Kinematic Modeling and Characteristic Analysis of Eccentric Conjugate Non- circular Gear ＆ Crank-Rocker ＆ Gears Train Weft Insertion Mechanism

A novel weft insertion mechanism named eccentric conjugate non-circular gear & crank-rocker & gears train weft insertion mechanism was proposed in order to better meet the requirements of rapier loom’s weft insertion mechanism as well as reduce the manufacturing difficulty. Meanwhile, based on the working principle of this mechanism, kinematical mathematic models of this mechanism were established and an aided analysis and simulation software was compiled. The influences of eccentricity ratio, deformation coefficient, and other important parameters on the kinematics characteristics of this mechanism were analyzed by using the software. A group of preferable parameters which could meet the requirements of weft insertion technology were obtained by means of human-computer interactive optimization method. The maximum velocity, maximum acceleration, and variation of acceleration of this mechanism are smaller than those of the conjugate cam weft insertion mechanism applied on TT96 rapier loom under the conditions of the same unilateral total stroke of rapier head and the same rotary speed of loom spindle; meanwhile the other demands of weaving technology can be met by this novel weft insertion mechanism.     

Top Gear热讽中国山寨车

看看你开的国产汽车被他们骂成什么样。     

Torsional Vibration of Roller Oscillating Tooth Gear Drive

ＩｎｔｒｏｄｕｃｔｉｏｎＲｏｌｌｅｒｏｓｃｉｌｌａｔｉｎｇｔｏｏｔｈｇｅａｒｄｒｉｖｅ (ＲＯＴＧＤ)ｉｓａｎｅｗｔｙｐｅｏｆｓｍａｌｌｔｅｅｔｈｄｉｆｆｅｒｅｎｃｅｐｌａｎｅｔａｒｙｇｅａｒｄｒｉｖｅ .Ｉｔｓｆｅａｔｕｒｅｓｉｎｃｌｕｄｅｓｍａｌｌｖｏｌｕｍｅ ,ｃｏｍｐａｃｔｓｔｒｕｃｔｕｒｅ ,ｈｉｇｈｌｏａｄｃａｐａｃｉｔｙ ,ｈｉｇｈｔｒａｎｓ ｍｉｓｓｉｏｎｅｆｆｉｃｉｅｎｃｙ .Ｔｈｅｒｅｆｏｒｅ ,ｉｔｉｓｅｘｐｅｃｔｅｄｔｏｂｅｗｉｄｅｌｙａｐｐｌｉｅｄｉｎｅｎｇｉｎｅｅｒｉｎｇｆｉｅｌｄｓ…     

基于Gear算法的一个符号化仿真系统设计原理

控制系统仿真是研究控制系统不可缺少的技术手段，其核心问题是求微分方程组与代数方程组的联立数值解，即求数值积分。微分方程组的数值解法很多，其中Gear算法最适合控制系统仿真，它稳定性好，是一种变阶变步长的预报校正型的多步方法。基于Gear算法设计了面向框图、微分方程、状态方程对象的仿真程序，其输入设计为符号化的参数输入方式，并给出了应用实例。     

基于Gear算法的一个符号化仿真系统设计原理

控制系统仿真是研究控制系统不可缺少的技术手段，其核心问题是求微分方程组与代数方程组的联立数值解，即求数值积分。微分方程组的数值解法很多，其中Gear算法最适合控制系统仿真，它稳定性好，是一种变阶变步长的预报校正型的多步方法。基于Gear算法设计了面向框图、微分方程、状态方程对象的仿真程序，其输入设计为符号化的参数输入方式，并给出了应用实例。     

Analysis of the Cut-thickness in the Process of Gear Shaping

1introduction Intheprocessofmanufacturingcolumngear,thegearshaping isextensivelyadopted,butsometimesitiscompaniedwiththe gear’sextrusionwoundandthecutter’sabnormalabrasion wear.Onegenerallythinksthatthisphenomenonisrelatedto thecut thickness’variationduringthegearshaping.Soasetofformulastohelpstudythevariationofcut thicknessofchipscuttedoffwiththecutedgeandtotryto findoutthecauseoftheextrusionwoundofthegearandthe abnormalabrasionwearintheprocessofgearshapingwere deduced.2TheCut thicknessoft…     

