Fuel pump

A fuel pump is used to transport the fuel in the required amount and with the necessary pressure from the fuel tank to the carburetors, injectors and injection pumps of internal combustion engines or jet engines, unless they are powered by a case Fuel System.

Construction

Apart from conventional diesel systems and part of the diesel common rail systems of the "first " generation that still work with mechanically driven by the engine displacement, today's fuel pumps are electrically powered and are located in the fuel tank. The electric drive is aware not separated from fuel but is flowing through this. This ensures optimal cooling and lubrication of the electric fuel pump. A fire caused by sparks or overheating is not the case, because the relevant parts of air is displaced by the fuel.

Species

There are both current pumps (Peripheral or side channel principle ) and displacement ( or gerotor gear, roller-cell principle), the former mainly for gasoline main and pre-delivery, the latter for diesel pre. The delivery rate depends strongly on the internal combustion engine to be supplied and the tank components from (eg suction jet pumps with saddle tanks) and is usually between 80 and 250 l / h at an operating pressure of 3 to 7 bar. Carburettor engines whose tank can be at the same or lower level compared to the float chamber level, self-regulating diaphragm pumps are used with discharge pressures from 0.15 to 0.40 bar in the rule.

Reliability

Since a failure of the fuel pump inevitably leads to a stop of the vehicle, an extremely high reliability is required, with fail-safe operation period 5000-10000 hours. Especially for alternative motor fuels to ethanol or methanol base, but also for all diesel fuels ( here again, especially for the so-called biodiesel RME base ) represents the significant challenge Although an electric motor with electronic commutation (brushless motor ) is the ideal solution, was for cost reasons, the classical commutator motor ( brush motor ) developed evolutionarily. The development objective was achieved by the transition to a commutator of graphite instead of copper.