A pressure compensator, particularly for oleodynamic applications, comprising two cylinders: a compensator cylinder in which is slidingly engaged a first piston comprising a first piston rod, and a reducing cylinder, in which is slidingly engaged a second piston comprising a second piston rod axially connected to the first piston rod; said compensator cylinder being coupled to a main oleodynamic cylinder; said compensator cylinder having a size so designed as to provide the same area ratio as that of the main cylinder, thereby to a set position of said main cylinder piston corresponding a precise position of the first piston of the compensator cylinder; said reducing cylinder comprising at least a low-pressure chamber coupled to a pressure gauge; a displacement of the reducing cylinder piston rod either increases or decreases a pressure in said low-pressure chamber, proportionately to a working pressure in the main cylinder.

Provided is a double nozzle type positioner, which includes a flapper (1), a first nozzle (2) and a second nozzle (3) disposed at both sides based on the flapper (1), a first orifice (4) configured to maintain a constant pressure of the first nozzle (2), a second orifice (5) configured to maintain a constant pressure of the second nozzle (3), a first pilot valve (6) having an input portion connected to a feed pressure, a second pilot valve (7) having an input portion connected to an output portion of the first pilot valve (6), a discharge hole (8) connected to an output portion of the second pilot valve (7), and an actuator (9) connected to the output portion of the first pilot valve (6) and the input portion of the second pilot valve (7). If the first nozzle (2) is opened due to the movement of the flapper (1), the second nozzle (3) is closed, and if the first nozzle (2) is closed, the second nozzle (3) is opened.

A transducer for a connection to a fluid pressure source having a mechanism for setting a pneumatic output by way of an electrical input signal. The transducer provides a lower housing assembly and an upper housing assembly. The lower housing assembly comprises lower housing configured to receive a supply nozzle. The supply nozzle fluidly communicates with a supply port and intermittently fluidly communicates with an output port of the lower housing through an internal fluid passageway. The lower housing further comprises an exhaust nozzle fluidly communicating with an exhaust port and intermittently fluidly communicates with the output port of the lower housing through the internal fluid passageway. The upper housing assembly comprises an upper housing configured to receive a coil and an armature such that the upper housing, coil and armature define a latching electromagnetic circuit that provides alternating contact of the armature with the supply nozzle and the exhaust nozzle of the lower housing assembly.

A propeller hydraulic actuation system, includes a double-acting dual chamber hydraulic pitch change actuator. The pitch change actuator includes a first pressure circuit having first fluid supply lines and a first hydraulic chamber and a second pressure circuit having second fluid supply lines and a second hydraulic chamber. A piston separates the first and second chambers. At least one pressure sensor is provided for obtaining pressure measurements from which a load differential (F) applied to the piston by the circuits can be calculated. A closed loop controller is arranged to control the fluid supplied to the first and second pressure circuits, wherein the closed loop controller includes an actuator position loop arranged to utilise feedback on the actuator position to control the actuator position.

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.

In one embodiment, systems and methods include using a pressure relief shipping adapter to reduce the internal pressure of a container. A pressure relief shipping adapter comprises a body comprising a first portion and a second portion. The first portion comprises a first bore and a set of protrusions. The second portion comprises a second bore, wherein the second bore comprises a radial gap, wherein the radial gap comprises a uniform arc length along the length of the radial gap. A first end and a second end of the radial gap comprise a greater arc length than the radial gap. A pressure relief shipping adapter further comprises a pressure relief valve disposed at a first end of the first bore and an interlocking component comprising a first tab and a second tab, wherein the interlocking component is at least partially contained within the second bore.

A piezoelectric actuator for a miniature fluid transportation device is provided and includes a piezoelectric actuating plate and a piezoelectric element. The piezoelectric actuating plate includes a suspension plate, an outer frame, and brackets. The suspension plate has a first thickness. The outer frame is arranged around the suspension plate and has a third thickness. Each of the brackets is connected between the suspension plate and the outer frame and has a fourth thickness. The third thickness is larger than the first thickness, and the first thickness is larger than the fourth thickness. The suspension plate, the outer frame and the brackets are constructed to form different stepped structures to minimize the thickness of the brackets, enhance the elasticity of the brackets. Thus, displacement of the suspension plate in the vertical direction is enhanced and the transportation efficiency of the miniature fluid transportation device is intensified.

The present invention controls the pressure and flow rate of fluid, in order to obtain uniform performance, configure a closed loop magnetic circuit so as to include an electromagnet, a flapper, and a yoke material, and elastically deform the flapper itself by Maxwell attractive force generated between a magnetic pole of the electromagnet and the flapper to make the separation distance between the nozzle and the flapper variable. As opposed to a rigid flapper structure that swingably moves around a supporting point, like a conventional servo valve, the electromagnet, the magnetic pole, the nozzle, the flapper, and the like are arranged such that a change in magnetic gap directly leads to a change in air gap.

High strain hydraulically amplified self-healing electrostatic transducers having increased maximum theoretical and practical strains are disclosed. In particular, the actuators include electrode configurations having a zipping front created by the attraction of the electrodes that is configured orthogonally to a strain axis along which the actuators. This configuration produces increased strains. In turn, various form factors for the actuator configuration are presented including an artificial circular muscle and a strain amplifying pulley system. Other actuator configurations are contemplated that include independent and opposed electrode pairs to create cyclic activation, hybrid electrode configurations, and use of strain limiting layers for controlled deflection of the actuator.

A single stage flapper type servovalve comprises a valve housing comprising a bore, a pair of opposed nozzles arranged in the bore and a flapper element arranged between the pair of nozzles. The valve housing further comprises a plurality of fluid ports for communicating a working fluid to and from the nozzles and in fluid communication with the housing bore. The valve housing and the nozzles are both made from a stainless steel material.