一类含有稳定参数的Gear型隐式方式

本文导出解ｓｔｉｆｆ方程的一类含有稳定参数Ｓ的Ｋ步Ｋ阶的ｓｔｉｆｆ稳定的Ｇｅａｒ型隐式方法，我们可以通过适当选取参数Ｓ，改进其绝对稳定性。保证零稳定和无穷远稳定．它比相应的Ｇｅａｒ方法［１］。变更的Ｇｅａｒ方法［３］和Ｅｎｒｉｇｈｔ方法［２］有更大的绝对稳定域，并且构造方便，计算简单。     

Q＆A

我们的耳朵由外耳、中耳和内耳三个部分组成，中耳是传导声波的主要部分。鼓室是中耳的核心组成部分，它是一个不规则的空腔结构，体积不超过2毫升，有上、下、前、后、内侧、外侧共六个壁，各壁都有其不同性质的重要结构，功能也各不相同。在鼓室的前壁上，有一个小孔通向一条直接与外界相通的管道，     

葡萄酒＆食物

总统出访被批浪费 6月初,奥巴马前往芝加哥参加两场筹款会,乘坐空军一号的成本为每小时18万美元。同一天,第一夫人米歇尔与持单价3.76万美元入场券的富豪们在波士顿共进午餐,餐桌上有烤智利海鲈鱼及白汁芦笋肉。对于身处削减开支时代的领导人来说,     

Q＆A

在关于汶川地震的新闻报道中，我们往往能看到救援人员手持“生命探测器”在废墟上搜寻。这究竟是种什么仪器，它们如何起作用，又分别起什么作用？     

Design and Experiment of Non-circular Combined Gear Train Beating-up Mechanism

The most important performance of a beating-up mechanism is that the dwelling time of the sley must ensure the completion of the weft insertion. To meet this requirement, a new non-circular combined gear train beating-up mechanism which is composed of two-stage planetary gear trains is proposed. The first-stage is a Fourier planetary gear train and the second-stage is a non-circular planetary gear train. For designing of this new mechanism, the ideal kinematic equations of the sley are constructed first. Then the kinematic model of the first-stage Fourier planetary gear train is established and the reverse solution for the pitch curves of the second-stage non-circular gears is deduced. With a computer-aided design program, the influences of several important parameters on the pitch curves of the second-stage non-circular gears are analyzed, and a set of preferable structural parameters are obtained. Finally, a test bed of this mechanism is developed and the experimental results show that this new beating-up mechanism can achieve the designed dwelling time, namely it can meet the requirements of beating-up process.     

Kinematic Analysis of Elliptic-Gear ＆ Eccentric Slider-Crank ＆ Uniform-Pitch Screw Weft-Insertion Mechanism

In order to analyze the kinematic performances of elliptic-gear & eccentric slider-crank & uniform-pitch screw weft-insertion mcchanism proposed by us, kinematic mathematic models of the mechanism were established,and an aided analytic software was compiled. Influences of some important parameters on the kinematic characteristics of the mechanism were analyzed. A group of preferable parameters were obtained according to the software and some requirements. Comparisons of kinematic performances were made between the proposed mechanism and the variable- pitch screw insertion mechanism of C401 rapier loom manufactured by Vamatex Corp in Italy. The results show that the proposed mechanism can meet the requirements of inserting wefts.     

剑杆引纬连杆机构的创新分析与设计研究

通过对典型剑杆织机传剑机构的运动弹性动力学研究,概括地提出了较理想引纬传动方案所应具备的主要性能特点,由此可创新设计出一种具有复合运动的全转动副空间连杆引纬机构.     

