An electric fluid pressure cylinder is provided with: a driving unit integrally provided with an electric motor, a pump configured to discharge working oil by being driven by the electric motor, and a tank; a hydraulic cylinder configured to be extended and contracted by the working oil supplied from the driving unit; and a first hose pipe and a second hose pipe configured to guide the working oil between the driving unit and the hydraulic cylinder. The driving unit is further provided with: a valve block configured to control the flow of working fluid between the fluid pressure cylinder and the pump; and a connecting plate attached to the valve block and formed with a connecting port to which the pipe member is connected, the connecting port being configured such that the working fluid supplied to and discharged from the fluid pressure cylinder passes through the connecting port.

An assembly method of a piston-cylinder group (10), where the piston-cylinder group (10) includes a cylinder (20) at an end of which a head (40) is fixable, provided with seal gaskets (43). The method includes the steps of: mounting the seal gaskets (43) in appropriate seatings in the head (40); coupling the head (40) with the cylinder (20); and a low-temperature welding of the coupling between the head (40) and the cylinder (20).

A stability and control augmentation system (SCAS) actuator is operable for actuating a flight control surface of an aircraft. The SCAS actuator includes an actuator housing having a first aperture, a second aperture and a hydraulic chamber therebetween. A piston extends through the actuator housing. Fluid inlets are in fluid communication with regions of the hydraulic chamber. A first end portion of the piston is arranged to slide through the first aperture without a seal between the first end portion and the first aperture. A second end portion of the piston is arranged to slide through the second aperture without a seal between the second end portion and the second aperture. An intermediate portion of the piston is arranged to slide in the hydraulic chamber without a seal between the intermediate portion and the hydraulic chamber.

The subject matter of this specification can be embodied in, among other things, a fluid actuator system including a fluid actuator having a housing having an inner wall defining an interior cavity, a piston having a piston head configured for reciprocal movement within the interior cavity, the piston head contacting the inner wall and dividing the interior cavity into a first fluid chamber and a second fluid chamber, a first valve configured to control fluid flow between the first fluid chamber and a bypass conduit, and a second valve configured to control fluid flow between the bypass conduit and the second fluid chamber.

A housing (100) for housing hydraulic components, wherein the hydraulic components are configured for operating a hitch mechanism of a tractor, is a single-body component that is configured to house a plurality of valve mechanism and a reciprocating piston therein. The housing (100) comprises cavities for locating valve mechanisms therein and a cylinder (110) for accommodating a reciprocating piston (210). The housing (100) together with a plurality of valve mechanisms (122, 124, 126, 128, 130, 132) disposed in corresponding cavities, forms a predetermined hydraulic circuit (1000). The hydraulic circuit (1000) has minimum number of leakage joints, minimizes number of components and therefore assembly and machining operations.

A fluid pressure cylinder includes a first cylinder portion and a second cylinder portion disposed in parallel, and a supply-and-discharge port. The first cylinder portion is partitioned by a first piston into a head-side first accumulation chamber and a rod-side second accumulation chamber. The second cylinder portion is partitioned by a second piston into a head-side release chamber and a rod-side drive chamber. Pressurized fluid is supplied to and discharged from the second accumulation chamber and the drive chamber through the supply-and-discharge port. An end of a first piston rod connected to the first piston and an end of a second piston rod connected to the second piston are connected to each other. The first piston includes a communication switching valve switching communication between the first accumulation chamber and the second accumulation chamber, between enabled and disabled.

A pneumatic cylinder includes a cylinder body, a piston assembly, a connecting rod, and at least one pressure-relief valve. The cylinder body is formed with a cylinder chamber, and has an exterior disposed with at least one inlet-outlet passage and at least one pressure-relief opening, wherein the inlet-outlet passage is connected to the cylinder chamber. The piston assembly is contained within the cylinder chamber. The connecting rod is connected to the piston assembly, and protrudes out from the cylinder body. The pressure-relief valve is disposed in the pressure-relief opening, and has two ends connected to an outside of the pneumatic cylinder and the cylinder chamber respectively. When a gas pressure within the cylinder chamber is greater than a threshold value, the pressure-relief valve works to allow the cylinder chamber connecting to the outside for pressure relief.

The present invention regards an elongated fluid actuator arrangement comprising a first and second cylinder housing (3, 5) extending in a longitudinal direction (X), respective housing (3, 5) encompasses a first respective a second piston body (7, 9). The respective piston body (7, 9) divides the respective cylinder housing (3, 5) in a first and second cylinder chamber (11, 13). The arrangement (1) is adapted for connection to a valve member means (15) of a fluid supply device (17). A piston rod member (19) extending through said respective first and second piston bodies (7, 9). The first piston device (7) comprises a piston rod engagement and disengagement means (29), which is adapted to engage or disengage the first piston device (7) to/from the piston rod member (19), wherein an engagement area (A2), defined by an engagement zone between the first piston body (7) and the piston rod member (19), is larger than a cross-sectional piston area (A1) of the first piston body (7).

When viewed in section, a cylinder hole in a fluid pressure cylinder has a polygonal shape including inner circumferential surfaces parallel to a plurality of surfaces constituting a body. A piston has a polygonal outer edge having a shape corresponding to the shape of the cylinder hole and partitions the cylinder hole into a head-side cylinder chamber and a rod-side cylinder chamber. The body is cut off so that a first side surface has a stepped shape, and a solenoid valve is disposed in a solenoid valve arrangement space formed by cutting off the body. The solenoid valve is disposed inside a virtual outer shape defined by most-protruding faces in the respective surfaces.

A multistage piston actuator exerts a driving pressure against a spring pressure into pressure chambers of piston bodies, fitted into a cylinder body, to operate the push rod. Each piston body is combined with a partition fitted into the cylinder body. Each piston body includes a pressure receiving plate portion, and an axial rod and a slidable cylindrical guide portion extending concentrically in opposite directions, the axial rod having an axial air passage connected to the pressure chambers. Each partition includes a base plate portion having a through-hole which receives the axial rod of an adjacent piston body, a large-diameter outermost cylindrical portion fitted into the cylinder body, and a slidable cylindrical guide portion slidably fit-engaged with the slidable cylindrical guide portion of the piston body. The axial rods of each piston body are brought into contact to operate the push rod.