齿轮四杆机构连杆轨迹的尺度综合研究

建立了带有预定时标齿轮四杆机构连杆轨迹的数学模型，导出了计算机构实际尺寸和安装位置尺寸的数学公式，提出了通过对连架杆摆角算子进行快速Fourier变换（简称FFT），建立其数值图谱库，经过模糊识别进行连杆轨迹尺度综合的方法；最后给出了齿轮四杆机构连杆轨迹尺度综合的算例。     

带有预定时标齿轮摇杆滑块机构的连杆轨迹生成

利用Fourier级数理论和复矢量理论建立了带有预定时标齿轮摇杆滑块机构连杆轨迹的数学模型;分析了机构连架杆摆角算子与连杆轨迹之间的内在联系;导出了计算机构实际尺寸和安装位置尺寸等参数的数学公式;建立了包含对心和偏置两种情况在内的17205组机构基本尺寸型连架杆摆角算子的数值图谱库;实现了利用数值图谱法进行齿轮摇杆机构连杆轨迹的尺度综合;文中最后给出了综合算例。     

带有预定时标齿轮四杆刚体导引机构的生成

对带有预定时标齿轮四杆刚体导引机构生成进行了数学描述。分析了齿轮四杆机构连架杆摆角算子与连杆转角的内在联系 ,建立了包含 4 16 0 1组机构基本尺寸型的连架杆摆角算子数值图谱 ,推导出确定机构实际尺寸、连杆上标线的位置及安装尺寸等参数的计算公式。在此基础上 ,利用模糊识别方法进行刚体导引机构的尺度综合。运用该方法可以得到多个不同的机构方案 ,给出的算例充分证明了本方法的有效性和可行性     

利用数值图谱法进行齿轮四杆刚体导引机构的尺度综合

讨论了带有预定时标齿轮四杆机构的刚体导引位置函数与连架杆摆角函数之间的关系，并对连架杆摆角函数曲线的平移进行了分析，建立了包含34545组机构基本尺寸型连架杆摆角函数谐波成分的数值图谱库，实现了利用数值图谱法进行齿轮四杆刚体导引机构的尺度综合方法，最后给出了综合算例。     

小曲柄齿轮五杆轨迹同源机构的尺度综合研究

讨论了小曲柄齿轮五杆机构的尺寸约束条件,根据复矢量理论和Fourier级数理论,分析了小曲柄齿轮五杆机构连杆轨迹谐波特征参数的特性,为数值图谱库中数据的压缩奠定了理论基础,建立了较为完善的小曲柄齿轮五杆机构连杆转角算子谐波特征参数的数值图谱,并对双曲柄齿轮五杆轨迹同源机构的几何关系进行了分析,实现了利用数值图谱法进行小曲柄齿轮五杆轨迹同源机构的尺度综合.综合算例表明该方法实用方便.     

带有预定时标平面四杆机构连杆轨迹的尺度综合

应用复矢量方法和Ｆｏｕｒｉｅｒ级数理论建立了在一般位置时平面四杆机构连杆轨迹生成的数学公式,对其轨迹的谐波成分进行了理论分析;讨论了连杆轨迹与连杆转角算子之间的内在联系;推导出了在基本尺寸型通过模糊识别方法确定后机构实际尺寸、连杆上点的位置和机构安装尺寸参数的理论计算公式;结合这一思想建立了带有预定时标连杆轨迹尺度综合的步骤和方法;文中最后给出了综合算例。     

利用数值图谱法进行多杆直线导向机构的轨迹综合

给出了类四杆五杆机构的几何约束条件,讨论了类四杆五杆机构连杆轨迹与连杆转角算子之间的关系,建立了包含137052组机构基本尺寸型的特征参数数值图谱库,实现了对带有预定时标多杆直线导向机构的轨迹综合,文中最后给出了算例对其进行验证。     

机构连杆点轨迹曲率研究及有关机构设计

总结和完善了现有文献中的四杆机构连杆点轨迹曲率理论。叙述了另一套由绝对相对瞬心确定连杆点轨迹曲率中心的方法。阐述了由四杆机构尺寸确定连杆刚体拐点圆直径和方位的待定参数法及辅助垂线法。说明了确定连杆点轨迹曲率中心的新计算通式和图解法。讨论了各文献均未涉及的两连架杆平行情况。绘出了一个实际机构的曲率平稳点曲线图。给出了两个实用的鹤式起重机构及两个实用的六杆停歇机构设计结果。     

一类齿轮五杆轨迹同源机构的研究

借助于Roberts-Chebyshev定理,将曲柄摇杆轨迹同源机构的两曲柄分别用一双杆组代替,并要求双杆组满足一定的几何尺寸条件和运动条件,使变形后的机构为齿轮五杆机构,且满足机构的一个连架杆以及与其相连的连杆能够整周转动。通过对两机构间的几何关系分析和连杆平面上一参考点运动轨迹谐波成分分析以及机构运动仿真演示,证明了这两个机构为轨迹同源机构,并揭示了这种同源机构基本结构尺寸型间的内在联系。     

