ABSTRACT
This chapter considers the core of tribology—the traditional hydrodynamic lubrication of a wide spectrum of mechanical devices—and then go on to extend the continuum beyond it to such areas as grease, slurry lubrication, and powder films, just encroaching on the rarest of operations: kinetic flow. To produce hydrodynamic forces, there must be relative motion between the surfaces, which can be either in the longitudinal direction, normal direction, or both. The variety of boundary conditions arising in hydrodynamic lubrication, particularly in journal bearing configurations, result from several possible physical arrangements in the practical usage of bearings, dampers, piston rings and similar devices. A Compliant Surface Foil Bearings (CSFB) operates with a dual film: one hydrodynamic between runner and top foil and an elastic one underneath the top foil. One of the advantages of CSFBs is that they do not allow for the generation of subambient pressures.
