NSK 2205 K-2RSTNG Pendelkugellager (25x52x18)

As a self-aligning ball bearing, this bearing compensates for misalignment and shaft deflection. This NSK bearing measures 25x52x18 mm and weighs 0.157 kg; the specification table carries the supplementary technical details. This variant features a contact seal. Sealed design, rings and balls in standard bearing steel, normal radial clearance.

The contact seal on both sides closes off the rolling chamber of the self-aligning ball bearing and thereby takes over two tasks from the adjacent construction: the grease charge stays with the rows of balls, and dust, fibres or moisture do not reach the raceways. That matches the typical application of this design exactly, since self-aligning ball bearings stand where bearing seats are not produced in one setup — on conveyors, blowers, agricultural machinery and textile machinery — and the same environment is usually the dusty one as well.

The design particularity lies in the alignment capability: because the inner ring unit swivels inside the outer ring, the position of the seal relative to its counterface changes with the misalignment; the permissible misalignment of the sealed version is therefore to be taken from the manufacturer's data and not carried over from the open variant.

Added to this is the frictional torque of the bearing lip, which generates heat and pushes the permissible speed below that of the open version of the same size, as well as the temperature and media limits of the seal material. The load-carrying properties remain unchanged: two rows of balls run on the common spherical outer raceway, the low conformity keeps the load rating below that of a rigid ball bearing of the same size, and axial forces are permissible only to a modest extent.

Rings and balls are made of through-hardened standard bearing steel; the normal radial clearance is matched to common fits and operating temperatures.