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

点击翻译按钮获取中文摘要

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.