Analysis and Experiments on Multi-Plane Balancing of a Flexible Rotor

Abstract

The accuracy of the conventional method of field balancing is investigated. A test rotor is provided with a known set of unbalance weights and is subsequently field-balanced by the trial-weight method, using the same planes in the rotor as those in which the unbalance weights are inserted. Vibration measurements are taken at several locations and speeds, and the results are used to calculate the required correction weights by means of a computer program, based on a least-squares minimizing procedure. A direct comparison between inserted and calculated weights gives a check on the method. Tests are conducted for balancing in two and three planes, and several types of analyzing instrumentation are employed for comparison. The accuracy of the measurements is also investigated.