This paper describes the work performed to reduce 1st order gear mesh vibration which was the root cause of
an excessive gear“whine”. |t includes a discussion for introduction of an unmodified involute profile (except
for a short tip relief to smooth the tooth entry and exit into the mesh), inspection charts, significance of a
statistical sample size for validation, vibration measurements, and correlation of tooth profiles to vibration
results. While many articles on gear noise reduction focus on introducing profile modifications, this paper
describes one helical gear application where an improvement was achieved by the elimination of profile
modification.