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ATTENTION
It is important to clean the grease nipples prior
to lubrication so as to prevent foreign materials
from being dragged into the bearing.
The lubrication intervals informed on the plate consider
a working temperature of the bearing of 70 °C.
Based on the operating temperature ranges listed below,
apply the following correction factors for the lubrication of
bearings:
Operating temperature below 60 °C: 1.59.
Operating temperature 70 °C to 80 ºC: 0.63.
Operating temperature 80 °C to 90 ºC: 0.40.
Operating temperature 90 °C to 100 ºC: 0.25
Operating temperature 100 °C to 110 ºC: 0.16.
6.5.1.3
Relubrication of bearing with the
alternator operating
Bearing with grease outlet by runoff drain
1. Remove the cover of the drain;
2. Clean with a cotton cloth around the hole of the grease
nipple;
3. With the alternator running, inject grease until new
grease begins to flow from the drain or until the amount
of grease informed on the bearing nameplate have been
injected;
4. Run the alternator for time enough to eliminate the
excess of grease through the drain;
5. Inspect the bearing temperature to make sure that there
was no significant change;
6. Put the cover of the drain back in place.
Bearings with grease outlet by a drawer and rod
1. Before starting the lubrication of the bearing, clean the
grease nipple with a cotton cloth;
2. Remove the drawer and rod to remove the old grease,
clean the drawer and put it back;
3. With the alternator running, inject the amount of grease
specified on the nameplate of the bearings using a manual
grease gun;
4. The excess of grease comes out through the bearing
lower drain and is deposited in the drawer;
5. Maintain the alternator running long enough for the
grease excess to drain;
6. This grease must be removed by pulling the rod and
cleaning the drawer. This procedure must be repeated
as many times as necessary until the drawer no longer
retains grease;
Inspect the bearing temperature to ensure that there was
no significant change..
6.5.2
Bearing
ATTENTION
For safety reasons, the change of bearings
must be done with the alternator
disconnected from the driving machine.
To change the bearings on the alternator, it is necessary
to disassemble the alternator completely.
6.5.2.1
Bearing replacement
The disassembly of the bearings must always be done
with the use of appropriate tools (bearing puller).
Figure 6.1: Bearing extractor
ATTENTION
A bearing must only be removed from the
shaft when absolutely necessary.
Instructions:
1. The puller jaws must be placed on the side surface of
the bearing internal ring or on an adjacent part.
2. Before the installation of the new bearings, the shaft
seats must be cleaned and slightly lubricated.
3. The bearings must be heated up to a temperature
between 50 °C and 100 °C to facilitate the assembly.
6.6 MAINTENANCE OF THE EXCITER
6.6.1
Exciter
For the proper performance of its components, the
alternator exciter must be kept clean.
Check the insulation resistance of the windings of the
main exciter and auxiliary exciter periodically so as to
determine the insulation conditions, following the
procedures described herein.
6.6.2
Diode test
Diodes are components that last for a long time and do
not require frequent tests. If the alternator presents a
defect, which indicates a diode fault or an increase in the
field current for the same load condition, then the diodes
must be tested in accordance with the following
procedure:
1. Disconnect all the diodes from the exciter rotor
winding;
2. With an ohmmeter, measure the resistance of each
diode in both directions.
Installation, operation and maintenance manual
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