An automatic transmission includes a piston movable in an axial direction, a plurality of friction plates disposed on a side of a first surface of the piston, a fastening hydraulic chamber applying a hydraulic pressure to a second surface of the piston to move the piston to a fastening position where the friction plates are pressed to be fastened to each other, a release hydraulic chamber applying a hydraulic pressure to the first surface of the piston to move the piston to a release position where the friction plates are released, and a hydraulic pressure control valve that supplies and discharges the hydraulic pressure to and from each of the fastening hydraulic chamber and the release hydraulic chamber. An area of the second surface of the piston for receiving the hydraulic pressure is set to be larger than an area of the first surface for receiving the hydraulic pressure.

A valving system has an actuator member connected to move with an actuator piston and change the position of a valve member. There is a smaller face fluid chamber acting on a small area piston face, and a larger face fluid chamber acting on a larger face of the actuator piston. The torque motor has an armature and a flapper caused to move by current received at the armature. The flapper moves between two fluid ports to control the pressure in the larger face chamber. The flapper further has a positioning extension engaging a first feedback spring operable between it and a forward face of the actuator piston and providing a spring force in combination with a spring force from the positioning extension. A control is operable to provide current to the armature to control the fluid received in the larger face chamber. The controller is programmed to associate the current supplied to the armature to an actual position of the valve member. A method is also disclosed.

In a fluid pressure cylinder, first and second cylinder chambers facing respective opposite end surfaces of a piston are formed inside a cylinder tube including a supply port and a discharge port, and a first piston rod connected to one end surface side of the piston is formed to have a greater diameter than that of a second piston rod connected to another end surface side of the piston. Therefore, a second pressure-receiving area of a second pressure-receiving surface formed on the other end surface of the piston is greater than a first pressure-receiving area of a first pressure-receiving surface formed on the one end surface. Pressure fluid in the first cylinder chamber is supplied to the second cylinder chamber, whereby area difference between the first pressure-receiving area and the second pressure-receiving area causes the piston to move toward the first cylinder chamber.

In a fluid pressure cylinder, first and second cylinder chambers facing respective opposite end surfaces of a piston are formed inside a cylinder tube including a supply port and a discharge port, and a first piston rod connected to one end surface side of the piston is formed to have a greater diameter than that of a second piston rod connected to another end surface side of the piston. Therefore, a second pressure-receiving area of a second pressure-receiving surface formed on the other end surface of the piston is greater than a first pressure-receiving area of a first pressure-receiving surface formed on the one end surface. Pressure fluid in the first cylinder chamber is supplied to the second cylinder chamber, whereby area difference between the first pressure-receiving area and the second pressure-receiving area causes the piston to move toward the first cylinder chamber.

The travel end expansion valve (1) for a piston type pressure converter (2) whose master cylinder (3) and slave cylinder (4) define a master chamber (9) and a slave chamber (10), respectively, includes an expansion master cylinder (12) which communicates with the slave chamber (10) and in which there can move an expansion main master piston (14) which is mechanically connected by a lever type transmission (11) with progressive effect to an expansion slave pump piston (15) which can move in an expansion slave cylinder (13), the transmission (11) being provided in such a manner that, when the expansion main master piston (14) is at the top dead center, the expansion slave pump piston (15) is at the bottom dead center, and vice versa, while an expansion release actuator (30) can cause the transmission (11) to move.

The travel end expansion valve (1) for a piston type pressure converter (2) whose master cylinder (3) and slave cylinder (4) define a master chamber (9) and a slave chamber (10), respectively, includes an expansion master cylinder (12) which communicates with the slave chamber (10) and in which there can move an expansion main master piston (14) which is mechanically connected by a lever type transmission (11) with progressive effect to an expansion slave pump piston (15) which can move in an expansion slave cylinder (13), the transmission (11) being provided in such a manner that, when the expansion main master piston (14) is at the top dead center, the expansion slave pump piston (15) is at the bottom dead center, and vice versa, while an expansion release actuator (30) can cause the transmission (11) to move.

An actuator according to the present invention includes a cylinder, a piston inserted into the cylinder to be free to slide, a rod that is inserted into the cylinder and connected to the piston, a rod side chamber and a piston side chamber defined by the piston within the cylinder, a tank, a first opening/closing valve provided in a first passage that connects the rod side chamber to the piston side chamber, a second opening/closing valve provided in a second passage that connects the piston side chamber to the tank, a pump that supplies a working fluid to the rod side chamber, a motor that drives the pump, an exhaust passage that connects the rod side chamber to the tank, and a passive valve that is provided in the exhaust passage and has a predetermined pressure/flow rate characteristic.

Systems, methods and devices are described providing a selective hydraulic or electrically powered prime mover that is a (bi-directional power unit) PU system, including movement within a device or system used to compress and/or expand a fluid and provide fluid movement within the same device or system. The use of a (hydraulic power unit) HPU is involved and comprises at least a pump or other hydraulic fluid moving device often referred to as a prime mover, one or more first set of selective control valves delivering pressurized fluid to the device(s), and one or more second set of selective control valves returning unpressurized fluid from the device(s), a reservoir comprising a compensator tank, a port allowing for operation at ambient pressure, and a pressure measuring device measuring ambient pressure allowing for unbalanced flow to and from the mechanical (user) device as well as thermal expansion or compression.

Systems, methods and devices are described providing a selective hydraulic or electrically powered prime mover that is a (bi-directional power unit) PU system, including movement within a device or system used to compress and/or expand a fluid and provide fluid movement within the same device or system. The use of a (hydraulic power unit) HPU is involved and comprises at least a pump or other hydraulic fluid moving device often referred to as a prime mover, one or more first set of selective control valves delivering pressurized fluid to the device(s), and one or more second set of selective control valves returning unpressurized fluid from the device(s), a reservoir comprising a compensator tank, a port allowing for operation at ambient pressure, and a pressure measuring device measuring ambient pressure allowing for unbalanced flow to and from the mechanical (user) device as well as thermal expansion or compression.

An adsorption separation device is used with a cylinder, wherein the cylinder comprises a cylinder body, a first piston, and a second piston. The first piston and the second piston are arranged inside the cylinder body, and the first piston and the second piston are be spaced from each other. The cylinder further comprises a first shaft and a second shaft where the first shaft extends into the cylinder body and is connected with the first piston, and the second shaft is slidably sleeved in the first shaft and connected with the second piston. The adsorption separation device includes the cylinder. The cylinder and the adsorption separation device are actually two or more cylinders sharing the same cylinder body and controlling two or more pistons and shafts respectively. The control directions and strokes of the pistons are independent relative to each other and do not affect each other.