Locating methods

Bearings with a cylindrical bore

Bearing rings that are mounted with an interference fit typically have one ring that abuts a shoulder on the shaft (fig. 1) or in the housing. On the opposite side, the inner ring is normally secured by a KM lock nut with an MB lock washer attached to the shaft end (fig. 1) or an end plate (fig. 2). Outer rings are typically located by a housing cover (fig. 3) or a threaded ring (fig. 4).
Instead of integral shaft or housing shoulders, spacer sleeves or collars can be used between the bearing rings or between a bearing ring and an adjacent component, such as a gear (fig. 5).
The use of snap rings to locate rolling bearings axially, saves space, enables fast mounting and dismounting, and simplifies the machining of shafts and housing bores. If normal or heavy axial loads have to be supported, an abutment collar should be inserted between the bearing ring and snap ring, so that the snap ring is not subjected to excessive bending moments (fig. 6). The usual axial play between the snap ring and snap ring groove can be reduced, if necessary, by choosing suitable tolerances for the abutment collar or by using shims.
Another way to locate a bearing axially, which is typically found in super-precision bearing applications, is to use a stepped sleeve with a tight interference fit on the shaft. For detailed information, refer to Super-precision bearings.

Bearings with a tapered bore

Bearings with a tapered bore, mounted directly on a tapered shaft seat, are typically located axially on the shaft by a lock nut (fig. 7).
When using an adapter sleeve on a stepped shaft, an L-shaped spacer ring, not supplied by SKF, is fitted between the shaft shoulder and inner ring on one side. A lock nut locates the bearing relative to the sleeve on the opposite side (fig. 8). Where plain shafts without integral abutments are used (fig. 9), the friction between the shaft and sleeve governs the axial load carrying capacity of the bearing (→ Self-aligning ball bearings and Spherical roller bearings).
When bearings are mounted on withdrawal sleeves, an abutment, such as a spacer ring, which is frequently designed as a labyrinth ring, must support the inner ring. The withdrawal sleeve is located axially by an end plate or lock nut (fig. 10).
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