Bearing on exhaust cylinder mode is often used for large turbine unit. The paper sets up an equivalent analysis model to consider the influence of support pedestal stiffness. The support system is modeled as vibration mass and support stiffness and bearing oil film as eight stiffness and damping coefficients. There is large influence of support pedestal stiffness on vibration of bearing on turbine exhaust cylinder. Both of support system equivalent stiffness and damping coefficients are influenced largely. Relationship among the absolute shaft vibration, the relative shaft vibration and bearing vibration is different at different support stiffness cases. If support stiffness is low, phase difference between shaft vibration and bearing vibration may be large. Support stiffness characteristic can be evaluated from three kinds of vibration signals. Absolute shaft vibration monitoring is more important for bearing on exhaust cylinder than that of the relative shaft vibration. Vibration of bearing on cylinder is sensitive to rotor unbalance. Accurate balance is effective to reduce vibration of this kind of system.
GAO Qingshui LIU Shi ZHANG Chu.
Research on the Influence Factors for Vibration of Bearings on Turbine Exhaust Cylinder[J]. Journal of Vibration and Shock, 2014, 33(13): 26-30
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