Effect of loaded-pad thickness on the static behaviors of five-pad hydrodynamic journal bearings

The use of tilting pad journal bearings (TPJBs) has increased in the recent past due to their stabilizing effects on the rotor bearing system. Most of the studies about steady state and dynamic behaviors of TPJBs are usually evaluated by means of thermohydrodynamic models assuming nominal dimensions for the bearing. However, machining errors could lead to actual bearing geometry and dimensions different from the nominal ones. In particular, for TPJB the asymmetry of the bearing geometry leads to unexpected behavior of the bearing. In this paper, effects of non-uniform clearance on TPJBs’ performances such as clearance profile, shaft locus, power loss, pad tilt angle, and pressure distribution are evaluated using an analytical model. The results show that effects of non-uniform clearance on static characteristics of TPJBs are considerable when evaluating the efficiency of the bearing in particular and system in general.