MR−05740
PA SERIES PUMPS
MAINTENANCE & REPAIR
PAGE C − 15
Clean the bearings thoroughly in
fresh
cleaning
solvent. Dry the bearings with filtered compressed
air and coat with light oil.
Bearings must be kept free of all dirt and
foreign material. Failure to do so will great-
ly shorten bearing life.
Do not
spin dry
bearings. This may scratch the balls or
races and cause premature bearing fail-
ure.
Rotate the bearings by hand to check for rough-
ness or binding and inspect the bearing balls. If ro-
tation is rough or the bearing balls are discolored,
replace the bearings.
The bearing tolerances provide a tight press fit
onto the shaft and a snug slip fit into the bearing
housing. Replace the bearings, shaft, or bearing
housing if the proper bearing fit is not achieved.
If bearing replacement is required, remove the
snap ring (13) and use a bearing puller to remove
the inboard and outboard bearings (3 and 8) from
the shaft.
Shaft and Bearing Reassembly and Installation
(Figure C−5)
Inspect the shaft for distortion, nicks or scratches,
or for thread damage on the impeller end. Dress
small nicks and burrs with a fine file or emery cloth.
Replace the shaft if defective.
Clean and inspect the bearings as indicated in
Shaft And Bearing Removal And Disassembly
.
To prevent damage during removal from
the shaft, it is recommended that bearings
be cleaned and inspected
in place
. It is
strongly
recommended that the bearings
be replaced
any
time the shaft and bear-
ings are removed.
NOTE
The inboard bearing (3) comes from the manufac-
turer with a retaining ring installed on the bearing
O.D. This retaining ring
must
be removed prior to
installation.
The bearings may be heated to ease installation.
An induction heater, hot oil bath, electric oven, or
hot plate may be used to heat the bearings. Bear-
ings should
never
be heated with a direct flame or
directly on a hot plate.
NOTE
If a hot oil bath is used to heat the bearings, both the
oil and the container must be
absolutely
clean. If
the oil has been previously used, it must be
thor-
oughly
filtered.
Heat the bearings to a uniform temperature
no
higher than
250
_
F (120
_
C), and slide the bearings
onto the shaft, one at a time, until they are fully
seated. This should be done quickly, in one con-
tinuous motion, to prevent the bearings from cool-
ing and sticking on the shaft.
After the bearings have been installed and allowed
to cool, check to ensure that they have not moved
away from the shaft shoulders in shrinking. If
movement has occurred, use a suitably sized
sleeve and a press to reposition the bearings
against the shaft shoulders.
If heating the bearings is not practical, use a suit-
ably sized sleeve, and an arbor (or hydraulic) press
to install the bearings on the shaft.
When installing the bearings onto the
shaft,
never
press or hit against the outer
race, balls, or ball cage. Press
only
on the
inner race.
Secure the outboard bearing (8) to the shaft with
the retaining ring (13).
Apply a light coating of oil to the lip of the inboard oil
seal (17) and press it into the bearing housing with
the lip positioned as shown in Figure C−5. Press
the oil seal into the housing until the face is
just
flush
with the machined surface on the housing.
