Snecma

Bastien Dore

Nicolas Alain Bader

Frédéric Brettes

Laurent Gilbert Yves Hodinot

Laurent Gilbert Hodinot

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.

Fuel feed circuit with hydraulic actuator and fuel metering unit for an aeroengine

A jet pump () is inserted between the low-pressure pump and a high-pressure fuel pump (). A fuel metering unit () includes a metering valve () which delivers a regulated fuel flow to a feed line (), and a bypass valve () which diverts to a primary intake () of the jet pump the excess fuel flow supplied by the high-pressure pump. An overspeed protection unit () includes a control element () of the bypass valve () which causes said to fully open in the event of an overspeed of the engine. A shutoff and pressurization checkvalve () is mounted on the feed line and controlled by a servo-valve () having a high-pressure port () brought to the high fuel pressure, a low-pressure port brought to the pressure of the primary intake () of the jet pump and an output setting the pressure in a control chamber () of the shutoff valve () to a value between those prevailing at the high pressure and low pressure ports. In the event of overspeed, the restriction imposed by the jet pump causes a pressure rise at the primary intake of the jet pump, hence a pressure rise in the control chamber of the shutoff valve (), favoring the closing thereof.

Growing community of inventors

Paris, France

Bastien Dore