Geometry Effects in Tilting-Pad Journal Bearings

Abstract

A theoretical study has been undertaken to show the influence of bearing geometry on the steady-state and dynamic behavior of tilling-pad journal bearings. The computer model used takes into account a different viscosity on each pad, turbulence in the oil film and pad inertia. The geometric changes considered include the pad clearance and the bearing clearance, the length/diameter ratio, the number of pads, and the orientation of the bearing with respect to the load direction. The major operating characteristics which have been examined are oil film thickness, pad temperature, power loss, and oil film stiffness and damping. The basic form of bearing against which changes in geometry are compared has 5 centrally pivoted pads with a length/diameter ratio of 0.4. The bearing diameters considered in the theoretical study are 160 mm and 400 mm. Comparisons with experiment are also made for bearings having diameters of 160 mm and 430 mm.