COUNTER ROTOR MECHANISM

PROBLEM TO BE SOLVED: To provide a counter rotor mechanism capable of increasing flexibility in setting a speed ratio between the input side and the output side without excessively upsizing the structure when the counter rotor mechanism is used as a power transmission mechanism. SOLUTION: The counter rotor mechanism includes: an inner rotor 12 made of magnetic material; an outer rotor 14 made of magnetic material, which is arranged in a concentric manner with the inner rotor 12 outward in a radial direction of the inner rotor 12; and a stator 16 with magnets, which is mounted outward in a radial direction of the outer rotor 14. A portion of the circumferential surface of the inner rotor 12 is provided with internal teeth 28 having a plurality of inner teeth elements 30. At a portion of the outer rotor 14 facing the inner teeth 28 in a radial direction, there is provided a cylindrical portion 32 with holes having a plurality of pillar portions 36. Each pitch Pi in a circumferential direction of the inner teeth elements 30 is different from each pitch Po in the circumferential direction of the pillar portions 36. On the inner circumferential portion of the stator 16 with magnets, portions with higher magnetic field strength and portions with lower magnetic field strength are alternately allocated in the circumferential direction. COPYRIGHT: (C)2009,JPO&INPIT