Virtual dynamic balancing method without trial weights for multi-rotor series shafting based on finite element model analysis

Abstract

The traditional influence coefficient dynamic balancing method for multi-rotor series shafting, such as turbine-generator sets, gas turbines, compressor trains, and others, usually needs to startup many times using trial weights along the rotor. Based on finite element model analysis for the multi-rotor series shafting, a virtual dynamic balancing methodology which only needs to collect data of vibration response at operating speed without trial weights is developed in this paper. According to shafting structure and operating parameters, the dynamic finite element model was built by using rotor dynamics theory and finite element simulation technology. The shafting dynamic characteristics and weighted influence coefficient matrix can be gotten by exciting virtual unbalance force on the balance place correspondingly. The effectiveness and flexibility of the proposed method have been illustrated by solving a shafting dynamic balancing example with no trial weights requirements. It is believed that the new methods developed in this work will help in reducing the time and cost of the equipment manufacturer or field dynamic balancing procedures.