Abstract: A hydrostatic drive in which the ratio of pressure to force is constant is provided having a consumer of hydraulic energy connected to a high pressure system line, a first displacement means interposed between the consumer and the pressure system line, speed regulating means acting on the first displacement means to regulate the speed thereof, a second displacement means connected to the first displacement means by a drive shaft and receiving fluid from the pressure system line, volume output adjusting means acting on one of said first and second displacement means to adjust the volume output per revolution and coupling means connecting the adjustable displacement means with the consumer of hydraulic energy.

Abstract: A drive unit is provided consisting of an internal combustion engine, a continuously variable transmission unit and a fluid operated regulating assembly interconnecting said internal combustion engine and transmission and operated by a single manual control. A second manual control may be provided for interconnecting the engine and a stroke mechanism drive independently of the transmission for operating an auxiliary hydraulic or like circuit.

Abstract: A hydraulic piston motor, preferably a hydrostatic motor of the axial-piston type, has its pistons hydrostatically urged against a surface which is moved relative to or with the pistons in order to reduce static frictional retardation of the pistons upon starting the motor.

Abstract: A stepless, preferably hydrostatic, transmission is provided for an internal-combustion engine and the system is controlled by an operating member. A mechanism connects the members to the transmission and the engine so that both the engine and the transmission controls respond to this member. Means is provided for affecting the linkage in response to the torque on the transmission shaft, preferably in dependence upon the pressure in a transmission-fluid line.