深沟球轴承保持架铆合方法的优化

针对深沟球轴承保持架铆钉铆合后出现铆钉头断裂、脱落的问题,提出采用双面热铆合方法对保持架进行铆合。具体方法为:采用无钉头铆钉和双工装进行铆合,设计专用工装保证铆合前铆钉在保持架两端面凸出高度一致,在此基础上进行第一面铆合,完成一面铆合后,翻面选用原铆合胎具进行第二面铆合。试验证明该铆合方法合理可行。     

深沟球轴承保持架铝铆钉双面压铆工艺

针对深沟球轴承用车制实体保持架采用LC3材质铝铆钉单面铆合时易出现原铆钉帽脱落的问题,通过分析铝铆钉的铆合变形机理,提出一种保持架铝铆钉双面铆合工艺。以某型深沟球轴承为例开展铝铆钉双面铆合试验,结果表明：与单面铆合相比,双面铆合时铆钉帽直径散差和高度散差更小,保持架宽度减小量更小;铆钉帽整体组织与铆钉杆组织相同,且未出现环状“V”形缺口。实际加工及耐久性试验进一步验证了双面铆合工艺的有效性,满足了工艺需求。     

实体双半保持架轴承电铆合工艺改进

介绍航空传动系统球轴承用实体双半保持架装配铆合的难点,分析传统单面电铆装配工艺存在的问题,通过胎具的改进设计和铆合工艺流程的优化,实现了保持架的双面电铆合,铆合后铆钉头与保持架端面贴合紧密,铆钉抗断裂能力明显增强,提高了轴承的装配质量。     

关于铆钉长度的探讨

铆钉长度L（见图1）的大小对轴承保持架的铆合质量有着重要的影响。铆合质量问题通常有余料挤出（俗称双眼皮）、铆钉歪斜、保持架铆合错位等。这都是铆钉长度L不合适所致。所以，有必要对铆钉长度L的合理长度进行探讨。图2所示为铆合后的铆钉，形成了SR’半球体和保持架铆钉孔内的激粗变形。SR’半球形体积设为h，则式中d——铆钉头高度H的最大加公差保持架铆钉孔内部铆钉被缴粗产生的体积增量设为D’。，则式中t。——铆钉孔公称直径。m。x——铆钉孔最大加公差d－——铆钉杆直径公称尺寸」——铆钉杆直径最小减公差S——保持架钢板厚…     

圆柱滚子轴承摆辗铆合方法

圆柱滚子轴承装配时采用摆辗铆合方法,可保证铆合质量,可克服原压力机铆合时铆钉杆被镦粗和保持架变形等缺陷。文中介绍了摆辗铆合的若干措施,附图5幅。     

方铆头车制实体保持架铆钉头相关部位的设计

圆柱滚子轴承方铆头车削实体保持架铆钉头相关部位尺寸直接影响轴承的装配和铆合质量。介绍了铆钉头相关部位的设计步骤和计算方法。附图 5幅 ,表 1个。     

中大型轴承保持架电铆机改造

针对原中大型轴承保持架电铆机存在的压力不能调整、铆钉铆合质量难以保证以及工人劳动强度大等问题，通过改进气缸和工作台的设计，用气缸代替压缩弹簧，实现了铆钉电加热时的压力可调，提高了铆合质量，降低了工人劳动强度。     

浪形保持架铆合的改进

浪形保持架在装配时要经过铆合，使两半保持架牢固地铆接起来起到保持作用。过去在组装轴承时，需在装球后将球拨匀，扣上两半保持架，然后将铆钉一个个地插入保持架的铆钉孔中，扣上铆模，送到冲床中冲压，效率低。又因过去用的半圆头铆钉，在铆模中垂直度没有保证，容易造成铆歪、铆偏及漏铆钉等不良情况。     

铆接工具的改进

我公司许多产品采用半圆头空(?)钉进行铆接,由于铆接工具过于简单,常常造成铆接失效。拆除铆钉及补铆耗费大量工时并影响产品质量。本人针对使用中存在的问题,重新设计了一套铆接工具,取得了良好效果。 1.铆接时经常出现的问题 1)铆钉放置歪斜,铆头下压时不能对准铆钉孔而压偏(见图1)。由于铆钉孔深有限,不能加长铆头的导向部分,以引导及纠正铆钉位置。常用的气动压机及冲床,工作时都是压头快速下行,无法实现低速下行到铆钉对中后再加压铆合,致使铆钉压偏而损坏。     

浪形保持架的冷挤铆合工艺

我厂试验了一种以冷挤空芯铆钉法铆合浪形保持架的工艺,该工艺的特点是,操作方便,省掉了实芯铆钉和装插铆钉的手工劳     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.