Accession Number:

AD0657454

Title:

SOME FACTORS AFFECTING THE MOVEMENT OF OIL IN MINIATURE BALL BEARINGS,

Descriptive Note:

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s):

Report Date:

1967-07-12

Pagination or Media Count:

19.0

Abstract:

The transport of oil in films less than one micron thick is controlled largely by surface chemical forces, because the gravitational forces operating on such films are one to three orders of magnitude smaller than the surface forces available. Oils spread largely as a result of capillary forces in scratches or submicroscopic irregularities, and because of surface-tension gradients produced by evaporation of volatile components, by adsorption of surface active components, or by differences in surface temperature. Although centrifugal fields intensify inertial effects until they become a significant factor for oil movement in operating bearings, surface chemical forces remain important in gyro bearings which operate on minimum amounts of oil. Hydrodynamic wedge effects join surface chemical forces in the circulation of oil to and from porous separators. Author

Subject Categories:

  • Lubricants and Hydraulic Fluids

Distribution Statement:

APPROVED FOR PUBLIC RELEASE