topic Re: Constraining a planetary roller in Inventor Forum

Constraining a planetary roller

Anonymous — Mon, 24 Sep 2018 21:12:44 GMT

Hello guys,

thanks for your help in my previous posts.

Currently im trying to constrain a planetary roller but dont quite make it yet.. In the end it should all be fixated and able to turn around.

What I did so far was to constrain my Cylinder to the XY-Area and the Z-Axis so it cant move but turn around.

I did the same for the center spindle. Flush it on the cylinder and then use the center line of the spindle and bind it to the z-axis as well. Its also able to turn around.

Now the last thing I have to manage are those little spindles inbetween the center spindle and the cylinder. So far I used a flush for them onto the cylinder. They are not moveable in Z-Axis but in X-Axis. I really have no clue how to constrain the movement for the X-Axis..

Do you have any Ideas? I will provide some screenshots for you people

kelly.young has embedded your image for clarity.

Re: Constraining a planetary roller

TheCADWhisperer — Mon, 24 Sep 2018 13:28:03 GMT

Attach your assembly here and end all doubt.

Re: Constraining a planetary roller

Anonymous — Tue, 25 Sep 2018 08:03:39 GMT

Ohhh I didn't think about attaching the assembly !! thanks 🙂

EDIT: It seems like i can't attach more than 3 data but I have 3 parts for the assembly.

Re: Constraining a planetary roller

WHolzwarth — Tue, 25 Sep 2018 08:24:30 GMT

You can zip them into a single file

Re: Constraining a planetary roller

WHolzwarth — Tue, 25 Sep 2018 09:00:30 GMT

Here's a general setup, without the missing outer Walzenzylinder.ipt

Because of lazyness I only used 5 planets; you can drive the system with Drive angle

New 2016 files attached.

Re: Constraining a planetary roller

Anonymous — Wed, 26 Sep 2018 09:02:41 GMT

Thanks for the assembly. But theres one problem with this and I didnt mention this in my initial post.

The X and Y and Z position MUST remain the same. You changed the positions of them 😕

Where can I find this "Drive Angle"? Is this a function in Inventor?

Heres a zip of ALL the parts of the assembly ! 🙂

Re: Constraining a planetary roller

Cris-Ideas — Wed, 26 Sep 2018 14:53:20 GMT

hi,

Here you have it, but unfortunately in 2017.

Cris.

Re: Constraining a planetary roller

WHolzwarth — Thu, 27 Sep 2018 07:07:02 GMT

Good animation, Cris.

But planetary gears have several methods for fixing the grounded part. You have fixed the axes of the parts named Standardspindel.ipt. The outer part Walzenzylinder.ipt is rotating in your setup.

But I think, the outer part is fixed in this special case, and the six spindles should rotate and change the position of their axes.

Look here:

https://de.wikipedia.org/wiki/Planetwalzenextruder#/media/File:ENTEX-Verfahrensteilschnitt_m._Temp.-zonen_de.jpg

Re: Constraining a planetary roller

Cris-Ideas — Thu, 27 Sep 2018 07:15:18 GMT

@WHolzwarth

But I did this intentionally as @Anonymous wrote "they are not to move" regarding planetary gears.

So I went the easy way.

What is interesting is that if flexibility was working properly you theoretically would be able to use assembly constrained like this (the easy way) as a flexible component and you would be able to set up any of planetary gear setups you wish, only with this single component.

Cris.

Re: Constraining a planetary roller

WHolzwarth — Thu, 27 Sep 2018 19:21:44 GMT

Here's a 2017 fileset with grounded outer ring.

Movement is not really smooth. I don't know, why.

Re: Constraining a planetary roller

TheCADWhisperer — Thu, 27 Sep 2018 19:25:37 GMT

@WHolzwarth wrote:
...Movement is not really smooth. I don't know, why.

Walter, have you given it a try in Dynamic Simulation with Rolling Cylinder on/in Cylinder Joints yet?

I haven't experimented with this one since the OP is on 2016.

Re: Constraining a planetary roller

WHolzwarth — Thu, 27 Sep 2018 20:04:59 GMT

I've just tried it, Jeffrey. I think, you're aware of the problem.

DS has some difficulties, when parts are not constrained with real geometries. I could place pitch surfaces for the members, but that's not enough. I think, it will be running in DS after adding a 5-place guiding part for the planets.

Additionally angular startup alignment will be needed.

Re: Constraining a planetary roller

Cris-Ideas — Fri, 28 Sep 2018 07:09:27 GMT

Hi,

I have experimented a bit with this assembly to find why this drive is not smooth in some cases.

I do not have any hard proof yet but already suspect this has something to do with order of constrains and order of parts in the assembly.

Interesting case, I will definitely give it more investigation.

Cris.

Re: Constraining a planetary roller

WHolzwarth — Fri, 28 Sep 2018 07:59:51 GMT

Meanwhile I made a separate attempt with a guiding part (cyan) in DS. Constraining can be done there very clean and straightforward. Movement is fun.

I only included two planets, rest is business as usual. 2017 dataset; I regret.