Rotor, electric motor, compressor, and blower

Patent metadata

Field	Value
Publication number	US-10348145-B2
Application number	US-201415307097-A
Country	US
Kind code	B2
Filing date	Jul 1, 2014
Priority date	Jul 1, 2014
Publication date	Jul 9, 2019
Grant date	Jul 9, 2019

Abstract

A rotor is connected to a shaft member and rotates about a central axis. The rotor includes a shaft hole having at least part of the shaft member disposed therein; and flow paths disposed around the shaft member and penetrating the rotor in a direction parallel with the central axis. Each flow path has a first surface facing outward in the radial direction; a second surface disposed outward of the first surface in the radial direction and facing the first surface; a third surface connecting the first and second surfaces at one end in a rotational direction about the central axis; a fourth surface connecting the first and second surfaces at the other end in the rotational direction. The condition C<D is satisfied, where C is the distance between both ends of the first surface, and D is the distance between both ends of the second surface.

First claim

The invention claimed is:

1. A rotor that is connected to a shaft member, rotates about a central axis, and is used for an electric motor, the rotor comprising:
a tubular member having a shaft hole in which at least a part of the shaft member is arranged to rotate about the central axis; and
a plurality of flow paths positioned around the shaft member and penetrating the rotor in a direction parallel with the central axis, wherein
each of the flow paths has an inner surface including:
a first surface that is a portion of an outer surface of the shaft member;
a second surface positioned outwardly from the first surface in a radial direction and facing the first surface with a clearance between the first surface and the second surface, the second surface being a flat surface;
a third surface connecting one end of the first surface and one end of the second surface in a rotational direction about the central axis; and
a fourth surface connecting another end of the first surface and another end of the second surface in the rotational direction,

each of the flow paths includes:
a first corner connecting the first surface and the third surface;
a second corner connecting the first surface and the fourth surface;
a third corner connecting the second surface and the third surface; and
a fourth corner connecting the second surface and the fourth surface,

the shaft hole has an inner surface including: a connection region connected to the outer surface of the shaft member; and a non-connection region that includes the second surface, the third surface and the fourth surface,
a condition C<D is satisfied, where a distance from the one end of the first surface to the another end of the first surface is C, and a distance from the one end of the second surface to the another end of the second surface is D,
the first corner includes a curved surface extending from a border of the connection region of the tubular member toward the third surface of the non-connection region, and
the second corner includes a curved surface extending from the border of the connection region of the tubular member toward the fourth surface of the non-connection region.

2. The rotor according to claim 1 , wherein a condition L<C is satisfied, where a distance from the first surface to the second surface in the radial direction is L.

3. The rotor according to claim 1 , wherein a condition A≥B is satisfied, where a distance from the third corner of a first flow path to the fourth corner of a second flow path is A, the first flow path being one of the flow paths, the second flow path being another of the flow paths and being adjacent to the first flow path, and a distance from the first corner of the first flow path to the second corner of the second flow path is B.

4. The rotor according to claim 1 , wherein, on a plane orthogonal to the central axis, a first imaginary line connecting the third corner and the central axis coincides with the third surface, and a second imaginary line connecting the fourth corner and the central axis coincides with the fourth surface.

5. The rotor according to claim 1 , wherein
the tubular member is a rotor core positioned around the shaft member and connected to the outer surface of the shaft member, and
the rotor further comprises a squirrel-cage conductor comprising:
a nonmagnetic and conductive rotor bar located in a slot of the rotor core; and
an end ring connected to the rotor bar.

6. The rotor according to claim 1 , wherein the electric motor is a single-phase induction motor.

7. The rotor according to claim 1 wherein the rotor is rotated by a two-pole rotating magnetic field generated by a stator of the electric motor.

8. An electric motor comprising:
a stator that generates a rotating magnetic field; and
a rotor according to claim 1 that is rotated by the rotating magnetic field of the stator.

9. A compressor comprising the electric motor according to claim 8 .

10. A blower comprising the electric motor according to claim 8 .

11. A rotor that is connected to a shaft member, rotates about a central axis, and is used for an electric motor, the rotor comprising:
a tubular member having a shaft hole coaxial with the central axis, at least a part of the shaft member being arranged to rotate about the central axis; and
a plurality of flow paths positioned between the shaft member and the tubular member and extending in a direction parallel with the central axis and penetrating the rotor, wherein
each of the flow paths has an inner surface including:
a first surface that is a portion of an outer surface of the shaft member;
a second surface positioned outwardly from the first surface in the radial direction and facing the first surface with a clearance between the first surface and the second surface;
a third surface connecting one end of the first surface and one end of the second surface in a rotational direction about the central axis; and
a fourth surface connecting another end of the first surface and another end of the second surface in the rotational direction,

each of the flow paths includes:
a first corner connecting the first surface and the third surface;
a second corner connecting the first surface and the fourth surface;
a third corner connecting the second surface and the third surface; and
a fourth corner connecting the second surface and the fourth surface,

the shaft hole has an inner surface including a connection region connected to the outer surface of the shaft member and a non-connection region that includes the second surface, the third surface, and the fourth surface,
a condition C<D is satisfied, where a distance from the one end of the first surface to the another end of the first surface is C, and a distance from the one end of the second surface to the another end of the second surface is D,
the first corner extends from a border of the connection region of the tubular member toward the third surface of the non-connection region,
the second corner extends from the border of the connection region of the tubular member toward the fourth surface of the non-connection region, and
on a plane orthogonal to the central axis, a first imaginary line connecting the third corner and the central axis coincides with the third surface, and a second imaginary line connecting the fourth corner and the central axis coincides with the fourth surface.

12. The rotor according to claim 11 , wherein the second surface includes a curved surface recessed outward in the radial direction.

13. The rotor according to claim 11 , wherein the second surface includes a curved surface having a center on the central axis.

14. The rotor according to claim 11 , wherein, on the plane orthogonal to the central axis, a distance from the one end of the first surface to the another end of the first surface is determined such that a condition is satisfied where the first corner and the second corner are located between the first imaginary line and the second imaginary line.

15. The rotor according to claim 11 , wherein each of the first corner and the second corner includes a curved surface.

16. The rotor according to claim 11 , wherein a condition L<C is satisfied, where a distance from the first surface to the second surface in the radial direction is L.

17. The rotor according to claim 11 , wherein, a condition A≥B is satisfied, where a distance from the third corner of a first flow path to the fourth corner of a second flow path is A, the first flow path being one of the flow paths, the second flow path being another of the flow paths an

Assignees

• Mitsubishi Electric Corp

Inventors

• Yabe Koji
• Baba Kazuhiko
• Tsutsumi Takahiro

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

• H02K17/04

  for single phase current · CPC title

• H02K17/16

  having rotors with internally short-circuited windings, e.g. cage rotors · CPC title

• H02K2213/03

  Machines characterised by numerical values, ranges, mathematical expressions or similar information · CPC title