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Oil Transport Analysis of a Cylinder Deactivation Engine
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 12, 2010 by SAE International in United States
Annotation ability available
Engine cylinder deactivation is used to save engine pumping loss but raises oil consumption concerns for the deactivated cylinders. In this paper, general mechanisms of oil transport via piston rings are reviewed. The characteristic of oil transport and oil accumulation in a cylinder deactivation mode through the piston ring path are analyzed. Suggestions to reduce the oil transport to the combustion chamber in a deactivated cylinder are discussed.
In a deactivated cylinder, the amount of oil brought into the combustion chamber by the top ring up-scraping due to the ring/bore conformability difference between intake stroke and compression stroke is much less compared to a firing cylinder. However, compared to a firing cylinder, a deactivated cylinder has more oil entering the combustion chamber through the top ring end gap and ring groove as a result of the lower cylinder gas pressure, lower ring temperature and more frequent top ring axial movements. Suggestions are given to reduce the net upward oil transport in a deactivated cylinder, including reducing the ring/groove clearances and the sizes of the ring gaps and drain-holes, reducing cylinder bore distortion, designing structures of the piston-lands and the oil drain-holes to enhance downward oil flow and restrict upward oil flow, reducing or eliminating positive static twist of the top ring, and limiting the overall oil supply from the bottom of the piston.
CitationMa, Z., "Oil Transport Analysis of a Cylinder Deactivation Engine," SAE Technical Paper 2010-01-1098, 2010, https://doi.org/10.4271/2010-01-1098.
- Yilmaz, E. Tian, T. Wong, V.W. Heywood, J.B. “The Contribution of Different Oil Consumption Sources to Total Oil Consumption in a Spark Ignition Engine,” SAE Technical Paper 2004-01-2909 2004
- Hitosugi, H. Nagoshi, K. Komada, M. Furuhama, S. “Study on Mechanism of Lubricating Oil Consumption Caused by Cylinder Bore Deformation,” SAE Technical Paper 960305 1996
- Usui, M. Murayama, K. Oogake, K. Yoshida, H. “Study of Oil Flow Surrounding Piston Rings and Visualization Observation,” SAE Technical Paper 2008-01-0795 2008
- Przesmitzki, S. Tian, T. “Oil Transport Inside the Power Cylinder During Transient Load Changes,” SAE Technical Paper 2007-01-1054 2007
- Saito, K. Igashira, T. Nakada, M. “Analysis of Oil Consumption by Observing Oil Behavior Around Piston Ring Using a Glass Cylinder Engine,” SAE Technical Paper 892107 1989
- Thirouard, B. Tian, T. “Oil Transport in the Piston Ring Pack (Part I): Identification and Characterization of the Main Oil Transport Routes and Mechanisms,” SAE Technical Paper 2003-01-1952 2003
- Vokac, A. Tian, T. “An Experimental Study of Oil Transport on the Piston Third Land and the Effects of Piston and Ring Designs,” SAE Technical Paper 2004-01-1934 2004
- Thirouard, B. Tian, T. “Oil Transport in the Piston Ring Pack (Part II): Zone Analysis and Macro Oil Transport Model,” SAE Technical Paper 2003-01-1953 2003
- Tian, T. “Dynamic behaviours of piston rings and their practical impact. Part 1: ring flutter and ring collapse and their effects on gas flow and oil transport” Proc Instn Mech Engrs 216 Engineering Triblogy 209 227