Internal spur gear not linking/rotating but sliding!

[tarkoger]

Dear professionals!

I've browsed internet, viewed tutorials, read the forums for several days and I cannot figure out how can internal gear (smaller one) be constrained in a way that if motor shaft rotates - gears still link to each other.

Current situation:

A: if I drag motor shaft - internal gear planes remain parallel to original planes - it's just sliding not rotating inside external gear - motion rotational constraint isn't working!

B: and if I drag internal gear, it somehow links to external gear, but it's unpredictable. 

Thank you in advance!

Software: Inventor 2013. Files attached.

[mdavis22569]

I couldn't get all the parts in ...but I worked with what I could to get the gear to do what you asked.

I had to break up the Gear assembly to get it to move due to all the constraints ...

This isn't perfect, again due to not having all the parts, but it does move like you asked

[mdavis22569]

I also grounded the outside gear from being able to move.  Having the original assembly flexible allowed the gear to be moved and not grounded ...

[tarkoger]

Thank you for the reply Michael.

Unfortunately I cannot open the files. Probably because you are using newer version.

But if it wasn't very long process maybe I could try it. How did you break up the Gear assembly?

I've seen many engineers designing gears separately (Component - No model and again with the same parameters No model - Compnent) then adding constraints between them later - is it a better way? Then It'd be easier to ground the external gear and mark internal as flexible?

Does the Grounding have same effect for exernal(outside) gear if just mate it with the original planes - both ways there'd be no DOF?

Looking forward to your answer,

Tarko Koger 

[mdavis22569]

what version are you in

[tarkoger]

Inventor Professional 2013

[mdavis22569]

I promoted the 2 gears into the Wing IAM ... leaving the Gear assembly file empty. I deleted it then..

I then moved the outer gear to the top of the Browser tree as you can see in the png 

[tarkoger]

Hi,

Sorry for the delay but I tried several times again, still the same problem. I attached very simple assembly again. Maybe you see where is the important constraint missing.

Maybe Directed Angle constraint be the issue but I cannot figure it out. Examples refer to:  https://www.youtube.com/watch?v=KqZnpgq6vBs (4:20) and https://www.youtube.com/watch?v=j6n0MaIqrZo (13:10) Could that be the case?

I really like you help me to solve it and get it work. It's almost despressing already:) 

[mdavis22569]

what version are you in ... 

I have 2013-2015

[tarkoger]

I'm using 2013

[tarkoger]

But maybe you can send a screenshot of all the expanded constraints you placed (on the assembly I couldn't open). It would be helpful trying to figure out where my error might comes.

[mdavis22569]

Here is a quick fix ...so both will move in what you had ..it's in 2013. 

I'll be back in a bit, going to party, I'll finish it when I get back. Sorry I couldn't do more at this time. 

[tarkoger]

Hi,

I tried it again in Inventor 2015 (files attached) but still the same issue.

1. If I Drive the motor shaft link.ipt rotational joint with external gear (Grounded) from the center (as sopposed to when fixed to motor), spur gears do not link with its teeth. Like Rotational motion constraint is ignored.

2. And when I Drive Angle constrain of the internal spur gear - it simply rotates over its central axis - still neither linking to teeth nor rotating over Origin z-axis.

Only if I pull the internal gear with mouse - gear teeth link but it moves unexpected!

I'd be grateful if you could help to solve the error. Big thanks in advance!

[tarkoger]

Is it possible to save simulation video in assembly mode - then it'd be easy to show what doesn't function as desired?

[WHolzwarth]

Hmm. I think, it never worked without any problem.

Here's my attempt (2 ways, 2015 IAM, part data as before)

1. Switch to Posrep Hauptansicht (Main). You can move by constraint Drive

2. Switch to Posrep By Mouse. You can move the small gear by mouse, but as mentioned before, no good movement by gripping the motor shaft link is possible.

Walter.

[rdyson]

I didn't read the thread thoroughly so I may be off here but this iam will let you drive the "drive" constraint or mouse drag the shaft in the "mouse" pos rep and the gears will stay in mesh.

[WHolzwarth]

Interesting, Ray.

But mouse movement still has issues. You can't grab the small gear for that.

[rdyson]

HHHMMMMMM?
Didn't notice that Walter! I wonder if it should have worked?

[WHolzwarth]

Perhaps I'm having language problems, Ray.

But with Mouse PosRep, neither my setup nor yours was satisfying.

[JDMather]

You would have more predictable results in the Dynamic Simulation Environment.

If you have Inventor Professional, open the attached assembly.

Go to Environments>Dynamic Simulation.

Drag with mouse or play the simulation.