Motor/generator having two rotors

A motor/generator comprising:

• an inner rotor having a plurality of magnetic poles;
• an outer rotor having a plurality of magnetic poles which differs from the number of magnetic poles of the inner rotor;
• and
• a ring-shaped stator disposed between the inner rotor and the outer rotor, the stator being provided with a plurality of coils, the coils simultaneously generating a magnetic field synchronized with the rotation of the inner rotor and a magnetic field synchronized with the rotation of the outer rotor, and a plurality of cores on which the coils are wound, the cores being arranged in a circumferential direction and composed of a magnetic material and having a connector magnetically connecting a part of a single core to a part of an adjacent core so as to set a magnetic resistance in a circumferential direction of an inner peripheral section of the cores located between the inner rotor and the coils and a magnetic resistance in a circumferential direction of an outer peripheral section of the cores located between the outer rotor and the coils,
• wherein the stator, the inner rotor and the outer rotor are disposed co-axially with respect to a rotation shaft, and cores are formed by a plurality of tooth members laminated in a direction along the rotation shaft,
• wherein the cores are formed by a first plate unit comprising a plurality of first tooth members disposed at equal intervals on a circumferential periphery, adjacent first tooth members on the circumferential periphery being insulated by a gap, and a second plate unit comprising the same number of second tooth members as the number of the first tooth members, the second tooth members being disposed at equal intervals on a circumferential periphery and provided with connectors between adjacent tooth members on a circumferential periphery, and the first plate unit and the second plate unit are laminated in the direction of the rotation shaft at a predetermined number ratio, and
• wherein the second plate unit comprises a single magnetic plate which has second tooth members, inner peripheral sections of which are made to be contiguous in a circumferential direction and the connectors comprise contiguous parts of the inner peripheral sections of the second tooth members.