Early results from testing conducted have raised questionsconcerning the role of gear action with the appearance ofmicropitting as well as surface fatigue (macropitting). Comparisonsbetween similar gear sets with the same loads, speeds, andlubrication but operated either as speed increasers or as speedreducers have yielded strikingly different propensities for wear.Further, these observations are not limited to lubrication basedfailures such as micropitting, but, so far, have applied totraditional surface fatigue failures (macropitting) as well.Findings point to an increase in the presence of micropitting ongearing operated as speed reducers. All components are operating atthe same speed and load, yet wear is greatly reduced for the drivencomponents. Perhaps more intriguing is that to date allmacropitting failures have occurred to the driving pinions of gearsets operated as speed reducers. While the number of samples isdecidedly small, the length of life for these components is muchless than would be anticipated under smooth load circumstances. Theother gear sets (operated as speed increasers) do not show anyfatigue wear. In addition to how gear action affects micropittingin gearing is the question of how the gear action affects fatiguelife. Current gear rating standards are based upon statisticalanalysis of real-world experience and mathematicalstress-versus-cycle calculations. If gear action affects howgearing fails in fatigue, there may be significant ramifications inthe industry. However, before any such conclusion may be made,additional testing is necessary.
- Edition:
- 09
- Published:
- 09/01/2009
- Number of Pages:
- 30
- File Size:
- 1 file , 2 MB
Reviews
There are no reviews yet.