SKF - Rolling Bearings

Designs and variants
1
Shields
Bearings with shields are primarily intended
for applications where the inner ring rotates.
Shields are fitted in the outer ring and do not
make contact with the inner ring, but form a
narrow gap with it. Shields are made of sheet
steel. For stainless steel bearings, stainless
steel is used.
Depending on the bearing design, series and
size, SKF supplies shields in different designs.
Shields identified by the designation suffix Z
typically have an extension in the shield bore
to form a long, narrow gap with the inner ring
shoulder († fig. 6a). Some shields do not
have the extension († fig. 6b). The bore of a Z
shield on some stainless steel deep groove ball
bearings can extend into a recess on the inner
ring († fig. 6c).
Shields identified by the designation suffix
ZS are available for stainless steel bearings
only. These shields are fixed in the outer ring
by a retaining ring († fig. 6d) and may extend
into a recess on the inner ring.
Non-contact seals
Bearings with non-contact seals can be operated
at the same speeds as bearings with
shields, but with improved sealing effectiveness.
The seals form an extremely narrow
gap with the inner ring shoulder († fig. 7).
Non-contact seals are made of oil and wearresistant
NBR that is reinforced by a sheet
steel insert.
SKF deep groove ball bearings with a noncontact
seal on one or both sides are identified
by the designation suffix RZ or 2RZ. Noncontact
seals are available for single row deep
groove ball bearings only.
Some stainless steel bearings are available
with non-contact seals on request. The exact
seal design may differ from the illustration
(† fig. 7).
RZ
Fig. 7
Fig. 6
a b c d
Z Z Z ZS
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