Low pressure fuel pump TNND UTN MTZ, YuMZ (UTN-3-1106010-A4), Kharkiv region.

Fuel pumpingpump is designed to ensure fuel supply from tanks to the fuel pump under pressure in order to overcome the hydraulic resistance of fuel filters. The pumping pump of the piston type with a flat pusher is driven from the eccentric neck of the camshaft of the fuelpump.

The priming pump is attached on the front side to the fuel pump housing. The design of the pump is shown in the image below. Fuel supply is carried out by a mechanical piston drive and a manual piston drive. Intake and discharge valves are kapron, mushroom type. When the fuel pump shaft rotates, the eccentric collides with the pusher, which moves the piston through the rod, while the springs of the pusher and the piston are compressed. In cavity "A", the fuel pressure increases, the inlet valve closes, and the discharge valve opens, fuel flows from cavity "A" into cavity "B" and partially enters the fine filter.
(//tractor-service.com)
After the piston reaches the extreme position, the discharge valve will close under the action of the spring. As the fuel is consumed, the engine piston under the action of the compressed spring will displace fuel from cavity "B" into the fine filter. At this time, a vacuum is created in cavity "A", the inlet valve opens and fuel from the tank will flow into cavity "A" through the filter sump.

A similar design of the pumping pump allows you to automatically adjust the amount of active stroke of the piston, i.e. amount of fuel supply. To fill the fuel system with fuel before starting the engine and remove air from ituse a pump manual fuel pumping. When the handle is moved up, a vacuum is created in the space above the piston, under the action of which the intake valve opens and fuel fills cavity "A" and the cylinder. When the handle is moved down, fuel pressure is created in the cylinder and cavity "A", under the action of which the intake valve closes, and the discharge valve opens, and fuel is fed to the fine filter and fuel pump.

UTN-3-1106010-A4, Weight - 1,176 kg.