弧齿锥齿轮大重合度设计及啮合性能对比

为了改善弧齿锥齿轮啮合性能,提出了一种接触路径沿齿长方向的大重合度设计新方法.预置弧齿锥齿轮副的设计重合度和传动误差幅值及对称性,通过迭代优化局部综合参数,获得内对角和沿齿长的大重合度齿面印痕.借助齿面接触分析和轮齿承载接触分析,进行了两种大重合度设计在轮齿强度和承载传动误差上的比较.算例表明,接触路径沿齿长方向的大重...     

弧齿锥齿轮的高重合度设计

针对航空和汽车弧齿锥齿轮对强度、动态性能和可靠性的特殊要求，提出了高重合度弧齿锥齿轮的设计方法。这种设计是通过增加工作齿高和调整齿面啮合路径方向以及优化加工参数实现的。结合弧齿锥齿轮的实际工况，提出了在不同载荷和安装误差下，实际重合度的综合分析方法，达到了既提高重合度又控制齿面啮合质量的目的。     

高重合度弧齿锥齿轮的三维建模及加工试验

重合度较大时,参与啮合齿的对数增多,齿轮传动就越平稳,每齿承载的力也减小,这对于降低噪声是非常有利的。根据螺旋锥齿轮的非零变位原理,进行负传动设计,改善其啮合性能。在此基础上,借助于局部综合法、TCA技术等仿真方法,通过改变接触路径的倾斜角度,以获得具有较大重合度的弧齿锥齿轮。对新型设计和常规设计两种方案的几何参数和加工参数进行了对比,并创建齿轮副的精确三维模型,基于UG运动仿真功能模拟大小轮接触区状况。铣齿试验表明,接触区良好,易于调整,验证了利用局部综合法与非零变位技术设计的高重合度弧齿锥齿轮的可实施性。     

双圆弧弧齿锥齿轮重合度研究

重合度是影响弧齿锥齿轮传动啮合性能的主要因素。双圆弧弧齿锥齿轮的端面重合度为零,其连续传动由纵向重合度保证。根据弧齿锥齿轮重合度的定义,提出了双圆弧齿廓弧齿锥齿轮重合度的定义,并采用线图法对其啮合过程进行了分析;建立了双圆弧齿廓弧齿锥齿轮重合度、多点啮合系数和多齿对接触系数等计算方法,给出了双圆弧弧齿锥齿轮连续传动的条件。应用提出的方法对试验齿轮的重合度进行了理论计算,计算结果与TCA分析结果相同,验证了所提出方法的正确性。     

曲面综合法少齿数弧齿锥齿轮加工参数计算仿真与切齿试验

少齿数高减比齿轮传动具有体积小和轻量化的优势。根据综合变位和节锥外啮合原理,设计了一对高减速比弧线等高齿锥齿轮,给出了相关的几何限制条件,推导了大、小轮齿面方程。大轮采用成形法加工,小轮采用单面展成法加工,为弥补大轮齿廓曲率的不足,小轮刀齿采用圆弧刃修形,采用曲面综合法优化求解了小轮加工参数;通过建立ease-off差齿面,对齿面修形梯度、传动误差、接触路径与接触线进行了仿真。切齿和滚检试验,验证了高减比弧齿锥齿轮几何设计、刀盘修形加工方法的可行性。     

小模数弧齿锥齿轮的三维建模与应用分析

针对小模数弧齿锥齿轮,提出了一种新的加工组合:小轮采用传统的双面法铣齿加工,设计大轮齿面加工参数,控制大轮的两齿面分别与小轮齿面相配。根据以上加工方法,设计小模数弧齿锥齿轮良好啮合的齿面加工参数,并创建齿轮副的精确三维模型。在UG软件环境下,可以完成齿轮副的虚拟装配、干涉检查。设计的小模数弧齿锥齿轮的齿面可以保证齿面的良好啮合,完成的三维模型可以应用于小模数弧齿锥齿轮的模具成型加工。     

基于MATLAB的弧齿锥齿轮啮合质量仿真分析

随着弧齿锥齿轮在航空、汽车等领域的广泛应用,如何提高轮齿啮合质量就成为制约弧齿锥齿轮使用性能和可靠性的突出问题.为解决这一问题,研究了根据齿轮加工参数对弧齿锥齿轮啮合情况进行仿真分析的方法,并以MATLAB软件为工具对弧齿锥齿轮进行轮齿接触分析,提出了适合MATLAB运算特点的数学模型及其求解步骤,从而为提高弧齿锥齿轮的设计质量和设计工作效率提供了有效手段.     

曲面综合法弧齿锥齿轮加工参数计算

针对现有弧齿锥齿轮加工参数计算方法,接触点综合纷繁复杂的问题,提出ease-off曲面综合法。从微分几何学出发,给出二阶密切曲面的定义及其构造方法;在二阶精度范围内,密切曲面与原有曲面具有相同的微分几何属性,从而可以替代原有的曲面分析。通过弧齿锥齿轮加工的产成模型,构造大小轮共轭齿面的ease-off差齿面,利用ease-off差齿面的密切曲面完整地拓扑齿面接触区;利用齿面接触区的可控参数综合确定小轮齿面的接触参数,进而通过数值优化方法求解小轮的加工参数。籍助ease-off密切曲面进行了啮合仿真,完整呈现了齿面接触区大小形状、接触路径方向、抛物线失切量等轮齿啮合信息。所提出的方法适宜于数值方法,基于齿面接触区的完整性,实现了齿面啮合性能较好控制。     

弧齿锥齿轮啮合过程动态应力分析

介绍了利用ANSYS对弧齿锥齿轮进行瞬态啮合的前置处理、划分网格、使加约束的方法。基于目前弧齿锥齿轮的应力分析研究现状。对齿面啮合质量进行了齿面接触分析(TCA),并且利用在CAE方面有很强能的ANSYS软件对弧齿锥齿轮进行啮合状态下的动态仿真[5-7],得到较为准确的齿面接触应力和齿根弯曲应力。建立了弧齿锥齿轮三维有限元非线性接触模型,对弧齿锥齿轮在一定的转速和负载转矩下进行了动态啮合仿真,得到了一个啮合周期下的齿轮齿面接触应力和齿根弯曲应力的变化规律。进行了轮齿加载接触分析(LTCA),得到了轮齿啮合传动中的齿面接触应力、弯曲应力变化过程。该方法可以进一步为弧齿锥齿轮强度分析和疲劳寿命计算提供理论依据。     

高强度弧齿锥齿轮的齿形建模及加工试验

非零正变位设计的弧齿锥齿轮具有较高的强度,对该齿轮副法进行大重合度加工参数设计,可弥补正传动设计由于啮合角增大而使得重合度降低的不足。对比了非零正变位设计与常规设计的几何参数与加工参数,并对设计参数进行了TCA分析;基于UG对大轮进行了齿根受力分析。进行了齿轮的铣齿加工与滚动检查实验,结果表明,利用局部综合法与非零变位技术可以设计高强度的弧齿锥齿轮,实际加工的齿轮副啮合状况良好。     

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...     

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...     

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。     

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。     

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.     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

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.     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.     

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。     

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...