Exemplary control valves that may be configured as a load sense, closed-center, and/or open-center valve. The control valve may include optional individual valve force sensing to potentially allow an operator to smoothly operate devices operating on low-load work ports even when a variable displacement pump is inducing pressure to operate a device connected to a high-load work port of a separate valve or worksection in the same stack. This optional force sensing may be employed on any or all worksections associated with any valve stack, and may further be included on one or both workports for any given worksection. Each worksection may include parallel and variable paths of fluid supplied by the pump. Also, flow priority to one or more worksections or external valves in a corresponding hydraulic system is optional and can be customized using the variable flow path and a corresponding fixed restriction.

An energy saving directional-control valves (2-position and 3-position) are configured with standard manual override functionality and with the same steady-state input-output behavior as each respective standard/non-energy saving directional-control valve. This allows a standard non-energy saving valve to be replaced with an energy saving valve without reconfiguring the external electrical and manual override command logic.

[Object] To provide a compact, rationally designed, dual 4-port electromagnetic valve that is an electromagnetic valve having functions of two 4-port valves.

[Solution] A dual 4-port electromagnetic valve includes two spools (8a, 8b) slidable independently of each other in a valve hole (7); two pilot valves (4a, 4b) that drive the two spools, respectively; a main supply port (P) that communicates with the valve hole (7) at a position where the two spools face each other; first and second output ports (A1, A2) that communicate with the valve hole (7) on two respective sides of the main supply port (P), first and second discharge ports (E1, E2) that communicate with the valve hole (7) on two respective outer sides of the output ports (A1, A2), third and fourth output ports (B1, B2) that communicate with the valve hole (7) on two respective outer sides of the discharge ports (E1, E2), and first and second supply ports (P1, P2) that communicate with the valve hole (7) on two respective outer sides of the output ports (B1, B2). The main supply port (P) and each of the first and second supply ports (P1, P2) communicate with each other.

A servovalve (15) comprising a motor (16), a motor bias mechanism (20), a first stage valve member (22) adapted to be moved from a first position to a first off-null position, a second stage member (29) adapted to be moved from a first position to a second position with movement of the first valve member (22), a transfer link (34) acting between the first (22) and second (29) valve members, an eccentric drive member (35) acting between the motor (16) and the transfer link (34), the transfer link (34) and drive member (35) configured such that selective movement of the motor (16) causes the transfer link (34) to move the first valve member (22), movement of the first valve member (22) causes the second valve member (29) to move, and movement of the second valve member (29) causes the transfer link (34) to move the first valve member (22) from the first off-null position back to the null position.

A latching solenoid assembly is provided which includes a solenoid actuator. A housing is also provided which has an axial passage. An intermediate piston is moved by the solenoid actuator. A reaction member is also placed within the housing axial passage spring biased by a transfer spring from the intermediate piston. The housing has a latching port allowing pressure to latch the intermediate piston in position to set the force which is transmitted to the reaction member.

Systems and methods for electrohydraulic valve calibration are provided. In one aspect, a calibration circuit includes a calibration conduit isolated from a supply conduit, a first calibration orifice configured to provide fluid communication between the calibration conduit and a fluid source, and a second calibration orifice arranged in series with the first calibration orifice. The second calibration orifice is on a spool of a electrohydraulic control valve and is configured to selectively provide fluid communication between the calibration conduit and a low pressure source. The calibration circuit further includes a pressure sensor configured to measure a pressure in the calibration conduit between the first calibration orifice and the second calibration orifice. The second calibration orifice is isolated from the at least one workport of the electrohydraulic control valve.

A redundant control system for a vehicle includes: one or more actuator housings; a plurality of actuator pistons coupled to the actuator housings, each of the actuator pistons mechanically coupled to one another and a common output device; a plurality of primary stages coupled to the actuator housings, each of the primary stages operatively coupled to move a respective actuator piston relative to at least one of the actuator housings, and each of the primary stages functioning independent of any other primary stage when the control system is operating in a flight-operation mode; and an auxiliary stage operatively coupled to move a first of the plurality of actuator pistons relative to at least one of the actuator housings when the control system is operating in a ground-operation mode, with each of the plurality of primary stages being responsive to movement of the first actuator piston by the auxiliary stage.

A valve includes a solenoid with a chamber housing a pin that actuates when the solenoid is energized. The valve also includes a spool housed within a sleeve. The sleeve includes a supply section with a supply port in communication with a supply source and a tank section with a tank port in communication with a reservoir. The spool includes a body including a first passage receiving fluid from the supply source when an opening for the first passage aligns with the supply port. When the solenoid is energized and the opening for the first passage aligns with the supply port, fluid from the supply source (i) applies a force to the spool body in a direction of actuation by the pin and (ii) flows to a second passage within the valve.

A hydraulic system (600) and method for reducing boom dynamics of a boom (30), while providing counter-balance valve protection, includes a hydraulic actuator (110), first and second counter-balance valves (300, 400), first and second independent control valves (700, 800), and first and second blocking valves (350, 450). The actuator includes first and second corresponding chambers. In a first mode, the second counter-balance valve is opened by the first control valve, and the first counter-balance valve is opened by the second control valve. In a second mode, at least one of the counter-balance valves is closed. A meter-out control valve (800, 700) may be operated in a flow control mode, and/or a meter-in control valve (700, 800) may be operated in a pressure control mode. Boom dynamics reduction may occur while the boom is in motion (e.g., about a worksite). By opening the counter-balance valves, sensors at the control valves may be used to characterize external loads. The control valves may respond to the external loads and at least partially cancel unwanted boom dynamics. The system may further detecting faults in actuators with counter-balance valves and prevent any single point fault from causing a boom falling event and/or mitigate such faults.

A method of cooling or heating a plurality of computer processor heat sources, such as processors in a data center or the like, is disclosed with individual sources having a control valve associated therewith. Individual heat sources are in communication with a supply of a coolant fluid and individual control valves have an inlet for receiving coolant fluid from its respective computer processor heat source reflective of the heat source temperature. The control valve has a chamber with an inlet that receives coolant, and an outlet. A valve member within the chamber is movable in response to changes in temperature of the coolant fluid within the chamber between a closed position and an open position. The valve member is of a material that changes shape in response to changes in temperature. The coolant is carbon dioxide (CO.sub.2) that is in its supercritical state as it passes through the heat sources.