CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Stage Entry of International Patent Application Serial Number PCT/EP2018/076720, filed Oct. 2, 2018, which claims priority to German Patent Application No. DE 10 2017 123 150.1, filed Oct. 5, 2017, the entire contents of both of which are incorporated herein by reference.

FIELD

The present disclosure generally relates to steering systems, including electromechanical power steering systems.

BACKGROUND

A known electromechanical power steering system has an electric servomotor, which drives a worm shaft which meshes with a worm gear, which is arranged on a steering shaft or directly on a steering pinion, which engages with a rack. The worm shaft is coupled to a shaft of the electric motor. The worm gear is connected in a rotationally fixed manner to the steering shaft or the steering pinion. The worm shaft of a conventional worm gear mechanism has a fixed bearing at its drive end and a floating bearing at its free end.

Laid-open application DE 10 161 715 A1 discloses a worm gear mechanism in which the worm can be pivoted perpendicularly to the axis of rotation and is supported via a bearing. The worm shaft is subjected radially to a prestressing force and is pushed against the worm-gear toothing. The prestressing force is provided here via a spring and a pressure-exerting device. This solution proves to be disadvantageous since the occurrence of noise cannot be avoided.

DE 10 2014 105 921 A1 discloses a pivot bearing which is accommodated in a sleeve which has two radially opposite and radially inwardly or outwardly directed bearing noses for forming the pivoting element. An outer ring of the bearing lies just loosely against the bearing noses and can move freely. This gives rise to undesired development of noise and friction.

Thus a need exists for an electromechanical power steering system which has a worm gear mechanism in which noise and friction can be reduced.

