WITHDRAWN: Numerical Visualization of Grease Flow in a Gearbox

Abstract

Gearbox lubrication plays a decisive role in both load capacity and efficiency. It is necessary for the formation of a lubricant film in tribological contacts, and for heat dissipation. Grease lubrication is often applied to gearboxes at a low operating speed and means that, for example, less effort is required in sealing design compared to oil lubrication. Over the years, the computational fluid dynamics (CFD) method has frequently been applied to support the lubrication-related design of gearboxes. However, very few studies have focused on grease lubrication. Whereas oil can generally be considered as Newtonian fluid, grease displays complex non-Newtonian flow behavior. In this study, the grease lubrication of a single-stage test gearbox is investigated by means of a finite-volume based CFD model. The numerical results on the grease flow show good accordance with high-speed camera recordings, and clearly display the lubrication mechanisms of “channeling” and “circulating”. These first results on grease flow simulation in gearboxes offer a starting point for further numerical studies.