Optimization of Face-Hobbed Spiral Bevel Gears to Improve EHD Lubrication

In this study, an optimization methodology is presented to systematically define optimal tooth modifications introduced by head-cutter geometry and machine tool settings to simultaneously maximize the EHD load carrying capacity of the oil film and to minimize power losses in the oil film of facehobbed spiral bevel gears. The presented optimization procedure relies heavily on the EHD lubrication analysis developed by the author of this paper. The objective function and the constraints are not available analytically, but they are computable, i.e., they exist numerically through the EHD lubrication analysis. For this reason, the core algorithm of the applied nonlinear programming procedure is based on a direct search method. Effectiveness of this optimization was demonstrated on a face-hobbed spiral bevel gear example. Drastic increase in the EHD load carrying capacity of the oil film of 252% and reduction in the power losses in the oil film of 61% were obtained.