水力发电机组转子质量偏心的数值校正

Numerical Simulation and Correction of Rotor Mass Eccentricity for Hydro-generator Set

水力机械旋转部件质量偏心引起机组异常振动,工程上一般采用动平衡配重的方法解决质量偏心问题。在考虑支撑效应、陀螺效应和轴承油膜动力作用的基础上,采用有限元建模和数值模拟,分析部件在质量微小偏心作用下的动力学特征,将传统处理工艺与数值方法相结合,提出了解决大型转子制造质量偏心的数值校正方法,即微孔调平法。该方法通过精细数值模拟跟踪轴系的摆度和振动的变化,确定附加配重的大小和最佳位置,并在配重对称位置区域在不影响结构工作和电磁效应的前提下采用微孔工艺减重,消除转子质量偏心。工程实践表明,该方法能很好地解决大型转子制造产生的质量偏心问题,在制造过程中可完全消除制造质量偏心引起的异常振动。

A correction method based on traditional processing techniques and modern advanced numerical simulation is used to correct the rotor eccentric caused by machining error,called the micro hole &level adjustment method.The method can effectively track the vibration and the throw at upper and lower guide bearing.It overcomes the limitation of dynamic balance on engineering which is expensive and needs restrict equipment condition.The supper effect,gyroscopic effect and the role of oil film are used for simulating the dynamic characteristics of rotor eccentric with finite element method(FEM),and the details of dynamic behaviors of the unbalance mass whose magnitude and position are effectively captured.The focus of paper is on the oil-film force and orbit of shaft centerline of guide bearing which is main vibration performance.The comparisons with symmetric rotor and the results show that the method is able to well correct the eccentricity caused by machining error.