A study of asperity interactions in ehl line contacts

A computer program capable of simulating thermal micro-EHL is used to study asperity interactions in EHL line contacts. The study progresses from a pair of two-dimensional asperity ridges that interact at various locations within an EHL conjunction, to two sinusoidal wavy surfaces, and finally to surfaces with random-like roughness structures. Two values of slide-to-roll ratio, 0.1 and 0.5, are used representing low sliding and high sliding conditions typically found in gear teeth contacts. Results obtained suggest that in EHL line contacts with transversely oriented surface roughness, the asperities collide more frequently with the lower slide-to-roll ratio. The results further suggest that the collisions occur more easily in the central-outlet region of the contact when the slide-to-roll ratio is low, and they occur more easily in the inlet-central region of the contact when the slide-to-roll ratio is high. A more complete analysis needs to be carried out when the structures of surface roughness are more realistically modeled. Furthermore, to simulate the interactions of rough surfaces under more practical EHL conditions, a more accurate computational model needs to be devised for asperity solid-to-solid contact, and the effects of three-dimensional roughness should be included.