Patent ID: 8601890

Claim:
A driving device for a hatch in a motor vehicle, the device comprising: a first fastening element configured for connection to a stationary structural component; a second fastening element configured for connection to a movable structural component; a spindle drive comprising a threaded spindle having an axis of rotation and a spindle nut arranged on the threaded spindle; a rotary drive comprising a driveshaft for rotating said threaded spindle about said axis of rotation to move the first fastening element and the second fastening element axially with respect to each other; a stroke detection sensor for continuously detecting the position of the movable structural component, the stroke detection sensor comprising a rotatable sensor element driven in rotation by the driveshaft and a stationary sensor element for continuously detecting the rotational position of the rotatable sensor element; a gear reduction unit between the driveshaft and the rotatable sensor element; and a safety coupling configured between the rotary drive and the spindle, wherein the safety coupling can be opened, wherein the gear reduction unit comprises: an annular gear which is fixed against rotation, the annular gear having an inside diameter; an eccentric cam fixed to the driveshaft for driving the annular gear to wobble; a gear wheel having an external diameter which is smaller than the inner diameter of the annular gear, wherein the gear wheel engages the annular gear so that the gear wheel rotates less than the drive shaft, wherein the rotatable sensor element is driven to rotate by the gear wheel.