Abstract: A valve for controlling a hydraulic cylinder on a work machine may include a raising position configured for placing a pump in fluid communication with a cap end of the hydraulic cylinder. The valve may also include closed center position configured for closing off fluid communication to the cap end line and the rod end line. The valve may also include a lowering position configured for placing the pump in fluid communication with the rod end of the hydraulic cylinder. The valve may also include a snubbing position configured for placing the cap end in restricted flow fluid communication with the tank and for placing the rod end in restricted flow fluid communication with the tank.

Abstract: A hydraulic valve assembly having a regeneration circuit, where the hydraulic valve assembly is switchable between a regenerative mode and a non-regenerative mode as the valve assembly supplies fluid to operate a hydraulic device. The hydraulic valve assembly may be automatically switchable between the regenerative mode and the non-regenerative mode, such as by utilizing a pressure control valve in the hydraulic circuit that is activatable at a predetermined pressure setpoint, or by utilizing a variable pressure reducing valve that actuates a spool in the hydraulic circuit. In other embodiments, the hydraulic valve assembly may be manually switchable between the regenerative mode and non-regenerative mode by utilizing a valve member operatively coupled to a solenoid in cooperation with one or more check valves in the regeneration circuit.

Abstract: A motor, a driving circuit thereof and a driving method thereof are provided. The motor driving method includes: during a motor starting stage, when a detected rotor magnetic field is a first polarity and a polarity of an AC power source is positive, or the detected rotor magnetic field is a second polarity and the polarity of the AC power source is negative after a zero voltage crossing point of the AC power source, instantly sending a trigger pulse to a controllable bidirectional AC switch connected in series with a motor winding at both ends of the AC power source; during a motor operating stage, after the zero voltage crossing point of the AC power source, sending a trigger pulse to the controllable bidirectional AC switch after a delay time after the zero voltage crossing point. This method can provide a large torque during the motor starting stage.

Abstract: The device has an internal distributor to be disposed in a casing portion (10A), and has a body (15) that has an outside axial face (15B) provided with two grooves (17, 19) respectively for feed and for discharge. The distributor has distribution ducts (23A, 23B, 23C) that open out in a distribution radial face and a cylinder capacity selector that has a slide (50) suitable for being moved in an axial bore (53) for connecting the distribution ducts to one or the other of the grooves. The device further has a control chamber (52) provided between a first end wall (15?) of the bore and the first end (50A) of the slide, and an opposing spring (55) disposed in a return chamber (52?) situated at the second end (53?) of the bore and closed, at the end closer to the distribution face (15A), by a second end wall (55?) of the distributor.

Abstract: A working machine control system includes a split flow type fluid pressure pump configured to discharge a working fluid from a first discharge port and a second discharge port, and a lower pressure selection circuit configured to select and communicate with a working fluid of lower pressure among a working fluid on the downstream of a first operation valve of a first neutral passage in a first circuit system to which a working fluid discharged from the first discharge port is supplied, and a working fluid on the downstream of a second operation valve of a second neutral passage in a second circuit system to which a working fluid discharged from the second discharge port is supplied. The fluid pressure pump is adjusted in such a manner that the lower the pressure of the working fluid selected by the lower pressure selection circuit is, the more a discharge flow rate is increased.

Abstract: The invention relates to a hydraulic valve device (1) including a high pressure connection (P?) and a low pressure connection (T?); at least one motor port connection (A?) that is connectable to a motor port (A) on a hydraulic motor (M), preferably a hydraulic cylinder; a flow control valve (F), which is arranged between the high pressure connection (P?) and the motor port connection (A?) and which includes a flow opening (18) that is adjustable between a fully closed position and a fully open position; and a pressure regulator (R) that is arranged between the high pressure connection (P?) and the flow regulating valve (F), wherein a regulator pressure (PR) that acts at a first connection point (3) between the pressure regulator (R) and the flow regulating valve (F) acts on the pressure regulator (R) via a first control conduit (4) to close the same.

Abstract: The present invention relates to a hydraulic drive which comprises a hydraulic motor having a first hydraulic connector and a second hydraulic connector, wherein the pressure applied at the first hydraulic connector of the hydraulic motor and the pressure applied at the second hydraulic connector of the hydraulic motor are each separately adjustable.

