Page 52 - Y-bearing-units

Lubrication and maintenance

Relubrication intervals

The relubrication interval t f can be estimated
from diagram 1 as a function of the rotational
speed n (r/min), the bearing mean diameter
d m († table 2) and the operating temperature
(°C).
The recommended intervals correspond to a
time when 90% of the bearings are still reliably
lubricated, and represent L 10 grease life. When
the L 10 grease life is equivalent to or higher than
the rating life of the Y-bearing, the bearing is
considered to be lubricated for life and relubri- Table 2
cation is not required. Bearing mean diameter d m
The intervals obtained from diagram 1 are
valid for Y-bearings and Y-bearing units filled
with the standard high quality long lasting
mineral oil based grease, as well as for food-
grade grease:
d m d m
• on horizontal shafts
• in stationary machines
• P ≤ 0,05 C

If operating conditions differ, reduce the relu-
brication intervals obtained from diagram 1 as
follows:
1)
Bearing size Bearing mean diameter
d m
• on vertical shafts by 50%
• at heavier loads, e.g. at P > 0,10 C, – mm
by roughly 50%
03 28,5
04 33,5
In severe, very dirty or damp environments, 05 39

more frequent relubrication might be necessary. 06 46
When the operating temperatures are constantly 07 53,5
60
08
below 40 °C, the grease life is shortened
because oil separation is reduced. 09 65
70
10
Vibration can have a negative influence on 11 77,5
grease life too. The extent cannot be quantified 12 85
exactly, but it can be noticeable if the normal 13 92,5
operating temperature increases. 14 97,5

The values for reducing the relubrication 15 102,5
intervals are estimates. If in doubt, contact the 16 110
117,5
17
SKF application engineering service.
In cases where machines and equipment are 18 126
used for a limited period of time, SKF recom- 20 141
mends relubricating each bearing at the end of
the operational period, i.e. immediately before
being laid up.
1) For example: bearing size 06 includes all bearings based
on a Y 206 bearing, such as YAR 206-101-2F,
YAR 206-102-2F, YAR 206-2F, YAR 206-103-2F,
YAR 206 104¬ 2F
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