Studying Of The Piston Of The Axial-Piston Variable Displacement Hydraulic Pump Based On The Modern Design Method

With the increasing for the function requirement of mechanical product, the period that the product is regenerated becomes more and more short , but the traditional product design and analysis method can't suit the requirement needed by modern society. Because of the powerful and low cost computer is popularizing, the modern design technology which takes the computer application as the foundation emerges. Nowadays, the constant-power-control variable displacement axial-piston hydraulic pump have be used in most of construction machine and equipment for their power equipment.The quality of the whole machine is determined by the quality of the piston pump. Because the piston is the most important part of the piston pump, it is becoming necessary to study of the piston with modern design method. Modern design method can greatly decrease the period of the design and speed up the development course of new product. According to the characteristics of the piston pump when it works with the diesel engine , the different outer load leads to different rotational speed and mechanics characteristics of the piston . In order to learn the property of the movement and mechanics of the piston but not experimentalize, SIMULINK which is the simulation toolbox of MATLAB ( the most popular large-scale mathematic software) is carried out to simulate the process of the movement and the receiving force of the piston . In order to get the entire stress distribution of the piston, Solidworks (simple operation and three dimensions graphics software) and ANSYS ( a large-scale finite element analysis software )are used with synthetical method to analyse the piston.This thesis has carried on research in the following aspect and gained some achievement. Firstly , synthetically studying of the characteristic of the modern design and the piston, the route of modern design technology route for piston pump is put forward. Secondly, studying of the property of the pump when it works with diesel engine , the several kinds of typical work condition are gained . Based on these typical work conditions , all the kinematic formula for the piston in the axial-piston hydraulic pump are deduced , the movement of the piston is simulated . Thirdly, based on the force acted on the piston, the mechanics formulations are deduced. Combining with the result of the kinematic analysis, the dangerous status which the piston is received force for every kind of work conditions are simulated, and then the most dangerous status is gained. Finally, based on the most dangerous status which is received by analyzing the forces acted on the piston , the finite element analysis is carried out for the piston with ANSYS . After the analysis, the stress distribution of the piston and the seat of thebiggest stress are gained, and the reliability of piston is verified .All have done in this thesis provide the theory basis for improving the design of the piston of the constant-power-control variable displacement axial-piston pump.