微型电机轴的绿色加工方法

介绍了一种微型电机轴的绿色加工方法,它突破了微型电机轴传统的加工方法,改车削两端半球面为冷镦,变外圆磨削为冷拉.由于是无切屑加工,节省了材料;由于取消了热处理,节省了能源;由于省去了磨削工序,节约了成本,减轻了对环境的污染,因而实现了微型电机轴的绿色加工.     

双足型直线超声电机的原理分析及结构设计

研制了一种新型直线超声电机,首先对其驱动机理进行了探讨,对定子表面质点椭圆运动的形成进行了分析,结合电机输入电压信号的时序阐明了电机工作模态的激发过程;其次对电机结构进行了设计,确定了振子尺寸,组装了一台直线超声电机.     

液压系统的改造设计研究

对冷床上卸钢系统和四辊轧机开卷机液压系统存在的问题进行了分析,找出了产生问题的原因,并对原液压系统进行了改造,经改造后的系统,减少了油液的泄漏,提高了系统的稳定性,减小了维修强度,降低了维修成本,提高了系统的工作效率.     

芳烃抽提装置真空系统节能降耗改造

介绍了采用装置自产瓦斯为介质的芳烃抽提破真空工艺,节约了氮气消耗,降低了生产成本,保护了溶剂,提高了装置综合经济效益。     

基于单片机的机床动力滑台控制系统的改造

提出了一种新的机床动力滑台控制系统,突破了传统机床动力滑台二次工进最大速度受其一次工进速度的限制,适应了生产需要,提高了工作效率,文中给出了组成图并介绍了其工作原理.     

基于协同应用平台的汽车售后服务系统研究

阐述了国内外汽车制造企业售后服务信息化发展现状,分析了汽车售后服务业务流程,研究了ASP模式的协同应用平台,并根据汽车售后服务的业务特点构建了基于协同应用平台的售后服务系统体系结构。最后,设计了系统的模块,描述了其基本功能,并对系统进行了开发。     

中国农技推广协会四届三次常务理事会在京召开

2007年8月25日,中国农业技术推广协会在北京召开了四届三次常务理事会.在京常务理事和会长、秘书长等参加了会议.陈耀邦会长出席会议并作了重要讲话,夏敬源常务副会长主持了会议.会议传达贯彻了全国农业厅局长座谈会和全国基层农技推广体系改革和建设会议精神,总结交流了上半年工作进展,研究部署了下半年工作重点,讨论决定了会员管理、理事增补等事宜.     

控制焊接飞溅物 提高液压油箱清洁度

阐述了液压油箱的结构和制造工艺。通过改进结构,方便了焊接操作;通过细化工艺,确定了焊接规范,从而控制了飞溅,减少了油箱内的清理量,提高了清洁度。     

CRM的2003

又一年过去了，对于CRM已是第四年了，这一年似乎特别的冷默与寂静，少了许多“热闹”，却多了许多“变化”；少了许多“概念”，多了许多“方案”；少了许多“专家”，多了许多“供应商”；……     

基于有限元分析方法的高速电主轴热态特性研究

介绍了高速电主轴的特点,分析了高速电主轴单元的热变形机理与散热机制。建立了某型高速电主轴热态特性有限元分析模型,利用ANSYS进行了稳态／瞬态温度场及热-结构耦合场分析,并利用分布加载瞬态热分析模拟了机床一天中的实际工作情况,得到了电主轴的温度场变化情况,为有效控制电主轴的温升提供了理论依据。在分析结果的基础上,提出了改善电主轴热态特性的措施,为电主轴冷却结构设计提供了参考。     

A procedure for making phosphor viewing screens for the transmission electron microscope

A technique is described for preparing uniform, durable phosphor layers for viewing screens suitable for the transmission electron microscope; a settling procedure is used. The example described here is for a high-voltage instrument, but with adjustment of the coating density, the technique should be equally suitable for screen preparation for transmission electron microscopes that operate at lower acceleration voltages.     

基于Web的机械设计答疑系统的研究与开发

利用JavaScript和VBScript编写ASP程序 ,利用SQL和ODBC技术建立网络数据库 ,利用流媒体技术实现动画和视频的网上快速播放 ,利用虚拟现实技术实现三维图形的交互式实时浏览 ,开发了一套基于Web的机械设计答疑系统。该系统适用于绝大部分机械设计人员 ,尤其适用于广大初学者。     

A Surface Area Calculation and CAPP System for Non-Axisymmetric Deep Drawing Products

In this paper a surface area calculation for non-axisymmetric deep drawing products of elliptical shape was constructed for the design of blank shapes of deep drawing products by using an AutoLISP function in AutoCAD software. A computer-aided process planning (CAPP) system for rotationally symmetric deep drawing products has been developed. In this study, a CAPP system for non-axisymmetric deep drawing products of elliptical shape was constructed using process sequence design. The system developed consists of four modules. The first is the recognition of shape module for recognising non-axisymmetric products. The second is a 3D modelling module for calculating the surface area for non-axisymmetric products. The third is a blank design module for creating an oval-shaped blank with an identical surface area. The fourth is a process planning module based on production rules that play the most important role in an expert system for manufacturing. The production rules are generated and upgraded by interviewing field engineers. The drawing coefficient, the punch and die radii for elliptical shape products are considered as the main design parameters. The suitability of this system was verified by applying it to a real deep drawing product. This surface area calculation and CAPP system should be very useful for reducing the lead-time for manufacturing and for improving the accuracy of products.     

