Numerical Modeling and Analysis of Flexure-Pivot Tilting-Pad Bearing

Abstract

This paper presents a new approach for modeling flexure-pivot journal bearings (FPJB) employing a three-dimensional (3D) elasto-hydro-dynamic (EHD) lubrication model. The finite element (FE) method is adopted for an analysis of the (1) pad-pivot dynamic behavior and the (2) fluid force. The isoviscosity Reynolds equation is utilized to calculate the fluid force acting on a flexure-pivot pad bearing and spinning journal. Computational efficiency is achieved utilizing modal coordinate transformation for the flexible pad-pivot dynamic analysis. Fluid film thickness plays a critical role in the solution of Reynolds equation and is evaluated on a node-by-node basis accounting for the pad and web deflections. The increased fidelity of the novel modeling approach provides rotating machinery designers with a more effective tool to analyze and predict rotor–bearing dynamic behavior.