Chain drive systems are once again becoming prevalent in automotive engines. They contribute a significant amount to the total engine friction, however, and therefore by reducing chain friction overall energy savings will be possible. There is currently not a high level of understanding of how the different chain components contribute to overall chain friction and the exact role the chain tensioners play. Most of the available data is from multi-body dynamics simulations. In these models friction is usually an arbitrary constant. This means that developing advanced lubricants that can help reduce chain friction and establishing exactly how much the lubricant rather than design/operational changes can contribute is difficult.
The aim of this project will be to understand at a fundamental level how the chain drive and lubricant interact and how this affects frictional resistance and component wear. Support will be provided by chain and lubricant manufacturers.
Objectives will include studies of: chain component contact mechanics; lubricant entrainment into chain links, how a film forms and the role of lubricant composition; the effect of the tensioner on friction and the role of the lubricant; the effect of lubricant aging and contamination (e.g. soot) and the effects of using different chain component and tensioner materials and coatings.