MOTOR

摘要

A motor comprises a stator which includes a stator core having an annular stator yoke and a plurality of inner and outer teeth projecting from the stator yoke toward the inner and outer sides and a plurality of coils wound around the stator core; and an inner rotor and an outer rotor facing the inner and outer teeth with spaces formed therebetween and having permanent magnets embedded therein. The cross sectional shapes of the outer rotor and the inner rotor are connected to each other with a circular arc and at least two continuous straight lines following to the circular arc in the direction from the magnetic pole center line to the magnetic flux boundary line.