Abstract: A load sensing electric-proportional multi-way valve. The technical problem to be solved by the present application is to provide a load sensing electric-proportional multi-way valve, enabling individual loops to operate with different loads, to save energy and reduce the environmental pollution. The technical solution for solving the technical issue includes as follows. A load sensing electric-proportional multi-way valve includes a main oil passage connected with two gear pumps P1 and P2, a lifting loop connecting to the main oil passage via an electric-proportional pressure compensated flow control valve, and an inclining union and an attachment union connecting to the main oil passage via an electric-proportional pressure compensated flow control valve, a logic direction valve connected to the main oil passage, a proportional motor-driven overflow valve and a two-way solenoid valve connecting to an oil inlet port of the logic direction valve.

Abstract: A vehicle transmission pressure regulator valve for regulating oil flow to a torque converter clutch from a pump in a lubrication circuit of the transmission wherein the valve includes a plurality of spaced annular lands integrally formed with a core body of the valve and wherein at least an outermost regulation line dump circuit control land and a second intermediate torque converter feed control land are tapered inwardly toward the core body and in a direction of an innermost pressure regulator balance land so to dynamically regulate flow into the regulation dump line and the torque converter circuit feed circuits due to the tapered surfaces of the two valve lands and wherein an additional converter assist spring is seated within an inner end of the valve so as provide a continuous force urging the valve toward and open position within the valve seat bore of the transmission.

Abstract: A servo actuator system and method of operating the same includes a dual acting actuator comprising an actuator body and a movable member movable in the actuator body to define a first and second chamber on each side of the movable member. A first port is fluidly coupled to the first chamber and a second port is fluidly coupled to the second chamber. A fluid pump having a return is provided. A proportional valve assembly is fluidly coupled to the fluid pump, return and the first and second ports. The proportional valve assembly includes a plurality of metering orifices. A controller is operably coupled to the proportional valve assembly to control the plurality of metering orifices to generate a load vector having magnitude and direction and wherein an actual position of a movable member in an actuator body is indeterminate.

Abstract: A hydraulic switching mechanism for the mobile hydraulics of, for example, hydraulic excavators, with a valve block, with electrohydraulically activatable valve units for controlling the movement of a working cylinder whose cylinder chambers can be selectively connected to a pump connection for hydraulic fluid, to a tank connection or to one another, and with pre-control valves for activating the valve units, wherein the hydraulic switching mechanism, by means of separate tank valve units and pump valve units, and also a suitable pre-control system, makes it possible to achieve a directional control valve function and a directly controlled and superimposed pre-controlled lowering braking function, a maximum pressure safeguarding of the cylinders and a proportional throttle valve function for the controlled displacement under negative load forces in the direction of movement and braking in an emergency; and mobile hydraulic machines having such a hydraulic switching mechanism and also to valve units therefor.

Abstract: Hydraulic valve arrangements may be assembled to provide pre-compensation or post-compensation using the same chassis body. A first type of main spool is disposed in a main passage and a first type of pressure compensator spool is disposed in a compensator passage to provide pressure pre-compensation. The first type of pressure compensator spool connects to a first pilot location and not to a second pilot location. A second type of main spool is disposed in the main passage and a second type of pressure compensator spool is disposed in the compensator passage to provide pressure post-compensation. The second type of pressure compensator spool connects to the second pilot location and not to the first pilot location. The valve arrangement may be switched from pre-compensation to post-compensation (or vice versa) by switching out the main spool and pressure compensator spool without making any other changes to the chassis body.

Abstract: An electric drive unit for a construction machine is capable of increasing the operating time of the construction machine. The electric drive unit has an electricity storage device, a hydraulic pump of variable displacement type which is driven by a motor/generator, a regulator which performs variable control on the displacement volume of the hydraulic pump, a bidirectional converter which performs variable control on the revolution speed of the motor/generator, and an LS control device which controls the regulator and the bidirectional converter so that LS differential pressure Pls equals a target value Pgr. The bidirectional converter performs regeneration control for converting the inertial force of the rotor of the motor/generator into electric power thereby charging the electricity storage device when the revolution speed of the motor/generator is decreased in response to an excess of the LS differential pressure Pls over the target value Pgr.

