Accurate Measurement For The Amplitude And Phase And The Research On Rotor Dynamic Balancing

In this paper, the method to accurately get the amplitude and phase of the vibration signal caused by unbalance is studied, and the influence of shaft surface error on the precision is concerned. Meanwhile, several balancing methods are analyzed. With the aid of Visual C++ and MATLAB, an Objected-Oriented balancing software based on windows is designed. Some experiments have been made.Three methods to accurately get the amplitude and phase of the vibration signal caused by unbalance are studied deeply, and the universal phase difference correction on discrete spectrum is introduced. The paper mainly studies the theories, error analysis and applied condition of the two methods called complete alternation truncated DFT and phase difference correction. Stimulating programs of the two methods have been accomplished with Visual C++.The balancing methods and their implementations of single-plane and double-plane balancing in rigid rotor are studied, as well as the modal balancing method, the influence coefficients balancing method and the mode circular balancing method for flexible rotor, especially the influence coefficients balancing method and the mode circular balancing method. Meanwhile, the influence of shaft surface error on the precision of rotor dynamic balancing is analyzed, and a method is proposed to overcome it.Finally, based on these theories, an Objected-Oriented balancing software is designed with Visual C++, Visual C++ & MATLAB, which includes four modules: single-plane and double-plane balancing method for rigid rotor, the influence coefficients balancing method and the mode circular balancing method for flexible rotor. Experimental results verify the practicability of the software. The User Interface has favorable maneuverability.As a series of experiments on rotor dynamic balancing having been done, the results show that the rates of decline of unbalancing are 80.36% in single-plane balancing method, 72.8% of the first point and 75.59% of the second point in double-plane balancing method for grid rotor. The rates of decline of unbalancing of the two points are 70.56% and 66.61% in the influence coefficients balancing method when the rotation speed is at 2800rmp, as well as 54.2% and 60.2% in the mode circular balancing method for flexible rotor. These experimental results indicate that the four balancing methods have higher balancing precision.