联轴器与轴承拆装方法概述及要点分析

本文对联轴器、轴承拆装关键数据及理论计算依据进行了资料收集整理,总结以往的拆装经验,明确联轴器、轴承拆装方法及理论依据,为联轴器、轴承的可靠拆装提供参考和指导。     

大型减速机轴承游隙的调整方法

随着工业化的进一步发展,大型减速机在企业中的使用越来越广泛。文章分析了大型减速机在使用过程中最常见的轴承损坏故障原因,介绍了轴承游隙的调整、测量及轴承安装的方法。     

一次除尘风机稀油润滑系统的改进

通过更换供油泵和增加一个低位油箱,解决了在低转速下风机轴瓦和耦合器轴承的润滑问题,也杜绝了风机轴瓦漏油现象,确保了风机的正常运行。通过更换大容积高位事故油箱,为事故和故障的处理创造了条件,有效的防止了恶性事故的发生。     

带冷机传动链轮齿圈的剖分组装

为解决带冷机传动链轮齿圈吨位大，在大中修时施工难度较高，现场需整体拆装链轮组等困难，以及减少备件制做所占用的大量维修费用，本文介绍了采用剖分链轮齿圈组装的技术方法。该方法既可减少拆装的工程量，无需采用大型吊装机具，而且还可降低大修工程量并节约备件的制作费用，其组装质量完全能达到技术要求。     

轧机减速机轴承失效原因分析

轧机减速机的稳定运行是保证轧制正常进行的重要前提。通过理论与实践相结合的方式,针对棒材线中轧区水平减速机高速轴部件轴承损坏现象,从设备与工艺方面剖析轴承损坏机理,从而采取有效地改造方案对其改进优化。通过对减速机深入研究,制定两种更换高速轴部件轴承的方案：一是将SKF23230CC/W33轴承替换成NSK23230CAME4S11轴承;二是将SKF23230CC/W33轴承替换成FAG的F-674572.23130轴承。结果表明：通过更换高速轴部件的轴承,彻底消除了减速机设备运行隐患,有效地降低了设备故障率,为冶金行业减速机故障处理提供参考借鉴经验。     

交交变频双绕组电动机定子绕组故障局部修复实践

大型电动机定子绕组故障常规修复工作量大、周期长,生产难以承受。采取局部或应急修复方案可以快速恢复电动机运行并降低故障时间。介绍了交交变频双绕组电动机直接甩掉故障线圈应急修复的可行性及做法,实现了电动机的快速修复,且运行效果良好。对于类似故障处理具有较强的指导意义。     

自适应动模式分解和GA-SVM在行星轴承故障分类中的应用

行星齿轮箱在运行过程中由于齿轮间的相互作用会产生强噪声,导致行星轴承的故障特征被完全淹没在背景噪声中并难以提取,从而使得行星轴承故障分类的准确率较低.本文提出一种自适应动模式分解(ADMD)和遗传算法优化支持向量机(GA-SVM)的行星轴承故障分类方法.首先,针对传统动模式分解(DMD)中截断秩无法准确选取的问题,定义了一种新的适应度函数,并采用改进的蚱蜢优化算法(IGOA)自适应选取最优截断秩,进而实现对原始振动信号的降噪处理.然后对处理后的信号计算其归一化后的复合精细多尺度离散熵(IRCMDE)并构成特征矩阵.最后采用遗传算法优化支持向量机,构建GA-SVM分类模型,并将其应用到行星轴承故障诊断中.利用行星齿轮箱中行星轴承故障数据验证了此方法的有效性和实用性,最终分类结果为96.43%,表明了该方法可以准确识别出行星轴承的故障类型.     

桥式起重机卷扬筒装配结构改进

卷扬筒是起重机起升机构的重要部件。在日常的检修中,如更换起升机构中的易损件,势必涉及到卷扬筒的拆装,由于目前桥式起重机卷扬简装配结构设计的特点,使卷扬筒的安装和拆卸十分困难,我厂起重机检修工人在长期的经验积累中发现,只要在安装结构上稍加改进,增设一个轴承挡圈,便会使卷扬筒的拆装变得十分简便,拆装时间可从原来4小时缩短到1时左右。     

大型四列圆柱滚子轴承的应用

阐述四列圆柱滚子轴承的结构特点、拆装方法、润滑、密封与保养等;介绍了此种轴承在我厂铝板、带、箔材轧机上的应用情况,并分析了非正常损坏的原因.     

加热炉助燃风机振动故障案例分析

描述了加热炉助燃风机出现振动报警信息后,对助燃风机的在线监护和分析处理过程。在对助燃风机故障诊断过程中,利用轴承故障特征频谱对异常振动的原因进行分析,通过现场逐步排查,缩小故障范围,将故障类型定位于间隙和不对中,故障点锁定在止推轴承上。对该轴承进行更换后,最终恢复了设备的正常状态。     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.