A GLOBAL APPROACH OF THERMAL EFFECTS INCLUDING PAD DEFORMATIONS IN TILTING-PAD JOURNAL BEARINGS SUBMITTED TO UNBALANCE LOAD

The purpose of this paper is to study the response of a tilting-pad jo urnal bearing submitted to an unbalance load A pseudo-time transient a nalysis has been developed taking into account the effective viscosity of the lubricant the thermal expansion of bearing elements, and the e lastic pad deformations. At each time interval, and for each pad, an e ffective temperature of the film is deduced from art energy balance. F irst, a comparison between theoretical results and experimental data i s presented for a four-shoe tilting-pad journal bearing subjected to a static fond. Second, the influence of the thermal and pad flexibility effects on the journal center orbit, on the minimum film thickness an d on the maximum pressure is studied for various unbalance lends. Both the viscosity variation and the operating clearances due to elastic a nd thermal deformations of the bearing elements have a great influence on the behavior of the bearing.