Abstract: A fuel metering unit comprising a movable element including at least one fuel flow section opening upstream towards a fuel supply duct and opening downstream towards a utilization duct through a metering slot with a flared profile having a narrow flow section and a wide flow section, the movable element able to be moved with respect to a stationary element between a low flow rate position and a high flow rate position, the metering slot made in the stationary element or in the movable element and its obstruction obtained by covering the slot with a wall of the movable element or of the stationary element.

Abstract: A fuel metering unit comprising a movable element including at least one fuel flow section opening upstream towards a fuel supply duct and opening downstream towards a utilization duct through a metering slot with a flared profile having a narrow flow section and a wide flow section, the movable element able to be moved with respect to a stationary element between a low flow rate position and a high flow rate position, the metering slot made in the stationary element or in the movable element and its obstruction obtained by covering the slot with a wall of the movable element or of the stationary element.

Abstract: A fuel metering unit including a movable element including at least one fuel passage section opening upstream towards a fuel supply conduit and opening downstream towards a conduit of use through a metering slot with a flared profile having a narrow passage section flaring as far as a wide passage section, the movable element being able to be moved with respect to a fixed element between a low flow rate position in which the metering slot is for a large part obstructed and a high flow rate position in which the metering slot is for a large part exposed, the metering slot being made in the fixed element or in the movable element and its obstruction being obtained by covering the slot with a wall of the movable element or of the fixed element.

Abstract: A fuel metering unit including a movable element including at least one fuel passage section opening upstream towards a fuel supply conduit and opening downstream towards a conduit of use through a metering slot with a flared profile having a narrow passage section flaring as far as a wide passage section, the movable element being able to be moved with respect to a fixed element between a low flow rate position in which the metering slot is for a large part obstructed and a high flow rate position in which the metering slot is for a large part exposed, the metering slot being made in the fixed element or in the movable element and its obstruction being obtained by covering the slot with a wall of the movable element or of the fixed element.

Abstract: A fuel supply device includes a fuel supply pipe receiving fuel at a non-regulated pressure delivered by a pump, a device for measuring the flow rate of fuel in the pipe, a first controlled variable-restriction valve mounted in the supply pipe, a control system connected to the flow rate measurement device and to the first valve to control the valve to deliver fuel to the engine at a desired flow rate under normal operating conditions of the engine, a second controlled variable-restriction valve mounted in the supply pipe in series with the first valve, and a control for controlling the second valve to enable the engine to be supplied with fuel at an adjustable, reduced flow rate in response to detecting over-speed or over-thrust of the engine.

Abstract: A centrifugal pump driven by mechanical coupling with an engine has a low pressure inlet receiving fuel from a fuel circuit of an aircraft, a high pressure outlet connected to a regulator circuit for regulating the flow rate of fuel supplied to the engine, and an assistance pump unit that is electrically controlled, having an inlet connected to the aircraft fuel circuit and an outlet connected to the flow rate regulator circuit so as to deliver, via its outlet, fuel that is at a predetermined minimum pressure, the pressure of the fuel supplied to the regulator circuit being the higher of the pressures delivered by the centrifugal pump and the assistance pump unit.

Abstract: A centrifugal pump driven by mechanical coupling with an engine has a low pressure inlet receiving fuel from a fuel circuit of an aircraft, a high pressure outlet connected to a regulator circuit for regulating the flow rate of fuel supplied to the engine, and an assistance pump unit that is electrically controlled, having an inlet connected to the aircraft fuel circuit and an outlet connected to the flow rate regulator circuit so as to deliver, via its outlet, fuel that is at a predetermined minimum pressure, the pressure of the fuel supplied to the regulator circuit being the higher of the pressures delivered by the centrifugal pump and the assistance pump unit.

Abstract: A fuel supply device includes a fuel supply pipe receiving fuel at a non-regulated pressure delivered by a pump, a device for measuring the flow rate of fuel in the pipe, a first controlled variable-restriction valve mounted in the supply pipe, a control system connected to the flow rate measurement device and to the first valve to control the valve to deliver fuel to the engine at a desired flow rate under normal operating conditions of the engine, a second controlled variable-restriction valve mounted in the supply pipe in series with the first valve, and a control for controlling the second valve to enable the engine to be supplied with fuel at an adjustable, reduced flow rate in response to detecting over-speed or over-thrust of the engine.

Abstract: The actuator assembly comprises a master actuator and at least one slave actuator having a cylinder containing a piston defining two chambers in the cylinder. A first chamber of the slave actuator is connected to an outlet of a directional control valve which is connected to a hydraulic control circuit and to a control member whose position determines the pressure in the first chamber of the slave actuator. A displacement of the piston of the master actuator is transferred to the control member of the control valve associated with the slave actuator by means of a mechanical transmission such as a flexible linear rolling bearing. Thus, the displacement of the piston of the slave actuator is servo-controlled to the displacement of the piston of the master actuator by controlling the position of the control member of the control valve associated with the slave actuator.

Abstract: An aircraft engine fuel supply circuit includes a high pressure pump for supplying the engine fuel injectors and supplying a plurality of servovalves for operating various auxiliary mechanisms. In an in-flight re-ignition configuration, with the rotational speed of the engine drops below a threshold value, a fuel economizer valve receives a command to close, thereby shutting off the supply of high pressure fuel to the servovalves. Consequently, the dimensions of the high pressure pump and other associated components in the circuit, especially heat exchangers, may be reduced.

