ACTIVE VIBRATION CONTROL OF JOURNAL BEARINGS WITH THE USE OF PIEZOACTUATURS

The paper presents the results of the first test with the active vibration control of journal bearings. The test stand consists of a rigid rotor, which is supported by two journal bearings. The rotor is driven by an inductive motor. The journal bearing pedestal contains a movable bushing. The bushing position is controlled by two piezoactuators. The journal vibration inside the bearing bushing is measured by a pair of proximity probes, which are arranged mutually perpendicularly. A system, based on a PCL, is controlling RPM of the rotor and is enabling run-up, coast-down and steady-state rotation at the controlled way. A real-time simulator dSpace as a controller is determining the voltage for the piezoactuators according to error signals produced by the proximity probes. The mentioned voltage is connected to the input of an amplifier, which is controlling force and displacement of two pairs of piezoactuators. The active vibration control is aimed to eliminate instabilities due an oil film and to extend the operational range of a rotor rotational speed.