Base fluid parameters for elastohydrodynamic lubrication and friction calculations and their influence on lubrication capability

Larsson, Roland; Kassfeldt, Elisabet; Byheden, Åke; Norrby, Thomas

doi:10.1002/jsl.3000180302

Cited by 25 publications

(36 citation statements)

References 10 publications

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“…Film thickness is essentially established in a low-pressure region at the inlet side of the contact, whereas traction, for the most part, is generated by the shearing of the film in the high-pressure Hertz region of contact. The pressure-viscosity coefficient, a, quantifies the film-generating capability of a lubricant in tribological contacts at isothermal conditions [3,4]. This coefficient is very dependent on the chemical structure of the base oil [3,5,6] and could be modified using small quantities of additives.…”

Section: Introductionmentioning

confidence: 99%

“…The pressure-viscosity coefficient, a, quantifies the film-generating capability of a lubricant in tribological contacts at isothermal conditions [3,4]. This coefficient is very dependent on the chemical structure of the base oil [3,5,6] and could be modified using small quantities of additives. The universal pressure-viscosity coefficient, a film , defined by Bair et al [7] quantifies the general piezoviscous response relevant to Newtonian concentrated contact film forming.…”

Section: Introductionmentioning

confidence: 99%

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The Pressure–Viscosity Coefficient of Several Ionic Liquids

2008

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The choice of cation and anion in an ionic liquid (IL) as well as the design of ion side chains determine the fundamental properties of ILs, which permits creating tailor-made lubricants and lubricant additives. So, the study of the influence of molecular structure on thermophysical properties of ionic liquids is essential for their use in lubrication. Recent results from the literature, essentially based on ammonium, phosphonium, or imidazolium cations, are promising from the tribological point of view, but still new investigations should be performed, for example, in elastohydrodynamic lubrication (EHL), for which calculations of the universal pressure-viscosity coefficient, a film , and central thickness are needed. In this work viscosity and density data from the literature on broad pressure and temperature ranges for the ILs [C 4 C 1 im]PF 6 , [C 4 C 1 im]Tf 2 N, [C 4 C 1 im]BF 4 , [C 8 C 1 im]PF 6 , [C 8 C 1 im] BF 4 , [C 6 C 1 im]PF 6 , and [C 6 C 1 im]Tf 2 N are used to determine their a film values over a wide temperature range. The American Gear Manufacturers Association relation of the central thickness with the pressure viscosity coefficient is used to estimate the film-generating capability of these lubricants. Furthermore, an overview of the literature data on tribological and physical properties of the ionic liquids is presented.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The Pressure–Viscosity Coefficient of Several Ionic Liquids

2008

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“…Yokoyama and Spikes explored the film-forming properties of polyol esters, polyphenyl ethers, and their mixtures over a wide range of temperature [25]. Larsson et al studied a few base fluid parameters for elastohydrodynamic lubrication and friction calculations, and investigated their influences on lubrication capability [26]. Lord and Larsson reported the effects of slide-roll ratio and lubricant properties of a synthetic ester VG46 on elastohydrodynamic lubrication film thickness and traction, and suggested that the ester maintained a relatively thicker lubricant film during sliding than did the corresponding polyalphaolefin and mineral oils [27].…”

Section: Introductionmentioning

confidence: 99%

Elastohydrodynamic lubrication properties and friction behaviors of several ester base stocks

Zolper

Liu

et al. 2015

Friction

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This paper reports a series of studies on the lubricant properties, elastohydrodynamic film thickness, and coefficients of friction of several commercially available ester base stocks, i.e., diisooctyl phthalate (DIOP), diisodecyl phthalate (DIDP), diisotridecyl phthalate (DITDP), diisooctyl sebacate (DOS), diisotridecyl sebacate (DTDS), trihydroxymethylpropyl trioleate (TMPTO), and pentaerythritol tetraoleate (PETO). The results include densities and viscosities from 303 to 398 K, and elastohydrodynamic lubricant film thicknesses and friction in the boundary, mixed and full-film lubrication regimes measured at several temperatures, loads, and speeds. These ester base stocks have different lubrication abilities owing to their chain lengths, geometric configurations, and molecular rigidity. This study provides quantitative insight into the use of ester-based lubricants for low friction through the entire lubrication regime (boundary to full film) by utilization of suitable type and size of the ester base stocks.

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“…These values do not give enough information to choose the optimum lubricant for a lubricated contact [3]. In mec7hanical systems take place rolling, sliding and rolling/sliding contacts, therefore lubricants have to work the best possible in these operation conditions.…”

Section: Introductionmentioning

confidence: 99%

“…In order to avoid wear, it is necessary to keep the lubricant film thick enough to prevent any contact between the surfaces. Friction should be minimised in order to obtain as high efficiency as possible and pressure peaks should be as small as possible to avoid large sub-surface stresses and thus avoid pitting fatigue [3]. An equation that describe the influence of some parameters in lubricant film is the Hamrock-Dowson one (Equation 1) for elliptical conjunctions.…”

Section: Introductionmentioning

confidence: 99%

Tribological behaviour of polyalphaolefins: Wear and rolling‐contact fatigue tests

Rico

Cuervo

Battez

2003

J of Synthetic Lubrication

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SUMMARYPolyalphaolefin fluids are gaining rapid acceptance as high-performance lubricants and functional fluids because they have certain inherent, and highly desirable, characteristics relative to mineral oils. One of these characteristics is their low toxicity. It combined with excellent viscometrics and lubricity, have made low-viscosity PAO fluids an important component in lubricant formulations.Typical data found in product specifications for lubricants are the kinematic viscosity and the viscosity index. These values do not give enough information to choose the optimum lubricant for a lubricated contact. In mechanical systems take place rolling, sliding and rolling/sliding contacts, therefore lubricants have to work the best possible in these operation conditions.In this study are experimentally determined the L 50 , L 10 and Weibull´s slope () of polyalphaolefins with two different viscosities. This test was made on a four-ball machine (Stanhope Seta). Wear test also was made on a four-ball tester (Roxana) in order to measure the wear scar diameter (WSD), and the flash temperature parameter (FTP). Lubricants were identified through infrared spectroscopy, and ball´s pittings were observed with SEM.

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Base fluid parameters for elastohydrodynamic lubrication and friction calculations and their influence on lubrication capability

Abstract: In this study, base fluid parameters for elastohydrodynamic lubrication (EHL)

Cited by 25 publications

References 10 publications

The Pressure–Viscosity Coefficient of Several Ionic Liquids

The Pressure–Viscosity Coefficient of Several Ionic Liquids

Elastohydrodynamic lubrication properties and friction behaviors of several ester base stocks

Tribological behaviour of polyalphaolefins: Wear and rolling‐contact fatigue tests

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