Wave generator 1 is a cam of elliptical shape and rotates about fixed axis A. Flexible link 2, having teeth on its outside circumference, rotates about fixed axis B and meshes at two opposing areas with the internal teeth of circular link 3 which is rigidly attached to the base, i.e. fixed. A large number of teeth are simultaneously in engagement in two areas located symmetrically with respect to the minor axis of the elliptical cam. Balls 4 are arranged between wave generator 1 and flexible link 2 to facilitate radial deflection of the link. The transmission ratio from generator 1 to flexible link 2 is i₁₂=ω₁/ω₂=n₁/n₂=-z₂/2 where ω₁, ω₂, n₁ and n₂ are the angular velocities and speeds (in rpm) of wave generator 1 and link 2; and z₂ is the number of teeth of link 2, which is equal to z₂=z₃-2.
$2926$CxG,SW$