Abstract: The servovalve comprises an electric motor and a distributor valve integrating a hydraulic slide under the control of said electric motor and further comprising two load channels pierced in a central rod on which blocks are mounted for co-operating with communication orifices of the distributor valve and co-operating with one another and with the ends of the hydraulic slide to define annular chambers including two load chambers connected to the receiver member to be controlled. The two load channels put each of the load chambers into communication respectively with an immediately adjacent annular chamber so as to ensure that the same pressure exists on both sides of the blocks separating said two chambers.

Abstract: The actuator assembly comprises a master actuator and at least one slave actuator having a cylinder containing a piston defining two chambers in the cylinder. A first chamber of the slave actuator is connected to an outlet of a directional control valve which is connected to a hydraulic control circuit and to a control member whose position determines the pressure in the first chamber of the slave actuator. A displacement of the piston of the master actuator its transferred to the control member of the control valve associated with the slave actuator by means of a mechanical transmission such as a flexible linear rolling bearing. Thus, the displacement of the piston of the slave actuator is servo-controlled to the displacement of the piston of the master actuator by controlling the position of the control member of the control valve associated with the slave actuator.

Abstract: A device for controlling fuel pressure and delivery as necessary for the operation of the servovalves of an aircraft engine is disposed downstream of a fuel injector feed unit of the engine. The device comprises a chamber maintained at the servovalve feed pressure by the movement of a closure member to vary the opening of a port of the chamber. The closure member moves under the action of opposing forces comprising inter alia a force in the opening direction proportional to the servovalve feed pressure. An equilibrium position of the closure member is a function of pressure resulting from the engine speed. An injector delivery control loop is therefore isolated from a servovalve pressure and delivery control loop.

Abstract: A device for controlling fuel pressure and delivery as necessary for the operation of the servovalves of an aircraft engine is disposed downstream of a fuel injector feed unit of the engine. The device comprises a chamber maintained at the servovalve feed pressure by the movement of a closure member to vary the opening of a port of the chamber. The closure member moves under the action of opposing forces comprising inter alia a force in the opening direction proportional to the servovalve feed pressure. An equilibrium position of the closure member is a function of pressure resulting from the engine speed. An injector delivery control loop is therefore isolated from a servovalve pressure and delivery control loop.

Abstract: A device for controlling fuel pressure and delivery as necessary for the operation of the servovalves of an aircraft engine is disposed downstream of a fuel injector feed unit of the engine. The device comprises a chamber maintained at the servovalve feed pressure by the movement of a closure member to vary the opening of a port of the chamber. The closure member moves under the action of opposing forces comprising inter alia a force in the opening direction proportional to the servovalve feed pressure. An equilibrium position of the closure member is a function of pressure resulting from the engine speed. An injector delivery control loop is therefore isolated from a servovalve pressure and delivery control loop.

Abstract: The servovalve comprises an electric motor and a distributor valve integrating a hydraulic slide under the control of said electric motor and further comprising two load channels pierced in a central rod on which blocks are mounted for co-operating with communication orifices of the distributor valve and co-operating with one another and with the ends of the hydraulic slide to define annular chambers including two load chambers connected to the receiver member to be controlled. The two load channels put each of the load chambers into communication respectively with an immediately adjacent annular chamber so as to ensure that the same pressure exists on both sides of the blocks separating said two chambers.

Abstract: A hydraulic fuel control unit (100) for an aircraft engine comprises means (14, 2, 16) for controlling cutoff on stop and cutoff on overspeed of a fuel flow transferred by an output (1) to the engine injectors. A logic module (140) controls the position of a state switch (121, 143) into a test position or a normal position. The state module is managed such that the operation of the overspeed module can be tested each time the system is started on the ground. The architecture of the hydraulic unit (100) is such that operation of the cutoff on stop can be tested during each landing. Correct operation in the overspeed test and in the cutoff on stop test is observed by detecting a difference between a control value (153) of an allowable fuel flow that depends mainly on the engine speed, and a real flow value detected by sensors (22).

Abstract: An aircraft engine fuel supply circuit includes a high pressure pump for supplying the engine fuel injectors and supplying a plurality of servovalves for operating various auxiliary mechanisms. In an in-flight re-ignition configuration, with the rotational speed of the engine drops below a threshold value, a fuel economizer valve receives a command to close, thereby shutting off the supply of high pressure fuel to the servovalves. Consequently, the dimensions of the high pressure pump and other associated components in the circuit, especially heat exchangers, may be reduced.

Abstract: A fuel valve for a fuel flow injection circuit, operating on electrical energy rather than hydraulic energy. The fuel valve has a valve body, a first fuel inlet opening, and a distribution assembly having a plug rotating in a bushing, the plug and bushing each having an opening slit. The valve body includes a fuel outlet opening section made by an overlapping area between the opening in the bushing and the opening in the plug. A plug position unit is provided to control a position of the plug in rotation, and the plug position unit is disposed in the valve body. The valve body further contains an electric motor that drives a rotation of a reduction gear assembly, the reduction gear assembly comprising an input shaft and an output pinion. The plug comprises a toothed sector engaging on the splines of the reduction gear assembly output pinion such that rotating the electric motor causes a rotation of the plug.

Abstract: A device for controlling fuel pressure and delivery as necessary for the operation of the servovalves of an aircraft engine is disposed downstream of a fuel injector feed unit of the engine. The device comprises a chamber maintained at the servovalve feed pressure by the movement of a closure member to vary the opening of a port of the chamber. The closure member moves under the action of opposing forces comprising inter alia a force in the opening direction proportional to the servovalve feed pressure. An equilibrium position of the closure member is a function of pressure resulting from the engine speed. An injector delivery control loop is therefore isolated from a servovalve pressure and delivery control loop.