Degradation analysis of gear oil SAE 90 used in load haul dumper machine

Lubricant degradation is the main cause for low performance of the machine such as heavy engineering machines, mining machinery etc. Lubricants are used for smooth running of gears and they also avoid friction and noise. Its performance is affected by high temperature and shearing, due to high temperature viscosity of oil changes and due to shearing its physical property changed or degraded. This paper analyses the failure behaviour of gear oil used in Load Haul Dumper (Model No: Eimco Elecon – 811MK). Gear oil degradation was measured by oil analysis in two sections: (i) fluid properties and (ii) contamination in the oil. Fluid properties were analysed by Viscometer, Rheometer whereas contamination analysis was done by Fourier Transform Infrared spectrometer (FTIR). All tests were performed carefully and their graphs were plotted. Results show that temperature and shearing were two of the several causes for degradation of oil. Viscosity analysis clearly presents that viscosity of oil exponentially decreases with temperature. Viscosity is also decreasing with shear rate at different temperatures. FTIR analysis confirmed that contamination is increasing with continuous use of oil. Temperature and oxidation are the main reasons for degradation. Different composition forming in used gear oil and those were confirmed by infrared spectroscopy absorption table.