Helical Pinion Gear

[187lockdown]

Hi All,

After some assistance with modeling helical pinion gear profiles within NX6. Has anyone got any suggestions on how to model this profile? Should I be using law curves to achieve such a profile?

Also goes anyone know of any gear generators website for NX?

Thanks in advance.

 

[smermet]

Hi 187lockdown,

See a proposition on attached file (native NX4 4.0.4.2 MP09 + parasolid)

Method :
1° - 2 skecthes on bottom & top section profil.
2° - helix beteen the 2 sketches, with expressions to be associated with sketches.
3° - Swept.

Say me, if this solution, is agree with your expectations
Best regards

 

[hudson888]

The attached file is the construct for such a gear. How the involute and helix angle are calculated are not shown but the modelling method of creating a sweep that best respects the desired helix angle.

Unfortunately there is a lot of maths to the construction of good gear design which I'm simply not across. It would be great though if it could be constructed into a series of accurate gear designs that were parametric or perhaps even as part families.

Best Regards

Hudson

www.jamb.com.au

Nil Desperandum illegitimi non carborundum

 

[smermet]

Hi,

If you can open the native NX4, you can see the way that is used.

Helix, is parameted on external Ø of gear, and heigh of gear.
Helix Radius = External gear radius.
Helix Pitch = 360°/(angle between top and bottom tooth sections)x heigh of gear.
Nbre of turn = Heigh of gear / pitch.

This explanation seems you correct?

Best regards.
Seb.

 

[hudson888]

smermet,

I would have used a sweep with a simple angle law function rather than a helical curve to drive the shape control of the twist. I think that it may just be slightly more accurate. Nor is it always easy to find proper involute tooth forms when you need them.

Best Regards

Hudson

www.jamb.com.au

Nil Desperandum illegitimi non carborundum

 

[smermet]

Hi hudson888,
It seems to be a good way...
Are you able to materialize this on a file that you will attached on your response?
Thanks

 

[Hitchcock]

Here is a decent metric spur gear I've created. It's straight, but you can sweep the tooth profile through a helical guide to get what you need. Modify the general gear variables using the expression editor.

Hitchcock

 

[smermet]

Hi Hitchcock,
I do not understand?
regardless if the profile of the teeth is correct or not ...

 

[Hitchcock]

Hello,
My 1 October post was meant to address the first post in this thread.
"
After some assistance with modeling helical pinion gear profiles within NX6. Has anyone got any suggestions on how to model this profile? Should I be using law curves to achieve such a profile?

Also goes anyone know of any gear generators website for NX?
"
The file I had attached is just a basic parametric spur gear profile (metric) from which the involute curve within can be extracted. This may be useful when following the other procedures above to generate the helical version.

Hitchcock.