A servo valve comprises a valve housing, a cavity formed in the valve housing and a member disposed in the cavity and axially-moveable therein. The servo valve further comprises a piezoelectric actuator configured to axially move the member, relative to the valve housing, between first and second axial positions.

A servo valve comprises a member disposed in a cavity and axially-moveable therein. The member includes first and second sections, a central section located between the first and second sections and first and second transition sections respectively between the first and second sections and the central section, forming respective first and second outer surfaces angled relative to the axis (X). At least one of the transition sections comprises a non-circular cross-section having a concave portion forming at least part of the respective first and second surfaces and being at least partially aligned with and facing the respective first or second nozzle opening such that rotating the member in said cavity varies the level of obstruction of the first or second nozzle openings by the first or second outer surfaces.

An example valve includes: a piston movable between a neutral position and an actuated position, wherein in the neutral position: a second port of the valve is fluidly coupled to a first port, and a third port is fluidly decoupled from the second port; a solenoid actuator sleeve movable between an unactuated state and an actuated state, wherein in the actuated state, the solenoid actuator sleeve allows pilot fluid to apply a fluid force on a piston in a distal direction; a first feedback spring; and a second feedback spring disposed in series with the first feedback spring, wherein the first feedback spring and the second feedback spring cooperate to apply a biasing force in a proximal direction on the piston against the fluid force, wherein the piston is configured to move to the actuated position based on a relationship between the fluid force and the biasing force.

A pulse valve assembly including a main valve and two pilot valves. The main valve includes a main valve body, main valve bore, and main valve spool. The main valve body includes an inlet port, an outlet port, and a pressure chamber at one end of the main valve bore. A first pilot valve selectively supplies pressurized fluid to the second pilot valve depending on the position of a poppet, which is controlled by a solenoid. A second pilot valve includes a spool that is driven by pressurized fluid from the first pilot valve. The second pilot valve selectively supplies pressurized fluid to the pressure chamber in the main valve causing the main valve spool to move towards the open or closed position. When the main valve spool is in the open position, pressurized fluid can flow through the main valve from the inlet port to the outlet port.

An example valve includes: a piston movable between a neutral position and an actuated position, wherein in the neutral position: a second port of the valve is fluidly coupled to a first port, and a third port is fluidly decoupled from the second port; a solenoid actuator sleeve movable between an unactuated state and an actuated state, wherein in the actuated state, the solenoid actuator sleeve allows pilot fluid to apply a fluid force on a piston in a distal direction; a first feedback spring; and a second feedback spring disposed in series with the first feedback spring, wherein the first feedback spring and the second feedback spring cooperate to apply a biasing force in a proximal direction on the piston against the fluid force, wherein the piston is configured to move to the actuated position based on a relationship between the fluid force and the biasing force.

An example valve includes: a piston movable between a neutral position and an actuated position, wherein in the neutral position: a second port of the valve is fluidly coupled to a first port, and a third port is fluidly decoupled from the second port; a solenoid actuator sleeve movable between an unactuated state and an actuated state, wherein in the actuated state, the solenoid actuator sleeve allows pilot fluid to apply a fluid force on a piston in a distal direction; a first feedback spring; and a second feedback spring disposed in series with the first feedback spring, wherein the first feedback spring and the second feedback spring cooperate to apply a biasing force in a proximal direction on the piston against the fluid force, wherein the piston is configured to move to the actuated position based on a balance between the fluid force and the biasing force.

A hydraulic servo valve comprising a pair of opposing receiving ports, a piston disposed between the pair of opposing receiving ports and an actuator in contact with the piston. The actuator is configured to provide axial movement of the piston in response to being actuated. The piston comprises a pair of opposed openings that are in operable fluid communication with a respective one of each of the receiving ports, and the axial movement of the piston is configured to vary the amount of a fluid pressure communicated between a respective one of the openings and receiving ports.

A servo valve comprises a valve housing, a cavity formed in the valve housing and defining a longitudinal axis (X), and a member disposed in the cavity and axially-moveable therein, wherein the member comprises a portion with first and second cylindrical sections having a first diameter (R1, R2), a central section located between the first and second cylindrical sections and having a second diameter (R3), and first and second frusto-conical sections connecting the first and second sections to the central section and forming respective first and second frusto-conical surfaces. A plurality of ports, each form a fluid passage through the valve housing and have first and second nozzles with first and second nozzle openings.

An electro hydraulic valve for a cam phaser, including an electromagnetic actuator assembly, and a hydraulic assembly, wherein the electromagnetic actuator assembly and the hydraulic assembly are arranged axially aligned along a longitudinal axis, wherein the hydraulic assembly includes a valve housing in which a valve piston is arranged axially movable along the longitudinal axis, wherein a plunger for positioning the valve piston along the longitudinal axis is arranged within the electromagnetic actuator assembly, and wherein the electromagnetic actuator assembly and the hydraulic assembly are connected with one another indirectly or directly, wherein the electromagnetic actuator assembly includes an actuator housing and a friction or form locking connection of the electromagnetic actuator assembly with the hydraulic assembly is provided by an ultrasonic weld between the actuator housing and the valve housing.

The present invention provides a valve including: an inlet unit IL; an outlet unit OL perpendicular to the inlet unit; and an opening/closing unit. The opening/closing unit includes: a rod to open or close the discharge port while extending or retracting in the discharge port in a flow direction of the fluid, having a poppet to open or close the discharge port, and having a piston to be pressed by a pilot gas; a body having a guide to accommodate the rod and guide the extension and retraction of the rod, and pressing spaces into which the pilot gas is introduced; and a solenoid valve to supply the pilot gas into the pressing spaces, in which the opening/closing unit has no spring, and in which a diameter of a seat, which comes into contact with the poppet in the outlet unit, is greater than a diameter of the guide.