Research On The Stability Of Vertical Rotor Bearing System

The stability of vertical rotor-bearing system is very poor,for its light-loaded feature. The vertical rotor has been widely applied in the area of war ship, hydraulic turbine and oil field, however, the theoretical and experimental research on the vibration characteristics of vertical rotor-bearing system is not yet clear, and there is considerable theoretical and experimental difference. Therefore, we need some further study on the mechanism of vertical rotating machinery.A finite element model under the non-linear film force is established for the vertical, horizontal and tilting arranged rotor bearing system, and then, Newmark method is used to integrate the differential equation of the systems. Bently-RK4 test rig is used as prototype of the finite element analysis and experimental study; Euler beam element is used to model the rotor part and Capone nonlinear oil film force model is used to simulate the plain journal bearing, the disk is assumed to be intensive mass element.The oil whirl and oil whip feature of rotor bearing system under different tilting angle is obtained in frequency domain and time domain; the stability of horizontal, vertical and tilting rotor-bearing system is compared; the influence of the aspect ratio, radius clearance, lubricant dynamic viscosity, and the mass eccentric of rotor-disc on the rotor bearing system stability is analyzed.Finally, some experimental studies are done on the stability of tilting rotor-bearing system, the stability law is obtained; and in accordance with numerical simulations and the related experimental results, the method to raise the stability velocity of the rotor in different tilting angle is summarized.