Determination of optimum gear ratios of a two-stage helical gearbox with second stage double gear sets

This paper introduces a study on the optimum calculation of the gear ratios of a two-stage helical gearbox with second stage double gear sets. In this study, for finding the optimum gear ratios of the gearbox, an optimization problem was conducted. In the optimization problem, the objective function was the acreage of the cross section of the gearbox. Besides, the effect of the input parameters including the total gearbox ratio, the wheel face width coefficient, the allowable contact stress and the output torque were considered. For investigation of the influence of these factors on the optimum gear ratios, an "experiment" was designed and a computer program was built for conducting the "experiment". Also, models for determination of the optimum gear ratios of the gearbox were proposed. By using these models, the gear ratios can be calculated accurately and simply.