Wheel 1, designed as a worm, rotates about fixed axis A and has helical tooth a which meshes with rollers 3 of link 2. Rollers 3 rotate freely about axes C of pin wheel 2 which rotates about fixed axis B. Axes A and B cross at an angle of 90°. The transmission ratio from worm 1 to pin wheel 2 is i₁₂=ω₁/ω₂=n₁/n₂=-z₃ where ω₁, ω₂, n₁ and n₂ are the angular velocities and speeds (rpm) of worm 1 and pin wheel 2, and z₃ is the number of rollers 3 mounted on p in wheel 2.
$2590$PG,3L$