Found on Google from drivetrainhub.com

Found on Google from differencebox.com

Part of the Fundamental Manufacturing Processes Video Series, this program introduces many primary gear terms and definitions, including involute curve, base circle, pitch circle, pitch point, line of action, outside circle, root circle, and many others.…

This is an epicycloidal gear train: the smaller pinion roll around the bigger gear.

Some related videos:

Hypocycloidal Gear Train:
http://www.youtube.com/watch?v=BiZblvSX4XA

Planetary Gear Train:
http://www.youtube.com/watch?v=ECljAo1q1RQ

Gears:…