汽车发动机系滚动轴承润滑脂动态可靠性测试及评价

介绍了汽车发动机系滚动轴承润滑脂动态可靠性的测试及评价方法,包括SKF Emcor润滑脂动态抗腐蚀测试,FAG FE8润滑脂动态抗极压和磨损性能测试以及FAG FE9润滑脂动态润滑寿命测试,对正确选用润滑脂以及汽车发动机系滚动轴承可靠度设计等提供参考.     

A handheld support system to facilitate stereological measurements and mapping of branching structures

BranchSampler is a system for computer-assisted manual stereology written for handheld devices running Windows CE. The system has been designed specifically to streamline data collection and optimize sampling of tree-like branching structures, with particular aims of reducing user errors, saving time, and saving data in formats suited for further analysis in other software, for example, a spreadsheet. The system can be applied in a wide range of applications, from biomedical science to agriculture and horticulture. It can be applied for sampling nested generations of lung bronchioles and renal arterioles or for collection and optimizing sampling of crops for precision agriculture. Although the system has been designed specifically for sampling branching structures, it is sufficiently flexible to be used for other applications involving nested stereological designs. We describe the system specifications, software and Graphical User Interface development, functionality and application of the handheld system using four examples: (a) sampling monkey lung bronchioles for estimation of diameter and wall thickness (b) sampling rat kidney for estimating number of arteries and arterioles in a specific generation (c) mapping fruit (apple) tree yield in an orchard and (d) estimating the total leaf surface area of chrysanthemum plants in a greenhouse.     

采用ADAMS的轮式小型甘蔗收割机转向和越障性能仿真研究

借助ADAMS-View软件建立一个轮式小型甘蔗收割机的样机模型,并对样机模型行走转向和越障性能进行仿真,得到样机行走转向和越障性能的仿真曲线,为轮式小型甘蔗收割机行走机构的研制提供一些依据.     

Qualitative criteria for dynamic buckling of imperfection sensitive nonconservative systems

A qualitative dynamic buckling analysis of imperfection-sensitive non-conservative dissipative systems under path-dependent loading in regions of divergence is presented. Despite the lack of potential for this type of loading a total energy-balance equation allows us to establish a sufficient criterion for dynamic buckling, the counterpart of that valid for potential systems. Moreover, using energy and geometrical considerations for the channel of motion, one can obtain for a 2-DOF model dynamic buckling loads (DBLs) which are practically exact for vanishing but non-zero damping and very accurate for non-zero damping. Numerical results show the efficiency and reliability of the proposed qualitative analysis.     

Controlled serial grinding for high-resolution three-dimensional reconstruction

This work reports an improved preparation procedure for acquiring SEM images for three‐dimensional (3D) reconstruction. The images are acquired consecutively after serial grinding and polishing. Ugelstad beads are used as landmarks for registration purposes and for determining the thickness of the abraded sections. An estimation of the bead sizes necessary for suitable thickness quantification at the corresponding spatial resolution and uncertainty is given. Shape‐based interpolation is used for filling the gaps between the cross‐sections. An indication of the distance between cross‐sections necessary for good interpolation is also given. An example of a 3D reconstructed paper volume is presented. The method is suitable for preparation of fibre and paper as well as other materials.     

Approximate Formula for the Contact between Truncated Surfaces and Frictional Characteristics of a Journal Bearing in Mixed Lubrication

This paper presents an approximate formula for the contact of a non‐Gaussian distribution of truncated surfaces, which is useful for mixed lubrication theory, and gives a method for the determination of the truncation parameters in this formula from a measured roughness profile. Using this approximate formula for a contact, the approximate formula for the friction coefficient of a journal bearing in mixed lubrication, which was previously proposed by the authors, is modified for truncated surfaces, and the frictional characteristics are demonstrated for various parameters of truncated roughness using the modified formula.     

Flexible tools for specifying design variation

This paper describes flexible tools for specifying design variations that are based on non-uniform profile tolerance definitions. These tools specify bounds of design performance that can be used for negotiation among engineers in a collaborative design process. These specification methods allow for the capture of many different design functions that are not easily described with current tool designs. In addition, these specification methods lend themselves to efficient verification methods. Profile tolerance definitions provide the most general variation controls for complex mechanical surfaces. Common design practices and engineering standards for profile tolerances exhibit many weaknesses and limitations. We present a rationale for a complete specification approach using B-splines [1, 2] for profile tolerances, and illustrate the approach with examples. B-splines can be used to specify both uniform and non-uniform profile tolerance boundaries. Subsequently, algorithms for the evaluation of actual feature deviations and reporting methodologies for such tolerance zones are presented.