A linear valve drive for connection to a valve body which has a valve seat is described, wherein said linear valve drive comprises a drive housing, a valve closure element and a piezoelectric actuator which is arranged within said drive housing. Said valve closure element is displaceable in the axial direction between an open position and a closed position by means of said piezoelectric actuator and an interposed actuating device. Said piezoelectric actuator is supported on said actuating device via its side directed towards the valve closure element. Said linear valve drive comprises an adjusting device which is configured such that an idle stroke of said linear valve drive is adjustable. A valve is also described.

In accordance with at least one aspect of this disclosure, a flow control device can include, a first plate having one or more windows defining a flow path therethrough, a second plate configured to abut the first plate, and an actuator operatively connected to one or more of the first plate and/or the second plate. The actuator can be configured to drive the first plate and/or the second plate relative to one another to enlarge or reduce the flow path through the one or more windows in the first plate.

In accordance with at least one aspect of this disclosure, a system can include, a moveable component configured to move between one or more positions, a biasing member operatively connected on a first side to bias the moveable component to a respective one of the one or more positions, and a preload member operatively connected to provide a force to a second side of the biasing member. An actuator can be operatively connected to move the preload member in response to a signal from a controller.

A servo valve comprising: a fluid transfer valve assembly comprising a supply port and a control port (P.sub.A, P.sub.B); a moveable valve spool arranged to regulate flow of fluid from the supply port to the control port in response to a control signal; and a drive means configured to axially move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow; wherein the drive means comprises a piezo actuator element mounted within and axially movable with the valve spool, the piezo actuator configured to extend axially in response to the control signal to cause corresponding axially movement of the spool.

The disclosed fluidic devices may include a valve chamber in a valve body, a fluid inlet into the valve chamber, a piston positioned within the valve chamber, a first fluid outlet for passing fluid out of the valve chamber when the piston is in a first position, a second fluid outlet for passing fluid out of the valve chamber when the piston is in a second position, a first piezoelectric actuator positioned and configured for moving the piston from the first position to the second position, and a second piezoelectric actuator positioned and configured for moving the piston from the second position to the first position. Various other methods, systems, and devices are also disclosed.

A servo valve comprises a first spool extending along a first spool axis, a second spool extending along a second spool axis, a first piezoelectric actuator, and a second piezoelectric actuator. The first piezoelectric actuator is operatively connected to the first spool for translating the first spool in response to a voltage applied thereto. The second piezoelectric actuator is operatively connected to the second spool for translating the second spool in response to a voltage applied thereto.

A piezoelectric valve includes: a valve main part including a gas pressure chamber receiving compressed gas supplied from outside; a plate inside the valve main part, and an actuator fixed to the plate and inside the valve main part, which is a case with an opening on a front surface. The plate includes a gas discharge path and a valve seat coming into contact with a valve element of the actuator opening and closing the gas discharge path. A lid member that closes the opening of the case has a gas discharge opening communicating with the gas discharge path of the plate; is welded and fixed to a front surface of the plate, where the gas discharge path opens, on an annular welded part surrounding the gas discharge opening; and is welded and fixed to an end surface of the case on an annular welded part on the outer peripheral part.

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.

An electrically actuated control valve has three mouths and three operating positions, in which the three mouths includes a first mouth for inlet of a working fluid, and a second mouth and a third mouth for outlet of the working fluid. The three operating positions include a first operating position in which a passage of fluid from the first mouth to the second mouth and the third mouth is enabled, a second operating position in which a passage of fluid from the first mouth to only one of said second and third mouths is enabled, and a third operating position in which the passage of fluid from the first to the second mouth and the third mouth is disabled. The control valve includes an electric or electromagnetic actuator for controlling the passage of fluid from the first mouth to the second and third mouths providing the aforesaid three operating positions.

A servo valve including a piezo-electric actuator, a flexible linkage, and control valves. The piezo-electric actuator is actuatable along a piezo stack axis. The flexible linkage is coupled to the piezo-electric actuator at opposite axial ends of the actuator. Control valves are disposed at laterally opposite sides of the piezo stack axis and include respective valve stems coupled to the flexible linkage. The flexible linkage may be configured to transfer motion of the piezo-electric actuator along the piezo stack axis to a motion of the valve stems along an amplification axis that is transverse to the piezo stack axis to open and close the control valves. A symmetric actuation element incorporating the piezo-electric actuator, or a different actuator, may have first and second chambers at laterally opposite sides thereof, and be electrically actuatable along an actuation axis to open and close supply and return ports to control fluid communication with respective first and second work ports of respective first and second chambers.