Belt drives

Hi everyone, I'm from Hervey Bay and I'm lucky enough to fly a trike around the Bay and occasionally across to Fraser island which is quite magical! :big_grin:

I'm interested in information about belt drives and pulleys for a project i have in miind. Are there stock bolt-on reductions available or does one have to make them up and where can one get belts and pulleys anyway? Also are there any basic rules I need to know e.g. someone told me I shouldn't reduce exactly 2:1 (or 3:1) 'cos it would set up a harmonic vibration. What sort of belt would be bestto transmit about 60hp and 6000 revs - e.g. single or double V, ribbed or toothed? Any good websites? :confused:

Any advice appreciated. Thanks,

David

I'm not an expert, but there's a couple of belt drive programs you can download.

http://www.gates.com/europe/designflex/ is good. Optiflex also has one which is a bit more complex, but gives similar results.

I have a 50mm V-belt on my project... you would need 85mm for your 60hp. 6000RPM is about the max for toothed belts. Smallest sprocket is 28 teeth, choose the large sprocket to to give you the right reduction ration.

I don't think the "Avoid 2:1" rule applies. My understanding was that was for geared drives, where you wanted to avoid having the same teeth always engaging with each other. But I could be totally wrong about that. Your harmonic vibration thing sounds quite probable.

I got my belt from a good engineering supply store... they had to order it in, but it wasn't a problem. Price was about NZ$100 for the belt. I already had the pulleys -- they came with the project when I bought it.

If you go toothed-belt, You do need to very careful about aligning the 2 pulleys accurately, and getting the right tension. The good news is that the belts don't stretch, so once set up, it's good for a while.