【作者】 宋高峰；

【导师】 杨兆建；

【作者基本信息】 太原理工大学 ， 机械工程， 2013， 博士

【摘要】 多轮盘转子系统的结构比较复杂,在运行过程中,可能由于外加扭矩激励、初始轴弯曲等因素的影响,导致整个转子系统出现故障。目前,多位学者已开展了相关研究。然而,这些研究还有待深入。本文在此基础上,做了以下几方面的研究：(1)在传统扭矩激励表达式的基础上,对其进行了改进。分别对扭矩激励表达式改进前后仿真和试验结果进行了对比分析,结果表明：改进后扭矩激励表达式能更准确的反应实际转子系统扭矩激励的加载。(2)在改进扭矩激励表达的基础上,考虑了非线性油膜力和弹性支承对多跨多轮盘转子系统的影响,建立了基于扭矩激励的多跨多轮盘转子系统模型及动力学方程,通过仿真和试验的方法分别研究了不同性质(线性、暂态)扭矩激励对多跨多轮盘转子系统各跨转子弯振的影响。结果表明：在不同性质扭矩激励(线性、暂态)的作用下,多跨多轮盘转子系统各跨转子振动幅值均未出现变化,而振动平衡位置出现向下偏移现象,并且各跨转子X向偏移量要明显小于Y向。(3)在改进扭矩激励表达的基础上,考虑了弹性联轴器对多跨多轮盘转子系统的影响,建立了多跨多轮盘转子系统扭矩激励传递模型,推导了轴承负荷对扭矩激励的敏感度矩阵。通过仿真和试验的方法分别研究了多跨多轮盘转子系统不同性质(线性、暂态)扭矩激励的传递特性。结果表明：多跨多轮盘转子系统不同性质(线性、暂态)扭矩激励在X向和Y向的传递特性均不同,在同一扭矩激励作用下,多轮盘转子系统各支承X向和Y向轴承负荷对扭矩激励的敏感性响应不同。(4)考虑了初始轴弯曲故障对多轮盘转子系统的影响,建立了具有初始轴弯曲的多轮盘转子系统模型及动力学方程,仿真分析了初始弯曲量、偏心距及阻尼比对多轮盘转子系统弯振的影响。通过小波和非线性流行方法实现了初始轴弯曲故障试验信号的特征提取及信号辨识。将仿真分析结果与提取的初始轴弯曲故障信号进行对比分析,并提出了具有初始轴弯曲的转子系统试验修正方程。(5)在小波降噪和数学形态学降噪的基础上,提出了小波形态滤波法。分别采用形态学降噪和小波形态滤波法对仿真信号和轴承负荷试验信号进行了降噪处理,降噪结果很好地验证了小波形态滤波法对轴承负荷信号降噪的有效性。通过本文的研究,可以更为清晰地明白扭矩激励对多跨多轮盘转子系统的影响,更为清楚地认识到扭矩激励传递、初始轴弯曲故障信号以及轴承负荷信号的特点,为抑制扭矩激励干扰、转子系统典型故障诊断、提高转子系统试验信号采集效率奠定了坚实的基础。更多还原

【Abstract】 The structure of the multi-disk rotor system is more complex. The effect of the torsional excitation or residual shaft bow may lead failure of the rotor system in operation. Recently, a number of researchers have conducted some studies in this field. However, these studies have not yet to be in-depth. In this paper, some studies have been carried out as followed.(1) The torsional excitation expression was improved, and the results of the simulation and the test before and after the torsional excitation improved were compared and analysed, respectively. The results indicate that the simulation is more close to the actual one after improving the torsional excitation expression.(2) Based on the improved torsional excitation expression, the model and the dynamic equation of the multi-disk rotor system were established by considerring the effect of the nonlinear oil film force and the elastic support. The effect of the different nature (nonlinear and transient) torsional excitation to the multi-disk rotor system was studied by simulation and test, respectively. The results indicate that the vibration amplitudes of multi-disk rotor system have no change, and the phenomenon of vibrational equilibrium position downward shift was appeared. Also, the offset of each cross rotor in X direction is less than the one in Y direction, obviously.(3) Based on the improved torsional excitation expression, the transfer model of torsional excitation in multi-disk rotor system was established by considering the effect of the flexible coupling, and the sensitivity matrix of the bearing load to torsional excitation was derivated. The transfer characteristics of different nature (nonlinear and transient) torsional excitation in multi-disk rotor system were studied by simulation and test, respectively. The results indicate that the transfer characteristics of different nature (nonlinear and transient) torsional excitation in multi-disk rotor system in X and Y direction were difference, and with the effect of the same torsional excitation, the sensitivity responses of the bearing load to torsional excitation in X direction and Y direction were difference.(4) The model of the multi-disk rotor system with residual shaft bow was established, and the effect of the residual shaft bow, eccentricity, damping ratio to multi-disk rotor system was simulated and analysed. The feature extraction and signal recognition of the residual shaft bow fault signal were achieved, and the results of the simulation and the test fault signal of residual shaft bow were compared. The test modified equation of the rotor system with residual shaft bow was proposed.(5) Based on the noise reduction methods of wavelet and mathematical morphology, the method of wavelet-morphology was proposed. The signals of the simulation and the test were denoised by the noise reduction methods of mathematical morphology and wavelet-morphology, respectively. The results indicate that the noise reduction method of wavelet-morphology can be well used to denoise the bearing load signals.After the studies in this paper, the effect of torsional excitation to multi-disk rotor system can be well known, and the characteristics of torsional excitation, residual shaft bow fault signal, bearing load signal can be obtained. This paper lays the foundation for suppressing torsional excitation interference, rotor system typical fault diagnosis and improving the efficiency of bearing load signal acquisition.更多还原