STRUCTURE OF BRUSHLESS DC MOTOR

摘要

PROBLEM TO BE SOLVED: To provide the structure of a brushless DC motor which can reduce cogging torque. SOLUTION: This brushless Dc motor (hereinafter referred to as motor) is composed of a rotor, to which permanent magnets are attached and a stator with a plurality of slots. The effective pole opening angle of the rotor is set to a value, obtained by adding an angle corresponding to one slot opening to a value of integer times the slot pitch of the stator. The rotor is divided into a plurality of parts in the axial direction, and the respective divided rotor parts are arranged circumferentially, so as to be shifted from each other by mechanical angle amounts corresponding to half a period of respective cogging torques of the divided rotor parts.