A methodology for predicting and optimizing the lubrication of an off-road machine transmission

Abstract

This article presents an analysis method based on lumped-parameters (LP) and computational fluid dynamics (CFD) to evaluate the behavior and calibrate the lubrication (LUB) circuit in an agricultural dual-clutch transmission. Gearbox LUB is crucial because it affects reliability, life, and transmission efficiency. The transmission’s hydraulic circuit consists of the higher pressure power transmission control and actuation circuit and the low pressure LUB circuit. The former was analyzed with LP approach, instead the latter was modeled with CFD approach due to its geometric complexity. The results will be contextualized by commenting on the advantages and limitations of LP and CFD analysis, finally outlining a mixed analysis methodology. The simulations are solved for different engine speed. The results are used to calibrate a comprehensive LP model (model) and to optimize the LUB circuit by adjusting some critical design parameters. As an experimental approach, simplified tests are usually performed ignoring the action of the centrifugal force, which has a great impact on the flow regime inside the LUB ducts. This work aims to develop a methodology for analyzing LUB in all parts of the gearbox, which can help designers test various combinations within industrial timeframes and obtain reliable and the most efficient configuration.