Dynamic balancing of a two-plane rotor without phase angle measurement using the amplitude subtraction method

Abstract

Two-plane balancing is required on a rotor where the length is greater than the diameter. Balancing such a rotor is tricky, since the effects of unbalanced forces on both of the planes need to be considered when determining the corrective action. This paper presents a method of dynamic balancing for a two-plane rotor without the need to measure the phase angle. The rotor is balanced by measuring vibration amplitudes at the support bearing of the rotor shaft. A new rotor balancing method of amplitude subtraction is used to calculate the balancing weights and their positions on the rotor. The advantages of this method over the phase angle measurement method are also discussed in the paper.