Friction and temperature mapping of environmentally acceptable gear oils

Authors

• Reza Bayat Tribology and Machine Elements, Materials Science and Environmental Engineering, Faculty of Engineering and Natural Sciences, P.O. Box 589, 33014 Tampere University, Tampere, Finland https://orcid.org/0000-0002-6479-5186
• Arto Lehtovaara Tribology and Machine Elements, Materials Science and Environmental Engineering, Faculty of Engineering and Natural Sciences, P.O. Box 589, 33014 Tampere University, Tampere, Finland https://orcid.org/0000-0003-2548-3128

DOI: https://doi.org/10.30678/fjt.96048

Keywords:

Elastohydrodynamic lubrication; Environmentally acceptable lubricant; Temperature map; Friction map; Gear oil

Abstract

In recent years, environmental issues have raised the demand to protect the environment against the pollution caused by the uncontrolled spillage of lubricating oils. One solution is using Environmentally Acceptable Lubricants (EALs), however, these oils are more expensive than the common mineral oils. The consumers require to test the oil performance using test machines but testing in real machines is costly and time-consuming. Small test machines like ball-on-disc have been previously used for friction mapping and ranking gear oils. In this paper, the friction maps are measured from 0.65 GPa to 1.25 GPa, and temperature maps are devised to experimentally simulate the gear contact along the line of action. Results illustrate that EALs can provide up to 60 % better frictional efficiency that leads to 20 ^oC cooler oil temperature in high-pressure contacts operating under elastohydrodynamic lubrication (EHL) regime.