3.3.1.2 Shaft elevation caused by Thermal elevation
H(m) = Height of the machine axis
∆
T= frame temperature elevation = 30°C
λ
= Coefficient of steel elongation = 0.012 °K-1
3.3.1.3 Not applicable
3.3.1.4 Shaft elevation of Anti-friction bearing machine
Caused by thermal growth of the anti friction bearing.itself
1 -
cold
, in rotation, or stopped
2 -
hot
, in rotation, or stopped
3.3.1.5 Generator check before alignment
Check the generator shaft end run out.
Total Indicator Reading must be within 0.04 mm
NOTE:
RUN OUT CHECK CAN BE NOT FEASABLE ON
SLEEVE BEARING MACHINE BECAUSE OF THE TOO
HIGH NECESSARY BREAK AWAY TORQUE NEEDED
TO TURN THE ROTOR
3.3.1.6 Alignment procedure"Double concentricity"
alignment method
NOTE:
LASER DEVICES CAN MAKE THE JOB EASIER THAN
WITH THE SHOWN PROCEDURE
This method is not sensitive to axial movements.(the
alignment methods using axial measure may often be
perturbed by small axial movement of the rotor)
It is possible to check the alignment with the coupling
installed.
Equipment required :
Two rigid brackets. The rigidity of the two brackets is very
important.
Two micrometers
Implementation :
During the measures, both shafts must turn simultaneously
in the same direction. (For example : the coupling installed
with its screws untightened). By turning both shafts
simultaneously, the measurement is not affected by the
error resulting from run out of the two shaft ends.
C1
C2
A
B
3h
9h
12h
6h
L
The "C1" and "C2" micrometers are located at an angular
difference of 180°.
More the distance "L" is long better should be the
sensitivity to detect the angular error
The reading should be performed 4 times for the "C1" and
"C2" micrometers : at 12h, 3h, 6h, 9h
It is recommended to record the results and draw the axes
for better evaluation, as explained below. Interpretation of
measurements by means of an example.
Values given in millimeters. The reading is considered
positive (+) when the micrometer stylus is pushed inwards.
∆
H (mm) =
λ
(°K
-1
)
. H
(m)
.
∆
T
(°K)
"2"
Y ° 0,01 mm
"1"
Electric Power Generation
Installation and maintenance
5654
en - 2017.
10
/
a
LSA 5
2
.2
MHV
Industrial Range Alternators
- 4 pole
12
