When mounting four-row tapered roller bearings, the components must be assembled in the correct order. To facilitate this, they are marked with letters (fig 1). All the components of one bearing are also marked with the same serial number so that mixing is avoided if several bearings are being mounted at the same time.
As in the majority of applications the direction of load is constant with respect to the outer ring only approximately one quarter of the outer ring raceway will be under load. For this reason the side faces of the outer rings are divided into four zones marked I to IV. The markings for zone I are also joined by a line across the outside diameter of the rings (fig 2). When the bearings are first installed it is customary for zone I to lie in the direction of the load. Depending on the operating conditions, the outer rings should be turned through 90° after a given period of service when the rolls are changed so that a new zone comes under load.
Detailed mounting and maintenance instructions will be supplied on request. If skilled personnel is not available to mount the bearings it is advisable, particularly where large bearings are concerned, to request the assistance of SKF service personnel. Further details of the SKF mounting service will be supplied on request.