This work presents a analytical and experimental study of the contact type backward whirling between flexible rotor and flexible supported casing system due to the contact under the finite driving torque. As a result, it is shown that the rotor shows two different vibration behaviors due to some physical conditions of the system. These behaviors show the following difference. (1). vibration of different phase between rotor and casing (zero or 180 degrees). (2). amplitude of whirling, which is larger than clearance or not. (3). whirling frequency of rotor is higher than natural frequency of casing or not. And then, whirling pattern and frequency at steady-state, and effect of physical condition of the system are shown theoretically. The whirling pattern and frequency are greatly affected by natural frequency of casing, damping of rotor and casing and driving torque. And, low friction coefficient and large damping of system are particularly effective in prevention of this phenomenon.
展开▼
