转子-滑动轴承系统支承松动-碰摩故障动力学行为及评估方法

本文针对转子-滑动轴承系统支承松动-碰摩故障动力学行为进行分析,并提出基于动力学行为非线性度量的转子-轴承系统支承松动状态评估方法.应用非线性短轴承油膜力模型、松动刚度模型、Hertz接触理论等建立了带有支座松动故障的转子系统局部碰摩动力学模型,研究并分析松动-碰摩故障转子系统随支承松动间隙变化的动力学行为规律.提出基于动力学行为非线性度量的转子-滑动轴承松动-碰摩故障下支承松动状态评估方法,采取泰勒展开获得线性近似动力学模型,量化比较非线性模型与线性近似模型动力学行为的差异.建立松动间隙与非线性度之间的对应关系,直观反映松动间隙对系统动力学行为的影响程度,实现对转子-滑动轴承系统支承松动状态的评估.本文的研究可为转子-滑动轴承系统支承松动状态评估提供理论基础和支撑.

DYNAMIC BEHAVIORS AND ASSESSMENT OF LOOSE-RUBBING FAULTS IN ROTOR-SLIDING BEARING SYSTEM

In this paper, dynamic behaviors of rotor-slip-bearing system with loosening-rubbing faults are analyzed , and the evaluation method for the support loosening of rotor-bearing systems is proposed. The dynamic model of the local rub-impact for the rotor system with support looseness is established by using nonlinear short-bearing oil film force model, the loose stiffness model and the Hertz contact theory. The dynamic behaviors of the system with looseness and clearance is studied and analyzed. Then, a method of evaluating the bearing looseness for the rotor-sliding bearing under loosening-rubbing faults is proposed based on the nonlinear measurement of dynamic behaviors. The linear approximation kinetic model is obtained by Taylor expansion, and the differences between nonlinear model and its linear approximation model are quantified. Meanwhile, the relationship between looseness gap and nonlinearity degree is established, the influence degree of looseness gap on the system is intuitively reflected, and the looseness state of rotor-sliding bearing system is also evaluated. The results of this paper can give the theory and foundation for the assessment of support loosening in rotor-sliding bearing systems.