Showing papers on "Lubrication theory published in 1981"

Performance Characteristics of Noncircular Bearings in Laminar and Turbulent Flow Regimes

Abstract: Using linearized turbulent lubrication theory of Ng and Pan, the modified Reynolds equation has been solved by finite element method using Galerkin's technique. Static and dynamic performance characteristics of the noncircular (two-lobe) bearings have been studied, both for laminar and turbulent flow, in terms of load support, oil flow, fluid film stiffness coefficients, damping coefficients, and critical mass for various Reynolds numbers.

Lubrication in metal cutting and grinding

Abstract: Metal cutting has several unique features that distinguish it from metal forming and from plain sliding. Extensive new surface is generated in immediate contact with the tool, so that contact with any liquid lubricant does not occur until the sliding process has been completed. The sliding speed is usually very high and the time of transit very short, typically 1 ms or less. It is consequently widely believed that boundary friction and lubrication theory is quite inapplicable to metal cutting, and even less so to grinding. Nevertheless, important analogies can he drawn, and lead to useful practical conclusions. A simplified application of the principle of least action provides a useful approximate model of cutting. Direct experiments confirm that the length of contact on the rake face is a dominant factor, and there is strong evidence that this length is itself determined principally by the adhesional conditions at the interfaces. The reduction of rake-face contact by lubricants has been examined...