A steam turbine valve drive apparatus in an embodiment includes a piston, a cylinder, a bidirectional pump, a servo motor, and a quick closing mechanism. The cylinder houses the piston in an inner space thereof, the inner space being partitioned by the piston into a first hydraulic chamber and a second hydraulic chamber. The quick closing mechanism executes a quick closing operation of closing the steam valve unit more quickly than the closing operation. Here, the quick closing mechanism executes the quick closing operation by feeding the working oil accumulated in an accumulator to the second hydraulic chamber and draining the working oil from the first hydraulic chamber.

An apparatus for controlling a hydraulic machine, for example a turbine, pump or pump turbine, using variable-speed driven fixed displacement pumps. The apparatus includes a device for carrying out an emergency shut-off that is characterized by low energy consumption and high efficiency while guaranteeing all the operation-relevant and safety-relevant requirements of a hydraulic machine.

The invention relates to a towing vehicle (100) for manoeuvring aeroplanes without using tow bars, the towing vehicle (100) comprising a coupling device (122/124) for gripping and lifting the nose wheel of the aeroplane to be manoeuvred. According to the invention, the towing vehicle (100) comprises a pressure store (176), in which operating fluid is stored under pressure, a release initiation device (178), which can be actuated manually by an operator and which in a release initiation position connects the pressure store (176) to a release device (180), and the release device (180), which is configured and intended, upon manual transfer of the release initiation means (178) into the release initiation position by the operator, initially to lower the nose wheel of the aeroplane automatically until it stands on the travel surface, simply by means of the pressure energy stored in the pressure store (176) and the potential energy of the nose wheel load, and only subsequently to release the nose wheel.

This disclosure includes systems and methods for actuating hydraulically-actuated devices.

A bootstrap hydraulic reservoir includes a bootstrap chamber to hold hydraulic fluid, a piston chamber fluidly connected to a pressure line of the hydraulic fluid system, a piston having a bootstrap end portion held within the bootstrap chamber and a pressure end portion held within the piston chamber, and a hydraulic accumulator fluidly connected to the pressure line of the hydraulic fluid system. The hydraulic accumulator accumulates pressurized hydraulic fluid from the pressure line. The bootstrap hydraulic reservoir also includes a valve fluidly connected to the pressure line of the hydraulic fluid system between the hydraulic accumulator and an outlet of a pump of the hydraulic fluid system. The valve includes an actuator selectively moves the valve to an open position when the pressure line of the hydraulic fluid system is de-pressurized.

An electric motor-driven, rolling element screw linear actuator is presented which work in cooperation with an hydraulic actuator and share several components. This is achieved through the integration of a screw-driven integrated nut piston assembly. Combining the use of an electric screw driven actuator can also reduce the need for a redundant hydraulic system, resulting in the elimination of 50% of connections, valves, piping, pumps, filters etc., while still being 100% redundant. An additional advantage is that the two drive systems are technologically independent, and therefore will not both fail because of an identical component flaw or failure point. The systems may also be used at the same time if conditions require force in excess of that generated by the hydraulic actuator alone.

An apparatus for controlling a hydraulic machine, for example a turbine, pump or pump turbine, using variable-speed driven fixed displacement pumps. The apparatus includes a device for carrying out an emergency shut-off that is characterized by low energy consumption and high efficiency while guaranteeing all the operation-relevant and safety-relevant requirements of a hydraulic machine.

The present invention discloses a power transmission control method and device for a crane and the crane. The method includes: setting the maximum working displacement of a secondary element corresponding to each gear of the crane; determining the current gear state and specific gear of the crane; determining the working mode of the secondary element from the gear state, and setting the maximum allowable displacement of the secondary element as the maximum working displacement corresponding to the specific gear.

An apparatus for controlling a hydraulic machine, for example a turbine, pump or pump turbine, using variable-speed driven fixed displacement pumps. The apparatus includes a device for carrying out an emergency shut-off that is characterized by low energy consumption and high efficiency while guaranteeing all the operation-relevant and safety-relevant requirements of a hydraulic machine.

The hydraulic system can include a control member that is operatively coupled to a member. The control member can include a hydraulic control member and an integrated inerter. Hydraulic fluid at variable pressures is moved through the hydraulic system by pumps. The hydraulic system can be configured for hydraulic fluid returning from the control member to the first pump to be delivered to the second pump prior to reaching the first pump. A dual-spool valve is positioned between the pumps and the control member to control the flow of the hydraulic fluid. The dual-spool valve is movable to move the hydraulic fluid at variable pressures into and out of first and second chambers of the control member. The dual spool valve can also be configured to operate the control member when a spool is not operational.