A control system is provided for a turbine valve. The turbine valve has a first coil and a second coil to control or sense movement of a mechanical valve positioner. Two valve positioners are provided with each valve positioner having two drive circuits to drive the first and second coils. Switches are provided such that only one drive circuit is connected to each coil at a time. The control system may also include a hydraulic pilot valve section and a main hydraulic valve section. Feedbacks are used to determine a pilot valve error and a main valve error which are combined to determine a turbine valve error. The turbine valve error is repeatedly determined to minimize the error.

A solenoid driven actuator system includes a first solenoid having at least one pressure input and a pressure outlet downstream from the at least one pressure input. A second solenoid has at least one pressure input and a pressure outlet downstream from the at least one pressure input. A transfer solenoid operatively coupled to the first and second solenoids. An actuator valve operatively coupled to a pressure outlet of the transfer solenoid.

A hydraulic lock apparatus includes a hydraulic actuator, a pressure storage device connected to the hydraulic actuator, and a control valve configured to actuate to a first position and a second position. The control valve fluidly isolates the pressure storage device from the hydraulic actuator when the control valve is in the first position. The control valve fluidly connects the pressure storage device to the hydraulic actuator when the control valve is in the second position.

Provided is an electrohydrostatic actuation system including an emergency shut-off circuit to be actuated stably with a simple configuration. The electrohydrostatic actuation system includes: a hydraulic cylinder (24) including a piston (25) to which a valve element is connected, a first chamber (24A), and a second chamber (24B); a hydraulic pump (21) configured to supply hydraulic fluid to the first chamber (24A) or the second chamber (24B); a servo motor (M) configured to drive the hydraulic pump (21); a shuttle valve (11) configured to establish communication to a downstream side under a state in which a hydraulic pressure generated by the hydraulic pump (21) is maintained; a solenoid valve (12) configured to receive the hydraulic pressure via the shuttle valve (11) as a pilot pressure; and a logic valve (13) including a first port configured to receive the pilot pressure from the solenoid valve (12), and a second port to be communicated to the first chamber (24A) of the hydraulic cylinder (24). When the solenoid valve (12) is brought to a de-energized state, the pilot pressure of the logic valve (13) is released, and the logic valve (13) causes the hydraulic fluid in the first chamber (24A) communicated to the second port to flow into the second chamber (24B) so that emergency shut-off of the valve element is achieved by a return spring (26).

The subject matter of this specification can be embodied in, among other things, a thrust reverser synchronization shaft lock system includes a rotatable shaft comprising at least one radial prong extending radially from the shaft, a hydraulic lock assembly that includes a housing, a piston head having a lock recess, a piston rod extending radially away from the shaft and configured to be urged by the piston head to move the first piston rod end out of engagement with the radial prong to selectably permit rotation of the shaft, and a bias member configured to urge the first piston rod end into engagement with the radial prong, and an electric lock assembly that includes a lock pin and an electric actuator configured to controllably extend and retract the lock pin in and out of engagement with the lock recess.

A turbine engine including: a rotor having at least one variable-pitch blade which is guided to rotate on bearings relative to a fixed structure; a system for controlling the pitch of the at least one blade, the control system being rigidly secured to the rotor and including a first actuator driven by energy, and the control system further being disposed axially upstream of the bearings; a device for transferring the energy, which is disposed axially between the bearings, the transfer device including a stationary element and a mobile element; wherein the rotor is annular and delimits an inner space which is open towards the upstream side and inside of which the control system is disposed.

There are described a system and method for operating a thrust reverser of an aircraft engine, the thrust reverser having a deployed state and a stowed state. The method comprises placing the thrust reverser in the stowed state when the thrust reverser is in the deployed state, a thrust lever associated with the engine is in a forward position, and the engine is rotating at a speed below an idle speed, wherein hydraulic pressure for stowing the thrust reverser is provided by a pump driven by the engine rotating at the speed below the idle speed.

A turbine pump system includes a turbine pump assembly including a housing, a pump located in the housing, a turbine located in the housing and operably connected to the pump, and a heat exchanger located between the pump and a hydraulic fluid load. The heat exchanger is configured to reduce a temperature of a hydraulic fluid flow output by the pump and directed to the hydraulic fluid load. The heat exchanger is operably connected to a turbine gas flow and utilizes the turbine gas flow to cool the hydraulic fluid flow at the heat exchanger.

A control arrangement for a coolant pump of an internal combustion engine includes a control slide which controls a throughflow cross-section of an annular gap arranged between an outlet of a coolant pump impeller and a surrounding delivery duct. A control pump adapts a hydraulic pressure generated in a flow duct. An electromagnetic valve includes a first and second valve seat, a first, second and third flow connection, a closing member and an armature. The first flow connection is fluidically connected to an outlet of the control pump. The second flow connection is fluidically connected to a first pressure chamber of the control slide. The third flow connection is fluidically connected to an inlet of the coolant pump. The first valve seat is arranged between the first flow connection and the second flow connection. The second valve seat is arranged between the second flow connection and the third flow connection.

A hydraulic and pneumatic control circuit for a turbojet, a main hydraulic line having an oil/fuel heat exchanger with a function of transferring heat from the oil flowing in an oil circuit of the turbojet to the fuel flowing in the main hydraulic line, the circuit having a first hydraulic line for feeding fuel to a combustion chamber of the turbojet, a second hydraulic line for feeding fuel to one or more actuators for controlling variable geometry equipment, each actuator being fed with fuel via an electrohydraulic servovalve, a pneumatic line for feeding air to a pneumatic control member for bleed valves of a compressor and a blade tip clearance control valve of a turbine of the turbojet, and a fuel/air heat exchanger positioned on the second hydraulic line upstream from the hydraulic servovalve and on the pneumatic line upstream from the pneumatic control member.