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Yong Chang - One of the best experts on this subject based on the ideXlab platform.
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Design of the Disc Cam Profile with Negative Radius Translating Roller Follower
Applied Mechanics and Materials, 2013Co-Authors: Yong ChangAbstract:Abstract: This paper is to study the force-locking and shape-locking conjugate cam mechanisms. problems of the theoretical and actual contour of the cams with negative radius translation Roller Follower are solved by the use of "definite proportion and division point" method. The results could lead an important foundation for further research of the new type cam mechanisms.
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mechanical analysis of disc cam mechanisms with negative radius Roller translating Follower
Applied Mechanics and Materials, 2012Co-Authors: Rong Fu Lin, Yong ChangAbstract:This paper proposes the conditions of no-undercutting and contact-retaining of the disc cam mechanism with negative radius Roller Follower. Then, it presents the contact stress expression based on the mechanical analysis. In addition, the effects of different parameters on the force and contact stress are analysed. The results show that the contact stress can be reduced by designing the suitable parameters of the cam.
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Optimization Design of Disc Cam Mechanisms with an Offset Translating Negative Radius Roller Follower
Applied Mechanics and Materials, 2012Co-Authors: Rong Fu Lin, Yong ChangAbstract:The offset optimization is one of the key elements of designing cam mechanisms. This paper presents the mechanical model of a disc cam mechanism with an offset translating negative radius Roller Follower and deduces the efficiency expression. Then it proposes pressure angle and efficiency integration as the evaluation index of pressure angle and efficiency respectively. Furthermore, the optimal offset is derived according to the index. Finally, an example is provided to illustrate the method to obtaine the optimal offset.
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Second Mechanism Synthesis Task of Disc Cam Mechanisms with Roller Follower Moving in Planar General Motion
Journal of Mechanical Engineering, 2010Co-Authors: Yong ChangAbstract:Size synthesis about disc cam mechanisms with planar-general-motion Roller Follower are summarized as two kinds,then the accurate description of these mechanism synthesis tasks are concluded. The first mechanism synthesis task is solved by means of the concept of "virtual oscillating Follower". The universal thought,method and step of the second mechanism synthesis task are proposed by introducing a German high speed printing machine as an example. A set of analytical formulae of the determination of the "instantaneous nested interval" and the "whole nested interval" are proposed firstly by the coordinate establishment,the "floating number axis" and the division of work travel. The existence and its analytical criterion of these formulae are proposed,and then the method to determinate the allowable area for Roller center and the value range of the cam's base circle radius are obtained. A mechanism synthesis example is displayed.
Louay S. Yousuf - One of the best experts on this subject based on the ideXlab platform.
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Nonlinear dynamics behavior of cam-Follower system using concave curvatures profile:
Advances in Mechanical Engineering, 2020Co-Authors: Louay S. Yousuf, Dan B. MarghituAbstract:Nonlinear dynamics behavior of the Roller Follower is discussed for different Follower guides’ internal dimensions and cam angular speeds. A dynamic tool such as Wolf algorithm is used to extract l...
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Analytic and numerical results of a disc cam bending with a Roller Follower
SN Applied Sciences, 2020Co-Authors: Louay S. Yousuf, Dan B. MarghituAbstract:The bending deflection of a disc cam with a Roller Follower was analyzed by using constant angular velocity of the cam. The objective of this paper was to study the effect of the contact load on the bending deflection of the cam profile. Numerical simulations were carried out using SolidWorks and ANSYS Ver. 19.2 package based on finite element analysis. SolidWorks was used to determine the dynamic response of the Follower, while the bending deflection of the cam profile has been investigated using ANSYS package. The modal and harmonic analyses were used to find the natural frequency and the dynamic response of the bending deflection. The theory of circular plate was applied to derive the analytic solution for the bending deflection. The experiment data has been collected with an infrared camera system. The dynamic response of the Follower, at the point of contact, was verified analytically and experimentally. The reduction rate for bending deflection is (73.425%) for path no. (1), (85.925%) for path no. (2), and (61.467%) for path no. (3). The harmonic amplitude peak of the point (18) on the nose (2) is bigger than the peak of the point (4) on the nose (1) because of large values for the radius of curvature of the nose (2).
