A motor may include a rotor comprising a shaft; a stator; and a bearing supporting the shaft. The rotor may include a plurality of core piece parts arranged along a circumferential direction; and a plurality of permanent magnets arranged between neighboring core piece parts. The permanent magnets may include two magnetic poles, and the magnetic poles of neighboring permanent magnets being arranged such that magnetic poles with identical polarity face each other in the circumferential direction. The core piece parts may include a concave portion, and two protrusions which are disposed on both sides of the concave portion and protrude radially inward. The protrusions may a portion located on a radially inner side from the first segment when viewed in an axial direction.