Optimization Of Return Mechanism Of Through-shaft Axial Piston Pump

Axial piston pumps have the unique advantages of compact structure,high power density,and long life.They have been widely used in the field of high pressure fluid power.When sucking oil,the through-shaft plunger pump needs a return mechanism to drive the plunger pair to maintain a proper gap with the swash plate.Due to insufficient suction pressure,alternating characteristics of required driving force,etc.,the return mechanism is often damaged,which in turn causes the plunger pump and even the hydraulic system to fail.This paper takes the through-shaft axial piston pump as the research object,and takes the reliability of the return mechanism as the research target.Starting from the kinematics and dynamics analysis,and using a variety of computer-aided analysis methods,the characteristics of the return mechanism are studied.Find out the relevant factors that affect reliability,and carry out structural optimization design based on this,and draw relevant conclusions.The research in this thesis is closely integrated with the application of engineering production,and the relevant research results have certain engineering theoretical application value for the design and production of plunger.The return mechanism of the through-shaft axial plunger pump is composed of a return disk,a ball hinge and a central spring.Taking the return mechanism of the axial plunger pump as the main line,analysis is carried out around the required extension force of the plunger in the oil suction area,the relative movement trajectory of the return disc and the ball hinge,and the pretension force of the central spring.The kinematics and dynamics analysis of the plunger slide shoe assembly is performed to further derive the plunger's extension force in the oil suction area.The master-slave coordinate system of the two is established through the assembly relationship between the return disk and the ball hinge.The relative motion trajectory equation of the two is deduced by using the coordinate conversion relationship to find out the factors affecting the motion trajectory.When the pretension force of the center spring meets the design requirements at the same time,the center spring force is calculated according to the actual parameters.Based on the dynamic analysis function of the ADAMS software,the relationship between the rotation speed of the return disk and the ball joint is analyzed,and it is concluded that there is a certain speed difference between the return disk and the ball joint.Then,the influence of the spindle speed on the contact force between the return disc and the shoe is analyzed based on the theory and ADAMS.Data channels of ANSYS Workbench and ADAMS were established,and transient dynamics analysis was performed using ANSYS Workbench.The effects of spindle speed,swash plate inclination and center taper of return disk on stress of return disk were analyzed.Theoretical analysis When the contact line between the return disk and the ball hinge is near the middle position of the conical surface,the force between them is small.Through ANSYS Workbench,the stress of the return disk under different tapers was analyzed,and the stress value of the return disk in the middle position and the initial position was compared to achieve the purpose of optimization.Fatigue fool was used to analyze the fatigue life and fatigue damage of the return disk before and after optimization,and the results before and after the optimization were compared to prove the effectiveness and correctness of the optimization method.