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Nonlinear Dynamics Behavior of a Pear Cam With Roller Follower Mechanism
Volume 4: Dynamics Vibration and Control, 2019Co-Authors: Louay S. Yousuf, Dan B. MarghituAbstract:Abstract A pear cam and Roller Follower system is studied for distinct values of cam rotational speeds. Different values of clearance (C = 1, 1.5, and 2 mm) are used. SolidWorks is used for the numerical analysis. The largest Lyapunov exponent was calculated for the mechanism and the non-periodic motion is analyzed for different clearances and angular speeds. The displacement of Follower motion is processed using OPTOTRAK / 3020 with a 3-D infrared sensor experimentally. The system with clearance C = 2 mm has largest value of (LLE) at N = 400 rpm, while the lowest value of (LLE) is at N = 100 rpm at the same value of angular speed.
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Experimental and simulation investigation of nonlinear dynamic behavior of a polydyne cam and Roller Follower mechanism
Mechanical Systems and Signal Processing, 2019Co-Authors: Louay S. YousufAbstract:Abstract In this study a polydyne cam and a Roller Follower with different cam rotational speeds are analyzed. The chaos has been investigated based on positive Lyapunov exponent value. The effect of Follower guide’s clearance on chaos is considered. The contact between cam and Follower is simulated by using Solidworks program. The power spectrum of Fast Fourier Transform and phase plane have been examined the Follower non-periodicity during Follower motion in the y-direction. Rosenstein program is used to calculate largest Lyapunov exponent. The experimental setup has been implemented by using OPTOTRAK/3020 through a 3-D infrared markers to track Follower motion. The signal of Follower motion in the y-direction has been processed depend upon data acquisition technique. The system with Follower guide’s clearance C = 2 mm is more chaotic than the others at cam rotational speed N = 800 rpm and N = 1200 rpm. The simulation and experimental results are compared and verified for largest Lyapunov exponent.
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Nonlinear Dynamic Analysis of a Polydyne Cam With Translated Roller Follower Mechanism With Clearance
Volume 2: Control and Optimization of Connected and Automated Ground Vehicles; Dynamic Systems and Control Education; Dynamics and Control of Renewabl, 2018Co-Authors: Louay S. Yousuf, Anis DriraAbstract:In this paper, a polydyne cam with translated Roller Follower over a range of speeds are analyzed. There is a clearance between the Follower and the guide. The dynamic simulation is investigated taking into account the impact and the friction. The simulation has been done by using Solidworks program. The effect of Follower guides’ clearances on Roller Follower non-periodicity is considered based on Lyapunov exponent technique. Rosenstein method is used to calculate largest Lyapunov exponent for different angular velocities of the cam. The experimental setup has been implemented by using OPTOTRAK/3020 through a 3-D infrared markers to track Follower motion. The power spectrum analysis of Fast Fourier Transform and phase plane contour are examined Roller Follower non-periodicity.
Chang Wen-tung - One of the best experts on this subject based on the ideXlab platform.
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Computerized tolerance analysis of disk cam mechanisms with a Roller Follower
Springer Verlag, 2010Co-Authors: Chang Wen-tungAbstract:[[abstract]]The tolerance analysis is one of the key elements of design and manufacturing of cam mechanisms. This paper presents a computerized method for analyzing the tolerances in disk cam mechanisms with a Roller Follower. By employing the concept of simulated higher-pair contact analysis, the kinematic deviation of the Follower motion arising from the tolerance amount of each design parameter can be determined numerically. The offset translating Roller Follower and the oscillating Roller Follower cases are given to illustrate the proposed method. The tolerance analysis results show that, owing to the combined effects of various design parameters, the position accuracy of the Follower motion may degrade considerably. But, the tolerance amounts of the design parameters may also have a compensating effect to enhance the relative accuracy of the Follower motion between its high and low dwell positions. Hence, it is possible to find the optimal tolerance combination for balancing the kinematic accuracy and the tolerance amounts of disk cam mechanisms with a Roller Follower.[[fileno]]2020209010025[[department]]動機
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Inspecting profile deviations of conjugate disk cams by a rapid indirect method
Elsevier, 2010Co-Authors: Chang Wen-tungAbstract:[[abstract]]A rapid indirect method for inspecting profile deviations of conjugate disk cams is proposed. For a conjugate cam mechanism with an oscillating Roller Follower, if the center distance between the cam and the Follower pivots is changed to be variable, when the cams rotate, the variation of the center distance may indicate the profile errors. Equations relating the center distance variation with the cam profile errors are derived. The method was verified by actually measuring a pair of conjugate cams. (C) 2009 Elsevier Ltd. All rights reserved.[[fileno]]2020209010024[[department]]動機
Shivam S. Alakhramsing - One of the best experts on this subject based on the ideXlab platform.