Abstract: This disclosure provides for pressure limiting a hydraulic system to a desired pressure value by a particular circuit by controlling and closing the compensator when the desired pressure setting is achieved. Closing the compensator will reduced the pressure head and flow in the circuit resulting in improved efficiency. One illustrated embodiment of the disclosure provides a relief valve in the pilot signal for a compensator. The method relates to limiting the pressure on an open side of the compensator, such that the pressure on the other side closes the compensator thereby limiting the pressure and also flow in the hydraulic circuit. In other words, the pressure on the open side is limited by the relief valve. Thus, the pressure on the other side increases thereby regulating the flow and pressure through the compensator.

Abstract: An energy-saving valve includes a spool-driving unit which changes the position of a spool to a position at which compressed air is discharged from a first output port without pressure control and includes a pressure control unit which changes the position of the spool to a position at which compressed air is discharged from a second output port in a predetermined pressure level due to pressure control. The pressure control unit includes a pressure control piston, a pressure-receiving surface which enables air pressure in the second output port to act on the pressure control piston, a cylinder chamber, a pressure control channel, and an elastic member which applies biasing force to the pressure control piston in a direction opposite to the action of air pressure on the pressure-receiving surface to determine pressure.

Abstract: A poppet valve assembly includes a body and first and second check valves. The body includes opposing first and second axial end portions. The first end portion has a first circumferential surface, a first end surface, and a tapered surface, which seals with a main valve seat. The second axial end portion defines at least one metering slot. The body defines first and second internal passages. The first internal passage includes an opening in the first end surface, is in fluid communication with one of the metering slots, and has a first check valve seat. The second internal passage includes an opening in the first circumferential surface, is in fluid communication with one of the metering slot, and has a second check valve seat. The first and second check valves are disposed in the respective internal passages and are adapted for sealing engagement with the respective check valve seats.

Abstract: An independent metering valve (IMV) assembly is disclosed that includes a metering stem including an inlet. The IMV assembly also includes a hydro-mechanical control valve in communication with a fluid source and the inlet. The control valve also including a spool with a closed end and an open end. The control valve includes a biasing member that biases the control valve or spool towards an open position thereby establishing communication between the fluid source and the inlet. The control valve also including a load signal line providing communication between an outlet of the control valve upstream of the inlet and the closed end of the spool. Wherein high pressure in the load signal line allowing the control valve to move towards a closed position thereby overcoming bias of the biasing member and reducing flow to the inlet during a high pressure condition.

Abstract: A method for controlling fluid flow. A valve system may be kept in an open state in response to a fluid being at a selected level of pressure at any of a plurality of ports in a valve. The valve system may be for the valve, and the valve may comprise a housing, the plurality of ports on the housing, and the valve system located inside the housing. The valve system may be configured to be in a closed state when an absence of the selected level of pressure is present at all of the plurality of ports and in the open state when the selected level of pressure is present at any of the plurality of ports. The valve system may be kept in the closed state in response to an absence of the fluid being at the selected level of pressure at all of the plurality of ports.

Abstract: A hydraulic system is disclosed having a pump configured to draw low-pressure fluid from one of a first and second passage, and discharge fluid into the other of the passages. The hydraulic system may also have an actuator coupled to the pump via the passages, a charge circuit, a makeup valve movable to pass fluid from a higher pressure one of the first and second passages, and a force modulation control valve disposed between the makeup valve and the charge circuit. The force modulation control valve may be movable between a first position at which fluid passed from the higher-pressure one of the first and second passages is directed into the charge circuit, and at least a second position at which fluid from the higher-pressure one of the first and second passages is directed into a lower-pressure one of the first and second passages and blocked from the charge circuit.

Abstract: A compressed gas operated instrument incorporating a connector for a compressed gas cartridge to which the compressed gas cartridge is connectable in sealed manner by means of a supply channel for the compressed gas flowing out of the compressed gas cartridge is provided which incorporates a regulating valve in the supply channel for governing the compressed gas stream through the supply channel. The regulating valve comprises a valve body which is sealed in a valve chamber with respect to a wall of the valve chamber by means of a first seal and is mounted in the valve chamber in displaceable manner. The valve body is connected on the upstream side thereof in sealed manner to a connector element by means of a second seal and also be displaceable with respect to the connector element by displacement thereof in the valve chamber.

