Abstract: Tilting pad bearings are commonly adopted by large turbo-generator units, but unstable forced vibration and oil film whirling often happen to them in practical operation. For solving the unstable vibration of tilting pad bearings, the influences of the preload factor on the oil film stiffness coefficient, damping coefficient and temperature rise are studied with the finite difference method. The study discovers the relationship between the performance of the bearings and the preload factor. With the adjustment of preload factor, the unstable vibration fault of tilting pad bearings is eliminated.

Key words: turbo-generator unit, tilting pad bearing, preload factor, vibration