NSK 2207-2RSTNGC3 Pendelkugellager (35x72x23)

As a self-aligning ball bearing, this bearing compensates for misalignment and shaft deflection. For this NSK bearing, 35x72x23 mm and a weight of 0.405 kg apply; the specification table holds the further technical particulars. This variant features a contact seal and increased radial clearance (C3). Two rows of balls on a common spherical raceway, a contact seal on each side, and the larger radial reserve of class C3.

In this version the sealing and the clearance class engage with one another through the heat balance of the bearing position. The contact seal on both sides keeps the grease charge with the rows of balls and contamination away from the raceways; in return its lip rubs on the counterface and releases heat in addition to the rolling friction.

That heat stands in the same calculation as a tight inner ring seat, a drive-up distance on an adapter sleeve or a warm adjacent construction — it expands the inner ring more than the outer ring and reduces the mounted radial play. Increased clearance (C3) sets the initial play correspondingly higher, so that in warm service a residual play remains within the intended range and the ball set is not braced.

For the layout, three quantities therefore have to be considered together: the type of seat with its expansion of the inner ring, the temperature gradient between the rings, and the speed, which together with the frictional torque of the seal determines the operating temperature. The permissible speed of this version is tied to the seal, as are the limits for operating temperature and media resistance.

The alignment capability is retained, but the permissible misalignment comes out smaller than in the open version because of the seal carried along. Rings and balls are made of through-hardened standard bearing steel, and the load rating stays tied to the low conformity of the spherical outer raceway.