Patent ID: 8142319

Claim:
A transmission system comprising: an input shaft; an output shaft; a mechanical transmission section; and a hydraulic transmission section; wherein the mechanical transmission section and the hydraulic transmission section are interposed between the input shaft and the output shaft; wherein the hydraulic transmission section includes a plurality of pumps/motors which are connectable to each other through a hydraulic circuit, the plurality of pumps/motors including a first pump/motor, a second pump/motor, and a third pump/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 pump/motor, a ring gear of the first planetary gear train is connected to the second pump/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 pump/motor to a first pump/motor side or a second pump/motor side.