The Lifetime Prediction Method Study On Rubber Sealing Material Of The Bearing

With the rapid increment of installed wind-turbine capacity throughout the world, the wind power equipment manufacturing industry is developing rapidly. The bearing, which is the core component of wind power equipment, has restricted the developing of China's wind power equipment manufacturing industry for a long time. Domestic bearings can only support the wind turbines below MW-level, and the bearings supporting the MW-level wind turbines are basically imported. The lag of the research and manufacture of its supporting components is caused by the research lag of the bearing. The lifetime prediction research of sealing materials, which is necessary for the bearing, can rarely be found. The dramatic demanding increment of the wind power equipment and the rise of China's wind power equipment manufacturing industry make the coorelative research more urgent and practical. With the imbursment of National 863 Plans Projects:The research and manufacture of bearing test-bed of MW-level wind turbines, this thesis carries out comprehensive and in-depth research, based on theoretic analysis and experimentation about the lifetime prediction methods of rubber sealing materials, and the main contents and results are described as follows:(1) Summarizing the domestic and overseas research actualities of the lifetime prediction of rubber sealing materials, and carries out the research of rubber sealing material aging mechanism, the main factors affecting rubber aging and the methods analyzing rubber aging.(2) Analyzing and comparing the common lifetime prediction models of rubber sealing materials. The thesis chooses the statistical extrapolation model and the lifetime prediction based on modified Arrhenius equation to process the experimental data. The statistical extrapolation model combines the kinetic equation and statistics, and the model not only avoids the risk of choosing the inappropriate equation, but guarantees the accuracy and reliability of the data processing by introducing the parameter alpha. But the strict requirement of the quantity and quanlity of the experimental data is its disadvantage. The caculation of the lifetime prediction based on modified Arrhenius equation is simple and reliable, but the experiment time is a little long and the model can't extrapolate the explicit relationship between time and the performance parameters at a given temperature. Because of the avoidance of the activation energy changes caused by temperature, this model is more accurate in a wider temperature range.(3) Explorating of computation of the chosen models, and comparing and validating of the lifetime prediction results. For the statistical extrapolation model, the thesis gives the detailed MATLAB computing program and gets the results based on the experiment data from the literature. The thesis uses a new try method of the parameter alpha, and takes the implied data ignored by the literature author into account, and obtains a more exact result. For the lifetime prediction based on modified Arrhenius equation, the thesis gets a quite different result by improving the accuracy of the data, and then analyzes the cause of the obvious different. Besides, the thesis processes the same data by using the two chosen modles, and the results show that if the safety factor of the lifetime prediction model based on modified Arrhenius equation is two, the two results are nearly the same.(4) On the basis of former analysis, the thesis carries out the experimental research of rubber sealing material oven acceleration aging according to the related national standards, taking compression set ratio as the performance parameter. Based on the two chosen models, the thesis computes the two prediction lifetimes of viton and enhanced viton, and they are 4.33 years and 6.43 years.