鼓形齿式联轴器失效分析

鼓形齿式联轴器在韶钢二轧厂应用中出现联接螺丝断裂、孔壁变形及扫齿等导致联轴器失效，针对上述问题进行了力学分析及强度校核，找出了失效原因，并采了牟相应解决措施。     

鼓形齿联轴器的安装及维护

本文通过介绍鼓形齿联轴器的适用范围、安装方法、安装参数、失效模式和日常维护内容,规范鼓形齿联轴器安装及维护要求。     

SJ12000风机联轴器损坏原因综合分析

本文对损坏的SJ12000烧结风机联轴器进行了综合分析，认为联轴器主动轴端的外齿套破裂属一次性正应力过载破裂，直接原因是材质没有达到设计的技术要求。内齿套则是在外齿套失效的情况下损坏。[第一段]     

鼓形齿联轴器及其国产化

鼓形齿联轴器及其国产化易荣祥（江西贵溪冶炼厂）在机械传动中，联轴器作为传递运动和动力的一种装置是必不可少的。我们厂引进日本国的成套设备中，同时带来了一些辅助装置，其中就有鼓形齿联轴器，这种联轴器是一种新型的挠性联轴器。１鼓形齿联轴器的结构及特点鼓形齿...     

新钢连退机组5号张力辊鼓形齿联轴器失效原因及处理

介绍鼓形齿联轴器的特点,就新钢冷轧生产线连退机组5号张力辊鼓形齿联轴器失效的问题,根据赫兹接触理论,结合设计参数和实际工况对齿面接触应力进行校核计算。计算结果和实际生产情况表明,接触强度足够是保证鼓形齿联轴器正常工作的必要条件,而不是充分条件。要提高联轴器的使用寿命,除了必须保证设计强度外,更要合理选择齿轮的材质、加工制造和热处理工艺,确保齿面的硬度和粗糙度,同时还要重视联轴器同轴度的校正和齿轮的加油润滑工作。     

梯形齿联轴器在轧机上的应用

针对某钢厂采用方形键连接来传递转矩的万向联轴器其方形键连接处承载受力面小，受剪切力和挤压力的作用而失效的问题，改用梯形齿连接后，加大了承载受力面抗剪切和抗挤压的能力，减少了设备故障发生，提高了万向联轴器的使用寿命。     

弧形齿联轴器轮齿载荷分布研究

根据轧机菜齿联轴器的结构特点，给出了一种分析菜齿联轴器倾角及周节积累误差对其齿对载荷分布影响的实用有效方法。利用这一方法分析了一典型联轴器主从动轴倾角与周节积累误差两因素单独或共同影响时的载荷分布规律及最大载葆因数，并给出了实际工况下最大载何因数的经验公式，为实际工程中的菜齿联轴器强度校核提供了依据。     

齿式联轴器的改造设计及应用

通过对齿式联轴器寿命不足问题的分析，提出设计非标准联轴器方案，提高齿部的抗弯曲强度。从而延长其使用寿命．满足轧钢生产需要。     

一起过盈联接失效的分析及处理

分析了沈阳鼓风机厂产品ＤＨ８０—１５ 型空压机联轴器因过盈配合不当而造成联接失效的原因．通过详细的计算及校验，重新选择了过盈配合尺寸，解决了打滑联接失效的问题．     

QL19-XG改进型滚珠联轴器在棒材厂650轧机上的应用

针对棒材轧机齿型联轴器在使用中存在的问题．论述了改进型滚珠联轴器的安装、使用方法及应用效果。     

十字轴式万向联轴器长寿命服役的技术控制

为使十字轴式万向联轴器长寿命服股 ,提出了设置转矩测试系统控制转矩 ;通过监测输入及输出设备的位置控制联轴器的空间位置 ,以减少附加力矩的影响 ;控制平衡力及轴承间隙等技术控制措施 ,避免联轴器过早失效或损坏。     

浅谈频谱分析在离心通风机中的应用及实践

In this paper, the working principle and basic structure of the centrifugal fan are introduced, and the main causes of the vibration failure of the centrifugal fan and the related characteristic frequency are expounded. By quoting the typical failure cases of fan,the misalignment of fan coupling and rotor imbalance and bearing failure are analyzed and diagnosed. Adopting the spectrum analyzer to collect data, the cause of equipment failures are found out accurately to solve the problem of equipment failure.     

