An eccentric gear mechanism, comprising an input drive having a centric portion rotated about an axis and an eccentric portion; a movable inner ring gear having outer circumferential gear teeth, so that said centric portion and said eccentric portion of said input drive turn in one direction against said movable inner ring gear, said inner ring gear being configured in such a way that it allows an eccentric movement by said inner ring gear and transfers a given turning force derived by said inner ring gear in an opposite direction to said one direction; an outer ring gear having inner circumferential gear teeth partially engaged with said outer circumferential gear teeth of said inner ring gear, so that when said given turning force is derived by said inner gear ring in said opposite direction said outer ring gear rotates around said axis, and said outer ring gear transfers said given turning force in said one direction outwardly along said axis.