Patent ID: 7906880

Claim:
A brushless motor comprising: a rotor having 2n magnetic poles (n being a positive integer) arranged in a circumferential direction; and a stator having 3n slots, wherein the magnetic poles of the rotor are composed of segment magnets arranged in three columns extending in an axial direction, each of the columns having segment magnets arranged such that the segment magnets of each column are offset from the segment magnets of either adjacent column in the circumferential direction so as to form a step-skew structure, and the segment magnets are arranged so that the step-skew structure has a skew angle θskew ranging from 60° to 75° in terms of electrical angle; and the segment magnets are arranged so that the step-skew structure has a center angle θm expressed as: (140 ×n− 1)°≦θ m ≦(159 ×n− 1)° such that the segment magnets of each of the columns are arranged not to overlap in the circumferential direction when the segment magnets are arranged to form the step-skew structure having the skew angle θskew.