Series MNK pedestal group 4
Page
18
9230-003-en
Revision 19
TM 10458
Edition 06/2022
♦
Using the flat pivot point on the threaded rods and
an open-jaw wrench (size 13), push the slide-in unit
out of the lantern chamber. The threaded rods must
be turned evenly and alternately.
Caution ! Magnetic forces!
Risk of accident !
♦
Transport the drive unit using a crane. The ring bolt
on the bearing pedestal flange can be used for this
purpose.
♦
Position the rest of the slide-in unit vertically with the
impeller facing down.
♦
Remove screws
901/10
and lift off lantern
344
, can
159
and can insert
158
.
♦
Clamp the plain bearing pedestal
339
with the seal-
ing surfaces in a vice.
It is imperative to use rubberised
clamping jaws so that the plastic sealing
surfaces are not damaged.
♦
Undo impeller
230
and inner magnet assembly
859
by turning them in opposite directions.
Right-hand
thread
!
Either two strap wrenches or, even better,
appropriate special tools (see Assembly aids in
Section 11.3
) are used for this purpose.
With magnetic drives >400 Nm the use of the spe-
cial tool is generally recommended.
♦
The inner magnet assembly
859
is released from
the pump shaft
211
. The pump shaft is pulled out
with the remaining part of the plain bearing pedestal
339
.
♦
This operation must be performed carefully as plain
bearing parts made of silicon carbide may be re-
moved unintentionally.
Make sure that no parts of the plain bear-
ing fall. Silicon carbide is fragile.
♦
An appropriate Richter jig can be used to remove
the bearing bushes
545/1
and
545/2
. See as-
sembly aids in
Section 11.2
.
♦
The can
159
and can insert
158
should only be sep-
arated if one component has to be replaced. The
separation process can be simplified by cooling the
unit to approx. 5 °C.
♦
With a vacuum-tight design it is not possible to sep-
arate the can insert as it and the can are glued to-
gether.
7.6.2 Dismantling drive unit Long life
grease lubrication
♦
Remove the cylinder screw
914/5
with toothed lock
washer
934/4
and pull off the drive magnet assem-
bly
858
of the drive shaft
213
. For this purpose, do
not use any magnetisable tools if at all possible.
Caution ! Magnetic forces!
Risk of accident !
♦
Remove hex. socket screws
914/6
and pull off the
rear bearing cover
361
.
♦
Remove wavy spring washer
953/1
.
♦
Pull or push the drive shaft
213
with the rolling bear-
ings
321/1
and
321/2
out of the bearing pedestal
330
in the direction of the motor.
♦
To change the rolling bearings
321/1
and
321/2
,
they have to be pushed off the drive shaft
213.
♦
The mating surfaces of the shaft sealing rings are
made of chromium oxide coated steel rings, which
can be replaced at the factory if necessary.
7.6.3 Dismantling drive unit oil bath lubri-
cation
♦
Remove cylinder head screw
914/5
with toothed
lock washer
934/4
and pull the drive magnet assem-
bly
858
from the drive shaft
213
. For this purpose,
do not use any magnetisable tools if at all possible.
Caution ! Magnetic forces!
Risk of accident !
♦
Remove hex. screw
901/4
and drain oil.
♦
Remove hex. socket screws
914/6
and pull off the
rear bearing cover
361
with shaft seal
421/1
and o-
ring
412/1
.
♦
Remove wavy spring washer
953/1
.
♦
Pull or push the drive shaft
213
with the rolling bear-
ings
321/1
and
321/2
out of the bearing pedestal
330
in the direction of the motor.
♦
To change the rolling bearings
321/1
and
321/2
,
they have to be pushed off the drive shaft
213
.
♦
If necessary, press the shaft seals
421/1
and
421/2
out of the bearing pedestal
330
and rear bearing
cover
361
.
♦
The mating surfaces of the shaft sealing rings are
made of chromium oxide coated steel rings, which
can be replaced at the factory if necessary.
♦
It is recommended to also change the shaft seals
421
when the bearings are being replaced.
