Abstract: A rotor device includes a casing, an outer rotor positioned in the casing and rotatable about a first rotational axis, and an inner rotor positioned in the casing and rotatable about a second rotational axis. An outer sealing portion of the inner rotor defines a locus along an inner wall surface of an operating chamber of the outer rotor as a result of the rotation of the inner rotor. An inner sealing portion of the outer rotor defines a locus along an outer circumferential surface of the inner rotor in response to the rotation of the outer rotor. The inner wall surface of the operating chamber engages the outer circumferential surface of the inner rotor through a gear engagement. A driving input shaft portion is connected to the outer rotor and a first gear having teeth on its inner circumferential surface is connected to the outer rotor.

Abstract: Disclosed are a starter and power generator which starts an engine and which is subsequently driven by the engine to generate power, and a motor used in the starter, in particular, a self-controlled commutatorless motor in which a rotating magnetic field is developed across the stator in accordance with an angle of rotation of the rotor. Normally, output matching means is connected to the three phase windings of the stator, whereby an alternator is defined by the combination of the rotor, the stator and the output matching means. However, in response to a starting command, energizing means is substituted for the output matching means, whereby a combination of the rotor, the stator, timing means and energizing means form a commutatorless motor. Thus, subsequent to starting the engine, the motor is driven by the engine to generate power.