MECHANICAL AND THERMAL DEFORMATION ANALYSIS OF A LARGE POLYMER LINED TILTING PAD JOURNAL BEARING

An increase of specific load in large tilting pad journal bearings (TPJB) leads to major mechanically and thermally induced deformation of the pads and limits the load carrying capacity. In this paper, we present a theoretical approach to determine deformation of a TPJB with PEEK (Polyetheretherketone) polymer lined pads by means of a thermo-elasto-hydrodynamic model. The objective of this investigation is a quantitative analysis of the deformation characteristics of a five-pad TPJB with a nominal diameter of 500mm. Mechanical and thermal deformations are simulated for both the steel backing and the polymer lining. The deformation characteristics calculated with the numerical model are compared to simulation results of an experimentally validated model with a white-metal lining. The results indicate an improvement in bearing characteristics with the PEEK lining, as maximum pressure decreases and minimum film thickness increases. Due to the insulating properties of the PEEK layer, thermally induced pad deformation is reduced significantly.