首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   19篇
  完全免费   5篇
  机械仪表   24篇
  2017年   2篇
  2016年   1篇
  2015年   2篇
  2014年   2篇
  2013年   2篇
  2012年   3篇
  2011年   6篇
  2010年   3篇
  2008年   1篇
  2006年   1篇
  2005年   1篇
排序方式: 共有24条查询结果,搜索用时 52 毫秒
1.
滚动轴承故障检测的改进包络分析法   总被引:10,自引:3,他引:7  
石林锁 《轴承》2006,(2):36-39
提出了一种基于连续小波变换和谱峭度分析的改进包络分析方法,并将其应用于滚动轴承的故障检测之中。该方法的核心是自动确定由轴承缺陷所引起的共振频率所在的频带,自动构建最佳包络来进行故障诊断,该方法已成功地应用到了对故障轴承振动信号的仿真和实测,并取得了满意的结果。  相似文献
2.
基于峰度的电力变压器铁芯松动故障在线监测方法   总被引:3,自引:1,他引:2  
本文提出一种对电力变压器铁芯松动故障进行在线监测和估计的方法.通过改变变压器铁芯的压紧力得到模拟松动故障情况下的铁芯振动信号,使用谱峰度方法验证并分析了变压器铁芯振动信号中高频分量的冲击特性,在此基础上采用小波变换对铁芯振动信号进行分解,对分解得到高频分量计算其峰度值并用以监测铁芯压紧力的减小趋势.对实验变压器不同测点的多组数据分析表明,谱峰度能有效检测铁芯振动信号中的较高频率冲击成分及铁芯压紧力发生较大变化的情况,铁芯振动信号小波域中高频成分的峰度值能够很好的反映出铁芯压紧力变化的趋势.本方法准确的表述了铁芯振动信号中与松动故障相关的统计特性,为电力变压器铁芯的故障监测提供了一种可行的方法.  相似文献
3.
This paper presents a simulation model for a gearbox test rig, in which a range of bearing faults can be implemented. Bearing faults sometimes manifest themselves by their interaction with meshing gears, and to simulate this it is necessary to model a whole system of gears and shafts supported in bearings. This has now been done for an experimental test rig through the incorporation of a time-varying, non-linear stiffness bearing model into a previously developed gear model. The incorporated bearing model is based on Hertzian contact theory, which relates the raceway displacement to the bearing load, and also accounts for the slippage between the elements. It has the capacity to model localised spalls (inner race, outer race and rolling elements), which are discussed in this part of the paper and extended inner and outer race faults (rough surfaces), which are discussed in part II. Even though the whole gearbox has not been modelled in detail, the non-linear time-varying gear-meshing operation is modelled in some detail. Both simulated and experimental localised fault signals (acceleration signals) were subjected to the same diagnostic techniques; namely spectrum comparisons, Spectral Kurtosis (SK) analysis and envelope analysis. The processed simulated signals showed a similar pattern to that observed in their measured counterparts and were found to have a characteristic, referred to in the literature as double pulses, corresponding to entry into and exit from the localised fault. The simulation model will be useful for producing typical fault signals from gearboxes to test new diagnostic algorithms, and possibly prognostic algorithms.  相似文献
4.
The narrowband amplitude demodulation of a vibration signal enables the extraction of components carrying information about rotating machine faults. However, the quality of the demodulated signal depends on the frequency band selected for the demodulation. The spectral kurtosis (SK) was proved to be a very efficient method for detection of such faults, including defective rolling element bearings and gears [1]. Although there are conditions, under which SK yields valid results, there are also cases, when it fails, e.g. in the presence of a relatively strong, non-Gaussian noise containing high peaks or for a relatively high repetition rate of fault impulses.In this paper, a novel method for selection of the optimal frequency band, which attempts to overcome the aforementioned drawbacks, is presented. Subsequently, a new tool for presentation of results of the method, called the Protrugram, is proposed. The method is based on the kurtosis of the envelope spectrum amplitudes of the demodulated signal, rather than on the kurtosis of the filtered time signal. The advantage of the method is the ability to detect transients with smaller signal-to-noise ratio comparing to the SK-based Fast Kurtogram. The application of the proposed method is validated on simulated and real data, including a test rig, a simulated signal, and a jet engine vibration signal.  相似文献
5.
