Reliability Design And Failure Analysis Of Axle Gearbox Of XG45-9/540 Locomotive

This paper describes the emergence and development of the reliability discipline, analyzes the development status and trends of reducer.The analysis show that the theory and practice of the reliability have been in-depth studied increasinglyin the domestic machinery industry at present. Facts have proved that,Whether we have the overall reliability design or not, as well as its success or failure, is the key factors to determine the success or failure of mechanical systems. either from saving manpower and material resources, reducing costs or from accelerating trial progress,ensuring product quality and reliability, these have special significance.With the rapid development of machinery industry, a variety of mechanical design software have come out. The users pursuit high-quality ,low-cost and short time of delivery.At the same time, they will reduce the products replacement cycle. So the traditional design pattern has been gradually replaced by virtual design technology. With the virtual assembly designers check size of parts and components and assemblability, modify the error in time. With designers carry out virtual experiment which obviates more physical tests. In this way, time and costs can be saved. In this paper, with SolidWorks as the virtual design platform, three-dimensional solid model of XG45-9/540 locomotive axle gearbox is established, and useing virtual assembly and dynamic simulation capabilities of the SolidWorks, the visual analysis of the box is realized.Based on the established visual box model, the reliability analysis has been done the systematic analysis processes, components and risk elements of system have been determined. So as to arrive the structure of reliability is of Boolean series, and simplify non-risk elements of the system, to make calculation of reliability analysis easier.Through the analysis of reliability, the calculated reliability of XG45-9/540 locomotive axle gearbox is not high, then reliability design is carried on to enhance its reliability. Usually in the reliability design of mechanical product, to improve its reliability and achieve the optimum in construction and performance, the concepts of mechanical optimize design is needed throughout the process of the reliability design. The reliability optimization design of XG45-9/540 locomotive axle gearbox is to meet the conditions of the gear strength, reliability and other performance specifications, and make the reducer smallest and lightest.According to the design ideas mentioned above,the mathematical models of reliability optimization design are established.The optimization toolbox of MATLAB is used to solve practical problems of engineering, and calculate the mathematical models. the calculated results show that the reliability of the reducer is 99% in the specified time,the volume of reducer reduced 6.3%, which means that reducer's structure is more compact, easy to assembly, and full of the benefits of reliability optimization design.Because the mechanical systems work in the long time, affected by the environment and applied load, occurrence of failure is unavoidable. In view of this situation, the failure analysis on fracture of XG45-9/540 locomotive axle gearbox bracket is made in this paper. the cause of the failure is described, and the objective with stress analysis as main line is identified to make finite element analysis. By the interface of SolidWorks with ANSYS, the complete model is input into ANSYS, with ANSYS for stress analysis of gearbox bracket, the figure of stress distribution and the path curves are obtained. At the same time, COSMOSXpress in SolidWorks is used to analyse the stress of bracket again. The results show that the concentration location of stress in COSMOSXpress is as the same as in ANSYS, which are compared with fracture location of bracket,and are in accordance with realistic fracture conditions. The bracket fracture may be due to impulsive overload.In this paper ,modeling, analysis, design and optimization are integrated together and researched, which has great significance for design efficiency and level of XG45-9/540 locomotive axle gear box.