HXD1B型电力机车4QC运用故障分析

HXD1B型电力机车是大功率交流传动六轴干线货运用电力机车。武汉铁路局江岸机务段自运用HXD1B型电力机车以来,四象限整流器(4QC)故障成为引起机破和临修的重要原因,有必要对4QC运用中出现的故障进行分析,并提出处理方案。     

北车集团自主设计9600kW电力机车

日前，以北车集团大连机辆公司为主、自主研发生产的六轴9600kW货运电力机车完成了两台样车试制，应用的多项自主创新设计取得了突破。     

快捷货运电力机车与货车供电匹配技术方案研究

快捷货运电力机车依托时速160公里快速客运电力机车产品平台,从快捷货运列车的需求出发,对机车与货运车辆间的电能供给开展了机车与货车的一体化匹配技术研究,并提出了设计方案。     

中国北车集团大同电力机车有限责任公司

由同车公司引进消化吸收国际先进技术生产的180台和谐2型八轴大功率电力机车，已全部配属于我国最繁忙的重载铁路——大秦线，成为重载货运的主力车型；同时，同车公司己搭建起具有世界先进水平的六轴大功率机车技术创新平台，将为铁道部提供500台和谐2B型电力机车。     

中国铁路的“超级大力士”

新一代和谐型大功率电力机车是我国自主研制轴重最大的电力机车产品,标志着我国在大轴重货运机车及铁路重载运输方面取得重大突破。     

精细化工艺设计，提高中自货运1型机车竞争力

中白货运1型机车是中国北车集团大同电力机车有限责任公司在白俄罗斯国际招标采购中标的大功率干线货运机车项目。该项目于2010年3月23日由大同电力机车有限责任公司与中国电气进出口有限公司、白俄罗斯铁路联盟在明斯克共同签署了《中白货运1型机车供货合同》。该型机车基于HXD2机车技术平台进行设计，应用HXD2系列机车的成熟技术和结构，进行大量适应性设计，以满足白俄罗斯宽轨铁路和机车车辆标准体系的相关要求。     

HX_D1B型交流传动货运电力机车牵引齿轮修形计算分析

针对HXD1B型交流传动货运电力机车驱动装置结构,指出了影响小齿轮轴修形的各种因素,并通过对各种因素建模分析,得出了小齿轮轴的综合修形量。     

曼罗兰印刷机主传动修理一例

用一台国产电磁调速异步电动机及一台六极异步电动机,通过传动机构的适当改动,代替进口三 相异步整流子式变速电机,对进口印刷机主传动系统进行修理,效果理想,达到了节约资金和缩短维修周 期的目的。     

非概率法的钢轨可靠性分析

基于Hertz接触理论,以大秦重载铁路钢轨为研究对象,将HXD1型交流传动货运电力机车车轮和钢轨的曲率半径、材料弹性模量、泊松比及机车单轮重量和轮轨运行冲角等不定参量设为区间变量,运用非概率法进行强度可靠性分析。计算结果表明,HXD1型交流传动货运电力机车在大秦重载铁路钢轨上运行过程中,其钢轨强度可靠性满足使用要求,证明了非概率可靠度算法在钢轨强度可靠性研究中应用的可行性,为今后钢轨可靠性的研究提供了一种简单有效的方法。     

引进大功率电力机车牵引齿轮对于热处理工艺与装备的要求

法国阿尔斯通大功率交流传动货运电力机车HXD2为铁道部技术引进机车项目。HXD2牵引主、从动齿轮使用寿命要求不得低于100万km。     

平面六杆机构误差分析

把六杆机构分解成初级四杆机构和次级四杆机构,再根据平面四杆机构的分析方法,逐步对六杆机构的误差进行分析,从而根据机构位置精度的要求来制订构件的制造公差.     

装载机连杆机构运动干涉问题的研究

以装载机反转六杆机构为例,对由于连杆机构的结构尺寸设计不合理而使动臂在举升和在上限位置卸料过程中,易造成铲斗四连杆机构ABCD发生干涉的问题进行了分析,得出了不发生干涉的若干条件。     

恒流源偏置三相磁悬浮轴承研究

六极结构恒流源偏置磁悬浮轴承是一种新颖结构,在定子磁极上有两套绕组,分别形成两对极偏置磁场与一对极控制磁场,根据无轴承电机原理,可产生可控悬浮力。笔者先采用等效磁路法,推导出该轴承在平衡位置附近的线性模型,并用有限元法进行了验证,对两个自由度上电流与位移之间的耦合进行分析,得到按矢量变换方式控制时,耦合较小的结论。然后,设计了一台实验样机,利用TI公司的VC33控制芯片,实现了两自由度静态悬浮,并对偏置磁场对悬浮性能的影响做了比较。最后,进行了动态激振实验。结果表明:三相磁悬浮轴承动态性能良好,适用于高速应用场合。     

Immunohistochemical distribution of enkephalin, substance P, and somatostatin in the brainstem of the leopard frog, Rana pipiens

