Input: pink shaft having an inclined portion.
Output: blue gear of tooth number Zb.
Green pin gear (pin number Zgn) has revolute joint with the inclined portion of the pink shaft. It performs wobbling motion.
Zgn is larger than Zb.
Grey gear (tooth number Zgy) is stationary. It keeps the green gear from rotating because Zgy = Zgn.
Output velocity is regular.
Rotary directions of the input and output are opposite.
Transmission ratio i = (Zgn – Zb) / Zb
Zb = 38 ; Zgn = Zgy = 40 ; i = 1/19.
This mechanism is called “Nutation drive” in “Mechanisms And Mechanical Devices Sourcebook”, Sclater & Chironis, 2001, page 244.