潤滑油の境界摩擦とその測定法に関する二三の覚え書

概要

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We often obtain for one oil different values of boundary friction when different apparata are used. This discrepancy is usually ascribed to the "complexity" of measuring conditions. The most important factor in it, however, is the difference of rubbing velocities. Experiments on boundary friction are carried out with two oiliness testers of widely different principles : the one is that of pendulum type, the maximum rubbing velocity of which is 0.6 mm/sec, and the other the four ball tester, of which the rubbing velocity is controlled between 0.58 and 230mm/sec. Despite the widely different conditions of contact pressures, the boundary frictions measured by the two testers are found to coincide well when the same rubbing velocity is adopted. From these experiments, moreover, it is found that the rate of decrease of boundary friction with the increase of rubbing velocity in the neighbourhood of velocity zero is larger for oils of low oiliness than for those of high oiliness. Boundary frictions with parallel flat surfaces are also measured, and the formation of viscous film is found to be unavoidable between flat surfaces even finished perfectly owing to waviness of the surfaces, being the most difficult to be removed from the surface. (Received June 9, 1952)
宇宙航空研究開発機構の論文
1952-08-20