Wear and elastohydrodynamic lubrication studies of cams and followers

The concentrated non-conformal contact between the cam and the follower is one of the most severe working tribological components in the internal combustion engine. Due to the continuous variation of load, speed and geometry, this contact is very difficult to be investigated. This work is mainly devoted to review the wear and elastohydrodynamic film thickness studies related to this important engine mechanism and is divided into two parts. In the first part a review is made of theoretical/numerical studies addressed to predict the film thickness, pressure distribution and their relations with the most common surface failures as pitting and scuffing. The second part is committed to show the experimental efforts that have been carried out to estimate the real film thickness and the force friction in order to improve the durability of mating cam/follower surfaces under elastohydrodynamic lubricating regimen. A new versatile experimental apparatus under development is also presented.