Abstract
The fluid motion around mesh region might interfere or assist the lubricant delivery to the tooth surfaces for heat removal. For better cooling of gear teeth immediately after mesh, fluid motion was investigated experimentally. The matter of interest concerns rather high speed operation of about some tens of meter per second. Visualization was done in air with smoke, and also in water with transparent PMMA gears and tank in which plastic and metallic tracer particles were used. By several means of 3-D visualization, whole behavior of fluid movement was discovered; Some part travels before pitch point trapped in back lash space, some part is sucked into tooth spaces axially from the leading end opening and some part gets into the space from the mesh exit space with some axial velocity component. Afterwards movement of particles is discussed for practical lubrication from the exit region of meshing. Since the small particles are driven by drag force of fluid, the movement depends on the projection area of the particle and also on weight (inertia), the heavier the weight the smaller the driven effect. This revealed that the experiment in water corresponds to the actual condition when the lubricant forms misty, or the size of the particle is small enough. Additionally some hints for better delivery is proposed such as bigger oil drop is preferable when traveling in air.
