Shaft Alignment

When it comes to the topic of alignment,
let’s accept the fact that “coupling alignment”
is a misnomer. We are not concerned
about bringing coupling halves into alignment—
we’re only interested in ensuring that the
shafts of the pump and its driver will rotate on a
common axis. If the shafts are not coaxial, the
resulting moments will increase the forces on the
pump shaft and bearings, causing accelerated wear
and premature failure.

In most installations, it’s accepted that perfect
shaft alignment is unlikely throughout the operating
cycle. In such conditions, the coupling selection
should be able to accommodate the maximum
amount of the misalignment anticipated. This
should be confirmed with the coupling supplier, as
even flexible couplings have limitations that are
often ignored, resulting in premature bearing failure
and unreliable operation.