Abstract: A fuel feed circuit for an aeroengine, the circuit including a high-pressure pumping system including first and second positive displacement pumps, a hydraulic actuator, and a fuel metering unit. As a function of a position of a slide of the actuator, a feed orifice of the actuator may be connected to a high-pressure delivery orifice connected to an outlet of the second pump, or to a low-pressure delivery orifice connected to a low-pressure feed line. The fuel metering unit includes through sections, one of these through sections being connected to an outlet of the high-pressure pumping system and the other through section being connected to an outlet of the high-pressure pumping system and leading to a high-pressure pilot chamber of the hydraulic actuator.

Abstract: A jet pump (14) is inserted between the low-pressure pump and a high-pressure fuel pump (16). A fuel metering unit (20) includes a metering valve (22) which delivers a regulated fuel flow to a feed line (30), and a bypass valve (24) which diverts to a primary intake (14a) of the jet pump the excess fuel flow supplied by the high-pressure pump. An overspeed protection unit (50) includes a control element (54) of the bypass valve (24) which causes said to fully open in the event of an overspeed of the engine. A shutoff and pressurization checkvalve (42) is mounted on the feed line and controlled by a servo-valve (44) having a high-pressure port (44a) brought to the high fuel pressure, a low-pressure port brought to the pressure of the primary intake (14a) of the jet pump and an output setting the pressure in a control chamber (42a) of the shutoff valve (42) to a value between those prevailing at the high pressure and low pressure ports.

Abstract: A fuel feed circuit for an aeroengine, the circuit including a high-pressure pumping system including first and second positive displacement pumps, a hydraulic actuator, and a fuel metering unit. As a function of a position of a slide of the actuator, a feed orifice of the actuator may be connected to a high-pressure delivery orifice connected to an outlet of the second pump, or to a low-pressure delivery orifice connected to a low-pressure feed line. The fuel metering unit includes through sections, one of these through sections being connected to an outlet of the high-pressure pumping system and the other through section being connected to an outlet of the high-pressure pumping system and leading to a high-pressure pilot chamber of the hydraulic actuator.

Abstract: A jet pump (14) is inserted between the low-pressure pump and a high-pressure fuel pump (16). A fuel metering unit (20) includes a metering valve (22) which delivers a regulated fuel flow to a feed line (30), and a bypass valve (24) which diverts to a primary intake (14a) of the jet pump the excess fuel flow supplied by the high-pressure pump. An overspeed protection unit (50) includes a control element (54) of the bypass valve (24) which causes said to fully open in the event of an overspeed of the engine. A shutoff and pressurization checkvalve (42) is mounted on the feed line and controlled by a servo-valve (44) having a high-pressure port (44a) brought to the high fuel pressure, a low-pressure port brought to the pressure of the primary intake (14a) of the jet pump and an output setting the pressure in a control chamber (42a) of the shutoff valve (42) to a value between those prevailing at the high pressure and low pressure ports.