The present disclosure relates to a valve assembly including a valve moveable between an open position where hydraulic fluid flow is permitted between first and second ports of the valve and a closed position where hydraulic fluid flow is blocked between the first and second ports. A characteristic vibration is generated by turbulent hydraulic fluid flow within the valve when hydraulic fluid flow is first initiated between the first and second ports as the valve moves from the closed position toward the open position. The valve assembly also includes a controller for providing electrical current to control movement of the valve via a solenoid. The controller includes an accelerometer for sensing the characteristic vibration. The controller identifies an electrical current value of the electrical current at a time when the characteristic vibration is detected.

A piezoelectric ring bender servo valve assembly reduces mechanical wear by removing mechanical components used in prior art servo valves. The assembly does not use torque motor, flapper, and feedback spring. In this manner, no moving parts are required, which reduces maintenance and costs. A pair of piezoelectric ring benders mount adjacently to a pair of nozzles. The piezoelectric ring benders independently regulate the flow of fluid through the nozzles by moving between an open position to enable flowage, and a closed position to restrict flowage. A linear position sensing device measures and provides feedback about the spool position to a valve controller. The valve controller allows the spool valve to move until valve position achieves command position and the force on the spool valve is in equilibrium with pressure difference across spool valve. An H-bridge operable to switch the polarity of a differential pressure applied across to a load.

Hydraulic control comprising at least one hydraulic valve, each hydraulic valve comprising a hydraulic distributor and an electric actuator. The hydraulic distributor comprises a valve slide mounted with the ability to slide in a body comprising hydraulic ports. The electric actuator is fixed to the body of the hydraulic distributor and comprises an electric motor, an electronic circuit comprising a circuit board, a linear-displacement output member coupled to the control slide, reduction gearing comprising gear wheels coupling the motor to the output member, and a housing in which the electric motor, the electronic circuit and the reduction gearing are mounted.

A pressure-limiting unit for a pressure booster for driving hydraulic tools. The unit includes a pneumatic unit that is driven by gas or air pressure, a hydraulic unit connected to the pneumatic unit and having a hydraulic port for connecting the hydraulic tool to the hydraulic unit in a fluid-tight manner and a pressure-limiting valve for adjusting the hydraulic pressure. The unit includes a closing element pushed against a valve seat by a spring element and having a displaceable adjusting element for adjusting the spring force of the spring element. To provide a pressure-limiting unit and a pressure booster for driving hydraulic tools with a pressure-limiting unit, which offer the possibility of making a precise adjustment of the hydraulic pressure in a simple way, the pressure-limiting unit includes a position detection unit connected to the adjusting element to detect the axial position of the adjusting element, an evaluation unit for determining the set hydraulic pressure as a function of the axial position, and an output unit for displaying the set hydraulic pressure.

A system, including: a fluidic actuator which can be acted upon by a pressurized fluid and has an actuator member, a pressurized fluid provision device which is adapted to carry out a position control of the actuator member and, within the position control, to act upon the fluidic actuator with the pressurized fluid in order to move the actuator member into a prescribed position, and a hose arrangement, including at least one hose via which the fluidic actuator is fluidically connected to the pressurized fluid provision device, wherein the pressurized fluid provision device is adapted to carry out the position control taking into account a system model describing the hose arrangement, the actuator and/or the pressurized fluid provision device.

A pilot device for a hydraulic directional valve includes a displacement sensor, a pilot valve, an actuating device, a coil assembly, and a circuit board. The displacement sensor has a sensor axis and the pilot valve has a valve axis. The valve axis and the sensor axis are arranged substantially parallel to one another so as to lie in a reference plane. The actuating device and the coil assembly are arranged adjacent to one another. The circuit board is arranged parallel to the reference plane. In each case, to establish an electrical contact, the coil assembly, the actuating device, and an electrical plug connection are either soldered directly to the circuit board or are in breakable electrical contact with a respectively associated, rigid contact assembly. The contact assembly is soldered directly to the circuit board.

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 spool valve device includes: a housing with channels; a spool moving to change channel connection statuses; an electric actuator including an electric motor and linear-motion conversion mechanism, the motor rotating an output shaft by torque corresponding to a drive current supplied to the motor, the mechanism converting rotational output shaft movement into straight movement and applying thrust corresponding to the torque to the spool to change position; a biasing member applying biasing force to the spool against the actuator thrust; an angle detector detecting an motor output shaft angular position; a driving portion driving the motor by controlling drive current flow supplied to the motor based on a position command input and the angular position detected by the angle detector; and an abnormality determining portion calculating the spool position based on the detected angular position and determine presence or absence of operation spool abnormality.

A pressure control device is provided and includes a body which has a groove-shaped flow path including a groove part and a widened part connected to the groove part and having a width larger than a width of the groove part, and a filter unit which captures foreign matters mixed in a fluid which passes through the groove-shaped flow path. The filter unit includes a frame body being in a cylindrical shape and including a through hole part which penetrates in a direction along a central axis, and at least one filter member being in a planar plate shape disposed to intercept the through hole part and supported inside the frame body, in which the filter unit is accommodated in the widened part so that a direction orthogonal to the central axis of the frame body is along a depth direction of the widened part.

A pressure control device includes a body having a groove-shaped flow path including a groove part and a widened part, and a filter unit capturing foreign matters mixed in a fluid which passes through the groove-shaped flow path; the filter unit having a frame body including a through hole part and a filter member in a planar plate shape disposed with respect to the through hole part, and the filter unit being accommodated in the widened part. The frame body has: a first part having a first shape, a second part having a second shape smaller than the first shape, and a step part located at a boundary part between the first part and the second part The second part has a storage part provided in a penetrating manner on a bottom part side of the groove-shaped flow path and storing the captured foreign matters.