A New Mathematical Analysis of Two–Plane Balancing for Long Rotors without Phase Data

Abstract

Two–plane balancing procedure is usually adopted to balance long rotors using both vibration amplitude and phase data. This paper presents a new mathematical analysis of two–plane balancing method for long rotors using vibration amplitude data only. This method requires eight test runs with two balancing planes nearby the bearings. The tests are performed by connecting a known trial mass to eight different positions individually; four at each plane, where each position being advanced ( ) from its previous. In this study, a comparison has been performed between the new mathematical analysis and another traditional analysis presented in a previous study. Firstly, two computer programs based on both analyses have been written using  Language in order to compute the magnitudes and locations of the required balancing masses. Secondly, the comparison has been made using balancing simulator for rigid rotors where different sizes of rotors at different rotation speeds have been tested. This study showed that the two–plane balancing method based on the new analysis was always capable of performing a very high grades of balance while traditional analysis showed an observed restriction in achieving a good quality of balance for the rotors been tested.