查询词典 radius brick

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。

The radius is half of the diametre ,and the diametre is two times the radius.

半径是直径的一半，直径是半径的2倍。

Diamagnetic loop is new beam diagnostic technology, it measures electromagnetic parameter-magetic moment that is brought while beam is transforming, by measuring magnetic moment we can calculate beam radius. Diamagnetic loop is non-intrusive diagnostic system, it can diagnose beam radius on line and it can diagnose beam emittance and obliquity cooperating with other technology such as three gradient method and beam bugs.

反磁回路法是国际上近年来发展起来的一种新的束流诊断技术，它是通过测量束流传输过程中产生的电磁场参数对束流的特性——束流半径进行诊断的，是一种非阻挡型的诊断系统，可以在线诊断束流情况，与其它方法相配合还可以得出束流剖面的其它参数，具有结构简单、抗电磁干扰能力强、安装使用方便可靠等特点。

Theresults show that the electron mean drift velocity is affected by the cathode radius, theimpedance of the load diode, the inner radius of vanes and the input voltage.

结果表明电子平均漂移速度决定于阴极杆半径、负载二极管阻抗、阳极慢波叶片内径和输入电压。

Test and analysis show that, the distribution patterns of the tangent veloctiy fields in the big cone area and the small cone area, which are comprised of para-free vortex and para-forced vortex, are basically identical without a change of the radius of the boundary surface; with the increase of the angle of the small cone, the para-free vortex area decreases and the para-forced vortex area increases, and the emulsifiability of the fluid drips increases with the increase of velocity gradient; the tangent velocity increases with the increase of inlet flow, and the maximum tangent velocities of both the big cone area and the small cone area are 4.94 times of the inlet flow; and the maximum tangent velocity increases with the increase of the split ratio and with the radius of the boundary surface not changed.

试验分析表明，大锥段和小锥段切向速度分布规律基本相同，均由准自由涡和准强制涡构成，分界面半径rm没有变化；随着小锥角θ的增加，准自由涡区缩小，准强制涡区扩大，速度梯度增加会加大液滴的乳化程度；随入口流量增加，切向速度增大，经拟合得出大锥段和小锥段的最大切向速度均为入口流量的4.94倍；分流比加大，分界面半径基本不变，最大切向速度增加。

The equations of the curvature, curvature radius, main curvature and main curvature radius on hypocycloid抯 and epicycloid抯 theoretical tooth shape and practical tooth profile are deduced respectively.

根据微分几何知识，分别推导出内、外摆线理论齿形和实际齿廓的曲率、曲率半径、主曲率及主曲率半径的方程式，并绘制了内、外摆线理论齿形和实际齿廓曲线及理论齿形的曲率半径变化曲线。

Saturn's equatorial and polar radius of over 6,000 km radius difference.

土星的赤道半径和极半径相差6000多千米。

A fundamental parameter used in eclipse predictions is the Moon's radius k, expressed in units of Earth's equatorial radius.

日食预报的基本参数是月球半径K，其是由地球赤道半径来表示。

The WGS 84 Datum is generally accepted as the best simple mathematical model for the overall shape of the earth, and is an ellipsoid with an equatorial radius of 6378.1370 km and a polar radius of 6356.7523 km, and is centred on the earth's centre and orientated to the spin axis.

WGS 84基准﹙ WGS 84 Datum ﹚被普遍接受为地球整体形状之最简单数学模型，是一个赤道半径﹙ equatorial radius ﹚ 6378.1370公里和北极半径﹙ polar radius ﹚ 6356.7523公里之椭球﹙ ellipsoid ﹚，以地球的中心为中心点，并定位於﹙ orientated to ﹚自转轴﹙ spin axis ﹚。

The influence of the bark layer and trunk radial and height and the ratio of interior radius and exterior radius and ground elevation angle on scattering pattern is investigated.

第二，基于Monte-Carlo模拟技术，用相干叠加近似、树的独立散射近似和独立散射近似等方法，计算了倾斜或水平粗糙地面上分形树的电磁散射。

It also analyzes the feature and development of semi-finish grinding and finish grinding by roller press.

同时进行了辊压机半终粉磨和终粉磨系统的特点和发展分析。

When I got there, water was dripping slowly from the ceiling and forming a pool on the floor.

当我到那里的时候，水是慢慢地从天花板滴而且形成在地板上的一个池。