Cylindrical Roller Bearings SKF NNU4934 BK/SPW33

The SKF NNU4934 BK/SPW33 cylindrical roller bearing, with a 170 mm bore, brass cage and tolerance class SP, provides high-precision radial support.

The NNU4934 BK/SPW33 cylindrical roller bearing is a double-row non-locating bearing designed for demanding industrial applications involving very high radial loads. SKF manufactures this version with a tapered bore with a taper ratio of 1:12 and an open design. With dimensions of 170 mm bore diameter, 230 mm outer diameter and 60 mm width, this roller bearing can accommodate large radial forces. The solid brass cage guides the two rows of rollers and retains its dimensional stability at temperatures between –30 and +150 degrees Celsius.

In which installation scenarios does the NNU4934 BK/SPW33 idler bearing prove its worth?

This double-row floating bearing is primarily used in applications where designs require high radial stiffness and running accuracy. As a floating bearing, the bearing assembly compensates for thermal length changes in the shaft during operation without any constraint, as the inner ring can be removed from both sides. Typical applications are found in precision engineering, in bearing arrangements subject to high radial loads and requiring precise shaft guidance. The lubrication groove integrated into the outer ring, together with the lubrication holes, simplifies the continuous supply of lubricant to the contact zones during operation.

What are the advantages of tolerance class SP and the tapered bore?

Tolerance class SP designates this bearing as a high-precision version with tightly defined dimensional and running tolerances. In combination with the significantly reduced radial bearing clearance, a play-free or specifically preloaded bearing arrangement can be achieved. Thanks to the tapered bore with a 1:12 ratio, the bearing is mounted on a tapered shaft seat. The radial operating clearance can be adjusted during assembly via the axial displacement.