On the Shaft End Torque and the Unstable Vibrations of an Asymmetrical Shaft Carrying an Asymmetrical Rotor

Abstract

In a rotating asymmetrical shaft carrying an asymmetrical rotor, there occur two types of unstable regions. These unstable regions change with the orientation angle ζ between the inequality of shaft stiffness and that of rotor inertia. The conditions under which unstable vibrations occur just as input energy into the rotating shaft system tends to increase the whirling amplitudes of the shaft, can be clearly ascertained. These conditions, which depend on the angle ζ, tend to show a good coincidence with those obtained by an analog computer. Moreover, when asymmetrical shaft stiffness Δ_ij and asymmetrical rotor inertia Δ₀ are chosen suitably, two types of unstable regions are eliminated.