行星轮系动力学新模型及其故障响应特性研究

A New Dynamic Model of Planetary Gear Sets and Research on Fault Response Characteristics

行星轮系中零部件多、结构复杂,建模难度大。行星轮既自转又公转,导致啮合点到固定在箱体上的传感器之间的距离时刻变化,从而产生振动传递路径时变效应,增加了振动响应的复杂性。现有的动力学模型大多针对正常情况下的行星轮系进行建模,而且未考虑振动传递路径时变效应对振动响应的影响。针对以上不足,推导了行星轮系正常、裂纹及剥落三种情况下的时变啮合刚度算法,考虑振动传递路径时变效应的影响,建立了相应的动力学模型,求解得到行星轮系正常、裂纹及剥落时的动态响应,并分析了它们的频谱特性。搭建了行星齿轮箱试验台以获取振动响应信号,与模型响应信号进行了对比分析,结果验证了动力学模型的准确性,为行星轮系的健康监测提供了理论依据。

Because planetary gear sets contain many components and have complex transmission structures, their dynamic models are difficult to be established. Besides, the planet gears rotate around not only their own centers, but also the center of the sun gear, and the time-varying distances from gear meshing points to the fixed transducers add the complexity of vibration response. Most of the dynamic models reported in current literature are under healthy conditions, and the time-varying effects of transmission paths are ignored in these models. Aiming at these shortcomings, a new dynamic model of planetary gear sets is established, in which the time-varying mesh stiffness under healthy, cracked and spalling conditions in planetary gear sets is calculated respectively, and the transmission paths are considered. Using this model, gear dynamic responses are obtained and compared with vibration signals captured from a planetary gearbox test rig. The comparison verifies the validity of the dynamic model, and provides a theory basis for health monitoring of planetary gear sets.