对油隔离泥浆泵减速箱“十字头”滑道孔磨损量补修方法

文章对造成油隔离泥浆泵减速箱“十字头”滑道孔磨损原因进行了分析,结合生产维修实践比较了三种补修方法的可行性、经济性。详细阐述了靠“十字头”补修弥补滑道孔磨损的方法,并在实践中得到了验证。为同行业同类型设备维修提供了经验。     

毛轧机导卫板改进材质试验情况

北京第一轧钢厂三车间中轧机2、4架进口导卫夹板的材质是普通灰口铸铁,使用起来磨损严重,每班每个嘴子需要更换2～3次,每个月需要数百付。这样,不但影响作业率,磨损严重致使发生“倒钢”工艺事故造成废次品,而且给铸造工人和备件工人增加许多工作量,提高了劳动强度。为了     

矿井提升机闸瓦磨损保护仪研制成功

据不完全统计 ,近 10年来仅我国煤炭行业提升机因闸瓦过度磨损造成制动力不足引起的特大事故有 2 3起之多。有关安全规程明确规定 :“闸瓦过磨损保护应当在闸瓦磨损超限时能报警或自动断电。”目前 ,国内尚无定型的提升机闸瓦过磨损保护装置 ,TKD -A系列提升机自带的电器控制回路中的闸瓦磨损开关是一种常用的微动开关。该微动开关直接安装在电压为 110V或 2 2 0V的安全回路中 ,由于安装空间小 ,极易发生接地短路事故 ,并易在擦车时碰掉接线 ,且不具备在闸瓦过磨损时报警和自动断电功能 ,因此在使用中存在极大的安全隐患。兖州矿业 (集团…     

油隔离泥浆泵减速箱“十字头”滑道孔磨损后的补修方法

我厂在熟料窑喂料和赤派外排工序中，共使用了三种规格、14台油隔离泥浆泵。油隔离泥浆泵采用汽轮机油作为隔离介质，使浆体不直接进入活塞缸，减少磨损部件，提高使用寿命，能够比较平稳、经济地完成高扬程、大流量浆液输送任务，大大优越于离心矿浆泵和一般往复泵。但由于操作控制不当，活塞缸串料和拉杆盘根泄漏时常造成减速箱“十字头”与滑道接触都磨损，引起“十字头”轴线与活塞缸轴线不同轴（见下图），使得活塞皮碗和盘根密封圈磨损快，维修频繁，易串料、漏油，油耗高，形成恶性循环。一对减速箱“十字头”滑道孔磨损量的补修方法…     

1 250 mm热连轧工作辊磨损控制策略

 国内大量的1 250 mm热轧机精轧机组普遍使用带有负凸度的凹形工作辊,由于轧机辊形配置及轧制工艺特点,工作辊出现严重“猫耳”型磨损,造成轧制带钢断面出现局部高点现象。为改善1 250 mm热连轧工作辊的磨损,提升带钢板形质量,提出了一种适用于1 250 mm热连轧工作辊磨损的控制策略,在保证板带稳定轧制的同时,通过轧辊辊形和工作辊窜辊策略优化来控制工作辊的磨损。本策略已应用于德龙钢铁有限公司轧钢厂,工业试验表明,该策略可减小工作辊磨损量,使轧辊磨损更加均匀,增加弯辊力调控能力,并使工作辊单位周期轧制带钢长度延长40%,对1 250 mm热连轧产线工作辊磨损控制具有研究价值和推广前景。     

热轧带钢轧辊磨损与起筋现象分析

结合2250mm热轧带钢生产线实际情况,对热轧带钢在冷轧过程中产生的“起筋”现象进行了分析。通过对轧辊磨损数据的统计分析,分析了轧辊磨损与带钢“起筋”的对应关系,针对轧辊的“猫耳”磨损情况,进行了原因分析,并采取了有效措施,对热轧工艺和PCFC模型控制进行了优化改进,取得了很好的效果,改善了产品质量。     

