封闭行星齿轮传动溜放型卷扬机设计

本文介绍了国内外溜放型卷扬机常用传动结构。对技术性能指标先进的封闭行星齿轮传动溜放型卷扬机设计,简介了相应的概念和有关计算公式,给出了设计步骤和计算实例,可供设计时参故。     

工程机械液力变速器(第四讲)——行星齿轮变速器分析方法

行星变速器比较复杂,不如定轴式变速器直观易懂.因此有必要介绍一下行星变速器的分析方法.分析行星变速器,首先应根据行星变速器的实物或结构图,画出其传动简图.图1为CAT980装载机行星变速器传动简图.根据图1传动简图可知它是两个行星变速部分串联组成.     

丹纳赫传动推出ValueTRUE经济型行星减速机

全球领先的运动控制解决方案提供商丹纳赫传动（Danaher Motion）公司又宣布推出Micron ValueTRUE行星减速机。VlalueTRUE是丹纳赫传动Micron True行星减速机系列产品的新成员，性能可靠，价格优势明显。Micron True行星减速机系列有1000种以上不同尺寸和减速比的产品可供选择，是世界上可选范围最大的行星齿轮减速机系列产品之一，     

起升机构的模糊可靠性优化设计

在普通优化设计的基础上，依据２统计理论和模糊原理，由可靠性设计准则，对起升机构常用的行星齿轮减束装置进行模糊可靠性优化设计，充分了影响行星齿轮传动的种种模糊因素，使优化符合实际。     

电传动自卸车轮边减速器齿轮修形优化

轮边减速器是电传动自卸车等大型工程机械的关键核心部件,其品质直接决定着整车性能和可靠性.由于矿岩具有较大的密度且矿区条件差异较大,电传动自卸车运行环境恶劣,轮边减速器输出扭矩大,长时间运行后容易出现齿轮点蚀、磨损、断裂等故障.本文针对低速级太阳轮大修周期出现齿面点蚀问题,通过基于行星轮系系统有限元分析,找到电传动自卸车轮边减速器低速级太阳轮齿面点蚀故障的原因,提出齿轮修形优化改进方案,为提高电传动自卸车轮边减速器齿轮使用寿命提供了理论依据.     

ZL系列装载机变速操纵阀故障分析

ZL系列装载机目前普遍采用行星齿轮动力换挡变速器,这种变速器结构紧凑、传动效率高且便于换挡。由于变速操纵阀在装载机作业过程中使用极为频繁,因此,由它引起的故障也较多,现将其常见故障及排除方法介绍如下。     

溜放型卷扬机在采用封闭行星齿轮传动机构时的循环功率分析

本文简介了封闭行星齿轮传动中循环功率的概念,推导出循环功率是否存在的判别式,简明直观,给出实例说明其应用,可供设计时参考。     

2K-H型行星齿轮系传动的优化设计

通过对2K－H型行星齿轮系传动的分析，建立了以体积最小为目标的数学模型，利用复合形法进行优化计算并设计了应用程序，最后对优化结果进行分析比较。     

16t轮胎式挖掘机制动限速降挡控制

1 行星式动力换挡变速箱的结构传动原理及降挡限速要求 目前用于轮式液压挖掘机的行星式动力换挡变速箱有多种结构型式,如ZF公司的ZHL系列、O&K公司的M96型等.图1所示为一种用于国产16t轮式液压挖掘机上的行星式动力换挡变速箱.图中太阳轮1经花键套与液压马达3相连,内齿圈4的内外圆都有花键齿,经内外多盘离合器5和6分别与花键套2和壳体7结合或分离,在内齿圈4和太阳轮1之间有3个行星轮8分别安装在行星架9的3个轴伸上,与内齿圈和太阳轮啮合,行星架为该行星变速轮系的输出端,它再经过齿轮10、11、轴12分别传动前后桥,驱动整机行驶.     

行星变速器传动方案串联综合法

应用行星变速器结构链，介绍了由二自由度变换器传动方案串联组成三自由度行星变速器传动方案的综合法，并给出了三、四行星排串联综合法变速器可能的传动方案。     

浅析高速公路工程招投标中的最低评标价法

结合目前高速公路施工项目招投标活动的实际情况,阐述了最低评标价法的概念,归纳了其优点及存在问题,对完善最低评标价法提出几点策略,以期促进招标投标市场更加规范有序。     

Place-Making in Megaprojects in Melbourne

This article analyses state-led place-making practices in Melbourne. The two levels of government that influence planning in Melbourne make much of the city as ‘culturally vibrant’ and ‘creative’, and have incorporated creative city-inspired place-making principles into many layers of the planning system. An examination of the development of two mixed-use megaprojects in central Melbourne reveals however that ideals of culturally engaging public places, and indeed of creative landscapes for middle-class consumption, wither in the face of more basic imperatives for economic development. In these case studies the ‘creative city’, no matter how the idea is interpreted, has little traction either as a set of inclusive place-making principles or as a gentrification strategy. The article concludes that the creative city-inspired place-making objectives in the planning system at both state and local levels are ambiguous in their overall intents and completely unsupported by statutory controls. Such place-making objectives as are realised are the compromised results of the interplay of uncoordinated decisions, delivered at the pleasure of the developer.     

