Thermohydrodynamic Performance of High-Speed Journal Bearings

Abstract

This paper describes the performance characteristics of two types of journal bearings, tilting-pad and offset halves, operating under high-speed conditions where the journal peripheral speed is in excess of 100 m/s. Experimental investigations into bearing eccentricity, temperatures and dynamic coefficients were carried out with a specially designed test rig. These results are compared with theoretical data which are obtained from thermohydrodynamic lubrication theory. The agreement is satisfactory. However, further improvements are necessary to predict more accurate thermal performance of the unloaded pads.

Recent thermohydrodynamic analyses and designs of thick-film bearings

“…7 shows that, the closer the pivot position is to the trailing edge, the lower the maximum pad surface temperature, which is the same as the results in reference [11]. Makino et al [13] presented experimental results of the THD performance of a six-pad tilting-pad journal bearing and also an offset-halves bearing in a bearing test rig operated up to the high speed of 70 000 r=min. They found that the pad surface temperature stagnated and the discharge oil temperature increased markedly around the shaft speed of 30 000 r=min and concluded that the transition from the laminar to the turbulent flow region had taken place at this speed.…”