Detailed Product Description
Four-row tapered roller bearings are used successfully worldwide
for rolling mill bearing arrangements where rolling speeds are slow
to moderate. Because of their design they are able to take up those
axial loads which occur in such applications in addition to radial
loads and generally no separate thrust bearings are required in
such arrangements. This means that the roll necks can be relatively
short and the chocks at both sides of the roll can have the same
design.
Four-row tapered roller bearings, because of their design, must
be installed as complete bearings in the chocks. To enable quick
roll changes to be made they must therefore have a loose fit on the
roll necks. Loose fits have the disadvantage that the inner rings
wander on their seats under the prevailing load conditions causing
wear to the seats which normally have a lower hardness than the
rings. To alleviate the effects of a loose fit to some extent, i.e.
to reduce wear, SKF bearings have a helical groove in the bore
and/or lubrication grooves in the side faces of the inner rings.
These grooves enable lubricant to be supplied to the contact
surfaces of the inner ring and seat. Additionally, the
grease-filled grooves can absorb the wear particles.
SKF produces an extensive range of four-row tapered roller
bearings which covers not only the conventional designs with
intermediate rings between the outer and/or inner rings, but also a
new design with modified rings which integrate the intermediate
rings. The particular advantages of these four-row tapered roller
bearings without intermediate rings which have been developed by
SKF include
To enable these advantages to be exploited in all applications,
those bearings of conventional design with intermediate rings
produced by SKF are gradually being converted to the new
design.
SKF four-row tapered roller bearings are produced in the TQO and
TQI designs. The main difference is the configuration, or
arrangement, of the roller and cage assemblies and the number of
inner and outer rings dictated by this. TQO bearings are, however,
used almost exclusively.
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