The restrictive effects of capillary compensation on the stability of the Jeffcott rotor-hybrid bearing system

The influence of restriction parameters, recess depth and land-width ratios on the load capacity and stability of a Jeffcott rotor supported by single-row, six-recessed hybrid bearings with capillary compensation is studied. The finite difference method is used to solve Reynolds equation, whilst the determination of stability threshold uses the Routh-Hurwitz method. The load capacity, stability threshold, and the critical whirl ratio, versus the changing restriction parameters, are each simulated for both shallow-recessed and the deep-recessed bearings with various land-width ratios. Simulated results indicate that small land sizes are necessary for shallow-recessed bearings in order to yield good performance, and these bearings are superior to deep-recessed bearings. Furthermore, both load capacity and stability threshold become correspondingly greater with a decrease in the restriction parameters. Nevertheless, the appropriate design of both restrictor and land size in deep-recessed bearings might well induce both load capacity and stability threshold greater than in shallow-recessed bearings.