曲柄摇杆机构的一种优化设计

提出以最小传动角γｍｉｎ 为最优目标,按给定行程速比系数优化设计曲柄摇杆机构。通过实例计算验证了一个命题［１］ 的正确性。     

NOVEL METHOD OF REALIZING THE OPTIMAL TRANMISSION OF THE CRANK—AND—RPCKER MECHANISM DESIGN

A novel method of realizing the optimal transmission of the crank-and-rocker mechanism is presented,The optimal combination design is made by finding the related optimal transmission parameters ,The diagram of the optimal transmission is drawn ,In the diagram,the relation among minimum transmission angle,the coeffcient oftravel speed variation,the oscillating angle of the rocker and the length of the bars is shown,concisely,conveniently and directly,The method possesses the main characteristic,That is is to achieve the optimal transmission parameters under the transmission angle by directly choosing in the diagram,according to the given requirements ,The characteristics of the mechanical transmission can be improved to gain the optimal transmission effect by the method,Especially,the method is simple and convenient in practical use.     

NOVEL METHOD OF REALIZING THE OPTIMAL TRANSMISSION OF THE CRANK-AND-ROCKERMECHANISM DESIGN

A novel method of realizing the optimal transmission of the crank-and-rocker mechanism is presented. The optimal combination design is made by finding the related optimal transmission parameters. The diagram of the optimal transmission is drawn. In the diagram, the relation among minimum transmission angle, the coefficient of travel speed variation, the oscillating angle of the rocker and the length of the bars is shown, concisely, conveniently and directly. The method possesses the main characteristic. That it is to achieve the optimal transmission parameters under the transmission angle by directly choosing in the diagram, according to the given requirements. The characteristics of the mechanical transmission can be improved to gain the optimal transmission effect by the method. Especially, the method is simple and convenient in practical use.     

PEF500×750复摆式破碎机的优化设计

复摆颚式破碎机广泛应用于现代工业,尤其是矿业.复摆式破碎机的运动机构为曲柄摇杆机构,其连杆即为动颚.优化的目的就是使其动颚出料口有更大的水平运动自由以更好地破碎物料,而限制其竖直运动以节约能源.优化的具体步骤是首先推导排料口的坐标公式,然后建立数学模型,接着用外点罚函数法对目标函数进行优化,最后用UG（UniGraphics）进行仿真模拟,测出排料口的位移、速度、加速度,观察优化结果.     

Structural Synthesis of Parallel Mechanisms with High Rotational Capability

Most parallel mechanisms(PMs) encountered today have a common disadvantage, i.e., their low rotational capability.In order to develop PMs with high rotational capability, a family of novel manipulators with one or two dimensional rotations is proposed. The planar one-rotational one-translational(1 R1 T) and one-rotational two-translational(1 R2 T)PMs evolved from the crank-and-rocker mechanism(CRM) are presented by means of Lie group theory. A spatial 2 R1 T PM and a 2 R parallel moving platform with bifurcated large-angle rotations are proposed by orthogonal combination of the RRRR limbs. According to the product principle of the displacement group theory, a hybrid 2 R3 T mechanism in possession of bifurcated motion is obtained by connecting the 2 R parallel moving platform with a parallel part, which is constructed by four 3 T1 R kinematic chains. The presented manipulators possess high rotational capability. The proposed research enriches the family of spatial mechanisms and the construction method provides an instruction to design more complex mechanisms.     

液压自动车床V带传动可靠性优化设计

V带传动常规的设计方法是以保证带传动不打滑又具有足够的疲劳寿命为准则进行的选择性设计,但由于带传动设计中的相关参数均为随机变量,且近似服从正态分布规律,从而使得设计结果很难达到最优。将带传动设计的有关参数按随机变量处理,以带传动具有足够的疲劳寿命和不打滑的可靠度以及小带轮直径、小带轮包角、中心距等为条件约束,根据有关可靠性设计理论和优化设计理论建立带传动优化设计的数学模型,应用MATLAB优化工具箱对液压自动车床带传动系统进行优化设计,得到了最优的传动方案。     

具有急回特性曲柄摇杆机构设计之“辅助线法”的进一步研究

对“辅助线法”作了引伸和补充 ,系统解决了已知行程速比系数 K>1、摇杆摆角 Ψ、机架长度 l4和曲柄长度l1 (或连杆长度 l2 )情况下 , 型、 型平面曲柄摇杆机构的图解设计问题。     

Vibration of skew plates by the MLS-Ritz method

This paper presents a study on the vibration of skew plates by a numerical method, the moving least square Ritz (MLS-Ritz) method which was proposed by the authors in a previous study [Zhou L, Zheng WX. A novel numerical method for the vibration analysis of plates. Computational mechanics WCCM VI in conjunction with APCOM’04, Beijing, China, 5-10 September 2004; Zhou L, Zheng WX. MLS-Ritz method for vibration analysis of plates. Journal of Sound and Vibration 2006;290(3-5):968-90]. One of the most challenging numerical difficulties in analysing the vibration of a skew plate with a large skew angle is the slow convergence due to the stress singularities at the obtuse corners of the plate. The MLS-Ritz method is employed in this paper to address such problem. This method utilises the moving least square technique to establish the trial function for the transverse displacement of a skew plate and the Ritz method is applied to derive the governing eigenvalue equation for the skew plate. The boundary conditions of the plate are enforced through a point substitution technique that forces the MLS-Ritz trial function satisfying the essential boundary conditions along the plate edges. Due to the flexibility of the arrangement of the MLS-Ritz grid points, more grid points can be placed around the obtuse corners of a skew plate so as to address the stress singularity problem at the corners. A series of cases for rhombic plates of various edge support conditions are presented to demonstrate the efficiency and accuracy of the MLS-Ritz method.     

