Motor-assisted bicycle has stator installed opposite rotor core integrated into hub of wheel, and several spaced apart opening sections formed in rotor core and open in axial direction of wheel each house permanent magnet

摘要

The motor-assisted bicycle includes a stator (38) installed opposite a rotor core (321) integrated into the hub (32) of the wheel. Several opening sections are formed in the rotor core in such a way that they are open in the axial direction of the wheel and spaced apart at predetermined intervals in the wheel's circumferential direction. A permanent magnet is contained in each of the opening sections, and gaps are located at both ends of the opening section in the wheel's circumferential direction. A commutation pole (323) which forms a part of the rotor core is installed between adjacent opening sections, and a polarity of one of the permanent magnets installed in one the two adjacent opening sections is different from a polarity of an additional permanent magnet installed in the other of the adjacent opening sections.