Patent ID: 6876116

Claim:
A permanent magnet motor comprising: a rotor having M magnetic poles disposed at an interval in a peripheral direction of the rotor; a stator having P magnetic pole pieces arranged at a spacing in the peripheral direction, the P magnetic pole pieces being opposed to the M magnetic poles of the rotor; respective slots between adjacent magnetic pole pieces of the stator, wherein 0.25 <b/a< 0.82, b is depth of each of the auxiliary grooves in the faces of the P magnetic pole pieces, transverse to the peripheral direction, and a is depth of each of the P magnetic pole pieces adjacent to the slots, transverse to the peripheral direction; and n auxiliary grooves in a face of each of the magnetic pole pieces of the stator opposed to the magnetic poles of the rotor, wherein the smallest integer of which M and (n+1)·P are factors is X, m satisfies 61<(180 mM)/X<84, M, P, m, and n are integers, and a skew having an electrical angle in a range of 61° to 84° is provided relatively between the rotor and the stator on at least one of the rotor and the stator.