二齿差摆线针轮行星传动原理与几何计算

前言一般的摆线针轮行星传动是采用完整的短幅外摆线作摆线轮的理论齿廓,其齿数差只能是一,这样的摆线针轮行星减速器在传动比较小时,齿面易产生胶合;目前国内外少数单位采用二齿差摆线针轮行星传动,根本上解决了传动比较小时的齿面胶合问题。但目前公开发表的资料尚不多,并不够全面;因此很多同行来信要     

RV减速器动载特性建模与分析

RV减速器是工业机器人的核心部件,而动载特性又是其结构设计的核心问题。文中针对RV减速器结构复杂、动力学分析理论建模难度大等特点,基于虚拟样机技术,采用Pro/E参数化建模和ADAMS软件,建立了RV减速器的动力学模型。以针齿与摆线轮的啮合力为目标,研究分析了各项设计参数对啮合力的影响及其规律,结果表明,啮合力随摆线轮齿数、短幅系数、针齿中心分布圆半径的增大而减小,啮合力和针齿半径之间呈非线性关系,摆线轮齿数、短幅系数、针齿中心分布圆半径是影响啮合力的主要因素,针齿半径的影响幅度相对较小;并探讨了各参数对RV传动的影响,研究结果对RV减速器的设计具有重要的指导意义。     

二齿差摆线针轮行星传动中摆线轮齿廓顶部修形参数的优化计算

本文对二齿差摆线针轮行星传动中采用短幅外摆线的等距曲线对摆线轮齿廓顶部进行修形的问题作了探讨。建立了计算修顶摆线合理参数的数学模型、并编制了优化计算程序。还给出了JB2982—81标准所规定的摆线针轮减速器系列中,传动比为17及以下的几种机型采用二齿差传动时,其摆线齿轮修顶曲线的合理参数,可供实用。     

二齿差摆线针轮行星传动中摆线轮等效代换齿廓的研究

二齿差摆线针轮行星传动具有较强的齿面抗胶合能力，但由于二齿差摆线轮齿廓曲线的不连续性，给传动带来了不良的影响，并造成工艺上的复杂性，对此，本文提出了采用完整的短幅外摆线的等距曲线作为摆线轮齿廓，来等效地代换二齿差摆线针轮行星传动中的摆线轮齿廓的理论，并给出了求解等效代换齿廓参数的数学模型，计算方法和求解实例，采用等效代换齿廓既可消除尖点，又能保证传动性能相同。     

二齿差摆线针轮行星减速器的优化设计

本文分析了二齿差摆线针轮行星传动的啮合原理和强度计算方法。考虑了针齿分布、针齿与柱销强度、转臂轴承寿命等１２种约束条件，提出以针齿分布圆直径、针齿直径、摆线轮宽度、摆线轮内孔直径、短幅系数、销轴孔分布圆直径和销轴直径为设计变量，以体积最小、成本最低为目标函数的优化设计方法，研制出了该型减速器运动分析、强度计算、参数设计的一体化设计软件包。     

摆线针轮行星减速器多目标优化设计

分析了摆线针轮行星传动的特点,提出以针齿分布圆直径、针齿直径、摆线轮宽度、摆线轮内孔直径、短幅系数、销轴孔分圆直径和销轴直径为设计变量,以体积最小、效率最高为目标函数的优化设计方法,研制出了该型减速器运动分析、强度计算、参数设计的一体化设计软件包。     

RV减速器的虚拟样机仿真与传动精度的研究

通过摆线轮齿廓方程在UG环境下建立摆线轮的参数化模型,进而建立RV减速器的三维模型,将模型导入ADAMS软件中,得到RV减速器虚拟样机模型。通过仿真得到输出轴、曲柄轴和摆线轮的转速,考察了摆线轮与针齿的啮合频率,仿真结果为9.73 Hz,与理论结果一致,验证了所建虚拟样机模型的合理性与正确性。建立了考虑误差的8组虚拟样机模型,仿真结果表明,摆线轮修形、针齿销半径误差、针齿中心圆半径误差均对传动精度有较大影响。研究结论为RV减速器的设计提供了一定的理论依据。     

圆弧齿行星减速器的效率计算

圆弧齿行星传动为一种K-H-V型行星传动,如图1所示。这种传动的行星轮a为一纯圆弧齿的外齿轮,与其相啮合的内齿轮b为一装有圆柱形针齿的针轮。由于内、外齿轮齿数相差较少(常为一齿差),故为一种新型少齿差传动。圆弧齿行星减速器的结构与目前广泛使用的摆线针轮行星减速器基本相同,其工作原理是依据长幅外摆线的形成原理而动作的。     

RV减速器两级传动特性耦合分析

针对RV减速器的传动结构特点,应用Pro/E参数化建模技术,建立了RV减速器的三维实体模型,并以RV-40E为例,采用ADAMS软件对一级传动和二级传动进行运动学与动力学耦合仿真,分析了一级传动和二级传动的动力学特性对RV减速器传动特性的影响,并对其进行整机动力学分析。结果表明:一二两级传动对曲柄轴转速波动均有影响;二级传动导致输出轴转速波动的幅度远大于一级传动;针齿与摆线轮之间的啮合力因曲柄轴自转(摆线轮公转)而呈周期性波动,啮合力幅值随摆线轮修形量的增加而增大;曲拐轴承转动副受力巨大,易导致轴承损坏。研究结果对RV减速器的产品化设计具有重要的参考价值。     

变齿厚RV减速器传动效率的理论分析

变齿厚RV减速器克服了摆线针轮RV减速器中摆线轮加工困难、生产成本高,且对啮合中心距要求过于敏感的问题,但在回差和传动效率两方面还有待改善。因此,提出在结构上对现有的变齿厚RV减速器进行改进,将其高速级的渐开线外啮合副替换成变齿厚外啮合副,以使减速器的回差能够调至最佳状态。其次,将作为啮合效率影响因素的啮合角、锥角、变位系数等参数为设计变量,以提高传动效率为目标,对变齿厚RV减速器进行优化分析。最后,将优化后的变齿厚RV减速器与现有的变齿厚RV减速器的传动性能进行了比较,证明了前者的优越性。     

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.     

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.