Patent ID: 9490673
Filing Date: 2016-11-08
CPC Classification: H02K

Claim Text:
1. A brushless motor that includes a stator that includes windings of a plurality of phases, and a rotor that is disposed inside the stator in a rotatable manner and which includes a plurality of internal mounting holes in which a plurality of permanent magnets are embedded, wherein a direction of magnetic flux formed by each of magnetic poles of the plurality of permanent magnets is set as d-axis, an axis that is magnetically orthogonal to d-axis is set as q-axis, a plurality of the d- and q-axes are alternately provided in a circumferential direction on the rotor, and the rotor is rotated by reluctance torque generated by a difference in magnetic resistance between the d-axis and q-axis directions and by magnet torque generated by the permanent magnets, the brushless motor wherein: the plurality of permanent magnets include permanent magnets that are arc-shaped in cross-section and form a first magnetic pole which is N- or S-pole, and permanent magnets that are arc-shaped in cross-section and form a second magnetic pole that is different in polarity from the first magnetic pole; each of the permanent magnets that form the first and second magnetic poles is embedded in the rotor in such a way that a convex side portion thereof faces a center of the rotor; and when a cross section of the rotor is equally divided into regions to which each of the d-axes belongs with respect to each of the d-axes of the first and second magnetic poles, the permanent magnets of the first magnetic pole side are disposed in such a way as to protrude into a region of the second magnetic pole side without interfering with the permanent magnets of the second magnetic pole side.