Abstract: The invention discloses a valve arrangement for supplying pressure medium to a hydraulic load (2) having a directional valve (8), which has an inflow measuring diaphragm (10, 12) and a directional part (14, 16) flowing in the flow direction. The directional valve is associated with an individual pressure scale (18). In a return from the load, a load-lowering valve (44, 46) is provided, to which a pilot pressure is applied in the opening direction. According to the invention, said pilot pressure is tapped in channel between the pressure scale and the directional part.

Abstract: A pressure compensated electromagnetic proportional directional flow control valve of the present invention integrally includes: an electromagnetic proportional directional flow control valve configured to be driven by a solenoid; and a pressure compensated valve configured to carry out pressure compensation of a flow rate controlled by the electromagnetic proportional directional flow control valve. A pressure compensation spool moves so as to balance forces of a spring, a first pressure chamber, and a second pressure chamber. With this, the pressure compensation for maintaining a constant pressure difference between an upstream side and a downstream side of a first variable aperture can be carried out, and a surplus liquid of a liquid flowing from a liquid-pressure supply port to a derivation port can flow out from a branch port to outside.

Abstract: A valve arrangement has an adjustable control valve (10) including a control slide (12) for actuating at least one consumer connection (A, B) and an LS control line. The differential pressure of two actuating pressures (xa, xb) serves for the actuation of the control slide (12). Since the actuating pressures (xa, xb) also actuate a logic valve, which in turn influences an additional valve, and/or actuates a pressure compensator connected upstream to the control valve (10), the difference of the two actuating pressures (xa, xb) initially displaces the control slide of the control valve. The higher or the lower of the two actuating pressures (xa, xb) either actuate the further valve in the form of the additional valve, and/or influences the pressure compensator.

Abstract: A hydraulic valve device, especially an LS current regulating valve, includes a fluid connection arrangement (10). As the respective control device (14) associated with a useful connection (A) comprises a control slide (16) upstream of which a pressure balance (18) is mounted in the fluid direction towards each useful connection (A, B), any system vibrations occurring in the load sensing regulating circuit can be better controlled and the respectively connected hydraulic consumer can be subjected to a constant current regulation.

Abstract: A hydraulic system for a machine is disclosed. The hydraulic system has a source of pressurized fluid and a fluid actuator with a first chamber. The hydraulic system also has a first valve configured to selectively fluidly communicate the source with the first chamber. The first valve further includes a first element movable between a flow passing, at which fluid from the source flows to the first chamber, and a flow blocking position, at which fluid from the source is blocked from the first chamber and a second element configured to selectively drain a control passageway associated with the first element to cause the first element to move. The hydraulic system further has a proportional pressure compensating valve configured to control a pressure of a fluid directed between the source and the first valve dependent upon the pressure of the control passageway.

Abstract: The invention relates to the field of load sensing, flow sharing directional control valves for controlling an operating machine, such as an excavator. The directional control valve of the present invention is particularly characterized by the addition of at least one element (E4) wherein the provision of a bore (16) and the replacement of components (30), (50), (M1) with a compensator (9), having a spring (14) operating on one side thereof (9a), and a piston/load sensing signal selector (8) impart to this single element (E4) the feature of non participating in flow-rate reduction under saturation conditions, while preserving the feature of maintaining a constant flow-rate to the user, irrespective of the variation of the load.

Abstract: An LS control system is disclosed that includes an inlet metering orifice and a pressure compensator, via which the pressure drop across the inlet metering orifice may be held constant. The signalling pressure that acts on the pressure compensator in the opening direction may be varied as a function of the displacement in order to prevent the system from oscillating if a negative load should occur.

Abstract: A hydraulic circuit for a hydraulic working machine is composed of a main pump 21, a boom cylinder 11 arranged for extension or contraction by pressure oil from the main pump 21, a directional control valve 22 for controlling flows of pressure oil to be fed from the main pump 21 to a bottom chamber 11a and rod chamber 12b of the boom cylinder 11, a control unit 23 for performing a change-over control of the directional control valve 22, a pilot pump 24, a jack-up selector valve 25 for controlling a flow of pressure oil delivered from the pilot pump 24, a flow control valve 26 connected on an upstream side of the directional control valve 22 to a meter-in port of the directional control valve 22 such that the flow control valve 26 can be changed over by the jack-up selector valve 25, and a center bypass selector valve 27 connected on a downstream side of the directional control valve 22 to a center bypass port of the directional control valve 22 such that the center bypass selector valve 27 can be changed over

