How lubricant formulations and properties influence the performance of rotorcraft transmissions under loss of lubrication conditions. (November 2020)

• Record Type: Journal Article
• Authors: Mohamed Faruck, Azhaarudeen Anifa; Hsu, Chia-Jui; Doerr, Nicole; Weigand, Michael; Gachot, Carsten
• Is Part Of: Tribology international. Volume 151(2020)
• Publication Date: 2020-11
• Subjects: Gears -- Scuffing -- Starved -- Zinc dialkyldithiophosphate -- Tricresylphosphate; Tribology -- Periodicals; 621.89
• DOI: 10.1016/j.triboint.2020.106390
• Languages: English
• ISSNs: 0301-679X

Abstract

Abstract: Loss of lubrication (LOL) in a rotorcraft transmission causes erratic degradation of drivetrain components due to direct surface contact thereby increasing the frictional heat in the system. This article studies the ability of synthetic and mineral-based lubricating oils typically used in the aviation industry regarding their physical properties, chemical composition, and detailed chemical structure to extend the longevity of the rotorcraft transmissions in the event of LOL. The lubricating oils were subjected to boundary lubrication tests using a FZG gear test rig and two lab-scale tribometers, cylinder-on-ring and ball-on-disc. The results provide an enhanced ranking of the selected lubricating oils based on their load-carrying capacity and scuffing resistance under LOL conditions complemented by the consideration of the oil chemistry. Highlights: Ranking of aviation lubricating oils based on their load-carrying capacity and resistance to scuffing. Possible to investigate contacts under starved lubrication condition. Evaluation of endurance of boundary lubricating films under oil starvation. Improved functioning of the contacts by tribofilm under lubricant starvation.