Xylem MPV - Manual (Page 89)

Installation, Operating and Maintenance Instruction
Model MPB, MPV
MPB 100-english page 85 Revision 02
Article No 771074115 Issue 01/2010
Pull the coupling half (7/M) off the motor shaft with
a withdrawing screw.
Replace the motor bearing according to the repair
manual of the motor.
Assembly
Mount the coupling half (7/M) onto the motor shaft
as described in Section 5.3.2 "Coupling – MPV
Design) and tighten the coupling fastening screw
(S9).
Then reassemble the motor in reverse of the
disassembly order and reconnect the coupling
halves with the hexagon head screws (S8).
8.5.2 Replacing the Rolling Bearing – MPV Design
For the associated sectional drawing, see the
appendix.
Disassembly
Remove the motor.
Remove the thrower (73M) and put the thrower
(73P) back in place.
Screw off nuts (M1) and nuts (M5), loosen the
bearing cover (12) from the bearing pedestal (8)
and slide downward.
Lift away the bearing pedestal (8) upward (a slight
axial pounding on the bearing pedestal (8) will
make it easier to pull off)
After removing the bearing pedestal (8), the
shaft will move freely in the axial direction
(approx. 3 – 4 mm). Standard shaft seals can
take up this play without impairing their function.
For special shaft seals (e.g. cartridge seals),
please follow the seal operating instructions.
Unscrew shaft nuts (50) (sickle spanner). The
shaft nut has a securing device to prevent it
coming loose.
If this securing device is no longer adequate, the
nut must be replaced.
Remove roller bearings (K) with the withdrawing
screw.
Check the surface of the shaft for damage, grind
away any furrows.
Assembly
Clean the fitting surfaces between the bearing
pedestal (8) and pressure casing (4) and coat
them with lubricant.
Pre-heat the new bearing (K) – paired angular ball
bearing in x arrangement – (max. 80°C) and slide
it onto the shaft (24).
Paired angular ball bearings in X arrangement
Tighten shaft nut (50) while the bearing is still hot.
Fill approximately 60% of the space in the roller
bearing (K) with grease (when the bearing has
cooled down).
Put the bearing pedestal (8) in place and initially
only loosely screw on the nuts (M1).
Screw the bearing cover (12) to the bearing
pedestal (8) (nuts (M5)).
Coat the counter-rotation surfaces of the thrower
sealing lip on the bearing cover (12) and on the
bearing pedestal (8) with grease.
Put the throwers (73P and 73M) in position
(groove in the spacer sleeve (72) for thrower
(73P)).
Tighten the nuts (M1) (see appendix for torque).
Turn the shaft (24) and check for easy motion.
8.6 Replacing the Slide Bearing
This section describes the replacement of the slide
bearing in the suction casing (3).
For the associated sectional drawing, see the
appendix.
Disassembly
Place the pump vertically on the motor stool (11,
MPB design) or the bearing pedestal (8, MPV
design).
Screw off the nuts (M1), remove the casing
screws (25)
Remove the suction casing (3) (a slight pounding
on the suction casing (3) makes it easier to pull
off)
Screw off the impeller nuts (28), remove the
washer (29)
Pull off and replace the bearing sleeve (23).
Inspect the shaft for surface damage, grind off any
remaining furrows.
Remove the bearing bush (21) from the suction
casing (3) (screw off).
Assembly
Clean the fitting surfaces between the stage
casing (60) and the suction casing (3) and coat
them with lubricant.
Slide the new bearing sleeve (23) onto the shaft
(24).
Secure the bearing sleeve (23) with washer (29)
and impeller nuts (28).
Tighten the first nut (28), then turn it back approx.
¼ turn, secure with the locknut.
Press the bearing bush (21) into the suction
housing (3).
Put the suction casing (3) in place, screw in the tie
bolts (25) and tighten the nut (M1) (see the
appendix for the torque).
Turn the shaft (24) and check for easy motion.
8.7 Replacement of the shaft sleeve with a
packing gland / Replacement of the
mechanical seal
This section describes the replacement of the shaft
sleeve for designs with a packing gland or the
replacement of the mechanical seal.