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The effect of tribology factors on bearing vibration is studied experimentally. AR model and WPT are used to processing the normal arid abnormal signals. The results are as follows:1. The vibration of ball bearings is caused by the tribology action of contact pairs of ball and ring races and has the essential of tribo-dynamics. Any factors affecting the tribology characteristics of contact pairs will affect vibration and noise of bearings consequently.2. Vibration characteristics of bearing keep almostly unchanged with the increasing of axial load expecting the increasing of nature frequencies. When radial load increasing with axial load unchanged, nature frequencies keep unchanged but some new vibration peaks appears in the spectrum.3. Vibration amplitudes are damped and nature frequency are enhanced with sufficient lubrication. Vibration and noise of bearings increase obviously and roar can happen and the contact surfaces scratch slightly under insufficient and unclean lubrication state. Bearing will be disabled in a few minutes without any lubrication.4. Bearing vibration is unstable under low speed. With the speed increasing, the vibration become stable and natural frequencies increase slightly but the amplitudes increase apparently.5. Bearing vibration can be excited only by some harmonics ofwaviness without lubrication and by all harmonics with lubrication based on the theoretical analysis.6. The nature frequencies of ball bearings decrease with the increasing sizes. When international clearance increasing, nature frequencies decrease in radial and increase in axial and angular and the amplitudes increase in radial and decrease in axial and angular. When the number of balls increasing, nature frequencies increase and amplitudes decrease. When the pitch diameter increasing, axial nature frequency increase and others nearly keep no change. When outer race groove curvature radius increasing, nature frequencies increase in radial and decrease in axial and angular and amplitudes keep no change in radial and increase in axial and angular. When inner race groove curvature radius increasing, nature frequencies decrease and amplitudes increase.7. The distortion in amplitude and frequency components of bearing vibration signals picked up by the present probe measurement method is founded and right conclusions cannot be achieved by the signals. When accelerometer is rigidly screwed with steel stud onto a flat outer surface of a ball bearing, vibration signal can be got without distortion and the reliability of research on bearing vibration is assured.8. AR model is suitable for large samples of bearing vibration signals, square root of length of samples can be used as the upper limitation of order determination and the FPE order selection criterion is effective. Many advantages of AR spectrum are founded over the classical based on FFT.9. Time-Frequency analysis is necessary for abnormal noise of ball bearings. WPT overcomes the principle shortcomings of STFT and proved to be a best tool to process the abnormal signals.

理论分析和试验研究表明： 1球轴承振动是钢球—滚道接触副中的各种摩擦学作用引起的，具有摩擦动力学的本质，任何对接触副的摩擦学特性有影响的因素都将对球轴承的振动和噪声特性产生影响； 2中心轴向载荷作用下，载荷增大使球轴承的固有振动频率升高，载荷越大同样的载荷增幅引起的频率升幅减小，足够大的中心轴向载荷作用下载荷的变化对球轴承振动的频率特性不会产生明显的影响； 3轴向和径向联合载荷作用下，径向载荷不大时球轴承振动的固有频率基本不变，但是可能引起变刚度激励的非线性振动，出现新的频峰，过大的径向载荷将使部分钢球脱离接触，使球轴承的振动和噪声呈现不稳定状态； 4润滑对球轴承的振动和噪声特性有重要的影响，良好的润滑对振动有明显的抑制作用，润滑不充分时，振动和噪声的水平会有明显增高，一定条件下还会激发接触副中的谐振，发出啸声，造成接触表面的伤害，无润滑干接触时，短时的运转就会损伤接触副表面，使振动和噪声迅速增大，并随时可能引发严重的磨损和卡滞失效；接触副润滑良好时，油膜的"刚化效应"使球轴承振动的固有频率有所提高，润滑剂中含有弥散性污浊时，振动的幅度总体升高，但弥散性污浊不会改变球轴承振动的频率特性；浙江大学博士学位论文：球轴承振动的研究 5低速时，球轴承振动的基本特征呈现不稳定状态，随着转速的提高，球轴承振动的频率特性趋于稳定，固有频率频峰升高； 6理论分析表明，干接触时钢球和滚道表面波纹度的某些谐波分量能激励球轴承的振动，振动的幅值与谐波幅值成正比，实际球轴承中钢球的分布不可能完全均匀，波纹度的激励作用会随时发生；润滑接触的分析表明，波纹度的任意谐波分量均能激励球轴承的振动； 7球轴承的几何和结构参数分析表明，球轴承尺寸越大，径向、轴向和角振动的固有频率越低；钢球中心圆直径增大，球轴承的径向和轴向振动的固有频率基本不变，角振动的固有频率有所上升，振动的幅频特性基本不变；径向游隙加大使球轴承的径向振动固有频率降低，轴向和角振动的固有频率有所升高，径向振动幅频特性的幅值升高，而轴向和角向降低；钢球的数量增多使球轴承振动的固有频率上升，幅频特性的幅值下降，径向振动的幅值下降最为明显；外圈沟曲率半径系数增大使球轴承径向振动的固有频率升高，轴向和角振动的固有频率降低，径向幅频特性基本不变，轴向和角向幅频特性幅值升高；内圈沟曲率半径系数增大使径向、轴向和角振动固有频率均下降，振动幅频特性的幅值均有升高； 8试验对比表明，传感器采用探针式安装时，由于探针接触副接触特性的影响，钡(量得到的球轴承振动信号有失真，采用专门设计和制作的试验球轴承，以固定式安装加速度计，首次测量得到了球轴承振动的真实信号，通过对振动信号的分析，验证了球轴承振动的理论模型； 9)基于时间序列分析的AR模型适用于大样本球轴承振动信号的分析，以样本长度的均方根值作定阶上界，FPE做判阶准则，给出的AR谱光滑，频率分辨率高，是球轴承振动分析的简便而可靠的手段； 10以时频域分析的小波包变换分析球轴承异音信号能够比较好地定位和聚焦异音发生的时间，时间间隔，频率范围，同样是球轴承振动分析的可靠的手段，可用作球轴承故障诊断技术。

