NTN - Plummer Blocks

Handling the Plummer Blocks and Bearings
(7) If it is difficult to tighten a large bearing by manual
force, use a hydraulic nut or ram for easier
assembly. (See Fig. 9.15.)
Fig. 9.12
Fig. 9.15
(8) Make sure the bearing clearance is as specified,
then bend one tab on the washer that corresponds
with the cutout on the circumference of the nut to
maintain the adjustment (Fig. 9.16). Do not loosen
the nut to allow the cutout to match the tab.
Fig. 9.13
(6) To tighten the nut, use a spanner wrench illustrated
in Fig. 9.14.
When tightening the nut with a hammer and a drift,
be sure that the chip from the drift does not enter
the bearing.
Fig. 9.16
(9) When a large bearing is installed to a shaft, its outer
ring will be deformed by its own weight into an
elliptical form. The clearance measurement at the
lowest point on a deformed bearing will be greater
than a true clearance. Remember that a radial
clearance value measurement at this point will result
in excessively large tightening allowance.
Fig. 9.14
(10) The adapter used on a large bearing whose bore
number is 44 or greater is a lock plate type (Fig.
9.17). For this arrangement, first tighten the nut,
then fit the lock plate into the cutout on the nut. In
this case too, do not loosen the nut to allow the
cutout to match the lock plate. Once the lock plate is
seated in the cutout, secure the adjustment with a
spring washer and a hexagonal nut.
27