Fault Analysis to Cracked Over-Hung Rotor-Bearing System with Seal
Chen Hong(1,2),Zhang Xiaowei(3),Song Xueping(1),Wen Bangchun(1)
(1 Northeastern University Shenyang 110004, China) (2 Shenyang Blower (Group) Wo rks LTD. Shenyang 110022, China)
(3 Guangdong University of Technology, Guangzhou, 510090, China)

Abstract: The differential equations of motion are established aimed at dual-disk vertical over-hung rotor-bearing system, and the dynamic characteristics of cracked rotor are analyzed numerically under nonlinear seal fluid dynamic force and oil-firm force. It indicates that complicated nonlinear phenomena at different angular frequencies appear as the shaft crack gets a certain depth, such as period-kmotion, quasi-periodic motion and chaos motion. The rotor system operating away from the critical angular velocity is very sensitive to crack fau lt, and the rotor system operating near critical angular velocity is unsensible, but the crack affects the motion state severely, which provides theoretical ref erences for safe operation and fault diagnosis of the rotor-bearing systems.
Keywords: over-hung rotor, seal. nonlinear oil-firm force, crack.