摘要
转子系统因含间隙、约束、摩擦等典型的非光滑力学因素,使系统由于碰摩振动而表现出复杂的非线性动力学特性。以考虑碰摩故障的油膜轴承支撑的单盘柔性转子系统为研究对象,建立了系统的无量纲运动微分方程,采用变步长4阶Runge-Kutta法数值计算,研究模型的关键参数与系统动力学特性的关联关系。结果表明:随着约束刚度比取值的增大,系统的周期碰摩振动模式类型和分岔特征显示出多样性和复杂化,并且碰摩程度加剧。分析了在较大约束刚度比值条件下,系统在转速比取值范围内因设定的初始条件不同,而表现出两类周期碰摩振动共存现象。揭示了随间隙比取值的增大,系统的全周碰摩振动逐渐消失,以及周期振动的模式类型和分岔呈现先增多后显著减少的趋势;系统的最大碰摩力和碰摩占空比值持续降低,系统随之表现为无碰摩的1周期运动。研究结果对油膜轴承-转子系统在动态设计和故障诊断阶段避免碰摩振动具有实际指导意义。
With the typical non-smooth mechanical factors,such as clearance,constraint and friction taken into account,the rotor system has complex non-linear dynamic characteristics due to rub-impact vibration.This article focuses on the single-disk flexible Jeffcott rotor system supported by the oil-film bearings with the rub-impact fault,and the dimensionless differential equation of the system’s motion is set up.The fourth-order Runge-Kutta method is used for numerical calculation,in order to explore the relationship between the key parameters of the model and the dynamic characteristics of the system.The results show that with the increase of the constraint stiffness ratio,the periodic rub-impact vibration mode types and the bifurcation characteristics of the system show diversity and complexity,and the rub-impact degree is significantly severe.With the larger constraint stiffness ratio,the system has coexistence of the two types of periodic rub-impact vibration within the range of the rotation speed ratio due to different initial conditions.It is revealed that with the increase of the gap ratio,the whole-week rub-impact vibration of the system disappears gradually;the mode types and the bifurcations of periodic vibration increase and then decrease;the maximum rub-impact force and the rub-to-duty ratio of the system decrease continuously;the system subsequently displays the one-periodic rubfree motion.This study is of practical significance for the oil-film bearing-rotor system to avoid rub-impact vibration during the design and fault-diagnosis stages.
作者
尹凤伟
YIN Feng-wei(School of Mechatronic Engineering,Lanzhou Jiaotong University,Lanzhou 730070;Gansu Provincial Key Laboratory of System Dynamics and Reliability of Rail Transport Equipment,Lanzhou 730070)
出处
《机械设计》
CSCD
北大核心
2021年第10期94-101,共8页
Journal of Machine Design
基金
国家自然科学基金(11672121,11862011)
甘肃省科技计划项目(18YF1WA059)
吉林省高教科研课题(JGJX2020C118)。
关键词
油膜轴承-转子系统
碰摩振动
数值计算
分岔
转子动力学
oil-film bearing-rotor system
rub-impact vibration
numerical calculation
bifurcation
rotor dynamics