橡胶缓闭止回阀获专利

由江苏亚太泵业有限公司研制的“XF”橡胶缓闭止回阀”，采用全橡胶结构，外形呈“鸭嘴状”，具有“正向排流，反向止回”功能，可解决传统给排水阀门运行状况不良、泄露大、铰链销易锈蚀、渣质沉积、阀座磨损、需经常维修更换等技术难题。实用于化工等污水处理工程的各种出水排放口，防止倒灌、倒流，可以避免造成二次污染。目前已获得国家实用新型专利证书。     

热连轧支撑辊剥落的原因分析

本文对梅山1422热连轧支撑辊剥落掉块和辊身边部“掉肩”进行了深入的分析,结果表明加工硬化、磨损不均匀、接触疲劳、辊身边部倒角设计不合理及工作层内缺陷是造成轧辊剥落的主要原因。并结合生产实际提出合理的使用维护方法与预防措施。     

发动机磨损原因分析

矿用汽车发动机经常在非稳定的动载荷下工作,因此造成发动机磨损的原因很多,只有找出造成发动机磨损的原因,才能采取有效的措施提高发动机的使用寿命.     

高锰钢加Cr——延长耐磨件寿命

用高锰钢制作的耐磨铸钢件,在冲击磨粒磨损条件下,显示出良好的性能,广泛地应用在采矿、冶金、建筑和机械等行业上。但现场使用条件不同,其磨损类型不一样,因此耐磨件使用寿命也不相同。一般对冶金矿山用耐磨铸件,根据使用中受冲击载荷大小分为两种磨损类型,一种是受冲击载荷大的“破碎性磨损”,如各种破碎机耐磨件;一种是受冲击载荷较小或无冲击的“碾磨性磨损”,如各种磨矿机耐磨件。     

双联叶片泵叶片早期磨损原因分析研究

双联叶片泵的早期磨损现象在SF31904型矿用自卸车上非常严重,为了探究其原因本文从油液污染和磨损两方面对其进行分析,通过对取样油液的化验,发现油液污染非常严重,油液中存在大量的硅和钙的化合物等高硬度的摩擦材料,油液的固体污染等级为NAS163812级,在标准中是最高污染等级,再通过叶片的磨损对比、对照实验及理论分析和推理得知其磨损量和磨损系数都较同等条件下的干净油液大了很多,而叶片的运行寿命则短了很多,这说明污染已成为影响叶片寿命的主要原因。     

烧结设备易损备件研究及对策

介绍了烧结易损备件失效原因分析，影响备件使用寿命的因素、防止实效对策，以及在生产实践中存在的问题，研究改进内容、改进后的效果和今后的研究方向。     

Tick-borne encephalitis (TBE) epidemiology in the Brest Province of the Republic of Belarus

BACKGROUND: Lens adherence and a reduced postlens tear film circulation have been suggested as factors contributing to some adverse reactions in extended wear of hydrogel contact lenses. In this study, we determined lens fitting and postlens tear film characteristics during closed-eye wear. METHODS: Twenty subjects wore hydrogel lenses for 3 h of eye closure, followed by 30 min of open-eye wear. Lens movement was measured with a video biomicroscope. Postlens tear film appearances in specular reflection were classified as either amorphous, or as one of four color intensity grades, where a colored appearance was taken as indicative of a depleted postlens tear film. RESULTS: All subjects showed lens adherence (movement < 0.1 mm) and postlens tear film depletion within 45 min of eye closure. These changes were sustained for the remainder of the closed-eye period, but were reversed within 15 min of eye opening. Lens adherence was associated with colored postlens tear film patterns of any intensity. CONCLUSION: Closed-eye wear was invariably associated with the onset of lens adherence and postlens tear film depletion. This finding emphasizes the need for adequate lens movement during the open-eye phase of extended wear.     

