Investigation of Wear Pattern in Piston Ring of an IC Engine

Piston Ring, as small as it appears, plays quite an important role in contribution to friction and wear in an IC engine. As a first approximation most wear models, have quantified wear of a piston ring in terms of total wear volume, total weight loss or depth of the wear scar with an underlined assumption that wear is uniform along the circumference. This research work presents the results of wear calculation of the top piston ring of an IC Engine by measuring piston ring profile at 9 different angular sections, constituting 8 sectors of piston ring. Piston ring profile was measured over axial width of the worn-out piston ring at 13 different locations along the axial direction for each of the 9 sections. Volume loss for each of the 8 sectors is calculated by comparing piston ring profile of worn-out piston ring with profile of new piston ring of same type. It is observed that the wear volume loss is different for different sectors. It can be inferred from wear pattern (volume loss) that different areas of piston rings undergo different regimes of lubrication. It is likely that different sectors of piston ring undergo boundary, mixed and hydrodynamic lubrication regimes to different extents along the circumference of the top piston ring.