Patent ID: 7569970
Filing Date: 2009-08-04
Classification: H02K

Abstract:
1. An electric motor comprising: an inner periphery side rotor provided with inner peripheral permanent magnets with unlike poles, which are disposed alternately along a circumferential direction of the inner periphery side rotor; an outer periphery side rotor provided with outer peripheral permanent magnets with unlike poles, which are disposed alternately along a circumferential direction of the outer periphery side rotor, the outer periphery side rotor being arranged such that a rotational axis thereof is coaxial with a rotational axis of the inner periphery side rotor; and a rotating device that varies a relative phase between the inner periphery side rotor and the outer periphery side rotor by rotating at least the inner periphery side rotor or the outer periphery side rotor around the rotational axis, and sets a variable width of the relative phase between the inner periphery side rotor and the outer periphery side rotor within a range of an electrical angle of below 180°, wherein the rotating device comprises a pressure chamber on the inside of the inner side rotor and varies the relative phase between the inner periphery side rotor and the outer periphery side rotor by supplying a hydraulic fluid to the pressure chamber.