Patent ID: 8594875

Claim:
A power output system comprising an internal combustion engine, an electric motor, and a transmission including two transmission shafts which are connected to the internal combustion engine, wherein the electric motor comprises a stator which generates a revolving magnetic field, a primary rotor which includes a plurality of magnetic pole portions and faces the stator in a radial direction, and a secondary rotor which includes a plurality of magnetically soft portions and which is provided between the stator and the primary rotor and is configured so as to rotate while keeping a collinear relation between a revolving speed of a magnetic field of the stator, a rotating velocity of the primary rotor and a rotating velocity of the secondary rotor, wherein the primary rotor is connected to either of the two transmission shafts, wherein the secondary rotor is connected to a drive shaft, and wherein the other transmission shaft of the two transmission shafts transmits power to the drive shaft without involving the electric motor.