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lubrication and frictional analysis of cam Roller Follower mechanisms
Proceedings of the Institution of Mechanical Engineers Part J: Journal of Engineering Tribology, 2018Co-Authors: Shivam S. Alakhramsing, M.b. De Rooij, Dirk J. Schipper, M. Van DrogenAbstract:In this work, a full numerical solution to the cam–Roller Follower-lubricated contact is provided. The general framework of this model is based on a model describing the kinematics, a finite length line contact isothermal-EHL model for the cam–Roller contact and a semi-analytical lubrication model for the Roller–pin bearing. These models are interlinked via an improved Roller–pin friction model. For the numerical study, a cam–Roller Follower pair, as part of the fuel injection system in Diesel engines, was analyzed. The results, including the evolution of power losses, minimum film thickness and maximum pressures, are compared with analytical solutions corresponding to infinite line contact models. The main findings of this work are that for accurate prediction of crucial performance indicators such as minimum film thickness, maximum pressure and power losses a finite length line contact analysis is necessary due to non-typical EHL characteristics of the pressure and film thickness distributions. Furtherm...
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A full numerical solution to the coupled cam-Roller and Roller-pin contact in heavily loaded com-Roller Follower mechanisms
Proceedings of the Institution of Mechanical Engineers Part J: Journal of Engineering Tribology, 2017Co-Authors: Shivam S. Alakhramsing, Dirk J. Schipper, Matthijn De Rooij, Mark Van DrogenAbstract:In cam–Roller Follower units two lubricated contacts may be distinguished, namely the cam–Roller contact and Roller–pin contact. The former is a nonconformal contact while the latter is conformal c...
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Lubrication and frictional analysis of cam–Roller Follower mechanisms:
Proceedings of the Institution of Mechanical Engineers Part J: Journal of Engineering Tribology, 2017Co-Authors: Shivam S. Alakhramsing, M.b. De Rooij, Dirk J. Schipper, M. Van DrogenAbstract:In this work, a full numerical solution to the cam–Roller Follower-lubricated contact is provided. The general framework of this model is based on a model describing the kinematics, a finite length line contact isothermal-EHL model for the cam–Roller contact and a semi-analytical lubrication model for the Roller–pin bearing. These models are interlinked via an improved Roller–pin friction model. For the numerical study, a cam–Roller Follower pair, as part of the fuel injection system in Diesel engines, was analyzed. The results, including the evolution of power losses, minimum film thickness and maximum pressures, are compared with analytical solutions corresponding to infinite line contact models. The main findings of this work are that for accurate prediction of crucial performance indicators such as minimum film thickness, maximum pressure and power losses a finite length line contact analysis is necessary due to non-typical EHL characteristics of the pressure and film thickness distributions. Furtherm...
