A servovalve system comprising a pilot stage valve in communication with an hydraulic stage valve, the hydraulic stage valve comprising a valve member movably mounted in a valve chamber to selectively meter fluid flow in a flow path from an upstream inlet port to a downstream outlet port and at least two variable-sized orifices disposed in the flow path between the inlet and outlet ports, an upstream pressure sensor, a downstream pressure sensor, a fluid temperature sensor, a position sensor sensing a linear position of the valve member, a controller that receives input from the upstream pressure sensor, the downstream pressure sensor, the fluid temperature sensor and the position sensor; and the controller configured to provide a control signal to the pilot stage valve as a function of the input from the upstream pressure sensor, the downstream pressure sensor, the fluid temperature sensor and the position sensor.

A damping device, in particular for damping or preventing pressure impacts, like pulsations, in hydraulic supply circuits, comprising a damping housing (1) which surrounds a damping chamber and has at least one fluid inlet (13) and a fluid outlet (15) and a damping tube (21; 51) located in the flow path between the damping inlet and outlet, said damping tube having at least one branch opening (29; 73, 75, 77, 79, 81) passing through the tube wall and leading to a Helmholtz volume (27; 53, 55, 57, 59, 61) inside of the damping housing (1) for forming a Helmholtz resonator in a region positioned inside of the length of the damping tube, characterized in that a fluid filter (35) is arranged inside of the damping housing (1) in the flow path running between the fluid inlet (13) and fluid outlet (15).

A hydraulic system including a first cylinder conduit configured to couple to a cylinder, an auxiliary conduit configured to couple to a case drain conduit, and a pressure regulator coupled to the first cylinder conduit and to the auxiliary conduit. The pressure regulator may block fluid flow to the auxiliary conduit if a first fluid pressure is less than or equal to a threshold pressure and enable fluid flow if the first fluid pressure is greater than the threshold pressure. The hydraulic system further includes a supplemental conduit with a check valve that directs fluid from the auxiliary conduit to a reservoir. The check valve blocks fluid flow if a second fluid pressure is less than or equal to a third fluid pressure, and enables fluid flow if the second fluid pressure greater than the third fluid pressure.

A method is provided for detecting and quantifying leaks in a gas network under pressure or vacuum. The gas network may have a sensor(s) capable of recording the status of a source(s), consumers, consumer areas or applications. The method includes: a start-up phase; a training or estimation phase; and an operational phase. The operational phase includes: reading out the first group of sensors; calculating or determining the value of a second group of sensors from the readings from the first group of sensors; comparing the calculated or determined values of the second group of sensors with the read values of the second group of sensors and determining the difference between them; determining, on the basis of a residual value analysis, whether there is a leak in the gas network; generating an alarm and/or generating a leakage rate and/or generating the corresponding leakage cost if a leak is detected.

An object of the present invention is to prevent breakage of a unidirectional filter part for high-pressure oil. A hydraulic device 100 supplies oil to a high-pressure oil channel L1 and a low-pressure oil channel L2 from an oil tank 102 via a supply pump 104. The hydraulic device 100 includes an accumulator 106 capable of accumulating a hydraulic pressure of the oil supplied to the high-pressure oil channel from the supply pump; a filter part 120 disposed between the supply pump and a connection point N1 at which the high-pressure oil channel connects to the accumulator, along a direction in which the oil is supplied; and a check valve 110 capable of preventing a backflow of the oil to the filter part, and disposed between the filter part and the connection point.

A system for automatic calibration of an actuator, where the system has an actuator and a computer, and the computer further includes a PID controller. A sensor connected to the actuator transmits values representing the motion of the actuator to the input of the PID controller. The computer is programmed to compare the values representing the motion of the actuator to the output of the PID controller, thus outputting an error signal representing the difference between the output of the PID controller and the values representing the motion of the actuator. The computer stores this difference as a calibrated set point for the actuator when the difference is less than a predetermined amount. This calibrated set point is used to initialize the operation of a machine propelled by the actuator.

A working machine includes a prime mover, a hydraulic pump driven by power of the prime mover, a cooler including a cooling fan rotated by either the power of the prime mover or hydraulic fluid delivered from the hydraulic pump, and a controller configured or programmed to perform a reduction control for reducing a target fan rotation speed that is a target rotation speed of the cooling fan in response to reduction of an actual prime mover rotation speed that is an actual rotation speed of the prime mover, and to perform, after the reduction control, a restoration control for restoring the target fan rotation speed. The controller is configured or programmed to make a difference between a reduction rate of the target fan rotation speed in the reduction control and an increase rate of the target fan rotation speed in the restoration control.

A hydraulic system including a first cylinder conduit configured to couple to a cylinder, a second cylinder conduit configured to fluidly coupled to the cylinder, and a bypass conduit fluidly coupled both to the first cylinder conduit upstream of the cylinder and to the second cylinder conduit downstream of the cylinder. The bypass conduit is configured to enable intermittent fluid flow of a hydraulic fluid from the first cylinder conduit to the second cylinder conduit while bypassing at least a portion of the cylinder.

An apparatus, system, and method for reducing the warpage of a rotor of an aircraft engine. When the aircraft engine is placed in standby mode, a solenoid-operated bypass valve may receive a control signal to open. When open, the solenoid-operated bypass valve places an electric hydraulic pump in fluidic communication with an engine driven hydraulic pump. The engine driven hydraulic pump rotates because of the pressured provided by the electrical hydraulic pump. The mechanical linkage between the engine driven hydraulic pump and the rotor causes the rotor of the aircraft engine to rotate.

A nozzle of or for a servo valve comprises a nozzle element having a fluid outlet at a first axial end and a tubular body extending from the first end to an opposed, second axial end. The nozzle further comprises a plug element mounted in and closing the second axial end of the tubular body, thereby defining an internal cavity within the tubular body. One or more openings are formed through the tubular body to fluidly communicate with the internal cavity. A filter may be mounted across the internal cavity at a position axially intermediate the openings and the fluid outlet.