Development of an Analysis Program to Predict Efficiency of Automotive Power Transmission and Its Applications 2018-01-0398

Prediction of power efficiency of gear boxes has become an increasingly important research topic since fuel economy requirements for passenger vehicles are more stringent, due to not only fuel cost but also environmental regulations. Under this circumstance, the automotive industry is dedicatedly focusing on developing a highly efficient gear box. Thus, the analysis of power efficiency of gear box should be performed to have a transmission that is highly efficient as much as possible at the beginning of design stage. In this study, a program is developed to analyze the efficiency of an entire gearbox, considering all components’ losses such as gear mesh, wet clutches, bearings, oil pump and so on. The analytical models are based on the formulations of each component power loss model which has been developed and published in many existing papers. The program includes power flow analysis of both a parallel gear-train and a planetary gear-train. The program is also implemented with the assumption that the components of power losses are independent of each other. The developed program is employed to estimate the power losses and efficiencies of several automobile gear boxes. The results are then validated by comparing with the experimental data.