An example pressure compensator valve includes: a compensator spool; a first piston coupled to a distal end of, and ax-ially-movable with, the compensator spool; a second piston disposed at a proximal end of the compensator spool, wherein the compensator spool is axially movable relative to the second piston; and a compensator spring applying a biasing force on the compensator spool.

A Control Valve Compensation System for producing both a pre-compensated and a post-compensated load sensing hydraulic directional control valve module, wherein both configurations use the same components except for a sliding compensating component. The Control Valve Compensation System generally includes a hydraulic directional control valve housing which is adapted to be easily-interchangeable between a load sensing pre-compensated pressure configuration and a load sensing post-compensated pressure configuration by simply removing and replacing a different compensator assembly within the housing. The compensator assembly is adapted to direct oil flow through the housing while simultaneously providing compensation for the valve function. Directional valve assemblies may be provided, with the valve assemblies functioning to provide post-compensated functions, pre-compensated functions, and mixed pre- and post-compensated functions. These directional valve functions can be re-configured in the field by simply swapping the compensator assemblies to produce the desired functionality of the end-user at that particular time.

Systems and methods for estimating the area ratio of an actuator in static and dynamic states are disclosed. In one aspect, a metering valve is connected to each side of the actuator. In one example, one metering valve is held closed while the other metering valve incrementally pressurizes the actuator in discrete steps. The resulting work port pressures can be used to determine the actuator area ratio. Where counterbalance valves are installed in the system, the pressurizing metering valve can be placed in a pressure control mode to obtain the desired pressure values. In one example, the ratio of flows through each metering valve is used to determine the actuator ratio.

A valve subassembly includes a main spool having a continuously adjustable main orifice and a control spool having adjustable first and second orifices. The control spool has first and second end positions and is acted upon by a first spring toward the first end position. A fluid flow path starts from a pump and runs to an actuator via the first orifice, first control point, second orifice, second control point, main orifice, and third control point. Pressure at the first control point acts on the control spool toward the second end position and pressure at the third control point acts toward the first end position. The second orifice is closed between the first end position and an intermediate position, and opens from the intermediate position to the second end position. The second orifice opening decreases from the intermediate position to the second end position from a nonzero value to zero.

A compensator spool of a load sensing valve device includes a pressure chamber, a compensator throttle portion, a pressure introduction chamber, a pressure introduction port, a maximum load pressure introduction chamber, and a selector valve. A groove is formed around the pressure introduction port, and a groove moves relatively between a passage communicating with an actuator to reduce an opening area of the pressure introduction port when the compensator spool moves.

Systems and methods for controlling valve assemblies associated with an actuator in an electro-hydraulic system are disclosed. In one method, a controller monitors hydraulic fluid flow for an actuator to identify one valve assembly connected to the actuator as a meter-in valve and another valve assembly connected to the actuator as a meter-out valve. In one aspect, the valve assembly most recently identified as the meter-in valve is controlled to maintain a pressure setpoint and the valve assembly most recently identified as the meter-out valve is controlled to maintain a hydraulic fluid flow rate. The method can also include determining whether the actuator is in a passive state or an overrunning state and controlling the valve most recently identified as the meter-in valve to maintain a first pressure setpoint when the actuator is in a passive state and to maintain a second pressure setpoint when the actuator is in an overrunning state.

A Control Valve Compensation System for producing both a pre-compensated and a post-compensated load sensing hydraulic directional control valve module, wherein both configurations use the same components except for a sliding compensating component. The Control Valve Compensation System generally includes a hydraulic directional control valve housing which is adapted to be easily-interchangeable between a load sensing pre-compensated pressure configuration and a load sensing post-compensated pressure configuration by simply removing and replacing a different compensator assembly within the housing. The compensator assembly is adapted to direct oil flow through the housing while simultaneously providing compensation for the valve function. Directional valve assemblies may be provided, with the valve assemblies functioning to provide post-compensated functions, pre-compensated functions, and mixed pre- and post-compensated functions. These directional valve functions can be re-configured in the field by simply swapping the compensator assemblies to produce the desired functionality of the end-user at that particular time.

The invention relates to a discharge pressure scale (30) consisting of at least one valve housing (41) having at least three fluid connection points in the form of a functional connector (A), a return flow connector (T) and a control connector (28), wherein a valve piston (52) is guided such that it moves longitudinally against the effect of an energy accumulator (42), moving from a respective opening or regulating position, against a valve seat (94), into a closed position, wherein the control (28) and return flow connectors (T) are separated from one another, characterised in that the fluid pressure present at the control connector (28) can be guided onto a pressure-active surface (A.sub.1*) of the valve piston (52) by means of a pressure compensation device (70) in such a way that it moves into its respective opening or regulating position in a pressure-compensated manner due to the force of the energy accumulator (42).

1. Valve and valve device comprising a valve of that type. 2. The invention relates to a valve comprising a valve housing (33), which has at least one service connection (A, B), a pressure supply connection (P) and a return connection (T) and in which valve housing (33) a control slide (STS) is guided so as to be movable longitudinally in order to control these individual connections. The valve is characterised in that the supply pressure, which is applied to the pressure connection (P) in order to control a consumer (10, 12) connected to the service connection (A; B), is guided across at least one control side (56) of the control slide (STS) via an orifice plate (54) and a control channel (50), the control side (56) being positioned in a control chamber (58) in the valve housing (33) such that it can move and the control chamber (58) being connected to the return connection (T) via an additional orifice plate (59).

A hydraulic system includes first and second valve assemblies connected to a common pump. The first valve assembly includes a main valve housed inside a manifold. A pressure compensator valve maintains a constant pressure drop across a variable orifice of the main valve. A pressure limiter valve is in communication with the main valve and the pressure compensator valve, and allows an actuator connected to the first valve assembly to operate independently of the second valve assembly so that fluid flow to a work port of the first valve assembly is not interrupted by operation of the second valve assembly.