Discussion: “A Three-Dimensional Analysis of Thermohydrodynamic Performance of Sector-Shaped, Tilting-Pad Thrust Bearings” (Kim, Kyung Woong, Tanaka, Masato, and Hori, Yukio, 1983, ASME J. Lubr. Technol., 105, pp. 406–412)

Abstract

rises gradually from T d ( = r in ), and then steeply near the pad surface.As discussed so far, this 3-D analysis can investigate the bearing performance more extensively and more precisely than is possible with the 2-D analysis, and the results obtained with the former often differ from "those obtained with the latter both qualitatively and quantitatively. From the view point of safe operation of bearings, the 2-D analysis should not be adopted because it tends to underestimate maximum temperature rise and minimum film thickness decrease, even though it has the advantage of greatly shortening the calculation time. ConclusionThe authors have analyzed the thermohydrodynamic performance of sector-shaped thrust pad bearing which can tilt both radially and circumferentially, taking into account the three-dimensional variation of lubricant viscosity and density. The temperature distribution in the pad and film were also investigated. The effect of pivot position, disk speed, minimum film thickness, inlet temperature of lubricant, ambient temperature and heat transfer coefficient were elucidated. The results were considerably different from those obtained when the isoviscous or the two-dimensional THD analysis is used. It was shown that the two-dimensional analysis can not substitute for the three-dimensioal analysis. The present theory predicts the bearing performance more accurately and is considered to be useful for design purpose.