Reply to "Gearbox Vibration"

Kevin,

Input speed = 3600rpm = 60Hz
Output speed = 1175rpm = 19.58Hz

Unfortunately you will need at least one more parameter to determine the teeth e. g.: one gear's teeth OR the gear mesh frequency.

The gearmesh frequency should be a characteristic dominant peak highly visible in your FFT. If you manage to find it, zoom in and look for side band frequencies spaced at either 60Hz or 19.58Hz, the side band frequency and pattern should lead you in the correct direction with regard to which gear is defective etc.

I think (from some calculation in an Excel spreadsheet) your gearmesh frequency should be approximatelly

960Hz which will give you an input gear with 16 teeth and an output gear with 49 teeth.
but more likely

1920Hz which will give you an input gear with 32 teeth and an output gear with 98 teeth.

In analysing the gearbox high vibration I suggest you pay particular attention to the gearmesh frequency and its sidebands as well as the timewaveform for signs of impacting or modulation etc.

Have fun.

Stefan