考虑制造误差的滑动轴承转子系统非线性动力学分析

项目名称： 考虑制造误差的滑动轴承转子系统非线性动力学分析

项目编号： No.50865001

项目类型： 地区科学基金项目

立项/批准年度： 2009

项目学科： 数理科学和化学

项目作者： 徐武彬

作者单位： 广西科技大学

项目金额： 25万元

中文摘要： 滑动轴承转子广泛用于大型高速重载的旋转机械，但轴承转子系统也会出现失稳故障，并会导致系统损坏。从制造的角度来看，轴承转子系统的制造误差是不可避免的，这些误差包括其尺寸偏差和形状误差。虽然轴承转子系统制造误差的绝对尺寸很小，但是与轴承径向间隙相比，却足够大并对系统的运行性能产生显著影响。通过分析滑动轴承转子系统制造公差对其动力学特性的影响，工程技术人员可以在设计阶段合理地选择公差，或者确保存在一定量制造误差的系统的运行性能更趋近与理论上的预测值。本项目系统地研究了考虑制造误差时系统非线性动力学分析、建模和计算方法，引入制造领域的公差与极限的概念，提出了一系列新的无量纲参数来表征系统制造误差对滑动轴承转子系统动力学特性的影响。研究表明：在进行系统设计时，应尽量使系统的Sm在0.15到0.4之间，在此区间系统的制造误差对系统稳定性的影响几乎可以忽略不计；尽管转子的圆度误差可以提高系统的稳定性，但系统的无量纲圆度误差er应小于0.2，当er在0.2-0.4之间时，虽然可以提高系统的稳定性，但系统的高频次振动会加剧；当er>0.4时，轴承转子系统由于剧烈的振动几乎无法运行，因而应避免。

中文关键词： 滑动轴承转子系统;制造误差;动力学分析;Taguchi理论。

英文摘要： Hydrodynamic journal bearings are widely used to provide supports for very large, high speed, and heavily loaded rotating machinery, however, the operation of the journal bearing system is not always stable, which may result in the destruction of the machine. From a manufacturing viewpoint, the manufacturing tolerances of a journal bearing system are inevitable. These tolerances may include dimensional and geometric deviations. Although the absolute size of manufacturing tolerances of a journal bearing system is very small, when compared with the bearing clearance it is large enough to generate remarkable effects on system operating performance. To examine and understand the effect of manufacturing tolerances on dynamic characteristics of a hydrodynamic journal bearing system can help engineers to confidently choose reasonable tolerances at design stage or to enable the system with certain manufacturing tolerances to operate closer to the theoretical predictions. Therefore this project aims to present a theoretical solution to the system stability analysis based on a non-linear oil film model allowing for the manufacturing tolerances. The concepts of limit, tolerance and nominal dimension are introduced into the system analysis. A new dimensionless modified Sommerfeld number is proposed, several new parameters are identified to express the manufacturing tolerances and the effect of manufacturing tolerances on system stability in a proposed new stability map.This research indicates that the system should be designed to operate at Sm=0.15-0.4, here the effects of manufacturing tolerances on system stability are negligible. Although journal out-of-roundness may increase overall system stability, when dimensionless out-of-roundness is below er=0.2, there is little effect; between 0.2 to 0.4, stability is improved but vibration levels are high. Due to the excessive vibration amplitude, er >0.4 is, at present, inadvisable.

英文关键词： Hydrodynamic journal bearing system; Manufacturing tolerances; Dynamic analysis; Taguchi method.