The invention relates to a valve, which is characterized in that between a neutral position (38) of a control spool (STS) and one of its end positions (34, 42) a regeneration position (36) is provided, in which two utility ports (A, B) are interconnected in a fluid-conveying manner, or a floating position (40) is provided, in which these utility ports (A, B) are interconnected in a fluid-conveying manner. The invention relates to a further valve, which is characterized in that by a further motion of the control spool (STS) in the same direction, as that, in which a fluid connection is established between the utility ports (A, B) starting from the neutral position (38), this fluid connection is interrupted.

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.

A valve includes a valve housing (33), which has at least one service connection (A, B), a pressure supply connection (P) and a return connection (T). In the valve housing (33), a control slide (STS) is guided so as to be movable longitudinally to control these individual connections. The supply pressure, which is applied to the pressure connection (P) to control a consumer (10, 12), connected to the service connection (A; B), is guided across at least one control side (56) of the control slide (STS) via an orifice plate (54) and a control channel (50). The control side (56) is positioned in a control chamber (58) in the valve housing (33) such that it can move. The control chamber (58) is connected to the return connection (T) via an additional orifice plate (59).

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.

A hydraulic actuator system includes a load sense assembly that is configured to transmit a load sense signal to a variable pump to vary a flow of pressurized fluid from the variable pump in response to the load sense signal to generate a desired flow to the actuator. The load sense assembly includes a load sense boost valve (LSBV) configured to dynamically boost the load-sense signal according to the desired margin pressure and the flow demand from the system. When flow demands are low, margin pressure will be above the set threshold of the adjustable LSBV, and no boosting occurs. When flow demands are high and pressure in the load sense line drops to the set threshold, or minimum margin pressure, the LSBV begins boosting the load sense signal pressure dynamically. The boosted load sense signal signals the variable pump to stroke and displace more fluid to increase flow to the actuator.

A Control Valve Compensation System for producing both a pre-compensated and a post-compensated load sensing hydraulic directional control valve module, wherein both configurations use the same components except for a sliding compensating component. The Control Valve Compensation System generally includes a hydraulic directional control valve housing which is adapted to be easily-interchangeable between a load sensing pre-compensated pressure configuration and a load sensing post-compensated pressure configuration by simply removing and replacing a different compensator assembly within the housing. The compensator assembly is adapted to direct oil flow through the housing while simultaneously providing compensation for the valve function. Directional valve assemblies may be provided, with the valve assemblies functioning to provide post-compensated functions, pre-compensated functions, and mixed pre- and post-compensated functions. These directional valve functions can be re-configured in the field by simply swapping the compensator assemblies to produce the desired functionality of the end-user at that particular time.

A hydraulic control arrangement for simultaneously supplying at least two hydraulic consumers with predefinable individual pressure medium flow rates includes a hydraulic pump having an adjustable swept volume, and at least two valve arrangements each including a variable metering restrictor and a pressure balance arranged downstream of the variable metering restrictor. Each pressure balance is configured to be acted on in an opening direction by pressure downstream of the respective variable metering restrictor and to be acted on in a closing direction by a highest load pressure or by a pressure derived therefrom. Each valve arrangement is arranged between a pump line, which leads away from the hydraulic pump, and a consumer of the at least two hydraulic consumers. The arrangement further includes an electronic control device, by which the hydraulic pump is actuatable such that it conveys a sum of the predefinable individual pressure medium flow rates.

A valve apparatus for influencing a flow of medium between a supply port (38) and a pressure port (40) has a valve device (10). In one closed position, the valve device blocks the connection between the supply port (38) and the pressure port (40). The valve device opens this connection in one opened position, in which the pressure port (40) is connected to at least one of two medium chambers (62, 80) by a respective fluid channel (64, 82). One fluid chamber (64) comprises a fluid duct (68) in the valve slider (22). The other fluid channel (82) has a further fluid duct (84) that is separate from the fluid duct (68). In one of the opened positions of the valve slider (22), the further fluid duct (84) opens at one end (92) into the medium chamber (80). In every displacement position of the valve slider (22), the further fluid duct (84) is permanently connected at the other end (94) to the pressure port (40).

A hydraulic system is provided. The hydraulic system includes a pump, a load sense conduit, a tank conduit, a function workport, and a function control valve. The hydraulic system further includes a function poppet valve arranged between the function workport and the function control valve and having a function poppet vent passage, and a system control valve arranged downstream of the function control valve. The system control valve is biased into a first position where fluid communication between the function poppet vent passage and the tank conduit is prevented and fluid communication between the load sense conduit and the tank conduit is provided. The system control valve is selectively movable to a second position where fluid communication between the function poppet vent passage and the tank conduit is allowed and fluid communication between the load sense conduit and the tank conduit is prevented.

The invention relates to a control device for a hydraulic consumer (22), susceptible to vibrations, comprising a valve (24) having a control spool (40), which can be controlled by means of an actuating device (46), wherein 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, wherein the actuating device (46) has a motor (74) and wherein a load-pressure-dependent force on the control spool (40) can be generated by means of a control device (66). In accordance with the invention, this 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.