Influence of pivot design on nonlinear dynamic analysis of vertical and horizontal rotors in tilting pad journal bearings

Publication date: Available online 6 July 2019Source: Tribology InternationalAuthor(s): Zhaoyang Shi, Yingze Jin, Xiaoyang YuanAbstractThe influence of pivot design on nonlinear dynamic characteristics is investigated for vertical and horizontal rotors. Rocker-back pivot and ball-socket pivot designs are studied. A mathematical model is presented considering Hertzian contact theory for pivot stiffness calculation. Differential diameter effects are also discussed. The pivot design effects on the journal orbits, fluid film thickness and pressure are provided and analyzed. It is shown that pivot design can significantly alter the orbit, render an angular shift, and result in a decrease of film thickness and an increase of film pressure. Further, pivot design effects are sensitive to pivot load from both large unbalance and static load. When differential diameter is below 100 μm, its corresponding effects on journal orbits are significant.
Source: Tribology International - Category: Materials Science Source Type: research