The elasto-hydrodynamic lubrication of rollers

Abstract

Gears rollers frequently operate at loads sufficient to deform them appreciably and to enhance the viscosity of the lubricating oil in the region of closest contact. No rigorous theory of this state of lubrication has been available hitherto. In this paper an iterative procedure is developed and has been followed with a digital computer. The calculations yield the oil film thickness, the pressure distribution and the shape of the deformed system. Solutions are given showing the effect of load and speed; the influence of the pressure coefficient of viscosity of the oil, and of the elasticity of the rollers is also shown. The main feature of the results is the prediction of peaks of pressure on the outlet side of the system, the height of the peaks depending greatly upon the foregoing variables. The theory is compared with the available experimental evidence and though it is a clear improvement upon earlier theories, significant differences between theory and experiment yet remain. The origin of these differences is discussed and it is concluded that there is greater need at the present time for fuller experimental evidence than for further elaborations in the theory.