复合故障状态下行星齿轮-转子耦合系统振动响应特性研究

Vibration response characteristics of planetary gear rotor coupling system under composite fault state

目前,国内外学者对齿轮-转子耦合系统的动力学特性进行了研究,但是上述研究均没有考虑行星齿轮-转子复合故障状态。为此,以单级行星齿轮箱为例,通过构建含转子偏心和齿根裂纹故障的行星齿轮-转子耦合系统动力学模型,对复合故障状态下的行星齿轮-转子耦合系统振动响应特性进行了仿真分析和实验研究。首先,采用了集中参数法和Timoshenko梁理论,考虑了时变啮合刚度、支撑刚度、阻尼、陀螺效应、传动轴柔性等因素,建立了含转轴偏心-齿根裂纹复合故障的行星齿轮-转子耦合系统动力学模型;然后,采用了时间历程、频谱、轴心轨迹及相轨迹等方法,并根据其数值分析了不同故障对系统动态特性的影响,研究了偏心状态下裂纹扩展对系统振动响应特性的影响;最后,采用不同裂纹故障测试实验,验证了模型的准确性。研究结果表明:转轴偏心对啮合振动的影响显著,在行星轮系故障特性的分析中不可忽视;偏心-裂纹耦合影响下,系统振动响应由不平衡振动、正常啮合振动、故障冲击振动多源耦合而成,频谱中出现了转频f_( r)、啮合谐波kf _(m)以及复杂边带成分kf _(m)±f _(r)、kf _(m)±f _(r)±nf _(sc),并且随着裂纹程度的加大,调制现象更加明显。该研究结果可以为行星齿轮-转子系统复合故障诊断提供一定的理论依据。

At present,domestic and foreign scholars have conducted research on the dynamic characteristics of gear rotor coupling systems,but none of the above studies have considered the composite fault state of planetary gears and rotors.Therefore,taking a single stage planetary gearbox as an example,a dynamic model of the planetary gear rotor coupling system with rotor eccentricity and root crack faults was constructed,to simulation analyze and experimentally study the vibration response characteristics of the planetary gear rotor coupling system under composite fault conditions.Aiming at the problem of multi-source coupling vibration and composite fault diagnosis in planetary gear transmission systems,a single stage planetary gearbox was executed by dynamic modeling,dynamic characteristics analysis and experimental analysis.Firstly,considering time-varying meshing stiffness,support stiffness,damping,gyroscopic effect,and transmission shaft flexibility,the lumped parameter method and Timoshenko beam theory was used to establish a dynamic model of a planetary gear-rotor coupling system with shaft eccentricity root crack composite fault.Then,the influence of different faults on the dynamic characteristics of the system was analyzed by numerical analysis using time waves,frequency spectrum,axis center orbit and phase diagram.The influence of the root crack propagation of the sun gear on the vibration response characteristics of the system under eccentric state was studied.Finally,the accuracy of the dynamic model was verified by different crack fault experiment.The results show that the influence of eccentricity on meshing vibration is significant and can not be ignored in the analysis of fault characteristics of planetary gear trains.Under the influence of eccentric-crack coupling,the vibration response of the system is composed of unbalanced vibration,normal meshing vibration and fault impact vibration.In the spectrum,there are rotational frequency f _(r),meshing harmonic kf_( m) and complex sideband component kf _(m)±f _(r)、kf _(m)±f _(r)±nf _(sc).With the increase of crack degree,the modulation phenomenon is more obvious.The research results can provide a theoretical basis for the compound fault diagnosis of planetary gear-rotor system.