剑杆织机打纬引纬系统结构尺寸误差对打纬和引纬运动的影响

本文用矩阵法分析了剑杆织机系统结构尺寸误差对打纬和剑头引纬运动的影响,建立了打纬和剑头运动两者的误差与系统各结构参数误差之间关系的矩阵方程。以1511普及型剑杆织机为实例进行了分析计算,得到了较满意的结果。本文所述及的方法具有一般性。     

渐开线锥形非圆齿轮的啮合原理与仿真模型

根据渐开线锥形齿轮传动理论结合非圆齿轮齿廓包络原理,以齿条作为齿廓形成的媒介,提出一种基于齿条加工渐开线锥形非圆齿轮的方法,并建立了相应的加工数学模型. 基于该模型,证明了齿条与非圆齿轮纯滚动的运动关系,推导出啮合方程和瞬时接触线方程,以及经过坐标变换后得到渐开线锥形非圆齿轮的参数方程,对比了各种形式的渐开线齿轮齿廓形成特点. 借助数值计算软件对上述方程进行了验证,通过三维造型工具给出了渐开线锥形非圆齿轮的直观图形,从而验证了该方法的正确性和有效性.      

Design of Electronic Weft-Insertion System for Three-Dimensional Loom

The motion laws for rapier weft insertion mechanism are analyzed. According to the special requirements on rapier loom's weft-insertion system for weaving three-dimensional( 3-D) fabric,a new rapier electronic weft-insertion system is presented. The design principle for 3-D loom's weft insertion system is introduced,including the design of the motion law of electronic weft-insertion system,the driving system's hardware configure,and its software's controlling principle. The weft insertion system is computer-controlled and servocylinder driven so as to control the rapier's movement to insert the weft into the multi-shed while 3-D weaving. This method greatly simplifies the weft-insertion system,achieves weft-insertion with variable travel,and improves the flexibility and reliability. The weft insertion system has been applied in a 3-D loom successfully.     

非圆齿轮无级调速特性分析与设计

针对非圆齿轮的时变速比特性，采用多段函数构造法实现了非圆齿轮副预设速比函数的再现设计；结合工程实际，提出了一种新型的非圆齿轮无级调速机构，推导了非圆齿轮无级调速机构的基本参数与输出速比的影响规律。根据机械原理、齿轮啮合理论与现代设计方法，采用SolidWorks和Adams等软件，建立了非圆齿轮无级调速机构的仿真模型，对非圆齿轮无级调速机构进行仿真，结果表明：改变非圆齿轮副间的相位差，该无级调速机构可以得到变化的输出速比，获得了该无级调速机构的输出速比与相位差的影响规律；搭建了非圆齿轮实验台，得到非圆齿轮副的实验速比与理论速比变化趋势一致，最大实验误差6.8%,验证了无级调速机构和非圆齿轮理论分析的可行性和正确性。     

非圆齿轮引纬系统

利用非圆齿轮与连杆机构串联组合可以得到所需运动规律的优点,这里提出了用非圆齿轮机构引纬的新思想,并完成了一个引纬系统实例的设计计算。     

GA74型剑杆织机改造中引纬机构的优化设计

GA74型剑杆织机由于其筘座脚长和钢筘摆幅大,故其速度不能有效地提高,这里给出了改造后的引纬机构,并用优化设计的方法,在满足织机的工艺条件和运动性能等约束条件的基础上,获得了设计方案的一组较理想的参数.     

An Analysis of the Orthogonal Crank-rocking Lever Spatial Mechanism for the Weft Insertion in Rapier Looms

On the basis of the analysis of typical orthogonal crank-rocking lever spatial mechanism for the weft insertion in rapier looms, the rules of the outputting lever motion and the mechanism pressure-angle variety are studied when the maximum swing angle of rocking lever and the length of outputting lever have different values, and the optimum parameters suitable for motion transmission can be chosen. At the same time some existing shortpoints of the mechanism are also pointed out.