The synthetic pump is equipped with the same number of plunger and cylinders in the same pump body. Each cylinder has a set of fuel injection elements, which are driven by the corresponding cams of the camshaft in the pump body.
Now take out a pump set from the integral fuel injection pump for description. The structure is as follows: Its main parts are: camshaft, roller body, plunger and plunger sleeve, plunger spring, rotating sleeve and ring gear, delivery valve and valve seat, and compression pipe connection. The plunger sleeve and the plunger are a pair of main precision parts in the fuel injection pump. They are carefully processed and matched with each other. Their diameter gap is only 0.001-0.003mm. This pair of parts can only be replaced in pairs, not individually.
There are two holes on the plunger sleeve to make the inner cavity of the plunger sleeve communicate with the oil passage, and there is a longitudinal groove at the right oil hole, in which screws are inserted, so that the plunger sleeve is fixed in the pump body and cannot be rotated.