Vibration is an undesirable phenomenon; unbalance causes a major portion of mechanical vibration and the influence coefficient method is most commonly employed in rotor field balance. However, the need for trial mass and multiple runs make it expensive. We present a new method for locating the heavy spot of an unbalanced single-plane rotor without stopping the machine in this paper. This method is based on a phase-calibrated balance instrument and a specially placed accelerometer and laser tachometer. While corrective weights are not computed, knowing where the heavy spot is located might save time and money on-site. Experiments show that this technology is applicable to a wide range of industrial single-plane rotors. It can also be used as an introduction to trial mass estimate for influence coefficient approaches.

balancing, single-plane rotor, vibration phase, field rotor balance, trial mass location