高精度蜗杆和其他螺旋齿形采用CNC蜗杆和螺纹磨床的经济性生产

1.引言很久以来,成形磨削法一直用于蜗杆和螺纹状工件的磨齿。为了使这种高效工艺能提供所希望的经济性,现代化蜗杆和螺纹磨床必须满足有关砂轮的准确成形,生产时间短、高效金属磨削、调整更换时间和非生产肘间少等方面的要求。此外,在某些应用领域内(例如机床、升降机驱动系统等中的定位传动装置),在齿形、导程和齿距中取得高精度是必要的。     

ZC1蜗杆磨削用CNC砂轮修整器设计

ZC1型蜗杆因具有良好的传动性能和综合效果而备受关注,磨削加工是提高传动性能的关键,磨削用砂轮的修型方法直接影响其加工精度.根据ZC1蜗杆磨削的数学模型,提出了一种专用的砂轮修整器结构模型,设计了一种CNC砂轮修整器的系统结构,为提高ZC1蜗杆的磨削加工精度和效率提供一种新途径.     

ZC1蜗杆精密磨削加工

基于成形砂轮对工件进行磨削加工的原理,应用空间啮合理论对ZC1蜗杆磨削过程进行理论推导,得出了唔合线方程和砂轮轴向截形的数学模型,利用MATLAB软件计算出砂轮的轴截形并利用此截形数据在配有CNC砂轮修整器的数控螺纹磨床上对砂轮进行修型,用修型好的砂轮磨削工件从而实现对蜗杆的精密加工.     

精密、超精密圆柱渐开线齿轮的加工方法

超精密齿轮的制造质量反映出了一个国家制造业的发展水平。分析比较了锥形砂轮磨齿、蝶形砂轮磨齿、大平面砂轮磨齿、蜗杆砂轮磨齿和成形砂轮磨齿的工作原理及当前国内外精密、超精密圆柱渐开线齿轮的加工现状,探讨了ISO1328-1997标准中2级以上精度超精密齿轮的加工。并论证了国产大平面砂轮磨齿机Y7125由于具有结构简单、传动链刚度高、具有较高的磨齿精度以及较大的改装空间等优点,通过一系列的研究工作,有可能把它改装精化成磨削超精密圆柱渐开线齿轮的加工母机,实现2到1级精度超精密齿轮的加工。     

基于虚拟中心距原理的鼓形蜗杆砂轮成形修整方法

为了在普通蜗杆砂轮磨齿机上磨削面齿轮，提出在普通蜗杆砂轮磨齿机上修整面齿轮磨削用鼓形蜗杆砂轮的方法。通过母线螺旋扫掠的方式将面齿轮插齿刀向蜗杆砂轮演变，给出面齿轮磨削用鼓形蜗杆砂轮的演变计算方法，建立鼓形蜗杆砂轮的型面方程；分析鼓形蜗杆砂轮型面特征和磨齿机修整机构的运动特性，提出基于虚拟中心距加工原理的鼓形蜗杆砂轮成形修整方法，将砂轮的偏心摆动作为修整冲程运动，通过四轴联动方式修整鼓形蜗杆砂轮螺旋面；最后采用VERICUT对所提修整方法进行仿真验证，表明采用该方法在普通蜗杆砂轮磨齿机上能够有效修整鼓形蜗杆砂轮。     

基于VERICUT的ZC1蜗杆磨削仿真技术

基于磨削啮合原理建立ZC1蜗杆磨削过程的数学模型。根据空间坐标转换与啮合原理推导出砂轮轴向截形方程,借助MATLAB软件计算砂轮截形,生成其离散点数据,并在SolidWorks平台下建立砂轮与磨削机床几何模型。在VERICUT平台中编制数控程序进行仿真磨削加工,提取蜗杆截形,并测量虚拟误差,分析了磨削过程中当交错角变化时蜗杆截形的误差变化趋势,为ZC1蜗杆的精密磨削加工提供新思路。     

蜗杆砂轮磨齿工艺

提高磨齿工艺的生产能力是齿轮加工技术的一项重大课题。西德Aachen工业大学教授、工学博士W.Konig发表了一项旨在提高磨齿生产能力和磨削质量的蜗杆砂轮连续展成磨齿工艺的研究报告,通过试验比较得出的数据,颇有参考价值。一、概述蜗杆砂轮连续展成磨齿法采用带有精确齿条齿形的蜗杆砂轮(图1)和被磨齿轮在一个同步电机带动下,通过砂轮对齿轮的滚磨产生渐开线齿形和工件在拖板带动下作上下移动来完成的。加工时需要调整的数据有:轴     

大型数控成形磨齿齿面误差控制研究综述

相比于蜗杆砂轮磨齿,成形磨齿适用于大直径大模数齿轮的高效磨削,但也存在磨削精度控制难、精密修形难、在机精密检测难等问题.综述成形磨齿齿面误差控制方面的国内外研究和发展,从砂轮修整系统误差、齿轮磨削系统误差以及在机检测系统误差3个误差源方面对近些年国内外研究成果和存在的问题展开讨论,提出了需要进一步深入研究的方向和内容:...     

面齿轮蜗杆砂轮的成形修整工艺误差建模及补偿方法

蜗杆砂轮磨削是面齿轮的精加工工艺,蜗杆砂轮修整精度直接影响面齿轮磨削精度。本文分析了修整工艺误差对磨削齿面误差的影响规律,并提出了一种面齿轮蜗杆砂轮的成形修整工艺误差建模及补偿方法。首先,建立面齿轮蜗杆砂轮的数学模型,分析面齿轮蜗杆砂轮的成形修整原理,提出利用圆柱齿轮磨齿机的多轴耦合联动实现面齿轮蜗杆砂轮的成形修整。其次,将修整工艺误差分为轴向位置和径向位置误差,分析轴向位置和径向位置误差对磨削齿面误差的影响规律,提出成形修整工艺误差的补偿方法。最后,进行蜗杆砂轮补偿修整、面齿轮磨削加工及测量实验,实验表明：左齿面齿形误差由补偿前51.9μm到补偿后7.9μm,右齿面齿形误差由补偿前35.3μm到补偿后17.6μm,验证了误差补偿方法的有效性。     

ZC3蜗杆成型磨削的影响

ZC3蜗杆的加工质量主要取决于砂轮修整质量,本文根据ZC3蜗杆的成型原理,计算ZC3蜗杆轴向截形,从而推导出砂轮的轴向截形,利用vs2008软件,研究对ZC3蜗杆成型磨削的影响因素。     

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...     

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.     

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.     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

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.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.