Input: orange shaft having an inclined portion.
Output: yellow gear of tooth number Zy.
Pink gear (tooth number Zp) is stationary.
Green pin gear (pin number Zg = Zy) has revolute joint with the inclined portion of the orange shaft. It performs wobbling motion. Its rotation is transmitted to the output gear.
Zg is larger than Zp.
Output velocity is regular.
Rotary directions of the input and output are the same.
Transmission ratio i = (Zg – Zp) / Zy
Here:
Zp = 38 ; Zg = Zy = 40 ; i = 1/20.
This mechanism is called “Nutation drive” in “Mechanisms And Mechanical Devices Sourcebook”, Sclater & Chironis, 2001, page 244.