Accession Number : ADA133127

Title :   Interactive Mechanisms of Sliding-Surface Bearings.

Descriptive Note : Research and development rept.,


Personal Author(s) : Daugherty,Thomas L ; Pan,Coda H T

PDF Url : ADA133127

Report Date : Aug 1983

Pagination or Media Count : 140

Abstract : This report adapts the theory of hydrodynamic lubrication to include surface roughness effects and asperity interactions. This theory becomes a means of studying the behavior of sliding-surface bearings in transition from hydrodynamic into mixed lubrication. A model problem, in the form of a crowned tilt-pad bearing with longitudinal roughness, was solved. In treating the model problem, end-leakage was neglected and a constant lubricant viscosity was assumed. Use of numerical computational methods could readily remove these restrictions. In real operating environments of ship components and shipboard machinery, the lubrication process is made more complex by thermoelastohydrodynamic effects and the likely occurrence of film striation. Because these complicated phenomena are only qualitatively understood, no adequate or comprehensive method exists for designing critical machine components such as face seals, elastomeric sterntube bearings, rudder stock, diving plane bearings, and main shaft thrust bearings. This report is part of a comprehensive plan to develop a better understanding of the interactive wear mechanisms of sliding surfaces. The theoretical basis is the application of Reynold's equation to the mixed lubrication regime. A closed-form solution of Reynold's equation applied to a crowned tilt-pad thrust bearing in transition from the hydrodynamic to the mixed lubrication region is presented to demonstrate some of the principles of this approach. The concepts developed are applicable to a wide variety of bearings and seals.

Descriptors :   *Bearings, *Lubrication, Mixing, Sliding, Surface roughness, Wear, Interactions, Thermomechanics, Friction, Computerized simulation, Hydrodynamics, Cavitation, Lubricating films, Striations, Transitions, Elastomers, Stern tubes(Propulsion), Seals(Stoppers), Thrust bearings, Tilt, Shipboard, Theory, Tribology

Subject Categories : Lubricants and Hydraulic Fluids
      Machinery and Tools

Distribution Statement : APPROVED FOR PUBLIC RELEASE