This is a harmonic drive, also known as strain wave gearing. It provides very high reductions can provide very high torque and does not suffer from backlash.
This technology is used and available commercially.
http://harmonicdrive.net/
It is distinctly different from Cycloidal gearing, but the two do share some attributes. Primarily, both advance the output by one tooth of an annular gear for every full rotation of the input shaft.