A stationary portion of a motor includes a stator core, insulators, and coils. The stator core includes a core back having an annular shape, and a plurality of teeth extending radially inward from the core back. A radially inner end portion of each tooth has a circumferential width substantially equal to or smaller than a circumferential width of a remaining portion of the tooth. The core back includes a protruding portion protruding radially inward between adjacent teeth, a cut extending radially outward from the protruding portion, and a through hole extending in an axial direction through the core back defined at a radially outer end portion of the cut. The protruding portion increases a radial dimension of the core back to achieve a reduction in magnetic reluctance in the vicinity of the cut.