【作者】 薛光辉；

【导师】 吴淼；

【作者基本信息】 中国矿业大学（北京） ， 机械电子工程， 2010， 博士

【摘要】 振动筛是洗选加工行业的关键设备之一,一旦出现故障将导致整个生产线停工停产,经济损失巨大。因振动筛支撑大梁结构特点,其状态信号的拾取和裂纹故障特征提取困难。目前,国内外尚无有效方法对其进行诊断。本文的研究成果为该问题的解决提供了理论和技术支持,具有重要的理论意义和工程价值。本文根据相似原理研制了振动筛的实验模型,搭建了实验平台；对Harithm估计进行了改进,提出了基于互谱和平均技术的传递函数估计方法,给出了具体的估计算式;研究了在不同裂纹工况下的振动筛大梁传递函数变化规律,提出了基于传递函数的振动筛大梁裂纹故障诊断方法和判据；利用小波降噪理论和方法分析处理了振动筛脉冲激励响应信号,研究了在不同裂纹工况下的振动筛大梁脉冲激励响应信号的功率谱变化趋势,提出了基于FFT和小波变换的振动筛大梁裂纹故障诊断方法和判据,为研究成果的工业应用提供了方法和手段；提出了金属磁记忆检测技术和涡流检测技术相结合的振动筛大梁裂纹故障快速检测方法,并搭建了其检测系统,为振动筛支撑大梁裂纹的现场快速检测提供了理论和技术支持；开展了现场工业性试验,成功诊断和检测出工业应用现场振动筛支撑大梁早期裂纹6处,避免了重大经济损失,产生了良好的社会效益,验证了本文提出的理论和方法的正确性。更多还原

【Abstract】 Vibrating screen is one of the key equipment in washing industry. Once crack fault occurrence of its girder will make the whole production line to shut down, and result in great economic loss. Because of the girder’s structure, it is very difficult to obtain its status signal and extract its crack fault feature. At present, no method can diagnose that fault effectively at home and aboard. The research findings of this paper provide theory and technique supports for that problem, have great theoretical significance and construction value.The experimental model of vibrating screen was designed and experimental platform was built in this paper. Harithm estimation of transfer function (TF) was improved, and an estimation method of TF was put forward based on cross-spectrum and average technique and the concrete estimation formula was proposed. The Regularity for changes of TF of vibrating screen’s girder under various crack conditions was studied and the fault diagnosis method and route criterion on vibrating screen girder crack was put forward based on its TF. The pulse response signal of vibrating screen girder was and processed using wavelet and its power spectrum was analyzed. The fault diagnosis method and route criterion on vibrating screen girder crack was proposed based on FFT and wavelet transform, and give the means for the industry application of study results. The quick test method of vibration girder crack was discussed based on metal magnetic memory testing (MMMT) technique and eddy current testing (ET) technique and its testing system was built. The spot type approval test was carried out and 6 points vibrating screen girder early crack faults were diagnosed and detected out successfully, and which produced appreciable economic and social benefit and verified the correctness of the study results in this thesis.更多还原