The main components of the oil pump include: camshaft, roller body, plunger and plunger sleeve, plunger spring, rotating sleeve and gear ring, outlet valve and valve seat, and compression pipe joint. The plunger sleeve and plunger are a pair of main precision components in the fuel injection pump. They have been carefully machined and matched with each other, with a diameter gap of only 0.001-0.003mm. These parts can only be replaced in pairs and cannot be replaced separately.
There are two holes on the plunger sleeve, which connect the inner cavity of the plunger sleeve with the oil passage. There is a longitudinal groove at the right oil hole, in which a screw is inserted to fix the plunger sleeve in the pump body and prevent it from rotating.
The upper part of the plunger has an annular groove, which is connected to the upper end face of the plunger through a longitudinal groove. The spiral bevel starts from the longitudinal groove and is used to adjust the fuel supply. The lower part of the plunger has two shoulders and flanges. The plunger shoulder is inserted into the incision of the rotating sleeve. The rotating sleeve can be freely installed on the plunger sleeve. The open ring gear is fastened to the rotating sleeve with screws and meshes with the toothed rod.
The gear rod is installed in the longitudinal hole of the pump body and connected to the governor control rod. When the gear rod moves axially under the action of the control rod and the governor, the rotating sleeve and plunger on each oil pump also rotate a certain angle accordingly. A lower bearing plate with a plunger spring installed on the plunger flange. The spring bearing plate is supported on the pump body. The function of a spring is to make the plunger descend. The cam on the camshaft acts on the plunger through the roller body, causing it to move upward.
The roller body is the transmission body between the cam and the plunger, which itself bears lateral thrust while the plunger only experiences axial force. The lower shaft of the roller body is equipped with a roller, which is mounted on the needle roller bearing. The upper end of the roller body is screwed with adjustment screws and safety nuts.