Abstract: A vehicle drive system utilizing an engine controlled to operate at a substantially constant speed during vehicle operation. Means are provided to vary that engine speed in accordance with different types of operation. The engine powers an hydraulic pump, the output flow from which is varied to determine the vehicle speed. An hydraulic motor receiving fluid from the pump is driven thereby and is coupled to the drive shaft of the vehicle.

Abstract: A drive mechanism for powering the drive wheel of a vehicle utilizing a drive shaft powered at a substantially constant speed. A transaxle mechanism is utilized having a power input shaft coupled to the drive shaft. The transmission of power through the transaxle mechanism to the output shaft, and the speed of the vehicle, is controlled by the selective braking of a control shaft forming a part of the transaxle mechanism. The drive shaft is advantageously driven by an electric motor operated at substantially constant speed, energized by an electric generator which is in turn driven by an internal combustion engine operated at substantially constant speed.