%0 Journal Article
%T The influence of stick每slip transitions in mixed
%A Dirk J Schipper
%A Mark van Drogen
%A Matthijn B de Rooij
%A Shivam S Alakhramsing
%J Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology
%@ 2041-305X
%D 2019
%R 10.1177/1350650118789515
%X A load-sharing-based mixed lubrication model, applicable to cam每roller contacts, is developed. Roller slippage is taken into account by means of a roller friction model. Roughness effects in the dry asperity contact component of the mixed lubrication model are taken into account by measuring the real surface topography. The proportion of normal and tangential load due to asperity interaction is obtained from a dry contact stick每slip solver. Lubrication conditions in a cam每roller follower unit, as part of the fuel injection equipment in a heavy-duty diesel engine, are analyzed. Main findings are that stick每slip transitions (or variable asperity contact friction coefficient) are of crucial importance in regions of the cam where the acting contact forces are very high. The contact forces are directly related to the sliding velocity/roller slippage at the cam每roller contact and thus also to the static friction mechanism of asperity interactions. Assuming a constant asperity contact friction coefficient (or assuming that gross sliding has already occurred) in highly loaded regions may lead to large overestimation in the minimal required cam每roller contact friction coefficient in order to keep the roller rolling. The importance of including stick每slip transitions into the mixed lubrication model for the cam每roller contact is amplified with decreasing cam rotational velocity
%K Elastohydrodynamic
%K cam每roller
%K stick每slip
%K rolling contact
%K mixed lubrication
%K roller slip
%U https://journals.sagepub.com/doi/full/10.1177/1350650118789515