多轴系耦合作用下齿轮系统转子裂纹故障的振动特性研究

Study on the Vibration Characteristics of Gear System with Rotor Crack Faults under Multi-axis Coupling

为了探究多轴系耦合齿轮系统中的转子裂纹故障与单轴系转子裂纹故障振动响应特性的异同点,基于Jones轴承建模理论,建立滚动轴承的拟静力学模型;利用Timoshenko梁单元建立传动轴的有限元模型;考虑时变啮合刚度、齿轮传递误差、陀螺效应等因素,利用集中参数法建立齿轮副的动力学模型。将轴承、传动轴与齿轮副模型进行集成,建立齿轮系统非线性动力学模型;利用能量释放率理论与应力强度因子为零法分析裂纹转子单元的呼吸效应,利用Newmark-β数值积分法对转子裂纹故障进行动力学仿真,研究转子裂纹故障的振动响应特征。结果表明:与单轴转子系统转子裂纹的振动响应特征不同,当齿轮系统发生转子裂纹故障时,由于齿轮啮合的引起的耦合效应及转子裂纹引起的呼吸效应,时域响应表现出明显的幅值调制现象,频域中转频及其2倍频幅值增加明显,在啮合频率处伴有明显的边频带。研究结果可为齿轮系统转子裂纹故障的监测与诊断提供理论基础。

The objective of this article is to explore the differences of vibration response characteristics between the single-axis rotor and the multi-axis coupled gear system with rotor crack faults.A quasi static model of rolling bearings is established based on Jones bearing modeling theory.Timoshenko beam elements are used to establish the finite element model of the transmission shaft.Considering the time-varying meshing stiffness,gear transmission error,gyroscopic effect etc.,the dynamic model of the gear pair is established by using lumped parameter method.The bearings,drive shaft and gear pair model are integrated to build the nonlinear dynamic model of the gear system.The energy release rate theory is used to analyze the breathing effect of the cracked rotor.The vibration response characteristics of the rotor crack faults are simulated by Newmark-β numerical integral method.The results show that when the rotor crack faults occur,the time-domain response shows obvious amplitude modulation phnomenon due to the coupling effect induced by gear meshing and the breathing effect induced by rotor crack faults.The amplitudes of the rotational frequency and the octave rotational frequency increase significantly.There are obvious sidebands at the meshing frequency.The research results provide a theoretical basis for the monitoring and diagnosis of gear transmission system with rotor crack faults.