Page 44 - Y-bearing-units

Design of Y-bearing arrangements

Misalignment Fig. 5

Y - b e a r i n g u n i t s c a n a c c ommodate initial mis-
alignment († fig. 4) of up to:
• 5° when relubrication is not required
• 2° when relubrication is required
Additionally, operational shaft deflections of
a few minutes of arc can be permitted.
Y-bearing units with pressed steel housings
cannot accommodate misalignment once the
attachment bolts have been fully tightened,
unless they are equipped with a rubber seating
ring († page 45).

Support surfaces

To maximize the service life of Y-bearing units,
the support surfaces must be manufactured
with:
• a roughness of R a ≤ 12,5 µm
• a flatness (planicity) tolerance to IT7 or IT8

When a heavy load, parallel to the housing base,
acts on a Y-bearing unit († fig. 5) SKF recom-
mends doweling the housing to the support
surface. The position and size of the holes for
the dowel pins are listed in the relevant product
sections.

Fig. 4

5°

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