齿轮-五杆机构连杆曲线形状的全参数特性研究

分析了齿轮—五杆机构能整周转动的条件及其机构的类型，编制了该组合机构可变全参数的机构运动及其连杆曲线动画仿真显示系统。基于这一系统，研究了齿轮—五杆机构的连杆曲线形状随机构结构尺寸参数和传动比参数变化的规律及其混沌现象，为齿轮—五杆机构的轨迹综合提供了可参考的依据。     

Path curvature of a geared seven-bar mechanism

This paper presents a graphical technique to locate the center of curvature of the path traced by a coupler point of a planar, single-degree-of-freedom, geared seven-bar mechanism. Since this is an indeterminate mechanism then the pole for the instantaneous motion of the coupler link; i.e., the point coincident with the instantaneous center of zero velocity for this link, cannot be obtained from the Aronhold–Kennedy theorem. The graphical technique that is presented in the first part of the paper to locate the pole is believed to be an important contribution to the kinematics literature. The paper then focuses on the graphical technique to locate the center of curvature of the path traced by an arbitrary coupler point. The technique begins with replacing the seven-bar mechanism by a constrained five-bar linkage whose links are kinematically equivalent to the second-order properties of motion. Then three kinematic inversions are investigated and a four-bar linkage is obtained from each inversion. The motion of the coupler link of the final four-bar linkage is equivalent up to and including the second-order properties of motion of the coupler of the geared seven-bar. Then the center of curvature of the path traced by an arbitrary coupler point can be obtained from existing techniques, such as the Euler–Savary equation. An analytical method, referred to as the method of kinematic coefficients, is presented as an independent check of the graphical technique.     

Conjugate positions for planar four-bar mechanisms and corresponding special forms of the coupler-curvesKonjugierte stellungen bei ebenen viergelenkgetrieben und die zugenhörigen sonderformen der koppelkurven

Four-bar mechanisms and their variations yield two positions for which the output angle β or the coupler angle γ is identical. These positions are called “conjugate positions” and their significance is discussed. The kinematic inversions of mechanisms in certain conjugate positions leads to new mechanisms with special coupler curves. Coupler points which trace a path with two cusps are easily determined. A similar treatment of the non-turnable double rocker yields coupler curves with three cusps. Requirements for symmetrical coupler curves with two or three cusps can be satisfied.     

Synthesis of spherical four-bar path generators

In synthesizing a spherical four-bar path generator to generate a coupler curve passing through four given path points, and at the same time to coordinate the coupler point movements with three crank rotations, the fixed centre of the driving crank cannot be assumed arbitrarily. The locus of this centre point is a spherical sextic. An example is given.     

实现变传动比成组轨迹的混合驱动机构的综合

改变混合驱动五杆机构的尺寸参数和运动参数，可以得到不同的连杆曲线；因此可以采用混合驱动五杆机构实现具有不同传动比要求的、成组的连杆曲线。本文建立了实现成组轨迹的混合驱动机构的综合模型，实现了具有不同传动比要求的成组连杆曲线综合。     

RELIABILITY-BASED ANALYSIS AND SYNTHESIS OF MECHANICAL ERROR FOR PATH GENERATING LINKAGES

ＲＥＬＩＡＢＩＬＩＴＹ－ＢＡＳＥＤＡＮＡＬＹＳＩＳＡＮＤＳＹＮＴＨＥＳＩＳＯＦＭＥＣＨＡＮＩＣＡＬＥＲＲＯＲＦＯＲＰＡＴＨＧＥＮＥＲＡＴＩＮＧＬＩＮＫＡＧＥＳＳｈｉＺｈｏｎｇｘｉｕ，ＬｉＦｅｎｇｑｉａｎｇＱｉｎｇｄａｏＵｎｉｖｅｒｓｉｔｙＡｂｓｔｒａ...     

Optimization of parameters for specified path generation using an atlas of coupler curves of geared five-bar linkages

An atlas containing 732 coupler curves traced by the symmetric geared five-bar linkage has been drawn by the authors. Gear ratios of +1, −1, +2, −2, have been used. The data are presented either six or twelve curves to a page, arranged in axonometric projection to illustrate the envelope of a family of curves of that particular linkage geometry as the gearset phase angle isvaried. Dots on the curve represent uniform intervals of input crank angular displacement in order to provide coupler point velocity information. Other curves for parameters lying between those illustrated can be visually interpolated. Optimization techniques can be applied to modify the geometrics of a linkage parameters selected from the atlas as an approximate solution to the path motion desired. The origincurves are drawn on 11 × 17 sheets in four colors with a Benson-Varian xy plotter. Optimization algorithms are then used in conjunction with the atlas of linkage coupler curves to refine an initial selection of a desired motion path to achieve a particular motion with minimum deviation. The geared five-bar linkage is used as an example and a straight line generator is designed with less than 1% position error.