隔振推力轴承振动能量泄漏的反演诊断

Vibration energy leakage analysis and diagnosis of vibration-isolation thrust bearing

[目的]隔振推力轴承是用于轴系纵向振动控制的新装置。试验中,发现轴系传递特性与理论预报值差距大,经判断是某隔振推力轴承出现了较严重的振动能量泄漏。为追溯系统声学性能不佳的成因及确定优化改进方向,聚焦推力轴承弹性部件开展研究。[方法]以裸弹簧和隔振缸为研究对象,反演隔振推力轴承振动传递。基于隔振理论与动力学试验,建立螺旋弹簧隔振缸动力学模型,设计垂向试验台架。[结果]研究结果表明:螺旋弹簧共振峰尖锐、光滑,而隔振缸的共振峰平坦且伴有接触摩擦产生的谐波成分;当存在接触摩擦时,产生了附加刚度和附加阻尼,显著影响了隔振缸的传递特性。[结论]研究验证了螺旋弹簧隔振缸的动力学模型。理想状态下所得的螺旋弹簧传递特性可作为隔振缸的优化改进标杆,结论可为轴系隔振的优化改进提供理论支撑,具有重要的工程价值。

[Objectives]The vibration-isolation thrust bearing is a new device for the longitudinal vibration control of propulsion shafts.Experimental results show that the dynamic transmission characteristics of the propulsion shaft are quite different from those of theoretical calculation predictions.Analysis shows that there is serious vibration energy leakage from the vibration-isolation thrust bearing.For better understanding the cause of poor acoustical property of the system,a study is conducted with the focus upon the flexible assem-blies of the thrust bearing to determine directions for optimization improvement design.[Methods]The dy-namic characteristic analysis is conducted concentrated on the coil spring and coil spring cylinder which are key vibration isolation components of the thrust bearing to research the vibration energy leakage.Then,the dynamic model of the coil spring cylinder is established based on both vibration isolation theory and experiment analysis.Moreover,the dynamic characteristic test bench in vertical state is also built up.[Results]The ex-perimental analysis results show that the vibration resonance peak of the coil spring is sharp and smooth,while that of the coil spring cylinder is flat with more harmonic components induced by contact friction.When there is contact friction,there will be additional stiffness and damping,which significantly change the dynamic char-acteristics of the coil spring cylinder.[Conclusion]The dynamic model of the coil spring cylinder is veri-fied by experiments.The dynamic transmission characteristics of the coil spring can be used as an evaluation standard for design improvement.The results of this study can provide theoretical support for the design op-timization and improvement of the vibration-isolation thrust bearing,which can have great significance for practical engineering.