MOTOR

摘要

In a permanent-magnet motor, the number of magnetic poles of a rotor (22) is 2P (P is an integer of 1 or more) and the number of salient poles of a stator field core (21) is 3P. Each salient pole section (21a) of each stator field core (21) is provided with two auxiliary grooves (24) which are spaced at angular positions of theta and 3 theta from the center of a winding groove (27) in the circumferential direction of the rotor (22) when the angle between the salient poles and magnetic poles is 4 theta . The cogging torque of the motor is reduced, because the fundamental wave component of the cogging torque is eliminated.