Balancing of a Flexible Rotor : 5th Report, Vibration and Balancing of a Flexible Rotor on Flexible Bearing with Viscous Damping

Abstract

Unbalanced vibration of a flexible rotor supported on two bearings is analysed in this paper for the case of flexible support with viscous damping. The analytical solution is obtained by using the concept of "forced mode", which makes the vibration phenomena for the system in consideration more understandable than before. Based on this solution, the condition as well as a possible procedure to balance such a rotor is theoretically demonstrated, conclusions of which are: (i) It is possible to obtain the universal state (in a practical sense) of balance of a flexible rotor which is satisfactory irrespective of its bearing properties, the magnitude of elasticity and viscous damping, through dynamic balancing and modal balancing of the rotor for the simply supported end condition, and (ii) this can be successfully be achieved by measuring shaft vibration of the rotor on flexible bearing with viscous damping.