Experimental Investigation of Lubricant Extraction from a Micropocket

Abstract

This article presents the results of experimental investigations of lubricant flow out of a micropocket in a conformal contact due to surface shear. A test rig was designed and developed to perform a micropocket flow under boundary and starved lubrication conditions. The test rig consists of a laser-machined circular micropocket on a flat specimen operating against a rotating glass disk under an applied load. Silicone oil was used as the test fluid. Optical microvideography was used to investigate lubricant extraction from micropockets. A high-speed camera was used to observe the lubricant extraction phenomena from micropockets under various operating conditions. Microparticle image velocimetry was also implemented to quantify and analyze lubricant flow from a micropocket. The following results were obtained: (1) the role of a micropocket by comparing the lubrication mechanism of a contact with and without a micropocket; (2) the effects of load, speed, and micropocket geometry on lubricant extraction; and (3) the detail of the micropocket flow during the extraction using microparticle image velocimetry (μ-PIV).