Automatic Balancing of a Rotor-Bearing System: On-line Algebraic Identifier for a Rotordynamic Balancing System

A methodology for simultaneously balancing of several modes of vibration for a rotor bearing system by mean the so-called active balancing disk is presented in this paper. In order to determine the magnitude of the unbalance and its angular position on the rotor, it is proposed an on-line identifier based on algebraic identification. A mathematical model was developed for a multiple degrees-of-freedom rotational system for a beam-type finite element with 4 degrees of freedom per node. This model considers the effect of rotating inertia, gyroscope moments, shearing strains, internal-external damping and the presence of active balancing disks. Likewise, the time scale behavior of the proposed algebraic identifier was assessed and analyzed for an unbalanced mass distribution on different locations along the rotor. For this test, the vibration response was obtained from a multiple degrees-of-freedom rotor dynamic system simulation, with several linear coasting up and down. The results show that it is possible to simultaneously balance up to four vibration modes using two active balancing disks.