Analysis of Graphical Approach for Cam Profile Determination (original) (raw)
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King Mongkut’s University of Technology North Bangkok International Journal of Applied Science and Technology, 2013
For controlling the precision of a manufacturing planar cam mechanism, one can base on a set of digital points measured on the manufactured cam profile by a coordinate measuring machine (CMM). Issued from this set of discrete digital points and by applying the well-known B-Spline least squares approach, one can reproduce the cam profile function. The given cam profile function and the theory of contact relations between cam and its follower enable us to deduce the displacement law of the follower and its derivatives. This paper presents a new method for reconstruction of a planar cam profile function from a set of digital points measuring on CMM machines, using B-Spline curve based on inverse subdivision method and theory of contact relations. An application to cam mechanism of oscillating follower with roller will be presented. To verify the feasibility and the accuracy of the proposed inverse subdivision method, a comparison between B-Spline least squares approach and inverse subdivision has been realized. The method possesses an acceptable accuracy and spends less time of calculation.
Mechanism and Machine Theory, 2004
This paper gives a comparison of two approximate analytical methods for determining disk cam profiles. The procedures are highly accurate for obtaining points on a cam with cylindrical followers. For both analytical procedures, the coordinates of the center of the follower are required at small increments of the cam angle. Both procedures can be easily programmed and depend only on the follower coordinates and not the follower type. A procedure for approximating the radius of curvature is also given.
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The requirement of high performance machinery demands efficient methods for design and manufacturing of Cams. Many authors used different techniques for improving design, machining and performance of Cams. Design of Cam still needs to be improved for better performance of mechanical systems. This paper reviews the past and present research work in the field of kinematic and dynamic aspect of design and optimization of Cam profiles. The basic curves and splines used to design the Cam profile by various researchers in past two decades have been discussed in this paper.
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The paper proposes a numerical method for computation of the base circle radius of cam mechanisms with translating flat-face follower as alternative to the traditional graphic-analytical method. The base circle radius is a very important data in the synthesis of the cam profile. The method uses two conditions: to keep the curvature continuously positive in all points along the cam profile and to avoid inflection or singularity points.
Graphical-analytical analysis of the mechanism with rotating cam and flat-face follower
MATEC Web of Conferences
The graphical-analytical methods are mentioned as being straightforward and expedite. The paper presents a graphical-analytical method for the kinematical analysis of a mechanism with rotating cam and oscillating flat-face follower. The manner supposes considering the contact point as a separate element of the mechanism and using concurrently the replacing mechanism with lower pairs and the actual mechanism, the relative motions from the contact point of the cam and contact point of the follower, respectively, are established. The methodology is exemplified for an actual case.
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International Journal of Advanced Trends in Computer Science and Engineering (IJATCSE), 2020
The article substantiates the construction of kinematic diagrams of motion of kinematic parameters of movement of a mechanism with an off-axis translationally moving pusher. The main tasks of displacements, speeds and accelerations of the pusher are given for a given mechanism scheme and cam profile. Plots of the speed of movement of the mechanism are constructed by the basic methods for constructing kinematic diagrams.
Modeling profile and kinematic analysis of two circular-arc cams
Engineering with Computers, 2012
The paper presents a methodology for modeling profile of two circular-arc cams, which is based on the application of homogeneous coordinate transformation method. Analytical expressions that allow complete determining of all design parameters and coordinates of all the points of two circular-arc cams profile are defined. Also, analytical expressions for determining the kinematic performance such as displacement, velocity, acceleration and jerk are derived. The defined methodology is applied on concrete examples for which the analysis of the kinematic performance is also performed. Additionally, it is shown that a proper choice of the design parameters can significantly affect the improvement of the kinematic performance, especially the reduction of jerk as one of the most unfavorable occurrences in these mechanisms. The given methodology allows very efficient determination of all input data for parametric modeling and production of two circular-arc cams on numerical machines. This approach allows the fulfillment of one of the most important requirements of modern production-reduction of time necessary for design and manufacturing which causes reduction of costs.
Analysis and Simulation of Cam Follower Mechanism Using Polynomial Cam Profile
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The cam follower mechanism is versatile and almost any arbitrarily-specified motion can be achieved. The use of algebraic polynomials to specify the follower motion is a new choice for cam profiles. This class of motion function is highly versatile especially in high speed automobiles. In the present work, kinematic and dynamic analyses of cam follower mechanism with polynomial cam profiles are carried out. The kinematic analysis presents follower displacement, velocity, and acceleration driven by a cam rotating at a uniform angular velocity. Dynamic analysis presents static and inertial forces developed in the mechanism. A 2-3 polynomial cam profile shows discontinuous follower acceleration at the ends of the stroke making it unsuitable at higher speeds. A 3-4-5 polynomial cam profile has an extended control as it provides a zero acceleration at the end points and no control over the follower jerks at end points. The modelling and simulation of a cam follower mechanism is performed...
Analytical Method for Synthesis of Cam Mechanism
Analytical method of the geometrical and kinematic synthesis used for the exact design of the profile of the Cam mechanism for desired movement program of slider-follower is presented. This method uses continues trajectory conditions in the points where path, velocity or acceleration starts-ends the changes. Usually the diagram of acceleration and maximal displacement of the slider are given or known. Based on desired or given conditions in this paper is described design of exact profile of the Cam mechanism. The method of continues trajectory, usually converts the problem of cam design in problem of solving the system of equations of unknown coefficients. For the simulations r esults we have use MathCad software.