油膜支撑双盘转子-轴承系统周期运动稳定性与分岔
Stability and bifurcation of the rotor-bearing system with double disks supported by cylindrical bearings
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摘要:建立了考虑油膜支撑的双盘转子-轴承系统多自由度模型, 将与Newmark结合的延拓打靶法应用到多自由度系统的周期稳定性分析中. 主要研究双盘转子-轴承系统在转盘偏心量、偏心初始相位、轴承间隙、润滑油动力黏度以及轴承长径比5个参数域内的变化规律,得到一些有益结论: 该系统的周期运动主要以倍周期或拟周期分岔而失稳; 采用较小的转盘偏心量或增大转盘的初始偏心相位差可以提高失稳转速; 为抑制系统过早失稳, 应适当提高轴承长径比和尽可能采用较小的轴承间隙; 在选用润滑油时, 并非其动力黏度越大越好, 动力黏度较小的润滑油反而可以适当提高系统失稳转速. 研究方法和结果为相关及更为复杂的转子-轴承系统的稳定性设计及振动控制提供了理论参考.Abstract:Continuous model of rotor-bearing system with double diskssupported by cylindrical bearings is analyzed in this paper. Shooting methodis used in the stability analysis of the continuous system. Therotor-bearing system with double disks is analyzed by considering the diskeccentric magnitude, eccentric initial phase, bearing clearance, dynamicviscosity of the oil and bearing aspect ratio. Some useful conclusions arefound: instability is mainly caused by the period-doubling or quasi-periodbifurcation; instability speed can be increased by decreasing the diskeccentric magnitude or increasing the initial eccentric phase difference ofthe disk; increasing bearing aspect ratio and decreasing bearing clearanceproperly can inhibit the instability occurring early; the higher dynamicviscosity of the oil is not the better, otherwise oil with lower dynamicviscosity can increase the instability speed properly. Research method andconclusions in this paper can provide theoretical reference for thestability design and vibration control of the more complex rotor-bearingsystem.