Abstract

Condition monitoring of gearboxes running under nonstationary regimes continue to be an important source of interest for industrialists and researchers. Despite the diversity of models in the literature, none allows simulating all cases of machine operations and failures modes in nonstationary regimes. This paper will discuss through a modeling approach how speed and load variations will influence the dynamic response of a single-stage gearbox supported by four rolling-element bearings, in the healthy case and in the case of gear and/or bearing defects. Combining 72 degrees of freedom and taking into consideration meshing and bearing nonlinear excitations, the proposed model allowed to compute the dynamic behavior of the real system for the case of gear tooth crack defect, pinion eccentricity defect, and the three localized bearing defects (outer race, inner race, and ball defects). Fast Fourier transform, Squared envelope spectrum, Short-time Fourier transform, and Kurtogram was used to reveal the vibration signature of the introduced defects under the different operating modes. A special envelope spectrogram was also designed to reveal the bearing defect frequencies variations in the case of a variable-driven speed.

摘要

在非平稳状态下运行的变速箱状态监测仍然是工业家和研究人员关注的重要来源。尽管文献中模型的多样性，但没有一个模型可以模拟非平稳状态下的机器运行和故障模式的所有情况。本文将通过一种建模方法来讨论，在健康的情况下以及在齿轮和/或轴承有缺陷的情况下，速度和负载变化将如何影响由四个滚动轴承支撑的单级齿轮箱的动力响应。结合72个自由度并考虑啮合和轴承非线性激励，该模型可以计算真实系统在齿轮齿裂纹缺陷，小齿轮偏心缺陷，以及三个局部轴承缺陷（外圈，内圈和滚珠缺陷）。快速傅立叶变换，平方包络谱，短时傅立叶变换和Kurtogram被用来揭示在不同操作模式下引入的缺陷的振动特征。还设计了特殊的包络声谱图，以揭示在变速驱动的情况下轴承缺陷频率的变化。