Page 702 - SKF-bearing-housings

Inch roller bearing units SYE, SYR, FYE and FYR series

Table 1 provides an overview of the charac- plugs are identified by the designation suffix Y.
teristics and suitability of each sealing solu- For information about the permissible length
tion. Details are provided in the following text. of the shaft end, contact the SKF application
This information should be used as a guideline engineering service.
and does not substitute for testing a seal in its
application.

TriGard seals
TriGard seals are standard with inch roller
bearing units. These acrylonitrile-butadiene
rubber (NBR) seals have the outside surface
and seal lips vulcanized to a sheet steel insert.
The seal consists of two lips that make contact
with the mounting collar or bearing inner ring,
and a third, non-contact lip, to protect the seal
lips from coarse contaminants. The rubber
coated outside circumference secures the seal
in the housing and enhances the sealing effect.

Labyrinth seals
As labyrinth seals do not generate friction,
bearing units fitted with these seals are cap-
able of relatively high speed operation.
For SKF ConCentra units, the labyrinth is
created with three sheet steel rings. Two rings
are fixed to the mounting collar or back-up
collar and rotate with the shaft to act as flin-
gers. The third ring is secured in the housing
bore.
For collar-mount units, the labyrinth is cre-
ated with two sheet steel rings. One ring is
pressed onto the extended inner ring and
rotates with the shaft, acting as a flinger. The
other ring is secured in the housing bore.

Radial shaft seals (garter spring seals)
Collar-mount units can be supplied with radial
shaft seals on both sides, on request. The
seals are made of acrylonitrile-butadiene rub-
ber (NBR) and have no metal reinforcement.
They sit firmly in the housing bore providing a
static seal. The spring-loaded seal lip provides
a dynamic seal against the inner ring shoulder.

End plugs
Bearing units mounted at the end of a shaft
should have an end plug (end cover). End plugs
for units up to 2 15 /16 inches are plastic, while
larger sizes are steel. Bearing units with end

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