摘要
引入高阶统计量诊断曲轴轴承磨损故障,在EQ6100汽油发动机上模拟设置四种曲轴轴承间隙,并应用双干谱、双谱对振动信号进行了分析比较,结果显示双谱有效地抑制了噪声影响,较好地对曲轴轴承四种磨损状态进行了分类和识别,并揭示了非线性相位耦合随曲轴轴承磨损状态的变化规律;而运用双谱沿频率ω1=ω2的对角切片提取了曲轴轴承磨损故障诊断的特征参数,并有效地诊断了该故障.
Vibration signals caused by different main bearing clearances are not stationary and time-variant.It is difficult to detect early and diagnose by means of traditional methods.A new method based on bispectral analysis for main bearing faults of the engine is presented.The different clearances of the main bearing of the previously designed EQ6100 engine.Vibration signals are obtained from engine block.Applying the bispectrum and bicoherence analysis to the vibration signals,the fault features are extracted.The diagonal slice of the bispectrum can clearly show different working conditions,which makes much easier recognition.Research result proves that this method can reduce noise and describe the nonlinear phase couple for the engine faults.
