一胎双活磨削新工艺

一胎双活就是增加无心夹具的支点,做到一次装卡磨削两个工件。这种新工艺不仅可以用于磨削无挡边的圆柱外圈滚道,双挡边的圆柱外圈滚道,而且还可用于磨削圆锥外圈滚道。采用单极磁力无心夹具,它是通过空气形成磁回路,磁通密度大,可满足双支点支承吸住两个工件,如利用无心夹具双支点一次装卡两个无挡边的圆柱外圈,而后磨削成形。磨双挡边的圆柱外圈滚道与磨无挡边的一样,只是在两片砂轮中间增加一个垫圈,其厚度应是一个挡边宽度的二倍。还阐述了同时加工两个圆锥外圈滚道的方法。     

2000型、32000型轴承滚道尺寸控制

２０００型、３２０００型轴承滚道尺寸控制瓦房店轴承厂（１１６３００）杨玉叙词：圆柱滚子轴承，滚道，尺寸公差２０００型圆柱滚子轴承外圈无挡边，内圈双挡边；３２０００型圆柱滚子轴承外圈双挡边，内圈无挡边。在加工这两种类型轴承内、外圈挡边时，按设计图纸要求...     

耐热钢无油沟宽挡边圆柱滚子轴承外圈滚道与挡边的磨削加工

耐热钢无油沟宽挡边(≥3 mm)圆柱滚子轴承外圈使用的耐热钢材料黏性大、硬度高,采用复合磨削方法磨削外滚道与挡边时,由于挡边宽,磨削热难以散发,挡边易产生磨削烧伤。为解决这一问题,采用了新的磨削工艺:单独磨削滚道后在切入磨机床上磨削挡边,先横向进给,然后纵向进给,依靠砂轮的自然脱落形成滚道与挡边的过渡圆弧。     

推力圆锥滚子轴承车工外圈滚道和挡边的加工与测量

详细介绍推力圆锥滚子轴承外圈滚道和挡边的车加工、测量方法。     

圆柱滚子轴承外圈滚道和挡边的复合磨削

通过对内圆磨床砂轮修整器的改造,实现了圆柱滚子轴承外圈两挡边和滚道的复合磨削,有效提高了加工效率和加工质量.     

NJ系列圆柱滚子轴承双挡边超精工艺改进

介绍NJ系列圆柱滚子轴承外圈双挡边目前的加工方法,分析上、下挡边出现靠近滚道侧超精不到边原因,通过改变油石位置、接触形状,调整油石振荡幅度,保证了双挡边的超精质量。     

3MZ141OSA全自动外沟磨床砂轮修整器改造

3MZl410SA全自动外沟磨床是磨削球轴承外圈沟道的的专用设备,在节约资金的基础上对该设备进行了改造,使其能够同时磨削短圆柱滚子轴承外圈滚道及两挡边。     

空心圆柱滚子轴承

空心圆柱滚子轴承结构很简单,见图1。它由带挡边的外圈、空心圆柱滚子及轴承内圈组成(也可以是内圈带挡边而外圈无挡边)。内圈滚道直径比装在外圈滚道的滚子内复圆直径要大些。因此轴承装置后空心滚子受压缩而略呈椭圆形。空心滚子同内外滚道间产生了相互作用力——预负荷。轴承回转时,空心滚子在预负荷作用下紧压在内外滚道上作无滑动的纯滚动。这种轴承结构上的特点是:     

国外车削圆锥滚子轴承外圈用的高效率刀具

近年来,国外为提高圆锥滚子轴承外圈的车削加工效率,在刀具方面曾进行了一些试验,有的改进车刀刀片材料,有的改变车刀的结构形状,从材料与结构两方面改进以提高车削效率。 多点组合刀具 捷克斯洛伐克在研究提高大型圆锥滚子轴承外圈的加工,特别是提高内滚道车加工的效率时,设计了一种能一次车成滚道的多点组合刀具。 结构及几何参数:如图1所示,组合刀具有一个带锥柄的圆锥形刀体A,40把硬质合金车刀B分成五组,每组车刀与刀体轴线成75°螺旋形排列在刀体上,螺距不能调节,但排列的角度可在3°～5°内变动,这样排列的好处是可消除被加工材料中因组织不均而出现个别硬点时的振动影响,因而使工件得到较高的几何形状精度和加工表面光洁度。     

轻窄系列双挡边圆柱滚子轴承套圈车工工艺改进

轻窄系列双挡边圆柱滚子轴承套圈的特点是壁厚薄、宽度窄。双挡边套圈滚道在数控机床上需对接加工,因为棱圆度的影响,滚道上常会出现一道高低不平的接口。通过改变车加工工艺,使接口问题得以解决。     

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...     

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.     

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。     

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...     

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。     

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。     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

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.     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

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...