ELECTROMOTIVE AUXILIARY DRIVE

摘要

An electromotive auxiliary drive used in vehicles, e.g. a drive for a window lifter system, comprising an armature shaft (3) which is rotationally mounted in a housing (2), a worm (6) which is provided on the armature shaft (3) and which forms a worm gear in conjunction with a worm wheel (7), also comprising at least one axial stop (10) for the armature shaft (3) in order to transfer axial forces from the armature shaft (3) to the housing (2). The at least one axial stop (10) comprises at least one stop part (11) which forms a stop surface which is arranged concentrically in relation to the axis of the armature shaft (3) and which is rotationally secure and shaped in the form of a ring or partial ring. The stop surface is located directly opposite a counter surface concentrically surrounding the axis of the armature shaft (3) and is provided with a reverse-rotation lock function. By selecting a combination of material for the armature shaft (3) in the region of the counter surface and material for the stop part (11) in the region of the stop surface and/or by specially configuring the surface of the counter surface and /or stop surface and/or selecting the size of the stop surface or average radius of the stop surface, it is possible to adjust the friction force or friction moment between the armature shaft (3) and stop part (11) such that rotation of the armature shaft (3) can be prevented by said friction force when an external torque acts upon the worm wheel (7).