The Reliability Evaluation of Transmission Gears
Pitting fatigue of gear teeth, if allowed to progress through continued operation, will result in tooth breakage and loss of drive. Laboratory test gears were run to determine their probability of failure under this mode. It was found that the dispersion or scatter of life values depends upon the gear surface contact stress; thus, there is less scatter at higher stress and, conversely, more scatter at lower stress. A cumulative damage method of evaluating transmission duty cycles is presented, with particular application to gear pitting fatigue, in a form adaptable to digital computer calculation.