A valve actuator control system, and a related manifold. The control system includes a pneumatic directional valve operable to move the actuator. The manifold has multiple internal channels and is mountable to the pneumatic directional valve in alternative connections so that one internal channel of the manifold is active and the others are non-active, so that the manifold and pneumatic directional valve can provide operability of the actuator in a plurality of different fail modes.

A system and method configured to direct the braking energy from a high-pressure port at the motor side of a hydraulic circuit to emergency steering, braking, accumulator(s) charging, and/or various work functions. The system and method are also configured to return hydraulic fluid back to the same high-pressure port when the motor is running as a pump.

A steering system for a trailing or leading axle of a vehicle includes a steering angle sensor for measuring a steering angle of wheels of a front axle of the vehicle, a driving speed sensor for measuring a driving speed of the vehicle, an electric motor that drives a hydraulic pump, and a working cylinder connected to the hydraulic pump for steering the wheels of the trailing axle. The system also includes a control device that determines a trailing angle of wheels on the trailing axle of the vehicle and actuates the electric motor in a corresponding manner. The working cylinder has a center position borehole via which hydraulic fluid is released from the working cylinder. A piston closes the center position borehole in the straight-ahead position of the wheels of the trailing axle. The center position borehole can only be closed by a piston seal of the piston.

Techniques involve a hydraulic valve module having at least one hydraulic valve with a valve slide which can be adjusted by way of an electric actuator in order to supply hydraulic lines with hydraulic liquid by way of the hydraulic valve. The hydraulic valve module has a controller and an electric energy store. The controller and the electric energy store are set up to move the valve slide out of every possible valve slide position into a deactivation position by way of the electric actuator and energy which is stored in the electric energy store. This allows the safe operation of hydraulic valves without a restoring spring, wherein valves of this type and the actuators thereof can be of smaller and less expensive construction than in the case of conventional valves with a restoring spring.

A hydraulic adjusting device, in particular for use in a power plant and/or a wind power plant, includes a double-acting adjusting cylinder that has an adjusting function for a working operation and for a special operation. The double-acting adjusting cylinder is configured to be pressurized with a working pressure medium. In order to satisfy the adjusting function in the special operation, the double-acting adjusting cylinder is further configured to be connected to a pressure medium reservoir that has a pressurized gas isolated from the working pressure medium. The adjusting cylinder has a working chamber configured for the adjusting function of the special operation, the piston area of which is coupled to a piston arrangement of the adjusting cylinder that is configured for the working operation or is configured to be coupled to the piston arrangement.

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.

The present invention provides a work machine including a steering device that is very responsive to switching operations. The work machine includes: a proportional solenoid valve for outputting a first pilot pressure oil with a pressure responding to a steering signal; a solenoid valve for outputting a second pilot pressure oil with a predetermined pressure while the steering signal is outputted from the steering device; a switching valve capable of switching to a first state of outputting the first pilot pressure oil to a directional control valve and a second state of outputting the second pilot pressure oil to the directional control valve, while the first pilot pressure oil is outputted from the proportional solenoid valve and the second pilot pressure oil is outputted from the solenoid valve in parallel; and a controller to switch the switching valve from the first state to the second state in a case where a malfunction is detected in a main circuit ranging from the steering device to the directional control valve via the proportional solenoid valve and the switching valve of the first state.

An actuator assembly includes an actuation member, a release member, and a source of pressurized gas, wherein during a normal mode of operation, the actuation member and the release member are engaged to move in unison, and wherein during an emergency mode of operation, pressurized gas automatically decouples the actuation member from the release member to move separately. In accordance with yet other aspects of the present disclosure, an electro-mechanical actuator includes an electro-mechanical drive system and an integrated backup system operated by a gas generator, wherein when the backup system is activated, the electro-mechanical drive system is decoupled and the actuator moves to a predetermined position and mechanically locks in place.

The invention relates to a hydraulic cylinder, for example for use in a hydraulic tool, comprising at least one piston/cylinder combination composed of a cylinder body and a piston accommodated in said cylinder body and provided with a piston rod that projects from said cylinder body, wherein the cylinder body and the piston body define a first cylinder chamber while the cylinder body, the piston body and the piston rod define a second cylinder chamber, and wherein during operation the piston performs alternating forward and return operational cycles under the influence of a fluidum under pressure that is conducted to the first and the second cylinder chamber through a first and a second line, respectively, and a control valve which regulates the supply of a fluid under pressure through the first or the second line to the piston/cylinder combination.

A hydraulic drive system raises and lowers an object by supplying and discharging operating oil to and from two ports of an actuator and includes a control device, first to fifth electromagnetic proportional control valves, first and second hydraulic pumps, a first and second control valve, and a lock valve. When a fourth pilot pressure is output, the second control valve causes the operating oil to be discharged from a first port in order to lower the object. The lock valve prevents the operating oil from being discharged from the first port by closing a path between the first port and the second control valve, and when a fifth pilot pressure is output from the fifth electromagnetic proportional control valve per an operating device, discharges the operating oil from the first port by opening the path between the first port and the second control valve, to lower the object.