共查询到20条相似文献,搜索用时 125 毫秒
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一、尺寸链的补偿形式 在导轨配磨过程中,由于相配导轨副各接合面的金属层被磨(有时磨量很大)掉,会使相关的尺寸链发生变化,以致影响安装精度,甚至无法装配。为介决这个问题,必须使被磨削破坏了的尺寸链恢复原位。而使变化了的尺寸链通过一定的技术手段重新恢复原始尺寸的过程, 相似文献
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以刮板输送机刮板链常见故障为切入点,分析了刮板链组件、接链环等故障类型,再以此为基础,重点论述各类故障的预防应对措施,结合实例对理论进行证明。以期通过明晰问题所在,为后续实际工作提供一定参考。 相似文献
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《机械工程与自动化》2018,(6)
对SGB620/40T刮板机机头进行改造,使SGB620/40T刮板机的机头实现了伸缩,消除了接链时的安全隐患,有效地减少了辅助工作时间,提高了生产效率。 相似文献
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管云华 《机械工人(冷加工)》1982,(1)
在煤矿机械中,链轮的种类很多,图1是20B型刮板输送机的五星链轮,采用组合夹具定位、装夹铣削链齿吻接圆弧面,既提高工效、又保证了质量,效果很好。下面简介该铣夹具的工艺计算、夹具结构和使用方法。一、工艺计算 相似文献
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北京手表厂近日推出一款掐丝珐琅手表,笔者有幸一睹芳容。这款手表搭配银坯掐金丝珐琅表盘,薄型手上弦机心,而珐琅表盘是整只手表的点睛之处……[编者按] 相似文献
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机构运动链结构简图的自动绘制,直接关系到机构设计的效率与可靠性。在对平面闭式机构运动链的拓扑特性研究基础上,基于缩杆邻接矩阵,提出一种运动链结构简图自动绘制的最大环路方法。此方法采用广度优先生成树算法获得运动链的独立回路,并通过独立回路的加减运算得到最大可行外环。根据回路关系逐步修正最大可行外环,使各独立回路成为其非交叉规范化内环。在运动链结构简图绘制过程中,根据外环和内环情况,将运动链中的运动副布置在由外往内的同心圆内接正多边形的顶点上,使绘制的运动链简图规范、美观。在对这种基于外环与内环关系的简图自动绘制算法研究过程中,借助多个机构实例进行说明。研究与应用结果表明,最大环路法具有实现简单、方法完备的特点,适用于多杆多自由度平面闭式运动链结构简图的自动绘制,应用于机构设计中,可极大地提高设计效率。 相似文献
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江苏射阳港发电厂是一座临海而建的燃煤火力发电厂,卸煤装置采用岸壁式悬链斗卸船机,整机运行方式为定机移船式。悬链斗卸船机由链斗机构、横移机构、移船机构、横带式输送机、斜带式输送机以及配重机构等组成,是一种高效连续式卸船机。卸船机以链条为牵引构件,以料斗为承载兼取料构件,料斗按一定节距固定在链条上,呈封闭环状,在煤层中靠重力自行取料,并将煤输送到接料带式输送机,再经过倾斜带式输送机运到后方输煤带式输送机。1运行情况射阳港电厂卸船机每年接卸原煤约180万t。目前卸船机的横带式输送机通过吊耳与悬臂梁连接,并随悬臂梁上… 相似文献
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The electrochemical behaviour of ferritic and austenitic phases in duplex stainless steel (UNS S32304) and the modifications induced by straining during sliding were studied by potentiodynamic polarisation curves determined at the microscale in a 1 M NaCl (pH 3) solution, using an electrochemical microcell. The mechanical properties and stress state of each phase were determined by microhardness and X-ray microdiffraction measurements, before and after straining. The results show that sliding generates elastic straining of the ferrite and plastic deformation of the austenite. The electrochemical behaviour of these phases is dramatically altered, inducing a reduction of the corrosion resistance and of the passivation properties. 相似文献
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对20CrNi3A的从动圆锥齿轮进行了硬度、化学成分、金相组织等进行了分析。结果表明:吃刀现象是由于在组织中存在着硬质相(马氏体相),导致加工时严重吃刀、机床颤动剧烈等现象的发生。 相似文献
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金属材料的疲劳稳定性 总被引:3,自引:0,他引:3
从能量的观点阐述了金属材料在循环变形过程中性能的变化及其微观机制。循环载荷一定时,对每一种材料在循环周次达到某一定值后都对应着一个稳定的微观结构和最稳定的能量状态。如果原始组织结构的能量较高,则循环变形过程中将会向低能结构转化,并发生循环软化;相反,则发生循环硬化,也有的材料组织结构很稳定,在一定的循环变形条件下能量状态和性能不发生明显的变化。 相似文献
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A method has been devised and demonstrated for producing in situ straining specimens for the transmission electron microscope (TEM) from specific locations in a sample using a dual-beam focused ion beam (FIB) instrument. The specimen is removed from a polished surface in the FIB using normal methods and then attached to a pre-fabricated substrate in the form of a modified TEM tensile specimen. In this manner, specific features of the microstructure of a polished optical mount can be selected for in situ tensile straining. With the use of electron backscattered diffraction (EBSD), this technique could be extended to select specific orientations of the specimen as well. 相似文献
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Yoshimasa Takahashi Masaki Tanaka Kenji Higashida Kazuhiro Yasuda Syo Matsumura Hiroshi Noguchi 《Ultramicroscopy》2010
A novel specimen holder that enables in situ observation of crack-tip deformation and/or fracture under a controlled environment is developed for a high-voltage electron microscope (HVEM). A window-type environmental cell (EC) that incorporates a uniaxial straining apparatus is built into a side-entry-type single-tilt specimen holder. The gas control in EC, straining apparatus design, limited field of view for crack-tip observation, and specimen preparation for the specimen holder are presented in detail. Experimental results successfully demonstrate that the developed specimen holder is quite useful for the dynamic observation of crack-tip deformation and/or fracture subjected to a hostile environment, such as hydrogen gas. 相似文献
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Dislocations in the spinodal alloy Fe(30)Ni(20)Mn(25)Al(25), which is composed of alternating BCC and B2 (ordered BCC) phases, have been investigated using weak-beam transmission electron microscopy (TEM). The alloy was compressed at room temperature in an as-hot-extruded state to strains of approximately 3% for post-mortem dislocation analysis. Dislocations with a/2<111> Burgers vectors were found to glide in pairs on both {110} and {112} slip planes. TEM in situ straining experiments were also performed on both the as-extruded alloy and an arc-melted alloy. The in situ straining observations confirmed that dislocations were able to pass between both spinodal phases. Partial dislocation separations were relatively wide in the BCC phase and narrow in the B2 phase. Dislocation glide, as opposed to twinning (both of which have been observed in other BCC-based spinodals), was also found to be the only room temperature deformation mechanism. 相似文献
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