CEMB N330, Руководство пользователя

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Balancing accuracy of rigid rotors G - 7
The permissible residual unbalance for one correction plane is usually given by the product of
the overall permissible residual unbalance of the entire rotor and the relationship between the
distance of the other correction p
lane from the rotor’s barycenter and the distance between
the correction planes.
Note:
If the rotor does not come under any of the simplified methods listed, you must follow
the general method, which is valid for any rotor and any position of the correction
planes.
Practical use diagrams for correcting unbalance
Drilling in steel:
Use diagrams 1 to 5 according to need. Each diagram supplies the depth of the drill hole (h), as
a function of the weight to be removed (P) and the diameter of the drill bit (d). The curves are
plotted for steel (density 7.85 kg/dm3), taking the conical shape (120°) of the drill bit into
account, using the following criterion:
Unit of measurement:
The total weight to be removed from a drill
hole is:
P = 7.85 10
-3
V (where V is the total volume
of the hole) (1) considering that:
Drilling in alumin um, cast iron etc…
Once you know the weight that has to be removed, you must multiply it by a correction
coefficient designed to take the different densities of the materials into account. The resulting
weight is used in diagrams 1 to 5 to determine the correct value of hole depth (h).
EXAMPLE:
Unbalance to remove P = 10 grams
Drill bit used d = 14 mm
Rotor material ALUMINUM
Corrected P value = 10x2.91 = 29.1
Diagram 1 gives us h = 27 mm