共查询到20条相似文献,搜索用时 62 毫秒
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高压电机定子线棒主绝缘成型多采用热模压工艺,热压模的设计与制造是高压定子线棒主绝缘热模压固化成型的核心技术。设计新型的定子线棒主绝缘热压模,采取外加热方式,液压夹紧,不用烘炉而改用热压机,一次安装能同时热压两条线棒。文中介绍了新型高压线棒主绝缘热压模结构特点、制造工艺和应用效果。 相似文献
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朱月龙 《机械工人(冷加工)》1977,(8)
车床调换卡盘,既费力又不安全。现用铁棒一根,直径小于主轴孔2-3毫米。为不使主轴孔划伤和手抓时光滑,棒二端车出圆头,棒的长度以伸进轴孔二分之一,卡盘前端出150毫米(手抓用)为宜(如图)。拆下卡盘时,先将卡盘夹紧圆棒,开始反转,完全脱牙后,用手抓圆棒二端将卡盘搬下。装上卡盘时,同样先夹紧圆棒,将圆棒一端塞进主轴孔内, 相似文献
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液压自动转位刀台的研制、解决了以往结构的传动路线长、占据机床内腔空间位置大、滑枕和刀台刚度低和刀合的夹紧力小的缺点。由于采用了液压力加蝶簧力夹紧,夹紧刚度高。实践证明本结构布局合理、夹紧力大、刚度高,适用于大、中型机床。目前已在CK8212、CJK576及CJK5112型数控型立车上得到广泛的应用。 一、工作原理及自动转位的控制 刀台的转让运动(分度运动)是由做直线运动的牙棒活塞8推齿轮7旋转,经定比传动来完成。刀台每完成一次转让动作,要经过下述三个过程:(1)刀台放松:由图1可见,刀台转位之前处于夹紧状态,此时行程开关13被压… 相似文献
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通常汽车齿轮加工工艺流程为:锻造→粗车→精车→滚齿→剃齿→热处理→磨棱→磨内孔→入库。热处理以后磨内孔是最重要的加工工序,直接决定汽车齿轮的加工质量和使用寿命。通常在斜齿圆柱齿轮(见图1)磨内孔时,首先找三个直径相同的量棒,然后依次把三个尺寸一致的节圆棒放置在三爪卡盘夹紧对应齿轮齿槽中,最后通过百分表校正加工齿轮端面,用三爪夹紧齿轮。每次通过放置不同节圆棒,完成不同汽车零件内孔的磨削。 相似文献
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金属圆柱棒的高速剪切断裂数值模拟及实验研究 总被引:2,自引:0,他引:2
介绍利用弹塑性有限元模拟金属圆柱棒的剪切断裂过程,分析高速径向夹紧剪切时材料断裂过程、材料破坏准则的选取等关键技术。应用单元消除法分析剪切裂纹的扩展,得到剪切各个阶段的金属流动、应力、应变的分布情况,并在棒料高速剪切机上进行实验研究,实验结果与模拟结果一致,从而验证采用径向夹紧的高速剪切工艺可以极大地提高剪切下料的生产效率和剪切断面质量。 相似文献
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毛善忠 《机械工人(冷加工)》2000,(3):17-17
一、传统的装夹方法 典型盘类齿轮零件及内孔磨削技术要求如图1所示。节圆对内孔的跳动t是加工控制的难点。传统的加工方法是以三根滚棒在工件节圆进行定位夹紧,如图2所示。这种装夹方法要求每次加工前用三根滚棒插在三个均布方向的齿槽中,并通过调整卡盘,用百分表校正滚棒跳动在要求的范围内,方 相似文献
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The tribological system in the piston assembly of an internal combustion engine includes contacts at interfaces of piston/piston ring/cylinder liner, piston skirt/cylinder wall, and piston/piston pin/ connecting rod. The thermal and tribological properties of the piston, piston rings, and cylinder wall are critical to the life and quality of the engine. Severe wear and scuffing failure, especially at the ring/ring groove and ring/liner interfaces, may present a major problem if the piston temperature is too high. Temperature considerations for the piston often limit the effort to increase the engine power. A new engine piston incorporating the heat pipe cooling technology has been developed for reducing the piston temperature, especially in the ring land and along the piston wall. The current work aims at investigating the effect of reciprocating heat pipes on heat conduction in the piston, and thus the tribological behavior of the piston assembly. Due to the high thermal conductance of the reciprocating heat pipe, a considerably large amount of combustion heat, which is conventionally conducted through the piston wall, is transferred through heat pipes. This new design will result in a lower temperature on the piston wall and a reasonably low temperature distribution in the piston. 相似文献
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为提高泥浆泵活塞使用寿命,模仿自然界生物体表形态,在现有泥浆泵活塞工作表面加工不同尺寸的凹槽形仿生单元体,在相同的试验条件下,对比研究泥浆泵仿生活塞与标准活塞的使用寿命。试验结果表明,合理的凹槽形仿生单元体设计可以明显提高活塞使用寿命,本研究中最大可提高BW-160型泥浆泵活塞寿命69.52%;仿生活塞使用寿命受凹槽宽度的影响大于凹槽间距的影响;凹槽形仿生单元体尺寸过小,活塞寿命提高不明显,凹槽形仿生单元体尺寸过大,反而降低活塞寿命。分析了仿生活塞耐磨机理,即凹槽形仿生单元体的存在,能优化活塞表面受力情况,增大储油空间,改善泥浆泵活塞缸套系统界面润滑条件,是提高泥浆泵活塞使用寿命的重要原因。 相似文献
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Il-Hyun Baek Ihn-Sung Cho Jae-Youn Jung Lu Hong 《Journal of Mechanical Science and Technology》2008,22(9):1726-1733
