A condition in which mating teeth touch mainly at one end of the face instead of across it, so contact and bending stresses there run far above design. It comes from bore misalignment, shaft and housing deflection, helix errors or thermal distortion, and it shows as pitting, scuffing or breakage concentrated at one end. Crowning, helix correction and better alignment fix it.
All the pitting's on the coupling end of the face, classic edge loading, check the housing bores for parallel before we order gears.
Also heard as
- end loading
- end contact
Related terms
Crowning
A slight barrel shape along the tooth face so contact stays centered despite misalignment and shaft deflection.
Helix deviation
How far a tooth's actual path across the face width departs from the intended helix, including crowning.
Face load factor
A rating factor that raises calculated stress to cover uneven load distribution across the face width.
Contact pattern
The imprint left on gear teeth by marking compound after running, showing where and how the teeth touch.