Elastohydrodynamic Lubrication of Involute Gears

Abstract

A criterion is suggested for the application of the steady state elastohydrodynamic theories to the analysis of involute gear contacts. The criterion is based on a comparison of two physical time scales characterizing the system. It is found that for heavily loaded gears the unsteadiness effect may be important. A mean-viscosity method using a composite pressure-viscosity model for the lubricant is introduced for contact zone temperature calculation. An example of involute gears is given for the computation of elastohydrodynamic contact variables based on quasi-steady state assumption. It is found that the surface temperature rise in the tooth tip contact is much higher than that in the pitch line contact.