Parker-Hannifin Corporation

Gregory Thomas Coolidge

Brian B Slattery

Kurt Boey

An example pressure compensator valve includes: a compensator spool; a first piston coupled to a distal end of, and axially-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.

Valve with an adjustable flow sharing pressure compensator

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.

Directional control valve

An example valve includes: a valve body defining a bore, an inlet port, an outlet port, and a signal cavity; a spool movable in the bore to shift between a first position and an intermediate position, where the spool has a first end and a second end, where the outlet port is fluidly connected to the second end, where the valve body defines a spring cavity adjacent the first end of the spool to house a spring, where the first end is subjected to a load-sense pressure signal, and where when the spool is in the first position, the spool disconnects the inlet port from the outlet port and connects the inlet port to the signal cavity; and a valve actuator that, when activated, connects the signal cavity to the second end of the spool to move the spool in the bore from the first position to the intermediate position.

Hydraulic control valve with controlled flow and valve safety disable

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.

A hydraulic valve assembly includes an inlet; an outlet; a pressure compensator upstream of the inlet; and a pressure limited flow priority boost valve spool movable between a first position and a second position and comprising an outer spool body and an inner spool body. The outer spool body includes deadhead meter notches disposed such that, in the first position, the spool closes fluid communication between the inlet and the pressure compensator, and such that, in the second position, the spool opens fluid communication between the inlet and the pressure compensator. The inner spool body is movable relative to the outer spool body and is configured to open fluid communication between the inlet and the outlet so as to bypass the compensator. The flow between the inlet and the compensator is a reduced pilot flow.

Pressure limited flow priority boost

A valve includes a pressure limiting flow spool disposed in a valve body. The spool is movable in a first direction from a first position to a second position and in the first direction from the second position to the third position. The valve includes an inlet and a first outlet. The first position is a closed position preventing flow from the inlet to the first outlet, the second position is a maximum flow position having a maximum flow capacity from the inlet to the first outlet, and the third position is a pilot flow position having a reduced flow capacity from the inlet to the first outlet smaller than the maximum flow capacity.

Pressure limited flow spool

A working valve section for a sectional fluid control valve comprising a valve section housing having a substantially planar surface for being attached to an adjacent valve section housing; a main control spool bore () extending into the housing substantially parallel to the planar surface; a compensator spool bore () extending into the housing substantially parallel to the planar surface, the compensator spool bore being spaced from the main control spool bore; a first relief slot () extending across the planar surface substantially coextensive with the main control spool bore; and a second relief slot () extending across the planar surface substantially coextensive with the compensator spool bore.

Hydraulic sectional control valve with multiple relief slots

A hydraulic control valve assembly (), method and system, characterized by control valves () each having a variable metering orifice; a compensator () that controls flow of fluid from the variable metering orifice to a work port (A,B) in response to a differential in pressures acting on opposite first and second sides of the compensator, wherein a first side receives a pressure at the downstream side of the variable metering orifice; a load sense passage () providing a load sense pressure; and a differential pressure controller () having a first inlet connected to a pump supply port and a second inlet connected to the load sense passage, the controller having a first operational mode in which load sense pressure at the second inlet is supplied to an outlet of the controller and a second operational mode in which flow from the first inlet is metered to the outlet of the controller to provide a differential control output pressure, and wherein an outlet of the differential pressure controller is connected to a pump control port and/or to the second side of the pressure compensating valve of at least one of the control valves.

Pressure compensated hydraulic system having differential pressure control

An assembly of valve sections includes an inlet section, an outlet section, a working section, and a working section. The working section is a conventional pressure compensated working section. The working section includes a directional control valve, a pressure compensator valve, and a pressure limiter valve. The valves are of integral construction, such that each is an essential part to complete the other. The pressure compensator valve includes a pressure compensator spool movable between an opened position and a closed position in response to a pressure differential across the spool. The pressure limiter valve includes a pressure limiter spool that moves to an open position to change the pressure differential and close the pressure compensator valve when a selected limit pressure is reached.

Hydraulic valve with pressure limiter

A control valve comprises a valve body having a fluid inlet and at least one work fluid outlet for supplying pressurized fluid to the fluid operated device. A valve member is movable in the valve body in a first direction from a null position to a full flow or open position for supplying flow of pressurized fluid from a feed passage to a work fluid outlet. The valve member has a load sense signal shaping device that provides for initial flow from the feed passage to the work fluid outlet through a metering orifice during movement of the valve member from the null position to the full flow open position so as to shape an initial boost pressure signal.

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Elyria, OH, United States of America

Gregory Thomas Coolidge