Page 144 - Rotating Machinery Pratical Solutions to Unbalance and Misalignment

Rotating Machinery: Practical Solutions

very little time to make additional adjustments to obtain the exact
desired alignment. This small effort will now pay dividends in
extended equipment life.
Once the vertical alignment is completed, the horizontal
alignment can be tackled. The primary difference in the horizontal
alignment is that the rim indicator is set to zero at the 9 o’clock
position, since bar sag plays no roll in horizontal plane. Zero both
indicators at 9 o’clock and rotate the fixture and shafts to the 3
o’clock position to obtain the readings.
The layout of the graph and the calculator methods is per-
formed exactly as in the vertical alignment. The only difference is
that if the graph or the answer to the calculator method indicates a
plus (+) reading, the foot needs to be moved to the right. If the read-
ing or answer is negative, the foot needs to be moved to the left.

MOVING THE MACHINE
IN THE HORIZONTAL PLANE

Since this is a precision alignment method, banging the feet
with a lead mallet is not the most desirable method to move the
machine in the horizontal plane. However, there are several tech-
niques that will perform well on most machines. Although all of
these methods will not work on a given machine, one should be
adaptable to most situations. With a little thought, you may devise
other practical methods to precisely move the equipment.

1. If the machine is equipped with horizontal bolts, tighten all
jacking bolts snugly against the frame. Using the proper
thickness feeler gauge, loosen the jack bolt on the side the
machine needs to be moved toward, insert the feeler gauge
and run the jack bolt against it, then remove the feeler gauge.
Use the jack bolt on the opposite side to move the machine.

2. Mount dial indicators on the feet of the machine, to measure
the amount of movement at each foot location, on either side
of the machine. Move the machine while observing the align-