10
19
The internal circulation flow path through the bearings and the
magnetic coupling is supplied with discharge pressure and
returns to discharge pressure. The differential pressure required
to do this is supplied by an impeller built into the outer end of
the inner magnet assembly (175). This flow provides cooling to
the magnets (175) and the containment shell (150) and also
lubrication as well as cooling to the bearings (182), journal
sleeves (200) and thrust collars (210).
The flow (as shown in the drawing above) is fed from the
perimeter of the impeller (3) and flows through a passage in
the casing cover (22) to an area between the bearings (182).
The flow splits at this point with part of the flow proceeding
between the front bearing (182) and journal (200), past the
front thrust collar (210), through the balance holes in the
impeller (3) back to the suction of the pump. The rest of the flow
passes through the bearing spacer (17) and the pump shaft
(29) to the end of the inner bearing assembly (175) where the
impeller blades on this assembly increase the pressure, forcing
the pumpage between the inner magnet assembly (175) and
the containment shell (150), through a passage in the casing
cover (22) back to the perimeter of the impeller (3). A small
amount of this flow is diverted before it can enter the passage
in the casing cover (22) and passes between the rear bearing
(182), thrust washer (210) and journal (200) and then returns
to the bearing spacer (17) where it merges with a new supply
of internal circulation flow.
INTERNAL CIRCULATION FLOW PATH
To check the offset alignment, mount the dial indicator as
above except with the indicator button on an outside diameter
of the stationary coupling hub. Rotate the shaft on which the
dial indicator is mounted, allowing the indicator button to ride
on the outside diameter of the stationary hub. The indicator
dial movement will show the difference in the center locations
of the two shafts. Good practice suggests alignment to within
0.002" T.I.R.
Angular and offset alignment is adjusted by placing thin metal
shims under the driver mounting feet to bring the drive into
exact alignment with the bolted down pump.
If misalignment
is of major proportions, the baseplate has been improperly
installed on the foundation and must be releveled before
proceeding with alignment.
Moderate alignment adjustments may be made by using the
jack bolts provided on some frame feet. Loosen the frame foot
hold-down bolt(s) and the jack bolt lock nuts. Adjustments of
the jack bolts may then be made.
After each change, by shims or jack bolts, it is necessary to
recheck both angular and offset alignment of the coupling.
After the pump and driver are aligned, tighten all hold-down
and jack bolt lock nuts and then recheck alignment.
Allowable error of shaft alignment is somewhat dependent on
the coupling type. However, the closer the running alignment,
the better the running life will be, as any misalignment applies
loads to both the pump and motor. The greater the misalign-
ment, the greater the load.
GROUTING THE BASEPLATE
Channel type baseplates are made with open ends to allow
easy grouting and do not require grouting holes in the base-
plate.
Do not grout the baseplate until the alignment explained
under “Baseplate Mounting and Alignment,” steps 1 through 4
has been completed.
Fill the entire void under the baseplate
with grout and firmly embed the baseplate edges.
I
NDICATOR
S
ETUP TO
R
EAD
O
FFSET
M
ISALIGNMENT
I
NDICATOR
S
ETUP TO
R
EAD
A
NGULAR
M
ISALIGNMENT
