Optimal Design of Compact Spur Gear Sets

Abstract

In a recent article [3], Savage, Coy, and Townsend presented a method for the optimal design of compact standard spur gear sets. They gave figures and design rules based on a design model that considered scoring, pitting, bending fatigue, and involute interference. The work reported here expands the Savage, Coy, and Townsend model to include the AGMA geometry and dynamic factors. The extension was possible, in part, due to the appearance of an article by Mitchiner and Mabie [7] which provided a computationally simple means to determine geometry factors. A design strategy is presented and illustrated by examples. The method is available from the second author in the form of a short Fortran program. The code is applicable to spur gear tooth systems where the addenda and dedenda are inversely proportional to diametral pitch (e.g., the standard tooth system). Other developments of the paper include a new derivation of the expression for pinion roll angles and an observation regarding the method of Mitchiner and Mabie [7] which allows a general form to be used in the determination of the geometry factor for any point during the contact cycle.