单张纸胶印机歪斜套准机构设计

针对国内单张纸胶印机无歪斜套准机构,从而影响单张纸胶印机的工作效率,而国外进口拥有歪斜套准功能的高档单张纸胶印机原理复杂,对零部件的加工和装配精度要求很高,使国内印刷设备生产厂家对该功能望尘莫及。本文设计的无歪斜套准机构,简单易行,既解决了生产工作效率,又使其能在国产单张纸胶印机上得以实现。     

内平动齿轮减速器的模糊可靠性优化设计

内平动齿轮传动是一种新型的少齿差行星传动机构。综合运用了模糊数学理论和可靠性优化设计方法,建立了以体积最小为目标的内平动齿轮减速器的模糊可靠性优化数学模型,并给出了设计实例。     

新型内平动齿轮减速器的设计

在内平动齿轮传动原理的基础上利用平行四边形放缩机构作为外齿轮平动的发生机构,设计了一种新的内平动齿轮减速器。采用周向均布的4套放缩机构驱动两片啮合点相位差为180°的外齿轮,有效地平衡了传动过程中的惯性力。分析了平行四边形放缩机构的最佳传动角。通过分析渐开线少齿差啮合齿轮的干涉,得到了啮合参数的选择依据和计算步骤。最后设计了该减速器的三维实体模型,进行了运动仿真。该减速器具有传动比大、体积小、输入输出同轴线等优点。     

按最小传动角设计双曲柄机构

以双曲柄机构的尺寸参数为设计变量，提出了一种工作和非工作行程分别按不同的许用传动角设计双曲柄机构的新解析法，给出了机构设计的可行域，并将这种方法推广到按照最小传动角设计最佳传动双曲柄机构，还给出了设计实例。     

用MATLAB实现平台搬运车升降机构的优化

针对机械的最小传动角不能反映机构的总体传力性能的缺点,提出只要找出机构工作行程中的最佳传力效率系数,并尽量使设计的机构紧凑,才具有重要的实用意义。通过建立该类问题的目标函数和约束条件,并以MATLAB语言为工作平台,充分利用其强大的计算图形功能及可视化编程技术,编制程序对平台搬运车升降机构进行最优化设计。     

汽车双万向传动中间轴的模糊优化设计

双万向传动中间轴在传动过程中,伴有速度波动,为减少速度波动引起的动载荷影响,设计时要在传递转矩一定的情况下,使中间轴质量最轻。讨论了中间轴设计过程中的模糊因素,建立了以截面积最小的模糊优化设计模型,运用模糊理论和方法获得最优解。     

基于MATLAB的破碎机动力学参数优化设计

破碎机动力学参数设计包含机构平衡重、拉杆弹簧计算载荷、飞轮转动惯量等动力学参数的优化设计,是破碎机设计极其重要的内容.破碎机在运转过程中,其偏心轴、动颚、肘板等运动件都具有一定的加速度,会产生很大的惯性力而且大小、方向呈周期性变化.这些惯性力在运动副中引起附加动载荷,是破碎机零件磨损、机器振动的主要原因.破碎机动力学参数优化设计就是通过优化计算,获得最优的平衡条件,使机构总的惯性力平衡,其根本目的就是减小运动件的惯性力引起的附加动载,消除其有害影响,以确保破碎机运转稳定、可靠,降低机器的振动和噪声,提高设备的寿命和效率.以国内广为生产、使用的PE600×900破碎机为研究对象,利用MATLAB的优化功能,在进行运动学、动力学分析,建立一系列运动方程和力学模型之基础上,采用最优动力平衡法,在MATLAB环境下对破碎机机构平衡重进行优化设计.通过优化计算获得机构平衡重及其方向角的最佳值,使随机构位置而变化的振动力降低到最小.     

机场消防车传动系参数优化匹配

主要研究将优化理论引入到汽车传动系参数设计中,以汽车的燃料经济性为目标函数,以动力性能为约束条件,提出了汽车传动系参数的优化设计方法,以实现汽车发动机与传动系的最佳匹配,达到充分发挥汽车整体性能的目的.     

基于全膜弹流理论的交错轴斜齿轮传动多目标优化

针对交错轴斜齿轮传动传统设计中的不足之处，阐述了基于全膜弹流理论的交错轴斜齿轮传动优化设计的目的和意义。选择螺旋角β和齿数比u作为设计变量，油膜厚度和磨损量作为目标函数，啮合效率作为约束条件，合理运用多目标函数优化方法，得出不同工况下以及不同设计要求下的优化结果。     

基于有限元分析的变速器齿轮优化设计

文中用有限元分析方法,在静态分析的基础上,以各齿轮的体积为目标函数,以齿轮结构尺寸和设计许用应力为约束条件,建立了各齿轮的优化数学模型,采用ANSYS的APDL参数化设计语言将有限元分析与优化设计有机接合起来,编制用于复杂结构的优化设计程序,实现了自动的优化设计过程。     

曲柄摇杆机构的综合优化设计

在给定摇杆最大摆角的情况下,分析了行程速比系数和最小传动角与杆长的关系。采用多目标函数优化设计方法,分别建立了行程速比系数的隶属目标函数、最小传动角的隶属目标函数,总体尺寸的隶属目标函数,最后按行程速比系数最大、最小传动角最大、总体尺寸最小建立总目标函数对曲柄摇杆机构进行优化设计。     

按速度变化系数设计双曲柄机构

定义了双曲柄机构的速度变化系数，提出了按照速度变化系数和最小传动角设计双曲柄机构的设计方法，得到了最佳传动双曲柄机构的设计公式，给出了机构设计的可行域。