PERMANENT MAGNET TYPE BRUSHLESS MOTOR, AND ELECTRIC POWER STEERING APPARATUS USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a permanent magnet type brushless motor which suppresses the cogging torque to reduce vibration and noise, and an electric power steering apparatus having good handle-operating feeling using the brushless motor. SOLUTION: The permanent magnet type brushless motor is provided with a rotor having a plurality of permanent magnets which form a plurality of magnetic poles arranged around a rotary shaft or annular permanent magnets which are maltipole-magnetized, and a stator iron core which is provided facing the rotor and wherein a plurality of teeth are projectively provided in the center shaft direction and which is formed as a closed slot having a connecting part which connects between the teeth where the teeth tip ends near the rotor side are adjacent to each other. The inner peripheral surface shape of the rotor iron core which is formed of the tip end part of the teeth facing the periphery of the rotor and of the connecting part is symmetrical with respect to each center line of the teeth, other than a circle. COPYRIGHT: (C)2007,JPO&INPIT