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Driving a hydraulic cylinder directly by a closed-loop hydraulic pump is currently a key research area in the field of electro-hydraulic control technology,and it is the most direct means to improve the energy efficiency of an electro-hydraulic control system.So far,this technology has been well applied to the pump-controlled symmetric hydraulic cylinder.However,for the differential cylinder thai is widely used in hydraulic technology,satisfactory results have not yet been achieved,due to the asymmetric flow constraint.Therefore,based on the principle of the asymmetric valve controlled asymmetric cylinder in valve controlled cylinder technology,an innovative idea for an asymmetric pump controlled asymmetric cylinder is put forward to address this problem.The scheme proposes to transform the oil suction window of the existing axial piston pump into two series windows.When in use,one window is connected to the rod chamber of the hydraulic cylinder and the other is linked with a low-pressure oil tank.This allows the differential cylinders to be directly controlled by changing the displacement or rotation speed of the pumps.Compared with the loop principle of offsetting the area difference of the differential cylinder through hydraulic valve using existing technology,this method may simplify the circuits and increase the energy efficiency of the system.With the software SimulationX,a hydraulic pump simulation model is set up,which examines the movement characteristics of an individual piston and the compressibility of oil,as well as the flow distribution area as it changes with the rotation angle.The pump structure parameters,especially the size of the unloading groove of the valve plate,are determined through digital simulation.All of the components of the series arranged three distribution-window axial piston pump are designed,based on the simulation analysis of the flow pulse characteristics of the pump,and then the prototype pump is made.The basic characteristics,such as the pressure,flow and noise of the pumps under different rotation speeds,are measured on the test bench.The test results verify the correctness of the principle.The proposed research lays a theoretical foundation for the further development of a new pump-controlled cylinder system.