Spur Gear and Rack

[amerdsp]

Hello all,

Can anyone guide me how to go about designing a spur gear and rack? Here is what I have so far in Inventor Pro 2009:

 

- A cylinder (this will be the gear)

- A square rod (this will be the rack)

- Tangent constraint between cylinder and rod.

- In Dynamic simulation, I produced a rolling joint.

 

Now when I want to create the gears using design accelerator, how do I specify the rod as the 2nd component? I do not have that option.

 

I am new to inventor and being an electrical engineer who does not know much about gears is not helping either.

 

Any hints or pointers appreciated.

 

Thank you for your time and help.

 

A

[shift1313]

amerdsp, you shouldnt need to create the cylinder and square rod. You should be able to have the design accelerator create these components.

 

What is your end goal for these? are you designing some sort of assembly and need to actually make these parts? Or are you simply just playing around?

[Hopinc]

Hi Matt,

 

I think you will find that there is no facility within Inventor for creating a rack per se. I came across this shortcoming myself some time ago when I was asked to design a vacuum conveyor system for a customer of mine. In the end I used the design accelerator to create a single spur gear and generated the rack by drawing an involute curve gear tooth to match and patterning the extruded cut along the rack bar.

 

I got the involute information from the internet rather than looking it up in text books, a quick search will reveal what is needed.

 

If there is an automated way of doing this, I could not find it. No doubt J.D. will put me right if there is.

 

Regards all.

 

Dave

Edited September 28, 2010 by Hopinc

[amerdsp]

amerdsp, you shouldnt need to create the cylinder and square rod. You should be able to have the design accelerator create these components.

 

What is your end goal for these? are you designing some sort of assembly and need to actually make these parts? Or are you simply just playing around?

 

Then I do not know how to make design accelerator do that without the cylinder and square rod.

 

Yes, it is part of an assembly an I need these parts among many others that I have successfuly made.

 

Thank you for your help.

 

A

[JD Mather]

You do not need to actually model the teeth for Dynamic Simulation. But if for some reason you really want the teeth there is an example in the Arbor Press in the Tutorials folder.

[Hopinc]

AMERDSP - If you log on to "3D Content Central" you can register and download parts from commercial manufacturers and individual users. If you go to the link shown below you can download a model of a gear rack (within a range of DP values):

 

http://www.3dcontentcentral.com/parts/browse/Gears/Mekanex-Maskin-AB/19434/19434/Models.aspx?title=Gear+racks&isredirect=true&level=6

 

This may save you some time.

 

Regards.

 

Dave

[shift1313]

Dave, I took a quick look and you are right i didnt see rack available without downloading it form content central. I guess i was thinking ring/pinion:)

[Hopinc]

Hi Matt,

 

I now have an inside contact at Autodesk and have been highlighting some of the anomalies within Inventor. He has been passing them on to those concerned. This is one that I mentioned to him recently.

 

I find it particularly strange that whoever created the design accelerator forgot the gear rack, but then again it is nothing new for Inventor to have these silly little anomalies.

 

Another one cropped up recently that had sunk to the back of my mind. As a user of SolidWorks you will know just how easy it is to scale a complex part - why is this feature missing from Inventor? SW also has a gear rack generator in the "Toolbox."

 

There is no guarantee that anything will be done about my suggestions, but I live in hope.

 

Regards all.

 

Dave

[rataylor]

hopefully this video tutorial I uploaded can help. Later, RT.