Effect of Angular Oil Film Coefficients on Stability Characteristics of Rotor-Bearing System

研究了角油膜系数对轴向轴承支承弹性转子稳定性特性的影响。角油膜系数数值获得圆形轴承，2叶至4叶轴承，倾斜垫轴颈轴承。构造了考虑角油膜系数的Jeffcott转子，计算了大工况下的稳定阈值转速。当转轴刚度较高时，角油膜系数不影响转子-轴承系统的稳定性，而当转轴非常灵活时，稳定阈值速度增加，表明角油膜系数提高了转子-轴承系统的稳定性。具有高预紧系数的双瓣轴承在稳定性图中覆盖的稳定区域比其他轴承大得多。从结果来看，具有高预紧系数的2瓣轴承最适合支撑柔性转子。

The effects of angular oil film coefficients on the stability characteristics of an elastic rotor supported in journal bearings are investigated. Angular oil film coefficients are numerically obtained for circular bearings, 2-lobe to 4-lobe bearings, and tilting pad journal bearings. A Jeffcott rotor considering the angular oil film coefficients are constructed, and stability threshold speeds were calculated under wide operating conditions. While the angular oil film coefficients do not affect the stability of the rotor-bearing system when the stiffness of the rotating shaft is high, the stability threshold speed increases when the shaft is very flexible, indicating the angular oil film coefficients improve the stability of the rotor-bearing system. Two-lobe bearings with a high preload factor cover much larger stable region in the stability charts than the other bearings. From the results, 2-lobe bearings with a high preload factor are most suitable for supporting the flexible rotor.