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Running-in effects on friction of journal bearings under slow sliding speeds

Research output: Contribution to journalArticleScientificpeer-review


Original languageEnglish
JournalProceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology
Publication statusPublished - 2019
Publication typeA1 Journal article-refereed


Hydrodynamic thrust and journal bearings are facing challenges in modern heavy-duty machinery where full film lubrication cannot always be achieved or sustained. This is due to reasons such as start–stop operation, increased power density and the use of thinner lubricants. Although this leads to increased overall efficiency, bearings are operating more often under mixed lubrication conditions. This is why the running-in behavior of the bearing material is important. In this study, running-in behavior of traditional leaded tin bronze and its environmentally sustainable alternative, bimetal bismuth, was studied. Experimental friction tests were performed with journal bearings under full film and mixed lubrication conditions in order to find the Stribeck curves. The results are analyzed using frictional energy, and friction coefficient values based on continuous friction monitoring. Remarkable reduction of friction was observed with both bearing materials due to running-in.


  • Bearings, continuous monitoring, friction, hydrodynamic lubrication, journal bearing, running-in

Publication forum classification

Field of science, Statistics Finland