Small Engine Piston Ring Design for Reduced Oil Consumption

1988 ◽  
Author(s):  
Robert C. Fesser
Author(s):  
J. L. Hepworth

After reviewing the more usual types of piston failures such as breakage, seizure, ring sticking, land breakage, land scuffing, and groove destruction, means are suggested for their avoidance. There follows a consideration of the limiting factors of piston life, as indicated by the oil consumption of the engine. Dangers of overscraping new engines are emphasized and a method of retaining a minimum consumption over a long life is suggested. Examination of the rates of wear of the various components of the piston assembly leads to the conclusion that the top compression ring is the weakest point. Service test results with different piston ring materials are given and improved materials are suggested. Chromium-plated piston rings give the best results and are recommended for use as the upper compression ring. Finally, suggestions are given for designing the successful oil engine piston with a strong recommendation for the use of 12 per cent silicon alloy material and an adequate path for heat flow from the piston crown to the ring zone. Gudgeon-pin design is an important feature and design formulae are given. In summarizing, a model piston ring layout is given in detail.


Author(s):  
Matthias Stark ◽  
Richard Mittler

Approaching a characterization of different contributors to the lube oil balance of an engine becomes important when aiming at enhancing lubrication performance and reducing its contribution to exhaust gas emissions. It is essential to quantify relevant data helping to determine lubrication losses related to particular tribosystem components. Recent activities focused on rating distinct tribosystem component effects on their contribution to total lube oil consumption and the possibility to most effectively modify those. This paper thus describes the most effective tribosystem component modifications, consisting of the application of a substantially modified piston ring pack and the introduction of lube oil accumulating grooves in order to considerably enhance lubrication performance. A proper prediction of piston ring pack dynamics and tribodynamic effects on the lube oil film is essential to design a superior piston ring pack in terms of an optimized piston running behaviour and lube oil transportation. One major step designing such a ring pack is based on the consequent application of a novel 3D piston ring pack simulation tool to enhance lube oil transportation characteristics and distribution. Lube oil accumulating grooves are introduced to reduce lubrication losses due to so called ring pack spray. The ring pack spray is a result of accumulated lubricant in the pressurized piston ring pack expanding into the scavenge air receiver during the scavenging phase. Mentioned effect was analysed in detail in order to determine the amount of related lubricant losses. Investigations in this context lead to the application of lube oil accumulating grooves and hence can be considered an important design aspect to reduce total lube oil consumption. Tribosystem performance validation was performed on the basis of the application of an SO2 tracing technology on a full scale engine test in order to determine relevant tribosystem component modifications in real time. The sulphur content of fuel and lube oil considerably influences the formation of particulate matter in the exhaust gas, following chemical reactions of sulphur oxidation. Hence detecting SO2 in the exhaust gas is a direct measure to determine the amount of lubricant in the exhaust gas composition. Finally this report demonstrates measurement results describing the superior performance of the modified tribosystem.


2020 ◽  
Vol 2020 (0) ◽  
pp. J07119
Author(s):  
Bitong TAN ◽  
Tomoya TAKAKI ◽  
Yasuo MORIYOSHI ◽  
Tatuya KUBOYAMA
Keyword(s):  

1929 ◽  
Vol 1 (3) ◽  
pp. 99-102
Author(s):  
W.A. Oubridge

1993 ◽  
Author(s):  
Hideki Yoshida ◽  
Masaki Yamada ◽  
Hiroyuki Kobayashi

Author(s):  
Cristiana Delprete ◽  
Abbas Razavykia

Internal combustion engines are at present used as the major power sources for transportation and power generator. Improvement of the internal combustion engine efficiency is expected due to strict environmental standards and energy costs. Any reduction in oil consumption, friction power losses and emissions results in improving engines’ performance and durability. Automotive industries have intense passion to increase engines’ efficiency to meet the fuel economy and emission standards. Many studies have been conducted to develop reliable approaches and models to understand the lubrication mechanisms and calculate power losses. This review paper summarizes the synthesis of the main technical aspects considered during modeling of piston ring–liner lubrication and friction losses investigations. The literature review highlights the effects of piston ring dynamics, components geometry, lubricant rheology, surface topography and adopted approaches, on frictional losses contributed by the piston ring-pack.


2003 ◽  
Vol 125 (4) ◽  
pp. 1081-1089 ◽  
Author(s):  
Y. Piao ◽  
S. D. Gulwadi

The role of cylinder bore shapes in engine performance has been the subject of several studies in recent years. In particular, the influence of bore distortion on oil consumption under high speed conditions has generated significant interest. In this paper, the effect of an axial bore profile on radial dynamics of a ring is investigated. Radial ring motions within grooves due to the axial bore profile can generate significant inertial effects and also have an impact on ring end-gap sizes and lubrication conditions at the ring-liner interfaces. The magnitude of such effects is dependent on the ring-pack configuration, engine operating conditions (speed and load) and axial bore profile details. These issues are investigated in this study due to their implication on engine oil consumption, friction and blow-by. The authors have developed an analytical expression to account for the effects of radial ring inertia due to an axial bore profile for implementation in a piston ring-pack simulation tool RINGPAK. Simulation results from a gasoline engine study are presented to illustrate the effects of engine speeds, ring tensions, and characteristics of axial bore profiles on ring radial dynamics and ring-liner lubrication. Relevant qualitative comparisons are made to experimental measurements available in the literature.


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