Practical Solutions to Machinery and Maintenance Vibration Problems
Chapter 5, Unbalance
Section 3, Various Combinations of Dynamic Unbalance
Confusion often results when "static unbalance" is also referred
to as "dynamic unbalance." the confusion is very understandable
as dictionary definitions suggest that the word "static" has
an opposite meaning to the word "dynamic." True! But unfortunately,
the phrase "static unbalance" was derived from an old method
used for static balancing (on a static balancing machine, usually a
set of rollers on a stand). The static unbalance was revealed as the
rotor was rolled by gravity to the 6:00 o'clock position. For understanding
unbalance itself and especially for vibration analysis, it's best not
to visualize the method used for removing static unbalance, but to instead
visualize the in-phase and equal forces.
This textbook contains only part of the information in our Practical Solutions seminar.