From the video description:
This is an automatic transmission model I designed and 3D printed (you can download the design here: http://www.thingiverse.com/thing:34778). This type of gearing arrangement is common in automatic transmissions in cars, though the clutches and brakes and hydraulics that control them are far more complex than modeled here. Also missing is the torque converter.
These gears are known as herringbone, which are not generally found in real transmissions because they are too difficult to machine. However, they are easy to print, and they have the advantage of being self-centering.