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1.
余桂才 《机械工人(冷加工)》2004,(11):80
近年来,桂林机床股份有限公司为适应市场经济的激烈竞争,大胆实施了具有自身特色的“人才工程”,构筑了基本适应市场需要的人才选拔、培养、使用、吸引的激烈机制,做到了不但要经营好产品,还要经营好人才,促进了企业以信息化带动工业化,用高新技术改造传统产业,实现了产品升级换代,提高了企业核心竞争力,使企业闯出了一条不拘一格培养和使用人才的新机制。 相似文献
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针对现有的核电厂地震加速度计的标定方法无法同时涵盖规范规定参数检定要求,也无法实现核电现场就地标定检测的问题,设计了一种基于柔性金属弹片悬挂结构的便携式振动台,分析了振动台的机械结构,给出了振动台动力学方程;依照实际工程应用需求,选取了合适的参数和材料,进行了振动台的三维建模和有限元分析,制造了振动台样机,并对样机进行了测试,测试结果表明,振动台固有频率在1Hz以下,量程可达到1g,横轴灵敏度小于1%,净重在40kg以内,具备便携式特征,满足核电厂地震加速度计的现场标定参数检测的要求。 相似文献
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Grove45 t起重机主要负责煤炭港务公司的维修作业任务,由于设备故障频发,尤其是发动机故障率极高,严重影响设备完好率和吊卸生产作业效率,经常发生停机、机损等事故,严重影响了车辆的使用寿命,造成巨大的经济损失。基于此,通过理论研究与升级改造,实现了起重机发动机与液压系统以及负载的最佳功率匹配,使发动机运行在最优工作区,很大程度节省了燃油消耗,减少了尾气污染排放,尾气排放标准由改造前的国Ⅱ提升至国Ⅲ标准,同时降低了发动机运行故障,延长了其使用寿命,节省了故障维修成本支出。 相似文献
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基于螺旋传动机构设计了一种用于巡检机器人的升降装置。首先,根据具体的设计需求确定了升降装置的整体结构,并对其工作空间进行了简要分析。对升降装置进行了运动学分析,建立了运动学模型,并利用MATLAB进行了运动学仿真,确定了升降速度与减速电机输出转速之间的关系。然后,利用ANSYS软件对螺杆螺母组成的螺纹连接模型进行了有限元应力分析,验证了该升降装置设计的可行性,并通过对螺纹杆进行模态分析,验证了其升降工作的稳定性。最后,进行了螺旋传动机构实物样机的研制,并对升降装置整体安装实物进行了测试试验,验证了该升降装置设计的合理性。 相似文献
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江彦 《中国制造业信息化》2009,(1):65-65
与ERP、PLM等产业不同,OA应用发展了多年,产业边界依然不明确、不清晰,用戴珂的话说,过去,凡是没人管的都是OA.什么都做。与此相关,“协同”概念从点击科技开始提出到现在也已经有三、四年了,虽然业界“叫喊”了多年,但是,戴珂说:“由于理念不清,混淆了市场.误导了企业信息化的管理需求,也使得协同软件发展缓慢。厂商众多,“死不了,长不大”,产业积贫积弱。” 相似文献
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从1994年开始,历经十几载,曾经开发了基于DOS版本CAD软件,曾经在ACIS平台匕开发了Microsolid(美思),最终,又购买了ParaSolid核心,成功开发了Solid3000;从爱宜特,到友信,再到新洲,一路走来,在中国三维CAD软件产业发展进程中,契而不舍,不断探索,最终冲杀出一条可行之路。今天的新洲不能算是完全成功的企业,但是,它为中国CAD软件产业发展已经添加了浓重的一笔。 相似文献
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首先概述了工程机械维修领域的现状,接着描述了其中常见的问题,最后叙述了维修理论方法,并列举了实践手段,从而建立了完善的维修流程,对工程机械维修具有参考意义。 相似文献
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利用数控加工中心在深腔薄壁零件上制作小螺孔时,极易断锥,致使小螺孔加工成本增加,无法进行正常生产。针对该问题,从工艺角度进行了具体分析,确定了合理的加工工艺路线,设计了必要的夹具,确定了合理的切削工艺参数,并采用了挤压丝锥,避免了非正常断锥和螺纹烂牙,大幅度提高了加工小螺孔的效率。 相似文献
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用机械共混、冷压成型自由烧结的方法制备了MoS2、CdO和聚全氟乙丙烯填充聚四氟乙烯复合材料;用MM-2000型摩擦磨损试验机测试了在干摩擦条件下该复合材料的摩擦磨损性能;用扫描电镜(SEM)对磨损试样的表面形貌进行观察和分析.结果表明:未添加聚全氟乙丙烯的复合材料其摩擦磨损性能比添加的好;当CdO的体积分数为22.5%,MoS2的体积分数为7.5%时,复合材料的摩擦因数最小,抗磨性强,复合材料的摩擦磨损性能最佳. 相似文献
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Hai Zhao Jiaoqiang Zhang Tiezheng Ji Manhong Yang Min Chao Kaichang Kou 《Tribology Letters》2012,45(2):333-339
Polyimide/fluorinated ethylene propylene (PI/FEP) laminated composites were fabricated by means of hot-press molding. The
friction and wear behavior of high performance PI/FEP laminated composites has been comparatively evaluated under dry sliding,
water- and oil-lubricated conditions. The worn surface morphologies of samples under different lubrication conditions were
examined by scanning electron microscope and the wear mechanisms were comparatively discussed. As the results, PI/FEP laminated
composites sliding against stainless steel under water lubrication registered lower friction coefficients, but higher wear
rates than those under dry sliding. The friction coefficients and wear rates of samples under liquid paraffin-lubricated condition
were lowest in three sliding conditions. The lateral surface of samples exhibited better wear resistance than parallel surface
did under dry sliding. 相似文献
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Microstructure of PTFE-Based Polymer Blends and Their Tribological Behaviors Under Aqueous Environment 总被引:1,自引:0,他引:1
Four polytetrafluoroethylene-based polymer blends (PTFE blends) with polyimide (PI), polyether ether ketone (PEEK), poly(phenyl
