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

Squeeze film damper (SFD) bearings are widely used in industry to enhance rotor dynamic stability when operating at super-critical speeds. This study examines an SFD bearing design with load cell type centering springs placed external to the squeeze film and in parallel with O-ring seals. The SFD bearing design minimizes the use of O-rings as a support and centering device relying primarily on compact external springs for support that can be independently adjusted to ensure centered operation of the SFD journal. A hydrodynamic tilting pad journal bearing (TPJB) is a part of the design and placed in series with the SFD.

The objective of the SFD is to achieve rotor dynamic stability for rotors that would otherwise not be stable.  Critical performance parameters include overall SFD stiffness and damping for control of the unbalance response and rotor dynamic stability.  The critical design parameters, which influence the performance of the SFD include geometric envelope, length, diameter, clearance, oil feed, and spring design.  Spring design and analysis is a specific focus and includes evaluation of centering capability, spring rate and spring life.

Part one of this two part paper presents the squeeze film damper design parameters as a function of rotor weight, rotor flexibility, and bearing size.  Specific examples are provided in which SFD bearings are designed for application to several historical rotors having stability problem.  Improvements to the predicted stability are presented.

(This paper is the part I of a two parts study. Another abstract for part II is also submitted)