Vickers plunger pump is a kind of reciprocating pump, which belongs to volumetric pump. Its plunger is driven by the eccentric rotation of the pump shaft to move back and forth, and its suction and discharge valves are both check valves. When the plunger is pulled out, the pressure in the working chamber decreases and the outlet valve closes. When the pressure is lower than the inlet pressure, the inlet valve opens and liquid enters; when the plunger is pushed in, the working chamber pressure rises and the inlet valve closes. When the pressure is higher than the outlet pressure, The outlet valve opens and the liquid is discharged. The axial piston pump with sliding shoe structure is a widely used axial piston pump. The plunger placed in the cylinder body is in contact with the swash plate through the sliding shoe. When the drive shaft drives the cylinder body to rotate, the swash plate will The plunger is pulled or pushed back from the cylinder to complete the oil suction and discharge process. The oil in the working cavity formed by the plunger and the cylinder bore is respectively communicated with the suction and discharge cavities of the pump through an oil distribution plate. The variable mechanism is used to change the inclination angle of the swash plate, and the pump displacement can be changed by adjusting the inclination angle of the swash plate.