Coupling - WEG GPW Series Installation, Operation And Maintenance Manual

Thus we get an indication of how much it is necessary to
raise or lower the alternator or move it to the right or left
on the drive end in order to eliminate the coaxial error.
Half the difference of the dial gauge measurement in a full
revolution represents the maximum eccentricity.
The maximum acceptable eccentricity for rigid or
semi-flexible coupling is 0.03 mm.
Where flexible couplings are used, higher values than
those aforementioned are acceptable, but they must not
exceed the value given by the coupling manufacturer. It is
recommended to keep a safety margin in these values.
Angular misalignment
Figure 4.9: Angular alignment
Figure 4.9 shows the angular misalignment and the
practical way of measuring it
The measurement is made in four points at 90º, with the
two half-couplings rotating together so as to eliminate the
effects of surface irregularities on the dial gauge contact
surface. Choosing the upper vertical point 0º, half the
difference of the dial gauge measurement in points 0º
and 180º represents the vertical misalignment. This must
be properly corrected by adding or removing shims.
Half the difference of the dial gauge measurement in
points 90° and 270° represents the horizontal
misalignment. This must be properly corrected with the
lateral/angular movements of the alternator.
Half the maximum difference of the dial gauge
measurement in a full revolution represents the maximum
angular misalignment.
The maximum acceptable misalignment for rigid or
semi-flexible coupling is 0.03 mm.
Where flexible couplings are used, higher values than
those aforementioned are acceptable, but they must not
exceed the value given by the coupling manufacturer.
It is recommended to keep a safety margin for these
values.
In alignment/leveling, it is important to consider the effect
of temperature of the alternator and of the driving
machine. Different levels of expansion of the coupled
machines can change the alignment/leveling during the
operation.
Axial measurement

4.10.3 Coupling

It must be used coupling that optimize the vibration level
of the set.
ATTENTION
Carefully align the shaft ends, using a flexible
coupling whenever possible, leaving a
minimum clearance of 3 mm between the
couplings.
Figure 4.10 - Axial clearance
NOTE
The user is responsible for the installation of the
alternator.
WEG is not responsible for damages to the
alternator, associated equipment and
installation which occurred due to:

Excessive transmitted vibrations;

Poor installations;

Alignment failures;

Improper storage conditions;

Noncompliance with the instructions before
start-up;

Incorrect electrical connections.
Installation, operation and maintenance manual
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Axial clearance
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