Input: violet carrier of velocity Nv
Output: orange bevel gear of velocity No
Three bevel gears have the same tooth number.
Yellow gear block has yellow spur gear of Zy teeth.
Green gear block has green spur gear of Zg teeth.
Pink gear block has pink gears of Zp1 teeth (gear on the left) and Zp2 teeth.
Zy + Zp1 = Zg + Zp2
No = Nv(1-A)/(1+A)
Where A = (Zp1.Zg)/(Zy.Zp2)
For this case Zy = Zp2 = 21; Zg = Zp1 = 20
No = Nv/20.51
If Zy = Zp2 = 101; Zg = Zp1 = 100
No = Nv/100.5