Reliability-based Robust Design Of Train Bearing In Axle Box

High speed railway has many obvious advantages, such as high security, high speed, low energy consumption, low environmental pollution, high comfortable etc. it plays an important role in the rapid economic development around the world. The high speed train as the core of high speed railway technologies, comprehensively integrates of mechanical, material, computer and many other modern technologies. Bearing as a key part of high speed train, also plays an very important role. In the train running, bearing inner ring and axle contact with a certain amount of interference, in order to transfer torque. Bearing inner ring rotates with axle, undertaking cyclic loading, at the same time, bearing outer ring and the axle box are fixed, no rotating, and undertaking partial load. Because of bearing involving contact problems, analysis of bearing is more complex. Due to the specific contact form of the bearing, in the high stress area under load, bearing structures are prone to be stress concentration too high, it leads to damage or even crack at the same time. Reliability of bearing directly affects the normal operation of the train, even affects the security of the train. Therefore, researching and analyzing some of the key design parameters on the reliability of bearing, provide systematic theory and methods for the reliability of the key components of train.In this paper, based on a lots absorption of the domestic and foreign research on mechanical strength reliability design and reliability robust design, study on reliability and reliability sensitivity of the structure of the bearing. The contents of the main analysis:First of all, make contact analysis of train bearing and axle, analyze the strength of the bearing inner ring, to ensure that the bearing and axle are in good condition with connection. Secondly, basis on bearing suffered the actual load conditions, combined with nonlinear contact theory, using of finite element method, analyze the stress size and the connection situation in the connection area of roller and inner and outer rings of the bearing structure, get the structural deformation and stress distribution, and determine the risk of stress positions when the bearing undertakes loads, and make the strength analysis for bearing under static load. Thirdly, through iSIGHT experimental design and artificial neural network (BP network), fitting the function of the greatest risk stress and structural parameters, make a reliability design for bearing. Combined with neural network technology and reliability sensitivity method, obtain the sensitivity of bearing structural parameters, get the sensitivity of each parameter on the reliability of bearing structure by comparison. Finally, on the principle of lightweight, make the reliability robust design of the bearing structure, build the objective function of the size of constraint functions on quality and the premise of meeting the reliability of bearing,, make the structure parameter sensitivity lowest, and get the optimized size and reliability, thereby enhancing the robust of the bearing.Through the research of the bearing, summarize a set of reliability robust design for bearing, ensure bearing in a certain reliability normal operation, and make the parameters on the structure reliability lowest, it can not only reduce material consumption in the train repairring, but also reduce the frequency of train crashes, better ensure the safe operation of train. In this paper, the results have been obtained through anlysis can provide an important basis for bearing design, and have important practical value.