Tribo-Optimum Design of Fluid Bearings Considering Vibration and Its Experimental Verification

流体动压径向轴承被广泛应用于支撑涡轮机、压缩机和泵等高速旋转机械。尤其是在各种类型的流体动压滑动轴承中，椭圆滑动轴承因其结构简单、制造成本相对较低、承载能力和稳定性高而具有优异的耐久性而广受欢迎。因此，改善椭圆轴承在高速运行条件下的性能特性是提高旋转机械质量的重要工程问题。由于高速椭圆径向轴承的性能特性受多个轴承参数的制约，轴承设计者通常采用传统的试错法，利用大量的设计图表来选择设计变量。在本研究工作中，通过优化DES…来改善高速流体动压径向轴承的性能特性并将计算结果与实验结果进行了比较。主要结论如下：(1)将直接搜索法和二次规划法相结合，提出了改善高速动压滑动轴承静动态特性的通用优化设计方法。(2)将优化设计方法应用于椭圆滑动轴承的优化设计。在轴颈转速的高速范围内，有效地确定了油膜温升、漏油流量和起旋转速的加权和为4个设计变量：垂直和水平间隙、轴承长径比和轴承方位角。(3)将优化后的轴承特性与随机选取的设计变量计算的轴承特性进行了比较，验证了优化设计的有效性。文中提出的优化设计方法可方便地应用于其它类型的高速动压滑动轴承，如三叶轴承、偏心轴承、阶梯可倾瓦轴承等。

Hydrodynamic journal bearings have been widely used to support high-speed rotating machinery such as turbines, compressors and pumps. Especially, among of various types of hydrodynamic journal bearings, elliptical journal bearings are popular because of their simple structure, relatively low manufacturing costs and superior durability due to the high load carrying capacity and stability. Therefore, it is an important engineering problem to improve the performance characteristics of elliptical journal bearings in the high-speed operation conditions for enhancing the quality of rotating machinery. Generally, as the performance characteristics of high-speed elliptical journal bearings are governed by a number of bearing parameters, the bearing designers usually try to select the design variables by the conventional trial and error method using many design charts.In this research work, the improvement of performance characteristics of high-speed hydrodynamic journal bearings by optimum des … More ign was developed and the results were compared with the experimental results. The conclusions are briefly summarized as follows :(1) The general optimum design methodology combining the direct search method and SQP was developed for improving the static and dynamic characteristics of high-speed hydrodynamic journal bearings.(2) The optimum design methodology developed was applied to the elliptical journal bearing design. The four design variables such as vertical and horizontal clearances, bearing length-to-diameter ratio and bearing orientation angle were determined effectively to minimize the weighted sum of oil film temperature rise, leakage oil flow rate and the inversion of whirl onset speed for a high-speed range of journal rotational speed.(3) The optimized bearing characteristics were compared with the characteristics calculated from the random selected design variables, and then the effectiveness of optimum design was confirmed. Moreover, the effectiveness was also confirmed experimentally.The optimum design methodology developed here can be easily applied to other types of high-speed hydrodynamic journal bearings such as three-lobe, offset, stepped tilting pad bearings etc. Less