弯扭耦合的旋转机械轴系弯振特性的研究

Investigation of the Bending Vibration Features of the Rotary Shaft Based on the Flexural Vibration Coupled with the Torsion

随着旋转机械在役运行时间的增加,转子部分多数会有质量偏心现象出现。这使得转子轴系的扭转振动与弯曲振动的耦合作用明显增强。在已有耦合振动方程基础上,采用有限差分、Newmark积分法求得动力响应,以300 MW汽轮发电机组为研究对象,将其模化为多支承分布质量模型,采用FFT、STFT和wavelet多种方法分析它在简谐衰减、非同期并列两种典型工况激励下以及不同偏心函数、弯扭下的弯振特性。分析结果为研究旋转机械复杂转子系统耦合振动中弯振特性的定量、定性分析提供了依据。

With increasing of the runtime of rotary machine, rotor parts have inevitable mass eccentricity, which obviously strengthens the coupling function of torsional and bending vibration of the shaft system. On the basis of the established coupling formula, dynamic response of the shaft was investigated using the Difference method and Newmark integral one. And then using FFT, STFT, wavelet method, the flexural oscillation characteristics of a 300 MW turbo generator, simulated with multi-supporting distributed mass model, were analyzed on the two typical operating conditions of the harmonic attenuation urge and the asynchronous juxtaposition urge with different eccentricity functions and ratio of bending and torsion. The results can be reference to the qualitative analysis and quantitative study to the bending character of a complex shaft system coupling vibration of the rotary machine.