2021.06 / o
17
Electric Power Generation
Installation and maintenance
LSA 42.3
Low Voltage Alternator - 4 pole
4803 en -
• Replacing the NDE bearing on single
bearing machines
Dismantling
- Remove the NDE shield (36).
- Remove the ball bearing (70) using a screw
puller.
Reassembly
- Heat the inner slipring of a new bearing by
induction or in a drying oven at 80 °C (do not
use an oil bath) and fit it to the alternator.
- Place the preloading wavy washer (79) in
the shield.
- Replace the NDE shield (36).
• Replacing the bearings on two-bearing
machine
Dismantling
- Uncouple the alternator from the prime
mover.
- Remove the assembly screws.
- Remove the DE shield (30).
- Remove the NDE shield.
- Remove both antifriction bearings (60) and
(70) using a puller with a central screw.
Reassembly
- Heat the new bearings by induction or in a
drying oven at 80°C (do not use an oil-bath)
and fit them to the machine.
- Check that both the preloading wavy
washer (79)
have been fitted on the NDE
shield (36).
- Refit the DE shield (30) and tighten the
fixing screws.
- Check that the alternator assembly is
correctly mounted and that all screws are
tightened.
• Accessing the main field and stator
Dismantling
Follow the procedure for dismantling
bearings.
- Remove the coupling discs (single-bearing
alternator) or the DE shield (two-bearing
alternator) and insert a tube of the
corresponding diameter on the shaft end or
a support made according the following
bellow.
- Rest the rotor on one of its poles, then slide
it out. Use the tube as a lever arm to assist
dismantling.
- After extracting the rotor, be careful not to
damage the fan and place the revolving field
on special V-blocks.
NOTE: If intervention is required on the
main field (rewinding, replacement of
components), the rotor assembly must
be rebalanced.
Reassembling the revolving field coil
- Follow the dismantling procedure in
reverse order.
Take care not to knock the windings when
refitting the rotor in the stator.
If you replace the fan, respect the assembly
guide according the following bellow. Use a
tube and a screw.
