| US 7,592,734 B2 | ||
| Three-phase permanent magnet brushless motor | ||
| Yuji Enomoto, Hitachi (Japan); Akeshi Takahashi, Hitachi (Japan); Motoya Ito, Hitachinaka (Japan); Ryoso Masaki, Hitachi (Japan); Katsuyuki Yamazaki, Chiba (Japan); Masahide Yamazaki, Funabashi (Japan); Masashi Kitamura, Mito (Japan); Chio Ishihara, Tokyo (Japan); Kazuo Asaka, Matsudo (Japan); Shoji Ohiwa, Saitama (Japan); and Yasuaki Motegi, Sano (Japan) | ||
| Assigned to Hitachi Industrial Equipment System Co., Ltd., Tokyo (Japan); Japan Servo Co., Ltd., Tokyo (Japan); and Hitachi Powered Metals Co., Ltd., Chiba-ken (Japan) | ||
| Filed on Aug. 17, 2006, as Appl. No. 11/505,295. | ||
| Claims priority of application No. 2005-251360 (JP), filed on Aug. 31, 2005. | ||
| Prior Publication US 2007/0046130 A1, Mar. 01, 2007 | ||
| Int. Cl. H02K 1/12 (2006.01) | ||
| U.S. Cl. 310—254 [310/261; 310/44] | 4 Claims |
| 1. A three-phase permanent magnet brushless motor comprising:
a stator having three-phase windings; and
a rotor having a permanent magnet with a plurality of poles for serving as a field magnet,
wherein said stator comprises a stator core which includes a powder core that is compacted at a high density in at least teeth
thereof, and
a combination of the number of magnetic poles of said rotor with the number of slots of said stator satisfies a condition
that a least common multiple of the number of slots and the number of magnetic poles is 60 or more in a region in which the
number of magnetic poles is 16 or less, and the number of slots is 12 or less.
|