Piston distributor — general information

From the rotary pump, fuel is pumped under pressure to the fuel pump. The distribution piston is installed in the pump on the same shaft as the rotary pump. It is the main unit of the pump and performs the functions of filling and injection. This happens as follows: when filling, the control slot of the piston is opposite the inlet hole. Fuel from the rotary pump under pressure enters the free cavity of the piston and flows into the free cavity of the piston and into the space in front of the piston. The control piston turns (through the gear at half the speed of the engine), and the filling space closes again.

Two more nodes are also involved in the operation of the pump. The distribution piston is connected to a disc having 4 cams. This cam rotates around a fixed bearing which, in order to reduce friction, has 4 rollers set at the same distance as the cams on the cam, i.e. The cam disc rotates on a roller ring. When the cams are rolled over the rollers, the cam disc, together with the control piston, is pressed axially forward. This happens exactly at the moment of injection, at which the next hole in the piston coincides with the outlet port for the injector. Fuel can thus be supplied to the cylinder in which compression has occurred. As the control piston moves forward, the volume in front of the piston simultaneously decreases and the pressurized fuel is further compressed and injected into the injector.

With a further turn of the fuel pump, the distribution piston returns back and a new portion of fuel enters the piston cavity from the filling hole and the process repeats.