Automatic Modal Balancing of Flexible Rotors During Operation: Computer Controlled Balancing Head

Abstract

Modal balancing experiments are performed with a JIexibEe rotor-bearing system by using a single wireless, computer controlled precision balancing head. The balancing head is activated by the command signals generated from a personal computer, so that the estimated modal unbalance is cancelled and rotor vibrations are kept relatively small as the rotor system passes through critical speeds. During operation of the rotor-bearing system, the vibrations measured by proximity probes are sampled inio the computer and analysed to determine the modal unbalance of the rotor. The active control procedures which counterbalance the modal unbalance using the balancing head are described in this paper along with the theoretical background of the control system for the isotropic rotor-bearing system. Laboratory experiments show that the balancing head and computer control system designed is effective in modal balancing and reliable well over thejrst and second critical speeds.

Adaptive control of active balancing system for a fast speed-varying Jeffcott rotor with actuator time delay

“…To avoid this uneconomical modeling procedure and to cope with changing dynamics, an adaptive control scheme is preferred. There are several adaptive control methods for constant-speed balancing [3,4] and active balancing of speed-varying rotors [5−8] , they did not involve in time delay existing actually in active balancing systems.…”

Development of the active balancing device for high-speed spindle system using influence coefficients

“…Since the off-line balancing is done with the system stopped, it causes a great amount of loss in terms of time and cost. In order to reduce the loss and improve operation efficiency and accuracy, there are many ongoing research and development about on-line active balancing which is done with the rotating system run by moving the balancing rotor [1][2][3][4][5].…”

The stability of active balancing control using influence coefficients for a variable rotor system

“…Off-line balancing causes a lot of loss of time and cost, and it cannot deal with the case of changing the unbalanced distribution during rotating. There have therefore been many researches about on-line active balancing, which balances automatically with a moving balancing rotor during the working of a rotating machine [1,2,3,4,5].…”