基于传动机理分析的行星齿轮箱振动信号仿真及其故障诊断

Vibration Signal Simulation and Fault Diagnosis of Planetary Gearboxes Based on Transmission Mechanism Analysis

行星齿轮传动结构一般由太阳轮、行星轮、内齿圈和行星架等组成,相比定轴齿轮传动,其结构更加复杂。行星齿轮箱中,多对齿轮啮合引起的振动相互叠加、各啮合点与传感器之间的传递路径周期性变化等特点使其故障诊断比定轴齿轮箱难度更大。为了准确诊断行星齿轮箱故障,分析其传动机理、建立振动信号仿真模型尤为重要。针对这一需求,将行星齿轮箱内部的多个啮合'分而治之',分析每个啮合成分的传递路径,综合考虑各啮合成分之间的相位差,建立行星齿轮箱的振动信号仿真模型,得到了不同齿轮故障时的振动响应信号,通过对比正常与故障信号的不同特点,实现行星齿轮箱的故障诊断。该模型的优势在于综合考虑了行星齿轮箱内部的多对啮合以及它们之间的相位关系、行星轮公转引起的时变传递路径以及齿轮故障时的调制等因素。为了验证该信号仿真模型,在行星齿轮箱试验台上采集了正常、太阳轮和行星轮局部故障的振动信号,与仿真模型的信号进行了分析比较,归纳了行星齿轮箱齿轮局部故障时的振动信号特点。

Planetary gear transmission structures, consisting of sun gear, planet gears, ring gear, carrier etc., are more complex than fixed-axis gear transmission structures. In planetary gearboxes, the vibration responses of multiple gear pair meshing couple with each other, and the vibration transmission paths from gear meshing points to the fixed transducers are time-varying. Therefore, fault diagnosis of the planetary gearboxes is more difficult compared to that of fixed-axis gearboxes, in which the vibration simulation models are very important. By analyzing the transmission paths of each meshing vibration and synthetizing the phase differences between different meshing vibrations, vibration simulation models of the planetary gearboxes are constructed and the vibration signals based on the models are obtained. By comparing the signal characteristics of the faulty condition with the healthy one, faults of the planetary gearboxes can be diagnosed. The constructed models are characterized by considering multiple gear pair meshing and their phase relations, time-varying vibration transmission paths, modulations due to gear faults, etc. To test the proposed models, the vibration signals are measured from a planetary gearbox test rig under the healthy condition, the sun gear with a cracked tooth and a planet gear with a cracked tooth, respectively. The fault characteristics of the planetary gearboxes are summarized based on the comparisons of the vibration signals between the models and the experiments.