SKF 22218 E/C4 Pendelrollenlager (90x160x40)

As a spherical roller bearing, this bearing carries very high radial and axial loads and accommodates misalignment. The dynamic load rating of 325 kN characterises this bearing. The static load rating is 375 kN. The limiting speed is 5300 rpm. This variant features greatly increased radial clearance (C4). For heavy, hot-running arrangements the design quantity is not the initial clearance but what is left of it after fitting and heating.

Strongly increased clearance (C4) differs from the standard configuration in the initial radial play alone; the rolling geometry, the alignment capability and the load-carrying behaviour of the two-row roller set stay the same. The need arises where several consumers of that same play occur at once. On a tapered seating surface a heavy arrangement calls for a long drive-up distance so that the inner ring grips the shaft or the adapter sleeve securely, and every millimetre travelled expands the ring.

If the bearing position additionally runs under a sustained heat flow from the process side — on dryers, ovens, drums or hot-running drives — the inner ring expands more than the cooler outer ring and consumes further play. Were a standard clearance used in that situation, the roller set would go into preload before the plant had even reached its operating temperature.

The reverse side shows in the cold state: the bearing then runs with noticeable play, the load zone is narrow, and the most heavily loaded roller takes a larger share of the radial force than it would with a close clearance. At bearing positions with low load, vibration or frequent standstills this has to be checked, because a roller set that is too lightly loaded slides instead of rolling.

Rings and rolling elements are made of through-hardened standard bearing steel; above the usual operating temperature range the dimensional stabilisation of the material has to be considered as well. The open form leaves sealing and relubrication to the surrounding construction, which at high temperatures also carries part of the heat dissipation.