Firstly, electrization knowledge related to the research is introduced. After a deep study on various contact loss detection techniques, especially on the electric arcs detection techniques, we draw the conclusion that the untouched detection technique based on phototube sensor can acquire exact contact loss information, and will to be the leading technique for contact loss measurement in future. Secondly, combining with the special railways system in our country, we analyze the cause of the arcs, and the influence on the power supply system and the on board traction drive due to the arcs in detail, and study the arcs' spectrum characteristic. We also analyze detecting principles and put forward with a method - using phototube sensor to detect the contact loss arcs, conceive the configurations and detection flows of the measurement.

文章通过对电气化铁道相关知识的了解及对国内外离线检测技术的深入了解，尤其是对离线电弧检测技术的了解，总结出了基于光电传感器的非接触离线电弧检测系统能够得到准确的弓网离线情况，并且是国内外检测技术的发展方向；文章详细的分析了离线电弧产生的原因，电弧对机车牵引动力的影响情况，研究了我国铁路系统中离线电弧的光谱特征分布；分析了系统的检测原理，提出了采用光电传感器实现对离线电弧进行检测的方法，并设计了"电力机车弓网离线电弧检测装置"的检测功能和管理功能，规划了系统的组成结构及检测流程。

Outgoing and friendly, as a working pack breed, Harriers must be able to work in close contact with other hounds.

外向而友善，象所有的群猎犬一样，哈利犬工作时，必须能与其他猎犬密切配合。

Nn Temperament nOutgoing and friendly, as a working pack breed, Harriers must be able to work in close contact with other hounds.

n外向而友善，象所有的群猎犬一样，哈利犬工作时，必须能与其他猎犬密切配合。

She is divided into M-shaped legs, pulling me in her soft body Without bones, I am impulsive waves, the stem hard to push her to the Department of the private, this is my first time, stem the first time contact with the woman's genitals,like imaginary dreamlike feeling and can not be implicit.

她把双腿分成M形，把我拉在她的柔若无骨的身上，我一阵阵冲动，把硬梆梆的茎向她的私部推去，这是我的第一次，茎第一次与女人的阴部接触，那种感觉如梦如幻，一时难以言明。

The post holder will be in regular contact with external companies and customers, and must present SECCO's value

本职位人员将经常与外部公司与客户联系，因此必须向外界体现赛科的价值及名誉

For example, a clerk may be time in a week contact with hundreds client.

例如，一个服务员在一星期里可能定时与数百位顾客联系。

Before in the reseau computer of bring into contact with, basically be calculate like a matrix node structure, use the operating system of kind of UNIX, and the communication between computational node, often need specific consultative implementation.

在以前接触到的网格计算机中，基本上是一个矩阵似的计算节点结构，使用类UNIX的操作系统，而计算节点之间的通信，往往需要特定的协议实现。

Respirators used in close contact with a known or suspected SARS patient must be disposed of immediately after use.

对在密切接触已知的或怀疑的SARS患者时所佩戴的防护口罩，必须在使用后立即将之废弃。

Can't contact with Arkadiy, he should be waiting for me in Tallinn.

没联络到Arkadiy，他应该会在塔林等我吧。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。