DEVELOPMENT OF PRACTICAL COMPUTER-AIDED DESIGN TOOL FOR JOURNAL BEARINGS BASED ON ELASTO-THERMOHYDRODYNAMIC LUBRICATION THEORY AND ITS PROOF TEST

本研究将数学规划的最佳化概念与流体动力润滑理论相结合，发展出一套可降低设计成本的滑动轴承计算机辅助设计工具。规范的可取性由一个函数（目标函数）表示。本文的主要研究成果有：（1）以可倾瓦滑动轴承为例，研究了可倾瓦滑动轴承的设计问题，列出了10个特殊设计变量。(2)研究了轴承特性随设计变量变化的规律，结果表明，梯度投影法和直接搜索法相结合是最合适的。(3)灵敏度分析的结果表明，两个设计变量对轴承特性的影响很小，可以视为常数。(4)综合这些结果，开发了一个基于热流体动力润滑理论的滑动轴承计算机辅助设计工具。(5)在此基础上增加了可倾瓦滑动轴承的特性分析等功能，开发了可倾瓦滑动轴承综合设计工具。(6)对该工具进行了实例测试，结果表明，该工具输出的设计指标在可行设计域中是真正的最优。

In this research, a computer-aided design tool for journal bearings which decreases the cost of design was developed.In this tool, the optimization concept of mathematical programming is combined with the hydorodynamic lubrication theory. The desirability of specification is represented by a function (objective function). The optimal specification is determined automatically by seeking the design variable which minimize the objective function.Main achievements of this research are :(1) As an example, design of tilting pad journal bearings was studied and 10 peculiar design variables were listed.(2) As the result of studying bearing characteristics' behavior against the change of design variables, combination of gradient projection method and direct search method proved to be the most suitable.(3) As the result of sensitivity analysis, it was found that 2 design variables have so little effect for bearing characteristics that they can be treated as constants.(4) Putting together these results, a computer-aided design tool for journal bearings based on thermohydorodynamic lubrication theory was developed.(5) Adding some other functions (for example characteristics analysis function) to the tool above, a synthesized design tool for tilting pad journal bearings was developed.(6) A practical test example of this tool was performed and it was certified that its output design specification was truely optimum in the feasible design region.