PERMANENT MAGNET BURIED TYPE ELECTRIC MOTOR AND COMPRESSOR

• US 20150318764A1
• Filed: 12/21/2012
• Published: 11/05/2015
• Est. Priority Date: 12/21/2012
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: BABA, Kazuhiko, NIGO, Masahiro, TSUCHIDA, Kazuchika
• Granted Patent: US 9,899,897 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F04C 18/356 with vanes reciprocating with respect to the outer member
• CPC Class Codes: F04C 2210/263 HFO1234YF
• CPC Class Codes: F04C 23/008 Hermetic pumps
• CPC Class Codes: F04C 29/0085 Prime movers
• CPC Class Codes: F04D 25/06 the pump being electrically driven F04D25/08 takes precedence
• CPC Class Codes: H02K 1/2706 Inner rotors
• CPC Class Codes: H02K 1/2766 having a flux concentration effect
• CPC Class Codes: H02K 1/32 with channels or ducts for flow of cooling medium
• CPC Class Codes: H02K 2201/03 Machines characterised by aspects of the air-gap between rotor and stator
• CPC Class Codes: H02K 7/14 Structural association with mechanical loads, e.g. with hand-held machine tools or fans with fan or impeller for cooling the machine H02K9/06
• CPC Class Codes: H02K 9/02 by ambient air flowing through the machine
• CPC Class Codes: H02K 9/19 for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil

Abstract

A permanent magnet buried type electric motor includes a rotator having a rotator core and a stator. The rotator core includes: a plurality of magnet accommodating holes formed as many as the number of poles; a plurality of permanent magnets; air holes through which a coolant and a refrigerant oil pass; and a fastening hole. The magnet accommodating hole is formed into a shape that projects toward a radially inner side and is recessed toward a radially outer side. The air hole portions and the fastening holes are arranged so as to be alternately positioned. The air hole portion is formed into such a shape that includes a portion extending in an arc shape along an outer peripheral surface of a rotary shaft in a circumferential direction of the rotator core so that an area of the air hole portion is larger than an area of the fastening hole.

Claims

1. A permanent magnet buried type electric motor, comprising:

a rotator including a rotator core including a plurality of laminated constituent sheets; and

a stator arranged so as to surround the rotator,

the rotator core comprising;

a plurality of magnet accommodating holes formed as many as a number of poles along a circumferential direction;

a plurality of permanent magnets accommodated in the plurality of magnet accommodating holes;

air hole portions serving as paths for allowing a coolant and a refrigerant oil to pass therethrough;

fastening holes for fastening the plurality of laminated constituent sheets,

each of the plurality of magnet accommodating holes being formed into a shape that projects toward a radially inner side of the rotator core and is recessed toward a radially outer side thereof,

the plurality of air hole portions and the plurality of fastening holes being arranged in the circumferential direction of the rotator core so as to be alternately positioned,

the air hole portion being formed into such a shape that includes a portion extending in an arc shape along an outer peripheral surface of the rotary shaft in the circumferential direction of the rotator core so that an area of the air hole portion is larger than an area of the fastening hole, and

wherein when a spread angle of the air hole portion in the circumferential direction is represented by θ

1 and a pitch of a corresponding pair of the magnetic poles is represented by θ

2, θ

1≧

θ

2 is established.

3. A permanent magnet buried type electric motor according to claim 1, wherein the air hole portion is formed into such a shape that includes a protruding portion toward the radially outer side of the rotator core, and a portion extending along an inner defining line of the magnet accommodating hole in the circumferential direction of the rotator core.

4. A permanent magnet buried type electric motor according to claim 1, wherein a thickness of the magnet accommodating hole in a short-side direction is set to be minimum at a magnetic pole center portion and be gradually increased toward the radially outer side of the rotator core.

5. A permanent magnet buried type electric motor according to claim 1, wherein each of the plurality of air hole portions comprises a plurality of divided space portions.

6. A permanent magnet buried type electric motor according to claim 1,

wherein an air gap is secured between the outer peripheral surface of the rotator core and an inner peripheral surface of the stator, and

wherein a thickness of a pole center portion of the permanent magnet is set to be eight times as large as a width of the air gap or more.

8. A compressor, comprising a motor and a compression element in an airtight container,

the motor comprising the permanent magnet buried type electric motor of claim 1.

2. (canceled)

7. (canceled)