DIN ISO 21940-11:2017-03

Rotor balancing is a procedure by which the mass distribution of a rotor is checked and, if necessary, adjusted to ensure the unbalance tolerance is met. This document covers the balancing of rotors with rigid behaviour. The balancing machines available today enable residual unbalances to be reduced to very low limits. Therefore, it is necessary to specify an unbalance quality requirement for a balancing task, as in most cases it would not be cost-effective to reduce the unbalance to the limits of the balancing machine. In addition to specifying an unbalance tolerance, it is necessary to consider the errors introduced by the balancing process. This standard takes into account the influence of these errors to distinguish clearly between the specified permissible residual unbalance and the reduced residual unbalance values to be achieved during the balancing process. This standard specifies a) the magnitude of the permissible residual unbalance; b) the necessary number of correction planes; c) the allocation of the permissible residual unbalance to the tolerance planes; and d) how to account for errors in the balancing process. German cooperation was provided by the committee NA 001-03-06-01 UA (NALS/VDI C 6) "Auswuchten und Auswuchtmaschinen" ("Balancing and balancing machines") at Standards Committee Acoustics, Noise Control and Vibration Engineering (NALS) at DIN and VDI.