I can see how that somewhat resembles the hub of a spoked wheel from a wagon, cart or even early automobile, but these generally have two sides which are bolted together, and often other parts to secure the spokes thus I don't believe it to be that (it appears to lack the holes for the bolts). But you're not insane for your initial guess.
I would agree with it as a belt pulley, but now you have to go find the rest of the machine so we know what it's from!