How do you do a planetary gear arrangement?

[Anonymous]

I am looking to generate a planetary gear arragnement similar to the picture attached. I am looking for a 6:1 ratio between the outer sput gear and the inner sun gear.  Can someone help?

Thanks

[JDMather]

Something like this?

http://forums.autodesk.com/t5/Autodesk-Inventor/Epicyclic-Gear-Train-Planetary-Gears/m-p/3222816/hig...

[Anonymous]

Yes Something like that, With the sun gear operating at roughly 6:1 ratio of the Outer Spur gear with 3 no. planetary gears orbiting? Can I acheive this on the gear generator?

[JDMather]

Yes, what I do is use the Gear Generator to create the ring, sun and planets and then add my own constraints to control the motion.

It takes a couple of steps (no sun and planet easy button).

[Anonymous]

I appreciate its not easy to do, thats why Im asking for help

[JDMather]

Can you attach the ring gear, the sun and one planet here (you will have to create an extra gear using the Gear Generator - but you can simply delete that extra planet - we will use 3 instances of the one planet.

If you want someone to create the gears for you - you will need to provide some specifications.

Is this a student project?

[Anonymous]

I dont have the gear information, I have the ratio required of 6:1 and the diameters of the outer spur gear (550mmm) and the inner sun gear (75mm) thickness of both is 10mm. That is all the information I have im afraid.

It is a student project yes

Regards

[JDMather]

That is a start - now the quesion is  - what are those diameters (we would usually specify the Pitch Diameters).
Should be able to work something up even with limited information that is representative - even if not exactly what you need.  This should at least give you the information to see the How it is done.

Which gear is the input, held and output for this design?  (the gear ratio output and direction depends on which one (or three in the case of the planets carrier) are held)

[Anonymous]

I would say if I go with 550mm outer pitch diameter, the sun gear @ 92mm dia and planetary gears at 229mm. I want to be able to drive it both ways but for the purpose if this exercise I would like the outer spur gears to drive the inner sun gear at 6:1 speed

I do actually have a no. of teeth for the sun gear of approx 20-22 if this helps?

Regards

[JDMather]

It will be some time before I can get back to this - hopefully someone else will jump in here.

In the meantime you might experiment with the Gear Generator in creating a ring and planet and a sun and planet (of course that isn't the terms the Gear Generator will use - but convenient for this discussion).

Somewhere  I have a sun and planets input/hold/output ratio/direction table.  (I'll try to post it later - I imagine these days a search on the internet should turn up a similar table - mine is from before there was an internet.)