LJ078A深沟球轴承浪型保持架球兜节圆直径及球兜深度测量仪

LJ078A深沟球轴承浪型保持架兜孔中心圆直径及兜孔深度测量仪采用比较测量法，可对深沟球轴承冲压浪型保持架主参数进行测量和控制，提高了保持架模具制造精度，有效地控制保持架的产品质量。通过实践验证，该仪器测量精度完全能够满足生产需要。     

Deterministic Friction Model of a Rough Surface Sliding Against a Flat Layered Surface

In this paper, a layered surface is modeled like a solid that has effective mechanical properties (E _eff(), _eff() and H _eff()) as a function of indentation depth () and the rough surface is modeled as a population of spherically shaped asperities with different radii and heights (not necessarily Gaussian distributed). The contact behavior and the resistant to motion experienced by each asperity is analyzed locally and summarized as the total friction force based on the adhesion and ploughing mechanisms. The present model extends the capability of Halling's model to predict friction of layered surfaces. With this model, one is able to predict the friction of soft layer on a hard substrate and hard layer on a soft substrate in contact with a rough counter surface.     

与阿基米德螺旋平面齿轮啮合的弧齿线圆柱齿轮齿形研究

针对文献［１］所提出的一种新型弧齿线圆柱齿轮传动,在对该种齿轮副建立数学模型的基础上,对弧齿线圆柱齿轮的齿形进行了分析和计算,为进一步研究其传动性能打下了基础。     

球磨机大齿轮磨损后的变位修复

主要对水泥厂球磨机主传动系统中的标准直齿圆柱齿轮磨损后进行变位修复进行论述。提出了修复方案,确定了变位系数,并对齿轮的根切、齿顶变尖、重合度、齿根弯曲疲劳强度和齿面接触疲劳强度、相对滑动率、过渡曲线有无干涉现象做出了详细的检验。对水泥和矿山机械中大齿轮的变位修复具有一定的指导意义。     

一种基于物理造型的球体弹性碰撞模拟算法

虚拟环境是一种逼真的视、听、觉一体化的计算机生成环境 ,虚物实化的目标是不仅要使虚拟环境下的虚拟物体在外观上有逼真感 ,而且在行为 (运动与变形 )上符合物理学规律。本文从较简单的弹性小球的平面碰撞入手 ,建立了一种解决纯弹性碰撞问题的实践方法 ,实现了虚物实化的目标。该算法对于物理造型的进一步研究有一定的理论价值和实用意义。     

A Method for Determining the Convergence under Contact between a Sphere and a Flat Surface of a Workpiece under Small Loads

A unified analytical dependence for determining the full convergence at the contact between the sphere and flat surface of has been obtained and experimentally confirmed. It is valid both under the conditions of purely elastic deformation and elastoplastic deformation.     

硬密封球阀耐冲蚀陶瓷涂层研究

利用多功能超音速火焰喷涂技术，在金属硬密封球阀的阀芯上制备了WC-12Co金属陶瓷涂层，用于提高球阀的耐冲蚀磨损性能。试验表明，涂层机械力学性能好，与基体结合强度超过70MPa，孔隙率小于2％，硬度超过HV1000，耐冲蚀磨损性能比基体提高5倍以上，有效地提高了球阀的使用寿命和密封可靠性。     

滚动轴承微动磨损的影响因素

在油脂润滑条件下 ,对深沟球轴承在不同的摆动角度和不同的负荷下的微动磨损进行了研究 ,其结果 ,轴的摆动角度对磨损有极大的影响 ,虽然摆动角度小于 1°时磨损速度较低 ,但当摆动角度超过 1°后磨损急剧增大。这种倾向表现出犹如在重载荷时那么显著。这一现象可以用差动滑动和切向力滑动而求出的τδ的大小及其分布形态加以说明     

Software for Simulating the Surface Wear of Tools

Russian Engineering Research - Software for recording machining tracks in abrasive lapping is described. The software permits prediction of the shape and magnitude of the tool’s surface wear...     

润滑剂中固体污染物对轴承振动和磨损的影响

润滑剂中固体夹杂物所致的表面损伤已经成为轴承失效的主要原因.介绍了试验及检测方法.分析了清洁油及污染油中试验时轴承的振动、轴承磨损和污染颗粒大小对振动的影响等,并提出了防止润滑剂污染的措施.     

E36高强度球扁钢的静态再结晶

在热模拟试验机上利用双道次压缩方法研究了E36高强度球扁钢在不同温度下两次变形弛豫的静态再结晶行为。结果表明:E36钢在900℃以上变形时,再结晶过程较快,在30～50 s内均已完成完全再结晶;在900℃时,再结晶过程明显减慢,弛豫1 000 s再结晶体积分数还不到50%,再结晶孕育期增至40 s左右;850℃时再结晶已非常困难,弛豫4 000 s后由于奥氏体静态再结晶数量多,最终组织拉长的贝氏体晶粒较驰豫1 000 s的少,大部分是由再结晶后等轴奥氏体晶粒转变而来的细小、均匀的贝氏体晶粒,沿晶界有较多针状铁素体晶粒。     

