A test rig for evaluating tilting-pad journal bearing characteristics

Abstract

Tilting-pad journal bearings (TPJBs), owing to their inherent dynamic stability characteristics, have been widely used to support the rotors of high rotating machinery such as steam and gas turbines. TPJBs offer better stability than fixed geometry bearings due to their lower cross-coupled stiffness coefficients. Because of the merit, a large of theoretical and experimental studies have been executed to reveal important characteristics of the TPJBs such as fluid-film thickness, pad–pivot friction, load capacity, temperature, stiffness and damping coefficients and so on. However, the theoretical evaluation of these coefficients for TPJBs is difficult because of their complex geometry, boundary and thermal conditions and turbulent flow. Therefore it is very essential to design and build a suitable test rig for performing experiments. This paper describes a test rig with unusual configuration compared to test rigs which are available in literature for the experimental characterization of TPJBs. The bearings could be installed in the load-on-pad (LOP) or load-between-pad (LBP) configurations. In particular, Sommerfeld number, steady-state and transient temperatures, pad pressure, dynamic stiffness and damping coefficients in different operation conditions could be estimated.