Abstract: A ball and piston valve for controlling the flow of hydraulic fluid to a motive means have the ball and piston spring biased in opposing directions and with both initially subject to a first hydraulic fluid pressure that allows the springs to cause the ball to be unseated from its seat whereby fluid is directed to a fluid tank and wherein the ball is of sufficiently larger diameter than the piston that upon an increase in fluid pressure the ball is seated and remains seated when the pressure drops to the first hydraulic fluid pressure whereby the motive means to which the fluid is directed when the ball is seated does not have a sudden lurch upon a subsequent increase in pressure.

Abstract: A hydrostatic continuously variable transmission includes a closed hydraulic circuit comprising a hydraulic pump, a hydraulic motor, and an oil supply passage connected between the hydraulic pump and the hydraulic motor. The hydraulic pump selectively generates a first oil pressure lower than a first predetermined pressure level, a second slowly-changing oil pressure higher than the first predetermined pressure level when the transmission is in normal operation, and a third rapidly-changing oil pressure higher than a second predetermined pressure level higher than the first predetermined pressure level when the transmission starts to operate.

Abstract: A hydraulically operated power transmission apparatus transmits the output power from a power source at a selected speed ratio. The power transmission apparatus includes a casing having an opening in one end thereof, a base plate attached to the end of the casing in covering relation to the opening, the casing and the base plate jointly serving as a transmission case defining a closed space therein, a hydraulic pump having a pump drive shaft adapted to be operatively coupled to the power source, the hydraulic pump being disposed in the closed space, a hydraulic motor having a motor output shaft and drivable by a hydraulic pressure generated by the hydraulic pump, the hydraulic motor being disposed in the closed space, a pair of output shafts extending through the casing and the base plate, respectively, and disposed coaxially with each other, a differential mechanism disposed in the closed space and operable by the motor output shaft, the differential mechanism being coupled to the output shafts.

Abstract: A transmission includes a transmission casing, a speed reducer mechanism housed in the transmission casing, a hydrostatic power unit mounted on the transmission casing, the hydrostatic power unit comprising a pump having a pump shaft and a motor having a motor shaft, the pump shaft and the motor shaft extending parallel to each other, and an input shaft operatively coupled to the pump shaft. The transmission casing has an interior space divided into a first chamber in which the input shaft is disposed and a second chamber in which the speed reducer mechanism is accommodated.

Abstract: A hydraulic transmission apparatus comprises an input unit to which power from a power source is applied in a first direction, a direction changing unit hydraulically coupled to the input unit for extracting power in a second direction which is different from the first direction, and a case supporting the input unit and the direction changing unit. The input unit and the direction changing unit comprise an oil pump and an oil motor mounted respectively on one surface and another surface of the case. The case is filled with working oil for operating the oil pump and the oil motor.