盘刀数控加工等基圆曲线齿锥齿轮的仿真

为实现使用盘形铣刀加工等基圆锥齿轮,根据等基圆曲线齿锥齿轮的现有研究成果及传统理论,通过求解刀具的廓形坐标,生成了VERICUT仿真加工中的盘形铣刀模型。根据盘形铣刀五轴联动数控加工运动轨迹,求解了机床运动坐标。利用VERICUT软件,针对某一设计参数的等基圆锥齿轮,进行了仿真加工。结果表明,刀具模型的建立、数控加工路径的规划、运动坐标求解均正确,盘形铣刀加工等基圆齿轮可以实现。     

盘刀加工等基圆锥齿轮的刀具位姿及运动轨迹计算

为了实现使用盘形铣刀数控加工等基圆曲线齿锥齿轮,基于等基圆曲线齿锥齿轮理论,通过建立盘形铣刀加工数学模型,求解了决定刀具空间姿态的主要参数。通过盘形铣刀刀轴矢量、刀心坐标的求解,得到了轮坯坐标系下的刀位。结合通用五坐标数控机床,求得了五坐标数控加工等基圆锥齿轮运动轨迹的表达式。通过三维造型,对刀位求解进行了分析验证;通过仿真切削加工,验证了运动轨迹的正确性。结果表明,利用盘形铣刀数控加工等基圆锥齿轮的刀具位姿、运动轨迹的求解正确,在通用数控机床上利用盘形铣刀能够加工等基圆曲线齿锥齿轮。     

钻井泵人字齿轮采用指形铣刀加工

以ZY3NB-1300型钻井泵的人字齿轮为研究对象,在借鉴国内外先进制造技术的基础上,从齿轮加工机床、加工图样、刀具种类及应用范围、提高表面质量途径以及工装设计等方面进行了总体分析,确定了人字齿轮的加工难点及在Y31200B滚齿机上用指形齿轮铣刀铣齿的加工方案.并针对本企业的实际情况,将指形齿轮铣刀的几何形状及结构、刀具材料的选择、切削用量的选择、切削液的选择等方面作为主要研究方向,提出了人字齿轮采用指形铣刀的加工方法.     

YX9332端面铣刀型高效齿轮倒角机的分析与应用

齿轮倒角机是用于变速箱滑移齿轮齿端倒圆角、倒尖角以及倒尖拱形角的齿轮加工机床,是汽车、拖拉机、机床齿轮的批量生产必不可缺的设备。 齿轮倒角机的类型有指状铣刀型和端面铣刀型。端面铣刀型属于新一代产品,它采用端面铣刀或碗形铣刀对内外齿轮端面倒角,其目的主要用于变速箱滑移齿轮,便于引导两齿轮进入相互啮合。齿轮倒角和倒棱的主要形式见图1。 图1 齿轮端面倒角形式 YX9332型为南京第二机床厂新近开发研制的新一代端面铣刀型高效齿轮倒角机,机床工件主轴按间断分度法分度,刀具主轴以插入式进给方式进行加工,工件主轴由分齿盘和定位齿精确定位,刀具主轴在水平面内相对工件主轴调整相交夹角,并沿被加工齿端面作轴向冲程运动,工件主轴每分度一个齿,刀具主轴往复冲程一次,完成切削过程。     

指形齿轮铣刀的设计、制造与使用

指形齿轮铣刀的设计、制造与使用洛阳矿山机器厂工具分厂（４７１０３９）许唯冲指形齿轮铣刀用于加工９级（或低于９级）精度的大模数直齿圆柱齿轮、斜齿轮、人字齿圆柱齿轮等。对于多列人字齿轮，指形齿轮铣刀是唯一的加工刀具。指形齿轮铣刀是按仿形原理进行切削加工的...     

