Stability Characteristics of Spherical Spiral Groove Bearings : 1st Report, Theoretical Analysis

Abstract

The stability characteristics of spherical spiral groove bearings lubricated with incompressible liquid are investigated theoretically. Solving a differential equation for a bearing which have an infinite number of grooves, we obtain the pressure distribution induced by small vibrations of a rigid rotor about a static equilibrium position. From the pressure distribution we derive a stability criterion for radially unloaded bearings, and clarify the dependence of the stability on bearing parameters and on axial displacements of a rotor. The bearing parameters considered are the spiral groove angle α, the relative groove depth H_g, the groove ratio δ, and rotational speeds of grooved member ω₁ and smoothed member w₂.