Description of the working principle of the foreign piston pump

1 plunger pump works
The plunger pump is an important device for the hydraulic system. It relies on the plunger to reciprocate in the cylinder to change the volume of the sealing working chamber to achieve oil absorption and oil pressure. The plunger pump has the advantages of high rated pressure, compact structure, high efficiency and convenient flow adjustment. It is widely used in high pressure, large flow and flow adjustment situations, such as hydraulic machines, construction machinery and ships.

The plunger pump is a kind of reciprocating pump, belonging to a volume pump, the plunger is driven by the eccentric rotation of the pump shaft, reciprocating, and the suction and discharge valves are both one-way valves. When the plunger is pulled out, the pressure in the working chamber is lowered, the outlet valve is closed, when the inlet pressure is lower, the inlet valve is opened, and the liquid enters; when the plunger is pushed, the pressure of the working chamber is increased, and the inlet valve is closed, higher than the outlet pressure. The outlet valve opens and the liquid drains. When the drive shaft drives the cylinder to rotate, the swash plate pulls or pushes the plunger out of the cylinder to complete the suction and discharge process. The oil in the working volume formed by the plunger and the cylinder hole communicates with the suction and discharge chambers of the pump through the oil distribution plate. The variable mechanism is used to change the inclination of the swash plate, and the displacement of the pump can be changed by adjusting the inclination of the swash plate.

2 plunger pump structure
The plunger pump is divided into two representative structures: an axial piston pump and a radial piston pump; since the radial piston pump belongs to a new type of high-efficiency high-efficiency pump, with the acceleration, the radial direction Piston pump will inevitably become an important part of the application of plunger pump.

3 plunger pump maintenance
The swash plate type axial piston pump generally adopts the form of cylinder rotation and end face distribution. The end face of the cylinder body is embedded with a friction pair composed of a bimetal plate and a steel oil distribution plate, and most of them adopt a plane distribution method, so the maintenance is convenient. The oil distribution plate is one of the key components of the axial piston pump. When the pump is working, on the one hand, the high pressure oil of the working chamber pushes the cylinder to the oil distribution plate, and on the other hand, the oil film pressure between the oil distribution plate and the cylinder body forms a pair. The hydraulic reverse thrust of the cylinder causes the cylinder to face away from the oil distribution plate. The hydraulic pressing force Fn of the cylinder to the oil distribution plate is slightly larger than the hydraulic reverse thrust Ff of the oil distribution plate to the cylinder block, that is, Fn/Ff=1.05~1.1, so that the pump works normally and maintains high volumetric efficiency.