Rack and Pinion Gear Design calculator

[karthur1]

I have a pinion gear that I need to do a strength calculation on.  I don't need a model, only the calculations for the rack and the pinion.  Here is what I know about the pinion gear:

15 teeth

25° PA

Full Depth tooth

7.162 PD

2.0944 Dia. Pitch

2.25in thick

I am confused about how I  treat this since it is a Rack and pinion and not two gears.  Which design guide should I be using?  I tried to use the "Total unit correction", but I don't know what I should use for the number of teeth for the Rack.  How do I correct the unit correction error?

[BMiller63]

did you ever figure this out?

if not would someone from AD care to provide an answer?

[karthur1]

I sent a support request in on this one.  What the tech said was that Inventor can't do racks.  Even though the preview tabs are labeled as such, it just will not calculate it.  No way to get it to model the rack either.  He said it was logged as a wishlist item.

When I get a chance to get back on this, I am going to use two gears to see if the gear will carry the load.

[ryan_simms]

It's been 4 years.  Can Inventor do racks now?

Thanks...

[JDMather]

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@ryan_simms wrote:

It's been 4 years.  Can Inventor do racks now?

Thanks...

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You might want to expand on that question. 

Rack and pinion analysis as per the topic of this thread?

Semi-automatic creation of rack and pinion?

Inventor could always do racks.

One of my 1st semester students did the rack in the Arbor Press assembly used in the tutorials many years ago.

[rahere3VW3S]

I always knew the major argument I had with my MechEng dad long ago would come in useful.

The constraints on a worm gear and pinion, namely that the worm drives the pinion but not the reverse, are caused by the fixed relationships between the bearings on each. But if the bearings on the worm and the bearings on the pinion are separated, then driving the pinion makes it want to walk along the worm gear, treating it like a rack.

So in design terms, use the project gear chain builder to build a worm gear with the pinion you want to use. Then take a profile along the axis of the worm and turn it into a work plane, and project the cross-section of the worm unto it. Then extrude it either side linearly, and you have your basic rack element. Finally delete the worm, without deleting its descendants.

Next question, is there a way to "extrude" such a unit into repeats? And how does the pinion handle bends? I'd suggest mounting it on a vertical bearing, so it can twist somewhat, which would imply an undercut inside the curve on the rack. 

It might be interesting to have an "imprint" tool, if anyone knows of one, returning a locus of the path of a moving part. Its complement then becomes the rack.

[JDMather]

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@rahere3VW3S wrote:
...It might be interesting to have an "imprint" tool, if anyone knows of one, returning a locus of the path of a moving part. Its complement then becomes the rack.

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Trace command in Dynamic Simulation Environment.

[10294LX8BF]

12 years later and Inventor still can't do racks.