Balancing or a Flexible Rotor : The Sixth Report, Some Experiments of Balancing Irrespective of Characteristics of Supporting Structure

Abstract

Unbalanced vibration and balancing of a flexible rotor/bearing system have been studied analytically in the preceding paper by the same authors for the case of elastic support with viscous damping. Based on the theoretical results obtained, some experiments are carried out and the analysis is verified experimentally with the following conclusions: (1) The vibration of the system due to unbalances is no longer a linear combination of undamped eigen-modes of an elastically supported rotor but that of forced modes of a damped system. (2) The bearing- and shaft-vibrations are minimized within the whole speed range up to the operating speed, if the rotor is balanced by means of dynamic- and modal-balancing for a simply supported rotor. (3) The rotor can be successfully balanced if bearing- and shaft-vibration is measured at high speed, even though the dynamic characteristics of the supports are not known.