Involute Tooth profile formulas

[Pjohnny]

Hi, I’am a new user.
I’m trying to draw a tooth gear but I don’t have formulas and data table to do this because ( I think ) it is a Stub tooth gear.
These are the straight spline specification:
- Tooth profile Involute
- Module 0.7
- Numb. Of teeth 26
- Pressure angle 45°
- Pitch diam. 18.2 mm
- Outside diam. 18.4 mm
- Root diam. 17.3 mm

Could anybody help me please ?

Thanks.

 

[hugou]

Do you have access to AutoCAD?
If you do, a useful and free little utility is called truegear.lsp
To run it type appload in your command line and then select truegear.lsp
Then tpye tooth to start the application.
It generates the involute as lots of little facets but I tend to trace over these with a spline when I import the .dxf into a proper CAD package like Pro/E and then pattern the tooth.

 

[Pjohnny]

thank you very much hugou,
Yes we have Mechanical and Catia.
I'll try that lisp program and then i'll give you a feedback.

 

[Pjohnny]

Great ! It works fine.
It seems the tooth profile is right.
Anyway, where could I get formulas or data table about Stub gear tooth ?

 

[dinjin]

I have not seen a metric stub tooth system. In the inch system the addendum is .80/DP and the dedendum is 1.00/DP for the standard stub system gearing.

You are talking about a module spline and the rules are different for splines than for gears and the profile shift is also often adopted in the individual module spline standard and then different for the number of teeth. I do not have the .7Module
spline standard now but I do know that they exist. Maybe someone else has it and can help you.