Research On Open Circuit Variable Radial Piston Pump

In recent years,ultra-high pressure,large flow pumps have received widespread attention from the hydraulic industry.In order to achieve ultra-high pressure and large flow,the hydraulic system usually increases the pressure booster to increase the system pressure.Although this method solves the problem of ultra-high pressure to a certain extent,it has problems such as complicated hydraulic system,serious leakage,and high cost.In view of the above problems,based on the principle of open-circuit piston pump,this paper develops a open-circuit variable radial piston pump,and can realize high-pressure and large-flow output through multiple pumps in series.The pump adopts limited-pressure external feedback variable method to achieve continuous control by controlling the eccentricity between stator and rotor of variable radial piston pump.which achieves the effect of continuous adjustment of pump flow and achieves the purpose of energy saving.This paper analyzes the working principle of the limited-pressure external feedback variable mechanism.The basic structure,working principle and structural characteristics of the new variable pump were analyzed.The three-dimensional modeling of the part structure was performed using three-dimensional software Solidworks.According to the movement of the plunger,the kinematics of the new variable pump is analyzed.The expressions of displacement and instantaneous flow rate of the new variable displacement pump are deduced,and the influence of the number of plungers on the flow pulsation is analyzed.The instantaneous flow rate of the variable radial piston pump in series was analyzed.The force acting on the shoe was analyzed and an oil film model was established.The residual pressure force method was used to solve the oil film thickness of the shoe pair.The mechanical properties of the plunger,rotor,stator and other structural parts of the open-circuit variable radial piston pump were analyzed.Ansys simulation software was used to analyze its strength and stiffness.The steady-state characteristics of the new variable radial piston pump are analyzed,and the relational expressions of output flow and working pressure are derived.Design and calculate various parameters of the pressure regulating spring and check the strength of the pressure regulating spring.The dynamic characteristic of the new variable pump is analyzed,the transfer function of the new variable pump is derived,the mathematical model of the dynamic characteristics of the system is established.Simulation is performed using Simulink simulation software and analyze the factors that affect the dynamic response speed of the variable pump system.An experimental platform for the analysis of the steady state characteristics of a new type of variable radial piston pump is built.The feasibility of the variable principle of the new variable radial piston pump and the rationality of the variable mechanism design are verified.