Bearings: Technology and needs
A brief status report on bearing technology and present and near-term future problems that warrant research support is presented. For rolling element bearings a material with improved fracture toughness, life data in the low Lambda region, a comprehensive failure theory verified by life data and incorporated into dynamic analyses, and an improved corrosion resistant alloy are perceived as important needs. For hydrodynamic bearings better definition of cavitation boundaries and pressure distributions for squeeze film dampers, and geometry optimization for minimum power loss in turbulent film bearings are needed. For gas film bearings, foil bearing geometries that form more nearly optimum film shapes for maximum load capacity, and more effective surface protective coatings for high temperature operation are needed.
Lubricant Films in Rolling Contact of Rough Surfaces
An experimental and mathematical study of elastohydrodynamic film formation is described for a rolling four-ball configuration utilizing steel bearing balls. Wear rates are determined in the microgram range, using a radiotracer tagged ball. Existence and interruptions of elastohydrodynamic films are observed by measurement of electrical conductivity through the Hertzian contact. Surface microgeometry of the rolling tracks on the balls is statistically analyzed by processing electrical analogs of surface profiles through on-line computing equipment. Defining electrical contacts as asperity approaches through a separating film, the average duration and frequency of such approaches is computed from surface microgeometry statistics. A comparison of computed and observed values of contact conductivity parameters shows good order of magnitude agreement and yields estimates of average film thickness as a function of speed and load which agree, satisfactorily with the order of film thickness predicted by elastohy...
Metallurgical Process Engineering
The "material of choice" - steel.- Uprising of China's steel industry.- Process manufacturing industry and process engineering.- Engineering science in steel manufacturing process.- Analysis and integration of metallurgical manufacturing process.- Multi-dimensional mass flow control for metallurgical manufacturing process.- Time factors in steel manufacturing process.-Operating dynamics in the production process of steel plant.- Structure and mode of steel plant.- Steel plant and environment.