Herical Gear Root Stress Prediction for Automotive Transmissions

Demand for lighter and smaller automotive transmissions is accelerating the need to accurately predict the helical gear root stress. In an effort to identify the maximum root stress of a in-mesh tooth, the load distribution along the contact line is investigated with 3-dimensional finite element models. Resultant data from the FEM analysis was utilized to derive a simple formula that aims to serve the same purpose. This formula takes into consideration three new factors on stress compensation, effective facewidth and stress concentration in addition to the tooth form commonly associated in stress calculations.