Rotating electrical machine

Patent metadata

Field	Value
Publication number	US-9935513-B2
Application number	US-201314769851-A
Country	US
Kind code	B2
Filing date	Apr 22, 2013
Priority date	Apr 22, 2013
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

According to an electric motor, a cooling hole is formed outside of a circular arc-like region having an intersection between extension lines from inner side surfaces of adjacent permanent magnets as a center of the circular arc-like region and a distance between the intersection and an intermediate point on the side surface of the permanent magnet as a radius of the circular arc-like region. Thus, heat generation by a magnetic resistance due to the cooling hole is suppressed to improve efficiency.

First claim

The invention claimed is:

1. A rotating electrical machine, comprising:
an annular stator; and
a rotator arranged on an inner side of the annular stator so as to be rotatable,
the rotator comprising:
a rotator core having a plurality of cooling holes formed along a circumferential direction, through which refrigerant passes; and
a plurality of permanent magnets arranged at intervals in an outer circumferential portion of the rotator core, wherein:

the rotator core has magnet accommodating holes for accommodating the plurality of permanent magnets therein, each being formed on both sides of a line extending from a center of each of the plurality of cooling holes in a radial direction as an axis of symmetry to extend in a radially outer direction to be closed in a V-like fashion so that adjacent ones of the plurality of permanent magnets on a radially outer side of the rotator core are separated away from each other across a first bridge portion therebetween;
the each of the plurality of cooling holes is formed outside of a circular arc-like region having an intersection between extension lines from inner side surfaces of the adjacent ones of the plurality of permanent magnets as a center of the circular arc-like region and a distance between the intersection and an intermediate point on the inner side surface of each of the plurality of permanent magnets as a radius of the circular arc-like region; and
a shortest distance between each of the magnet accommodating holes and the each of the plurality of cooling holes is larger than a shortest distance between the adjacent ones of the plurality of permanent magnets in the first bridge portion.

2. A rotating electrical machine according to claim 1 , wherein the rotator core has a concave portion formed in a portion of an outer circumferential surface of the rotator core, which is opposed to the first bridge portion.

3. A rotating electrical machine according to claim 1 , wherein:
a radial width of the each of the plurality of cooling holes is larger than a shortest distance between the plurality of permanent magnets in a second bridge portion between adjacent ones of the magnet accommodating holes of the rotator core on a radially inner side.

4. A rotating electrical machine according to claim 1 , wherein the each of the plurality of cooling holes has curved surfaces each expanding outward, which are formed on both sides in the circumferential direction.

5. A rotating electrical machine according to claim 4 , wherein the each of the plurality of cooling holes comprises an elongated hole extending in the circumferential direction.

6. A rotating electrical machine according to claim 1 , wherein the each of the magnet accommodating holes includes a first hollow portion and a second hollow portion formed on both sides of the each of the magnet accommodating holes, for preventing a leakage flux from the each of the plurality of permanent magnets.

7. A rotating electrical machine according to claim 1 , wherein at least one of the first hollow portion or the second hollow portion has a curved surface expanding outward, the curved surface having a curvature radius of both sides smaller than a curvature radius of an intermediate portion.

8. A rotating electrical machine, comprising:
an annular stator; and
a rotator arranged on an inner side of the annular stator so as to be rotatable,
the rotator comprising:
a rotator core having a plurality of cooling holes formed along a circumferential direction, through which refrigerant passes; and
a plurality of permanent magnets arranged at intervals in an outer circumferential portion of the rotator core, wherein:

the rotator core has magnet accommodating holes for accommodating the plurality of permanent magnets therein, each being formed on both sides of a line extending from a center of each of the plurality of cooling holes in a radial direction as an axis of symmetry to extend in a radially outer direction to be closed in a V-like fashion so that adjacent ones of the plurality of permanent magnets on a radially outer side of the rotator core are separated away from each other across a first bridge portion therebetween; and
the each of the plurality of cooling holes is formed outside of a circular arc-like region having an intersection within said rotator core between extension lines from inner side surfaces of the adjacent ones of the plurality of permanent magnets as a center of the circular arc-like region and a distance between the intersection and an intermediate point on the inner side surface of each of the plurality of permanent magnets as a radius of the circular arc-like region.

9. A rotating electrical machine, comprising:
an annular stator; and
a rotator arranged on an inner side of the annular stator so as to be rotatable,
the rotator comprising:
a rotator core having a plurality of cooling holes formed along a circumferential direction, through which refrigerant passes; and
a plurality of permanent magnets arranged at intervals in an outer circumferential portion of the rotator core, wherein:

the rotator core has magnet accommodating holes for accommodating the plurality of permanent magnets therein, each being formed on both sides of a line extending from a center of each of the plurality of cooling holes in a radial direction as an axis of symmetry to extend in a radially outer direction to be closed in a V-like fashion so that adjacent ones of the plurality of permanent magnets on a radially outer side of the rotator core are separated away from each other across a first bridge portion therebetween; and
the each of the plurality of cooling holes is formed outside of a circular arc-like region having an intersection between extension lines from inner side surfaces of the adjacent ones of the plurality of permanent magnets as a center of the circular arc-like region and a distance between the intersection and an intermediate point on the inner side surface of each of the plurality of permanent magnets as a radius of the circular arc-like region, wherein said radius is smaller than a distance along said axis of symmetry between the each of the plurality of cooling holes and an outer peripheral surface of said rotator core.

Assignees

• Mitsubishi Electric Corp

Inventors

• Yokota Hirohisa
• Sasai Takuma
• Hazeyama Moriyuki
• Kayano Shinsuke

Classifications

• H02K1/2766

  having a flux concentration effect · CPC title

• H02K1/32 Primary

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