共查询到19条相似文献,搜索用时 140 毫秒
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将常规的双谱分析与倒谱技术相结合,提出了基于倒双谱的齿轮箱故障诊断方法。首先对齿轮箱振动信号进行双谱分析,以消除噪声的影响,再计算双谱的倒谱,对信号进行倒双谱分析,可有效提高信噪比,提取轴承的故障特征。齿轮箱轴承内外圈故障振动试验信号的研究结果表明,倒双谱分析能有效地诊断轴承的故障。 相似文献
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矢双谱分析及其在机械故障诊断中的应用 总被引:4,自引:0,他引:4
双谱分析由于可以有效提取信号中的非线性特征被广泛应用于转子故障诊断。但常规双谱分析是以单通道信号为研究对象,不能全面地反映转子系统的非线性特征,存在着信息遗漏的问题,而且由同一截面的两个通道信号得出的分析结论会不一致。为解决这个问题,以全矢谱分析方法为基础提出矢双谱信号分析的新方法。矢双谱是融合了同一截面上双通道信号的幅值信息而保留了各自的相位信息的全矢双谱分析方法,能够真实地反映转子运转所包含的各种信息,且能满足分析结论的一致性要求。给出矢双谱的定义与算法,通过仿真和齿轮箱故障试验,研究结果表明,该方法能够更加全面地反映信号中所包含的非线性特征信息,分析结论具有一致性和可信性,从而提高智能故障诊断的准确性。 相似文献
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开展了固体润滑轴承组件的真空加速寿命试验,以验证固体润滑轴承组件的设计是否满足在轨寿命要求。研究了MoS2基薄膜固体润滑轴承组件在小角度摆动情况下的寿命。试验采用4对轴承模拟在轨±6°连续往复摆动,通过检测轴承组件工作时的摩擦力矩、电机电流和轴承温升判断轴承运行状态。结果显示,寿命试验运行正常,累计摩擦次数为6.2×10~7次。寿命试验后对轴承进行了尺寸精度和旋转精度复测,然后对轴承组件进行了解剖分析。复测结果显示,轴承尺寸精度和旋转精度与试验前一致,轴承润滑状态良好。试验结果验证了固体润滑轴承组件寿命满足在轨任务要求,为其它空间相机小角度摆动的扫描机构固体润滑轴承组件的长寿命设计提供了依据。 相似文献
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针对一种新型三瓣式气体箔片轴承,考虑接触界面库仑摩擦后提出了相应的刚度计算模型,并通过求解动压气体润滑Reynolds方程,计算并分析了轴承的静态特性和动态特性。研究了转速、载荷、轴承预载和轴承安装角对该轴承静动态特性的影响。静态特性方面,轴承预载可以较大程度地提高承载能力,且高转速下承载能力更强;安装角度对承载能力的影响呈正/余弦规律变化,且随着转速增大,最大承载能力所对应的安装角不断减小,并最终稳定在70°。动态方面,轴承动态直接刚度随预载增大而显著增大,阻尼变化较小;轴承动态刚度和阻尼随安装角的变化也表现为正/余弦规律,且随安装角的增大,两直接刚度和两直接阻尼分别呈异步变化趋势。 相似文献
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针对传统双谱分析从理论上仅能抑制高斯噪声,但对非高斯噪声无能为力的不足,提出了一种利用经验模式分解(empirical mode decomposition,简称EMD)和双谱分析的故障特征提取方法,并应用于滚动轴承故障诊断中。首先,对信号进行EMD分解;其次,利用能量相关法去除EMD分解过程中出现的伪本征模态分量(intrinsic mode function,简称IMF);最后,对得到的真实IMF进行双谱分析提取故障特征。仿真和实验结果表明,所提出的方法优于功率谱分析和传统双谱分析,能够更有效地提取强噪声背景下的机械故障特征信息,为滚动轴承的故障特征提取提供了一种新的方法。 相似文献
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针对1580 PC热板带连轧机油膜轴承在装拆与使用过程中的锥套损伤问题,建立锥套装配的边界元力学模型及边界条件。利用三维弹塑性接触问题边界元法定量分析轧机油膜轴承锥套与轧辊辊颈过盈装配过程中的变形和载荷特性,通过设定不同加载模型的参数,对锥套装拆过程进行数值模拟。讨论油膜轴承偏载时锥套接触应力和变形对锥套与辊颈损伤的影响,得出装拆过程中不同胀型压力和轴向推力条件下的应力和应变变化规律,找出导致锥套损伤的根本原因,给出防止锥套与辊颈装配过程损伤的具体改进措施。利用制造出的两台轧机油膜轴承样机试验验证理论分析结果的正确性,并且找到油膜轴承损伤的根本原因。 相似文献
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提出一种基于高阶统计量特征和BP神经网络相结合的滚动轴承故障分类方法。以滚动轴承的高阶统计量(双谱、三阶累积量)以及一些常见的无量纲指标作为轴承故障特征输入,以BP神经网络作为分类器,成功地对滚动轴承4种不同的故障进行了分类。对比RBF神经网络,尽管BP神经网络的训练速度不快,但分类效果良好。研究表明,高阶统计量和BP神经网络相结合的滚动轴承分类方法是有效的。 相似文献
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阶比双谱及其在旋转机械故障诊断中的应用 总被引:1,自引:0,他引:1
双谱分析是处理非线性、非高斯信号的有力工具,然而,它是以分析恒频振动的稳态信号作为前提条件的,对分析旋转机械中广泛存在的变频振动信号(如旋转机械升降速信号)是无能为力的。而阶比双谱是一种分析变频振动信号的新方法,它将非稳态信号按等转角间隔进行采样,得到阶域中的稳定信号,再进行双谱分析;仿真显示该方法优于阶比谱和传统双谱。最后,将该方法成功地应用到旋转机械升降速过程的故障诊断中,实验结果表明该方法是有效的,阶比双谱可很好地分析机械振动的非线性非平稳信号。 相似文献
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The vibration signals of rotating machinery present a strongly non-linear and non-Gaussian behavior, and bispectrum is well suitable to analyze this kind of signals. Due to modulation or smearing, it is hard to extract the accurate frequency-based features from the bispectrum. A bispectral distribution for machinery fault diagnosis is developed in this paper. The binary images extracted from the bispectra are taken as features to construct the target templates, then, the nearest template classifier is constructed to achieve pattern recognition and fault diagnosis. The computing speed of this method is very high because the proposed algorithm just calculates the number of “1”. Finally, roller bearing and gear fault diagnosis are performed as examples, respectively, to verify the feasibility of the proposed method. 相似文献
