HDSA, HDSB and HDSC seals
HDSA (fig 1), HDSB (fig 2) and HDSC (fig 3) seals are designed with an elastomeric auxiliary lip in addition to the sealing lip. They are generally used where additional protection from contaminants is needed and where there is insufficient space for more than one seal.
The chamfer on the auxiliary lip of an HDSA seal faces the sealing lip, enabling easier shaft installation from the sealing lip direction. The chamfer of the auxiliary lip of HDSB seals faces away from the sealing lip, enabling easier shaft installation from the other direction. The disadvantage is, however, a slightly reduced exclusion ability. The auxiliary lip of HDSC seals is located in front of the sealing lip with its chamfer facing the sealing lip to provide maximum exclusion ability.
HDSA2, HDSB2 and HDSC2 seals are designed with an SKF Springcover, while HDSA1, HDSB1, HDSC1 seals are designed without an SKF Springcover (fig 4).
HDSA, HDSB and HDSC seals can also be designed with an elastomer applied to the metal outside diameter (fig 5).
HDSA, HDSB and HDSC seals are available with sealing lips made of nitrile rubber, SKF Duralip, SKF Duratemp or SKF Duralife. For shaft diameters up to 1 200 mm (47 in.), the standard auxiliary lip is made of SKF Duralip.
These seals are available for all shaft diameters within the ranges listed in the table. A selection of available sizes is listed in the product table. Contact your SKF sales representative for additional information regarding availability.