基于正交试验的柔性联轴器设计灵敏度分析与优化研究

Design Sensitivity Analysis and Optimization of Flexible Coupling Based on Orthogonal Test

关键词:  联轴器  柔性转子  正交试验  灵敏度分析  优化设计

Key words:  Coupling  Flexible rotor  Orthogonal test  Sensitivity analysis  Optimization design

摘要:

柔性联轴器是某型涡轮热电转换系统的核心部件，对转子动力学特性和工作可靠性有重要影响。本文针对闭式循环热电转换柔性联轴器的结构优化设计问题，开展转子固有频率与临界转速分析，设计柔性联轴器的正交试验，建立转子固有频率同柔性联轴器尺寸参数之间的数学关系；研究转子固有频率随柔性联轴器尺寸参数的变化规律，进行柔性联轴器尺寸参数灵敏度分析。研究表明：转子从起动至额定工况，须经过三阶弯曲模态临界转速，由于第三阶弯曲模态临界转速最高，转子在经过该临界转速时的不平衡响应最大，对转子的危害性也最大；在联轴器结构参数中，柔性杆的直径对转子第三阶弯曲模态的固有频率影响最大；转子第三阶弯曲模态的固有频率随联轴器柔性杆长度的增加而减小，随柔性杆直径、电机端膜片斜度和发动机端膜片斜度的增加而增大。在此基础上，以降低转子在起动过程中经过弯曲模态临界转速时的不平衡响应为目标，对转子柔性联轴器的尺寸参数进行优化。

Abstract:

As one of important components of turbine-based thermoelectric conversion system， the flexible coupling has a significant effect on the dynamic characteristics and reliability of rotor. For the structural optimization problem of flexible coupling applied in the closed cycle power system， the natural frequency and critical speed of rotor is calculated， the orthogonal test of flexible coupling is designed， and the mathematical relationship between the natural frequency of rotor and the dimension parameters of flexible coupling is built. Then， the rules that the natural frequency of rotor change with the dimension parameters of flexible coupling are studied， and the sensitivity analysis of the dimension parameters of flexible coupling is done. The results show that the rotor has to pass three critical speeds with bending mode in the starting process. Because the critical speed corresponding to the third order bending mode is the highest， and correspondingly， the unbalance response of rotor is maximal， the third order bending mode is the most fatal to the rotor. Among the dimension parameters of flexible coupling， the diameter of flexible coupling shaft has the greatest impact on the natural frequency of rotor corresponding to the third order bending mode. The natural frequency of rotor corresponding to the third order bending mode decreases with the increase of length of flexible coupling shaft， and it increases with the increase of the diameter of shaft and the angle of elastic diaphragms near the electric motor and the engine. Finally， in order to reduce the unbalance response of rotor in the starting process， the structural parameters of flexible coupling are optimized.