滚动轴承故障声发射波形流信号特性实验研究

发布时间：2018-07-09 18:27

  本文选题：滚动轴承 + 声发射波形流信号　； 参考：《东北石油大学》2017年硕士论文

【摘要】：滚动轴承是一种精密的机械基础件,广泛应用于各种机械设备,其运行状态好坏直接影响到整台机器能否安全运行。滚动轴承处于故障状态时,运行过程有异常声信号的产生,可利用声发射检测方法对滚动轴承状态进行检测。与振动信号相比,声发射信号频率范围较宽,利用其高频段信号进行故障诊断,可以有效地抑制其他低频干扰信号。然而传统的声发射技术采集的信号是间断性、非连续的,采集不到完整的周期性信号,声发射波形流技术能够将波形数据连续的记入计算机的物理内存,以高采样率完成固定长度的周期性声发射信号采集,可以实时、长时间的采集连续型声发射信号。另外,采用声发射波形流技术进行信号分析时,既可查看多周期的波形流数据,同时也可对局部波形流进行放大分析研究。滚动轴承的声信号具有周期性,所以采用此方法对滚动轴承信号进行采集能够体现波形流技术的优势。本文以型号为N205EM和NU205EM的滚动轴承为研究对象,对滚动轴承主要故障形式及成因进行分析,计算滚动轴承固有频率,通过实测频率与滚动轴承固有频率对比判断滚动轴承故障的发生及类型。搭建滚动轴承故障模拟测试系统,用电火花加工的方法在滚动轴承的外圈、内圈及滚动体进行人为破坏,模拟滚动轴承的外圈故障、内圈故障和滚动体故障,利用滚动轴承故障模拟测试系统采集滚动轴承不同状态不同转速下的声发射波形流信号和振动信号。通过时域分析对滚动轴承振动信号和声发射波形流信号进行对比,在转速较低的情况下,振动信号较灵敏。随着转速的增加,声发射波形流信号呈现出明显的周期特性,能够更好的表征故障,可对固定周期的声发射波形流信号进行分析判断轴承故障的发生。运用短时能量法对滚动轴承声发射波形流信号进行分析,采用声发射波形流技术采集的声信号在转速较高时周期性明显,可通过短时能量法初步判断滚动轴承故障的产生。运用谱分析对滚动轴承声发射波形流信号和振动信号进行分析,运用包络谱分析和功率谱分析时能够判断故障的产生,但由于噪声的影响,不能提取滚动轴承运转过程中的实测频率,因此不能准确判断故障的具体类型。利用结合包络谱分析的双谱分析对滚动轴承故障的声发射波形流信号进行分析诊断。通过双谱分析三维图、等高线图及切片图,得到滚动轴承运转过程中不同故障类型的峰值频率,与滚动轴承不同故障固有特征频率的理论值之间具有很好的一致性。可实现滚动轴承不同故障的早期诊断。
[Abstract]:Rolling bearing is a kind of precise mechanical foundation, which is widely used in all kinds of mechanical equipment. The running state of the rolling bearing directly affects the safe operation of the whole machine. When the rolling bearing is in the state of failure, the abnormal sound signal is produced in the running process. The sound emission detection method can be used to detect the state of the rolling bearing. The frequency range of the acoustic emission signal is wide, and the fault diagnosis can effectively suppress the other low-frequency interference signals. However, the traditional acoustic emission signals are discontinuous and discontinuous, and the complete periodic signals are not collected. The acoustic emission waveform flow technique can keep the continuous recording of the waveform data. In the physical memory of the computer, the periodic acoustic emission signals of fixed length are collected at high sampling rate, and the continuous acoustic emission signals can be collected in real time and for a long time. In addition, when the acoustic emission waveform flow is used to analyze the signal, it can not only view the data of the multi cycle waveform flow, but also magnify the local waveform flow. Research. The sound signal of rolling bearing is periodic, so using this method to collect the signal of rolling bearing can reflect the advantage of wave flow technology. This paper takes the rolling bearing of N205EM and NU205EM as the research object, analyses the main fault forms and causes of rolling bearing, calculates the natural frequency of rolling bearing, and through the actual The frequency of measurement and the natural frequency of rolling bearing judge the occurrence and type of rolling bearing fault, build a rolling bearing fault simulation test system, use the method of EDM to destroy the outer ring, inner ring and rolling body of the rolling bearing, simulate the outer ring of the rolling bearing, the inner ring fault and the rolling body fault, and use the rolling shaft. The bearing fault simulation test system collects the acoustic emission wave and vibration signals of the rolling bearings at different speeds and different speeds. Through the time domain analysis, the vibration signals of the rolling bearings and the acoustic emission waveform flow signals are compared. The vibration signals are more sensitive when the rotational speed is low. With the speed increasing, the acoustic emission waveform flow signals are presented. There is obvious periodic characteristic, which can better characterize the fault, and can analyze the occurrence of bearing fault with the fixed period acoustic emission wave signal. The short time energy method is used to analyze the acoustic emission waveform flow signal of the rolling bearing, and the sound signal of the acoustic emission waveform flow collection is obvious at a high speed when the speed is high. The generation of rolling bearing fault is preliminarily judged by short time energy method. The spectrum analysis is used to analyze the wave signal and vibration signal of the acoustic emission of rolling bearings. The fault can be judged by the envelope spectrum analysis and power spectrum analysis, but the actual frequency of the rolling bearing can not be extracted because of the influence of the noise. The specific type of the fault can not be accurately judged. By using the bispectrum analysis combined with the envelope spectrum analysis, the acoustic emission waveform flow signal of the rolling bearing fault is analyzed and diagnosed. The peak frequency of different fault types in the running process of the rolling bearing is obtained by the bispectrum analysis three-dimensional graph, the contour map and the slice map, and the different fault solid of the rolling bearing is fixed. Good agreement between theoretical values with characteristic frequencies can be achieved for early diagnosis of different faults of rolling bearings.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH133.33
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本文编号：2110279