BRUSHLESS MOTOR

PROBLEM TO BE SOLVED: To provide an optimal motor structure for reducing cogging torque surely in a brushless motor subjected to pseudo multi-slotting. SOLUTION: The brushless motor 1 comprises a rotor 3 provided with a ring magnet 2, and a stator 4 arranged with a plurality of tees 8 along the circumferential direction at a pitch P wherein N sub-tees 11 are formed at the forward end part of the tees 8 along the circumferential direction at a pitch P/N. The ring magnet 2 is magnetized such that the pitch between the maximum values of repulsion (-) and attraction (+) acting between the sub-tees 11 and the ring magnet 2 in the vicinity of a pole boundary 12 becomes P/N when the sub-tee 11 passes the pole boundary 12 of the ring magnet 2. Positive and negative maximum values of cogging force are significantly canceled by the maximum values of cogging force being generated by adjacent sub-tees 11 and the total cogging force is reduced greatly. COPYRIGHT: (C)2003,JPO