Today’s design trend is toward the higher power density, longer life, and higher energy efficiency of machines. This high-performance demand results in a more challenging operational environment for components. The failure probability of machine elements can be reduced by geometrical design, material improvement, or by using a better lubricant. Lubrication may be improved by using a better base oil to reduce the friction and temperature, and/or using additives that protect the surface against failures such as scuffing.
There exist standards that provide test methods for measuring the load-carrying capacity of lubricants, but these tests do not provide fundamental information on what occurs at a gear tooth in different locations. Also, these tests are expensive and time-consuming. On the other hand, a purely scientific approach is usually far from real conditions and cannot easily be used in an industrial approach. Thus, it is very important to develop a method that presents a scientific insight into scuffing and friction, while being applicable for an engineering approach.
Laboratory tests such as the ball-on-disc test may be used for primary screening and achieving scientifically analyzed findings that can be applied to actual components. It is also essential to conduct this preliminary laboratory testing using a fully formulated lubricant, such as industrial EALs (Environmentally Accepted Lubricants) whose usage is growing.
“Using industrial oils will be beneficial as the findings can be linked to the actual component tests. Additionally, it is critical to examine how the base oil and tribofilm contribute to gear lubrication,” Bayat says.
The doctoral dissertation of MSc (Tech) Reza Bayat in the field of Material Science and Environmental Engineering titled Evaluation of Gear Oils Lubrication Performance in a Rolling/Sliding Contact will be publicly examined in the Faculty of Engineering and Natural Sciences at Tampere University at 12 noon on Friday 06.05.2022 in Festia Building, Auditorium Pieni Sali 1. The Opponent will be Professor Jorge Humberto Oliveira Seabra, University of Porto, Portugal and Professor Ulf Olofsson, Royal Institute of Technology (KTH), Sweden. The Custos will be Professor Arto Lehtovaara from Faculty of Environmental Engineering and Natural sciences.
The dissertation is available online at https://urn.fi/URN:ISBN:978-952-03-2358-5.