Abstract:
An axial piston type fluid energy translating device has fluid passages in the pistons, shoes, swash plate and cam member to conduct fluid from the high pressure port to pockets on the back of the cam member adjacent the cam support. The high pressure fluid in the pockets counter-balances the force applied to the swash plate and cam member by the pistons exposed to high pressure fluid.
Abstract:
An electronically programmable pressure and flow control hydraulic circuit. The circuit comprises a pair of electronically programmable pressure control valves, one of which is cooperable with a pressure reducing valve and one or more orifices to control flow through the circuit and the other of which controls pressure in the circuit. When the circuit is used in combination with a hydraulic ram or motor, it enables both the force and speed of the ram or motor to be electronically controlled and programmed.
Abstract:
An automatic control system for an across-center axial piston pump which destrokes the pump when fluid pressure or flow exceeds a predetermined maximum and returns the pump to its previous setting when fluid pressure or flow falls below the maximum.
Abstract:
A closed loop hydrostatic transmission for transmitting rotary power from a reversible fluid pump to a reversible fluid motor. The transmission includes a novel combination dual relief and shuttle valve operable to relieve excessive pressure from whichever is the higher pressure of two main lines of the loop circuit and to connect whichever is the lower pressure or pump inlet line of the two main lines to a replenishment oil circuit. Two different hydrostatic transmissions are disclosed; one a full boost transmission in which all of the flow from a booster pump is inserted into the closed loop circuit and the other a partial boost transmission in which only makeup oil required for replenishment of oil leakage is inserted into the closed loop circuit.
Abstract:
A control valve which has a poppet and a freely movable selfaligning seat. A groove is provided between a seat surface and a mating valve body surface and is in communication with a low pressure source providing a pressure imbalance which forces the seat against the valve body surface.
Abstract:
An electronically programmable pressure and flow control hydraulic circuit. The circuit comprises a pair of electronically programmable pressure control valves, one of which is cooperable with a pressure reducing valve and one or more orifices to control flow through the circuit and the other of which controls pressure in the circuit. When the circuit is used in combination with a hydraulic ram or motor, it enables both the force and speed of the ram or motor to be electronically controlled and programmed.