Sprocket FEA

[benko]

I was wondering if anyone knew how to do a proper FEA of a drive sprocket in Solidworks using a chain that's available in the "Toolbox". I appreciate any feedback.

[Buckingham]

In order to do a proper FEA of the ENTIRE sprocket, you would need to know how the chain distributes load to each tooth. I would imagine that things like installed tension and tight/loose spots in the chain would play a large part.

If you are interested in the teeth, I would suggest you FEA a single tooth. If you are interested in shaving weight out of the sprocket body, model the teeth as a single circumferential surface and apply a uniform or non-uniform load to that surface (pick whichever assumtion you feel comfortable with, or do both).

[kwancho]

If you're trying to do teeth, look it up in a machine design textbook.

[Joy Pathak]

joy.pathak@gm.com
or
wangbang609@hotmail.com

Email me at that address and i will send u a full solidworks manual.. its almost 500 pages... and shud help answer your questions.(atleast i would hope so) Its a PDF file so i can send it through email.
If you need any ANSYS.. manuals... I have those too.. let me know. It might take a day or 2 i am very busy at work. but if you left an email I will make sure to send it to you.

Sincerely
Pathak

[benko]

If I FEA a single tooth, what load do I apply to the tooth if I know the torque at the shafts.

[billywight]

Why are you preforming FEA on a single tooth? The setup for that would be very complicated and most likely inaccurate. Look around at what others run and use this as a guide - you will most likely be limited by the chains tensile strength rather than the tooth strength of the sprocket. If you're looking to make an ultra-light sprocket, you could run an FEA without teeth and apply a torque to the outer surface. You might just consider buying a sprocket and being done with it - there isn't too much weight to be saved there and there's probably much more benificial places to spend your time.

[Parker]

You know torque at which shafts? Either way, you should be able to figure out the load from the moment that is being applied to the shafts.

[benko]

I first designed the sprocket by applying a torque (that was calculated by multipling our engine torque by primary reduction, by first gear, and by the front/rear sprocket ratio) to the outer surface of the sprocket (with the teeth removed). I just wasn't sure if the teeth would shear off first or the main body of the sprocket would deform first. What is the best way then to FEA a sprocket? Thanks in advance.

[adrial]

There are calculations out there to figure out the distribution of load to each tooth on the sprocket. Only the first 10 teeth on the main sprocket (say around 50 tooth) will really be taking any load under acceleration. It is invalid to assume an even distribution, but I dont know the equations as I wasn't actually the person who did the analysis.

Anyway, we applied those loads to a full model of the sprocket (teeth and mounting holes included).