These are involute bevel gears that are designed to mesh accurately with minimal vibration. There are three pairs of bevel gears, with gear ratios of 1:1, 1:2, and 1:4. They have 20:20, 20:40, and 10:40 number of teeth respectively. Gears from each pair can only mesh accurately with each other. The gears were modeled on a millimeter grid and can be easily animated.
I have included both the original NURBS geometry for the gears and converted polygonal geometry.
You may download the very high resolution renders of the gears to see for yourself that the gears mesh perfectly.