Squeeze Film Damper Bearing With Double-Ended Beam Centering Springs: Part I — Design and Analysis

Abstract

Squeeze film damper (SFD) bearings are widely used in industry to enhance rotor dynamic stability in super-critical applications. This study examines an SFD bearing design with double-ended beam centering springs placed external to the squeeze film and in parallel with O-ring seals. The purpose of the new SFD bearing design is to minimize the use of O-rings as a support and centering device, instead relying on compact external springs that can be independently adjusted to ensure centered operation. The new design is applicable to a wide range of bearing sizes and rotor weights with variable spring stiffness, damping value and envelope dimensions. Spring stiffness and stress coefficients were generated for 3.5-inch bearing and SFD assembly from a parametric finite element analysis (FEA). High cycle fatigue of the springs was evaluated using the Soderberg criterion with an additional safety factor. Rotor-dynamic performance of the new design was analyzed using an historical rotor applying both π-film and full-film models. To evaluate the design, the same 3.5 inch SFD bearing presented in this study was manufactured and tested in succeeding work.