Sealing solutions

With the exception of bearings designated with a BS2- prefix, the boundary dimensions of sealed spherical roller bearings are in accordance with ISO 15. Bearings with a BS2- prefix, for example BS2-2214-2RS/VT143, are based on 222 E or 223 E series bearings, but are slightly wider to accommodate the seals.

Sealed spherical roller bearings have the same features and internal design as basic design spherical roller bearings and are available with a cylindrical bore as standard. Some sizes are also available with a tapered bore or can be supplied with a tapered bore on request.

Sealed spherical roller bearings are supplied grease lubricated and should not be washed. For many application conditions, the bearings do not require relubrication and can be considered relubrication-free (→ Grease life for sealed bearings).

SKF does not recommend heating sealed spherical roller bearings above 80 °C (175 °F) during the mounting process. However, if higher temperatures are necessary, make sure that the temperature does not exceed the permissible temperature of either the seal or grease, whichever is lowest.
Contact seals
Sealed spherical roller bearings have a contact seal reinforced with a sheet steel insert, fitted on both sides. They can also be supplied with a seal on only one side. The bearings can be fitted with seals made of one of the following materials:
  • NBR (designation suffix CS or RS)
  • HNBR (designation suffix CS5 or RS5)
  • FKM (designation suffix CS2)

RS seals are fitted in a recess on the outer ring (fig. 1) and seal against the inner ring. CS seals are fixed by a retaining ring (fig. 2).

Greases for sealed bearings
Sealed spherical roller bearings are filled as standard with SKF LGEP 2 grease. Bearings filled with other SKF greases can be supplied on request. Technical specifications are listed in table 1.

For additional information about greases, refer to Lubrication.

Grease life for sealed bearings

The grease life for sealed bearings is presented as L10, i.e. the time period at the end of which 90% of the bearings are still reliably lubricated. It depends on the load, operating temperature and speed factor. It can be obtained for bearings with standard SKF LGEP 2 grease (designation suffix VT143) from the diagrams. Diagram 1 is valid for light load (P = 0,067 C), diagram 2 for normal load (P = 0,125 C). The grease life is valid under the following operating conditions:

  • horizontal shaft
  • inner ring rotation
  • operating temperature within the green temperature zone of the grease (→ table 1)
  • stationary machine
  • low vibration levels
  • load ratio Fa/Fr ≤ e (→ product table)
  • rotational speed below the limiting speed (→ product table) and below the limits listed in table 2

For other operating conditions, the grease life can be estimated by multiplying the relubrication interval for open bearings (→ Relubrication) by a factor of 2,7.

Relubrication of sealed bearings
When the required service life is longer than the grease life, the bearings may require relubrication. A suitable grease quantity to relubricate sealed bearings can be obtained using

Gp = 0,0015 D B

grease quantity [g]
bearing outside diameter [mm]
bearing width [mm]

The grease should be applied slowly through the lubrication holes in the outer ring, preferably while the bearing is rotating to avoid damaging the seals. SKF recommends relubricating with the same grease as the initial fill.


Bearings with designation suffix CS2 have seals made of FKM (fluoro rubber). FKM exposed to an open flame or temperatures above 300 °C (570 °F) is a health and environmental hazard! It remains dangerous even after it has cooled.

Read and follow the safety precautions under Seal materials.

SKF logo