Abstract: An axial piston machine with a variable or adjustable stroke comprises a rotatable cylinder drum provided with annularly spaced cylinder bores each of which receives a piston reciprocal in its bore parallel to the axis of rotation of the drum and with a stroke determined by the extent of tilt of a guide surface about an axis perpendicular to the axis of rotation of the drum. The piston stroke is controlled by a rocker carrying the control surface and hydraulically displaceable in the machine housing by application of hydraulic fluid pressure directly to the rocker.

Abstract: In an output control device for a hydraulic pump of the variable displacement type wherein delivery pressure is led into a cylinder of the control device to move a control piston therein back and forth and let the piston change the inclination of a yoke, thereby varying the delivery of the pump, the improvement comprising a cam formed on a piston rod directly connected to the control piston, a hollow cylindrical sleeve slidable in the direction at right angles to the piston rod and adapted to remain in sliding contact with the cam so that, with the displacement of the control piston due to a rise of fluid pressure, the sleeve can be displaced by the cam away from the piston rod, said sleeve having a pressure pickup hole communicated with a fluid passage leading to the cylinder, a compensator piston slidably fitted in the sleeve and adapted to close the pressure pickup hole and shut off the flow of pressure fluid into the cylinder when the fluid pressure is zero and be moved, with the rise of fluid pressure, a

Abstract: A control for an axial piston type variable displacement fluid energy translating device has an auxiliary control device which connects to a manual control and provides a variety of operating functions for the fluid energy translating device.

Abstract: Control valve assemblies are taught which can be inserted into or associated with a basic primary unit for causing such basic primary unit to perform with optimum performance characteristics as a pump or motor, and a master or slave unit, etc. The function that the basic primary unit performs depends upon the control valve assembly selected. In the preferred embodiment of the control valve assembly, there is provided a central coaxial probe which passes through a bore in the spool valve body and is reponsive to a signal which is in addition to the other signals being sensed by the control valve assembly.

Abstract: A variable displacement axial piston pump has a rocker cam for controlling the output of the pump. The rocker cam is driven by a fluid motor member. A valve with a follow-up device regulates pressure fluid flow to the fluid motor member to move the rocker cam. Both the fluid motor member and a part of the follow-up device are rigidly secured to and movable with the rocker cam to provide precise positioning of the rocker cam.

Abstract: An hydraulic system is disclosed for driving a plurality of hydraulic power units, such as warping and retaining winches on ships, each connected to an hydraulic supply network with a constant network pressure. Each hydraulic power unit is adjustable for torque output and a volume regulating device controls the amount of hydraulic fluid supplied to each unit. The torque adjustment and the volume regulation are interconnected to simultaneously control both operating parameters.

Abstract: An axial piston machine of the swashplate type has a movable valve plate at the piston end of the cylinder block, and displacement of the valve plate by a stroke control mechanism changes the tilt of the block. The valve plate has a front face subjected to the hydraulic end thrust of the cylinder block and a back face shaped conformably to and engaged with a cylindrical slideway in the machine body. The valve plate is guided against displacement in the direction of the axis of tilt by side surfaces of the machine body. At least one of the front and back faces is spherically arched to cause the hydraulic end thrust to urge the valve plate in a direction to keep one of its sides in continuous contact with a cooperating side face in the machine body. This prevents jamming and wedging of the valve plate in the slideway when the tilt of the cylinder block is adjusted, regardless of the existing load.

Abstract: A mounting arrangement for a hydraulic motor having a pivotal swash plate and an axially extending drive shaft includes a support structure having an open ended bore formed therein to receive the hydraulic motor and a mounting bracket journalled to the drive shaft of the hydraulic motor. The mounting bracket has a pair of spaced apart lugs which extend toward the hydraulic motor and pivotally engage the swash plate, and an annular pilot portion disposed coaxial with the drive shaft and piloted into a pilot bore formed in an end wall of the support structure opposite to the open end of the bore with the mounting bracket being secured to the end wall.

Abstract: A control device for hydraulic machines with variable displacement comprises a spring-biased control valve member for actuation of hydraulic adjustment means to provide the displacement variation, said valve member being engaged by one end of a double-armed lever on which acts a force proportional to the working pressure of the machine on an arm length relative to a pivot for said lever, which length is variable through a sliding movement of said pivot, and a means for controlling the maximum pressure of the machine. By a pressure means, the slidably movable pivot is resiliently biased against an indicating member responsive to the momentary adjusted displacement of the machine. Moreover, the control means for the maximum pressure of the machine consists of a stationary but adjustable abutment means adapted to restrict the length of the sliding movement of said pivot in order to determine a desired minimum value of said lever arm length and thus the value of the maximum pressure of the machine.

Abstract: The rotary piston pump of a hydrostatic transmission for automotive vehicles has a slide block which is shiftable by a plunger in the cylinder of a follow-up control. The plunger is biased against the slide block by pressurized fluid in a chamber of the cylinder and can be shifted under or against the fluid pressure in the chamber by a control valve wherein a reciprocable spool controls the flow of fluid to the chamber from the pressure outlet of the pump. The spool is shifted in response to changes in fluid pressure at the opposite sides of a flow restrictor installed in a conduit which is connected to the outlet of the pump whereby the spool seals the cylinder of the follow-up control from the tank and from the pressure outlet of the pump before the chamber of the cylinder receives pressurized fluid to thereby change the position of the plunger and slide block.

Abstract: A variable displacement pump control assembly as for an axial piston pump having a swash plate actuating piston characterized in that the control assembly is embodied in the pump housing to provide a pressure compensated pump, or to provide a pressure compensated pump having an auxiliary modulator to control the pressure applied to the swash plate actuating piston to maintain a predetermined pressure drop across a variable area metering orifice embodied as in a directional control valve for a fluid motor, or to provide a pressure compensated pump having a horsepower modulator with or without the auxiliary modulator, said horsepower modulator providing desired control of horsepower in relation to pump delivery pressure and displacement.

Abstract: A low friction seal assembly for a fluid energy translating device seals a pair of pressure fluid chambers from one another. The assembly is mounted in a movable member of the device and has an elastic member which mechanically and hydraulically biases a seal member into engagement with the walls of the device.