等基圆曲线齿锥齿轮精确三维建模

为了进一步的来分析等基圆曲线齿锥齿轮的啮合和传动特点,以等基圆曲线齿锥齿轮的特征原理为基础,研究了齿轮的齿线特性以及刀具设计的方法。通过对指状铣刀进行运动分析,建立齿轮轮坯的切齿坐标系,完成齿轮齿面方程的求解。利用MATLAB对求解出的齿面方程进行编程处理,得到等基圆曲线齿锥齿轮单个齿凹凸齿面点云数据;将齿面点云数据按照特定的规律导出DAT文件;以DAT文件为建模基础,利用三维造型软件UG生成等基圆曲线齿锥齿轮精确三维模型。通过3D打印技术打印出来UG生成的齿轮三维模型,为在通用数控机床上利用指状铣刀铣削等基圆曲线齿锥齿轮提供了理论基础。     

用小直径指形铣刀加工特大模数少齿数齿轮

指形铣刀属于仿形刀具,使用指形铣刀在铣齿机、铣床上加工大模数、包括特大模数的齿轮不失为一种经济、实用、有效的办法。通常来说,一定模数的齿轮,齿数越少,齿轮齿形曲线的曲率越大。例如,加工-模数为50mm、齿数为17、分度圆压力角为20°的渐开线直齿圆柱齿轮,齿槽两侧面顶端宽度为141.33mm。指形铣刀的设计通常要留有一定的裕量,其最大直径至少要达145mm。制造这样大的指形铣刀是不容易的,这样大的刀具材料也不容易购置。本文提出用小直径指形铣刀加工特大模数少齿数齿轮的两种方     

大型风电传动齿轮成形铣削刀具刃形曲线设计

基于成形原理加工齿轮廓形的盘铣刀是生产大型风电传动齿轮的必备刀具。然而,受加工原理误差影响,传统齿轮盘铣刀只能针对特定模数和齿数齿轮进行加工,刀具通用性差。传统刀具廓形不能够保证被加工齿轮的加工精度与使用寿命,无法最大程度发挥成形铣削的原理优势。基于此建立了齿轮渐开线实际廓形曲线数学模型,分析了共轭齿条顶角相对运动轨迹,建立了齿根过渡曲线方程,依据齿根过渡圆弧空间相对位置,重构了不同形式齿廓曲线的设计方式;基于逆向投影法,以被加工齿轮的各项参数为变量,建立了刀片刃形曲线数学模型,根据刀片空间包络原理,重构了可转位齿轮盘铣刀廓形曲线设计方式;进行了齿轮齿廓及刀片刃形曲线数值分析,研究了大型风电传动齿轮齿廓曲线以及可转位齿轮盘铣刀刀片刃形曲线的主要形式,研究结果为大型齿轮廓形成型加工提供技术支持。     

大模数直齿轮数控精铣削方法的研究

针对大模数齿轮加工采用盘形、指状铣刀存在着加工效率低,专用刀具造价昂贵的问题,提出了用普通铣刀数控加工大模数齿轮的方法,涉及走刀方式、走刀步长的确定、切削关键点的处理。依据提出的方法建立了齿轮毛坯与刀具运动关系的数学模型,推导了渐开线上点以及刀位点在该模型中的轨迹方程以及刀具与工件之间运动关系方程。该数学模型在齿轮参数已知的情况下能够计算出刀位点以及刀心按照齿轮渐开线齿廓运动的一系列轨迹,利用MATLAB的数据可视化功能,通过刀位点的轨迹方程计算出刀位点,依据齿轮参数绘制出齿轮基圆以及渐开线齿廓,选择合适的刀具半径绘制刀具轮廓,令刀具轮廓跟随刀位点产生一系列刀具轮廓,从而形象直观的对该数学模型进行验证,在理论上分析了该方法的可行性。     

椭圆弧齿圆柱齿轮的一种铣削加工方法

在研究圆弧齿线圆柱齿轮的基础上,提出了全齿宽啮合型椭圆弧齿圆柱齿轮的铣削加工方法。通过分析其理想几何参数,推导了齿轮齿面及啮合重合度方程。利用齿轮齿条模型分析了刀具与椭圆齿线的形成过程,提出椭圆弧齿圆柱齿轮的铣削加工原理,并进行了齿轮的铣削加工。斜安装的刀具加工形成的齿轮在径向截面上都是渐开线齿廓,齿线在分度圆柱面的展开曲线为椭圆的一部分,凸齿面齿线与凹齿面齿线具有相同的几何形状参数。该加工原理可以完成椭圆弧齿圆柱齿轮的高效铣削,也适用于该齿轮的磨削。     

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...     

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。     

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。     

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.     

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.     

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.     

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.