This electric motor includes first permanent magnets secured integrally to
an outer periphery side rotor and second permanent magnets secured
integrally to an inner periphery side rotor. The first permanent magnets
and the second permanent magnets are arranged so as to offset the
relative torque produced between the outer periphery side rotor and the
inner periphery side rotor based on the magnetic flux of the inner
peripheral permanent magnets and the outer peripheral permanent magnets.