Dynamic Friction in Cam/Tappet Lubrication

Helden, A. K. van; Meer, R. J. van der; Staaden, J. J. van; Gelderen, E. van

doi:10.4271/850441

Cited by 12 publications

(4 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition to the work referenced above on research into the measurement of total engine friction, a number of researchers have also investigated friction losses in individual engine components (such as valve trains [14][15][16][17][18][19][20][21][22] and the piston assembly [23][24][25][26][27][28][29][30] ).…”

Section: Mixed/boundary Friction In Different Engine Componentsmentioning

confidence: 99%

How much mixed/boundary friction is there in an engine — and where is it?

Taylor

Morgan

Mainwaring

et al. 2019

Proceedings of the Institution of Mechanical Engineers, Part J:

View full text Add to dashboard Cite

Automotive engines are believed to operate predominantly in the hydrodynamic regime, as evidenced by the (1) the successful strategy of reducing lubricant viscosity to reduce engine friction and improve vehicle fuel consumption, and (2) for most engine operating conditions, direct measurements of engine friction (either motored or fired) find that engine friction increases with increasing engine speed. However, certain components in an engine are known to operate mainly in the mixed/boundary lubrication (e.g. the valve train) and other components (such as the piston rings) operate in the mixed/boundary regime for a portion of the time. In order to quantify the amount of mixed/boundary lubrication in an engine, and in the individual components of the engine, motored and fired friction tests have been carried out for a range of lubricants (of differing viscosity grade, and with/without friction modifier additives). A full discussion of the implications of this work, which includes the impact of fuel dilution and “running-in” is included with insights given into how the work reported here guides the development of future fuel-efficient engine lubricants.

show abstract

Section: Mixed/boundary Friction In Different Engine Componentsmentioning

confidence: 99%

How much mixed/boundary friction is there in an engine — and where is it?

Taylor

Morgan

Mainwaring

et al. 2019

Proceedings of the Institution of Mechanical Engineers, Part J:

View full text Add to dashboard Cite

show abstract

“…Typical experimental research works would aim at solving a particular problem and for a given fuel, but they provide little basis for generalized science-base approaches. Some relevant works included setups to measure cam friction torque by a spring system which minimized friction between the tappet and the guide [9], and to assess valve-train friction by measuring driving torque while successively removing components [10]. Wakuri et al [11] measured friction force on the tapped by strain gage techniques, and Choi et al [12] used the electrical capacitance method on the cam-tappet contact to determine oil film thickness and friction force.…”

Section: Introductionmentioning

confidence: 99%

Tribological Effects of Mineral-Oil Lubricant Contamination with Biofuels: A Pin-on-Disk Tribometry and Wear Study

Shanta

Soloiu

2011

Advances in Tribology

View full text Add to dashboard Cite

Use of biodiesel produces engine oil dilution because of unburned biodiesel impinging on cold walls of the combustion chamber, being scrapped to the oil pan, and leading to changes of oil friction, wear and lubricity properties. In this paper, mixtures of SAE 15W-40 oil, which were contaminated by known percentages of the biodiesels from canola oil, peanut oil, soybean oil, and chicken fat, were tested in a pin-on-disk tribometer. A contact was employed of AISI 1018 steel disk and AISI 316 stainless-steel ball for pin material, and friction force and specific wear were measured. Wear on the disk surfaces showed that any degree of mineral-oil dilution by the tested biodiesels reduces the wear protection of engine oil even at small mixture percentages. However, these reductions were not substantially different than those observed for same percentages of dilution of mineral oil by fossil diesel. The tested mixture of oil contaminated with animal fat feedstock (e.g., chicken fat) biodiesel showed the best wear behavior as compared to those for the other tested mixtures (of mineral oil with vegetable feedstock biodiesel dilutions). Obtained results are discussed as baseline for further studies in a renewable energy multidisciplinary approach on biofuels and biolubes.

show abstract

“…Due to the high proportion of friction within the valve train, there is a potential for savings, especially in the cam-tappet contact. In order to understand the contact conditions, experimental work has been concerned with determining the contact normal forces, lubrication gap heights or time-dependent friction values [8,9]. Experimental work by KANO [10] and DOBRENIZKI [11] investigated the potential for the friction reduction of DLC coatings in cam-tappet contacts under conditions close to the application on model test rigs.…”

Section: Introductionmentioning

confidence: 99%

Understanding Friction in Cam–Tappet Contacts—An Application-Oriented Time-Dependent Simulation Approach Considering Surface Asperities and Edge Effects

Orgeldinger

Tremmel

2021

Lubricants

View full text Add to dashboard Cite

With the increasing challenges of climate change and scarce resources, the development of sustainable and energy-efficient technical systems is becoming increasingly important. In many applications, the friction losses occurring in contacts have a decisive influence on the overall efficiency. At this point, tribological contact optimization can make an important contribution to increasing the efficiency of technical systems. However, improvements are often associated with a considerable experimental effort. To reduce the development time, additional simulation models can be applied to predict the tribological behavior. This requires the closest possible approximation of the real contact within a numerical model. This paper presents a simulation approach for the time-dependent simulation of a cam–tappet contact. The simulation uses realistic operating conditions as they arise in the valve train of internal combustion engines. The influence of edge effects on the friction behavior is considered by a scaled calculation area and the influence of the surface roughness is investigated using stochastic asperity models. It is shown that the tribological behavior within the contact strongly depends on the surface properties and the load spectrum used. In addition, edge effects on the sides of the contact area have a clear influence on the pressure and film thickness distribution.

show abstract

Dynamic Friction in Cam/Tappet Lubrication

Cited by 12 publications

References 6 publications

How much mixed/boundary friction is there in an engine — and where is it?

How much mixed/boundary friction is there in an engine — and where is it?

Tribological Effects of Mineral-Oil Lubricant Contamination with Biofuels: A Pin-on-Disk Tribometry and Wear Study

Understanding Friction in Cam–Tappet Contacts—An Application-Oriented Time-Dependent Simulation Approach Considering Surface Asperities and Edge Effects

Contact Info

Product

Resources

About