使磨损

The results are listed as following :㏕he best anti-erosion proportion of resin present is 25wt% in the condition of silicon carbide reinforced SMCC, while the alumina reinforced SMCC is 40wt%.(2) The better anti-erosion results was achieved with the ratio of silicone resin to acrylic resin containing hydroxy being 3: 1.㏕he composites coating tends to be more brittle when added in alundum particles. It also means that the maximum erosion peak of alundum reinforced SMCC tends to normal angle.甌he change of erosion rate of SMCC can be divided into two stages with the increment erodent velocity: the slow erosion stage of the beginning and the stable erosion stage.

首次发现：①SiC增强的复合涂料涂层，树脂含量为25wt％时，具有最佳耐冲蚀性能：Al_2O_3增强的复合涂料涂层，树脂含量为40wt％时，具有最佳耐冲蚀性能；②SiC增强的涂料，有机硅树脂与丙烯酸树脂的比例为3：1时的耐冲蚀性能好于1：1的复合涂料涂层；③Al_2O_3增强体使涂层变脆的倾向大于以SiC为增强体的涂层，即SiC增强的复合涂料涂层的最大冲蚀率出现在30°，Al_2O_3增强的复合涂料涂层的最大冲蚀率出现在75°～90°之间；④低速冲蚀磨损机理主要是弹性变形与疲劳；高速冲蚀磨损机理主要是显微切削和显微犁耕。

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。

Bloyce A, Dong H. Comparative evaluation of treatment for wear protection of Ti-6Al-5V. In:Proc 8th Word conf On Titanium, Birmingham, 19953 Fisher J, Dowson D. Tribology of total artificail jionts. Proc Instn Mech Engers, 1991; 205H:73

2化学镀Ni-P-PTFE复合层具有优异的耐磨性和减摩性，大大改善了Ti-6Al-4V摩擦磨损性能，使Ti-6Al-4V应用于在人工关节以及其它磨损较大的部位成为功效可能。

Head life expectancy is limited, and frequently will speed up the read-write head and head arm motor wear and tear and frequent disk read and write and even make the area a regional temperature, magnetic medium will affect the stability of the area will lead to read and write errors, due to high temperature will make the area of hot pockets of serious head and facial disc closer under normal circumstances head and disc surface only a few microns, have a closer?

磁头寿命是有限的，频繁的读写会加快磁头臂及磁头电机的磨损，频繁的读写磁盘某个区域更会使该区温度升高，将影响该区磁介质的稳定性还会导至读写错误，高温还会使该区因热膨涨而使磁头和碟面更近了（正常情况下磁头和碟面只有几个微米，更近还得了？

It is because of the mechanical behavior that the counter bearing pressure at the driving side of a mixing drum driven by a large-scale rubber tyre is not even and excessive ,which brings the elastic distortion to the tyre.

大型橡胶轮胎传动的圆筒混合机由于力学行为造成传动侧支反力不均且过大，使轮胎发生弹性变形，增大了弹性阻力矩，使电流波动过大，减速机经常磨损、胶合，导致轮胎磨损严重而停产。

Note 1. It may be helpful to test a vertical surface so that any loose abraded parti-cles fall away

注1：可以试验垂直面，使每一个磨损粒从侧面落下，而本身不会引起磨损。

Approaches of increasing wearability of materials under sand slurry wear condition were to reduce the micro-cutting of matrix structure and cut down the desquamating of carbide particles.

提出了在泥沙磨损条件下提高材料耐磨性的途径：一方面是如何减少基体组织的显微切削磨损；另一方面是如何使碳化物不易脱落，更好地起到保护基体的作用。

The Circulation-hydrogenation Compressor Model BLC-305/A is an important equipment with Hydrogenation devices, which is imported by Lanzhou Petrochemical Company Refinery. Due to high-speed rolling periodically, the spare parts of this compressor, to a varying extent, show a lot of signs of wear and tear. Especially, the axle sleeve of the rotor axle of the compressor is so worn to the greatest degree that its work efficiency decreases by a big margin. Machinery Factory of Lanzhou Petroleum Processing and Chemical Complex has undertaken this task to repair the rotor.

