Hi JG ,

I'm afraid that you'll need substantial technical education to do this properly .

The shape and size of the contact zone between worm and gear is determined by the specific geometry of both parts and on the loading .

The common load line between both is at a compound angle determined by the specific geometry of both parts .

I suggest that you study :

Gear theory .

Contact stress theory and high load contact zone surface deformations . A lot of this is covered in ball bearing theory .

Auxilliary plane projection in traditional drawing and then in CAD .

This is really too complex a subject for this site and whilst I'd be happy to answer a few questions I don't think that me giving a long detailed general explanation on here would be appropriate .

I wish you every sucess in any case ,

Michael Williams .

Aw, go on, try us. If we're too dumb to understand so be it, but if we don't try we'll never know.

Andrew

Use a real worm and wheel and some engineer's blue to find out what teh real contact patch looks like? Or is that too empirical?

Neil

Andrew, which bit of the question/answer would you think we should start with – tribology, metallurgy, material science, transmission/gear design or advanced simulation and modelling?

As Gary points out, the answer to this question is to seek help from his Catia reseller who will no doubt accommodate him with the required training to use these tools confidently. I must also admit to being curious as to how he has managed to get access to that level of software without having the associated support available.

Mark

You might find the NSK (RHP Bearings) web site interesting if you want to know more about bearings without getting too technical at first.

http://www.nsk.com/rd/technology.html

Mark

Andrew, you might also look at the SKF site along with the INA offerings. SKF are particularly good for spindles etc. depending on how industrial you want to go!

Mark