Visual inspection for open gear guide

[jarimasen]

Hello all,

I am trying to find a guide for visual inspection on wear for open gears (girth gear and pinion). Specifically for ballmills or kilns. I saw the AGMA 1010 E95, but I am trying to find measurement points and how to take them.

In my country we do these measurements (backlash, contact and alignment), but I want to know if there is a better way. I have seen on youtube videos that sometimes the use lead wire to measure contact on open gear. However there are various questions, like how thick should the wire be? can I use lead/tin wire for soldering (pure lead is not very common) or does it have to be specifically for this application (because of precision measurements of some sort)?

Anyway if somebody has a guide I could follow or a book I can buy I would greatly appreciate it

JM

 

[3DDave]

It seems like that is a way to measure backlash - any soft lead that won't damage the tooth surface should be OK to try. You are measuring the thickness at the minimum point. Pure gold wire should also work, but lead is less expensive. If you've ever put a copper coin on a railroad track you know that if the material isn't fully soft it can still register a thickness even if there is no nominal gap - much less likely in lead on a gear mesh. Obviously the wire needs to be thicker than the expected backlash; I would not go farther than 3X but up to 5X should be problem free.

Watch your fingers. If the input gear can be hand-cranked, that would be great.

What may be more critical is the tooth form, but I don't know any cheap ways to do that. My experience is the most wear in a mesh will be on either side of the pitchline due to the sliding contact for the typical involute gear. On the pitch line you may see pitting from contact loads creating a fatigue failure.

 

[TugboatEng]

We use lead to measure the rod bearing wear on EMD engines, it gets smashed between the piston and head. It's plenty malleable.

 

[mfgenggear]

jarimasen

I did not reply immediately because I had to keep an open mind. but I have come to the conclusion that this will not be a satisfactory method of inspection. the gear teeth mesh back lash would have to be rocked.
I believe the best test would be a contact pattern test. and a review how contact pattern looks.

 

[jarimasen]

Thanks for your responses,

3DDave, What do you mean by tooth form and how do you measure it? Is it the same as contact pattern test? How do you measure this last one?



JM

 

[3DDave]

Google is your friend for supplying more information about that than I can.