Abstract
Effects of an automatic ball balancer to a rotor with nonlinear spring characteristics are investigated. Similar to the case of a rotor with linear spring characteristics, the rotor is balanced automatically in the higher speed side and the amplitude becomes zero, however, amplitudes in the lower speed side increase and almost periodic motions appear in the neighborhood of the major 9, critical speed. A subharmonic resonance and a summed-and-differential harmonic resonance are eliminated completely by a ball balancer if the masses of balls are large in comparison with the rotor unbalance.
