How to create a movement of rotating gears

You can give collision a try! I am just sharing what I know, which is not everything! lol!

My personal experience with collision is it is not very precise. So something like your cogs where it looks like you want them to fit together nicely my *guess* is wont work like what you want. But feel free to prove me wrong! ;-).

You have two basic approaches that come to mind. You can use stop frame animation - basically draw each of a series of positions and animate between them (using the Cycle Layers behavior). Low tech, but can be used to animate anything!

The other approach is to create a puppet (either one with both cogs, or one per cog) and put a Transform behavior on the cog layer. You then use key framing to change the rotation value over time. You start and stop both rotating at exactly the same time that way. That is, one is not pushing the other - it just looks like it because you timed the animation carefully to achieve the look you are after. 

The advantage of the second approach is it gives you more control over the speed they cogs are rotating at. Cycle layers has the speed controlled by fps and the number of frames you draw, so is less flexible. Using rotate you can pick any speed you like.