The work of the piston moving in the reciprocating motion of a hydraulic piston pump is converted into pressure, which is used to overcome external loads through the driving fluid. Axial piston pumps have an odd number of pistons that move within cylinders installed in the pump body. The rotating cylinder is driven by a shaft and generates reciprocating motion of the piston through the contact between the rotating inclined plate and the piston slipper. The piston absorbs oil from the intake port and then squeezes the fluid to generate pressure, thereby driving the oil into the high-pressure port. Piston pumps can have variable or fixed displacement. The fluid is controlled by a reversing unit. The efficiency of a fixed displacement pump is determined by the number and size of pistons, as well as the length of the stroke, which in turn depends on the angle of the rotating swash plate.

 

Automatic variable displacement piston pump is used for load sensing and has power limit control of hydraulic variable displacement pump. The pump operation mode will be based on the pump discharge power for pressure control or displacement control. The main problem studied in this article is to combine two schemes to achieve a stable and smooth transition between the two control modes. In order to achieve a smooth transition, the proposed algorithm is used to obtain the continuity of the controller output on the power limit boundary. Realize the stability of the control system through control design. Smooth bidirectional transmission between displacement control and power control modes has been achieved. The provided control design significantly simplifies the fluid dynamics design of variable displacement pumps and reduces pump costs while improving performance. The experimental results validated the theoretical development.


The above:Where does a piston pump function?