Takayoshi Fujii

Vibration control for an overhung roller in textile machine considering the stiffness of control device stand

Abstract This paper treats a vibration control method that can be used in textile machinery to reduce the unbalanced vibration of an overhung roller–motor system. To control the vibration of the overhung roller, a drive motor with a hybrid type vibration control device consisted with rubber springs and electromagnets is used. When the vibration control system is set up in the textile machinery for industrial use, the stand supporting the control system to the base may be assumed not too rigid but elastic. For a certain value of the elastic stand stiffness, the vibration control performance of the overhung roller becomes very low. In order to prevent this deterioration, a stiffness control achieved by a positive feedback of the displacement signal of the rubber spring is proposed and the effectiveness of the stiffness control is confirmed by simulations and experiments.

Active Vibration Control of an Overhung Rotor System Considering Stand Stiffness.

This paper describes a method to effectively reduce the unbalanced vibration of an overhung rotor system. We propose a hybrid type damping device in which a bearing pedestal is supported elastically by rubber springs and controlled actively by electromagnetic actuators. The damping device is mounted in a motor casing which is set on an elastic stand. When the damping device is supported elastically, the suppression effect often deteriorates. In order to prevent this deterioration, we apply a stiffness control which is achieved by conducting positive feedback of the displacement signal. In the analysis, we calculate the controller gains that minimized the compliance of the overhung portion in consideration of the stand stiffness. In the experiment, the results correspond to the analytical results, and we confirm that the application of the stiffness controller is a highly effective method for vibration suppression.