Page 360 - SKF-bearing-housings

Split plummer block housings SONL series

Housing variants circulating oil lubrication system, SKF recom-
mends using SONL .. RA housings. These
In addition to standard design SONL plummer housings are designed for bearings that are
(pillow) block housings, a number of variants lubricated from the side and require a slightly
are also available. Variants include housings higher oil level than spherical roller bearings.
made of different materials, different bearing In SONL .. RA housings, the holes that con-
seat tolerance classes and additional tapped nect the two halves of the oil sump are pos-
holes for circulating oil lubrication systems. itioned higher than in standard housings. This
enables oil to reach the rolling elements of the
bearing († fig. 6).
Housing material For additional information, refer to Using
For applications where extra strength is circulating oil lubrication with CARB and self-
needed, SONL housings are also available aligning ball bearings on page 367.
in spheroidal graphite cast iron.

Sealing solutions
Bearing seat tolerance
SONL housings can be supplied with different SONL housings are equipped with non-contact
bearing seat tolerance classes, e.g. for appli- labyrinth seals († fig. 7). These seals retain
cations prone to vibration or with rotating the lubricating oil and prevent contaminants
outer ring load. from entering the housing. The oil retaining
For additional information, contact the SKF effect is enhanced by oil traps that return oil
application engineering service. that has passed through the labyrinth back to
the oil reservoir. Table 1 provides an overview
of the seal characteristics and suitability. This
Housings for circulating oil information should be used as a guideline and
lubrication systems does not substitute for testing the seal in its
In applications where CARB toroidal roller and application.
self-aligning ball bearings are lubricated by a A labyrinth seal consists of a shaft sleeve
and a labyrinth ring, to form a multi-stage
Fig. 6
labyrinth. The sleeve has a clearance fit on
SONL .. RA housing the shaft while the labyrinth ring is stationary
and mounted in the housing with an O-ring.
To guide the oil pick-up ring, one shaft sleeve
is provided with a groove.
The shaft sleeve can be locked onto the
shaft in different ways:
• Shaft sleeves for bearings on an adapter
sleeve (TSO 5..) are locked by grub screws
in the shaft sleeve.
• Shaft sleeves for bearings on a cylindrical
seat (TSO 2..) must be locked by an adapter
ring, end plate or similar component (not
supplied by SKF) on the shaft. Details for
locking are shown in product table 7.3
(† page 378).

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