Abstract: A railway brake cylinder includes a body (11?); a piston (13?) mobile relative to the body (11?) to act on a brake linkage and delimiting with the body (11?) a pressure chamber (10?) adapted to be supplied by a pneumatic pressure agent source; an auxiliary actuating member (26?) mobile relative to the body (11?) and the piston (13?), mechanically connected to manual operating elements to cause it to occupy either a rest position in which it is away from the piston (13?) or a pushing position in which it is in contact with the piston (13?); two orifices (73?, 51?) in fluid communication with the chamber (10?) and the atmosphere, respectively; and selective connecting elements (28?) between the two orifices (73?, 51?), the elements (28?) being mechanically connected to the auxiliary actuating member.

Abstract: A digital hydraulic controller has at least two rows of valve elements: one can connect a supply line to a controller output, the other can connect the controller output to an outlet line. The valve elements of each row are connected in parallel and are switchable individually or simultaneously in different combinations with each other and have different flow cross sections. The valve element with the smallest flow cross section is present twice in the row. A system unit has a differential cylinder and a digital hydraulic controller with four rows of valve elements, two of which are, with their common controller output, connected to the one pressure chamber of the differential cylinder, while the other two rows of valve elements are, with their common controller output, connected to the other pressure chamber of the differential cylinder. The differential cylinder can be used as a precisely adjustable linear actuator.

Abstract: An LIFD valve assembly has a pressure balance device a pressure balance slide of which is urged in the opening direction by a pressure downstream of a metering aperture and in the closing direction by a control pressure preferably corresponding to the highest load pressure of a plurality of consumers, and a load pressure downstream of the metering aperture is reportable to a line via the pressure balance device, and a load-maintaining device that can be put in a closing position, in which position a pressure medium flow path from a consumer to the metering aperture is blocked. The pressure balance slide is embodied in divided fashion, with an upper part and a lower part, wherein the latter is guided on the upper part, and determines the pressure balance device throttle cross section with a pressure balance control edge and embodies a closing body of the load-maintaining device.

Abstract: A valve seat 20 is arranged between the supply circuit 8 and a downstream circuit 18. A valve body 21 blocks a fluid flow between the supply circuit 8 and the downstream circuit 18 by contacting the valve seat 20. The valve body 21 connects the supply circuit 8 to the downstream circuit 18 for supplying the fluid to the downstream circuit 18 by separating from the valve seat 20. A through hole 24 extends through the valve body 21 and thus defines a part of the supply circuit 8. The through hole 24 is defined in such a manner that the fluid that has flowed from the through hole 24 proceeds between the valve seat 20 and the valve body 21 and is thus supplied to the downstream circuit 18. The valve body 21 is formed in such a manner that a pressure receiving area at an upstream side of the through hole 24 is smaller than a pressure receiving area at a downstream side of the through hole 24.

Abstract: Disclosed is a lifting gear valve arrangement for controlling a double-action lifting gear or an add-on unit with a continuously adjustable directional control valve and with an individual pressure compensator via which a pressure medium volume flow to and from a lifting cylinder of the lifting gear can be controlled. A proportionally adjustable pressure limiting valve is provided in the pressure medium flow path between an outlet connection of the directional control valve and a working connection of the lifting gear valve arrangement, via which the pressure inside this area can be limited to a maximum value. The adjustment of the pressure limiting valve is preferably performed as a function of the operating states of the lifting gear or of the type of add-on unit.

Abstract: An apparatus for preventing noise from occurring due to cavitation in a power steering pump during low temperature start-up includes the addition of a multi-passage orifice element for adding wetted surface resistance to high viscous fluid flow downstream from a single passage outlet orifice element of a fluid flow control device and upstream of an associated steering gear or steering assist valve.

Abstract: A flow control apparatus for heavy construction equipment is provided, which can prevent overspeed and abrupt operations of an actuator due to an excessive flow rate during an initial operation of the actuator when a composite work is performed by simultaneously operating an option device and another actuator, and can prevent the cut-off of hydraulic fluid supply to the option device due to an operation inability of a flow control valve when leakage of the hydraulic fluid occurs due to the increase of the temperature of the hydraulic fluid.

