42 l
Installation, operation and maintenance manual – Squirrel cage motor – W Line - Horizontal and vertical 11239449
7.10.1.6
Procedure for changing the grease
In order to replace the POLYREX EM103 grease by one
of the alternative greases, the bearings must be opened to
remove the old grease and then filled with the new grease.
If it is not possible to open the bearings, the old grease
must be purged by applying new grease until it begins to
appear in the exit drawer with the motor running.
In order to replace the STABURAGS N12MF grease by
one of the alternative greases, you must first open the
bearings, completely remove the old grease, and then fill it
with new grease.
ATTENTION
Since there is no grease compatible with
STABURAGS N12MF, other grease must
not be injected in the attempt to purge it. This
procedure will not expel completely the old
grease and they will mix, which may cause
damage to the bearings.
ATTENTION
When the bearing is opened, inject the new
grease through the grease nipple to expel
the old grease found in the grease inlet
tube, and apply the new grease in the
rolling bearing, to the inner and outer
bearing caps, filling 3/4 of the empty
spaces. In case of double bearings (ball
b roller bearing), also fill 3/4 of the
empty spaces between the intermediate
rings.
Never clean the rolling bearing with cotton-
based cloths, because they may release
some lint, working as solid particles.
NOTE
WEG is not liable for the grease change or for
any damages arising from this change.
7.10.1.7
Low temperature greases
Table 7.4: Grease for application at low temperatures
Manufacturer
Grease
Constant
operating
temperature
(°C)
Application
Exxon Mobil
MOBILITH SHC
100
(Lithium Soap and
Synthetic Oil)
(-50 to +150)
Low
temperature
7.10.1.8
Grease compatibility
You can say that greases are compatible when the
properties of the mixture are within the property ranges of
the greases individually.
In general, greases with the same type of soap are
compatible; however, depending on the proportion of the
mixture, there might be incompatibility. Therefore, it is not
recommended to mix different types of grease without
consulting the grease supplier or WEG.
Some thickeners and basic oils cannot be mixed, because
they do not form a homogeneous mixture. In this case,
one cannot rule the possibility of hardening or softening of
the grease, or reduction of the dropping point of the
resulting mixture.
ATTENTION
Greases with different types of base must
never be mixed.
For example: Lithium-based greases must
never be mixed with sodium or calcium-
based greases.
7.10.1.9
Disassembly – horizontal bearings
Figure 7.4: DE bearing
Figure 7.4 legend:
1.
Temperature sensor
2.
Grease nipple
3.
Grease collecting drawer
4.
Screw
5.
Protection disc
6.
Labyrinth taconite seal
7.
Screw
8.
Outer bearing cap
9.
Screw
10.
Grease flinger
11.
ND-end shield
12.
Rolling bearing
13.
Inner bearing cap
Before disassembling:
Remove the water from the cooling circuit, as described
in section 7.7 of this manual;
Place the motor in the horizontal position (vertical
machines);
Remove the extension tubes from the grease inlet and
outlet;
Thoroughly clean the external part of the bearing;
Remove the grounding brush (if any);
Remove the temperature sensors.
