Xylem IMDWT R02 Model DWT Deep Well Turbine Pumps - Manual (Page 17)

17
Never check motor rotation with the drive
coupling in place. The bore clearance
between the drive coupling and the pump shaft O.D.
is so close that should the motor spin with this shaft
stationary, galling and locking together is very likely to
take place.
11. Install motor drive coupling. (Be sure to line up the
match mark made at step 6.) Inserting the ratchet
pins if a non-reverse ratchet is used. Match the
coupling lugs with corresponding holes in motor.
Tighten hold down bolts evenly, making sure driver
coupling is properly seated in the register fit.
12. Fit gib key (730) into keyway, by filing if necessary,
to where there is a snug but sliding fit. This key
must be able to be removed by gentle leverage with
a screwdriver under it.
13. Be careful that the gib key (730) is not too high so
as to hold up the adjusting nut (604) from seating
on the drive coupling. If it is, cut off some length of
the key.
14. Install adjusting nut (604) to hand tight.
COMBINATION ENGINE AND MOTOR DRIVES
1. On combination drivers, the motor is invariably on
top with a projecting head shaft extension.
2. Follow all procedures outlined on page 15, except
that the motor must be lowered over this extended
head shaft and great care must be taken to center
it exactly so as not to bump or miss-align the shaft
while the motor is being lowered into place.
3. There are several methods of running engines
without electric motors and vice versa, requiring
simple adjustment to the combination drive, but
they are too numerous to mention here and can be
obtained from the gear manufacturers instructions
included with the shipment.
IMPELLER ADJUSTMENT FOR ALL
HOLLOW SHAFT DRIVES
NOTE: Shaft adjustment up or down is accomplished by
turning the adjusting nut (604) Figure 10.
NOTE: There are five holes in the adjusting nut and
only four in the motor coupling. See Figures 11.
1. With shafting all the way down and the impellers
resting on their seats, turn the adjusting nut (604)
in counterclockwise direction, thus lifting the shaft,
until the impellers just clear their seats and the
shaft/motor turns free by hand. This removes all
deflection from the shaft. (This is the “Shaft Pull-up
in the Chart on page 14.)
2. For enclosed impellers, if pump setting is 200 ft. or
less, make another two turns on the adjusting nut
for the first 100 ft. (3 turns for 12 thread/inch shaft)
and one additional turn for each additional 50 ft.
Line-up one of the holes in the adjusting nut with
the nearest hole in the driver coupling. Insert the
capscrew in the hole and tighten it.
CAUTION
NOTE: 1.00" and 1.18" diameter shafts are 12 thread
per inch (tpi), 1.50" through 2.44" are 10 tpi, all
larger sizes are 8 tpi.
For pump setting over 200 ft., continue to turn the
adjusting nut until impellers reach the top of bowls
(resistance is felt when impellers rub against the top
of bowls.) The number of turns to reach the top
of the bowl should equal the total lateral obtained
during bowl assembly installation as recommended
in Paragraph 2 on page 10. If the lateral measured
at the adjusting nut is less than that recorded
previously, check the headshaft to make sure that
the adjusting nut has not run out of threads and
that the keyway is long enough. Also, check the
shaft coupling or water slinger to make sure that
neither one is being pulled up against the bottom of
the driver base. Now, lower the impellers (turn the
adjusting nut clockwise) by 30% of the total lateral.
Line-up one of the holes in the adjusting nut with
the nearest hole in the driver coupling. Insert the
capscrew in the hole and tighten it.
For pump setting over 500 ft., consult factory for
special instruction.
3. For Open Impellers, Align hole “A” in the adjusting
nut (604) and hole “C” in the driver coupling (See
Figure11) or whatever similar holes are in like
position. If care is exercised, this will give an initial
impeller clearance of 0.001” to 0.003” depending
on shaft size or the pitch of the thread.
4. Insert capscrew into hole “B” provided these are
the nearest matching holes for counterclockwise
rotation of adjusting nut, turn adjusting nut
counterclockwise until holes “B” and “D” line up.
This gives 1/20 of a turn which is 0.004” on 12 tpi
or 0.005” on 10 tpi shaft.
5. Normal impeller clearance
for the open impeller is
considered to be 0.015”
for the first 10 ft. of the
column length and 0.010”
additional clearance for
each 10 ft. of length
thereafter. This can be
reduced in some instances
where is necessary, but
should not be attempted
without consulting the
factory or a factory
serviceman if present.
Figure 12
(604) ADJUSTING NUT
LOWER IMPELLER
RAISE IMPELLER
MOTOR COUPLING
ROTATION
A
B
G
D
H
C
E
F