MarelliMotori MXB-E 225 Serie Manuel D'installation page 43

6.4 Complete disassembly and reassembly operations (mechanical and
electrical parts)
BEFORE DISASSEMBLING THE GENERATOR FROM THE DRIVE MOTOR, MAKE SURE THE SAME
CANNOT BE STARTED.
Study the instructions before disassembling the generator. Moreover, check for the availability of
suitable lifting equipment for the weights of the components that have to be handled.
Check that all the handling safety measures have been adopted.
The disassembly and reassembly operations must be carried out by qualified and authorized personnel;
please refer to the workshops authorized by Marelli Motor Service.
Whenever needed, mark the components, when disassembling the machine, to identify their position
during reassembly.
Disconnect the generator from the drive motor; remove the fixing brackets on the feet, connections and coupling
device (SAE disk/joint). Disconnect the terminals of the power cables from the terminal box.

Distance the generator from the motor using the eyebolts on the generator.
For double bearing generators:
Follow the instructions of Chapter 6.3 until both shields have been disassembled.

Remove the rotor from the coupling side by being careful not to damage the windings.

Disassemble the various components by being careful not to remove the O-Ring from the N side shield.

Keep in mind that the exciter stator is secured on the N side shield.
For reassembly, after inserting the rotor in the casing, follow the reassembly instructions contained in Chapter
6.3 for the double bearing generators.
For single bearing generators:
Follow the instructions of Chapter 6.3 until the rotor is removed.

After removing the rotor, reposition the generator in a horizontal position; disconnect the white
conductors, (+) and (-), that go from the regulator to the exciter stator by removing the clamps.

Remove the screws that secure the N side shield to the terminal box.

Remove the tie-rods that secure the N side shield and the D side fitting to the casing.

Disassemble the various components by being careful not to remove the O-Ring from the N side shield.

Keep in mind that the exciter stator is secured on the N side shield.
Carefully install the bearings on the shaft, preferably by heating them at about 80-90°C.
The O-Ring must always be replaced at each disassembly.

Apply an even layer of LGAF 3E (SKF) grease on the entire surface of the ring outside of the bearing
and on the entire surface of its seat of the N side shield (without an O-Ring) using an appropriate tool
(brush or spatula). Excessive thickness could lead to complications during assembly of the bearing on
the shield.

Position the new O-Ring in its seat of the N side shield.

Before assembling the shield, make sure that the two guide screws are present on the lower part of the
casing.

Clean the threads of the tie rods before using them.

Assemble the N side shield and the D side fitting by securing the tie rods according to the instructions in
Chapter 6.5.

Connect the white conductors, (+) and (-), to the voltage regulator (see the connection diagrams) and
secure them with clamps.

After tightening the tie rods, position the generator in a vertical and stable position.

Insert the rotor vertically (with the bearing cooled) by being careful not to damage the O-Ring; if the N
side bearing does not fully fit in the seat, apply pressure on the head of the shaft until the rotor fully fits.

After slipping the rotor inside, lock the disc to the fitting using 2 appropriate clamps to prevent the rotor
from accidentally falling out when positioning the generator in a horizontal position.

Reassemble the protections on the N side shield.

Invert the sequences of the operations described for disassembly.

Since some fixing elements must be replaced, make sure to use spare parts of the same type and class
of resistance as the original ones. The valid tightening torques for the screws and fastening nuts are
reported here below:
963857253_= 40