Trial mass for balancing rotors

[heitor]

Hello!

Do you know any "rule of the tumb" to choose the trial mass for balancing rotors?

Thank you!

 

[desertfox]

Hi heitor

I have no rule of thumb for what mass you should choose to
start with, but I do have a reference to a method here how you can find out where to place your mass.

1/ rotate the rotor on knife edges

2/ the heavier section will stop at the bottom ie the lowest
point.

3/mark the heavy point with chalk and place a small balance
mass diametrically opposite.

4/ rotate the rotor through 90 degrees and again allow to
rotate freely, again the heavier section will rotate to
the bottom.

5/ The balance mass is now increased or decreased
accordingly and the process repeated untill the rotor
remains at rest in any position.

Hope this helps

regards desertfox

 

[sms]

The kind of standard rule of thumb for field balancing is that you start with a weight that will cause a centrifugal force equal to 10 to 20% of the weight of the rotor. For light high speed rotors (like a compressor) I go 10% for heavy lower speed rotors (like a generator) I go 20%.

 

[heitor]

Thank you all