Rotor of rotary electric machine and method for cooling rotary electric machine

Patent metadata

Field	Value
Publication number	US-11056941-B2
Application number	US-201816050204-A
Country	US
Kind code	B2
Filing date	Jul 31, 2018
Priority date	Sep 4, 2017
Publication date	Jul 6, 2021
Grant date	Jul 6, 2021

Abstract

A rotor of the rotary electric machine includes a rotor core, and a plurality of permanent magnets disposed in an inner part or an outer circumferential surface of the rotor core in a circumferential direction. In the rotor core, one or more first flow passages through which a cooling liquid flows, the one or more first flow passages extending in an axial direction and communicating with the outside of the rotor, and one or more second flow passages extending radially outward from the first flow passage and having closed distal ends, are formed.

First claim

The invention claimed is:

1. A rotor of a rotary electric machine comprising:
a rotor core; and
a plurality of permanent magnets disposed in an inner part or an outer circumferential surface of the rotor core in a circumferential direction,
wherein, in the rotor core:
one or more first flow passages through which a cooling liquid flows, the one or more first flow passages extending in an axial direction and communicating with the outside of the rotor are formed; and
one or more second flow passages extending radially outward from the one or more first flow passages and having closed distal ends are formed.

2. The rotor of the rotary electric machine according to claim 1 , wherein the one or more first flow passages are formed on a radially more inward side than the plurality of permanent magnets, and
the distal ends of the one or more second flow passages are located at a position where the plurality of permanent magnets are able to magnetically attract foreign matter including a magnetic material reaching the distal ends of the one or more second flow passages.

3. The rotor of the rotary electric machine according to claim 1 , wherein the one or more first flow passages have an inlet port for the cooling liquid, and
at least one of the one or more second flow passages extends from the same axial position as the inlet port of the one or more first flow passages.

4. The rotor of the rotary electric machine according to claim 1 , wherein the rotor core is a laminate in which a plurality of steel plates are laminated in the axial direction, and
a longitudinal direction of the one or more first flow passages is parallel to the axial direction.

5. The rotor of the rotary electric machine according to claim 1 , wherein a plurality of second flow passages are connected to each of the one or more first flow passages at intervals in the axial direction.

6. A method for cooling a rotary electric machine including a rotor, a stator arranged concentrically with the rotor, and a rotary shaft fixed to a center of the rotor and rotating together with the rotor,
wherein the rotor has a rotor core, and a plurality of permanent magnets arranged in an inner part or an outer circumferential surface of the rotor core in a circumferential direction,
in the rotor core:
one or more first flow passages through which a cooling liquid flows, the one or more first flow passages extending in an axial direction and communicating with the outside of the rotor are formed; and
one or more second flow passages extending radially outward from the one or more first flow passages and having closed distal ends are formed, and
the rotary electric machine is cooled by supplying the cooling liquid, which has a specific gravity smaller than foreign matter expected to be mixed into the cooling liquid, to the one or more first flow passages.

Assignees

• Toyota Motor Co Ltd

Inventors

• Matsumoto Takashi

Classifications

• H02K9/19

  for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil · CPC title

• H02K1/32 Primary

  with channels or ducts for flow of cooling medium · CPC title

• H02K1/276

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

• H02K9/26

  Structural association of machines with devices for cleaning or drying cooling medium, e.g. with filters · CPC title