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本文论证了凸轮从动件的位移与其加速度曲线之间的“面积矩”关系。为了调整以数值方式给出的加速度曲线,本文提出了“附加曲线”法。运用上述的关系和方法,能够解决下述问题,使凸轮从动件的位移、速度、加速度和跳跃度在区间始末两处能精确地符合给出的数据,而且,能够直接控制加速度曲线的形状和最大值。最后给出了胶印机递纸构件在一个区间内加度曲线的设计过程。 相似文献
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滚子从动件盘形凸轮机构的运动分析 总被引:4,自引:0,他引:4
针对滚子从动件盘形凸轮机构,根据凸轮机构运动简图和凸轮实际廓线测量值,导出了确定从动件的位移、速度、加速度及其机构压力角的计算公式,并用实例验证了计算公式的正确性。 相似文献
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The meaning of kinetothermal analysis and synthesis of mechanisms is defined. Using kinetothermal analysis and synthesis, an analytical technique is developed to describe and compensate for the kinetothermal errors in displacement, velocity and acceleration in cam-follower systems. The class of problems considered includes the case where either a cam, follower or framework is subjected to a different uniform temperature than the other two and the case where a cam, follower or frame expand differently in a uniform temperature change due to unequal coefficients of thermal expansion. An example application is presented. 相似文献
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徐超 《中国制造业信息化》2001,30(3):24-25
同速点法是机构运动分析图解法中一种非常重要的方法 ,利用它对某些平面机构 ,特别是平面高副机构进行速度分析及角速度分析是非常方便和直观的 ,但一般认为利用这种方法不便或不能求解加速度或角加速度问题。通过对凸轮机构从动件加速度的理论分析及假想机构的构造、假想机构的运动分析 ,介绍了应用同速点法求解凸轮机构从动件加速度的方法 ,使用这种方法可避免一般向量多边形法繁琐的求解过程 ,具有应用方便的特点 相似文献
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By employing the concept of equivalent linkage, this paper presents an analytical method for analyzing the mechanical errors
of disk cam mechanisms with a flat-faced follower. The resulting error equations do not really involve the location of the
curvature center of the cam profile, and locating the curvature center of the cam profile is not essential. The resulting
errors are significantly affected by the pressure angle, and the smaller pressure angle will result in the smaller mechanical
error. In the worst case, owing to the joined effects of various design parameters, the accuracy of the follower motion may
degrade considerably. For the oscillating follower case, all acceleration error functions have a sudden change at every beginning
and at every end of the motion even though the theoretical follower displacement is cycloidal motion. 相似文献
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The problem of this paper is the high contact stress at the point of contact between the cam and the follower.A pear cam and roller follower mechanism were studied and analyzed for different position of the follower and different contact compression load.The objective of this paper is to study the effect of contact compression load on the contact stress distribution of the cam profile at the point of contact.Four different positions of the follower with the cam was considered(0°,90°,180°,and 270°).The theory of circular plate was applied to derive the analytic solution of the contact stress.The numerical simulation had been done using ANSYS Ver.19.2 package to determine the contact stress,while SolidWorks software was used to investigate follower displacement,velocity,and acceleration.Four distinct values of the compression contact load,such as 3.121 N,6.242 N,9.364 N,and 12.485 N,were used in the numerical simulation.In the experiment setup,a photo-elastic technique was carried out in the field of polarized light to exhibit the stress distribution on the cam specimen.The annealed PSM-4 backalate material was used in the experiment setup.The experimental value of contact stress was checked and verified analytically and numerically at the point of contact.The innovation in this paper the use of spring-damper system which reduce the value of contact stress at the point of contact.The contact stress was maximum 2.136 MPa when the follower located at 270° with the cam,while the contact stress was minimum 1.802 MPa when the follower located at 180°at compression load 12.485 N. 相似文献
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高速凸轮机构的动态设计 总被引:5,自引:0,他引:5
张春红 《机械工程与自动化》2006,(2):143-144,151
建立了高速凸轮机构的动力学模型及其运动方程式.对具有摆线运动规律的从动件进行了动态响应的分析,并对凸轮机构进行动力学仿真,分析了从动件作用在凸轮上的作用力。为设计人员设计凸轮机构提供了一定的设计依据。 相似文献
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A general procedure for determining the equivalent radius of curvature and entraining velocity of various oscillating and reciprocating cam and follower mechanisms has been developed. This procedure requires as input the motion of the follower, i.e., the lift curve, the angular velocity of the cam and the basic geometry of the cam and follower mechanism. The radius of curvature of the cam at the point of contact was determined using the method of kinematic coefficients. A vector loop superimposed on the cam and follower was used to determine the entraining velocity of the mechanism at the point of contact. 相似文献
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研究了摆动滚子从动件凸轮机构的加工与从动件位移误差之间的关系。推导出了从动件位移误差计算公式,该公式可用于分析计算从动件位移误差。指出了合理选定凸轮机构的参数和加工精度。可减小从动件位移误差,提高摆动滚子从动件凸轮机构的运动精度。 相似文献
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The design Procedure described in this paper consists of:
1, Selection of a virtual acceleration curve represented by a series of numerical values ( α mm) with arbitrarily presc-ibed shape according to working requirements of the cam follower;
2, Selection of incremental cam angle according to the desired and attainable accuracy of contour fabrication;
3, adjustment of the above virtual curve so that it will satisfy certain given requirements or boundary conditions of the follower during its stroke. Various follower boundary conditions are grouped into four classes. For each class an equation for adjustment is derived;
4, Calculation of the unknown scale factorαa mm/s=/mm(actual acceleration A in mm/s2 =μaα) and the required cam profile by substituting in a set of equations derived for each class of boundary conditions A historical review about this topic and an example for approving design formulas are placed at the beginning and ending of this paper. 相似文献
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This paper describes a computer-aided design and manufacturing system for the design and production of complex profiles for
high-performance drum cams within the specified tolerance. The system graphically generates the cam profile on the cylindrical
drum after performing an analysis of the kinematic performance for the prescribed follower motion, using a B-spline representation
of follower curves. Eight different types of follower motion for a translating follower are considered. The kinematic performance
is based on the criteria of achieving the lowest levels of velocity and acceleration for each curve. The system is also able
to simulate the motion of the designed cam graphically. The system also recommends the best cam profile on the basis of comparing
the kinematic performance of all the B-spline representations of all the follower motions. 相似文献
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David D. Ardayfio 《Mechanism and Machine Theory》1980,15(1):1-4
The Kinetothermoelastodynamic (KITED) model used is a single degree-of-freedom flexible cam-follower system in which the unconstrained thermal distortion of the cam is considered. The synthesis equation for the cam profile is derived for a prescribed follower acceleration in either analytical or numerical form. The technique is demonstrated by numerical examples. 相似文献
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弧面分度凸轮机构动力学建模与Simulink仿真技术的研究 总被引:1,自引:0,他引:1
对弧面分度凸轮机构动力学特性进行了研究,考虑间隙存在、柔性轴和电机特性下,建立了系统动力学方程,应用Matlab/Simulink求解和动态仿真。结果显示间隙对凸轮和工作盘的响应有影响,从动件最大角加速度提高28%,电机输出轴角速度高频振荡。 相似文献