A transmission device drives a fuel pump for a turbomachine using a drive shaft of said turbomachine. The transmission includes a planet reduction gearing with three elements: a central planet gear, an outer ring gear and a planet carrier. A first of the three elements connects to the drive shaft and a second of the three elements couples to a shaft of the pump. The three elements can be rotated about a shaft of the reduction gearing. First electrical means rotatably drive the third element to modify a rotational speed ratio between the first and second elements. Second electrical means are coupled to the first or the second element. The first and second electrical means are arranged to transfer electrical power reversibly from one to the other.

Methods and fluid supply systems are provided for supplying fluids while adjusting a pump discharge pressure to compensate for downstream pressure changes. The fluid supply system comprises a variable displacement piston (VDP) pump configured to supply a fluid at a pump discharge pressure, fuel metering units (FMUs) downstream of the VDP pump, each of the FMUs configured to receive the fluid from the VDP pump at the pump discharge pressure and supply the fluid at metered flow discharge pressures, and a pump compensator valve fluidically coupled with the FMUs to receive the fluid therefrom at the metered flow discharge pressures and configured to continuously, either fluidically or mechanically, adjust the pump discharge pressure of the VDP pump between a higher of a minimum pump discharge pressure and a floating ceiling pump discharge pressure, the floating ceiling pump discharge pressure based on a highest of the metered flow discharge pressures.

Methods and fluid supply systems are provided for supplying fluids while adjusting a pump discharge pressure to compensate for downstream pressure changes. The fluid supply system comprises a variable displacement piston (VDP) pump configured to supply a fluid at a pump discharge pressure, fuel metering units (FMUs) downstream of the VDP pump, each of the FMUs configured to receive the fluid from the VDP pump at the pump discharge pressure and supply the fluid at metered flow discharge pressures, and a pump compensator valve fluidically coupled with the FMUs to receive the fluid therefrom at the metered flow discharge pressures and configured to continuously, either fluidically or mechanically, adjust the pump discharge pressure of the VDP pump between a higher of a minimum pump discharge pressure and a floating ceiling pump discharge pressure, the floating ceiling pump discharge pressure based on a highest of the metered flow discharge pressures.

In a fuel control system (10) for a gas turbine engine (1) having a gas generator (4) and a turbine (6) driven by the gas generator (4): a main fuel regulator (12) determines a demand (W.sub.fdem) of fuel flow (W.sub.f) to be introduced in the gas turbine engine (1), based on an input request (PLA); and a first limiter stage (14), operatively coupled to the main fuel regulator (12), causes an adjustment of the fuel flow (W.sub.f) based on engine safety operating limits. The first limiter stage (14) is provided with a Ngdot limiter (20) to cause an adjustment of the fuel flow (W.sub.f) when the gas generator speed rate of change (N.sub.gdot) is determined to overcome acceleration/deceleration scheduled safety limits; the Ngdot limiter (20) implements a predictor (23), to perform a prediction (W.sub.fdot) of the fuel flow rate of change (W.sub.fdot), or fuel flow (W.sub.f), allowing the gas generator speed rate of change (N.sub.gdot) to track a scheduled reference value (Ngdot.sub.ref).

In a fuel control system (10) for a gas turbine engine (1) having a gas generator (4) and a turbine (6) driven by the gas generator (4): a main fuel regulator (12) determines a demand (W.sub.fdem) of fuel flow (W.sub.f) to be introduced in the gas turbine engine (1), based on an input request (PLA); and a first limiter stage (14), operatively coupled to the main fuel regulator (12), causes an adjustment of the fuel flow (W.sub.f) based on engine safety operating limits. The first limiter stage (14) is provided with a Ngdot limiter (20) to cause an adjustment of the fuel flow (W.sub.f) when the gas generator speed rate of change (N.sub.gdot) is determined to overcome acceleration/deceleration scheduled safety limits; the Ngdot limiter (20) implements a predictor (23), to perform a prediction (W.sub.fdot) of the fuel flow rate of change (W.sub.fdot), or fuel flow (W.sub.f), allowing the gas generator speed rate of change (N.sub.gdot) to track a scheduled reference value (Ngdot.sub.ref).

A method for reducing an engine core speed is disclosed, which includes determining a condition of an engine during operation of the engine, and controlling an engine turbine clearance based on the condition of the engine so as to influence the engine core speed. An engine system comprising an engine core speed reducing system is also disclosed.

A method for reducing an engine core speed is disclosed, which includes determining a condition of an engine during operation of the engine, and controlling an engine turbine clearance based on the condition of the engine so as to influence the engine core speed. An engine system comprising an engine core speed reducing system is also disclosed.

The present disclosure relates to a system for supplying fuel to a turbomachine. In some embodiments, the system includes a pump, a hydromechanical group, a drive device positioned to drive the pump, and a branch comprising actuators for controlling variable geometry. In some embodiments, the system regulates a fuel flow rate based at least in part on a flow rate set point value. In some embodiments, the system may include a flow rate sensor. A flow rate loop may be arranged to determine a pressure set point value at the outlet of the pump according to the flow rate set point value and a measurement supplied by the flow rate sensor. In some embodiments, a pressure sensor may be positioned in the fuel circuit at the outlet of the pump. In further embodiments, a pressure loop may control the speed of the drive device based at least on a difference between a pressure measurement supplied by the pressure sensor and the pressure set point value.

The present disclosure relates to a system for supplying fuel to a turbomachine. In some embodiments, the system includes a pump, a hydromechanical group, a drive device positioned to drive the pump, and a branch comprising actuators for controlling variable geometry. In some embodiments, the system regulates a fuel flow rate based at least in part on a flow rate set point value. In some embodiments, the system may include a flow rate sensor. A flow rate loop may be arranged to determine a pressure set point value at the outlet of the pump according to the flow rate set point value and a measurement supplied by the flow rate sensor. In some embodiments, a pressure sensor may be positioned in the fuel circuit at the outlet of the pump. In further embodiments, a pressure loop may control the speed of the drive device based at least on a difference between a pressure measurement supplied by the pressure sensor and the pressure set point value.

An actuating device of a pump of a fuel pumping system of an engine, including a motor, a generator, an inverter, a switching member and a control member, the motor including a first rotor coupled to the pump and a first stator including at least one input stator winding, the generator including a second rotor coupled to a drive shaft of the engine, and a second stator including at least one output stator winding, the control member being configured to control the switching member in order to selectively connect each input stator winding: to a corresponding output stator winding if a speed of the engine is higher than or equal to a predetermined speed; to a corresponding output of the inverter, otherwise.