It's difficult to make a blanket statement, but the idea behind alot of these is to take something that required energy to produce, break it down somehow, and c

It's difficult to make a blanket statement, but the idea behind alot of these is to take something that required energy to produce, break it down somehow, and claim that the released energy is "free" and that makes it perpetual motion. If your machine has positive power output you have a perpetual motion machine. If you have a machine the has positive power output but also consumes a gear (and the power required to repair the gear is higher that the power output before it broke) then you have a gear-destroying machine.