Permanent magnet rotary motor

• US 7,560,844 B2
• Filed: 03/24/2006
• Issued: 07/14/2009
• Est. Priority Date: 03/25/2005
• Status: Expired due to Fees

• Current Assignee: Sanyo Denki Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Denki Company Limited (Panasonic Holdings Corporation)
• Inventors: Takizawa, Kazuhiko, Koyama, Masahiro, Onodera, Satoru, Miyashita, Toshihito, Kitazawa, Kazuyuki
• Primary Examiner(s): Leung; Quyen
• Assistant Examiner(s): Kim; John K
• Application Number:
  US11/388,697
• Publication Number:
  US 20060214533A1
• Time in Patent Office: 1,208 Days
• Field of Search: 310/216, 310/258, 310/156.01, 310/259, 310/218, 310/217, 310/42, 310/43, 310/12, 310/254, 310/256
• US Class Current: 310/216.092
• CPC Class Codes: H02K 29/03 with a magnetic circuit specially adapted for avoiding torque ripples or self-starting problems

Abstract

A permanent magnet rotary motor is provided in which cogging torque can be reduced and an increase in copper loss can also be prevented. A first divided core unit 13 is combined with a second divided core unit 15, thereby constituting a stator core 9. The first divided core unit 13 constitutes a yoke portion 17. The second divided core unit 15 includes pole pieces 25, magnetic pole surface constituent portions 27, and first and second type connecting portions 29A and 29B each mutually couple two adjacent magnetic pole surface constituent portions 27, all of which are formed integral with one another. The thickness of the first type connecting portions 29A in a radial direction of the stator core 9 is set to be smaller than the thickness of the second type connecting portions 29B in the radial direction of the stator core 9.

Claims

1. A permanent magnet rotary motor comprising:

a rotor comprising;

a rotor core; and

permanent magnet magnetic pole portions comprising P (p;

a natural even number) permanent magnets mounted to said rotor core;

a stator core comprising;

an annular yoke;

N pole pieces (N;

a natural even number) arranged on an inside of said annular yoke at intervals in a circumferential direction of said annular yoke, each of said N pole pieces having one end fixed to said yoke portion and the other end located more inwardly in a radial direction of said stator core than the one end;

N slots each located between two adjacent pole pieces of said N pole pieces;

a plurality of magnetic pole surface constituent portions each located at the other end and each having a magnetic pole surface facing said rotor; and

a plurality of connecting portions each mutually coupling two adjacent magnetic pole surface constituent portions of said magnetic pole surface constituent portions; and

a plurality of exciting winding portions provided respectively at said N pole pieces,

wherein said connecting portions are divided into two types, first type connecting portions and second type connecting portions, said first type connecting portions being alternately arranged in the circumferential direction, said second type connecting portions being so arranged as to alternate with said first type connecting portions in the circumferential direction,

wherein a thickness T1 of each of said first type connecting portions in the radial direction is smaller than a thickness T2 of each of said second type connecting portions in the radial direction, and

wherein the stator core has an annular flat surface facing the rotor.

2. The permanent magnet rotary motor according to claim 1, wherein the number of said permanent magnet magnetic pole sections P and the number of said slots N have a relation of P=4 m and N=6 m (m:

a natural number); and

the thicknesses T1 and T2 have a relation in which a ratio T2/T1 is in the range of two to three.

3. The permanent magnet rotary motor according to claim 1, wherein said stator core comprises a combination of divided core units of a plurality of types, each constituted by lamination of a plurality of electromagnetic steel plates;

and

said divided core unit comprises;

a first divided core unit constituting said yoke portion; and

a second divided core unit constituted integrally by said pole places, said magnetic pole surface constituent portions, and said connecting portions, said pole pieces, said magnetic pole surface constituent portions.