Lubes and seals: Running relay races

摘要

On reversing gantries and other systems, lubrication and seals are subject to oscillating motion. For example, on some pumps, the rotation of one part is converted to oscillating plunger motion to draw, pressurize, and deliver fluid. How does lubrication behave in these situations? Optical interferom-etry and numerical analysis show that oil film thickness under reciprocation is thinner than that under unidirectional motion. Why? A starved condition is induced by cavitation (generated during previous contact-region passes) that briefly persists after reversal.