Depending on their design, components of double row tapered roller bearings can also be mounted separately. The individual rings of one bearing must be mounted in the correct order and position. They must also not be mixed with those of another bearing when several bearings are mounted at the same time. Therefore, some precautions have been taken to ease mounting:
- Components of one bearing are marked with letters that indicate their correct order and position (fig. 1).
- All components of one bearing are marked with the same serial number.
Special care should be taken not to deform or compress the relatively thin-walled intermediate rings when mounting smaller TDI design bearings. This can happen, for example, when tightening the cover screws and can have a negative impact on the axial clearance or the preload. Therefore, SKF recommends applying a cover with a centring spigot that is appropriate to the widths of the bearing and the housing seat.
If the knowledge and experience required to mount double row tapered roller bearings is unavailable, especially where large bearings are concerned, SKF recommends that the assistance of SKF service personnel be requested. Further details of the SKF mounting service are available on request.
In the majority of rolling mill applications, the direction of a radial load is constant. Depending on the ratio between axial and radial loads, usually only approximately one quarter of the outer ring raceway is under load. Therefore:
Outer rings are divided into four zones identified by a marking I to IV on the outer ring side faces (fig. 2), on request.
- Markings for zone I are also joined by a line across the outside surface (fig. 2).
For initial mounting, zone I (line across the outside surface) should be positioned in the direction of the load.
- Depending on the operating conditions, after a period of service the outer rings should be turned through 90° so that a new (the next) zone becomes the loaded zone.