Construction notes

In order to ensure proper functioning of the bearing, the tolerances and details according to the shaft and housing recommendations must be strictly observed for the surrounding parts of the bearing.
The bearings are to be supported with an appropriate construction. Non-adherence to these principles leads to severely reduced performance characteristics or to the complete loss of all bearing functions.
Based on the example of the AXRY bearing, the main design criteria are presented below.

Whole-surface support of at least one flat surface and the bearing bore

The preload in the bearing is generated through the inner ring screw connection. The rings deform due to the high preload forces. These deformations are reduced or avoided through the adjacent construction. After being screwed in position, the bearing has the defined preload.

All AXRY bearings have been designed and calculated on the basis of this principle. Deviating adjacent constructions can lead to a loss of rigidity and running accuracy or a severe increase in friction. More design-flexible bearing types such as the AXDR and AXCR help to reduce this issue.

In case of screw-on NF metal rings via which the preload is applied, please ensure that the preload forces are applied evenly to the bearing, for example via steel rings which are screwed on with the rings.

Edge rounding / radii

Excessively large radii in the connecting parts prevent the correct tightening of the bearing onto shafts or prevent the bearing from lying flat in the housing. The result is distortions in the bearing.

Perpendicularity / cylindrical shape and roundness of the shaft

Incorrect form tolerances lead to undefined operating conditions. Both distortions and poor support of the bearings may occur.

Press fit of shaft

Press fits lead to widening of the inner ring and thus to radial preload increases.

The higher the requirements on the accuracy and the speed are, the more precise the fits must be. In highly dynamic or highly precise applications, these are ensured via individual pairing of the bearings with the connecting parts.

For this reason, the exact connection measurements are listed in the enclosed inspection report.

Clearance fit of shaft

The rotating ring is to be supported by a transition fit to avoid displacement of the rotary axes table to bearing. Otherwise, the clearance fit can add to the radial runout.

Only in this case radial running accuracy of the bearing on the table is reproducible.

This applies in the same way for applications with rotating outer ring.

Avoid double centring

The bearings require the greatest possible support across the whole surface in the area of the bearing bore. Further centring in the bearing bore should be avoided.

If this proves unavoidable in the design, the additional area to be centred must be as short as possible and have more clearance.

Fastening thread in the adjacent construction