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IGOR SIMONOVSKI MIHA BOLTE
AR JANEZ GRADI
EK EDVARD GOVEKAR IGOR GRABEC ANTON KUHELJ 《Mechanical Systems and Signal Processing》2002,16(6):1093
A higher order spectral analysis of the cutting process is presented with the purpose of indicating the chatter. First, the information contents of the cutting force components are compared using a bicoherence estimator. The analysis reveals that all three components are equally informative. Additionally, the magnitude bispectrum's and the bicoherence's estimator efficiency in identifying chatter is studied with respect to three different cutting regimes. In two of the regimes, which are denoted as strong and weak chatter, several interactions between spectral components in both the magnitude bispectra and bicoherence estimators are outstanding. This suggests the presence of quadratic-type non-linearities in the dynamics of chatter. In the third chatter-free regime of cutting, the magnitude bispectrum and bicoherence estimators reflect almost insignificant interactions between spectral components. It is shown that both magnitude bispectrum and bicoherence estimators identify this reduction in the quadratic-type non-linearities. However, using the magnitude bispectrum is numerically slightly more efficient when compared to the bicoherence estimator, since calculating the magnitude bispectrum is numerically less demanding. Since only short time series of data are available for on-line characterization, the amount of averaging is often insufficient when calculating estimators. This leads to unreliable values of the estimators. In the present work we try to overcome this problem by utilising a combination of a standard segment and additional inner triangle averaging. This approach decreases the sensitivity of the estimator values to the small changes of input parameters. The presented combination is then applied in the bicoherence analysis of the cutting process. 相似文献
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Vibrations and sounds generated by reciprocated machines or by their parts strongly depend on the rotation speed of the main shaft of the tested reciprocating system. At the testing or at common performance of the reciprocated machines, their rotation speed is usually changing. With regard to this fact, signals produced by reciprocating machines are non-stationary ones. Therefore, conventional time-invariant methods of their spectral or bispectral analysis are frequently unable to provide meaningful results. In order to solve this problem in the field of polyspectral signal analysis, the order bispectrum analysis is proposed in this contribution. This approach is based on the bispectrum estimation from the signal which is a function of the angle of roll of the main shaft of reciprocated machine. A digital representation of this signal can be obtained by resampling of the signal conveniently sampled in the time domain. The advantages of the order bispectrum application in comparison with that of the conventional bispectrum approach is illustrated based on the example of an engine set classification. 相似文献