The plunger mud pump is a new type of high-efficiency pump with relatively high technical content. With the continuous acceleration of localization, the radial plunger pump will inevitably become an important part of the application field of the plunger pump; see the radial plunger for details. Pump Encyclopedia; the following only takes the axial piston pump as an example for explanation.

The axial plunger pump uses the volume change produced by the reciprocating movement of the plunger parallel to the drive shaft in the plunger hole to work. Because the plunger and the plunger hole are both circular parts, they can achieve high precision during processing, so they have the advantages of high volumetric efficiency, stable operation, good flow uniformity, low noise, and high working pressure. The pollution is more sensitive, the structure is more complicated, and the cost is higher.

The oil pumping mechanism of the plunger pump manufacturer includes two sets of precision coupling parts: plunger + plunger sleeve constitutes the plunger coupling part, and the delivery valve and the delivery valve seat constitute the delivery valve assembly. The plunger and the plunger sleeve are a pair of Precision coupling parts that cannot be interchanged after pairing and grinding. High precision, smoothness, and good wear resistance are required. The radial clearance is 0.002～0.003mm.

An oblique groove is cut on the cylindrical surface of the plunger head and communicates with the top through a radial hole and an axial hole. The purpose is to change the circulating oil supply; the plunger sleeve is provided with an oil inlet and return holes connected to the pump. The low-pressure oil chamber in the body communicates with each other. After the plunger is inserted into the upper body of the pump, the positioning screw is used for positioning.

The position of the chute on the plunger head is different, and the method of changing the oil supply is also different.

The oil outlet valve and the oil outlet valve seat are also a pair of precision parts, which cannot be interchanged after being matched and ground. The fit clearance is 0.01mm.

The oil outlet valve is a one-way valve. Under the action of spring pressure, the upper conical surface of the valve closely matches the valve seat. Its function is to isolate the high-pressure oil pipe from the cavity at the upper end of the plunger when the supply is stopped to prevent oil in the high-pressure oil pipe. It flows back into the fuel injection pump.

The lower part of the delivery valve is a cross-section, which can guide and pass diesel oil. There is a small cylindrical surface under the conical surface of the oil outlet valve, called a pressure relief ring, whose function is to make the oil pressure in the high-pressure oil pipe drop rapidly at the end of the oil supply to avoid oil dripping at the nozzle hole. When the annulus falls into the valve seat, the upper volume increases rapidly, the pressure decreases rapidly, and the spray stops quickly.