The steering gear has a drawn cup needle roller bearing HK on the non-locating bearing side. A ball bearing KL is fitted on the locating bearing side.

The arrangement selected allows a compact design with low frictional values, which is beneficial in terms of steering wheel movement forces.

The two bearings are protected by the surrounding construction. The bearing is greased when it is fitted and is thus maintenance-free for life.

A combination of a needle roller bearing LEN and a four point contact ball bearing KLX was selected for the steering column bearing arrangement.

The needle roller bearing LEN:

• does not have an inner ring - the needle rollers run directly on the steering shaft

• provides clearance-free support for the steering shaft

• damps out noise and vibrations

• compensates for tolerances of the adjacent construction - the steering shaft and the tube are generally cold formed without subsequent reworking and are therefore economical components

• have low friction

• are easy to assemble.

A needle roller bearing LEN consists of:

• a rubber tolerance ring

• a split outer ring

• a needle roller and cage assembly with rolling elements

• a thrust washer.

The NBR hardness of the rubber tolerance rings is 65 to 80 Shore A - which is matched to the required rigidity.

The exact specification for the rubber mixture and the subsequent technical delivery conditions ensure that the NBR quality remains constant throughout the operating life of the bearing. The steering comfort level is therefore maintained over the whole operating life.

The rubber tolerance ring provides the preload for the needle roller bearings. Once the bearings are pressed into the tube, the tolerance ring subjects the split outer ring and rolling elements to a defined preload.

The preload is set such that:

• an adequate rigidity is achieved

• the displacement force of the shaft is not too high.

A limited displacement force is particularly important if the position of the steering shaft has to be corrected during assembly in the vehicle.

The split outer ring and rolling element set are matched to each other. The raceways are thus protected from deformation and damage whilst under load. The split is set at an angle to the rolling element axis and is staggered. The rolling elements can therefore overroll the split without any detriment to their function.

The high rigidity of the steering column bearing arrangement is achieved by means of the four point contact ball bearing KLX, which is positioned at the point where the highest force acts, i.e. close to the steering wheel.

This locating bearing on the steering wheel

• provides clearance-free axial and radial location for the shaft

• compensates the longitudinal tolerances in the steering column by means of integral springs and the spacer ring

• helps with assembly due to the retaining lugs on the tolerance ring - locates the shaft during transport.

The bearing arrangement is clearance-free due to to the springs in the four point contact ball bearing KLX. These subject the bearing outer rings and the ball set to preload.

The clamping unit for rake adjustment is fitted with an axial needle roller and cage assembly AXK, an axial bearing washer AS and needle rollers NRA.

These bearing arrangements must essentially support static forces; needle roller bearings are particularly suitable for this function since they can support very high forces in small spaces.