Structure Principle of Electric Fuel Pump

Electric fuel pump on electronic injection automobiles is different from devices on non-electronic injection automobiles. Electric fuel pump is used to raise the pressure of gasoline and inject the gasoline into delivery pipe. Electric fuel pump consists of electromagnetic driving structure and oil supply structure. 

 

Structure principle of electric fuel pump 

Modern sedans utilize different gasoline injection system and fuel supply methods. However, all of them need electric fuel pump. The electric fuel pump must supply enough fuel having definite pressure to oil supply system.

 

For being limited by structure, mechanical diaphragm pump is far away from heat source. It can be only installed inline instead of horizon. Electric fuel pump can be installed at any positions and it cannot cause air resistance.

 

Electric fuel pump is composed of pump, permanent magnet motor and shell. Permanent magnet motor drives pump to rotate after being energized. Fuel is absorbed from inlet, passing through interior of pump and squeezed from outlet, supplying oil to fuel delivery system. The fuel cools the armature of permanent magnet motor. For this, electric fuel pump is also called as wet fuel pump.

 

The motor of electric fuel pump is made up of permanent magnet fixed on shell, armature causing electromagnetic torque and electric brush on shell. Electric brush contacts with commutator on armature. Its leads are connected with binding post on shell, transmitting voltage which controls electric fuel pump to armature winding.

 

Additional functions of fuel pump are realized by safety valves and one-way valves. Safety valves can prevent the pressure from rising excessively when oil way is blocked, in case of oil-way or fuel pump being damaged. One-way valves are used to seal oil-way when pump stops working. Residual voltage on oil system is maintained so that engine can be started easily in the next time.