Metallurgical and Metrological Examinations of the Cylinder Liner-Piston Ring Surfaces After Heavy Duty Diesel Engine Testing©

1999 ◽  
Vol 42 (1) ◽  
pp. 116-125 ◽  
Author(s):  
M. Shuster ◽  
F. Mahler ◽  
D. Crysler
Keyword(s):  
Diesel Engine ◽  
Piston Ring ◽  
Cylinder Liner ◽  
Heavy Duty ◽  
Heavy Duty Diesel Engine ◽  
Heavy Duty Diesel ◽  
Engine Testing

Tribological assessment of NiCr, Al2O3/TiO2, and Cr3C2/NiCr coatings applied on a cylinder liner of a heavy-duty diesel engine

2020 ◽  
pp. 146808742093016
Author(s):  
Onur Biyiklioğlu ◽  
Mustafa Ertunc Tat
Keyword(s):  
Cast Iron ◽  
Diesel Engine ◽  
Wear Rate ◽  
Gray Cast Iron ◽  
Cylinder Liner ◽  
Gray Cast ◽  
Economic Evaluations ◽  
Heavy Duty ◽  
Heavy Duty Diesel Engine ◽  
Heavy Duty Diesel

Internal combustion engines consume about 90% of fuel refined from crude oil which supplies 30% of the annual global flow of energy. Heavy-duty diesel engines are the primary source of power used in highways, marine, railroads, and power stations. The right coating can improve the tribological properties of cylinder liners and increase the mechanical efficiency of an engine. Also, it can help to extend the maintenance periods, and enhance the reliability of the vehicles. In this research, tribological and economic evaluations were performed for coated and uncoated substrates from a cylinder liner of a heavy-duty diesel engine, aiming to lower friction, wear rate, and maintenance cost. A reciprocating friction test was conducted under dry condition using Wolfram carbide (tungsten carbide) ball applied a 10 N normal load on a ball on disk geometry. The cylinder liner was made of gray cast iron, and the substrates obtained were coated with three different coating materials (Cr3C2/NiCr, NiCr, and Al2O3/TiO2) through the thermal spray and high-velocity oxy-fuel coating process. Tribological evaluations showed that the substrates coded with Al2O3/TiO2 and Cr3C2/NiCr had the lowest friction coefficient and wear rate. The most economical coating was Al2O3/TiO2, being able to supply about 61% lower coefficient of friction and 94% less wear rate relative to the uncoated sample, for the price of one-third of the Cr3C2/NiCr coating and one half of a new gray cast iron cylinder liner.

The Dynamics of Second Ring Flutter and Collapse in Modern Diesel Engines

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Chao Cheng ◽  
Harold Schock ◽  
Dan Richardson
Keyword(s):  
Diesel Engine ◽  
Gas Flow ◽  
Piston Ring ◽  
Sensitivity Study ◽  
The Other ◽  
Heavy Duty ◽  
Oil Consumption ◽  
Ring Dynamics ◽  
Heavy Duty Diesel Engine ◽  
Heavy Duty Diesel

Second ring fluttering and radial ring collapse are recognized as having significant influences on engine blowby and oil consumption. As the gas flow is coupled with the piston ring motion, understanding the ring dynamics is important for understanding not only the engine blowby mechanism, but also oil consumption mechanisms and how to control them. Only second ring flutter and collapse that occurs around the top dead center (TDC) firing conditions is examined in this paper based on a modern heavy-duty diesel engine. However, the principles described are equally applicable to all engines. First, the authors describe the fundamental mechanisms of how second ring fluttering and radial ring collapse occur. This is described by examining the forces that are acting on the second ring. Then, two cases are shown. One case shows second ring flutter and the other case shows stable second ring motion. The reasons for these two different cases are explained, including the effect of static twist and the end gaps of the rings. A sensitivity study was performed to evaluate the effect of changing the top and second ring end gaps on ring lift. It was shown how the gaps could affect the second ring flutter and ring collapse. It is concluded that the second ring will be more likely to flutter or collapse if it has a negative static twist, if the second ring end gap is large, and/or if the top ring end gap is small. If the second ring does not flutter, it may still be possible to design the ring pack such that there is not any reverse blowby. However, this must be carefully studied and controlled or the second land pressures will be too high, resulting in reverse blowby and/or top ring lifting.

Texture-induced effects causing reduction of friction in mixed lubrication for twin land oil control rings

2017 ◽  
Vol 232 (2) ◽  
pp. 166-178 ◽  
Author(s):  
Markus Söderfjäll ◽  
Roland Larsson ◽  
Pär Marklund ◽  
Andreas Almqvist
Keyword(s):  
Numerical Simulation ◽  
Diesel Engine ◽  
Major Part ◽  
Cylinder Liner ◽  
Mixed Lubrication ◽  
Heavy Duty ◽  
Cavitation Model ◽  
Heavy Duty Diesel Engine ◽  
Liner Surface ◽  
Heavy Duty Diesel

Piston rings are responsible for a major part of the frictional losses in a heavy-duty diesel engine. Such losses can be reduced by applying texture, such as dimples, on the cylinder liner surface. This paper investigates the effect of such texture on the friction between a land of the oil control ring and a textured cylinder liner via numerical simulation. A simulation model considering inertia and mixed lubrication together with a mass-conserving cavitation model is developed. The model is used to determine the dimple parameters that yield the lowest amount of friction for a specific oil control ring of a heavy-duty diesel engine.

The Dynamics of Second Ring Flutter and Collapse in Modern Diesel Engines

2014 ◽  
Author(s):  
Chao Cheng ◽  
Harold Schock ◽  
Dan Richardson
Keyword(s):  
Diesel Engine ◽  
Gas Flow ◽  
Piston Ring ◽  
Sensitivity Study ◽  
The Other ◽  
Heavy Duty ◽  
Oil Consumption ◽  
Ring Dynamics ◽  
Heavy Duty Diesel Engine ◽  
Heavy Duty Diesel

Second ring fluttering and radial ring collapse are recognized as having significant influences on engine blowby and oil consumption. As the gas flow is coupled with the piston ring motion, understanding the ring dynamics is important for understanding not only the engine blowby mechanism, but also oil consumption mechanisms and how to control them. Only second ring flutter and collapse that occurs around the top dead center firing conditions is examined in this paper based on a modern heavy-duty diesel engine. However, the principles described are equally applicable to all engines. First, the authors describe the fundamental mechanisms of how second ring fluttering and radial ring collapse occurs. This is described by examining the forces that are acting on the second ring. Then, two cases are shown. One case shows second ring flutter and the other case shows stable second ring motion. The reasons for these two different cases are explained, including the effect of static twist and the end gaps of the rings. A sensitivity study was performed to evaluate the effect of changing the top and second ring end gaps on ring lift. It was shown how the gaps could affect the second ring flutter and ring collapse. It is concluded that the second ring will be more likely to flutter or collapse if it has a negative static twist, if the second ring end gap is large, and/or if the top ring end gap is small. If the second ring does not flutter, it may still be possible to design the ring pack such that there is not any reverse blowby. However, this must be carefully studied and controlled or the second land pressures will be too high, resulting in reverse blowby and/or top ring lifting.

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