According to one embodiment, an actuator includes a plurality of channel members each having at least one first port into which fluid flows and at least one second port from which the fluid flows out. At least one of the channel members includes a different number of second ports from a number of first ports. The channel members are joined with each other to form at least one channel component.

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 hydraulic forging press machine and a control method, whereby surging of the forging load or dead zones where the forging speed goes to zero is suppressed, and forging is performed with high precision throughout a wider range than the prior art, from low to high load. Pressure cylinders have a main pressure cylinder configured so working fluid is supplied during forging, and secondary pressure cylinders are configured so supplying and stopping of the supply of working fluid thereto are switched in response to the forging load, head-side hydraulic chambers of the secondary pressure cylinders being connected to a head-side hydraulic chamber of the main pressure cylinder via electromagnetic switching valves. Only the main pressure cylinder is used until the forging load exceeds a set load, and the number of secondary pressure cylinders used is sequentially increased as the forging load increases after the forging load exceeds the set load.

A variable compression ratio internal combustion engine comprises a crankshaft and a connecting rod. The connecting rod comprises a connecting rod body, a first hydraulic cylinder, a first hydraulic piston, a second hydraulic cylinder, a second hydraulic piston, a linking member, a hydraulic oil path, and a spool moving between a first position permitting supply of hydraulic oil from the second hydraulic cylinder to the first hydraulic cylinder, and a second position permitting supply of hydraulic oil from the first hydraulic cylinder to the second hydraulic cylinder. The variable compression ratio internal combustion engine further comprises biasing members arranged at a crank arm or a counterweight of the crankshaft and biasing the spool so as to selectively switch the position of the spool between the first position and the second position.

A modular actuator assembly which can be used for partial stroke testing of a valve, the assembly having a force module and a tandem piston module. The force module has a primary piston and piston rod interconnected to a shaft which is movably mounted therein. The tandem piston module is connected to the force module and has a tandem piston and piston rod. An indicator plate is connected to the piston rod and is selectively positionable on the tandem piston rod. The tandem piston rod extends into the force module and acts as a pneumatically engaged hard stop for preventing spurious travel of the primary piston and hence spurious valve travel.

Provided is an electro-hydraulic control system (10) for controlling the movement of a third structure (18) of an engine using a power actuator (26) mountable to the third structure (18), a telescoping fluid porting tube (24) for porting a fluid to the power actuator (26) and a control valve (22) for controlling the flow of movement to effect the movement of the third structure (18). In this way, the third structure (18), such as a nozzle slat of an engine, may be moved via a compact and lightweight electro-hydraulic system.

A fluid system includes a fluid control assembly in fluid communication with a fluid source in fluid communication with a fluid supply port and the fluid control assembly is in fluid communication with an actuator via an outlet port. A controller controls at least one supply valve and at least one exhaust valve. The at least one supply valve and exhaust valve are in a normally closed position until being actuated by the controller to an open position. The fluid control assembly includes a pressure sensor in communication with the outlet port. Whereby when pressure in the outlet port is less than a predetermined pressure, a controller opens the supply valve to communicate fluid to the actuator via the actuator line and when the pressure in the outlet port is greater than a predetermined pressure the controller opens the exhaust valve to vent the is outside a predetermined range.

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 drive, preferably for a hydraulic press, having a first synchronized cylinder that comprises a piston between first and second pressure chambers; at least one hydraulic pump whereby the pump outlet is hydraulically connected with the first pressure chamber of the first synchronized cylinder and the pump inlet is hydraulically connected with the second pressure chamber of the first synchronized cylinder; at least a second synchronized cylinder that comprises a piston between first and a second pressure chambers; whereby the piston of the first synchronized cylinder is mechanically movably coupled with the piston of the second synchronized cylinder; whereby the first pressure chamber of the second synchronized cylinder is hydraulically connected with the pump outlet; and whereby the second pressure chamber of the second synchronized cylinder can be connected with the pump inlet when a pressure limit in the second pressure chamber of the second synchronized cylinder is exceeded.

Motion of rams in fluid cylinders to drive machine parts is equalized by equalization chambers between drive chambers for equalizing outward and inward driven motion of the rams and the attached machine parts, irrespective of portions of loads and forces on the machine parts in relation to the rams. Duplicated machine parts may be closely positioned or widely separated, while providing the same controlled equalized movement irrespective of loading. The movable elements may be tilted to new angular positions before they are translated by the rams.