GENEVA Mechanism

[dbodar]

I want to make "GENEVA Mechanism" in Creo 2.0... so plz help me which type of constrain i use for that...????

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[jsarkar]

Welcome to this forum,

slot follower mechansim can be appliead definitely by predifing the motion curve and point. I am trying to explore the other methods, please let us know if you can explore new method too. Its a nice mechansim.

Regards,

Jayanta Sarkar

[TomD.inPDX]

I am wondering if you have to mimic this action with a custom servo motor profile.

[dbodar · Accepted solution]

Its done by CAM Mechanism....

In that you must have to define the LIFTOFF...

Value of Liftoff is 0.10

if I take 0.5 than interset are occured. Video Link : 5026

[TomD.inPDX]

Nice solution!

How did you figure out the cam profile?

[dbodar]

If I used 3D contact

than prob occured as shown in video

in this i done dynamic analysis

Video Link : 5031

[LndoVnBtchmrk]

Here's a different approach. I did what Tom suggested and used a servo for drive and driven wheels. The driven wheel's motion is defined by tabular data, but it's very accurate.

Always wanted to model a spherical geneva drive. Fun stuff.

Video Link : 5028

[TomD.inPDX]

Beautiful, Andrew!

[JoshH]

Wow, I second that, really nice piece of work Andrew! Might look interesting with another semi-sphere on top of that.

[LndoVnBtchmrk]

Why not double up the holding power too!

Video Link : 5036

I wonder if anyone has ever designed a hypoid-style geneva machanism before. You know, nonintersecting, nonparallel shafts.

[JoshH]

That's way cool!!!

[dbodar]

Can give me to dimension of sperical gevena drive...

or any internet link for dimension...???

[TomD.inPDX]

Any size you want. A little thought will tell you want has to be done to make the geometry.

Essentially, it is a conical boss (optional) and a pin at 45 degrees from the boss. So the slot has to be 45 degrees vertically as well.

Andrew, can you post the graph for the servo definition you used?

[LndoVnBtchmrk]

Models are attached. The data points for the 1st and second driven wheels are attached also.

Here's a segment of the first driven wheel's servo motor profile. The drive wheel just has a constant velocity of 360 deg./sec.

I half derived the equation of motion for the driven wheel, but the third dimension really complicated it. I ended up just indexing the drive wheel and measured the angles directly.

[TomD.inPDX]

Thanks Andrew. I was thinking it was a straight forward 90 degree cosine with a "rest period".

That one can be programmed fairly easily in the user defined table as well. But only if the input shaft is constant!

I suspect a cam link would be the right way to do this so it could be linked to the input. I haven't done cams yet. This may prove interesting. This would allow for varying input curves.

[TomD.inPDX]

Okay, one could hope. Not exactly a pure cosine curve.

[ClintWalton]

Hi Deapk,

It seems like you might have this resolved. If one of the user posts was correct, please mark the post as "Correct Answer."