Piston ring friction in internal combustion engines

Wakuri, Yutaro; Hamatake, Toshiro; Soejima, Mitsuhiro; Kitahara, Tatsumi

doi:10.1016/0301-679x(92)90027-k

Cited by 65 publications

(53 citation statements)

References 11 publications

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“…However, the non-textured frictional response then increases continuously throughout the stroke, reaching its maximum close to the reversal point. This behaviour of the non-textured specimen has also been observed by previous researchers [34,35] and in this case demonstrates the beneficial effect of texture in relieving friction build-up.…”

Section: Transient Response Of Friction To Pockets In the Boundary Ansupporting

confidence: 89%

The Transient Friction Response of a Laser-Textured, Reciprocating Contact to the Entrainment of Individual Pockets

et al. 2016

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To shed light on the mechanisms with which surface texture improves the tribological performance of piston-liner contacts, we have measured the transient friction response as individual pockets pass through a reciprocating sliding contact. Tests were performed at different sliding speeds and results compared to those from a non-textured, reference specimen under different lubrication regimes. At low speed when the contact is in the boundary regime, friction force falls abruptly as each pocket leaves the contact zone, before gradually returning to an approximately steady-state value. This suggests that each pocket acts to temporarily increase the film thickness, which then decays to its non-textured value as oil is squeezed out. At higher speeds, friction is seen to reduce in a stepwise fashion, since the period between pockets being entrained is less than the time taken for the film to decay. In addition, friction results obtained when the contact is operating in the middle of the mixed regime point to a temporary film thickness collapse as the pocket enters the contact, and this agrees with recent modelling predictions. At higher speeds, the compound effect of successive pockets is to shift the contact to the right on Stribeck curve. These results imply that each pocket gives rise to an increase in film thickness that is both short-lived and small in magnitude (we estimate a few tens of nm). However, the resulting effect on friction can be significant (up to 82 % in this study) for two reasons: (1) provided the pocket frequency is sufficiently high, each successive pocket entrainment builds the film up without there being time for it to reduce back to its steady-state value; (2) when the contact is in the mixed regime, the Stribeck curve is at its steepest and friction is therefore most sensitive to film thickness changes. This has important practical implications in that pocket spacing on piston liners should be varied as a function of reciprocating sliding speed.

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Section: Transient Response Of Friction To Pockets In the Boundary Ansupporting

confidence: 89%

The Transient Friction Response of a Laser-Textured, Reciprocating Contact to the Entrainment of Individual Pockets

et al. 2016

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“…In 1979 it was estimated that approximately 30% of the automotive fuel consumed in the United States was spent on trips of 5 miles or less (Marshall 1979 A study by Fukuoka University in 1992 detailing the frictional behaviour of the piston assembly through both numerical and experimental investigation recognised that decreasing piston ring friction was an important way of improving the mechanical efficiency of the engine. They broadly state that for a piston ring pack with five piston rings, as a means of reducing the friction loss it is effective to simply decrease the number of piston rings (Wakuri, Hamatake et al 1992). …”

Section: Other Attempts At Increasing Fuel Economymentioning

confidence: 99%

In-Cylinder Fuel and Lubricant Effects on Gasoline Engine Friction

Smith

Priest

Taylor

et al. 2005

World Tribology Congress III, Volume 2

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Reducing engine friction remains an important goal of the automotive industry. Reduced engine friction has been partly achieved by using low viscosity, friction modified lubricants, reducing the energy required to shear the fluid in the hydrodynamic lubrication regime (which is the primary lubrication mode in the piston assembly). It has long been understood that the piston ring / cylinder liner interface is responsible for a significant proportion of engine friction and can significantly influence the fuel consumption of an engine. This paper describes research conducted to develop understanding of both the interfacial relationship of the compression ring and cylinder liner and the synergistic relationship of fuel and lubricant at the top ring zone of a single cylinder gasoline engine. A portfolio of engine testing, laboratory work and computer simulation has been conducted.

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“…Reduction of friction is a key factor in improving fuel consumption and wear performance. Appropriate surface roughness is one of the factors that can help to reduce friction in the piston/cylinder system and hence has received a great deal of attention in the literature [2][3][4][5]. It was found that the effect of RMS roughness is significant when the oil film is thin.…”

Section: Introductionmentioning

confidence: 98%

A Novel Method for Quantitative Determination of Ultra-low Wear Rates of Materials, Part II: Effects of Surface Roughness and Roughness Orientation on Wear

Shakhvorostov

Lennard

et al. 2008

Tribol Lett

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A novel method of measurement of the very low wear-rates of materials in the ultra-mild wear regime, which involves the use of implanted gold as a marker, was used to understand the effects of surface roughness and roughness orientation on wear under reciprocating sliding conditions. AISI 1095 steel coupons with various Vickers hardness values and different surface roughness and roughness orientation relative to the sliding direction were tested under the same sliding conditions. It was found that parallel sliding causes more wear compared with transverse sliding for the harder samples (Vickers hardness (VH); 450 HV, 650 HV and 1000 HV). Furthermore, the average friction coefficient of parallel sliding is also higher than that of transverse sliding for these samples. Severe wear takes place when the samples are too soft (250 HV), resulting in the complete loss of implanted gold. Surface topographic images were taken before and after the wear tests. It was found that parallel sliding dramatically increases the surface roughness, while transverse sliding does not increase the surface roughness for harder samples (450 HV, 650 HV and 1000 HV). For the soft sample (250 HV), the surface roughness increases significantly under parallel or transverse sliding.

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Piston ring friction in internal combustion engines

Cited by 65 publications

References 11 publications

The Transient Friction Response of a Laser-Textured, Reciprocating Contact to the Entrainment of Individual Pockets

The Transient Friction Response of a Laser-Textured, Reciprocating Contact to the Entrainment of Individual Pockets

In-Cylinder Fuel and Lubricant Effects on Gasoline Engine Friction

A Novel Method for Quantitative Determination of Ultra-low Wear Rates of Materials, Part II: Effects of Surface Roughness and Roughness Orientation on Wear

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