Abstract
Recently, in order to increase the performances of rotating machinery, the radial clearance between the rotating shaft and casing became smaller and smaller. As a result, if the rotor contact with casing, severe self excited vibration frequently occurred in the rotating machinery systems, so called "Dry-Whip". Especially, self excited vibration with change of rotating speed (Contact type backward whirling) is able to occur under very small clearance condition such as practical rotating machinery. This work presents a theoretical and experimental study of such self excited vibration due to the rubbing which occurs on rotor and casing system with finite driving torque. As a result, it is shown that the rotor shows two deferent vibration behavior due to the natural frequency of casing. Those behavior shows deferent vibration phase of rotor and casing, zero or 180 degrees. And, it is shown that effect of physical condition of system for this phenomenon.
