第3代轮毂轴承单元轴向游隙影响因素的正交试验

利用正交试验法分析沟位置差、径向游隙、配合过盈量及锁紧力矩等参数对轮毂轴承单元轴向游隙的影响,给出了沟位置差和径向游隙值的控制范围,可为第3代汽车轮毂轴承单元的装配及零配件工艺的优化提供数据支持。     

角接触球轴承凸出量的影响因素分析和组配技术

角接触球轴承在组配过程中,需要经过测量和计算凸出量以确定其修磨量,然后根据修磨量修磨轴承套圈端面,达到组配技术条件要求。本文通过分析角接触球轴承各参数对凸出量的影响程度,在加工过程中通过调整控制磨加工套圈沟位置、沟尺寸,并通过理论计算和智能分选,适当缩小轴承游隙范围,控制沟位置和轴承宽度偏差,缩小单套轴承凸出量值,最终实现少修磨或无修磨万能组配的目的。     

汽车轮毂用带外挡圈圆锥滚子轴承轴向游隙影响因素的分析及对策

通过对汽车轮毂用带挡圆圆锥滚子轴承轴向游隙计算公式的推导及工艺尺寸链的计算，分析了这种轴承的零件中各相关尺寸对其轴向游隙的影响，并从加工的角度提出了保证轴向游隙符合设计要求的具体措施。附图3幅，参考文献1篇。     

三点接触球轴承双半内圈沟道几何参数变化对游隙的影响

讨论了三点接触球轴承双半内圈内部几何参数的关系及轴承游隙的计算方法,并分析了双半内圈接触角、沟曲率半径、偏心量变化对游隙的影响,结果表明:双半内圈相互差对轴向游隙的影响大于对径向游隙的影响;双半内圈主要参数在公差范围内时,接触角对径向游隙、轴向游隙的影响最大,内圈沟曲率半径对径向游隙、轴向游隙的影响最小。     

特大型双排四点接触球轴承承载能力的研究

给出特大型双排四点接触球轴承承载曲线的精确计算方法。绘制其静承载曲面,并对精确静承载曲线及简化静承载曲线进行比较。分析轴承游隙、沟曲率半径系数及原始接触角对静承载曲线的影响。结果表明:随着轴承负游隙绝对值的增大,轴承所能承受的最大倾覆力矩增大,最大轴向力减小。游隙在–0.2~0 mm范围内取值,对轴承承载能力的影响较小。沟曲率半径系数对轴承承载能力影响较大,随着轴承沟曲率半径系数的增大,轴承静承载能力减小。随径向力增加,轴承承载能力随接触角增大先增大后减小。     

一种半柔性轴承的径向游隙控制工艺

分析了一种半柔性汽车转向管柱轴承的结构原理,推导出了该轴承的径向游隙的计算公式,找出影响轴承径向游隙的因素,并对各个因素进行灵敏度分析。用统计方法分析了该轴承游隙的概率分布。提出了基于零游隙轴承宽度测量、连续或分级控制轴承宽度的工艺方法,来提高该轴承的合格率。     

球轴承外沟径尺寸分选仪

向心球轴承在装配前,必须预先将套圈按内沟径、外沟径的尺寸进行分组,然后根据一对内外沟径尺寸选择相应尺寸的钢球进行配套。内沟径、外沟径、钢球三者的分组公差与轴承径向游隙之间的关系如下:     

圆锥滚子轴承内圈挡边的高度测量

圆锥滚子轴承内圈挡边的作用是对滚子运动进行导向,挡边高度尺寸影响轴承的组装轴向游隙,挡边与滚子接触位置是否适合对     

离子溅射WS2涂层对轴承性能的影响

以6308 ETN1深沟球轴承为例,采用射频溅射离子镀膜工艺对其沟道表面进行离子溅射WS2处理,对镀膜前后轴承沟道圆度、沟形误差、表面波纹度、表面粗糙度、沟曲率、成品精度及游隙等的变化进行了测试分析,同时还试验研究了镀膜对轴承润滑性能的影响。     

双列向心对称球面滚子轴承游隙的计算(上)

文内导出了双列对称球面滚子轴承游隙、接触角与各基本尺寸参数的关系式,就该类轴承各基本尺寸偏差对游隙的影响进行了定量分析。附图4幅，表1个。     

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...     

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.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.     

Fractional order nonsingular terminal sliding mode control for flexible spacecraft attitude tracking

This paper investigates a fractional terminal sliding mode control for flexible spacecraft attitude tracking in the presence of inertia uncertainties and extern...     

奥氏体不锈钢表面双辉等离子渗锆的动力学

利用双辉等离子渗金属技术在0Cr18Ni9Ti奥氏体不锈钢表面制备了一层均匀、致密、呈良好冶金结合的渗锆合金层,并对1 060℃下的渗锆动力学进行了研究。结果表明:随着距锆合金层表面距离的增加,锆元素的含量呈梯度递减,扩散系数逐渐减小,而扩散激活能逐步增大;在1 060℃采用双辉等离子技术渗锆时,渗锆合金层表层的空位密度为2.945×(1012~1013)cm-2,与相同温度下采用常规渗金属工艺相比,提高了1~2个数量级。     

气化炉三维扫描测量与数据处理

以德士古气化炉耐火砖的内壁蚀损检测设备为基础,对采集到的点云数据做了进一步处理.通过对数据的筛选和剔除,实现了数据点的平滑降噪细化和精简.然后利用点云对整、网格划分和分色显示等方法,最终完成了内壁腐蚀情况的三维建模.重点讨论了点云数据的预处理及后处理的方法,并根据内壁耐火砖的腐蚀阈值,提出了一种气化炉内壁腐蚀区域的识别与分割方法.对耐火砖的腐蚀分析、气化炉的生产与维修提供了可靠依据,并在工程应用中获得了一致认可.