Motor, rotor, compressor, and refrigeration and air conditioning apparatus

Patent metadata

Field	Value
Publication number	US-11018535-B2
Application number	US-201515758024-A
Country	US
Kind code	B2
Filing date	Nov 2, 2015
Priority date	Nov 2, 2015
Publication date	May 25, 2021
Grant date	May 25, 2021

Abstract

A motor includes a stator and a rotor provided inside the stator. The rotor includes a rotor core having a magnet insertion hole and two permanent magnets disposed in the magnet insertion hole. The rotor core has a first magnet holding portion disposed between the two permanent magnets and holding the two permanent magnets, an opening disposed on an inner side of the first magnet holding portion in a radial direction of the rotor core, and a center hole disposed at a center of the rotor core in the radial direction. A distance from the opening to the magnet insertion hole is shorter than a distance from the opening to the center hole.

First claim

What is claimed is:

1. A motor comprising a stator and a rotor provided inside the stator,
the rotor comprising:
a rotor core having two a-magnet insertion hole holes, and
two permanent magnets disposed in each magnet insertion hole,
wherein the rotor core has:
a first magnet holding portion disposed between the two permanent magnets and holding the two permanent magnets in each magnet insertion hole;
two openings each of which is disposed on an inner side of the first magnet holding portion in a radial direction of the rotor core, the opening penetrating the rotor core in an axial direction of the rotor core, and
a center hole disposed at a center of the rotor core in the radial direction,
wherein a distance from each opening to the magnet insertion hole is shorter than or equal to 3 mm, and is shorter than a distance from the opening to the center hole;
wherein the two openings form a continuous hole in a circumferential direction of the rotor core.

2. The motor according to claim 1 , wherein the rotor core has two second magnet holding portions disposed at the both end portions of the magnet insertion hole in the circumferential direction, each of the two second magnet holding portions holding a corresponding one of the two permanent magnets.

3. The motor according to claim 1 , wherein the rotor core has a plurality of electromagnetic steel sheets stacked in an axial direction, and
wherein the distance from the opening to the magnet insertion hole is greater than or equal to a thickness of one electromagnetic steel sheet.

4. The motor according to claim 1 , wherein the opening crosses a line connecting a point shifted in a direction of a width of one permanent magnet of the two permanent magnets by 5% of the width from an end portion of the one permanent magnet on the first magnet holding portion side and the center of the rotor core in the radial direction, and
wherein the opening also crosses a line connecting a point shifted in a direction of a width of the other permanent magnet by 5% of the width from an end portion of the other permanent magnet on the first magnet holding portion side and the center of the rotor core in the radial direction.

5. The motor according to claim 1 , wherein the magnet insertion hole extends straight.

6. The motor according to claim 1 , wherein each of the two permanent magnets is a rare earth magnet containing neodymium (Nd), iron (Fe) and boron (B) as principal components, and exhibits a residual magnetic flux density in a range from 1.27 T to 1.42 T at 20° C. and a coercivity in a range from 1671 kA/m to 1922 kA/m at 20° C.

7. The motor according to claim 1 , wherein the opening has a circular shape.

8. The motor according to claim 1 , wherein the rotor core further has another opening disposed between the opening and the center hole.

9. The motor according to claim 1 , wherein the first magnet holding portion protrudes in the radial direction of the rotor core from an inner surface of the magnet insertion hole.

10. The motor according to claim 1 , wherein the first magnet holding portion is disposed on an inner side of the magnet insertion hole in the radial direction of the rotor core.

11. The motor according to claim 1 , wherein the magnet insertion hole has a V-shape such that a center portion in a circumferential direction of the rotor core protrudes inward in the radial direction with respect to both end portions in the circumferential direction, and
wherein the opening is disposed at a position facing an apex of the V-shape.

12. The motor according to claim 11 , wherein the opening is disposed on a straight line connecting a center of the magnet insertion hole in the circumferential direction and the center of the rotor core.

13. A rotor comprising:
a rotor core having two a-magnet insertion hole holes, and
two permanent magnets disposed in each the magnet insertion hole,
wherein the rotor core has:
a first magnet holding portion disposed between the two permanent magnets and holding the two permanent magnets in each magnet insertion hole;
two openings each of which is an opening disposed on an inner side of the first magnet holding portion in a radial direction of the rotor core, the opening penetrating the rotor core in an axial direction of the rotor core, and
a center hole disposed at a center of the rotor core in the radial direction,
wherein a distance from each the opening to the magnet insertion hole is shorter than or equal to 3 mm, and is shorter than a distance from the opening to the center hole;
wherein the two openings form a continuous hole in a circumferential direction of the rotor core.

14. A compressor comprising a motor and a compression mechanism driven by the motor,
the motor comprising a stator and a rotor provided inside the stator,
the rotor comprising:
a rotor core having two a-magnet insertion hole holes, and
two permanent magnets disposed in each the magnet insertion hole,
wherein the rotor core has:
a first magnet holding portion disposed between the two permanent magnets and holding the two permanent magnets in each magnet insertion hole;
two openings each of which is disposed on an inner side of the first magnet holding portion in a radial direction of the rotor core, the opening penetrating the rotor core in an axial direction of the rotor core, and
a center hole disposed at a center of the rotor core in the radial direction,
wherein a distance from each opening to the magnet insertion hole is shorter than or equal to 3 mm, and is shorter than a distance from the opening to the center hole;
wherein the two openings form a continuous hole in a circumferential direction of the rotor core.

15. A refrigeration and air conditioning apparatus comprising a compressor, a condenser, a decompression device and an evaporator,
the compressor comprising a motor and a compression mechanism driven by the motor,
the motor comprising a stator and a rotor provided inside the stator,
the rotor comprising:
a rotor core having two magnet insertion holes, and
two permanent magnets disposed in each magnet insertion hole,
wherein the rotor core has:
a first magnet holding portion disposed between the two permanent magnets and holding the two permanent magnets in each magnet insertion hole;
two openings each of which is an disposed on an inner side of the first magnet holding portion in a radial direction of the rotor core, the opening penetrating the rotor core in an axial direction of the rotor core, and
a center hole disposed at a center of the rotor core in the radial direction,
wherein a distance from each the opening to the magnet insertion hole is shorter than or equal to 3 mm, and is shorter than a distance from the opening to the center hole;
wherein the two openings form a continuous hole in a circumferential direction of the rotor core.

Assignees

• Mitsubishi Electric Corp

Inventors

• Nigo Masahiro
• Hirosawa Yuji
• Kijima Ryukichi

Classifications

• H02K2213/03

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

• H02K2201/03

  Machines characterised by aspects of the air-gap between rotor and stator · CPC title

• H02K21/14

  with magnets rotating within the armatures · CPC title

• H02K1/28

  Means for mounting or fastening rotating magnetic parts on to, or to, the rotor structures · CPC title

• H02K1/276 Primary

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