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i have a doubts as im monitoring this gear box i have the follwing data
                  400/800 HP   

                  450/900 RPM INPUT
                   20/40 RPM OUTPUT
                   22:1 REDUCTION
is there a way of finding the teeth number on each gear?
i have data results (FFT) and i dont want to interpret it before getting the right input
any help would be very much apreciated

RE: Gears

Only with some detective work. The problem is that the 22 to 1 or 22.5 to 1 ratio (which is it?) is probably the result of a double reduction, if not a worm drive, so there are a few options.

1) are the input and output shafts parallel? If so it's probably not a worm drive.

2) How many shafts are there internally? Look at the casing to see how many bearings there are.

Assuming that it is a double reduction then do a cepstral analysis to identify the likely number of teeth on each gear, then fiddle around with the internal configuration until you get the right gear ratio.

It might be easier to take the inspection cover off and count the teeth.


Greg Locock

RE: Gears

A quick call to the service department of the manufacturer may also yield good results.  Also, they should give you the type of bearings.


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