Motor having characteristic structure in armature and disc apparatus

摘要

The invention provides a motor which can reduce a generation of a cogging, has a thin size, and can generate a strong torque. In a motor having an armature including a back yoke formed in a cylindrical shape and a wound coil and a magnet formed in a cylindrical shape and magnetized by a plurality of magnetic poles on a cylindrical circumferential surface, the back yoke forms a convex portion protruding from the back yoke toward the magnet in a current switching portion of the coil. The invention further provided a disc apparatus using the motor mentioned above.