In a fluid circuit for an air cylinder connected to a switching valve provided with exhaust ports, a head-side pressure chamber is connected to the switching valve by a first pipe, and a rod-side pressure chamber is connected to the switching valve by a second pipe. A first restrictor is disposed at a connection point between the first pipe and the switching valve or in the vicinity of a first output port of the switching valve, and a second restrictor is disposed at a connection point between the second pipe and the switching valve or in the vicinity of a second output port of the switching valve.

The various embodiments herein provide a coaxial hydraulic actuator assembly for an aircraft hydraulic system for providing the dual redundancy operations in normal and emergency operations. The embodiments herein adopt a coaxial hydraulic cylinder based actuator system comprising a conventional fixed cylinder with a moving piston actuator. The fixed cylinder with a moving piston actuator is located in a first region. The fixed cylinder with the moving piston actuator is manufactured in tandem with a moving cylinder with fixed piston actuator. The moving cylinder with a fixed piston actuator is located in a second region. The fixed piston actuator in the second region is also referred to as actuation rod. Further, the coaxial hydraulic cylinder based actuator system comprises a first adapter and a first cap for the first region. Similarly, a second adapter and a second cap are provided for the second region.

A hydraulic rotary feed-through with a neck which is accommodated in a housing via a bearing arrangement and through a pressurized fluid line extends to a pressure space with a seal arrangement provided axially between the pressure space and the bearing arrangement, the bearing arrangement and the seal arrangement are disposed in frames which are accommodated in the housing axially engaged with one another under pressure.

A device mounting structure for mounting a load maintaining mechanism on a hydraulic cylinder, a pipe for suppling and discharging working oil to and from the hydraulic cylinder being connected to the load maintaining mechanism such that the working oil is led thereto, includes a single coupling portion that includes a screw hole and is provided on the hydraulic cylinder, and a bracket to which the load maintaining mechanism is fixed, the bracket being coupled to the coupling portion via a first screw member that is screwed into the screw hole, wherein the bracket includes a first through hole through which the first screw member is passed so as to leave a gap in a radial direction.

A variable compression ratio apparatus may include: a connecting rod having an end connected with a crank pin of a crank shaft; a plunger housing formed at the other end of the connecting rod, the plunger housing having a space to which a plunger is inserted. In particular, the plunger moves upwardly and downwardly, and an outer circumference surface of the plunger contacts an inner circumference surface of the plunger housing. The apparatus further includes a protrusion protruded from the plunger to the plunger housing and connected with a piston, and a hydraulic pressure control valve for supplying hydraulic pressure to the space and moving the plunger by supplying hydraulic pressure.

A steering device includes: a cylinder demarcated into first and second chambers by a piston; a main valve having first and second shuttle chambers; a hydraulic source having first and second discharge ports; a first oil passage configured to connect the first chamber and the first shuttle chamber; a second oil passage configured to connect the second chamber and the second shuttle chamber; a third oil passage configured to connect the first shuttle chamber and the first discharge port; a fourth oil passage configured to connect the second shuttle chamber and the second discharge port; and a tank connected to the main valve via the third oil passage and the fourth oil passage. One of the first shuttle chamber and the second shuttle chamber of the main valve is in an opened state when the hydraulic source is stopped.

A gas cylinder includes supply passages for supplying, to an accommodation chamber, a part of gas supplied to a second port. When the pressure in a first pressure chamber is equal to or lower than a prescribed pressure, a valve element closes a discharge flow passage by the biasing force of a spring member and the pressure in the accommodation chamber. When the pressure in the first pressure chamber exceeds the prescribed pressure, the valve element is moved by the pressure in the first pressure chamber, against the biasing force and the pressure in the accommodation chamber, to thereby open the discharge flow passage.

A mechanical transmission system that transmits motions and forces from one location to another while allowing the relative position/orientation of the two locations to change continuously is disclosed. The system can be used to actuate the joints and tooling of a robotic arm using stationary motors in the robot's base. Since the motors do not contribute any weight or inertia to the arm, this yields a lightweight and agile arm that is more human safe. The transmission includes a controller hydraulic cylinder connected to a remote cylinder by a tubing assembly, which contains hydraulic fluid, and a wire cable. The fluid transmits pushing forces between pistons of the cylinders, while the cable transmits pulling forces. The tubing assembly allows the cylinders to move in space relative to one another.

The invention relates to a hydraulic cylinder, for example for use with a hydraulic tool, which hydraulic tool is provided with a frame and an element which is movable with respect to the frame by means of the hydraulic cylinder.

A hydraulic tool which is operated by means of a hydraulic cylinder as described above is known from, for example, European patent no. 0641618. This patent discloses a frame which is coupleable to a jib of an excavator or the like and to which an assembly of two jaws can be coupled. One of the jaws is pivotable with respect to the other jaw by means of a hydraulic adjusting cylinder (a double-acting piston/cylinder combination).

A locking unit for the parking lock of an automatic transmission, for locking the movement of a piston which is movable by a drive and which can be acted on with hydraulic pressure.