Friction reduction in piston ring cylinder liner contact using textured surfaces

Abstract

The automotive industry is increasingly required to meet tough emission standards such as Euro 6 which will be implemented in September 2014. Improved fuel efficiency is envisaged to be a direct contributory factor in reducing harmful emissions among other factors. Therefore, reduction of frictional losses in contact conjunctions is progressively an important issue. The compression ring-bore conjunction is responsible for consuming almost 5% of fuel energy. One intensely researched area is enhancement of tribological performance through surface texturing of contacting solid surfaces in order to retain micro-reservoirs of lubricant in regions which are prone to poor lubrication, for example in piston-cylinder system 1,2. The current work comprises of a validated numerical model which has been created for analysis of surface texturing in the piston ring cylinder liner contact. The model employs a two dimensional solution of Reynolds equation as well as the inclusion of Greenwood and Tripp boundary friction model 3. The model is used to investigate the underlying mechanism of lubrication with textured surfaces. The understanding of surface texturing developed during this study enables design and positioning of textured patterns in piston ring - cylinder liner contact.