Abstract
The ball balancer has been used for the vibration suppression method in rotor system. It has a sperior characteristic that the vibration amplitude is reduced to zero by it at the rotational speed range higher than the major critical speed. However, the ball balancer may cause a self-excited vibration when the balls rotate in the disk, and this self-excited vibration results in the large amplitude vibration. In this paper, the vibration suppression method for such vibration problems due to the ball balancer is investigated. Both the linear and nonlinear spring characteristic of the shaft are controlled by changing the axial position of the repulsive magnetic bearing (RMB). The influence of nonlinearity and the vibration suppression effect of the control parameters are investigated numerically and theoretically. The significant reduction of the occurrence region of theself-excited vibration is achieved by controlling the axial position of RMB appropriately.
