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 hydraulic mechanism is mounted on a forklift. The hydraulic mechanism has a control valve and a pressure compensation circuit for compensating pressure within the hydraulic mechanism. The pressure compensation circuit has a relief pressure valve and an unloading valve for releasing pressure within the pressure compensation circuit to a discharge oil passage. Upon instructed to perform cargo handling operation, the unloading valve is switched to an open state, and the relief pressure valve is thereby actuated, so that rapid increase of pressure within the circuit is avoided. Further, the unloading valve is switched to an open state, and the pressure within the hydraulic mechanism is thereby released to the discharge oil passage, so that the cargo handling operation by the tilt cylinder and the lift cylinder is restricted.

Disclosed is a multi-layer soft pneumatic actuator, including: a surface layer including driving protrusions formed on one surface; a first chamber layer stacked on the other surface of the surface layer and including a first chamber configured to partially overlap the driving protrusion; a second chamber layer stacked on a layer different from the first chamber layer on the other surface of the surface layer, including a second chamber having a partial region overlapping the driving protrusion and the first chamber; and an air line layer configured to inject air into each of the first chamber and the second 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 hydraulic system includes: a cylinder in which an interior of a tube is divided by a piston into a first pressure chamber and a second pressure chamber; a first bidirectional pump connected to the first pressure chamber by a first supply/discharge line; a second bidirectional pump connected to the second pressure chamber by a second supply/discharge line and coupled to the first bidirectional pump in a manner enabling torque to be transmitted between the first and second bidirectional pumps; a relay line connecting the first and second bidirectional pumps such that a hydraulic liquid discharged from one of the first and second bidirectional pumps is introduced into the other of the first and second bidirectional pumps; and an electric motor that drives the first or second bidirectional pump. At least one of the first and second bidirectional pumps is a variable displacement pump whose delivery capacity per rotation is freely variable.

Disclosed is an electric hydraulic actuator including a hydraulic cylinder and the hydraulic power generator. The hydraulic cylinder includes a hollow rod that is connected to a piston and is linearly movable to protrude outward or to retract. The hydraulic power generator includes a motor, a fluid tank, and a gear pump and a pilot check valve disposed in a pump housing. The cylinder housing and the pump housing are directly coupled to each other. The cylinder housing includes a first port through which the working fluid is transferred to a first side of the piston and a second port connected to a return pipe that is provided in the hollow rod. The pump housing includes a third port that is configured to communicate with the first port and a fourth port that is configured to communicate with the second port.

A fluid actuated linear drive includes a drive housing and a drive member which is movable between two stroke end positions. The drive member has a drive unit with a drive piston which divides off two drive chambers from one another, the drive chambers via two housing channels being connected to axial housing coupling openings which are arranged on a housing rear side. A multi-function module is built onto the housing rear side in a position of use and includes components of an external end position setting device for the drive member and is furthermore provided with module block channel systems which communicate with the housing channels and can be used for the feed and discharge of a drive fluid when the multifunction module is built onto the drive housing in the position of use.

The present disclosure relates to variable recruitment actuator systems and related methods. In one embodiment, a variable recruitment actuator system may include a high-pressure fluid connection and a plurality of actuators. A variable recruitment actuator mechanism may selectively recruit a subset of the plurality of actuators based on a position of the variable recruitment actuator mechanism by selectively placing the subset of the plurality of actuators in fluid communication with the high-pressure fluid connection. A control system to control the position of the variable recruitment actuator mechanism may operate based on an input from a user.

A hydraulic cylinder enclosing a cavity, the cylinder containing a thru hole, an inner cylinder surface, and a longitudinal axis, and a piston within the cavity and movable relative to the cylinder in parallel to the longitudinal axis between a first and second positions. The piston includes a rod extending through the thru hole, the piston attached to the rod and in sealed engagement with the inner cylinder surface, and dividing the cavity into low and high pressure cavities, and each of the low and high pressure cavities containing a hydraulic fluid. The hydraulic cylinder further including a flexible bladder within the high pressure cavity containing a gas and preventing the gas from mixing with hydraulic fluid in the high pressure cavity. The flexible bladder is attached to an end of the cylinder, and is expandable within the high pressure cavity so that when the piston is in the first position, the flexible bladder and the gas are compressed, and as the piston moves toward the second position, the flexible bladder and the gas fill at least a portion of the high pressure cavity.

The invention relates to a fuel-operated firing device for driving securing elements into a substrate, comprising at least one main combustion chamber for a fuel, a driving piston that can be driven out of the main combustion chamber in a firing direction by expandable gases, and a pre-chamber with which an ignition device is associated and in which a pressure acting on the main combustion chamber can build up prior to a fuel-air mixture being ignited in said main combustion chamber. In order to improve the efficacy and/or functionality during the driving in of securing elements using the fuel-operated firing device, the pre-chamber has at least two venting connections which are mutually spaced in an axial direction and which have passages that can be exposed conjointly in order to facilitate rapid venting of the pre-chamber.