sensors introductionPlunger type electric fuel pump
Because of the high cost of electric centrifugal booster pumps, many small single wing aircraft's fuel systems use electric plunger pumps as auxiliary fuel pumps for fuel systems. The plunger pump is usually installed in parallel with the engine driven diaphragm fuel pump in order to supply fuel to the engine individually or jointly.
The plunger fuel pump belongs to the pulsating pump. It consists of a South electromagnetic coil, a plunger, a calibrating spring and 2 one-way valves (net 9 - 14). The electromagnetic coil is wound around a brass tube that connects 2 oil cavities. The spring of the calibrating spring pushes upward to the plunger, and the electromagnetic force of the coil pushes down the plunger. A one-way valve is installed in the middle of the plunger part, and the other is installed in the middle of the bottom of the brass pipe extension section of the oil inlet chamber.
When the plunger pump is not energized, calibrating the spring force pushes the plunger upward along the brass tube, and the plunger will attract the magnet to touch the contacts through the pivot. After energizing, the current flows through the electromagnetic line through the contacts to generate electromagnetic force, and the plunger is sucked downward into the coil part. At this point, the fuel in the B chamber passes through the one-way valve to the upper flow plunger. When the plunger is moved to the middle of the electromagnetic coil, it will no longer attract the magnet, the contact will skip, and the electromagnetic coil will be cut off. The electromagnetic force disappears. At this time, the calibrating spring pushes the plunger, and the C chamber fuel is extruded to feed the engine. At the same time, the fuel from the fuel tank is pumped into the A chamber, and then enters the B cavity through the bottom one way valve to prepare for the next oil supply cycle.
If the engine receives all the output of the pump, the pump pulsating frequency is very high, but if the engine vaporizer shutter shutter is closed, or the fuel between the carburetor and the pump is under pressure, the pump will be in a low speed pulsation state.