This drive consists of a small gear (in pink) and a big one (in green) but its velocity ratio is 1. Screw gear causes this paradox.
Normal module mn = 2 mm
Pink gear:
- Helix angle B1 = 0 deg.,
- Face module ms2 = mn = 2 mm
- Tooth number Z1 = 18
- Pitch circle dia. D1 = 36.0 mm
Green gear:
- Helix angle B2 = 45 deg., right hand
- Face module ms2 = 2.83
- Tooth number Z2 = 18
- Pitch circle dia. D2 = 50.91 mm
Angle between gear axles E = B1 + B2 = 45 deg.
Velocity ratio: i = Z2/Z1 = 1 (not D2/D1 = 1.41)