SKF - Industrial Shaft Seals

Additional design features
Spring connections
There are different ways to connect the stainless
steel garter springs of HS and HSF seals. A
threaded spring connection († fig. 54a) is used
for all HSF seals unless otherwise specified and
for the solid HS4 and HS5 seals as well as the
split HS6 and HS8 seals for shaft diameters
≤ 455 mm (18 in.). A hook-and-eye spring connection
(† fig. 54b) is used for HS6 and HS8
seals for shaft diameters > 455 mm (18 in.). All
HS7 seals feature the special control-wire connection
(† fig. 54c), available only for these
seals.
Spacer lugs
Spacer lugs are available for all metal-cased
designs to separate seals in tandem or back-toback
arrangements to provide space for sealing
lip lubrication († fig. 55).
Traditional fixed-width lugs for metal-cased
HDS seals are 9,5 mm (0.375 in.) in diameter
and are available in widths from 3,2 mm
(0.125 in.) to 12,7 mm (0.5 in.) in increments
of 1,6 mm (0.063 in.). The fixed-width lug is an
available option for all metal-cased seals.
All standard adjustable lugs are 9,5 mm
(0.375 in.) in diameter and 9,5 mm (0.375 in.)
in width. They can be adjusted to smaller widths
in 1,6 mm (0.063 in.) increments by removing
the steel washers. The lugs may also be removed
entirely. Longer, adjustable lugs, with a width of
12,7 mm (0.5 in.), are available on request,
however, it can be more difficult to reduce their
width.
Certain small seal cross sections may require
special small diameter lugs, 5,3 mm (0.210 in.),
with a width range of 1,6 to 3,2 mm
(0.063 to 0.125 in.).
The lugs are placed around the heel of the
seal in four, six or eight equally spaced locations,
depending on the seal outside diameter
(† table 17).
Fixed-width lugs are available for HDL seals
on request.
Spring connections
a
b
c
Spacer lugs
Number of spacer lugs needed
Spacer Housing bore diameter
lugs
from incl. from incl.
– mm in.
4 762 30
6 762 1 143 30 45
8 1 143 45
Fig. 54
Fig. 55
Table 17
2
211