Effect of behavior of oil–air lubrication flow on characteristic of point contact sliding wear

Purpose This paper aims to investigate the influence of oil–air lubrication flow behavior on point contact sliding wear characteristics. Design/methodology/approach Oil–air lubrication equations between point contact counterparts were established on the basis of volume of fluid model. The effects of oil supply and injection azimuth on oil-phase volume fraction and its pressure distribution were simulated with commercial software Fluent. Characteristics of point contact sliding wear were then tested with an MFT-3000 friction tester under oil–air lubrication condition. The influence of flow behavior on wear characteristic was investigated combined with numerical and experimental results. The wear mechanism was revealed using SEM, EDS and ferrography. Findings When air supply speed is constant, the oil-phase volume fraction increases with the increase in oil supply, which helps form continuous oil film and decrease the sliding wear evidently. The injection angle and distance considerably influence the oil–air flow behavior. When injecting at a certain distance and angle, the oil-phase volume fraction reaches its maximum, and the abrasion loss is minimal. Under the test conditions in this study, abrasive particles are mainly debris and a few spiral cuttings. The wear mechanism is abrasive wear. Originality/value The influence of the behavior of oil–air lubrication flow on the characteristic of point contact sliding wear is analyzed. This work provides guidance for the application of oil–air lubrication technology in point contact friction pairs.