Gear power loss performance of biodegradable low-toxicity ester-based oils

• Type: Article in International Scientific Journal
• Date: 2008

Authors

Martins, R (Author) FEUP; Cardoso, N (Author) Other; Seabra, J (Author) FEUP

Journal

Title: Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology

Vol. 222

Pages: 431-440

ISSN: 1350-6501

Publisher: SAGE

Indexing

ISI Web of Knowledge - 18 Citations

ISI Web of Science

Scopus - 19 Citations

COMPENDEX

Scientific classification

FOS: Engineering and technology > Mechanical engineering

Other information

Authenticus ID: P-003-ZXV

DOI: 10.1243/13506501jet345

Abstract (EN): Environmental issues are leading to a growing interest in bio-lubricants, which can have similar or even better performance than mineral and synthetic oils. In this work, the power loss performance of two biodegradable, low toxicity, ester-based gear oils was evaluated and compared with a commercial mineral oil and an ester-based fluid containing zinc dialkyl dithio phosphate (ZDDP) additives. Power loss tests were performed on the FZG test rig, using type C carburized gears and the different lubricants under evaluation. The operating temperatures of the oil and of the FZG gearbox wall were measured for different values of the input torque and speed and lubricant samples were periodically collected and analysed by direct reading ferrography. At the end of the tests, the gear mass loss and the oil viscosity were measured, the teeth flanks were inspected, looking for typical surface failure mechanisms, and the tooth flank surface roughness was measured. An energetic model of the FZG test gearbox, which took into account the power loss mechanisms inside the gearbox and the heat flow mechanisms from the gearbox to the surrounding environment, was used to calculate the friction losses between the gear teeth, knowing the oil, gearbox wall, and room temperatures, in steady-state conditions. Using this model, it was possible to analyse the influence of lubricant formulation on the average friction coefficient between gear teeth. The results obtained showed that one of the biodegradable, low-toxicity, ester-based gear oils generated significantly lower mass loss than all the other lubricants, presenting almost no degradation, even when operating at very high temperature for long periods. These bio-lubricants generated friction coefficients between gear teeth up to 27 per cent smaller than the commercial mineral oil, promoted significant reductions of the power loss inside the FZG gearbox, increasing the overall efficiency up to 0.25 per cent.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10