Effect of cylinder deactivation on tribological performance of piston compression ring and connecting rod bearing. (April 2018)

• Record Type: Journal Article
• Authors: Morris, N.; Mohammadpour, M.; Rahmani, R.; Johns-Rahnejat, P.M.; Rahnejat, H.; Dowson, D.
• Is Part Of: Tribology international. Volume 120(2018)
• Page Start: 243
• Page End: 254
• Publication Date: 2018-04
• Subjects: Cylinder deactivation -- Piston compression ring -- Big-end bearing -- Friction -- Power loss; Tribology -- Periodicals; 621.89
• DOI: 10.1016/j.triboint.2017.12.045
• Languages: English
• ISSNs: 0301-679X

Abstract

Abstract: Thermo-mixed-hydrodynamics of compression rings and big-end bearings are presented. Frictional losses under normal engine operating conditions for a gasoline engine and those with cylinder deactivation (CDA) are predicted. With CDA, the combustion chamber pressure increases in the active cylinders, whilst some residual pressure remains in the deactivated ones. For the former, the increased in-cylinder temperatures reduce viscous friction, whilst reducing the load carrying capacity, promoting increased boundary interactions. In deactivated cylinders, lower contact temperatures yield increased viscous friction. Overall, a 5% improvement in expended fuel is expected with the application of CDA. However, 10% of these gains are expended due to increased friction. The study demonstrates the need to consider total system effects when introducing new technologies such as CDA. Highlights: The effect of Cylinder deactivation (CDA) technology on engine efficiency is presented. Combined mixed-thermo-hydorodynamics of piston compression ring and big end bearing is outlined. First ever integrated analysis of the effect of CDA on frictional losses in both big end bearing and piston compression ring. With CDA some of gained fuel efficiency is expended in overcoming increased contact friction.