The brainstems of frogs contain many of the neurochemicals that are found in mammals. However, the clustering of nuclei near the ventricles makes it difficult to distinguish individual cell groups. We addressed this problem by combining immunohistochemistry with tract tracing and an analysis of cell morphology to localize neuropeptides within the brainstem of Rana pipiens. We injected a retrograde tracer, Fluoro-Gold, into the spinal cord, and, in the same frog, processed adjacent sections for immunohistochemical location of antibodies to the neuropeptides enkephalin (ENK), substance P (SP), and somatostatin (SOM). SOM+ cells were more widespread than cells containing immunoreactivity (ir) to the other substances. Most reticular nuclei in frog brainstem contained ir to at least one of these chemicals. Cells with SOM ir were found in nucleus (n.) reticularis pontis oralis, n. reticularis magnocellularis, n. reticularis paragigantocellularis, n. reticularis dorsalis, the optic tectum, n. interpeduncularis, and n. solitarius. ENK-containing cell bodies were found in n. reticularis pontis oralis, n. reticularis dorsalis, the nucleus of the solitary tract, and the tectum. The midbrain contained most of the SP+ cells. Six nonreticular nuclei (griseum centrale rhombencephali, n. isthmi, n. profundus mesencephali, n. interpeduncularis, torus semicircularis laminaris, and the tectum) contained ir to one or more of the substances but did not project to the spinal cord. The descending tract of V, and the rubrospinal, reticulospinal, and solitary tracts contained all three peptides as did the n. profundus mesencephali, n. isthmi, and specific tectal layers. Because the distribution of neurochemicals within the frog brainstem is similar to that of amniotes, our results emphasize the large amount of conservation of structure, biochemistry, and possibly function that has occurred in the brainstem, and especially in the phylogenetically old reticular formation.     

汽车B柱Rollforming成型的有限元仿真

在汽车车体构件制造中的辊弯成型工艺应用项目研究中,利用大型非线性有限元分析软件MSC.Marc研究了汽车B柱变截面辊弯成型仿真的有限元建模方法,主要包括板料模型和成型辊模型的建立、单元选择、边界条件、各种参数的设置及成型辊的速度加载等内容,然后采用刚性轧辊沿板料长度方向平动的方式对板料成型过程进行仿真模拟,分析了板料在...     

APPLICATION OF WAVELET TRANSFORM ON DIAGNOSIS AND PREDICTION OF MILLING CHATTER

In order to avoid the accuracy deterioration or tool damage caused by milling chatter, it is necessary to have an efficient and reliable diagnosis system that can on-line predict/detect the occur-rence of chatter. The diagnosis/predicting system proposed is to on-line process and analysis the vi-bration signals of the milling machine measured by accelerometers. According to the analysis results, the system will be able to detect/predict the occurrence of the chatter. The diagnosis algorithm is, first, collecting both the normal signals and chatter signals from milling processes, and then, converting the signals through wavelet transform and fast Fourier transform (FFT). Since the converted chatter sig-nals exhibit different characteristics from the normal signals, through defining the characteristic val-ues, such as root-mean-square value, max value, and ratio of peak value to root-mean-square value, etc, a diagnosis reference library that contains the distribution of these characteristic values is built for diagnosis. When a diagnosis is executing, the characteristic value of the measured signals is con-trasted with the diagnosis reference. The approach index which shows the possibility of occurrence of milling chatter will, then, be calculated through the diagnosis system. Cutting experiments are con-ducted to verify the proposed diagnosis system. The results show the success of early chatter detecting for the system.     

简易多功能计数器的设计

设计了一个简易多功能计数器,由89C52单片机控制。配合相应的测量电路以及相应的软件,实现对频率、周期和时间间隔,被测信号峰值、温度等的测量,可记录10个历史数据,且具有掉电保持功能。其主要电路包括电平电路、时基电路、测频电路、测周电路、测温电路,键盘输入电路,显示电路等,信号输入后先自动判断频率的范围,然后选择需要的测量电路.通过单片机对数据进行处理,在误差允许的范围内显示各个测量值。     

“老板文化”对“企业文化”的作用——也谈“企业文化”建设的认知

优秀企业的成长、发展、壮大,与其优秀的＂企业文化＂建设不无关系。任何企业都是有文化的,不存在没有文化的组织,只有不同文化的组织。衡量企业文化的标准,只有显著程度、优劣和现实性,而不是有或无。只要有人群存在,他们的行为就构成一定的文化。企业老板,是企业文化的倡导者和缔造者。老板对企业文化建设的影响很大。＂老板文化＂是＂企业文化＂的奠基石。因此,企业要创建优秀的企业文化,企业领导层首先要有优秀的＂老板文化＂。而随着企业的发展,企业所有员工共同参与讨论并提炼企业文化,逐步走向民主与开放。这时的企业文化更多的融入了集体的智慧,老板文化的作用会逐渐减小,所以企业文化又不单是老板文化。     

浅谈汽油机尾气排放的控制

汽油发动机尾气排放控制主要分为机体内的控制和机体外的控制;关于机体外的控制,笔者从废弃再循环装置、二次空气供给系统、曲轴箱通风、燃油蒸发控制、三元转化催化装置等五个方面进行了阐述,并得出的结论是汽油发动机的尾气控制是综合控制,与多方因素有关.     

A system for wear prediction in lubricated sliding contacts

A system of analysis is developed to predict the rate of wear in sliding contacts. The essence of the approach is the proposal that the rate of wear can be predicted only in probabilistic terms. Therefore, the estimation of the probability of wear, which can be regarded as synonymous with the probability of surface asperity contacts, precedes the calculation of the wear rate. Further, recognising the fact that wear takes place within the actual area of contact, it is argued that this area consists of plastic and elastic contacts between asperities which, in turn, have different shear strengths and contribute differently to the wear process. In the case of lubricated contact, a frictional film defect represents the influence of a lubricant on the wear process. Moreover, as in this type of contact the load is supported by both lubricating film and contacting asperities, a special procedure is provided to estimate the load supported by the asperities, because it is only that part of the load which contributes to the wear. The catastrophic form of wear in lubricated contacts, that is termed ‘scuffing’, is also considered, and the probability of scuffing, under a given set of operating conditions, is estimated. The predictive system has been tested and its predictions are compared with available experimental results.