p-hydroxybenzoate) (PHBA), and perfluoroethylene propylene copolymer (FEP) were prepared by compression molding and follow-up
sintering. Their microstructure was observed by scanning electron microscope. And the tribological behaviors of PTFE blends
sliding against 316 steel under pure water and sea water lubrication were comparatively evaluated using block-on-ring tribology
test rig. The worn surface of counterpart was examined by X-ray photoelectron spectroscopy. The results showed that by blending
with the four polymers, PTFE exhibited the transformed microstructure and improved wear resistance. Compared with FEP, rigid
polymers PI, PHBA, and PEEK can enhance the wear resistance of PTFE greatly because they can effectively improve the load-carrying
capacity of PTFE matrix and can more efficiently prevent the crystalline bands of PTFE from being pulled out. However, because
of the weak inhibition on the pulling out of PTFE crystalline bands, FEP cannot enhance the wear resistance of PTFE as significantly
as other polymers. In addition, the friction coefficients and wear rates of PTFE and its blends were lower under the lubrication
of sea water than under the lubrication of pure water, which was ascribed to more excellent lubricating effect of sea water
originating from the deposition of CaCO3 and Mg(OH)2 onto the sliding surfaces. 相似文献
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Friction and Wear Behaviors of Several Polymers Sliding Against GCr15 and 316 Steel Under the Lubrication of Sea Water 总被引:1,自引:0,他引:1
Ocean tribology, a new research field of tribology, is currently being established and developed. The tribological behaviors
of polyether ether ketone (PEEK), poly(phenyl p-hydroxybenzoate) (PHBA), polyimide (PI), and perfluoroethylene propylene copolymer (FEP) sliding against GCr15 and 316 steel
rings under the lubrication of sea water were studied and compared with that under the lubrication of pure water. The results
show that the friction and wear behaviors of a polymer under the lubrication of aqueous medium are not only related to the
properties of polymer itself, but also to the corrosive effect and lubricating effect of the medium. When a polymer slid against
GCr15 steel under sea water lubrication, the friction coefficient and wear rate of polymer were much larger than that under
pure water lubrication because of indirect corrosive wear. However, when sliding against corrosion-resistant 316 steel, polymers
PEEK, FEP, and PI exhibited lower coefficients of friction and wear rates under sea water lubrication, this was attributed
to better lubricating effect of sea water as a result of the deposition of CaCO3 and Mg(OH)2 on the counterface. On the contrary, the friction coefficient and wear rate of PHBA sliding against 316 steel under sea water
lubrication were larger than that under pure water lubrication, which may be related to the properties of PHBA itself. 相似文献
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V. A. Shuvalov N. A. Tokmak N. P. Reznichenko 《Instruments and Experimental Techniques》2016,59(3):442-450
A procedure of the physical (bench) simulation of the long-term interaction of polymer materials with flows of atomic oxygen and vacuum ultraviolet radiation in the earth’s ionosphere is designed. The efficiency of the bench measurements of mass losses of kapton-H and PM-1E polyimides, polyethylene, and FEP Teflon is confirmed by results of satellite measurements. The dependences of degradation of polymer films on the fluence of atomic oxygen are determined. They allow one to forecast time changes of mass and geometric characteristics of polymers during the whole operating period in the ionosphere. The synergetic effect of the action of the near-satellite environment on the ablation of the polymer films characterizes threshold ratio values of the vacuum ultraviolet energy flow to the atomic oxygen flow. 相似文献
