In most applications where thermal expansion and contraction of the shaft must be accommodated without inducing an axial load on the bearings, a locating/non-locating bearing system is typically used.
The bearing in the locating position must be able to locate the shaft axially in both directions. In machine tool applications, a set of angular contact ball bearings or a pair of angular contact thrust ball bearings can be used.
Non-locating bearings must accommodate thermal expansion and contraction of the shaft. Cylindrical roller bearings are well suited for this because they accommodate shaft movements relative to the housing, within the bearing (fig. 1). This enables the bearing to be mounted with an interference fit on both the inner and outer rings.
If paired angular contact ball bearings are used in the non-locating position, either the inner or outer ring of both bearings must have a loose fit so that they can slide on the shaft or in the housing. A loose fit, however, has a negative effect on system rigidity.