Question on gear failure

[rob768]

Hello All,

i'm examining a failed gear (pinion-wheel, straight teeth) in which the pinion lost a few tooth due to fatigue, starting from one side of the teeth. There is also a pattern screaming misalignment, but this pattern is present on both flanks, and in both cases on the side of the pinion. Normal misalignment would cause these pattern to be present on opposite sides. Am I wrong in assuming shaft bending (or the box deforming) causing some sort of deformation (and thus a "dynamic misalignment") under load?

 

[mfgenggear]

Hi Rob

there a lot factors why this gear failed.
the bearing pattern is way off, so some of the causes.
misalignment of gear shafts
gross lead error
in correct backlash
gross Pitch Diameter runout
or all of the above.

start with a fish chart and analyze each gear attribute and shaft alignment and center distance.
it appears due to the errors it was end loading and cause excessive force on the gear teeth.
Complete inspection of all the details and of the housing.

 

[Tmoose]

"this pattern is present on both flanks,"

like this ?

https://khkgears.net/new/images/mou...or-tooth-contact-due-to-shaft-angle-error.jpg