Rigidly adjusted FAG precision bearing arrangements, especially those with a short spacing between the bearings, react with a high degree of sensitivity to temperatures between the shaft and housing, since the preload within the FAG bearing set may increase sharply and the bearing sets may brace against each other if the sliding seat does not function.
Radial bracing may occur in particular with FAG spindle bearings having a contact angle of 15°. This also applies to FAG cylindrical roller bearings or non-locating bearing pairs with a sliding seat.
In contrast, rigid bearing arrangements with a large spacing between the FAG bearings, elastically adjusted bearing arrangements and bearings with a contact angle of 20° or 25° are less sensitive.
FAG bearings with ceramic rolling elements generally have lower operating temperatures. Furthermore, the increase in the preload in the rigid system with increasing T is smaller in this case than with steel balls.
For rigidly preloaded bearing arrangements, speed reduction factors must be applied.
In FAG bearing arrangements adjusted by springs or hydraulic means, the stated speeds are achieved due to the lower thermal sensitivity, see dimension tables. In bearings with a contact angle of 15°, the T between the shaft and housing may restrict the speed.
For the springs, a preload force is selected that corresponds to at least the mean bearing preload M.