SKF - Rolling Bearings

Relubrication
The relubrication interval t f may be extended
at temperatures below 70 °C (160 °F) if the
temperature is not close to the lower temperature
performance limit LTPL († diagram 1,
page 245). SKF does not recommend extending
the relubrication interval t f by more than
a factor of two.
Do not extend the obtained t f values
(† diagram 4, page 256) for full complement
bearings or thrust roller bearings. Moreover, it
is not advisable to use relubrication intervals
in excess of 30 000 hours.
particles. Liquid contaminants such as water
and/or process fluids also require a reduced
relubrication interval. In case of severe contamination,
continuous relubrication should
be considered.
Vertical shafts
For bearings on vertical shafts, the intervals
obtained from diagram 4 († page 256)
should be halved.
The use of an effective seal, shield or baffle
plate is a prerequisite to prevent grease leaking
from the bearing arrangement.
Vibration
Moderate vibration does not have a negative
effect on grease life. However, high vibration
and shock levels, such as those in vibrating
screen applications, cause the grease to
churn. In these cases, the relubrication interval
should be reduced. If, during operation,
the grease becomes too soft, use a more
mechanically stable grease, e.g. SKF LGHB 2
or grease with higher stiffness up to NLGI 3.
Outer ring rotation
In applications where the outer ring rotates,
the speed factor A is calculated differently. In
this case, use the bearing outside diameter D
instead of d m . The use of an effective seal is a
prerequisite to avoid grease leakage.
In applications where there are high outer
ring speeds (i.e. > 40% of the reference speed
listed in the product tables), greases with good
oil bleeding properties should be applied.
For spherical roller thrust bearings with a
rotating housing washer, oil lubrication is
recommended.
G
Contamination
In applications where the ingress of solid contaminants
is an issue, more frequent relubrication
than indicated by the relubrication interval
is necessary. Relubrication reduces the
level of contamination while reducing the
damaging effects caused by overrolling the
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