Numerical study on foil journal bearings with protuberant foil structure

A numerical model coupling the hydrodynamic pressure of lubricant film with the deformation of foil structure was developed for a type of foil journal bearing with protuberant foil structure. An isothermal and isoviscous lubricant was used in the fluid model, and a perturbation method was applied to linearize the Reynolds equation. The top foil was modeled as a strip of rectangular thin plate supported at a rigid point. The distributions of film pressure, film thickness, and foil deformation were solved by the finite element method (FEM). The effects of eccentricity ratio, bearing number, and number of protuberances on the characteristics of bearings were analyzed.

► Numerical simulation of a new type foil journal bearing with protuberant structure.
► Distributions of film pressure, film thickness, and deformation of the foil structure are obtained.
► Bearing characteristics are significantly affected by the increase of bearing number, particularly with respect to small bearing number.
► The top foil with appropriate lines of protuberant support may warp upwards at the bearing sides because of the bending stress.