Experimental study of the effect of additive on the tribological properties journal bearing under running‐in and start‐up or shut‐down stages

Abstract

PurposeThe purpose of this paper is to study the effects of additive on the tribological properties such as friction coefficient and wear loss in the journal bearings during start‐up (or shut‐down) and running‐in periods.Design/methodology/approachIn this study, fully formulated commercial engine mineral oil (SAE 20W50) and commercial oil additives (3 per cent) added into this oil were tested to determine the tribological performances such as friction coefficient, wear loss and the effect of the additive on protective layers formed on the sliding bearing's surfaces.FindingsThis study presents an experimental procedure for obtaining practical results pertaining to the tribological performance of the journal bearing under running‐in and start‐up or shut down stages. Also, in this study, the authors have attempted to show the linkage between the oil additive and the running conditions such as running‐in and start‐up and shut‐down in effecting performance of the journal bearing. It is well known that one of the roles of an additive is to form a protective layer to reduce friction coefficient in lubricated contacts.Originality/valueThe paper is of value in presenting an experimental procedure for obtaining practical results pertaining to the tribological performance of the journal bearing under running‐in and start‐up or shut down stages.