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Kingsbury, E.

Publications and source records attributed to Kingsbury, E..

9 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1994

The Preliminary Evaluation of Liquid Lubricants for Space Applications by Vacuum Tribometry

Four different vacuum tribometers for the evaluation of liquid lubricants for space applications are described. These range from simple ball-on-flat sliders with maximum in-situ control and surface characterization to an instrument bearing apparatus having no in-situ characterization. Thus, the former provides an abundance of surface chemical information but is not particularly simulative of most triboelements. On the other hand, the instrument bearing apparatus is completely simulative, but only allows post-mortem surface chemical information. Two other devices, a four-ball apparatus and a ball-on-plate tribometer, provide varying degrees of surface chemical information and tribo-simulation. Examples of data from each device are presented.

Jones, W. R., Jr.↗
NASA NTRS1988

Parched elasto hydrodynamic lubrication film thickness measurement in an instrument ball bearing

Parched Elasto Hydrodynamic Lubricant (PEHL) film thickness in a large instrument ball bearing is measured by electrical capacitance across its ball set. Correlation is shown between changes in film thickness and changes in Basic Speed Ratio (BSR) measured at the same time. BSR is confirmed as a sensitive, non-intrusive measure of transients in film thickness in a real bearing.

Kingsbury, E.↗
NASA NTRS1985

First-order ball-bearing kinematics

Two first-order equations are given connecting geometry and internal motions in an angular-contact ball bearing. Total speed, kinematic equivalence, basic speed ratio, and modal speed ratio are defined and discussed; charts are given for the speed ratios covering all bearings and all rotational modes. Instances where specific first-order assumptions might fail are discussed, and the resulting effects on bearing performance reviewed.

Kingsbury, E.↗
NASA NTRS1984

Pivoting and slip in an angular contact bearing

Pivoting slips are calculated for the ball-race and ball-ball contacts in a retainerless bearing. The calculation is kinematic, ignoring all inertial loadings. Pure spin and uniform precession of the balls are considered. Pivoting slip magnitudes are compared with several other kinds of slip which were previously reported in an R4 size bearing. Previously announced in STAR as N83-26079

Kingsbury, E.↗
NASA NTRS1984

The ball bearing as a rheological test device

An angular-contact ball bearing provides an easily obtainable, precise mechanical system for rheological tests on thin films under high pressure. The test conditions are by definition similar to those found in practice. Accessible independent variables include size, pressure, bulk temperature, roughness, adsorbed surfactant, fluid type, fluid quantity, fluid supply rate, film thickness, entrainment velocity, transit time, and combined strain. Easily measured or inferred variables include slip, changes in film thickness with time (transients), strain rate, lubricant elastic modulus (thin film, high pressure), tractive force, lubricant chemical degradation rate, and lubricant degradation product. Methods for setting and obtaining these quantities in a bearing are discussed, together with experimental limitations on them.

Kingsbury, E.↗
NASA NTRS1983

Pivoting and slip in an angular contact bearing

Pivoting slips are calculated for the ball-race and ball-ball contacts in a retainerless bearing. The calculation is kinematic, ignoring all inertial loadings. Pure spin and uniform precession of the balls are considered. Pivoting slip magnitudes are compared with several other kinds of slip which were previously reported in an R4 size bearing.

Kingsbury, E.↗
NASA NTRS1978

Large bearing operation without retainer

The design and testing of large high-speed ball bearings for space application is described. A well-defined lubrication system to provide oil to both race contacts in zero g allows stable operation without ball retainer.

Kingsbury, E.↗
NASA NTRS1973

Cross flow in a starved EHD contact

It is suggested that fluid film thickness in a starved EHD contact is determined by the rate at which lubricant is forced from the Hertz zone normal to the rolling direction. A simple model allows calculation of this flow rate, together with related quantities of interest to the designer.

Kingsbury, E.↗