浮动式反向器回珠槽在牧野105型数控铣床上的加工方法

<正> 在内循环滚珠丝杠副中,反向器回珠槽的作用是沟通滚道中滚珠链的回路,使滚珠链得以封闭并能循环。回珠槽曲线的加工质量,将直接影响滚珠丝杠副的传动精度、运动平稳性及其传动效率等为了保证内循环滚珠丝杠的各项质量指标,多年来我厂加工反向器回珠槽曲线,一直是在由日本引进的牧野105型数控铣床上加工。现将图一所示浮动式反向器中回珠槽曲线的加工步骤与方法介绍如下     

新型滚珠丝杠副端塞式反向器的优化设计与分析

滚珠与反向器的碰撞与摩擦,是导致滚珠丝杠副摩擦力矩产生波动的一个重要原因,也是导致反向器失效的主要原因。因此需要对反向器回珠曲线进行优化,降低滚珠与反向器的碰撞力,提高反向器的流畅性。提出了一种新型多段圆弧端塞式反向器的设计思路与优化方法。采用Matlab进行有约束的非线性优化,得到优化后回珠曲线,得到优化后反向器的Pro/E三维模型,利用ADAMS仿真软件对优化前和优化后的反向器进行动力学分析,仿真结果表明优化后新型端塞式反向器能有效的降低滚珠与反向器的碰撞力,并使碰撞力更加均匀,有利于提高反向器的流畅性。     

基于ADAMS的滚珠丝杠副滚珠循环系统的动态仿真

研究滚珠丝杠副的滚珠循环系统的回珠曲线的理论模型,并在Pro/E中建立反向器的三维模型.使用接口软件向ADAMS中输入丝杠的装配模型.根据赫兹接触理论和冲击函数模型,在多体动态软件ADAMS建立动态仿真模型,得出滚球在运转过程中进出反向器的能量、冲击力的变化情况,为回珠曲线的优化提供指导性依据.     

内循环滚珠丝杠副反向器优化设计与仿真

针对内循环滚珠丝杠副中滚珠与反向器之间碰撞和摩擦易导致反向器失效的问题,以减小滚珠与反向器之间接触碰撞力和摩擦力矩为目标,正弦曲线和五次抛物曲线叠加权重比系数为设计变量,对现有反向器回珠曲线进行优化计算。在获得最优回珠曲线后,建立三维模型并进行多体动力学仿真分析。仿真结果表明:优化后的反向器回珠曲线有效的降低了滚珠与反向器之间的碰撞力和摩擦力矩,滚珠运行更加流畅,滚珠丝杠副的动态性能得到明显改善。     

滚珠丝杠新型回珠槽曲线设计与分析

本文对内循环滚珠丝杠副反向器提出了新型回珠槽曲线（五次抛物线型）的设计方法。这种方法计算简单，并具有与正弦曲线相近的动态特性，即曲线具有“二阶连续性”，同时还可改变反向角来调节反向滚珠数量，保证参加工作的滚珠数量，提高接触刚性和承载能力。     

滚珠丝杠副的滚珠返回装置

滚珠丝杠副在运动过程中,滚珠沿丝杠和螺帽的圆弧滚道作连续的循环运动。把运动滚珠的输入和输出连接起来,并形成一个闭合循环回路的装置,就称为滚珠返回装置。一、返回装置的型式和特点滚珠返回装置可以分为两大类,即:内循环和外循环。目前,内循环只有反向器一种(见图1);外循环主要有套筒-回珠槽(盖板-回珠槽)型、端盖-回珠     

端塞式滚珠丝杠副系统动力学仿真与分析

根据赫兹接触理论,对端塞式滚珠丝杠副系统的接触碰撞进行了分析,通过ADAMS宏命令建立端塞式滚珠丝杠副系统动力学仿真系统,利用仿真系统对端塞式滚珠丝杠反向器进行仿真实验。实验结果为改善滚珠丝杠系统的流畅性与摩擦力矩性能提供技术支持,提高了设计品质,对研究滚珠丝杠副摩擦力矩的产生及变化,也有一定的参考价值。在此基础上可以建立多种型号的滚珠丝杠副仿真系统,为实际生产过程提供了理论指导。     

内循环滚珠丝杠副反向器理想轨迹的设计

滚珠丝杠副传动只存在动摩擦,不存在爬行问题,因而灵敏度、传动精度和传动效率均较高。又由于无论是静止、高、低速运转,其摩擦扭矩几乎不变,故传动也平稳,它可广泛应用于各种数控机床和加工中心上。然而,要得到高精度的滚珠丝杠副,除对丝杠、螺母提出很高的制造要求外,反向器轨道设计也直接影响丝杠副的工作性能。因此,反向器轨迹的设计是滚珠丝杠副设计的关键因素。本文通过对内循环反向器的轨迹设计,以达到优化滚珠丝杠副设计的目的。     

考虑反向器影响的滚珠丝杠副摩擦力矩计算模型

基于赫兹接触和弹性碰撞理论,分别对滚珠丝杠副反向器入口和出口处滚珠的微观动态行为和受力平衡状态进行分析,揭示滚珠进出反向器时的碰撞和预紧受压对摩擦力矩的影响机理,建立同时考虑反向器入口及出口处影响的滚珠丝杠副摩擦力矩计算模型,并对某型丝杠进行了不同工况下的试验测试。对比分析表明,滚珠进出反向器产生的摩擦力矩是丝杠副摩擦力矩的重要组成部分,计入反向器的影响可以大幅提高摩擦力矩计算精度;其中反向器入口处因滚珠的连环碰撞使得其对摩擦力矩影响较大,而出口处的影响则相对较小。利用模型计算所得摩擦力矩,在不同转速及轴向载荷下均与实测值吻合良好,表明模型具有较高的计算精度。     

基于Pro/E的带复杂空间反向曲线的滚珠丝杠副的建模与装配

详细地介绍了带复杂空间反向曲线的内循环滚珠丝杠副三维建模方法与装配,其中介绍了典型滚珠丝杠、内循环滚珠螺母、带复杂空间反向曲线的反向器及循环滚珠链的建模及装配。此研究可以直观反映出零件设计的合理性,且为模具开发提供良好的设计基础。     

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.     

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。     

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....     

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.