Friction and wear characteristics of linear contact sliding friction pairs under oil-air lubrication

Oil-air lubrication has been extensively used in mechanical equipment fields. The study aimed to evaluate the tribological behavior of linear contact sliding friction pairs under oil-air lubrication. An oil-air lubrication equipment was developed, and linear contact sliding friction under oil-air lubrication test was carried out on a reciprocating wear test device. Microscopic feature and composition distribution of the wear scars were conducted using scanning electron microscopy, optical white-light interferometer, energy-dispersive X-ray spectroscopy and Raman spectrometer. The influence rule of oil supply, oil pressure, airspeed, air pressure and oil temperature on the tribological behavior of linear contact sliding friction pairs was obtained. Experimental results demonstrate that the friction coefficient curves of different parameters are composed of four stages, namely, the initial stage, the recede stage, the ascent stage and the stable stage. The relationship between oil-air lubrication test parameters and wear was discussed. The wear mechanisms of linear contact sliding friction pairs under oil-air lubrication are delamination wear, abrasive wear and oxidation wear.