BCL—305/A型循环加氢压缩机是兰州石化炼油厂从国外引进的一台用于加氢装置的重要设备，该设备经长周期的高速运转，零部件均有不同程度的磨损，特别是压缩机转子轴上的轴套磨损程度最大，使整机效率大幅度下降，兰炼机械厂承担了这项转子修复任务。

Since the rotary plunger pump piston at each stroke can randomly rotate constantly change with the pump plunger cylinder contact surface, so that circular plunger gradually wear uniform or scaling at the same time, sand from the plunger and pump barrel between discharge and resolved accumulation Materials abrasion caused by wear and serious positioning rod release.

自旋转柱塞抽油泵可使柱塞在每一冲程中随机转动，不断地改变柱塞与泵筒的接触面，使柱塞圆周逐渐均匀磨损的同时将砂粒或结垢从柱塞与泵筒之间排出，解决了磨蚀材料聚集所引起的严重定位磨损及杆柱脱扣

With this method the copper plating graphite powder was made up in 50% copper content .The silver- copper plating graphite composite was prepared while the silver- copper-graphite composite and the silver-graphite composite were also made up together .The mechanical and electric characteristics of the three kinds of composites were tested and it was found that the copper plating graphite powder can only optimize the properties of the silver matrix composite under the high content of the graphite ,the conductivity and the mechanical property was improved and the material could take higher current in the same carbon content .At 20% carbon content, the resistivity of Ag-graphite composite was 1.67 times as high as that of silver- copper plating graphite composite, the resistivity of Ag-Cu-graphite composite was 3.23 times as high as that of silver- copper plating graphite composite. The bending strength of silver-copper plating graphite composite was 2.17 times as high as that of silver- copper-graphite composite, and the bending strength was 2.11 times as high as that of silver- copper-graphite composite. The wearability of silver- copper plating graphite composite was also enhanced greatly at high carbon content.

利用该方法制备了50%铜含量的镀铜石墨粉，然后进一步制备了一系列相同碳含量的银-石墨复合材料、银-铜-石墨复合材料、银-镀铜石墨复合材料，对三种材料的机械、电气性能进行了综合对比，发现在低碳含量时镀铜石墨粉不能改善复合材料的上述主要性能，而在中高碳含量时则能明显优化复合材料的整体性能，提高了复合材料的电导率，使复合材料在中高碳含量时既具有较高的耐磨性同时也能负载较大的电流，复合材料的机械性能也因镀铜石墨粉的加入而大幅提高，20%碳含量时，银-石墨复合材料的电阻率是银-镀铜石墨复合材料的1.67倍，银-铜-石墨复合材料的电阻率为银-镀铜石墨复合材料的3.23倍，银-镀铜石墨复合材料抗弯强度是银-铜-石墨复合材料的2.17倍，是银-石墨复合材料的2.11倍，同时，在实验给定的条件下，中高碳含量时银-镀铜石墨复合材料的机械磨损耐磨性和通电磨损耐磨性都得以显著提高，银-镀铜石墨复合材料在实验时的接触电压降也更为稳定。

Objective: To study the effect of polycythemia on blood oxygen saturation.

裴蕾目的：观察RBC剧增而引起的高粘血症对血氧饱和度的影响。

Based on SIMPLER algorithm in the curvilinear body-fitted coordinates, the calculations were performed for Pr=0.7, Re=10~1000 on non-orthogonal non-staggered grids which are generated by elliptic equation systems.

采用曲线坐标系下压力与速度耦合的SIMPLER算法，数值研究了周期性渐扩渐缩波纹通道内脉动流动与换热情况，流动Re数的范围为10~1000，Pr数为0.7。