In the left side, Harmonic ring gear(or circular spline, green ) has 75 teeth , and output rotation. Wave gear(or flexible spline , yellow) has 72 teeth. Gear ratio by harmonic unit is 75/3 = 25 : 1. Tooth profile is due to applied cosine.
Planetary ring gear has 64 teeth. Each planet gear has 23 teeth with shaft fixed. Sun gear(red) has 16 teeth and input rotation Gear ratio by planetary unit is 4 : 1. Tooth profile is involute.
Total gear ratio is 25x4=100 : 1.
In the right side, Harmonic specification is the same as left side one.
Use of a triangular elliptical roller bearing for wave generator.
Planetary ring gear is fixed and has 54 teeth. Each planet gear has 18 teeth. Sun gear(red) has 18 teeth and input rotation Gear ratio by planetary unit is 4 : 1. Tooth profile is involute.