A three-way valve assembly, including a valve body having a fluid flow path and a valve member movable in the fluid flow path between a supply port and a work port, and between a load sense passage and a pressure relief port. The valve member may move between a first position and a second position for controlling flow and regulating fluid pressure differences sensed in the flow path; and for limiting fluid pressure in the flow path to a predetermined pressure level set by a pilot-operated pressure limiter valve when the valve member is in the second position. The valve member may move between the second position and a third position to open the flow path from the load sense passage to the pressure relief port for relieving fluid pressure in the flow path when the fluid pressure from an over-loaded actuator exceeds the predetermined pressure level set by the pressure limiter valve.

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.

An axial differential pressure control valve (DPCV) having an annular body, a tubular body, a coaxial closing member for closing an outlet aperture for exit of the fluid from the tubular body, sealing separation means arranged between first and second chambers containing the return fluid and the delivery fluid, respectively, said separation means being movable axially upon activation of a thrust due to a pressure differential ΔP=P1−P2 and to the spring, wherein the closing member is fixed, and further comprising pins axially arranged between the ring nut and the abutment flange of the spring, wherein the pins pass through the pipefitting so as to come into contact with the said abutment flange and are designed to be displaced axially upon operation of the ring nut independently of the fixed closing member, so as to vary the compression of the spring.

A control device, for a hydraulic consumer (22) and susceptible to vibrations, includes a valve (24) having a control spool (40) controllable by an actuating device (46). The valve (24) has a pressure supply port (P), to which a pressure compensator valve can be connected, which can be supplied with pressure fluid from a pressure supply device. The actuating device (46) has a motor (74). A load-pressure-dependent force on the control spool (40) can be generated by a control device (66). That force at the control spool (40) acts on an electronic motor controller (208) of the DC motor (74), which detects a change of the force and acts as a damping of the vibrations of the consumer (22) against this change of force.

An example valve assembly includes a first workport fluidly coupled to a first actuator; a second workport fluidly coupled to the first actuator; a third workport fluidly coupled to a second actuator, wherein the third workport is fluidly coupled to the first workport via a first fluid passage; a fourth workport fluidly coupled to the second actuator, wherein the fourth workport is fluidly coupled to the second workport via a second fluid passage; and a spool axially movable in a bore within the valve assembly, wherein when the spool is shifted axially in a first axial direction, pressurized fluid is provided to the first workport and to the third workport via the first fluid passage, and when the spool is shifted axially in a second axial direction opposite the first axial direction, pressurized fluid is provided to the second workport and to the fourth workport via the second fluid passage.

Disclosed is a load-sensing multi-way valve work section comprising a valve body, which comprises a compensation valve and a reversing valve both formed therein, wherein the compensation valve is provided with a compensation valve bore formed in the valve body and a compensation valve spool accommodated in the compensation valve bore, with a compensation valve oil inlet chamber, a compensation valve oil outlet chamber, a spring-side control chamber and a springless-side control chamber all being formed inside the compensation valve bore; wherein the reversing valve is provided with a reversing valve bore formed in the valve body and a reversing valve spool accommodated in the reversing valve bore, the reversing valve spool being configured to control communications among a main oil inlet chamber, a first working oil chamber, a second working oil chamber, a first oil return chamber, a second oil return chamber, a first load-sensing feedback pressure sensing opening and a second load-sensing feedback pressure sensing opening formed in the reversing valve bore, the compensation valve oil outlet chamber being communicated to the main oil inlet chamber; and wherein the load-sensing multi-way valve work section also defines a feedback passage formed within the valve body, the feedback passage being configured to communicate one of the first and second load-sensing feedback pressure sensing openings with the spring-side control chamber depending on a position of the reversing valve spool in the reversing valve bore.

A control system for construction machinery includes a hydraulic cylinder operable by a working oil discharged from a hydraulic pump, a control valve arranged between the hydraulic pump and the hydraulic cylinder to control an operation of the hydraulic cylinder according to a position of a spool therein, the control valve having a first spool position for draining the working oil discharged from a chamber of the hydraulic cylinder to a drain tank, and a pressure compensated valve installed in a return hydraulic line through which the working oil discharged from the control valve at the first spool position is drained to the drain tank, the pressure compensated valve being configured to control a flow rate of the working oil passing through the pressure compensated valve according to a pressure difference between a front end and a rear end of the control valve.

A control device for controlling a hydraulic consumer (2), such as a working cylinder, has at least one control valve (18) having a control spool (20). Control spool (20) is guided in a valve housing (22) in a longitudinally movable manner and is actuated by an electric motor (24). Electric motor (24) can be controlled by control electronics (MC), which receive input signals from a sensor device (58, 60, 62) detecting at least one operating state of the consumer (2).

The present disclosure relates to a hydraulic valve arrangement comprising a first pilot operated proportional directional control valve having a first valve member that is displaceable in a first and a second axial direction for controlling direction of supply and discharge of hydraulic fluid to and from a hydraulic actuator, a first proportional electro-hydraulic control valve for controlling displacement of the first valve member in the first axial direction, a second proportional electro-hydraulic control valve for controlling displacement of the first valve member in the second axial direction, and a second pilot operated proportional control valve having a second valve member configured to be controlled by the first and second proportional electro-hydraulic control valves via a shuttle valve arrangement. Individual meter-in and meter-out control of the hydraulic actuator is providable by having the second pilot operated proportional control valve configured to operate as a meter-in valve of the hydraulic actuator and the first pilot operated proportional directional control valve configured to operate as a meter-out valve of the hydraulic actuator, or by having the first pilot operated proportional directional control valve configured to operate as a meter-in valve of the hydraulic actuator and the second pilot operated proportional control valve configured to operate as a meter-out valve of the hydraulic actuator. The present disclosure also relates to a vehicle comprising a hydraulic actuator and a hydraulic valve arrangement for controlling the motion of the hydraulic actuator.

A hydraulic connector for hydraulic circuits includes a female coupling and a male coupling which are configured to directly couple with and decouple from each other. The female and male couplings do not include inner spaces to accommodate a first sensor. A mutual connection of the female and male couplings facilitates flow of a fluid between the female and male couplings. At least either the male or female coupling includes a first hollow element which is applied directly to an external surface of the male or female coupling to define an inner space. Either the male or female coupling includes the first sensor positioned in the inner space formed by the first hollow element. The first sensor is configured to detect and transmit electronic signals corresponding to working and/or operating parameters and/or values of the connector to a receiver.