US Patent 7993230 Dual path hydromechanical powertrain

A hydromechanical powertrain for a ground vehicle. The powertrain, more specifically a transmission, includes an input shaft that is coupled to a rotational power source and an output shaft that is coupled to a load. A first hydrostatic unit coupled to a first gear, while a second hydrostatic unit is selectively coupled to one of a pair of clutches. The first of the clutches has a first clutch gear that is selectably coupled to a first mode gear, which is in turn rotationally fixed to the output shaft. The second of clutches has a second clutch gear that is selectively coupled to a second mode gear, which is in turn rotationally fixed to the input shaft. Also coupled to the input shaft is a planetary gear set.