求相贯线极限点的球面法

本文提出利用辅助球面法 ,准确地确定圆柱与圆锥 ,圆球与圆锥相贯线极限点的方法。     

基于磨粒表面信息的磨损表面特征评估

建立了基于磨粒表面信息的磨损表面评估方法。首先选择合理的磨粒和磨损表面特征参数，通过识别磨粒类型，获得磨损过程中具有典型性和代表性的磨粒类型，然后选取这些具有代表性的磨粒类型，得到磨粒的表面特征向量，进而来研究磨损表面和磨粒表面的映射关系，实现基于磨粒表面信息的磨损表面特征评估。实例表明，根据磨粒表面特征评估磨损表面特征是可行的。     

一种新型钢球表面检测方法的分析与系统实现

钢球作为常用的球轴承滚动体,其表面质量直接影响轴承的性能及寿命。目前已研制出的钢球表面缺陷检测装置展开机构结构复杂,不适用于大批量检测。基于一种双图像传感器的球面全展开方法,分析了在球列状态下球面完全展开所需要满足的参数条件。搭建系统进行实验,实验结果表明,该系统利用双传感器同时分别对每粒钢球进行5次采像就能够对钢球表面进行精确有效的高速检测与分选,漏检率低,检测速度可达到14 400粒/h,具有广泛的应用前景。     

四点接触球轴承桃形沟道的切入磨削

四点接触球轴承桃形沟道在切入式磨床上，通过调整砂轮修整器与砂轮的相对位置改变砂轮圆弧偏心量，形成桃形一次切入磨削成桃形沟道。     

A New Form of Rolling Contact Damage in Grease-Lubricated,Deep-Groove Ball Bearings

A new form of rolling contact damage was discovered in the fatigue tests of series 6206 deep groove ball bearings under pure radial load with grease lubrication. The appearance of the damage reveals a few cracks at right angles to the rolling direction of the ball, along with the formation of a dent about 20 μ m deep in the raceway surface. This is found to occur only on the stationary outer ring raceway and the ball surface and is distributed widely within the load zone. Furthermore, under the raceway surface several cracks propagating into the substrate at an angle of about 60-80 degrees relative to the raceway surface are observed not only under the damage site but also in other nearby locations. Only the cracks at the damage position open up to the surface. The grease used for the test contained a lithium complex thickener with mineral oil as the base oil with a kinematic viscosity of 141 mm²/s at 40°C. On the test bearings two pure radial load levels of 9.14 and 12.13 kN were applied. In order to prevent the occurrence of seizure at each load, the speed of the inner ring of the test bearing was maintained at 1800-2500 min^{? 1} and 600-800 min^{? 1}, respectively, to keep the outer ring circumference temperature below 65°C. It is suggested that the damage is caused by metal-to-metal contacts due to lubricant starvation under grease lubrication and to a decrease in oil film thickness due to local increases in temperature.     

Exoelectron Emission for the Study of Surface Fatigue Wear

An apparatus has been constructed for studying exoelectron emission from steel bearing balls which have been run in a Barwell four-ball surface fatigue wear tester. The test ball is periodically removed from the tester, cleaned to remove its oil film, transferred to a vacuum chamber, and illuminated by ultraviolet light. The emitted exoelectrons originating at new surface area generated on the ball during fatigue testing are detected by an electron multiplier. By rotating the ball and measuring the exoelectron emission as a function of position, the source or sources of the emission can be localized. The resolution of the research apparatus is presently limited to 0.27 mm, the width of the scanning spot. Exoelectron emission decay results indicate a relatively slow drop in emission with time. Preliminary results indicate that the fatigue failure occurs at one of several sites which have given enhanced electron emission.     

A Combined Molecular Dynamics and Finite Element Analysis of Contact and Adhesion of a Rough Sphere and a Flat Surface

A combined molecular dynamics and finite element model and simulation of contact and adhesion between a rough sphere and a flat surface has been developed. This model uses the results of molecular dynamics (MD) simulations, obtained using an embedded atom potential, of a nanoscale Ru-Ru asperity contact. A continuum finite element model of an elastic–plastic microscale Ru-Ru contact bump is then created. In this model, the surface roughness is represented by a system of nanoscale asperities, each of which is represented by a nonlinear hysteretic force vs. distance relationship. The nonlinear hysteretic character of these relations is determined from curve-fits of the MD results. Load vs. interference and contact area vs. interference are determined using this two-scale model for loading and unloading. Comparisons with a single-scale continuum model show that the effect of the nanoscale asperities is to reduce both the adhesion and the real area of contact. The choice of Ru as the material for this work is due to its relevance in microswitches.     

钢球表面质量评价系统

介绍了钢球表面质量检测实验装置中展开轮的工作原理 ,提出了钢球表面缺陷自动检测与识别的方法 ,给出了基于图象纹理特征的钢球振动值预测模型 ,并通过仿真实验表明 :该模型的拟合精度较高。附图 1 0幅 ,参考文献 5篇。     

针对机械磨损过程的功能检测模型

在以可靠性为中心的维修分析中,通常对由机械磨损引起的故障模式采用功能检测策略加以预防,而制定此类问题的功能检测策略时需确定下列参数：１．潜在故障状态（用磨损量表示）,检测时如果发现产品磨损量达到或超过该状态,应当予以更换;２．检测的间隔发首次检测间隔期与重复间隔期。借助于维修延迟时间的概念并假设磨损过程服从Ｗｉｅｎｅｒ过程,建立基于风险,可用度与费用的功能检测模型,用于确定上述检测参数。