A bearing, a gas turbine unit having such a bearing, and a method for operating and for increasing the efficiency a gas turbine unit, wherein the bearing has an annular bearing body, on the axially opposing end faces of which are provided two thrust bearings, each having a plurality of bearing elements which are distributed over the circumference, project and are movable in the axial direction, and have a bearing surface. The bearing elements of each thrust bearing are hydraulically displaceable axially outwards in two stages by predetermined amounts of movement.

A hybrid electric propulsor equipped with a hydraulic coupling is provided. In one aspect, a propulsor includes a gas turbine engine and an electric machine operatively coupled thereto. The gas turbine engine includes a fan spool and a core spool. The electric machine is operatively coupled with the fan spool. A hydraulic coupling defines a sealed volume in which hydraulic transmission fluid is provided. The hydraulic coupling encases at least a portion of the fan spool and at least a portion of the core spool. The hydraulic coupling hydraulically couples the fan spool and the core spool and allows for power transmission between the fan spool and the core spool.

Embodiments of a fuel system are disclosed. The fuel system includes a bypass valve (BPV), a fuel metering valve (FMV), a flow sense valve (FSV), and an actuator regulating valve (ARV). The BPV includes a BPV valve member that regulates fuel flow from a BPV inlet to a BPV outlet. The position of the BPV valve member is controlled by pressures at an inlet and an outlet of the FMV. The FSV includes an FSV valve member that regulates fuel flow from an FSV inlet to an FSV outlet. The ARV includes an ARV inlet that is in fluid communication with the FSV outlet, and fuel flow through an ARV outlet regulates downstream actuators. The position of the FSV valve member to produce fuel flow through the FSV outlet to the ARV inlet is controlled at least in part by a pressure at the BPV outlet.

A gas turbine engine actuation system includes a gas turbine engine, an actuation device, an actuator, and a power source. The gas turbine engine includes a compressor section, a combustion section, a turbine section, and a rotating shaft. The actuation device is operable with the compressor section, combustion section, turbine section, or a combination thereof. The actuator is operationally coupled to the actuation device and includes an electric actuator configured to convert electrical current into mechanical power. The power source is configured to supply electrical current to the actuator, alone or in tandem with a hydraulic actuator.

A method for pressurizing exhaust gases from a turbine power plant includes the steps of: applying a pressure to at least a proportion, in particular a proportion rich in carbon dioxide, of the exhaust gases from the power plant by way of a fluid operating machine of a pressurization device, and applying a torque to the fluid operating machine and/or driving the fluid operating machine by way of such a torque, which is present at an output shaft of a main turbine of the power plant.

The subject matter of this specification can be embodied in, among other things, an actuator apparatus includes an output member configured to actuate between a first positional configuration and a second positional configuration, a source fluid reservoir, a fluid velocity resistor configured to provide a predetermined resistance to fluid flow, a fluid velocity fuse configured to flow fluid flows having a first predetermined range of fluid velocities and to block fluid flows having second predetermined range of fluid velocities, and a fluid actuator assembly configured to urge fluid flow from the source fluid reservoir through the fluid velocity resistor and the fluid velocity fuse based on actuation of the output member.

A gas turbine engine has a compressor section with a low pressure compressor and a high pressure compressor having a downstream end. A cooling air system includes a tap from a location upstream of the downstream most location. The tap passes air to a boost compressor, and the boost compressor passes the air back to a location to be cooled. The boost compressor is driven by a shaft in the engine through an epicyclic gear system. A speed control changes the relative speed between an input and an output to the epicyclic gear system.

A starter assembly for a gas turbine engine according to an example of the present disclosure includes, among other things, a fluid-actuated starter coupled to a spool, and a controller operable to cause a reduction in torque output of the starter in response to determining that a first predefined threshold is met. The first predefined threshold relates to an engine operational condition. A method for starting a gas turbine engine is also disclosed.

A braking system including a brake actuator, a control valve, a control assembly, and at least one pressure sensor. The control valve is disposed to direct hydraulic fluid to the brake actuator at a rate corresponding to a magnitude of a control signal. The control assembly includes a mixed-mode control system. The at least one pressure sensor is configured to measure a pressure of the hydraulic fluid to the brake actuator. The control assembly is configured to determine a position of the brake actuator. The mixed-mode control system is configured to determine a position command and a pressure command. The mixed-mode control system is configured to adjust the magnitude of the control signal based on at least one of the position command and the pressure command so as to reposition the brake actuator from a first position to a second position.

A thrust reverser actuation system for a jet propulsion engine for a vehicle, the thrust reverser actuation system comprising: a plurality of hydraulically-driven thrust reverser actuators for actuating one or more thrust reverser components of the jet propulsion engine, each actuator comprising: a hydraulic circuit; and a bi-directional electrically-driven pump configured to pump hydraulic fluid through the hydraulic circuit, wherein the hydraulic circuit and the pump are configured such that the direction of the pump dictates the direction of the actuation of the actuator.