How to Measure Gear Teeth and Pinions

[p v k Raju]

Hi
This is PVK Raju and I would like to know how to measure the Gear measurement
like span measurement and measurement with pin etc.
for example we have one of our part like pinion and gear data like Module and no of teeth effective dia and major dia etc based on above data how to collect the gear design data and how to measure the gear and pinion.

Please help me.

Thanks & regards,
PVK Raju

[Ninja]

Hello pvk Raju,

Are you looking for something like this: http://www.qtcgears.com/Q410/PDF/Q410P366.pdf

Or are you looking for something different?

[p v k Raju]

Hi Ninja
Thanks for your immediate response
I would like to know basic details how to measure the gear/pinion - like span measurement and measurement over pin method etc.I am not understanding what you have send. However I am very happy your immediate response.

I have the following information
Pinion
Outer dia 68mm
reference dia 6omm
Module 4
No of teeth 15
Pressure angle 20 deg.
Center distance of gear and pinion is 112mm
For the above data I would like inspect the Pinion by simple method like vernier caliper and Micrometer.-Teeth thickness Span measurement and Measurement over pin etc.

If you have any example please help me.

Thanks
PVK Raju

[Miner]

There is no simple way to measure gears. Gears have an extremely complex geometry and typically require equally complex measurement devices with which measure them. There are some measurements that might be taken on spur gears using verniers and micrometers, but I am highly dubious that the measurement system variation would be acceptable. Gear quality goes far beyond the simple measurements of pitch diameter or tooth thickness. Very subtle dimensional differences can cause objectionable noise and vibration when running at speed. It can also result in premature wear.

This is an example of a relatively simple gear inspection. I suspect that this is much more involved than you anticipated.

[somashekar]

Have a look at THIS and see if it comes to your help.
As Miner mentioned, it is complex and needs skill and good instruments

[Claes Gefvenberg]

As somashekar and Miner suggested, there is much more to measuring gears than first meets the eye: It is more like a form of art than pure measuring. However, I think that the document provided by somashekar is very good, and ought to give you a good start.

I would also suggest that you get in contact with the gear designers and learn from them. I did when I dealt with gears long ago, and it helped me immensely to learn about theory and intended function of the products from them.

/Claes

[p v k Raju]

Thanks to all
Giving your valuable inputs
Reason behind this quiry is one of our supplier made the penion as per our (drawing) requirement and the drawing does not show the gear design data but supplier has made as per their design data based on our inputs like reference dia and no of teeth pressure angle etc.and accordingly the supplier made the gear and submit the inspection report but we don't have the details for inspection. and how to accept the part?

Please help me

If you have any basic gear inspection material or suggest any relevant sites etc. very useful to me.


Thanks & Regards.

P V K Raju

[carol4832]

After reading through this thread I am interested in finding out what is the most accurate form of measurement technique and tools to be utilized when measuring an internal gear over pins.

1). Currently 2 gear wires rubber banded to master blocks equivalent to the stackup length is a method. ( I am not too convinced that this is a good way to obtain the measurement) too much variability in rubber bands; (flex, movement, etc.) to obtain a trustworthy measurement.

2). 2 gear wires with a telescoping micrometer; after indicatiing the telescoping micrometer is measured.

3). plug gauges?? I understand may be a viable option for more precise measurement. however who can manufacture these types of tools.

4). Gear Analyzers - Quite costly, however maybe necessary to get a truly accurate measurement.

5). Can a CMM be used? with accuracy levels high enough? does anyone have any recommendations on what can be used?