Fuel pump — design description

Fuel pump rotary, submersible type with electric drive, manufactured by «Bosch» (Germany), installed in the right half of the fuel tank. The fuel supply pressure at a voltage of 12 V at the AB terminals is 4.0 kgf/cm².

The fuel pump rotor is mounted eccentrically on the permanent magnet motor shaft. In the chambers located around the circumference of the rotor, there are metal rollers, which, under the action of centrifugal forces, are pressed against the surface of the pump casing, providing a reliable seal. The fuel sucked into the gaps between the rollers and the pump housing is fed into the discharge pipe. The installed check valve closes the fuel supply channel. As soon as the fuel pressure exceeds 4.0 bar (kgf/cm²), the safety valve ball closes the fuel supply from the tank.

To maintain the required fuel pressure in the power system, the fuel pump delivers an amount of fuel that exceeds its consumption by the engine. So in full load mode, about 70% of the injected fuel is drained into the tank, after passing through the pressure regulator. The fuel pressure regulator of the fuel injection system is set to 3.5 bar (kgf/cm²). The working pressure of the suction jet pump is 1.0-1.3 bar (kgf/cm²).

The performance of the pump at a voltage of 12 V at the AB terminals is 2.06 l/min. The consumed current at a voltage at the terminals of the AB 12 V is not more than 9.5A.