Gear Toy is a d3.js example for creating simulated gear animations with SVG.

Check it out

See the full Gear Toy (Demo) →

What's all this then

I made this as an animation for my site's home page, where you can also see it in action.
It's based on this more limited example by mbostock.

I improved it by adding a (basic) simulation of the gears, where power is actually trasmitted.
The gears also can be dragged around and will automatically mesh correctly when they get close.