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介绍了直线式全自动箱体发泡线充注机械手的结构及其驱动系统,该系统可直接应用在新箱体发泡线的制造上,又可用在老箱体发泡线的改造上,因此具有极大的推广价值和显著的经济效益. 相似文献
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通过比较铜线与金线的性能,论述了铜线压焊的特点、设备的改造、铜线产品质量检验与常见不良产品等,在晶体管产量较大时,使用铜线压焊能有效地降低生产成本,因而在通用民品中有着非常广阔的应用前景. 相似文献
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针对铣削加工中心主轴刚度检测系统实时性的要求,重点阐述了DSP FPGA的数字硬件系统和流水线结构的CORDIC算法在FPGA中的实现,并通过仿真和实验对CORDIC算法的理论值和计算数值进行对比分析,结果表明,计算数值非常接近理论值. 相似文献
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本文简要介绍了美国国家流体动力工程中心的基本情况、研究方向和教学计划.在此基础上对我国流体动力传动与控制的科研单位和企业的发展提出了一些看法. 相似文献
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通过对集中冷却式康明斯KTA-19发电机组在列车运行中出现的严重问题进行分析,并提出相关改进的建议. 相似文献
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REN Zunsong 《机械工程学报(英文版)》2013,26(3):518-525
The wheel-rail contact problems, such as the number, location and the track of contact patches, are very important for optimizing the spatial structure of the rails and lowering the vehicle-turnout system dynamics. However, the above problems are not well solved currently because of having the difficulties in how to determine the multi-contact, to preciously present the changeable profiles of the rails and to establish an accurate spatial turnout system dynamics model. Based on a high-speed vehicle-turnout coupled model in which the track is modeled as flexible with rails and sleepers represented by beams, the line tracing extreme point method is introduced to investigate the wheel-rail multiple contact conditions and the key sections of the blade rail, longer nose rail, shorter rail in the switch and nose rail area are discretized to represent the varying profiles of rails in the turnout. The dynamic interaction between the vehicle and turnout is simulated for cases of the vehicle divergently passing the turnout and the multi-point contact is obtained. The tracks of the contact patches on the top of the rails are presented and the wheel-rail impact forces are offered in comparison with the contact patches transference on the rails. The numerical simulation results indicate that the length of two-point contact occurrence of a worn wheel profile and rails is longer than that of the new wheel profile and rails; The two-point contact definitely occurs in the switch and crossing area. Generally, three-point contact doesn’t occur for the new rail profile, which is testified by the wheel-rails interpolation distance and the first order derivative function of the tracing line extreme points. The presented research is not only helpful to optimize the structure of the turnout, but also useful to lower the dynamics of the high speed vehicle-turnout system. 相似文献
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11月18日,山东金亿机械制造有限公司在美丽的海滨城市日照举办了山东省玉米机械化发展与推广研讨会暨2008年商务年会.原计划600多人参加的会议却来了900多人,这在金亿公司是史无前例的,让公司领导及员工忙得不亦乐乎.金亿公司董事长马金英满面春风对记者说:"人气旺盛,一是得益于党的政策好,二是今年金亿公司拥有喜人的表现,小麦机产销1600台,市场占有率由去年的5%提升为15%,玉米机销售1200台,占行业内同类机型首位.同时,金亿产品也是获得政府补贴最多的产品." 相似文献
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张军强 《中国制造业信息化》2007,(18)
西门子中国有限公司的业务结构涉及的行业和领域主要包括:信息通讯、自动化与控制、医疗、照明、能源、交通、金融和房地产等.西门子MES属于西门子自动化与驱动集团,这个业务集团是西门子最古老的集团之一,在中国的业务也发展非常好,产品覆盖各行业客户的自动化需求.自动化与驱动集团分为七个部门,MES隶属于其中的自动化与系统部.整个集团全球有近10万种产品,每个月约有18种新产品问世.自动化与驱动集团将其年销售额的约9%用于研发投资,尤其在工业软件方面很多人都认为自动化是一个硬件设备,但随着现在软件的发展,西门子也提供大量的软件开发. 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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V. V. Stulov 《Journal of Machinery Manufacture and Reliability》2012,41(1):64-66
Similarity criteria describing physical the processes of boiling and condensation of a heat carrier were determined with a
model and natural experiments based on the analysis of dimensions of parameters in the heat exchange problem during cooling
of a crystallizer by heat pipes. Relationships of the geometrical sizes of heat pipes (diameter, length) were estimated. The
novelty of the results is confirmed by patents of invention of catalyst cooling by heat pipes. 相似文献
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The article presents a brief review of the wear models based on the kinetic thermofluctuation approach. The materials were developed using SamGTU sclerometric programming software and a set of instruments developed at Samara Engineering University for assessing the parameters of kinetic thermoactivation for surface fracture deformed by friction. The first obtained results of assessments and the estimated prediction of wear resistance exemplified by tribocouple of the aircraft chassis are presented. 相似文献
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Modern methods of implementation of the rule of positive gradient of mechanical properties are considered; this rule was formulated by I.V. Kragelskii and its application serves to minimize the friction and wear of solids. The given methods include the application of coatings with the method of finishing antifricton abrasion-free treatment; application of new metal-cladding lubricating materials; and creation of a nanostructural state of the surface iron nitride layer by nitriding steel with a positive gradient of hardness normal to the surface. 相似文献
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轮胎单个横沟泵吸噪声计算方法研究 总被引:2,自引:0,他引:2
以205/50R16子午线轮胎为对象,建立具有横向花纹沟槽的有限元法分析模型,利用Abaqus/Explicit进行瞬态滚动分析,得到滚动轮胎单个横沟的体积变化。将其导入Fluent中,利用计算流体力学方法对单个横沟泵吸效益流场进行分析,并结合Lighthill声学类比理论预测横向沟槽的噪声,同时基于涡声理论验证流场与噪声之间的关系。结果表明,单个横沟泵吸噪声第一峰值集中在0.8~2.0 kHz附近,仿真数据与试验结果在趋势上具有一致性;且噪声的声压峰值出现在泵吸状态发生转变的时间段;在时域中的3个噪声峰值出现涡量变化较大的时间段,已确定噪声的变化可由涡量来反映。 相似文献
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Possibility of Nondestructive Testing of Operational Heating of Contact Surfaces of Rolling Bearings
Gorkunov E. S. Tabachnik V. P. Kogan L. Kh. Chernova G. S. Antenorova N. P. 《Russian Journal of Nondestructive Testing》2003,39(6):465-471
The coupling between variation of parameters of nondestructive testing and heating of rolling bearings associated with their operation regime in a helicopter reduction gear is demonstrated. The coercive force method and the eddy-current method of testing outer bearing rings made from ShKh15 steel are considered. 相似文献
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《Mechanism and Machine Theory》1991,26(7):697-709
A method of determining polyhedrons of positioning accuracy of mechanical manipulators is developed. Practical significance of the method is illustrated by numerical examples. Polyhedrons of positioning accuracy for a manipulator of 6-R type are calculated for several positions. 相似文献
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《Mechanical Systems and Signal Processing》2007,21(2):761-779
The paper presents the method of selection of features of diagnostic signals relying on the geometry of observation space. The method presented here uses two criteria of ability to separate (isolate) classes of an object's state: the criterion of average scatters and the original criterion of number of prototypes of classes. The method can be successfully used for initial analysis of input data to a neural network dealing with recognition of patterns and classification of an object's state. It also possible to use the algorithm presented here for determining the prototypes of classes needed for creating the training set for the neural network. 相似文献