Electric power steering apparatus

Abstract

A small gap is formed between a worm shaft 3 and a second bearing 20, so that the worm shaft can be tilted relative to the inner ring 20a of the second bearing 20 without fail when preloaded by a torsion spring 14. An elastic member 41 is provided in at least portion of a circumferential groove 40 in the small gap. The worm shaft 3 and the inner ring 20a of the second bearing 20 are not in contact with each other, and their metallic clank in the small gap can be prevented. By providing a projecting portion(s) 3b on one side or both sides, with respect to the axial direction, of the circumferential groove 40, the small gap between the worm shaft 3 and the inner ring 20a of the second bearing 20 can be made large, and it is possible to enlarge the range over which the worm shaft 3 can swing.

Description

technical field

[0001] The present invention relates to an electric power steering (electric power steering) device, which generates auxiliary steering torque through an electric motor according to the steering torque applied to the steering wheel, and then transmits the auxiliary torque to a steering mechanism by decelerating through a speed reducer on the output shaft. Background technique

[0002] In a known electric power steering device for vehicles, the rotational output of an electric motor for providing assist steering torque is transmitted to the output shaft of the steering device through a gear device while being decelerated to assist in the steering operation of the steering wheel. The steering force applied to the steering wheel. In such an electric power steering apparatus, power is transmitted to an output shaft while decelerating the rotation of the electric motor by a power transmission mechanism provided in a housing.

[0003] In the electric power steeri...

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