Abstract: A proportional pressure controller includes a body having inlet, outlet, and exhaust ports. A fill valve communicates with pressurized fluid in the inlet port. A dump valve communicates with pressurized fluid from the fill valve. An inlet poppet valve opens by pressurized fluid through the fill valve. An exhaust poppet valve when closed isolates pressurized fluid from the exhaust port. An outlet flow passage communicates with pressurized fluid when the inlet poppet valve is open, and communicates with the outlet port and an exhaust/outlet common passage. A fill inlet communicates between the inlet passage and fill valve, and is isolated from the outlet flow passage, exhaust/outlet common passage, and outlet and exhaust ports in all operating conditions of the controller.

Abstract: Actuator controller comprising a body (12) with an inlet port (14) coupled to a source of pressurized fluid and in flow communication with primary and secondary spool bores (16, 20); primary and secondary spools (60, 62); first and second cross flow ports (48, 52) communicating said primary and secondary spool bores, compression and expansion outlet ports (53, 54) for applying pressurized fluid to a return-biased actuator (110); and a venting outlet port (23); wherein return action of the working piston of the actuator is facilitated with aid of pressurized fluid already gained in the system.

Abstract: A supply passage, a discharge passage, an actuator passage, and a spool bore are defined in a housing. The spool bore accommodates a spool and communicates with the supply passage, the discharge passage, and the actuator passage. Load pressure detection circuit sections of load pressure detection circuit are provided in correspondence with two switch. Each of the load pressure detection circuit sections detects load pressure when the actuator passage is connected to the supply passage. Each load pressure detection circuit section is defined by a through hole provided in the housing and connected to the spool bore. Check valves are each arranged in a corresponding one of the load pressure detection circuit sections. This simplifies the configuration of each load pressure detection circuit 21 and saves the space for arranging the load pressure detection circuit 21., resulting in a relatively compact housing.

Abstract: An array of valve sections in a hydraulic system are connected to a supply line, a tank return line, and a load sense line. One valve sections includes a control valve with a metering orifice through which fluid flows from the supply line to a valve outlet. A load sense node is coupled by a load sense orifice to the load sense line. A load sense pressure limiter prevents pressure at the load sense node from exceeding a threshold level. A pressure compensator is connected in a fluid path between the valve outlet and one of the hydraulic actuators. The pressure compensator opens and closes the fluid path in response to pressure at the valve outlet and pressure at the load sense node, thereby governing the maximum amount of pressure that the respective valve section can apply to the hydraulic actuator.

Abstract: A ride control arrangement for a machine having a frame, a ripper, a hydraulic actuator operative to move the ripper includes at least one accumulator assembly, and a valve mechanism operatively disposed between the accumulator assembly and the hydraulic actuator to either block or allow fluid communication between the hydraulic actuator and the accumulator assembly. A ride control arrangement for a motor grader with an implement operated by a hydraulic actuator similarly includes at least one accumulator assembly selectively fluidly connected to the hydraulic actuator by way of a valve mechanism.

Abstract: A manual valve of a hydraulic pressure control system for an automatic transmission includes: a valve body including a first exhaust passage that includes an exhausting hole and an intake hole that are communicated with a drive range port in a neutral range, such that a transmission fluid, which is supplied from the drive range port when the vehicle is shifted from drive to neutral, is exhausted; and a hydraulic pressure exhaust control unit that is disposed in the exhaust hole so as to control an exhaust amount according to an exhaust pressure.

Abstract: The present invention relates to an arrangement for controlling a hydraulically driven motor, forming part of a hydraulic system in which hydraulic fluid under pressure forms a main flow through a main duct in which the motor is connected. The motor drives a varying load, and one or more valves (7) are adapted for controlling the hydraulic fluid flow through the motor on the one hand during operation and on the other hand for starting and stopping of the motor. One of the valves consists of a flow control valve (7) which is connected in the main duct (1) downstream of the outlet of the motor, and the flow control valve (7) is integrated with the motor housing (50).