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Towards a fundamental understanding of the tribological behaviour of cam-Roller Follower contacts
1Co-Authors: Shivam S. AlakhramsingAbstract:Cam-Roller Followers are part of the valve train mechanisms found in internal combustion engines. Valve train friction losses may contribute up to 10% of the total engine friction losses. The lubricated cam-Roller Follower unit consists of two lubricated contacts, namely the cam-Roller contact and Roller-pin contact. While the former is a non-conformal contact, the latter is a conformal contact. The traction induced by the cam-Roller contact drives the Roller. It is important to study friction between the cam and Roller as it influences the engine efficiency and the onset of wear – and thus ultimately lifetime – of components. Understanding lubrication conditions in the cam-Roller contact is complicated due to transient variations of the geometry, force and friction in the Roller-pin contact. A very important variable, affecting the cam-Roller lubrication performance, is the frictional force (which resists the motion of the Roller) at the Roller-pin contact. The lubricated cam-Roller contact studied in this thesis is highly loaded with contact forces up to 16 kN. Important lubrication performance indicators of the cam-Roller contact are the pressure, film thickness and frictional force. This thesis focuses on the factors influencing the aforementioned lubrication performance indicators. Relying on the aforementioned, the factors studied in this work are: •The influence of axial shape of the Roller: The axial shape of the Roller and its influence on the generated film thickness, pressure and friction in the cam-Roller contact. This was done by means of a smooth surface finite element method (FEM)-based finite line contact elastohydrodynamic lubrication (EHL) model. The model shows the effects of parameters describing the axial shape of the Roller, velocity, load and material properties on the lubrication performance indicators. •The influence of elastic deformation in the Roller-pin contact: In order to better quantify the friction, film thickness and pressure in the Roller-pin contact a similar smooth surface FEM-based EHL model was developed for the Roller-pin contact. The model demonstrates the importance of allowing for elastic deformation of the conformal Roller-pin contact and its effect on film thickness, pressure and friction coefficient. •The influence of Roller-pin contact friction in the high slide-to-roll ratio (SRR) domain of the cam-Roller contact: At increasing levels of friction in the Roller-pin contact the amount of sliding at the cam-Roller contact increases, in turn affecting the film thickness, pressure and cam-Roller contact friction coefficient. In order to analyse the effects of higher values of Roller-pin friction coefficient on the cam-Roller lubrication performance, an infinite line contact mixed-thermo-elastohydrodynamic (TEHL) model was developed for the cam-Roller contact. The mixed-lubrication model is based on the load-sharing concept and uses real surface roughness measurement data as input. The complete model is based on a smooth surface FEM-based EHL line contact model and a boundary element method (BEM)-based dry rough normal contact solver. The model exposes the influence of Roller-pin friction coefficient on non-Newtonian, thermal and surface roughness effects in the cam-Roller contact. •The influence of Roller-pin contact friction in the low SRR domain of the cam-Roller contact: In order to improve mixed friction predictions under low sliding velocities, the dependence of boundary layer friction on sliding velocity was incorporated into the previously developed infinite line contact mixed lubrication model. This was done by means of a BEM-based dry rough tangential contact solver which was added to the previously developed model. The model shows how the shear stress-slip relationship influences the macroscopic frictional force in the cam-Roller contact, under low sliding velocity operating conditions.
Li Yanping - One of the best experts on this subject based on the ideXlab platform.
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Size synthesis method for disc cam mechanisms with a negative radius translating Roller Follower
Proceedings of the Institution of Mechanical Engineers Part C: Journal of Mechanical Engineering Science, 2016Co-Authors: Chang Yong, Wu Qiuping, Li YanpingAbstract:This work considers a disc cam mechanism with an upright installed negative radius translating Roller Follower. Accurate descriptions, as well as the basic concept and steps, are given for the shap...
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Research on the General Second Mechanisms Synthesis Task of Disc Cam Mechanisms with Roller Follower Moving in General Planar Motion
Journal of Mechanical Engineering, 2012Co-Authors: Li YanpingAbstract:To cam mechanisms with Roller Follower moving in general planar motion,the concepts of "special and general type II mechanisms synthesis tasks" are put forward,and the scientific and exact description is brought.Via establishment of coordinate system,introduction of "floating coordinate system" and division of front and rear work travel,especially the introductions of new concepts of "instantaneous choice area" and "whole choice area",the new graphic fundamental for solving "instantaneous choice area" of Roller-center as well as deep analysis of boundary are brought out.The concepts of "most commercial search belt-area" and important thinking of eqisdistance-dispersion are given.Dimensionality-drop rapid solving algorithm is given,which satisfactorily solves "general type II mechanisms synthesis task".
