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平面四杆机构的蜕变位置研究 总被引:1,自引:0,他引:1
本文对平面四杆机构的蜕变位置进行了研究,给出了平面四杆机构蜕变位置的定义和分类,论证了平面四杆机构处于蜕变位置的条件,分析了平面四杆机构处于蜕变位置的特性,论述了蜕变位置的消除方法和利用措施。 相似文献
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王美蓉 《机械制造与自动化》2014,(6)
分析了四种典型的平面四杆机构的急回特性,对这四种机构急回程度的可变性、运动变化方式和机构的动力传递等方面进行了比较分析,有助于更好地理解具有急回特性的平面四杆机构的特性;结合实例讨论了平面四杆机构的应用问题,可为工程实践中合理选用平面四杆机构提供理论依据。 相似文献
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池丽婷 《机械工程与自动化》2011,(4)
急回特性是平面四杆机构的重要特性,极位夹角的大小决定着急回特性的程度.针对现有极位夹角定义存在的缺陷,对平面四杆机构极位夹角的定义做了较确切的表述,并且对行程速比系数的可能取值范围进行了分析. 相似文献
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平面四杆五接头拍扬机构之新构造设计 总被引:1,自引:0,他引:1
对平面四杆五接头拍扬机构进行新构造设计研究。依据现有机构,分析归纳其拓朴构造特性,并订定设计需求限制,以颜氏创造性机构设计方法,进行一般化、特殊化、特性编码及具体化,设计出符合设计需求与限制条件的六个平面四杆五接头拍扬机构新构造。 相似文献
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平面四杆机构死点问题探讨及应用 总被引:2,自引:0,他引:2
主要以曲柄摇杆机构为例,分析了平面四杆机构死点实质、极限位置、形成死点条件等,为平面四杆机构解决死点问题、利用死点特性提供了理论依据。研究发现机构死点问题可以设法消除,而且存在着一定的应用和发展空间。 相似文献
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混合驱动平面六杆机构具有两个自由度,其动力学模型是一个高度非线性强耦合系统。通过分析平面六杆的动力学特性,建立了基于拉格朗日方程的混合驱动平面六杆机构系统动力学模型,并对动力学模型的特点进行分析。 相似文献
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针对傅里叶级数理论不能进行非整周期刚体导引综合的问题,提出了基于Haar小波级数的解决方法,将早期提出的解决平面四杆机构轨迹综合问题的方法扩展到平面四杆机构的刚体导引综合中。通过对刚体转角和其对应基本尺寸型的连杆转角小波系数进行分析,发现了二者的内在联系。在此基础上建立了101 408组基本尺寸型的平面四杆机构刚体导引输出特征参数数据库。将位置输出问题转化为平面四杆机构轨迹综合问题,并给出了计算平面四杆机构实际尺寸和机构安装位置参数的理论公式。利用建立的数据库和理论公式,实现了平面四杆机构非整周期刚体导引综合。以生产线上的输送工件的铰链四杆机构为例,证明了本文方法的有效性和可行性。 相似文献
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《Mechanism and Machine Theory》1987,22(3):225-230
Function-cognates are those mechanisms that provide exactly the same input-output displacement relationships as the original mechanism. Dissimilar cognates are cognates having a different structure from that of the original mechanism. It is shown that there are no RSSR mechanisms function-cognate to a given planar four-bar or spherical four-bar. On the other hand, formulae for the infinity of RCR0CR cognates of the planar four-bar are given. It is further shown that for a given RCR0CR mechanism (or for a given general trigonometric implicit relationship linear in cosines and sines of input and output rotations individually), there is always one and only one RSSR mechanism giving the same relationship. The latter is therefore also the case for an eight-precision point synthesis of the RSSR mechanism. 相似文献
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The force transmissivity index of planar linkage mechanisms 总被引:1,自引:0,他引:1
In this paper, a new force transmissivity index (FTI) of planar linkage mechanisms is proposed. The index is used to quantitatively measure the force transmission quality from the input link to an output link. Traditionally, the transmission angle is used to measure the ability to transmit motion for planar four-bar linkages. However, the transmission angle is usually limited to be used at four-bar linkages due to the structural simplicity. For complex multi-loop mechanisms, it is often difficult to define the force transmissivity. Here we have established a procedure of force transmissivity analysis for planar linkage mechanisms. The method is based on the static force analysis and the concept of power flow path. It is found that the force transmissivity of a mechanism depends not only on the configurations of the mechanism, but also on the selection of the output link and the forms of the loading. We have compared the results based on the FTI with the results from the Jacobian matrix method and the joint force index (JFI) method for four-bar mechanisms. It shows that the proposed FTI can describe the force transmission performance more accurately than other methods do. It is concluded that the index can be used as a better measure of force transmissivity analysis for planar linkage mechanisms. 相似文献
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机构优化设计综述与研究 总被引:1,自引:0,他引:1
简要介绍了优化设计的一些基本概念和常用方法。在优化设计理论知识的的基础上,对平面四杆机构和蜗杆传动机构做了具体的优化设计研究。应用现代优化设计理论技术建立机构优化设计的数学模型后,结合MATLAB软件,论证了MATLAB在机构优化设计中的应用。并且对优化后的优化平面四杆机构作了动态仿真。结果表明,优化后的机构具有确定的几何尺寸,能够满足运动学要求,并能实现给定的运动规律。 相似文献
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A mechanism is said to be force balanced if, for any arbitrary motion, it does not apply reaction forces on the base. Moreover, if it does not apply torques on the base, the mechanism is said to be moment balanced or dynamically balanced. In this paper, a new method to determine the complete set of force and moment balanced planar four-bar linkages is presented. Using complex variables to model the kinematics of the linkage, the force and moment balancing constraints are written as algebraic equations over complex variables and joint angular velocities. Using polynomial division, necessary and sufficient conditions for the balancing of planar four-bar linkages are derived. 相似文献
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Plücker's and Klein's equations provide an upper bound on the number of real inflections on the coupler curve of a hinged planar four-bar mechanism. Generally, for any configuration of the four-bar, the coupler points whose trajectories exhibit inflections lie on a circle. The coupler plane is partitioned by the envelope of the inflection circles into connected regions within which every coupler point has the same number of inflections on its trajectory. This enables us to locate coupler curves exhibiting the maximum possible number of inflections. 相似文献
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平面四杆机构近似导引综合的优化--混沌方法 总被引:16,自引:0,他引:16
将优化方法与混沌迭代算法相结合,以平面铰链四杆机构的近似导引综合为例,研究了平面连杆机构的近似导引综合问题的优化一混沌方法,得到了能近似实现给定运动条件的多个机构方案,使机构运动综合的多方案优选成为可能。 相似文献