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Boncheol Ku Youngdo Park Chiun Sung Youngchul Han Junghoon Park Yujin Hwang Jungeun Lee Jaekeun Lee Hyeongseok Kim Sungyoung Ahn Soo Hyung Kim 《Journal of Mechanical Science and Technology》2010,24(8):1631-1635
This study examined the tribological behavior of journal bearings made from polytetrafluoroethylene (PTFE) composites and aluminum (Al) alloys. The PTFE composite journal bearings consisted of a steel backing with a thickness of 1.6 mm, a middle layer of sintered porous bronze with a thickness of 0.24~0.27 mm, and a surface layer of PTFE filled with fluorinated ethylene propylene (FEP) powder and carbon fibers with a thickness 0.06~0.14 mm. The other was an aluminum alloy journal bearing consisted of a steel backing with a thickness of 1.5 mm and a surface layer of an Al-6Sn-6Si alloy with a thickness 0.35~0.75 mm. A series of lubrication tests were performed using a journal bearing tester under various normal loads. The tribological properties for each journal bearing were evaluated by measuring the lubricant oil temperature and friction coefficient as a function of the applied normal load. In addition, the chemical compositions and microstructures of the journal bearing materials used in this study was analyzed by inductively coupled plasma (ICP), optical microscopy (OM), and scanning electron microscopy (SEM), respectively. The experimental results showed that the Al alloy journal bearings reduce the friction coefficient by 28 % compared to the PTFE composites bearings. In addition, the Al alloy journal bearing worked properly at the maximum load of ~ 8,000 N without adhesion. However, the PTFE composite journal bearings exhibited strong adhesion at the loads ranging from 6300 to 8000 N. This suggests that the Al alloy is a more promising material in journal bearings than PTFE composites. 相似文献
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In a recent paper, the Ritz method with simple algebraic polynomials as trial functions was used to obtain an eigenvalue equation for the free vibration of a class of homogeneous solids with cavities. The method presented is here extended to the study of a class of non-homogeneous solids, in which each solid is composed of a number of isotropic layers with different material properties. The Cartesian coordinate system is used to describe the geometry of the solid which is modelled by means of a segment bounded by the yz, zx and xy orthogonal coordinate planes and by two curved surfaces which are defined by fairly general polynomial expressions in the coordinates x, y and z. The surface representing the interface between two material layers in the solid is also described by a polynomial expression in the coordinates x, y and z. In order to demonstrate the accuracy of the approach, natural frequencies are given for both a two- and three-layered spherical shell and for a homogeneous hollow cylinder, as computed using the present approach, and are compared with those obtained using an exact solution. Results are then given for a number of two- and three-layered cylinders and, to demonstrate the versatility of the approach, natural frequencies are given for a five-layered cantilevered beam with a central circular hole as well as for a number of composite solids of more general shape. 相似文献
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描述了用于K型热电偶回路中的镍铬接触对在电连接器的振动过程中发现接触电阻变大的失效现象,从接触电阻的理论构成和失效接触对的实物状态进行原因分析,通过更换绝缘体材料、固定接触对及更换接触对等方式进行试验验证,确定主要原因。针对分析结果,通过降低表面粗糙度、提高接触压力、涂覆固体膜润滑剂和调整接触对固定机构等方式,解决了镍铬接触对在振动过程中的接触电阻失效问题。通过一系列的试验,总结了避免镍铬接触对失效的关键措施。 相似文献