This is an ideal mass- and inertialess gearbox which transforms a 1D-rotational into a 1D-translational motion. If elasticity, damping or backlash has to be considered, this ideal gearbox has to be connected with corresponding elements. This component defines the kinematic constraint:
(flangeR.phi - internalSupportR.phi) = ratio*(flangeT.s - internalSupportT.s);