This wonderful site presents animations of 507 mechanical movements first published in a book by Henry T. Brown in 1868, the full title of which is:
Five Hundred and Seven Mechanical Movements: Embracing All Those Which Are Most Important in Dynamics, Hydraulics, Hydrostatics, Pneumatics, Steam Engines, Mill and Other Gearing, Presses, Horology, and Miscellaneous Machinery; and Including Many Movements Never Before Published and Several of Which Have Only Recently Come Into Use
The site is a work-in-progress...not all of the movements have been animated yet. This short video shows movement #123:
You can buy a paperback version of the original book or browse/download the entire thing at the Internet Archive.
See also this great explanation of differential gears and especially Ralph Steiner's 1930 short film Mechanical Principles, in which we see many of the mechanisms from Brown's book actually working:
Warning: if you start Steiner's film, you'll probably end up watching the whole thing...it's mesmerizing, particularly when the gears come in around ~2:30.