Rexroth hydraulic pump is an important component of construction machinery equipment and the core part of providing power, which greatly improves work efficiency and quality. The Rexroth hydraulic pump is also the power mechanism of the hydraulic system, which converts the mechanical energy of the prime mover (motor, internal combustion engine, etc.) into the pressure energy of the liquid. Rexroth pumps can be divided into two types: positive displacement and non positive displacement (worm gear). Non volumetric centrifugal pumps, axial flow pumps, etc. use high-speed rotating impellers to make the vacuum inhaler inlet and continuously output pressure liquid at the outlet. The pump inlet and outlet are connected, and the efficiency decreases with the increase of liquid viscosity, and the output liquid volume significantly decreases with the increase of outlet pressure. Positive displacement pumps achieve oil suction and pressure by changing the volume of enclosed spaces. When the closed volume increases from a small amount to a large amount, the oil is absorbed and the oil is pressurized by a large change in time. A typical example is a Rexroth plunger pump, where the plunger sucks oil when it is pulled out of the cylinder hole and presses it in. The efficiency of separating the inlet and outlet of the pump depends on the structure and process clearance between the separating suction chamber and the moving parts of the lubricating oil viscosity.