Four row tapered roller bearing
RKB Europe

RKB four-row taper roller bearings are installed as complete assemblies and take axial loads in addition to heavy radial loads, so that generally it is not requested separate thrust bearings in such arrangements.
They are commonly used in rolling mill applications.
For quick roll changes, the bearings have a loose fit on the roll necks, but there is the disadvantage that the inner rings wander on their seatings causing wear. To reduce these negative effects, RKB bearings have a helical groove in the bore and 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 seating.
Since wear and shock resistance under heavy rolling loads is a requirement for roll neck bearings, highest quality carburizing grade bearing alloy steels are normally used in RKB four-row taper roller bearings.
Besides, for large size bearings, pierced rollers and steel pin-type cage for maximum load ratings possible are applied.
The induced thrust resulting from radial loading is cancelled within the double cones and it eliminates excessive loads on clamping and spacing members.