Patent ID: 8137228

Claim:
A transmission system comprising: an input shaft; an output shaft; a mechanical transmission section; and an electric transmission section; wherein the mechanical transmission section and the electric transmission section are interposed between the input shaft and the output shaft; wherein the electric transmission section includes a plurality of generators/motors which are drivingly controlled by an inverter, the plurality of generators/motors including a first generator/motor, a second generator/motor, and a third generator/motor; wherein the mechanical transmission section has a first planetary gear train and a second planetary gear train; wherein a sun gear of the first planetary gear train is continuously connected to the input shaft, a carrier of the first planetary gear train is continuously connected to a sun gear of the second planetary gear train and is connected to the first generator/motor, a ring gear of the first planetary gear train is connected to the second generator/motor, and a ring gear of the second planetary gear train is connected to the output shaft; wherein a first clutch is provided for engaging and disengaging a carrier of the second planetary gear train and the ring gear of the first planetary gear train with and from each other; wherein a second clutch is provided for engaging and disengaging the carrier of the second planetary gear train and a fixed end with and from each other; and wherein a switching mechanism is provided for selectively connecting the third generator/motor to a first generator/motor side or a second generator/motor side.