Non-Newtonian and running-in wear effects in journal bearings operating under mixed lubrication

Allmaier, Hannes; Sander, David Emanuel; Priebsch, Hans-Herwig; Witt, Mario; Füllenbach, T.; Skiadas, Athanassios

doi:10.1177/1350650115594191

Cited by 27 publications

(26 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The presented results give an overview of current research by the authors. The majority of the results are taken from recent publications and, therefore, we refer to the original publications for further reading [42,43,47,48,53].…”

Section: Simulation Resultsmentioning

confidence: 99%

“…The detailed derivation can be found in [47]. The values of the introduced coefficients are listed in Table 2 The viscosity characteristics obtained from the derived parameters are also shown in Viscosity-shear rate dependency for the 0W20 lubricant at different temperatures [48]; please note the logarithmic scale.…”

Section: Lubricant Properties At High Pressure and High Shear Ratementioning

confidence: 99%

“…Viscosity-temperature dependency for the 0W20 lubricant at different pressures[48]; please note the logarithmic scale.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Friction and Wear in Automotive Journal Bearings Operating in Today’s Severe Conditions

Sander¹,

Allmaier²,

Priebsch³

2016

Advances in Tribology

View full text Add to dashboard Cite

A current trend in the transport sector seeks to increase the vehicle efficiency and to cut fuel consumption which leads to new technologies and advancements in modern and future combustion engines. Some of these technical progresses lead to highly stressed engine parts and new challenges arise, particularly for journal bearings. The increasing thermal and mechanical load caused by downsized and turbocharged engines, friction reduction by employing low-viscosity lubricants and other emission reduction measures-for utilizing stop-start systems-put additional stress on the crankshaft journal bearings. This contribution focuses on highly stressed journal bearings which operate in the boundary, mixed and hydrodynamic lubrication regime. Therefore, measurements on a journal bearing test-rig are performed which allow an extensive verification of the numerical investigation. For the numerical analysis of friction and wear, a mixed elasto-hydrodynamic simulation approach is developed, which considers the elastic deformation of the contacting components, the complex rheological behaviour of the lubricant and metal-metal contact if the lubricant is unable to separate the contacting surfaces. Both the rheological data and the surface roughness parameters are obtained from measurements. The current challenges are studied in four application-oriented examples and the influencing parameters on a reliable friction and wear prediction are explored.

show abstract

Section: Simulation Resultsmentioning

confidence: 99%

Section: Lubricant Properties At High Pressure and High Shear Ratementioning

confidence: 99%

See 1 more Smart Citation

Friction and Wear in Automotive Journal Bearings Operating in Today’s Severe Conditions

Sander¹,

Allmaier²,

Priebsch³

2016

Advances in Tribology

View full text Add to dashboard Cite

show abstract

“…Metal-metal contact was also identified by simulation. As a consequence research on the running in process of journal bearings was conducted [33,34]. Complementary, the presented results are obtained from the same simulation approach yet discuss friction in severe mixed lubrication regime.…”

Section: Figure 1: Sketch Of a Stribeck Curve With Different Lubricatmentioning

confidence: 86%

Simulation of journal bearing friction in severe mixed lubrication – Validation and effect of surface smoothing due to running-in

Sander

Allmaier

Priebsch

et al. 2016

Tribology International

113

View full text Add to dashboard Cite

This paper focuses on the friction behavior of journal bearings operating from hydrodynamic to mixed lubrication regime where severe metal-metal contact occurs. Therefore, friction tests with two different static loads are carried out on the journal bearing test-rig from KS Gleitlager. The test results in form of Stribeck curves provide a solid base to proof the isothermal elastohydrodynamic simulation approach. The simulation approach solves the averaged Reynolds equation introduced by Patir and Cheng and considers metal-metal contact by using the Greenwood and Tripp contact model. All necessary surface parameters are derived from surface scans. No less essential in this approach are the experimentally identified lubricant properties under high pressure and high shear rate.The calculated friction torque matches the measurement results within the measurement uncertainty for a wide range of operation conditions. With the validated simulation approach the influence of surface smoothing due to metal-metal contact is discussed. Additionally, the limits of a constant boundary coefficient are identified and the effects of flow factors are presented.

show abstract

“…It is made available specifically for use in combustion engines and features a very high viscosity index (VI) without the necessity to add VI-improving additives. VI-improvers can cause a significant non-Newtonian behaviour [21][22][23][24] of the lubricant. Therefore, a lubricant without these is expected to maintain its high viscosity also in the presence of locally high shear rates, which is an advantage for highly loaded contacts.…”

Section: The Tested Lubricantsmentioning

confidence: 99%

Friction Reduction Tested for a Downsized Diesel Engine with Low-Viscosity Lubricants Including a Novel Polyalkylene Glycol

et al. 2017

View full text Add to dashboard Cite

Abstract:With the increasing pressure to reduce emissions, friction reduction is always an up-to-date topic in the automotive industry. Among the various possibilities to reduce mechanical friction, the usage of a low-viscosity lubricant in the engine is one of the most effective and most economic options. Therefore, lubricants of continuously lower viscosity are being developed and offered on the market that promise to reduce engine friction while avoiding deleterious mixed lubrication and wear. In this work, a 1.6 L downsized Diesel engine is used on a highly accurate engine friction test-rig to determine the potential for friction reduction using low viscosity lubricants under realistic operating conditions including high engine loads. In particular, two hydrocarbon-based lubricants, 0W30 and 0W20, are investigated as well as a novel experimental lubricant, which is based on a polyalkylene glycol base stock. Total engine friction is measured for all three lubricants, which show a general 5% advantage for the 0W20 in comparison to the 0W30 lubricant. The polyalkylene glycol-based lubricant, however, shows strongly reduced friction losses, which are about 25% smaller than for the 0W20 lubricant. As the 0W20 and the polyalkylene glycol-based lubricant have the same HTHS-viscosity , the findings contradict the common understanding that the HTHS-viscosity is the dominant driver related to the friction losses.

show abstract

Non-Newtonian and running-in wear effects in journal bearings operating under mixed lubrication

Cited by 27 publications

References 18 publications

Friction and Wear in Automotive Journal Bearings Operating in Today’s Severe Conditions

Friction and Wear in Automotive Journal Bearings Operating in Today’s Severe Conditions

Simulation of journal bearing friction in severe mixed lubrication – Validation and effect of surface smoothing due to running-in

Friction Reduction Tested for a Downsized Diesel Engine with Low-Viscosity Lubricants Including a Novel Polyalkylene Glycol

Contact Info

Product

Resources

About