Drive device for an adjustable part of a vehicle

Drive device for displacing a vehicle part between end positions, comprising an electric motor that is connected by a reduction gear to a driving pinion located on a drive shaft, the driving pinion being connected to the vehicle part so as to drive it, a switching device controlling the motor to stop the motor in at least one predetermined position of the vehicle part, a switch wheel for actuating the switching device, and an eccentric gear train which, during displacement of the vehicle part between its end positions, causes the switch wheel to rotate less than 360.degree., the eccentric gear train having an external body internal gear with an internal toothing which is coaxial to a common shaft of the reduction gear and eccentric gear train, an eccentric disk that is connected to the common shaft for rotatin therewith, and an internal body external gear that has an external toothing which is meshed with the eccentric gear train and has at least one tooth less than the external body internal gear, the internal body external gear being supported on the eccentric disk and being rotatable with the eccentric disk;

• wherein the internal body external gear is prevented from rotating with to the external body internal gear and is guided by a single stationary guide bolt for movement back and forth along an adjusting axis that intersects the axis of the common shaft;
• and wherein the external body internal gear is connected to the switch wheel for rotation therewith wherein the reduction gear has a worm-gear shaft driven by the motor and a worm wheel that meshes with the worm-gear shaft, the worm gear being located on said common shaft and being connected to the common shaft for rotation therewith;
• and wherein the eccentric disk and the worm wheel are formed in one piece with each another.