强冲击下变速箱滚动轴承故障特征提取及状态评估研究

发布时间：2018-03-21 14:07

本文选题：强冲击　切入点：变速箱　出处：《中南大学》2014年硕士论文　论文类型：学位论文

【摘要】：摘要：针对装甲车在运行过程中负载大、冲击强、故障特征不易提取的特点,本文采用负载突变模拟强冲击,对滚动轴承的滚动体磨损、外圈裂纹及内外圈间隙增大这三种故障类型,采用动力学仿真及实验分析了强冲击下变速箱信号特征,分别从时频特征提取及状态评估两个方面,实现了强冲击下变速箱滚动轴承不同故障类型的故障诊断。论文主要研究内容包括： (1)对滚动轴承结构、振动机理及失效方式进行分析,确定本文研究的故障类型及意义。采用动力学仿真分析了滚动轴承不同故障状态下碰撞力及轴心轨迹等动态特性,以及不同形状负载冲击模拟,选择最佳冲击方式,进行了强冲击下不同间隙故障的动态特性分析。 (2)研究了时域统计特征量随转速、平稳负载及冲击负载的变化规律；分析了不同间隙故障在强冲击工况与平稳工况下熵值,说明强冲击工况的建模有效；提出了能够明显表征强冲击下轴承间隙磨损程度的特征量—峰值因子。 (3)针对强冲击下滚动体磨损及外圈裂纹的故障类型,提出了小波变换、能量分析与包络谱分析相结合的方法,提取振动加速度信号进行包络谱分析,提取了故障特征频率,实现了强冲击下变速箱滚动轴承滚动体磨损及外圈裂纹故障的特征提取。 (4)针对强冲击下滚动轴承不同间隙故障,提出了小波变换与模糊聚类相结合的方法,判别出未知信号的故障状态,从而实现了强冲击下滚动轴承间隙磨损程度的状态评估。
[Abstract]:Absrtact: in view of the characteristics of heavy load, strong impact and difficult to extract the fault features of armored vehicle during operation, this paper uses load mutation to simulate strong impact and wear rolling body of rolling bearing. There are three kinds of fault types: outer ring crack and outer ring gap increase. Dynamic simulation and experiment are used to analyze the signal characteristics of gearbox under strong impact. The characteristics of transmission signal are extracted from time-frequency feature extraction and state evaluation, respectively. The fault diagnosis of different fault types of gearbox rolling bearing under strong impact is realized. The main contents of this thesis are as follows:. 1) the structure, vibration mechanism and failure mode of rolling bearings are analyzed, and the types and significance of the faults studied in this paper are determined. Dynamic simulation is used to analyze the dynamic characteristics of the rolling bearings under different fault conditions, such as the collision force and the orbit of the shaft center. The dynamic characteristics of different clearance faults under strong impact are analyzed by selecting the best impact mode and simulating the load with different shapes. (2) the variation law of time-domain statistical characteristic with rotational speed, stationary load and impact load is studied, and the entropy value of different gap faults under strong impact condition and stationary condition is analyzed, which shows that the modeling of strong impact condition is effective. The peak factor, which can clearly characterize the wear degree of bearing clearance under strong impact, is proposed. 3) aiming at the fault types of rolling body wear and outer ring crack under strong impact, a method combining wavelet transform, energy analysis and envelope spectrum analysis is proposed to extract the vibration acceleration signal for envelope spectrum analysis and to extract the fault characteristic frequency. The feature extraction of rolling body wear and outer ring crack fault of gearbox rolling bearing under strong impact is realized. In view of the different clearance faults of rolling bearing under strong impact, a method of combining wavelet transform and fuzzy clustering is proposed to distinguish the fault state of unknown signal, thus realizing the state evaluation of the wear degree of rolling bearing clearance under strong impact.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TH165.3

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