Page 671 - SKF-bearing-housings

Sealing solutions

Sealing solutions able of relatively high speed operation. The
labyrinth is created with three sheet steel
SKF ConCentra roller bearing units in the rings. Two rings are fixed to the mounting col-
SYNT series are available with different seal- lar / back-up collar. Both rotate with the shaft
ing solutions († fig. 7): to act as flingers. The third ring is secured in
the housing bore.
• double-lip seals
• labyrinth seals
• heavy-duty radial shaft seals Heavy-duty radial shaft seals
• end covers Heavy-duty radial shaft seals with an auxiliary
lip provide superior protection against con-
Bearing units in the FYNT series are produced taminants. These rugged and robust seals
standard with double-lip seals. End covers are have a steel insert that is encased in acryloni-
also available, but must be ordered separately. trile-butadiene rubber (NBR). The primary
Table 1, page 668 provides an overview of seal lip can maintain its sealing ability even if
the characteristics and suitability of each seal- there is excessive wear. An auxiliary dust lip
ing solution. Details are provided in the follow- provides added protection against coarse
ing text. This information should be used as a contaminants.
guideline, and does not substitute for testing a
seal in its application.
End covers
Bearing units mounted at the end of a shaft
Double-lip seals should have an end cover. These are made of
Double-lip seals are made of acrylonitrile- plastic and can be snapped easily into the
butadiene rubber (NBR) that is vulcanized onto recess of the housing bore.
a stamped steel insert. The steel insert en ables Details of the permissible length of the shaft
the outside surface of the seal to sit firmly in end are provided in table 2 on page 669.
the housing bore, providing a static seal. The
seal has an auxiliary lip to protect against
coarse contaminants.

Labyrinth seals
As labyrinth seals do not generate friction,
bearing units fitted with these seals are cap-
Fig. 7
Seals for SKF ConCentra roller bearing units

16
Double-lip seal Labyrinth seal Heavy-duty radial End cover
shaft seal

667