基于阶频谱相干的变转速滚动轴承内外圈复合故障特征分离提取  

Feature separation and extraction of compound faults of inner and outer rings of rolling bearings at variable speed based on order-frequency spectral coherence

作　　者：杨新敏 郭瑜[1] 华健翔 YANG Xinmin;GUO Yu;HUA Jianxiang(Faculty of Mechanical and Electrical Engineering,Kunming University of Science and Technology,Kunming 650500,China)

机构地区：[1]昆明理工大学机电工程学院,昆明650500

出　　处：《振动与冲击》2022年第22期211-218,共8页Journal of Vibration and Shock

基　　金：国家自然科学基金(52165067);云南省重大科技专项计划(202002AC080001)。

摘　　要：针对变转速工况下复合故障相互耦合,较弱的故障特征易受干扰,难以识别的问题。该研究提出一种基于阶频谱相干(order-frequency spectral coherence, OFSCoh)解调频带确定的复合故障特征分离提取方法,应用于变转速工况下滚动轴承复合故障诊断。首先,对信号进行OFSCoh计算;然后,以轴承内、外圈对应的故障阶次区间分别对OFSCoh函数进行积分获得特征频带谱,将特征频带谱中最大值对应的频率确定为解调频带中心频率,以最大转频对应的3倍故障频率作为解调带宽;分别对信号进行带通滤波,并计算其改进包络谱(improved envelope spectrum, IES),从而实现轴承复合故障特征分离提取。仿真和试验证明了该方法的有效性。Aiming at the problem that compound faults are coupled with each other and weak fault features are easy to be interfered and difficult to be identified under the condition of variable speed. A method of compound fault features separation and extraction based on the demodulation frequency band determination of order-frequency spectral coherence(OFSCoh) was proposed, which was then applied to compound faults diagnosis of rolling bearings under variable speed condition. Firstly, the signal was calculated by the OFSCoh method. Then, the characteristic frequency band spectrum was obtained by integrating the OFSCoh in the failure order interval of the inner and outer race of the bearing, and the frequency corresponding to the maximum value in the characteristic frequency band spectrum was determined as the center frequency of the demodulation band, and the maximal speed frequency corresponding to 3 times of the fault frequency was taken as the bound of bandwidth. Finally, the signal was filtered by a band pass, and the improved envelope spectrum(IES) was calculated, so as to realize the separation and extraction of bearing compound fault features. The simulation and experiment verify the effectiveness of the proposed method.

关 键 词：滚动轴承 变转速工况 阶频谱相干(OFSCoh) 特征频带谱 复合故障 

分 类 号：TH17[机械工程—机械制造及自动化] TH133.332