共查询到20条相似文献,搜索用时 140 毫秒
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介绍了抓斗卸船机电气传动的控制特点,分析了对早期投产的抓斗卸船机直流调速系统进行全数字直流调速系统升级改造或交流变频调速系统换型改造的优缺点。 相似文献
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国产WK-2、WK-4挖掘机电控系统现已更新,用新系统改造老产品费用高、周期长。本文介绍用单相桥式反并晶闸管整流电路供直流发电机励磁的调速系统,具有改造简单、价格低的优点。文章对晶闸管整流电路、移相触发电路、直流放大电路在电铲电气调速系统中应用作了介绍。 相似文献
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流溪河发电公司是一间老厂,由于设备老化,技术落后,需要对其进行升级改造,本文主要介绍了调速机、励磁系统、直流系统几个方面的改造,并介绍了改造中的关键技术和特点。 相似文献
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通过对龙门刨床电气系统改造设计方案的介绍,提出了采用PLC控制直流调速系统对老式龙门刨床K-F-D调速系统进行改造。这对改善系统静态、动态特性,降低能耗,增强设备加工能力发挥了非常重要的作用,具有较好的社会效益和经济效益。 相似文献
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主要介绍了采用英国欧陆公司生产的590P全数字直流调速装置和日本三菱PLC改造八米龙门刨床传动电控系统过程,通过对590P全数字直流调速装置部分功能巧妙置换使用,达到了解决低速切削速度不稳难题。 相似文献
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依据大功率直流PWM调速系统的迅猛发展,采用高性能的第三代智能功率模块IGBT和INTEI87C196MC微处理机对数控机床的主轴调速系统进行改造,设计了某大型数控机床主轴直流PWM调速系统。 相似文献
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张长水 《机械制造与自动化》2009,38(3):148-150
介绍宝钢股份南通钢铁有限公司全连轧改造自动控制系统的构成,该系统由加世纪80年代的日本东洋模拟调速系统、三菱PIE改造为Siemens数字直流调速系统6RA70,Siernem S7-400PLE,Simatic wincc6.0组态监控软件,实现了棒材轧制的自动控制.自投产以来,系统运行稳定. 相似文献
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The relations between the size of wear fragments and the sliding velocity or normal load were studied from a mechanical point of view for the unlubricated wear of nickel. It was found that the size of mean wear fragments has a definite quantitative correlation with the thickness of the plastically deformed substrate layer, irrespective of the experimental conditions. The thickness of the deformed layer is determined by the actual forces working on real contact points, which are dependent on the dynamic properties of the specific sliding system. These mechanical factors govern wear-velocity and wear-normal load characteristics. 相似文献
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贵阳特殊钢有限责任公司于2000年新建了一座60t Consteel交流电弧炉,该电弧炉具有国际先进水平,本文介绍了60t Consteel电弧炉除尘系统的工艺流程、特点及设计思路。 相似文献
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直线电机微进给机构的研究 总被引:4,自引:0,他引:4
微进给机构的频响和行程量对矛盾,介绍了一种高频响大行程的微进给机构,其关键部件为自行研制的直流直线电机,介绍直线电机的结构,给出了它的动力学模型,并对模型进行了分析和简化,在此基础上,进行 微查给机构闭环特生分析及控制器综合。性能实验结果表明,该微进给机构同时具有频响高、行程大和精度主的特点。 相似文献
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An original computer-controlled measurement system with electrodynamic sensor is presented in this paper. The system was used to examine simultaneously dependencies of time related electromagnet coil current, electromagnet coil voltage, electric power supplied to electromagnet coil, voltage across contacts, acceleration, speed, path and kinetic energy of contactor moving element. An additional software allows diagrams of the following parameters to be obtained: maximum and minimum acceleration, maximum speed and kinetic energy of contactor moving element, electric energy supplied to electromagnet coil and times typical of alternating current electromagnetic drive for selected values of the coil supply voltages and various switching on angles of this voltage (within the range 0–170°). Results of the investigation enable also to take a view on such parameters of the designed equipment as, for example, making time or rebounds of the contactor contacts. The system is very useful to verify the results of investigation of computer simulated contactor closing. 相似文献
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当风冷式空调机组的室外冷凝器的通风效果不畅的情况下,为了提高空调机组的运行效率,我们采用在室外机组上增加软化水喷淋辅助降温装置。并且该装置也可达到节能效果。 相似文献
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Charles E. Lyman 《Journal of microscopy》1995,178(3):286-287
Microstructural evolution in two in situ reinforced composite systems, one produced by partial reduction and the other by grain growth, has been examined over a range of size scales using light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Metal-ceramic matrix composites were formed by the partial reduction of Al2O3–Cr2O3 solid solutions to form Cr metal particles in an Al2O3–Cr2O3 matrix which had a lower Cr2O3 concentration. In a second system, grain growth of Si3N4 during liquid phase sintering produced large, whisker-like grains in a fine-grained Si3N4 matrix, bonded by an oxynitride phase. The mechanisms controlling microstructural evolution in these two systems were examined. 相似文献