The Effect of Area Contact on the Static Performance of Multileaf Foil Bearings

Abstract

For multileaf foil bearings, the interactions between adjacent foils, foils, and gas film are key to predicting the bearing performance. However, most of the analytical models were based on line contact rather than area contact between adjacent foils and the latter may occur and play an important role in load capacity. In this study, the curved beam model is adopted to build an elastohydrodynamic model considering the area contact between adjacent foils, which is solved iteratively coupling the Reynolds equation with the finite element method. An algorithm is developed to judge and determine the contact condition of adjacent foils. The simulation results show that the area contact between adjacent foils does occur and the contact area expands with increasing eccentricity ratios and rotational speeds, which make the film thickness distribution smooth and are beneficial to the increase in load capacity. The area contact occurs near the trailing end of the foils first and then gradually expands. The later formed contact area bears greater load capacity compared to the early formed contact area, and the load capacity is mainly provided by the gas film on the foils with greater area contact.

KEY WORDS:

• Foil Bearing
• Hydrodynamic Lubrication
• Area Contact
• Bearing Performance