An electric fuel pump is a device that continuously sucks fuel out of the tank and provides fuel with a specified pressure and flow rate to the fuel system. Based on the function of electric fuel pump, it can be seen that the performance of electric fuel pump will directly affect the performance of engine.
The electric fuel pump is the heart of the fuel supply system of the electric injection engine. There are two kinds of arrangement of electric fuel pump in the oil supply system. One is external type, that is, the fuel pump is connected in series in the oil pipeline outside the tank. The second is the built-in type, that is, the fuel pump is installed in the fuel tank, immersed in gasoline, so the fuel pump is easy to heat, small noise, long service life, so it is widely used.
The working principle of
Electric fuel pump consists of pump body, DC motor and shell. Its basic working principle is that the rotor in the pump housing is driven to rotate at high speed after the DC motor is energized. The section of the lower end of the rotor shaft is combined with the section of the inner hole of the impeller, so that when the rotor rotates, the impeller is driven to rotate in the same direction through the rotor shaft. During the high-speed rotation of the impeller, vacuum low pressure is caused in the oil inlet part. Then the filtered fuel is inhaled from the inlet of the pump cover, and the inhaled fuel is pressurized by the fuel pump impeller into the interior of the pump shell and then pressed out through the oil outlet, providing fuel with a certain pressure for the fuel system. The structure of the DC motor includes a permanent magnet fixed on the inner wall of the pump shell, a rotor that can generate a magnetic moment after energized, and a graphite carbon brush assembly installed on the upper end of the pump shell. The carbon brush is in elastic contact with the commutator on the armature rotor, and its lead is connected to the plug-in wiring electrode of the shell. The two ends of the outer shell of the electric fuel pump are riveted by crimping, becoming a non-removable assembly.
