Mass Flux Distribution Measurements and Visualizations of a Fluid Sheet Generated by a Partially Immersed Dip-Lubricated Gear

Abstract

A simplified model of gearbox lubrication flow is investigated. A metric gear with module size 4 mm, tooth number 38, tip radius 80.25 mm and width 40 mm, is partially immersed and rotated between 0–12 1/s frequencies in room temperature distilled water. Flash and laser sheet visualizations of the global flow field and the boundary layer are presented. Resolved mass flow distributions in the fluid sheet above the water surface are obtained with in-situ liquid trapping (bucketing). The relation between the circumferential velocity and integrated mass flux of the fluid sheet is found to be linear above a critical speed, for which an analytical formula is given. Using dimensional analysis, we show that the relation between the mass flux and gear speed signifies a Reynolds-number independent behavior of the boundary layer around the immersed part of the gear.