What is usually employed in a two-stage engine-driven fuel pump?

In a two-stage engine-driven fuel pump, the typical configuration involves a centrifugal pump that supplies fuel to a gear-type pump. The centrifugal pump is efficient at moving larger volumes of fuel at lower pressures, making it ideal for the initial stage of pumping. It uses rotational energy to create flow, effectively handling fuel supply under varying engine conditions.

Following the centrifugal pump, the gear-type pump takes over to provide higher pressure necessary for delivering fuel to the engine at the required flow rates. Gear pumps are positive displacement devices that can maintain consistent pressure and flow, which is critical for engine performance, especially in high-demand scenarios.

This two-stage design leverages the strengths of both pump types to ensure a reliable and efficient fuel delivery system. The centrifugal pump handles the bulk flow, while the gear pump ensures that the fuel pressure is adequate for the engine’s needs.