定位圆

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。

Methods The effects of the reading error and the misalignment of the probes on the accuracy of measuring and all the harmonics of roundness were analyzed; The strategy and the algorithm for optimizing the parameters of the measuring system were proposed; The distribution and propagation patterns of the measured errors for all the harmonics of roundness were studied in detail; A software for correcting the errors caused by the measurement error of the angle positions of the probes and the sensitivity difference between three probes was presented.

分析了测头读数及角位置误差对圆度各次谐波及圆周各点测量精度的影响；提出了三点法测量系统的优化策略与算法；研究了三点法测量误差的分布与传递规律；提出了克服测头定位误差以及3个测头的灵敏度不一致影响的软件校正方法。

In one mission flight, the Global hawk can proceed extension area radar search and EO/IR photo capturing for 74,000 square kilometers, the minium CEP of the target positioning would be 20 meters.

一次任务飞行中，"全球鹰"既可进行大范围雷达搜索，又可提供7.4万平方千米范围内的光电/红外图像，目标定位的圆误差概率最小可达20米。

In one embodiment, the arc shaped blades are positioned rearwardly with respect to the distal section of the obturator.

在一个体现，圆弧形的刀片定位rearwardly方面的闭孔远端部分。

The driver consists of magnetostrictive rod, front magnetic pole end cap, back magnetic pole end cap, exciting winding, micro displacement output head, casing, fixed end cap, front end cap, spring, winding tap, flat spiral pipe, water inlet pipe and water outlet pipe. The water cooler of the present invention is formed through inserting one end of some metal pipe into positioning hole of spindle, installing rolling tool onto tool carrier, adjusting the lathe to the pitch of the flat spiral pipe and starting the lathe to complete the extruding formation of the flat spiral pipe.

本发明的驱动器包括有磁致伸缩棒(7)，前磁极端盖(3)，后磁极端盖(10)，励磁线圈(5)，微位移输出头(1)，壳体(12)，固定端盖(9)、前端盖(2)，弹簧(13)，及线圈抽头(11)，螺旋扁管(6)，入水管(8)和出水管(4)；本发明的水冷装置的成型方法为把金属圆管的一端插入芯轴(18)的定位孔(23)中，将滚压工具(20)安装在刀架上，调整车床的加工螺距与螺旋扁管(6)的螺距相等，启动车床，完成整个螺旋扁管的挤压成型。

The export variant of the P-12 short-range ballistic missile is armed with a medium-stage global positioning system guidance device and has a circular error probable, or CEP, of 50 meters (164 feet).

出口的变体为P -12短程弹道导弹是武装起来的一个中等阶段，全球卫星定位系统制导设备，并有一个圆概率误差，或临选， 50米（ 164英尺）。

The algorithm for optimizing the parameters of the measuring system were proposed; The distribution and propagation patterns of the measured errors for all the harmonics of roundness were studied in detail; A software for correcting the errors caused by the measurement error of the angle positions of the probes and the sensitivity difference between three probes was presented.

分析了测头读数及角位置误差对圆度各次谐波及圆周各点测量精度的影响；提出了三点法测量系统的优化策略与算法；研究了三点法测量误差的分布与传递规律；提出了克服测头定位误差以及3个测头的灵敏度不一致影响的软件校正方法。

The company specially has the superiority in the US standard screw and each kind of high difficulty non- sign aspect, moreover may provide each kind of material quality product according to the customer request, the concrete item includes: Outside US standard in hexagonal screw, US standard hexagonal screw, US standard horse-drawn vehicle screw, US standard set screw, US standard pan head screw, US standard flat screw, US standard studs screw, US standard threaded rods, US standard eye bolts screw, US standard welding screw, US standard T screw, US standard square head screw, suspension loop screw, US standard hexagon nuts, US standard flange nut, US standard nylon nut, US standard hexagon machine nut, US standard cover nut, US standard butterfly nut, US standard square nut, US standard round nut, US standard suspension loop nut, US standard ball pad, US standard flat washers and so on US standard fastener and each kind of high difficulty non- sign design.

公司特别在美制螺丝及各种高难度非标方面具有优势，而且可以根据客户要求提供各种材质产品，具体品项包括：美制外六角螺丝、美制内六角螺丝、美制马车螺丝、美制紧定螺丝、美制盘头螺丝、美制十字槽盘头螺丝、美制平头螺丝、美制双头螺丝、美制牙条、美制活节螺丝、美制焊接螺丝、美制T型螺丝、美制地脚螺丝、美制碟型螺丝、美制鞋子定位螺丝、美制方头螺丝、美制吊环螺丝、美制六角螺母、美制法兰螺母、美制尼龙螺母/美制自锁螺母、美制尼龙盖帽螺母、美制六角机螺母、美制六角薄螺母、美制浮动螺母、美制盖型螺母、美制六角嵌入式螺母，美制K帽，美制蝶型螺母、美制方螺母、美制圆螺母、美制压铆螺母，美制吊环螺母、美制不锈钢开口销、美制弹垫、美制平垫等美制紧固件及各种高难度非标设计。

Methods The sensory root of semilunar ganglion of trigeminal nerve in the foramen ovale was punctured by needle, which connected with electrode of radiofrequency thermocoagulation instrument.

用穿刺针经前路法穿刺，到达卵圆孔内三叉神经半月节感觉根，连接射频温控热凝仪及相配套电极，先进行方波定位刺激，确认无误后，一次性快速加热至 88℃左右，在感觉根的 2～ 3个断面上热凝。

The radius of the punch and die cutting edges is laid out to produce the desired circular shape without nicking into the circle as the work proceeds.

在工作过程中，冲头与凹模切口的半径定位，确保形成所需的圆形，而不至于在圆边产生&缺口&。

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。