Theoretical investigation of the effect of offset loads on the static characteristics of a multi-pad adjustable bearing geometry

An adjustable or controllable form of bearing geometry embodying four multiple pads circumferentially positioned around the journal is presented in this study. The proposed pad geometry has a novel feature to undergo radial and tilt adjustments in both inward and outward directions from the reference position. The adjustability principle of bearing pads helps to attain a controlled bearing operation in the clearance spaces. This paper investigates the effect of offset loads on the steady-state characteristics of a four-pad adjustable bearing. A modified film thickness equation is applied to take account of the radial and tilt pad adjustments in the theoretical analysis. Variation in fluid film pressures and static characteristics is analysed for different pad adjustment conditions and offset load positions. From the comparative study, superior static performance is obtained for bearing operated with an offset load of χ/α = 0.45 and negative pad adjustment configurations than compared with central load condition.