Motor

A motor comprising:

• an annular stator having a plurality of teeth each extending toward a central axis and arranged in alignment with each other in a circumferential direction and windings wound on the teeth;
• and
• a rotor having a rotor core rotatably accommodated inside the stator and a plurality of permanent magnets provided in the rotor core and arranged in alignment with each other in the circumferential direction, the rotor also having a plurality of magnetic pole portions formed by the plurality of permanent magnets on a surface of the rotor core which faces the stator and aligned with each other in the circumferential direction,
• wherein:
• at least some of the magnetic pole portions each have a groove recessed radially inward;
• in each of the at least some of the magnetic pole portions, the groove is formed symmetrically in the circumferential direction with respect to a magnetic pole center which is a circumferential center of the magnetic pole portion;
• and
• 10.2 < Wg/(360/P) < 0.31, where Wg is an angle of a width of the groove at a radially outer end thereof, and P is the number of the magnetic pole portions.