Electric motor and air conditioner

Patent metadata

Field	Value
Publication number	US-10855126-B2
Application number	US-201515758481-A
Country	US
Kind code	B2
Filing date	Nov 18, 2015
Priority date	Nov 18, 2015
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

An electric motor includes a stator and a consequent-pole-type rotor including an annular rotor core disposed on an inner side of the stator and a plurality of permanent magnets disposed inside the rotor core and arrayed in a circumferential direction of the rotor core. The rotor core includes at least one slit provided inside the rotor core and disposed on an outer side of each of the permanent magnets in a radial direction of the rotor core, and at least one slit provided on an outer circumferential surface of the rotor core and disposed between the permanent magnets adjacent to each other.

First claim

The invention claimed is:

1. An electric motor comprising:
an annular stator; and
a consequent-pole-type rotor comprising:
an annular rotor core disposed on an inner side of the annular stator, and
a plurality of permanent magnets disposed inside the annular rotor core and arrayed in a circumferential direction of the annular rotor core, wherein

the annular rotor core has:
at least one first slit provided inside the annular rotor core, the at least one first slit being disposed on an outer side of each of the permanent magnets in a radial direction of the annular rotor core, and
at least one second slit provided on an outer circumferential surface of the annular rotor core, the at least one second slit being disposed between closest neighboring permanent magnets among the permanent magnets, and wherein
a width of the at least one second slit in a direction orthogonal to the radial direction of the rotor core being larger than a width of the at least one first slit in the direction orthogonal to the radial direction.

2. The electric motor according to claim 1 , wherein a total area of the at least one second slit is larger than a total area of the at least one first slit.

3. The electric motor according to claim 2 , wherein a number of the at least one second slit is larger than a number of the at least one first slit.

4. The electric motor according to claim 2 , wherein a width of the at least one second slit in the radial direction of the rotor core is larger than a width of the at least one first slit in the radial direction.

5. The electric motor according to claim 1 , wherein a first magnetic pole formed by the permanent magnet and a second magnetic pole formed between the adjacent permanent magnets are alternately arrayed on the outer circumferential surface of the rotor core, and an outer diameter of the rotor core at a pole center of the first magnetic pole is equal to an outer diameter of the rotor core at a pole center of the second magnetic pole.

6. The electric motor according to claim 1 , wherein
a first resin section is provided in the at least one first slit, and
a second resin section is provided in the at least one second slit.

7. The electric motor according to claim 1 , wherein
the at least one first slit includes no opening section on the outer circumferential surface of the rotor core, and
the at least one second slit is opened to the outer circumferential surface of the rotor core.

8. An air conditioner comprising the electric motor according to claim 1 .

9. An electric motor comprising:
an annular stator; and
a consequent-pole-type rotor comprising:
an annular rotor core disposed on an inner side of the annular stator, and
a plurality of permanent magnets disposed inside the annular rotor core and arrayed in a circumferential direction of the annular rotor core, wherein

the annular rotor core has:
at least one first slit provided inside the annular rotor core, the at least one first slit being disposed on an outer side of each of the permanent magnets in a radial direction of the annular rotor core, and
at least one second slit provided on an outer circumferential surface of the annular rotor core, the at least one second slit being disposed between closest neighboring permanent magnets among the permanent magnets, and wherein

the at least one first slit including no opening section on the outer circumferential surface of the rotor core,
the at least one second slit being opened to the outer circumferential surface of the rotor core,
flux barrier sections are provided at opposite end portions of the permanent magnet, and
an end portion of each of the flux barrier sections is parallel to the second slit adjacent to the end portion; and wherein
a width of the at least one second slit in a direction orthogonal to the radial direction of the rotor core is larger than a width of the at least one first slit in the direction orthogonal to the radial direction.

10. The electric motor according to claim 9 , wherein a total area of the at least one second slit is larger than a total area of the at least one first slit.

11. The electric motor according to claim 10 , wherein a number of the at least one second slit is larger than a number of the at least one first slit.

12. The electric motor according to claim 10 , wherein a width of the at least one second slit in the radial direction of the rotor core is larger than a width of the at least one first slit in the radial direction.

13. The electric motor according to claim 9 , wherein a first magnetic pole formed by the permanent magnet and a second magnetic pole formed between the adjacent permanent magnets are alternately arrayed on the outer circumferential surface of the rotor core, and an outer diameter of the rotor core at a pole center of the first magnetic pole is equal to an outer diameter of the rotor core at a pole center of the second magnetic pole.

14. The electric motor according to claim 9 , wherein
a first resin section is provided in the at least one first slit, and
a second resin section is provided in the at least one second slit.

15. An air conditioner comprising the electric motor according to claim 9 .

Assignees

• Mitsubishi Electric Corp

Inventors

• Oikawa Tomoaki
• Yamamoto Mineo
• Ishii Hiroyuki
• Aso Hiroki
• Oya Junichiro
• Urabe Yuto
• Shimokawa Takaya
• Yabe Koji

Classifications

• H02K21/16

  having annular armature cores with salient poles (with homopolar co-operation H02K21/20) · CPC title

• H02K1/27

  Rotor cores with permanent magnets · CPC title

• H02K2213/03

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

• H02K1/276 Primary

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

• H02K1/2753 Primary

  the rotor consisting of magnets or groups of magnets arranged with alternating polarity · CPC title