Pathogens in septage in Vietnam

Septage is widely acknowledged as a major source of infectious pathogens while disposal of septage, and the operation and maintenance of septic tanks, is not regulated in many developing countries. Twenty untreated septage and septage sludge samples were taken from Can Tho City, Vietnam to examine their pathogen content, and indicator micro-organisms. Escherichia coli and Enterococcus spp. were detected in all samples, regardless of sludge storage time. Phages were detected in 80% of samples. Salmonella spp. were detected in 70% of the untreated septage and 60% of septage sludge samples. Concentrations of phages and bacteria tested in septage sludge after many years of tank storage were much higher than the expected levels. Helminth ova were present in 95% of untreated septage samples with an average of 450 ova l^− 1, and were detected in all septage sludge samples with an average of 16,000 ova l^− 1. Twelve varieties of helminth ova were identified. More helminth ova varieties in higher concentrations were found in septage than those reported from stool samples. The varieties' frequency ranged from 10% to 50% and Ascaris lumbricoides predominated. Results show that pathogens and indicator micro-organisms, especially helminth ova, accumulate in sludge. Thus helminth ova should be considered when septage sludge is treated and used for agriculture. Proper health protection measures must be applied for people handling septage.     

在市场中实践在实践中学习在学习中进步--工程公司市场化进程的回顾与展望

近两年来，工程公司在提高市场竞争意识、推动市场化进程中做了大量工作，其中坚持走出去的方针是我们自我加压、推行加快市场化步伐的一个重要战略步骤。     

新时期广东城市化的新特点

新时期广东城市化出现以下特点:知识源导向、城市由单体向群体化发展、产业集群推动、政府主导自上而下的集约化发展、城镇化向城市化转变、由重“数量”发展向重“质量”发展的转变。     

新形势下高校强化基建财务管理的探讨

在市场条件下高校基建财务人员在加强日常财务管理的同时,必须树立起高度的工作责任心,抓好事前监督、事中监督、事后监督三个环节,全面理解、贯彻执行《高等学校财务制度》,管好用好各项基本建设资金,提高基建财务管理水平,更好地完成高校各项基建任务,以有限的投资,最快的建设速度,获得最大的投资效益。     

2005年北京办公物业市场七大趋势

趋势一:CBD区域写字楼集中放量从各区域规划方案上看,CBD区域多数项目在03～04年处于项目的报批手续及拆阶段,预计2005年正式推向市场,因此2005年CBD区域将成为北京市场供应集中的域,区域即将供应的项目有北京财富中心(二期)、金地国际花园、万达广场、SOHO尚都、万通中心、世纪财富中心、怡禾国际中心、光华国际等。除去未知项目,2005CBD写字楼办公面积的供应量为60万平方米左右。中关村区域经过一段时间的集中供后开始逐步放缓,2005年供应的体量相对较大的项目有中关村金融中心、新中关。金街区域可能开盘的项目只有2个:英蓝国际中…     

浅谈我国工程项目建设成本控制存在的问题

结合目前我国施工企业工程项目成本管理现状,对工程项目成本管理过程中存在的问题进行了较详细的分析,并提出了一些解决问题的办法,以做好项目成本控制工作,进而增强企业经济实力。     

Variation in property taxation in Tulsa

Conclusions It may be reasonably concluded from this study that the range of variation in these ratios of assessed to actual value are of a reasonable size for the great majority of cases. The frequency distribution of these sample ratios was not normal, however, as was assumed a process of this type would produce. On the other hand, the failure of the regression analysis to identify any significant variables which would explain these variations would tend to re-enforce the assumption that the fluctuations were indeed of a random nature.To sum it up in one paragraph, aside from a few extreme cases, the assessing process appears to give estimates which are more consistent than would be expected under the assumption that any errors would be of a random nature, but the regression analysis was unable to isolate any particular socioeconomic characteristics which would explain the variation which was present.Financial support for this research project was furnished by the University of Tulsa.