Influence of Ball Bearing Stiffness on Squeeze Film Behavior Including Fluid Flow Turbulence and Inertia Effects

Abstract

The squeeze film damper is a fluid film bearing device to suppress vibration in high speed rotating machinery. The basic geometry is two concentric cylinders with a lubricating oil filling the annulus between them. The inner cylinder is fixed to a rolling element bearing outer race and usually performs a constant speed circular precession about the outer cylinder axis. The squeeze film bearings have found extensive use as a means of introducing damping into rotor-bearing assemblies and hence reducing vibration amplitudes to acceptable levels. Then a fundamental problem is to determine the squeeze film dynamic coefficients. We present in this study the influence of ball bearing stiffness on the squeeze film bearing. The two elements are first studied separatly and then gathered to obtain a dynamic representation of the assembly constituted of the ball bearing and the squeeze film damper.