八钢新区高炉鼓风机站送风机液力耦合器故障诊断分析

送风机液藕为调速型液力偶合器,是介于电动机和工作机之间的一种通过液体传动而实现无级调速的柔性传动装置。它可在恒速电机驱动的条件下,由电动执行机构操纵勺管来调节工作腔（泵轮与涡轮间）的充液量,从而任意改变工作机转速。动力传动平稳可靠,转速调节灵敏精确,可广泛用于风机、水泵、皮带机等负载。准确分析解决液力耦合器的故障是风机稳定运行的重要保证。     

圆螺纹套管的滑脱机理研究

连接接头滑脱失效是圆螺纹套管损坏的主要形式。利用弹塑性有限元法,研究了圆螺纹套管接头发生滑脱失效的过程与机理,然后通过全尺寸试验,分析了这种接头在失效过程中的应变分布及变形情况,并验证了有限元结果。研究表明,圆螺纹套管滑脱失效最先发生在啮合大端的第1、2牙螺纹上,设法提高此处螺纹的承载能力,对提高圆螺纹套管的连接强度具有重要意义。     

考虑热固耦合作用的高温高压井井筒完整性分析

以高温高压井套管-水泥环-地层为研究对象,建立套管-水泥环-地层组合系统的热固耦合模型,结合边界条件和连续条件,得到相应的应力解析解,并与有限元结果进行对比,验证了解析方法的计算精度.通过分析热固耦合作用下的解析解和不考虑热载荷的解析解,发现热载荷对整体等效应力的影响较大.采用Mises、Drucker-Prager及Mohr-Coulomb屈服准则定义失效系数评价套管-水泥环-地层组合系统的井筒完整性.讨论了水泥环弹性模量、泊松比、非均匀地应力系数、地层温度、套管内压等参数对套管内壁、水泥环内壁及第一、二胶结面失效系数的影响.上述因素对套管内壁、水泥环内壁及第一、二胶结面失效系数均有影响;第一胶结面失效系数较高,对井筒完整性影响较大.      

油套管螺纹连接抗粘扣技术的研究现状及展望

螺纹粘扣作为油套管中最常见的失效形式，一直是国内外冶金和石油系统的研究重点。对油套管粘扣现象作了简单的解释，通过对国际上近20年来油套管螺纹连接抗粘扣技术研究情况的分析总结，归纳了各种关于管螺纹粘扣失效的机理研究、管螺纹参数优化及其检测研究、螺纹脂和螺纹镀层的研究、油套管特殊螺纹连接的研究、油套管上卸扣的操作规范的研究，介绍了其主要研究成果，指出存在的问题，并探讨了进一步开展研究的方向。     

Comparison of ozone-induced effects on lung mechanics and hemodynamics in the rabbit

The objectives of this research were to determine the contribution of excitation-contraction (E-C) coupling failure to the decrement in maximal isometric tetanic force (Po) in mouse extensor digitorum longus (EDL) muscles after eccentric contractions and to elucidate possible mechanisms. The left anterior crural muscles of female ICR mice (n = 164) were injured in vivo with 150 eccentric contractions. Po, caffeine-, 4-chloro-m-cresol-, and K+-induced contracture forces, sarcoplasmic reticulum (SR) Ca2+ release and uptake rates, and intracellular Ca2+ concentration ([Ca2+]i) were then measured in vitro in injured and contralateral control EDL muscles at various times after injury up to 14 days. On the basis of the disproportional reduction in Po (approximately 51%) compared with caffeine-induced force (approximately 11-21%), we estimate that E-C coupling failure can explain 57-75% of the Po decrement from 0 to 5 days postinjury. Comparable reductions in Po and K+-induced force (51%), and minor reductions (0-6%) in the maximal SR Ca2+ release rate, suggest that the E-C coupling defect site is located at the t tubule-SR interface immediately after injury. Confocal laser scanning microscopy indicated that resting [Ca2+]i was elevated and peak tetanic [Ca2+]i was reduced, whereas peak 4-chloro-m-cresol-induced [Ca2+]i was unchanged immediately after injury. By 3 days postinjury, 4-chloro-m-cresol-induced [Ca2+]i became depressed, probably because of decreased SR Ca2+ release and uptake rates (17-31%). These data indicate that the decrease in Po during the first several days after injury primarily stems from a failure in the E-C coupling process.     

二炼钢铁水预处理除尘风机主轴的修复

因轴承润滑问题，二炼钢铁水预处理除尘风机主轴轴颈过热扭曲失效，在现场无备件而必须尽快恢复生产的情况下，大胆尝试过盈联接方式修配主轴，文章就主轴修配的过盈联接设计进行了详尽分析和计算，确保修复方案可行性和可靠性，并对修复实践进行了总结。     

The molecular and cellular pathophysiology of heart failure

In the United States, it is estimated that heart failure develops in 465,000 people each year. Heart failure occurs in both men and women and is associated with a high morbidity and mortality rate in both sexes and in all races. Our knowledge of the pathophysiology of heart failure has advanced beyond the cardiorenal-neurohumoral model and now includes changes in myocyte structure and function. Cellular changes in heart failure include myocyte hypertrophy, abnormalities in calcium homeostasis, excitation-contraction coupling, cross-bridge cycling, and changes in the cytoskeletal architecture. Data also indicate that some of these changes are found during the compensated stage of heart failure; whereas other changes are found during overt decompensation and are associated with changes in systolic and diastolic function. The transition from compensated to decompensated heart failure is more than likely related to the overexpression of neurohormones and peptides such as norepinephrine, angiotensin II, and proinflammatory cytokines. The purpose of this article is to review the epidemiology and cellular pathophysiology of heart failure.