Correlation of tear clearance rate and fluorophotometric assessment of tear turnover

BACKGROUND: The study sought to determine dynamic changes and theoretical bases of a clinical diagnostic test, the tear clearance rate. METHODS: Thirty four healthy subjects ranging in age from 22 to 84 years underwent examination of tear clearance rate, the Schirmer test with anaesthesia, as well as fluorophotometric measurement of tear turnover, tear volume, and tear flow. By applying 0.5% fluorescein into the conjunctival sac and subsequently measuring colour fades on a Schirmer strip, the tear clearance rate for assessing tear drainage was divided into nine grades. The results of the tear clearance rate were compared with those of the basal tear turnover and tear flow obtained from fluorophotometry. RESULTS: Significant relations were found between the tear clearance rate and the basal tear turnover or tear flow (r = 0.91 and 0.79, respectively, p = 0.0001). Considering the grades of progression from low to high, each grade of tear clearance rate showed a 12.5% increase in basal tear turnover (3.59%/min) and tear flow (0.38 microliter/min). There was no significant correlation between age and the basal tear turnover, tear volume, tear flow, or the tear clearance rate. CONCLUSION: The tear clearance rate is proposed as a simple and useful way to estimate basal tear turnover and tear flow, and measure tear drainage indirectly.     

带式输送机输送带磨损及防范措施

通过对带式输送机输送带磨损形式的分析,在带式输送机的设计中采取相应的措施,来防范输送带的过快磨损,以延长带式输送机的运行寿命。     

齿轮的磨损失效及修复

本文主要针对冶金、矿山行业所广泛应用的齿轮在磨损失效之后的修复进行了探讨。这些齿轮直径大,承受载荷大,易于磨损,为避免不必要的损失,对磨损失效的齿轮进行修复,既节省资金又节省时间,最大限度的挖潜增效,从而取得更大的经济效益与社会效益。     

三相异步电动机损耗、效率和负载率分析

对三相异步电动机在不同负载率下的损耗和效率进行了分析,叙述了电动机是否经济运行的判别方法,以计算实例论证了电动机匹配性更换与高效再制造的节能效果。     

Analysis and design of flashtubes for pressure letdown in autoclave leaching operations

Theory and methodology have been developed to control slurry flashing during pressure letdown following high-pressure acid leaching (HPAL) of nickel laterites and pressure oxidation (POX) of refractory gold ores in order to minimize wear and tear of flash vessels and to facilitate steam/slurry separation. This is accomplished with the use of a “flashtube”, which is a valve-and-choke assembly which is specially contoured to control the expansion rate of the flashing slurry. By expanding the flow sufficiently to form a shock wave within the flashtube, it is shown that the amount of kinetic energy released at the flashtube exit can be reduced by nearly two orders of magnitude for a typical case.     

滚动轴承在推焦机辊体上的应用

分析了造成余煤回送托、压辊及推焦杆挡辊轴承磨损严重的原因,提出了改进措施,实施后取得较好的效果。     

Molecular wear and tear leads to terminal marking and the unstable isoforms of aging

Our studies focus on the mechanisms of molecular wear and tear, terminal marking, protein degradation, and how these processes are altered with age. Molecular wear and tear directly links catalysis with postsynthetic terminal marking. For example, the binding of ligands and catalysis cause conformational changes that are transmitted from the catalytic center to the site of terminal marking and enhance the rates of specific covalent modifications, such as deamidation or oxidation. These oxidations or deamidations can introduce "KFERQ motifs" into proteins, which may permit them to be recognized and transported to the site(s) of complete degradation. Terminally marked proteins accumulate in aging cells and tissues and account for many of the health problems of the elderly. Two-dimensional protein fingerprinting coupled with immunostaining permits identification and characterization of these proteins. Free-radical traps or caloric restriction, which may prevent the formation or enhance the degradation of terminally marked proteins, may be useful in the prevention or treatment of age-associated health problems, including dementia.