Parker-hannifin Corporation

Jarmo Antero Harsia

Germano Franzoni

Roger Lowman

Patrick Stegemann

A valve member having a supply pressure and a method of controlling the supply pressure in the valve member includes a valve body having a fluid inlet, a fluid outlet, and a controlled port. The valve member includes a spool moveable within the valve body to fluidly connect at least one of the fluid inlet and the fluid outlet with the controlled port. The spool includes an end in fluid communication with a control pressure port and a pin received within the end of the spool that is moveable relative to the spool. Fluid flow through the control pressure port acts against a cross-sectional area of the pin and an annular area of the spool to modulate the supply pressure through the valve member.

Proportional sequence valve with pressure amplification device

A method of controlling a float function of a cylinderhaving a first side and a second side includes connecting the second side of the cylinder to a reservoir; connecting the first side of the cylinder to an output of a pumpand to the reservoir; and supplying an amount of flow from a pump less than an amount supplied by the pump under loaded conditions. A three-position directional control valvehaving a pump port, a reservoir port, a first cylinder port, and a second cylinder port may be provided to effectuate aspects of this method.

Electro-hydraulic system with float function

A load sense open center hydraulic system provides efficiency and operator feedback and includes one or more constant flow-open center valves (); respective one or more parallel power cores () operatively coupled to the one or more constant flow-open center valves; a variable capacity pump () directly fluidly connected to the one or more parallel power cores; and a pressure compensated flow control fluidly connected between the variable capacity pump and the one or more constant flow-open center valves. The one or more constant flow-open center valves are not fluidly coupled to a fixed capacity pump.

Variable load sense open center hybrid system

A cushioned swing circuit provides the reduction of oscillation common in the operation of heavy equipment such as with boom members. The circuit utilizes a transfer of high pressure fluid flow (caused by the inertial of the swing during rapid deceleration) from one leg of the circuit to the other leg of the circuit or to the sump which serves as decompression for the oil that would ordinarily be trapped in the leg. These phenomena create the swing cushioning effect.

Cushioned swing circuit

A smart flow sharing system, useful in hydraulic systems having more than one hydraulically demanding equipment function wherein more than one of the hydraulically demanding functions are sometimes activated at the same time, has modified hydraulic passages and at least two fixed displacement pumps. The system automatically prioritizes hydraulic fluid flow so that when only one of two hydraulically demanding functions is activated by an operator, it receives the hydraulic fluid flow from both fixed displacement pumps, but when both hydraulically demanding functions are activated, one of the functions receives hydraulic fluid flow from the first fixed displacement pump, and the other function separately receives hydraulic fluid flow from the second fixed displacement pump. The smart flow sharing system accomplishes the foregoing without resorting to complex hydraulics or expensive additional components. An equipment operator advantageously achieves superior controllability and quicker movement of equipment functions using the invention.

Smart flow sharing system

A fixed/variable hybrid system has modified constant flow open center hydraulic valves ('fixed/variable valves'), including an open center core, spools, a power core, and a tank galley. A small fixed displacement pump provides fluid at a constant rate to the open center core. A variable displacement piston pump provides fluid directly to the power core as needed. Activation of spools partially restricts the open center core causing an increase in fluid pressure that is communicated to the variable displacement piston pump's load sense signal port, causing the pump to increase fluid flow and pressure to the power core. Activated spools direct pressurized fluid from the power core to the applications through selected hydraulic ports. Activated spools also direct fluid flow from selected hydraulic ports via the tank galley to a hydraulic tank. Pumping the majority of fluid only on an as-needed basis results in significant efficiencies.

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Lincolnshire, IL, United States of America

Jarmo Antero Harsia