On the importance of the experimental setup design in hydrodynamic journal bearing friction measurement

Gosar, Aleš (author), Klemenc, Jernej (author), Nagode, Marko (author), Oman, Simon (author)

Improving operating conditions and reducing the friction-related power losses of hydrodynamic journal bearings could lower emissions and contribute to efforts for a faster green transition. Experimental studies play an important role in evaluating and improving the performance of plain journal bearings. The concept of the experimental setup for friction measurements of journal bearings is well defined in the relevant standards, but the actual design is always left to the researchers conducting a particular study. Our study reveals that common practical assumptions about the frictional power losses caused by components of the experimental setup can lead to misleading conclusions about the measured coefficient of friction. The research premises were tested on the developed experimental setup using two methods for measuring the coefficient of friction and different load interfaces. In particular, the direct torque measurement using strain gauges on the shaft demonstrated the strongest correlation with theoretical values. However, the result was affected by the correct evaluation of the frictional losses of the support ball bearings. Conversely, the Stribeck curves showed that the combination of the indirect cantilever method and load interface with direct radial force application led to inferior results. The intricate interactions between setup components and unknown frictional conditions made straightforward geometric corrections challenging. The study encourages researchers in the field to critically assess their experimental setups and to rely on their own assessment of frictional losses.

• Language: English
• Keywords: plain journal bearing, coefficient of friction, frictional torque, experimental setup
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: 13 str.
• Numbering: Vol. 197, art. 109800
• PID: 20.500.12556/RUL-158197
• UDC: 539.92:531.4:621.8
• ISSN on article: 0301-679X
• DOI: 10.1016/j.triboint.2024.109800
• COBISS.SI-ID: 196777987
• Publication date in RUL: 29.05.2024

Record is a part of a journal

• Title: Tribology international
• Shortened title: Tribol. int.
• Publisher: Elsevier
• ISSN: 0301-679X
• COBISS.SI-ID: 26558976

Licences

• License: CC BY-NC 4.0, Creative Commons Attribution-NonCommercial 4.0 International
• Link: http://creativecommons.org/licenses/by-nc/4.0/
• Description: A creative commons license that bans commercial use, but the users don’t have to license their derivative works on the same terms.

Secondary language

• Language: Slovenian
• Keywords: drsni ležaji, eksperimentalno vrednotenje, koeficient trenja, preizkuševališče

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: P2-0182
• Name: Razvojna vrednotenja