Q. What are the criteria for selection of end driven, belt driven, self
driven, vertical balancing machines?
A. In a dynamic balancing requirement, the accuracy of the
component and the ease of balancing decide the most techno
economical solution in selecting the balancing machine and drives.
Mass produced components which are disk in shape, and small in
size are invariably balanced on a vertical machine with built in
correction equipments. High precision jobs requiring fine levels of
balance like turbines, turbochargers, are balanced on belt driven
machine. Components like fans and heavy rotors which need
considerable power for acceleration and deceleration are driven
through universal shafts on a balancing machine. Very high speed
components like automobile turbochargers wherein the error
induced by drive elements are not acceptable are balanced by
using their own real life simulated power sources like compressed
air. The advantage of the belt drive arrangement over universal
shaft driven machine is the time to fix the adopters on the
component is saved and errors due to adopters on the residual
unbalance are avoided.
Q. What are the units of unbalance?
A. The units of unbalance are the product ( Multiplication ) of
permitted un balance weight at the radius of correction.
For example
X gram of unbalance at Y millimeter radius is defined as XY mmg of
unbalance. Based on the practice the units can be in
Meter gram
Ounce inches
Gram inches
Millimeter gram
Millimeter milligram
Or the product of a linear distance unit and a weight unit. the
relationship between all the units is straightforward and can be
transferred for operational convenience
Q. What are the criteria for selection of end driven, belt driven, self
driven, vertical balancing machines?
A. In a dynamic balancing requirement, the accuracy of the
component and the ease of balancing decide the most techno
economical solution in selecting the balancing machine and drives.
Mass produced components which are disk in shape, and small in
size are invariably balanced on a vertical machine with built in
correction equipments. High precision jobs requiring fine levels of
balance like turbines, turbochargers, are balanced on belt driven
machine. Components like fans and heavy rotors which need
considerable power for acceleration and deceleration are driven
through universal shafts on a balancing machine. Very high speed
components like automobile turbochargers wherein the error
induced by drive elements are not acceptable are balanced by
using their own real life simulated power sources like compressed
air. The advantage of the belt drive arrangement over universal
shaft driven machine is the time to fix the adopters on the
component is saved and errors due to adopters on the residual
unbalance are avoided.
Q. We have balanced a fan on the balancing machine and when we
test on a static balancing stand we see heavy spot in the fan?
A. In the picture above a dynamic balancing machine measures the
resultant of the three resultant unbalance forces namely the static
component “S “, and the couple component “+C and -C” The
values can be recorded by using the program two plane measuring
and static/couple measuring sections.
When using a machine you compensate all un balances ie S,+C,-C.
But when check on a static balancing stand the couple portion un
balance do not get compensated , and only S is compensated . So
you have the high spot settling at the bottom on a static balancing
stand for components balanced on a machine. In actual service
conditions when the dynamic effect of all three forces are acting the
fans balanced on a machine for both Static and Couple will be
smoother.
