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镜板变形是推力轴承理论计算中涉及到的主要变形之一。三维热弹流计算可以给出镜板表面温度场,从而可计算镜板表面热变形。本文给出弹簧束支承推力轴承镜板表面变形的试验结果及计算结果。 相似文献
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因一些条件的共同存在.使某水轮发电机推力轴承的镜板带电,而且电压不断升高造成放电。在放电瞬间引起上导油盆盖与大轴间的间隙放电和推力轴承座瞬间带电.而轴承座带电又造成推力瓦测温装置烧损。鉴此,分析了镜板放电引起上导油盆盖与大轴间隙处放电及轴承座瞬间带电的原理.并阐述了故障的处理方法。 相似文献
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本文阐述水轮发电机组液压支柱式推力轴承受力调整方法,即在水-发联轴处于自由状态下对转轮上下止漏环、空气间隙、镜板水平的调整.保证转轮上下止漏环、空气间隙和镜板水平的设计数据,能缩短液压支柱式推力轴承受力调整的时间,提升工作效率和质量. 相似文献
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现代大中型、巨型水轮发电机组的总推力负荷最高达41MN 左右,推力瓦的压力高达4.9~6.86MPa,镜板的平均圆周速度高达10多米每秒(葛州坝水电厂大机镜板的平均圆周速度为9.87m/s),推力轴承功耗高达300~400kW,这些损耗转变为大量的热能,因此就要求有良好的推力轴承润滑冷却系统,以确保推力轴承能维持在规定的温度下(一般在50~65℃)运行。 相似文献
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分析了三峡电站ALSTOM机组推力轴承产生推力头镜板结合面锈蚀,结合螺杆断裂问题的原因为镜板厚度不足,以及结合螺杆规格过小,螺杆弦距过大等问题。提出了在现有结构上增加螺杆数量,镜板推力头结合面内外圆处加工密封槽,并设置密封圈的基本思路。该方案实施后,所有改造轴承目前运行良好。 相似文献
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<正>三峡右岸的镜板尺寸现改为Φ5220mm×82mm,镜板厚度比原尺寸更薄。为克服镜板自身柔性产生的变形,需采取镜板与推力头把合成整体的加工方案。研磨装置经改造后可用于三峡右岸镜板。要保证推力头镜板的把合面之间没有间隙,且镜板最后超精加工也要选择一个合理的加工余量。经过反复研究和试验,最终确定镜板单件加工留加工余量,为下一步超精加工研磨打下基础。 相似文献
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Mathematical Modeling and Analysis of MEMS Deformable Mirror Actuated by Electrostatic Piston Array
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AKIKO UNO YOSHIKAZU HIRAI TOSHIYUKI TSUCHIYA OSAMU TABATA 《Electrical Engineering in Japan》2018,204(2):50-60
In this report, we constructed a simple mathematical analysis model for a new MEMS deformable mirror using an electrostatic piston array. The deformable mirror has been developed as a wavefront compensation device in adaptive optics for retinal observation. The device realizes a large convex deformation with a low operation voltage because of moving bottom electrodes on the pistons. The constructed model is based on the plate theory and simple superposition of the actuation components. The calculated deformation analyzed using this model agrees well with that analyzed using the finite element method not only in deformation shape but the peak‐valley deformations. In addition, the calculation time is much shorter, so the model can be used for design optimization of the device. 相似文献
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Ahmed M. Soliman Ramy A. Saad 《International Journal of Circuit Theory and Applications》2010,38(8):787-795
The voltage mirror–current mirror (VM–CM) pair is shown to be a universal active element. It provides two alternative realizations for the nullor. The VM–CM pair is also capable of realizing the op amp and all the four types of the current conveyors namely CCII?, CCII+, ICCII? and ICCII+ as special cases. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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拉西瓦水电站总装机容量为6台700MW水轮发电机,机组自2008年5月首台投入并网使用至今,一直发挥着巨大的作用,在例行检修时发现2F、5F机组推力瓦和镜板出现非正常磨损,通过检修时目击的现象及结合现场实际情况,从整个推力系统入手,综合分析了产生这一现象的本质原因,并结合电站检修时间、工具等方面限制的实际情况,采取现场处理镜板、调整喷油管、调用备用推力瓦等工艺方案,圆满的解决了问题,为巨型机组推力轴承系统现场处理积累了经验。 相似文献
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Hung‐Yu Wang Yuan‐Long Jeang Ying‐Chuan Liu Yu‐Wei Huang 《International Journal of Circuit Theory and Applications》2010,38(7):761-769
A novel CMOS cascode current mirror configuration with enhanced input dynamic range is presented. The proposed mirror circuit combines the advantages of wide input swing, wide output swing and large output resistance capability, which make it attractive for practical application. Based on 0.18 µm MOS model parameters, HSPICE simulation results show that the input current ranges from 1 µA to 1 mA with large bandwidth for the proposed circuit. The simulation results confirm the theoretical prediction. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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Shinji Shinnaka 《Electrical Engineering in Japan》2002,139(2):61-71
In this paper, a mathematical model of the synchronous reluctance motor in a new form is established, followed by a new analysis of stator linkage flux of the motor, which characterizes the motor and plays an essential role in developing new rotor salient‐pole orientation methods for sensorless vector controls. Finally in a unified manner based on the inherent characteristics of the flux, six new potential salient‐pole orientation methods are developed and proposed. © 2002 Scripta Technica, Electr Eng Jpn, 139(2): 61–71, 2002;DOI 10.1002/eej.1153 相似文献
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采用镜像原理对 2相同导体球之间的电容进行了分析 ,并推出 2个不同的计算公式。通过实例 ,对 2种计算方法进行了比较分析 相似文献
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