Numerical investigation on the static performance of aerostatic journal bearings with different pocket shapes by the finite-element method

In this work, to improve the static behavior of aerostatic journal bearings, we examine the effect of pockets with different shapes, including the square, rectangular 1, rectangular 2, and circular, manufactured on the surface of the aerostatic journal bearing. The effects of the pocket shapes, pocket area S over bar , eccentricity ratio e, orifice diameter d(f), average gas film thickness h(0), and misalignment angles phi(x) and phi(y) on the static performance are investigated using simulations. The Reynolds equation is solved by the finite-element method in this work. Simulations reveal that the pocket area S over bar , eccentricity ratio e, gas film thickness h(0), orifice diameter d(f), and misalignment angles phi(x) and phi(y) have a significant influence on the load force F and the stiffness K. In general, rectangular 2 pocket bearings are found to perform somewhat better than bearings with other pocket shapes, with the pocket depth set to one-half of h(0), when the pocket area S over bar varies from one-twelfth to one. The pocket area S over bar should be set according to the average gas film thickness h(0) and the orifice diameter d(f) to achieve a better static performance for the bearings. For bearings operated with misalignment angles phi(x) and phi(y), different pocket areas S over bar should be set according to the pocket shapes for the optimal design.