Frequently Asked Questions on Dynamic Balancing Machines and Answers(A)
Q. In Dynamic Balancing do we need to support the component on the
machine in the same location as in assembly?
A. Yes it is necessary to support the component being balanced at the
same or near about of the bearing supports for proper results.
Dynamic balancing is a force balancing and couple balancing
Operation. The couple is the product of force and the distance to
the point of support. So it is essential that the real life conditions are
replicated on the balancing machines.
Q. In Dynamic Balancing Machine do we need to run the component
being balanced to operating speed/service speed?
A. Using a dynamic balancing machine we measure the unbalance in
the units of gram millimeter. The quality and sensitivity of balancing
Machine decides the speed at which you can balance a
Component. In modern hard Bearing dynamic balancing Machines
Engineers are able to measure the un balance at relatively lower
Speeds. The unbalance corrections effected are valid for most of
The service speed requirements of rigid rotors. Refer to the ISO
1940 standards to determine the residual un balance permitted in
Q. What are rigid rotors?
A. The rotors which do not change shape when speed of rotation
Increases, or the ones which do not operate at resonant frequency,
are classified as rigid rotors.
Q. What are flexible rotors?
A.Flexible rotors are rotors which operate near their resonant
frequency. This running of motor generates very slight deformation
of the rotor. Flexible rotors need to be balanced at higher speeds
and also near their service speeds. Many times, in situ balancing is
required to achieve desired results.
Q. What are soft bearing dynamic balancing machines and hard
bearing dynamic balancing machines?
A. Few decades back, when balancing machines were introduced, the
cradle on which the rollers were supported needed to be moved to
measure the vibration levels due to unbalance. With the advent of
technology and introduction of quartz transducers to measure force,
it is no longer required for the cradles to oscillate to measure
The machines which continued to have oscillating cradles and
electro dynamic picups to measure vibration were classified as soft
The machines which had rigid cradles devoid of any movement and
measure force using piezo or other picups are classified as hard
bearing dynamic balancing machines.
The basic design philosophy of hard bearing dynamic balancing
machines is measuring force and the advancement of
computational mathematics using microprocessors has enabled
introduction of balancing machines whose calibrations are valid for
the complete range of speeds, weights and quality requirements.
The algorithm used facilitates permanent calibration and host of
other features for day to day use and extreme reliability.