19
2.6 Shaft/Coupling alignment
CAUTION
Shaft alignment must be correct for successful operation. Rapid wear, noise, vibration and
actual damage to the equipment may be caused by shaft misalignment. The shafts must be
aligned within the limits given within this section.
NOTE
Adjustment to correct the alignment in one direction may alter the alignment in another direction.
Always check in all directions after making any adjustment.
Coupled equipment must be aligned to minimize unnecessary stresses in shafts, bearings and
coupling. Flexible couplings will not compensate for appreciable misalignment. Foundation settling,
thermal expansion or nozzle loads resulting in baseplate/foundation deflection and vibration during
operation may require the full coupling misalignment capability.
2.7 Types of misalignment
There are two types of shaft misalignment: angular and offset. Therefore, two sets of
measurements and corrections are required. Both types of misalignment can occur in horizontal
and vertical planes and are present in most applications.
A.
Angular misalignment
In angular misalignment, the centre line of the shafts intersect, but are not on the same axis.
ANGULAR MISALIGNMENT
