Patent ID: 8004138

Claim:
A motor comprising an inner rotor having inner permanent magnets arranged in a peripheral direction and an outer rotor having outer permanent magnets arranged in the peripheral direction, the mutual axes of rotation of the inner rotor and the outer rotor being arranged coaxially, and a rotating device capable of making at least one of the inner rotor and the outer rotor rotate around the axes of rotation so as to change the relative phase between the inner rotor and the outer rotor, wherein the rotating device includes: a first member which is integrally and rotatably provided with respect to the outer rotor; and a second member which is integrally and rotatably provided with respect to the inner rotor and which defines pressure chambers inside the inner rotor with the first member, and wherein a working fluid is supplied to the pressure chambers, thereby changing the relative phase between the inner rotor and the outer rotor.