To improve the performance of the bent-axis type axial piston pump driven by the tapered piston, it is necessary to know the
driving characteristics and mechanism of the tapered piston and the cylinder block. Since each piston not only rotates on
its axis and reciprocates in the cylinder bore but also revolves around the axis of the driving shaft, it is difficult to
analyze the driving mechanism theoretically. The theoretical mechanism for the bent-axis type axial piston pump is studied
by using the geometrical method. The driving range of the tapered piston is determined by theoretical equations. The results
show that the cylinder block is driven by one tapered piston in a limited range and the core parameters such as the tilting
angle of the piston and the ahead delay angle influence performance of the bent-axis type axial piston pump. 相似文献
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活塞是内燃机的关键零件,为保证活塞在热变形下不被卡死,必须将活塞裙部在冷态下制成某种特定的形状,也就是说中凸变椭圆活塞将逐步替代传统的圆柱体活塞。本文根据活塞的结构特点,对其加工工艺进行了分析,并对活塞的加工方法进行了研究比较,最后对现有活塞加工技术的不足进行了总结。 相似文献
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通过改造潍柴WP6发动机的供油、燃烧系统,开发出一台二甲醚发动机。试验采集二甲醚发动机燃烧参数,针对活塞运动和润滑分析,建立活塞裙部系统以及由曲轴、连杆、活塞组成的多体系统的耦合润滑模型。基于拉格朗日乘子法建立多体动力学方程,并采用有限单元法对润滑模型进行求解。将耦合计算结果与实验对比,验证模型准确性。根据现有二甲醚发动机活塞裙部的结构参数,研究不同活塞结构参数对敲缸及润滑的影响。结果表明,活塞间隙越小时,活塞二阶运动的空间越小,导致敲缸现象减弱,磨损降低,但较小的间隙会产生比较高的油膜剪切力,微凸体表面接触也会加剧,引起较大的摩擦力及摩擦功耗;活塞裙桶形面最高点的位置也会影响活塞裙-缸套系统的运动和润滑特性;桶形面与活塞销中心的距离越小越容易满足力与力矩平衡条件,有利于降低敲缸以及摩擦损耗。 相似文献
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为实现水液压泵柱塞副的高效密封并自动补偿其磨损间隙,提出了一种柱塞副密封间隙自动补偿结构。通过流固耦合仿真技术研究了不同柱塞套厚度和环形槽宽度下柱塞套在内侧环形流体和外侧环形缝隙流体耦合作用下的变形特性。仿真结果表明,在相同的工作压力、流体域边界条件下,当环形槽宽不变时,随着工程塑料聚醚醚酮(PEEK)材质的柱塞套厚度的增大,柱塞套变形量逐渐减小;当柱塞套厚度不变时,柱塞套变形量随着环形槽宽的增大而增大。建立了柱塞副间隙自动补偿试验系统并进行了初步试验,试验结果和仿真结果基本一致。 相似文献
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IhnSung Cho IlHyun Beak JaeCheon Jo JuMi Park SeokHyung Oh JaeYoun Jung 《Journal of Mechanical Science and Technology》2010,24(6):1363-1368
The bent-axis type of piston pump driven by the piston rod works by the piston rod driving the cylinder block; because of
this the taper angle of the piston rod and the swivel angle between the cylinder block and the shaft are important design
factors. If these factors cannot satisfy the conditions for optimum design, the friction loss between the cylinder bore and
the piston increases, and the pump can fail to work under conditions of severe friction and wear. Since the piston reciprocates
in the cylinder bore with high velocity, at the same time rotating on its own axis and revolving on the center of the cylinder
block, a decrease of the volume efficiency is generated because of the leakage between the cylinder bore and the piston. Therefore,
to prevent this, the piston ring is designed to be at the end of the piston, and the friction characteristics between the
piston ring and the cylinder bore require further research due to their great influence on the performance of the piston pump.
Thus, in this paper, the elastohydrodynamic lubrication (EHL) analysis of the film thickness, the pressure distribution, and
the friction force, have been studied between the piston ring and the cylinder bore in the bent-axis type of piston pump.
The analyzed results show that the friction force is influenced by the rotating speed and the discharge pressure. 相似文献