A control valve including: a valve housing including a piston space; and a control piston which is movably arranged in the piston space and sub-divides the piston space into at least a first valve space and a second valve space, the control valve including at least a leakage path which sets a desired leakage between the first valve space and the second valve space. A motor vehicle device including an adjustable rotary pump including an adjusting means, for adjusting a delivery volume of the rotary pump, and the control valve, using which a pressure for adjusting the adjusting means can be governed, the motor vehicle device including a means which presses the control piston into a first position and holds it there, and the at least one other inlet of the control valve is connected to a high-pressure side of the rotary pump when the rotary pump is in operation.

A device for controlling the flow of a fluid through a conduit from an upstream side of the device to a downstream side of the device. The device includes a valve aperture (30), a cylindrical mounting member (24) on the downstream side of the valve aperture, a valve member (26) on the outside of the cylindrical mounting member that moves reciprocally to open and close the valve aperture, a control volume (44) defined between the cylindrical mounting member and the valve member, an arrangement (8) for introducing a control pressure into the control volume, and a seal (34) between the outer surface of the cylindrical mounting member and the inner surface of the valve member that substantially seals the control volume. The valve member is acted on by the pressure of the upstream side (PI) and the control pressure (P4) so as to be moved by the difference between these pressures.

A method of decreasing tire pressure includes opening a wheel valve (22) to allow pressurized air from a tire (10) to be directed to a first valve assembly (14) and to atmosphere. A target pressure is selected for a fluid control conduit (28). The fluid conduit (28) is in fluid communication with the first valve assembly (14) and a second or control valve assembly (30). The pressure in the fluid conduit (28) is measured. If the measured pressure is greater than the target pressure, then the second valve assembly (30) is de-energized. If the measured pressure is less than the target pressure, then the second valve assembly (30) is energized. A valve (42) prone to leak under very low temperatures may be subjected to repeated cycles of pressure application and pressure release in order to form a fluid-tight seal.

A hydraulic system for a transmission of a motor vehicle, the system having first and second pumps for conveying hydraulic fluid into primary and/or system-pressure circuits so that an intended pressure prevails in the circuits. The system further including liquid retention means preventing a flow of hydraulic fluid conveyed by the second pump from being conducted through the first pump when the first pump is not conveying and the second pump is conveying, and preventing a flow of hydraulic fluid conveyed by the first pump from being conducted through the second pump when the second pump is not conveying and the first pump is conveying. The system additionally including a sailing-mode lubricating valve for controlling, by an open-loop system, a flow rate of hydraulic fluid conveyed by the second pump into the primary and/or secondary system-pressure circuits such that the intended pressure is set in the system-pressure circuits.

A fluid regulator includes an actuator assembly disposed in a valve body. A sleeve includes a cylindrical wall, a first plate, and a second plate. Each of the first plate and the second plate is disposed in a cavity of the sleeve. A stem extends through the sleeve and is axially aligned with a longitudinal axis of the body, and includes a passage extending partially through the stem. The actuator assembly includes first and second pistons. First, second, third, and fourth chambers are separately disposed between the sleeve, the first or second plate, or the first or second piston. The first and third chambers are in fluid communication, and the second and fourth chambers are in fluid communication via the passage of the stem. The actuator assembly actuates a control element in response to a fluid pressure receivable in the first, second, third, and/or fourth chambers.

A valve controls the discharge of fluid stored under pressure in cylinders (4) and includes a body (2) with a fluid inlet hole (3), a fluid outlet hole (5), and a sealing shaft (6) whose movement, determined by release means (7), opens or closes the fluid passage The release means (7) includes at least one pneumatic actuation hole (11) with non-return valve (12) and a hermetic chamber (10) associated with said sealing shaft (6), a pressure cartridge (8) of compressed gas associated with an electric and manual actuator (9) external to the body (2) and the hermetic chamber (10), which, transmits the motion to a rod (15) linked to said sealing shaft (6). A spring (16) tends to keep the sealing shaft (6) closed, when the pressure is zero or when the cylinder (4) is empty.

An inlet pressure valve regulation system to provide a regulated fluid flow includes a housing, first piston assembly, regulating valve, and inlet pressure conduit. The housing has an inlet at an inlet end which receives a pressurized fluid and an outlet at an outlet end which provides the regulated fluid flow. The piston assembly is arranged in the housing and has a first cavity and a control orifice to fluidly connect the inlet to the first cavity. The first piston assembly is configured to regulate the fluid flow. The regulating valve has a first valve chamber, a second valve chamber fluidly connected to a vent, a floating valve seat disposed between the first valve chamber and the second valve chamber, and a valve component. The floating valve seat includes a diaphragm and a seat having a passageway to fluidly connect the first valve chamber and the second valve chamber.

A valve subassembly includes a main spool having a continuously adjustable main orifice and a control spool having adjustable first and second orifices. The control spool has first and second end positions and is acted upon by a first spring toward the first end position. A fluid flow path starts from a pump and runs to an actuator via the first orifice, first control point, second orifice, second control point, main orifice, and third control point. Pressure at the first control point acts on the control spool toward the second end position and pressure at the third control point acts toward the first end position. The second orifice is closed between the first end position and an intermediate position, and opens from the intermediate position to the second end position. The second orifice opening decreases from the intermediate position to the second end position from a nonzero value to zero.

In accordance with at least one aspect of this disclosure, a system includes, a first moveable member disposed in a first chamber configured to move between a first position and a second position of the first moveable member to allow or prevent fluid from passing from an inlet of the first chamber to an outlet of the first chamber. A second moveable member is disposed in a second chamber configured to move between a first position and a second position of the second moveable member to allow or prevent fluid from entering a biasing chamber, the second chamber being fluidly connected to the first chamber.

In accordance with at least one aspect of this disclosure, a system includes, a first moveable member disposed in a first chamber configured to move between a first position and a second position of the first moveable member to allow or prevent fluid from passing from an inlet of the first chamber to an outlet of the first chamber. A second moveable member is disposed in a second chamber configured to move between a first position and a second position of the second moveable member to allow or prevent fluid from entering a biasing chamber, the second chamber being fluidly connected to the first chamber.