Design of the adjacent construction

In the following sketches and tables, the design of the adjacent construction is described.

Pay particular attention to the precision of the connection areas, as any deviations will have an effect on the overall accuracy of the roller bearing and therefore the axis system.

In order to avoid a decline in bearing friction torque, running accuracy and running properties, the recommended tolerances must not be exceeded.

Press fits

In principle, if the fit is too tight, the radial bearing preload increases and thus…

…the following increase:
■ the surface pressure in the raceway
■ the bearing friction
■ the bearing warming
■ the wear

…the following reduce:
■ the maximum speed
■ the life time

Clearance fits

If the rotating bearing ring is not supported across the whole surface in clearance fits, the axis of rotation (bearing axis to table axis) is likely to be displaced.

The clearance from the fit table to bearing bore (also applies for the clearance bearing outer diameter to table with rotating outer ring) can add to the radial runout.

Targeted clearance fits for compensation of the growth of individual roller bearing rings may be expedient, but demand exact knowledge and temperature control of the individual rings. The risk of runout errors or the loss of the rotation centre of the rotary axis is to be observed accurately over all operating conditions of the machine tool.

No support or insufficient support of the inner ring leads to undefined operating conditions such as vibrations, runout errors and repeatability Errors etc.

Recommended minimum wall thickness of the table: