CEMB N330, Руководство пользователя

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Rotors balancing mode 11 - 19
Warnings on Permissible Unbalance accordingly to
ISO 21940-11
N330 device helps the user performing a comparison between the residual unbalance and the
permissible unbalance as described by
ISO 21940-11 .
In the case of rotors that need two correction planes, N330 device calculates the permissible
unbalance under some hypothesis:

The rotor is an “inbound rotor” (i.e. the bearing planes A and B are external to the
correction planes I and II in the following figure)

The rotor is almost symmetric (i.e. the distance of its center of mass CM from the
bearing planes A and B is almost the same)

The correction planes I and II are near to bearing planes A and B , and so the
permissible unbalances can be allocated to the correction planes
This scenario is the most common one and so N330 device covers most of the cases.
In all the other situations the user should calculate the permissible unbalances by himself, as
described in the
ISO 21940-11 (see Appendix G – Balancing accuracy of rigid rotors ).