The upper part of the plunger has an annular groove, which communicates with the upper end surface of the plunger through a longitudinal groove. The spiral bevel starts from the longitudinal groove to adjust the oil 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 is freely installed on the plunger sleeve. The open gear ring is fastened on the rotating sleeve with screws, and meshes with the gear rod.
The gear rod is installed in the longitudinal hole of the pump body and connected with the governor control rod. When the gear rod moves axially under the action of the joystick and the governor, the rotating sleeves and plungers on each oil pump also rotate to a certain angle. The plunger flange is equipped with a lower bearing plate of the plunger spring. The upper spring bearing plate is supported on the pump body. The function of the spring is to move the plunger down. The cam on the camshaft acts on the plunger through the roller body to make it move upward.
The roller body is the transmission body between the cam and the plunger. It itself bears the side thrust and the plunger only receives axial force. The lower shaft of the roller body is equipped with a roller, which is mounted on a needle bearing, and the upper end of the roller body is screwed with an adjusting screw and a safety nut.