Effect of air supply speed on point contact sliding wear characteristics under oil‐air lubrication conditions

Abstract

An oil‐air lubrication system is driven by high‐speed air. Oil is transported to the contact portion in the form of fine oil droplets to form a lubrication film, thereby improving lubrication performance among matching pairs. A test for point contact sliding friction and wear was conducted under oil‐air lubrication conditions. Oil‐phase and pressure distributions near the contact zone were investigated through numerical simulation. This study aims to explore the effect of air velocity on sliding wear characteristics of a point contact. Results show that point contact sliding wear is considerably affected by air supply speed. The lubrication performance between friction pairs is optimal under appropriate air supply speed, which can enable the oil‐air pressure and oil‐phase volume fraction near the point contact area to obtain appropriate values that are useful to the spread of fine oil droplets. This process ensures that the sliding friction coefficient and specific wear rate can be reduced. The friction coefficient decreases to approximately 0.027, and the specific wear rate is 1.06 × 10−5 mm3/N·m. Under oil‐air lubrication, microfurrows appear on the worn surfaces of materials with the change in air supply speed. The shape of debris is mainly a flake or block with a few long strip abrasives. The wear mechanism is abrasive.