Prediction of Fatigue Life of Spiral Teeth through Analysis of Finite Elements and Experimental Checks

During initial gearbox design, the present trend is to use gears with little diametral pitch and less valuable steel; first for noise problems and then for economical and political reasons connected with the strategical availability of some alloy materials.

These reasons brought the teeth limit of fatigue to minimum required values for gearbox endurance and new methods of calculation were developed more and more sophisticated than old ones.

The paper describes the theoretical approach to the stress calculation and discusses the possibility of comparing the calculated data with the fatigue tests and the related actual performances of the gears in the case of different heat treating or surface finishing conditions.