Patent ID: 7683520
Filing Date: 2010-03-23
Classification: H02K

Abstract:
1. An electric motor comprising: an inner periphery side rotor provided with inner peripheral permanent magnets disposed along a circumferential direction thereof; an outer periphery side rotor provided with outer peripheral permanent magnets disposed along a circumferential direction thereof such that a rotational axis thereof is coaxial with a rotational axis of the inner periphery side rotor; and a rotating device that can change 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 about the rotational axis, wherein the rotating device: includes a first member integrally and rotatably fixed to the outer periphery side rotor, and a second member integrally fixed on an inside of the inner periphery side rotor which together with the first member defines a pressure chamber on the inside of the inner periphery side rotor; changes the relative phase between the inner periphery side rotor and the outer periphery side rotor by supplying a hydraulic fluid to the pressure chamber; and also includes a linking passage that leaks the hydraulic fluid supplied to the pressure chamber to an outside of the pressure chamber, wherein the linking passage is through a hole from the pressure chamber provided in the second member to an outer periphery.