Patent ID: 6633105
Filing Date: 2003-10-14
Classification: H02K

Abstract:
A permanent magnet motor comprising a stator and a permanent magnet rotor facing the stator with an air gap therebetween, the stator having a plurality of stator magnetic poles extending radially toward a peripheral surface of the rotor, s number of small stator teeth formed on a tip end of each of the magnetic poles, and exciting windings of m phases wound around the stator magnetic poles, and the rotor having a cylindrical permanent magnet having pieces of N pole and pieces of S pole arranged alternately in a peripheral direction thereof at equal pitches, wherein a pitch of the small stator teeth is 1Â±1/(2ms) times larger than a pitch of the rotor magnetic pole pairs, wherein the width of the small stator tooth is 37Ëœ47% of the pitch of the rotor magnetic pole pairs, and wherein a depth of the groove formed between the adjacent small stator teeth is more than 15 times larger than the length of the air gap between the stator and the rotor.