The effect of kinematic conditions on film thickness in compliant lubricated contact

The effect of kinematic conditions on film thickness in compliant lubricated contact

WoS Article

The present paper deals with an investigation of film formation in compliant lubricated contact. Despite these contacts can be found in many applications of daily life including both biological and technical fields, so far little is known about the lubrication mechanisms inside the contacts. The main attention is paid to the effect of kinematic conditions on central film thickness. For this purpose, fluorescent microscopy method was employed. Experiments were realized in ball-on-disc configuration, while the ball was made from rubber and the disc was from optical glass. The contact was lubricated by glycerol and polyglycol to examine the effect of fluid viscosity. The measurements were conducted under pure rolling and rolling/sliding conditions. The entrainment speed varied from 10 to 400 mm/s and constant load of 0.2 N was applied. Experimental results were compared with two theoretical predictions derived for I-EHL regime. It was found that the thickness of lubricating film gradually increases with increasing entrainment speed, which corresponds to theoretical assumptions. Against expectations, evident influence of slide-to-roll ratio on film formation was observed. In the last part of the paper, some limitations of this study are discussed and several recommendations for further methodology improvement are suggested.

The present paper deals with an investigation of film formation in compliant lubricated contact. Despite these contacts can be found in many applications of daily life including both biological and technical fields, so far little is known about the lubrication mechanisms inside the contacts. The main attention is paid to the effect of kinematic conditions on central film thickness. For this purpose, fluorescent microscopy method was employed. Experiments were realized in ball-on-disc configuration, while the ball was made from rubber and the disc was from optical glass. The contact was lubricated by glycerol and polyglycol to examine the effect of fluid viscosity. The measurements were conducted under pure rolling and rolling/sliding conditions. The entrainment speed varied from 10 to 400 mm/s and constant load of 0.2 N was applied. Experimental results were compared with two theoretical predictions derived for I-EHL regime. It was found that the thickness of lubricating film gradually increases with increasing entrainment speed, which corresponds to theoretical assumptions. Against expectations, evident influence of slide-to-roll ratio on film formation was observed. In the last part of the paper, some limitations of this study are discussed and several recommendations for further methodology improvement are suggested.

compliant contact; isoviscous-elastohydrodynamic lubrication; film thickness; fluorescence microscopy; kinematic conditions

compliant contact; isoviscous-elastohydrodynamic lubrication; film thickness; fluorescence microscopy; kinematic conditions

NEČAS, D.; JAROŠ, T.; DOČKAL, K.; ŠPERKA, P.; VRBKA, M.; KŘUPKA, I.; HARTL, M.

2019

01.09.2018

The American Society of Mechanical Engineers

USA

0742-4787

JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME

140

5

United States of America

1

8

8

http://tribology.asmedigitalcollection.asme.org/article.aspx?articleid=2674750

Necas_Journal of Tribology