Page 503 - Rollingbearings

Designs and variants
NNCL design bearings NNC design bearings NNF design sealed bearings

• have three integral langes on the inner • have the same inner ring as NNCL and • comprise the 50 and 3194‥ series
ring and no langes on the outer ring NNCF design bearings • have a two-piece inner ring:
• have a retaining ring in the outer ring • have a two-piece outer ring: – held together by a retaining ring
between the roller rows to hold the bear- – held together by retaining elements, – with three integral langes
ing together which should never be loaded axially • have one integral central lange on the
The retaining ring should not be loaded – consisting of two identical outer ring outer ring
axially during operation parts with one integral lange on each • are used to locate the shaft axially in both
• can accommodate axial displacement of • are used to locate the shaft axially in both directions
the shaft relative to the housing in both directions • can accommodate tilting moments
directions because of the distance between the two
Alternative NNC design bearings may consist rows of rollers
of a one-piece outer ring with one integral • have an outer ring that is 1 mm narrower
NNCF design bearings lange and a lange ring than the inner ring
• do not require spacer rings between the
• have three integral langes on the inner inner ring and adjacent components, in
ring and one on the outer ring applications with a rotating outer ring
• have a retaining ring in the outer ring, on • have two snap ring grooves in the outer
the side opposite the integral lange, to ring:
hold the bearing together – to simplify mounting
The retaining ring should not be loaded – to save space axially
axially during operation This is especially valuable where the
• are used to locate the shaft axially in one bearing is mounted in/on an adjacent 6
direction and eventually to accommodate component, e g in rope sheaves
axial displacement of the shaft relative to (ig. 23)
the housing in the opposite direction • have a PUR contact seal on both sides,
itted in a recess on the inner ring shoulder
(ig. 22)
The seal lip exerts slight pressure
against the outer ring raceway
• are illed with a high-quality grease with
good rust-inhibiting properties (table 1,
page 503)
For additional information about
greases, refer to Lubrication, page 109
• can be supplied open and without grease,
for applications where oil lubrication is to
be used
If a small quantity of bearings without
Fig. 23 seals is required, the seals can be removed
NNF design sealed bearing in a rope and the bearings can be washed prior to
sheave mounting

Relubrication

For many application conditions, NNF design
sealed bearings do not require relubrication
and can be considered relubrication-free
However, if they operate in a moist or con-
taminated environment, or if speeds are
moderate to high, relubrication may be
necessary (Estimating the relubrication interval
for grease, page 111) The bearings can be
relubricated via lubrication holes in both the
inner and outer rings

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