Worm 1 rotates about fixed axis A-A and its threads a mesh with teeth b of worm wheel 2 which rotates about fixed axis B. Axes A-A and B are perpendicular to each other and do not intersect. The transmission ratio of the mechanism is • i₁₂=ω₁/ω₂=z₂/z₁=(R₂/R₁)(1/tan(β)) where ω₁ and ω₂ are the angular velocities of worm 1 and worm wheel 2, z₁ is the number of threads, or starts, on worm 1, z₂ is the number of teeth on worm wheel 2, R₁ and R₂ are the pitch radii of worm 1 and wheel 2, and β is the lead angle of the worm threads. The tangent of the lead angle is tan(β)=(z₁t)/(2πR₁)=(mz₁)/(2R₁) where t is the axial pitch of the worm (and circular pitch of the wheel) and m is the module of the gearing. Radii R₁ and R₂ are determined by the equations: R₁=(mz₁)/(2 tan(β)) and R₂=(mz₂)/2.
$2807$WG,3L$