Stability Characteristics of Gyroscopes With Hydrodynamic-Grooved Rotor Bearings

Abstract

Stability characteristics of a two-degree-of-freedom gyroscope having hydrodynamic-grooved rotor bearings are presented. The two types of oscillations of rotor are parallel whirling and conical whirling. The former is not so significant because the threshold rotor speed for instability is generally very high, and this result has been obtained in previous theories. The latter, in this case gimbals in motion, is very significant. Self-excited conical whirling which starts at low rotor speed and persists into higher ranges was observed. This instability is predictable from the theory presented. The agreement between theoretical and experimental frequency of self-excited oscillation is very good. For simplification, bearings are considered cylindrical, although the experimental apparatus has conical ones. Lubricant is incompressible.