The rotary electric machine according to claim 1, wherein said cooling oil channel comprises a plurality of cooling oil channels disposed at two axial ends of said stator.

5. The rotary electric machine according to claim 4, wherein said plurality of oil flow direction changing projections are disposed in each of said plurality of cooling oil channels that are disposed at said two axial ends of said stator such that circumferential positions thereof are aligned so as to supply said cooling oil to identical gaps between said adjacent coils from said two axial ends.

6. The rotary electric machine according to claim 4, wherein said plurality of oil flow direction changing projections are disposed in each of said plurality of cooling oil channels that are disposed at said two axial ends of said stator such that circumferential positions thereof alternate so as to supply said cooling oil to alternate gaps between said adjacent coils.

7. The rotary electric machine according to claim 1, wherein said cooling oil channel is formed on an inner wall surface of said externally mounted frame.

8. The rotary electric machine according to claim 1, further comprising a coil end cover that is mounted to said externally mounted frame, and that is disposed so as to cover said plurality of coils that are arranged in the annular shape, said coil end cover constituting said cooling oil channel.

9. The rotary electric machine according to claim 1, wherein said plurality of coils are concentrated winding coils.

10. The rotary electric machine according to claim 1, wherein said plurality of coils are distributed winding coils.