Paper 9: The Role of Lubrication in Gear Design

Abstract

The paper gives an account of the way in which the results of fundamental studies of the lubrication mechanism in gears are now being incorporated in gear design procedures. The background to elastohydrodynamic lubrication is summarized and the importance of film thickness calculation is noted. The role of the lubricant in gear lubrication and its effect upon scuffing and pitting are considered. The importance of a film thickness ratio in determining the resistance to both forms of surface distress is emphasized. An improvement in surface durability is likely to lead to important increases in the ratings of many gear sets. The results of many years of research work on gear lubrication can now be embodied in design procedures for the optimization of resistance to scuffing and pitting, and the designer should be encouraged to treat the lubricant as an engineering material and a component in the gear system.