50 years of uninterrupted fuel supply: Bosch electric fuel pumps

• The electric fuel pump was developed for the electronic system of gasoline injection Jetronic more than 50 years ago
• Modern fuel pumps are part of a submersible fuel module
• Bosch fuel pumps provide high performance, safety and long service life

Before the invention and introduction of the electronic injection system, the mechanical fuel pump was able to cope with the function of supplying fuel to the engine. Despite the fact that Bosch's petrol injection system appeared in the early 50's of the last century and was used, in particular, on the legendary Mercedes 300 SL in 1954, the development of electronic control for it began only in 1959. To start the system on the market it took another six years, during which time  an electric fuel pump was developed too on the basis of a five-sector roller pump for a liquid fuel burner and an electric motor with a permanent magnet. This technology soon found its application in D-Jetronic injection systems with intake manifold pressure control. In 1967, Bosch launched the world's first electronic injection system Jetronic in mass production.

Further improvement of the design of the electric fuel pump went in parallel with the improvement of the systems of petrol and diesel injection. So, in 1979 Bosch introduces a fuel pump to the market that allows creating high pressure and providing sufficient performance of the L-Jetronic petrol injection systems with air flow measurement and mechanical-hydraulic K-Jetronic. The next milestone in the history of the development of Bosch fuel pump technologies was the launch of a centrifugal pump in series production in 1985. This event marked the end of the monopoly of the roller pump.

At the dawn of the application of electronic injection systems, electric fuel pumps were installed exclusively outside the fuel tank in the fuel line. Today, the pumps are mainly located inside the tank, that is, they are submersible. In this case, they enter the submersible fuel module, which is also called the fuel supply module. Such submersible fuel modules can be equipped with additional functions, for example, a filter or an electronic control unit.

In all operating conditions, the electric fuel pump must provide the engine with sufficient fuel under the required pressure. In addition, such a pump is increasingly being used as a fuel-pumping for fuel pumps for high-pressure modern systems with direct injection on both gasoline and diesel engines. Bosch electric fuel pumps have a capacity from 50 to 250 l / h at a nominal voltage, provide a pressure in the fuel system from 50 to 750 kPa (0.5-7.5 bar) and operating pressure in the system at a voltage of already 50% of the nominal.  The last parameter is a critical factor of the system's operability at a cold start. In addition, the design of Bosch pumps and fuel modules guarantees the driver a high level of safety through various safety devices such as a fuel cutoff valve and a pressure limiting valve.

Today, Bosch offers solutions for fuel delivery systems from  tanks of complex shaped. Such systems are necessary in the case when, due to the peculiarities of the fuel tank design, its entire volume is not available directly. This applies, for example, to saddle type tanks, section tanks or to elongated flat-shaped tanks. Fuel supply from such remote tanks is carried out either in an active way by means of jet pumps (Venturi effect), or passively by lowering the pressure in the fuel module itself. It is used in cars of brands BMW, Mercedes-Benz, Volvo, Ford, Opel and others.