Design Of Three-directional Fatigue Tester For Traction Link Bush

The traction link bush is important connector of rail locomotive,whose load subjected is multi-directional fatigue load.In order to ensure the safe operation of the locomotive,traction link bush should take fatigue test in manufacturing process after considering the working condition.Due to the existing traction rod fatigue tester of the cooperation unit has limited kind of fatigue tests including Unidirectional fatigue test and bidirectional fatigue test,which have big difference than actual loading situation of the traction link bush.The fatigue test data of it can not actual reflect real fatigue property of traction link bush.This topic were to design a triaxial fatigue testing machine whose feature of the traction bush include deflection loading,torsion loading and radial loading.The main research content of this topic is as follow:1.According to the actual work situation of the traction bush,this topic analyzed fatigue failure phenomena and characteristics of the traction bush.combining with the existing infrastructure conditions of the entrusted entity and according to the design requirement,a design scheme for the three-directional motion of two hydraulic cylinders simultaneously implementing deflection loading,torsional loading and radial loading was proposed.2.Explained the working principle of the traction bush testing machine,and based on the multi-directional fatigue test requirement of the entrusted unit,a detailed design calculation was made for the deflection loading mechanism,torsional loading mechanism and radial loading mechanism of the traction bush testing machine;Through analysis and calculation,completed the selection of related parts and components.3.Based on the design of the institution model,this topic derived the conversion relationship between cylinder stroke and output load,and designed and calculated the stepless transformation between the torsional load and the deflection load;In this paper,through the method of analysis and comparison,the strain gauge method was selected to measure the torsional load and deflection load in real time.Using NX UG8.0 to completed the three-dimensional modeling and kinematics simulation of the traction bush three-direction fatigue testing machine,verifying the accuracy of the angle matching design calculation.4.Use ANSYS workbench software to perform the finite element analysis on the key components of the traction bush three-direction fatigue tester,check whether its strength meets the requirements,and based on the static analysis results,using Ncode Designlife software to carry out the key components of the fatigue tester.Fatigue life simulation analysis verifies the rationality of the design.5.A three-directional fatigue tester for tow-ball joints based on two cylinder drives was developed.A fatigue test was performed on a certain type of traction rod ball joint.The static stiffness change rate before and after of the torsion ball joint fatigue test was measured,and the fatigue performance data of this type of the traction bush was obtained.The tests have shown that the traction bush fatigue test machine developed satisfies the technical requirements of the commissioning unit.