An example valve includes: a piston movable between a neutral position and an actuated position, wherein in the neutral position: a second port of the valve is fluidly coupled to a first port, and a third port is fluidly decoupled from the second port; a solenoid actuator sleeve movable between an unactuated state and an actuated state, wherein in the actuated state, the solenoid actuator sleeve allows pilot fluid to apply a fluid force on a piston in a distal direction; a first feedback spring; and a second feedback spring disposed in series with the first feedback spring, wherein the first feedback spring and the second feedback spring cooperate to apply a biasing force in a proximal direction on the piston against the fluid force, wherein the piston is configured to move to the actuated position based on a relationship between the fluid force and the biasing force.

A new means of achieving a valve float position in a closed centered hydraulic control valve. The valve has a main spool position whereby pressure compensator load sense control pressure is drained to tank through the main spool. Secondly, a pin acts on the pressure compensator to prevent the main pump flow from reaching the main section spool. Finally, the new spool position adds a connection from the consumer to tank, enabling a float position.

A system for compensating for drift or movement of a hydraulic actuator connected to a machine's boom or similar elongate member that is caused, at least in part, by damping of mass-induced vibration. The system comprises a processing unit and a plurality of sensors operable to collect data from a control valve connected to an actuator's load holding chamber and to calculate additional volume present therein due to vibration damping. Using the calculated additional volume, the processing unit determines a hydraulic fluid flow rate appropriate to substantially reduce or eliminate the additional volume. The processing unit combines this flow rate with the hydraulic fluid flow rate necessary to cause operation of the actuator in response to the machine's operator input, and provides signals to the control valve causing actuation of the valve to output hydraulic fluid to the actuator at a rate equal to the combined flow rates.

An example valve includes: a piston movable between a neutral position and an actuated position, wherein in the neutral position: a second port of the valve is fluidly coupled to a first port, and a third port is fluidly decoupled from the second port; a solenoid actuator sleeve movable between an unactuated state and an actuated state, wherein in the actuated state, the solenoid actuator sleeve allows pilot fluid to apply a fluid force on a piston in a distal direction; a first feedback spring; and a second feedback spring disposed in series with the first feedback spring, wherein the first feedback spring and the second feedback spring cooperate to apply a biasing force in a proximal direction on the piston against the fluid force, wherein the piston is configured to move to the actuated position based on a balance between the fluid force and the biasing force.

Systems and methods for auto-commissioning first and second valve assemblies associated with an actuator in an electro-hydraulic system are disclosed. In one method, a controller performs an automatic test protocol to determine a bulk modulus over fluid volume parameter used by the controller to control the valve assemblies. In one aspect, the test protocol can include pressurizing each side of the actuator to two different pressures with one of the first and second valve assemblies and blocking the other side of the actuator with the other of the first and second valve assemblies. The bulk modulus over fluid volume parameter for each valve assembly can be calculated based on recorded fluid pressures at the actuator and consumed flow at the first and second valve assemblies.

Hydraulic pressure compensator units and hydraulic systems incorporating hydraulic pressure compensator units. The pressure compensator units include a main valve body defining a central axis and a first central passage, a compensation valve member positioned in the first central passage and defining a second central passage, the first central passage being in selective fluid communication with a port of hydraulic actuator. A load sense check component is positioned within the second central passage and adapted to move in a first axial direction to selectively open a fluid communication between a pump output and a load sense line. A reverse flow check component is positioned within the second central passage and adapted to move in a second axial direction opposite the first axial direction to selectively open a fluid communication between the hydraulic actuator and a tank line.

An example valve section includes: a valve body configured to be fluidly coupled to the source and the actuator; a spool movable in the valve body intermediate the source and the actuator; a pressure compensator valve disposed upstream from the spool and configured to regulate flow received from the source, where the valve body defines (i) a first passage disposed upstream from the spool and configured to fluidly couple the pressure compensator valve to the spool, and (ii) a second passage disposed downstream from the spool and configured to fluidly couple the spool to the actuator; and a counterbalance valve disposed in the second passage downstream from the spool, where the counterbalance valve is opened to permit flow therethrough from the actuator to the spool in response to a pilot pressure derived from the first passage when the spool is shifted from a neutral position.

A hydraulic system includes a supply line, at least one implement-based control valve, an implement-based pressure regulating valve, and a load sensing circuit. The implement-based control valve(s) is fluidly coupled to the supply line and configured to regulate a flow of the pressurized hydraulic fluid supplied through at least one downstream actuator line to at least one hydraulic actuator of the implement. The implement-based pressure regulating valve is fluidly coupled to the supply line upstream of the control valve(s) and configured to regulate a fluid pressure to be equal to or greater than a minimum fluid pressure. The load sensing circuit is fluidly coupled to the pressure regulating valve and provides a line or load pressure to the pressure regulating valve. The pressure regulating valve is configured to regulate the supply of the pressurized hydraulic fluid based on the line pressure.

A new means of achieving a valve float position in a closed centered hydraulic control valve. The valve has a main spool position whereby pressure compensator load sense control pressure is drained to tank through the main spool. Secondly, a pin acts on the pressure compensator to prevent the main pump flow from reaching the main section spool. Finally, the new spool position adds a connection from the consumer to tank, enabling a float position.

A multi-control hydraulic circuit supplies receivers with hydraulic fluid delivered by a pump with an output controlled by the pressure of a control line depending on a load pressure of the receivers, and delivers the hydraulic fluid at a regulated pressure. The hydraulic circuit consists of hydraulic modules each associated with a receiver having a distributor which regulates the variable output supplying the receiver via a pressure compensator connected at its inlet to the outlet of the variable choke of the distributor, and at its outlet. The plunger manages the connection between its inlet and its outlet. The pressure compensator has a fluid link equipped with a choke and connects the outlet to the control line, irrespective of the position of the plunger.