FIELD OF THE INVENTION

The present disclosure relates to vehicle steering systems and, more particularly, to a stiffening sleeve for a steering column jacket.

BACKGROUND

Steering columns typically include a jacket assembly, which may include an upper jacket and a lower jacket. The upper jacket is sensitive to both vertical and lateral natural frequency. Increasing the material thickness of the entire upper jacket will result in an increase in the vertical and lateral natural frequency, but such a change also undesirably increases the upper jacket mass.

SUMMARY

According to one aspect of the disclosure, a steering column assembly includes a jacket having a first end, a second end, a jacket length, and an inner surface defining a bore. The steering column assembly also includes a steering shaft having an outer surface and a shaft length, at least a portion of the steering shaft located within the bore defined by the inner surface of the jacket. The steering column assembly further includes a stiffening sleeve having a radially inner surface, a radially outer surface, and a sleeve length, wherein the radially outer surface of the stiffening sleeve is fixed to the inner surface of the jacket.

According to another aspect of the disclosure, a steering column assembly includes a jacket having an inner diameter, a first end, a second end, and an outer jacket length. The steering column assembly also includes an inner steering shaft having an outer diameter and a length. The steering column assembly further includes a bearing between the inner diameter of the outer jacket and the outer diameter of the inner steering shaft, the bearing located at an end of the outer jacket, and the bearing radially supporting the inner steering shaft. The steering column assembly yet further includes a sleeve having an inner diameter, an outer diameter, a first end, a second end, and a sleeve length less than the outer jacket length. The steering column assembly also includes the sleeve located such that the outer diameter of the sleeve is in contact with the inner diameter of the outer jacket, and an end of the sleeve is not adjacent to an end of the outer jacket.

According to yet another aspect of the disclosure, a method of fixing a sleeve inside the other jacket of a steering column assembly is provided. The method includes an outer jacket having an inner diameter, a first end, a second end, and an outer jacket length. The method also includes an inner steering shaft having an outer diameter and a length. The method further includes a sleeve having an inner diameter, and outer diameter, and a sleeve length. The sleeve has a maximum outer diameter larger than the inner diameter of the outer jacket. The method yet further includes press-fitting the sleeve entirely inside the outer jacket such that the outer diameter of the sleeve is rigidly connected to the inner diameter of the outer jacket.

