Optimal Tooth Modifications in Face Hobbed Spiral Bevel Gears to Reduce the Influence of Misalignments on Elastohydrodynamic Lubrication

Abstract

In this study, an optimization methodology is proposed to systematically define the optimal tooth modifications introduced by headcutter geometry and machinetool settings to minimize the influence of misalignments on the elastohydrodynamic (EHD) lubrication characteristics in facehobbed spiral bevel gears. The goal is to simultaneously maximize the EHD loadcarrying capacity of the oil film and to minimize power losses in the oil film when different misalignments are inherent in the gear pair. The proposed optimization procedure relies heavily on the EHD lubrication analysis developed in this paper. The core algorithm of the proposed nonlinear programming procedure is based on a direct search method. Effectiveness of this optimization was demonstrated on a facehobbed spiral bevel gear example. A drastic increase in the EHD loadcarrying capacity of the oil film and a reduction in the power losses in the oil film were obtained.