Blind separation of vibration components: Principles and demonstrations   总被引:1,自引:0,他引:1  
Blind source separation is the issue of recovering the various independent sources exciting a system given only the measurements of the outputs of that system. It has recently become the focus of intensive research work due to its high potential in many applications. However when it comes to vibration signals, blind source separation faces a number of difficulties which seriously hinder its feasibility. In this paper we first draw a list of these difficulties. We then propose to somehow lessen the ambitions of BSS to more realistic goals, and in particular to separate vibration signal into contributions of (1) periodic, (2) random stationary, and (3) random nonstationary sources. Although not ideal, such a separation can provide substantial information in many practical cases of interest. Towards this aim we propose two robust separation techniques based on the short-time Fourier transform. They are perfectly suited to handle convolutive mixtures of sources and they lead to fast and efficient implementation.  相似文献
6.
基于SVD降噪和谱峭度的滚动轴承故障诊断   总被引:1,自引:0,他引:1  
提出将奇异值分解(SVD)和谱峭度结合的滚动轴承故障诊断方法.首先,将原始振动信号构造为Hankel矩阵,进行奇异值分解,并利用奇异值差分谱进行有效的消噪;然后,利用谱峭度所得的峭度图选择最佳的带宽和中心频率对降噪后的信号进行带通滤波;最后,对滤波后的信号进行平方包络和Fourier变换得到包络解调谱,即可实现故障特征的提取.对滚动轴承故障试验信号的分析表明,该方法可以有效地提取故障特征频率,实现故障诊断.  相似文献
7.
The application of Acoustic Emission (AE) technology for machine health monitoring is gaining ground as power tool for health diagnostic of rolling element bearing. This paper provides an investigation that compares the applicability of AE and vibration technologies in monitoring a naturally degraded roller bearing. This research is the first known attempt investigating the comparative effectiveness of applying the Kurtogram to both vibration and AE data from a defective bearing.  相似文献
8.
The detection of improperly lubricated bearings from vibration patterns is a difficult task especially when records from short operating periods are available. This is exactly the case of end-quality assessment systems. This problem has been addressed by applying both cyclostationary analysis and spectral kurtosis for the selection of a frequency band in which variations in vibration patterns are most expressed. The approach was evaluated on a test-set comprising 63 electrical motors with fault-free and 21 with improperly lubricated bearings. The results reveal that improper lubrication is expressed as increase in the spectral components at bearing cage and ball spin frequency.  相似文献
9.
基于谱峭度和AR模型的滚动轴承故障诊断   总被引:1,自引:0,他引:1  
提出基于自回归(Autoregressive,简称AR)预测滤波的谱峭度分析方法,将其应用于滚动轴承的早期故障诊断。通过结合AR预测滤波器提取轴承故障信号共振衰减成分的特性,利用谱峭度方法对AR预测滤波器滤波后的信号进行处理,实现了滚动轴承早期微弱故障的识别。通过滚动轴承的疲劳全寿命加速实验获取滚动轴承的自然故障信号,克服了传统轴承故障诊断人工加工故障的不足。通过试验数据的分析表明,基于AR预测滤波的谱峭度方法不仅能够消除干扰成分提取故障特征,还能增加谱峭度方法的稳定性。  相似文献
10.
Time–frequency analyses are commonly used to diagnose the health of bearings by processing vibration signals captured from the bearings. However, these analyses cannot be guaranteed to be robust if the bearing signals are overwhelmed by large noise. Ensemble empirical mode decomposition (EEMD) was developed from the popular empirical mode decomposition (EMD). However, if there is large noise, it may be difficult to recover impulses from large noise. In this paper, we develop a hybrid signal processing method that combines spectral kurtosis (SK) with EEMD. First, the raw vibration signal is filtered using an optimal band-pass filter based on SK. EEMD method is then applied to decompose the filtered signal. Various bearing signals are used to validate the efficiency of the proposed method. The results demonstrate that the hybrid signal processing method can successfully recover the impulses generated by bearing faults from the raw signal, even when overwhelmed by large noise.  相似文献
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号