CFD Modeling of Lubrication System in Agricultural Power Split Transmission

A complete lubrication circuit study of a CVT gearbox is presented in this paper. The study of the lubrication in gearboxes is an important issue in off-road machines design because reliability depends mostly from lubrication performance, as well as machine lifetime and overall energy efficiency of the transmission. A CFD Monophase model were generated to study the flow of lubricant directed to various gearbox components at different temperature and rotational speed. As rotation of components generates pumping effects and the moving parts are surrounded by atmospheric pressure air, aeration is very likely to happen. Applicability and limits of the monophase model will be discussed then, in case of applicability, the behavior of Lubrication Circuits is mapped, giving the opportunity to assess the performance of lubrication system, identifying the critical operating conditions and improve design process through virtual optimization. In case of Air Inclusion some further development will be proven to be necessary, such as Multiphase Flow study.