Abstract: The invention relates to a device for controlling the opening and closing of a compressed gas consuming circuit (U), the device comprising a normally-closed two-position cutoff valve (2), said cutoff valve (2) having a pilot chamber (2a) and a counter-pilot chamber (2b) permanently in communication with a source (P) of compressed gas, directly for the pilot chamber (2a) and via a constriction (6) for the counter-pilot chamber (2b), the counter-pilot chamber including a purge branch connection (8) that is opened or closed by a two-position, two-port valve (9).

Abstract: A suspension system includes four electronically controlled actuators, one at each of the four wheels. The actuators are each controlled by an electronic control unit. The left front and right front actuators are mechanically connected with each other. The left rear and the right rear actuators are also mechanically connected with each other. The only connection between the front two actuators and the rear two actuators is an electronic communication through the electronic control unit.

Abstract: A hydraulic circuit for an actuator that has a piston and piston rod that will move a load in a first direction, and which can be externally loaded in an opposite direction, includes a flow compensated valve between the actuator and a control valve. When the piston in the actuator is moved in the second opposite direction under the external load and the rate of flow of fluid out of the actuator through the flow compensated valve exceeds a selected rate, an orifice is introduced in the flow path to restrict flow from the actuator.

Abstract: A flow control valve includes a pressure compensating valve and a first switching valve. The pressure compensating valve is configured to enlarge an opening area of a variable orifice between a load pressure line and a compensating pressure line when a pressure of working fluid of the compensating pressure line is smaller than a first set pressure, and narrow the opening area of the variable orifice when the pressure of the working fluid of the compensating pressure line is larger than the first set pressure. The first switching valve is configured to switch between a meter-out operation and a neutral operation by an external operation, wherein the working fluid of the compensating pressure line is drained in the meter-out operation, the working fluid of the compensating pressure line is not drained in the neutral operation. The load pressure line guides the working fluid to be supplied to an actuator.

Abstract: The invention relates to a valve arrangement having an adjustable control valve (10), comprising a control slide (12) for actuating at least one consumer connection (A,B), and having an LS control line, wherein the differential pressure of two actuating pressures (Xa, Xb) serves for the actuation of the control slide (12). Due to the fact that the actuating pressures (Xa, Xb) also actuate a logic valve, which in turn influences an additional valve, and/or actuates a pressure scale that is connected upstream to the control valve (10) having the control slide (12), the difference of the two actuating pressures (Xa, Xb) initially displaces the control slide of the control valve, wherein the higher or the lower of the two actuating pressures (Xa, Xb) either actuate the further valve in the form of the additional valve, and/or influences the pressure scale.

Abstract: A hydraulic control apparatus for a single action cylinder includes a switch valve for supplying fluid to and draining fluid from the cylinder, a cylinder side passage connected to the cylinder, a switch valve side passage connected to the switch valve, and a valve body accommodation chamber. The valve body accommodation chamber linearly extends between the cylinder side passage and the switch valve side passage. An on-off valve is located in a vicinity of a first end of the valve body accommodation chamber. The on-off valve defines a first back pressure chamber. A flow control valve is located in a vicinity of a second end that is opposite to the first end. The flow control valve defines a second back pressure chamber. The on-off valve and the flow control valve are separated from each other by a partitioning member.

Abstract: The force feedback poppet valve includes a valve body having a main chamber, a first port, and a second port. The force feedback poppet valve further includes a main poppet disposed within the main chamber and movable between an open position and a closed position to control fluid flow between the first port and the second port. The main poppet forms a control chamber within the main chamber. The force feedback poppet valve further includes a first passage communicating the control chamber with the second port, a second passage communicating the control chamber with the first port, and a pilot valve having a pilot poppet for controlling fluid flow between the control chamber and the first port through the second passage. The force feedback poppet valve further includes a pressure compensator disposed within the main poppet, and fluidly connected to the second port via the first passage.

Abstract: A hydraulic system is disclosed having a source of pressurized fluid, at least a one hydraulic actuator, and a first valve. The first valve has a first valve element movable relative to a first valve bore between a plurality of positions from a first position in which pressurized fluid is substantially blocked from flowing toward the at least one hydraulic actuator to a second position in which pressurized fluid is allowed to flow toward the at least one hydraulic actuator. The first valve element is configured to be selectively moved from a third position located between the first and second positions to a fourth position located between the third and second positions at least partially based on a pressure signal of pressurized fluid downstream of the first valve.