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1
Gregerson, David Lee. "An investigation of chaos in a single-degree-of-freedom slider-crank mechanism." Thesis, Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/16805.
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Mauntler, Nathan A. "Kinematic and dynamic behavior of a wearing joint in a crank-slider mechanism." [Gainesville, Fla.] : University of Florida, 2009. http://purl.fcla.edu/fcla/etd/UFE0024958.
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Ong, Chin Guan. "Shaking and Balance of a Convertible One- and Two-Cylinder Reciprocating Compressor." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/31433.
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This research involves the study of a one- and two-cylinder convertible reciprocating Freon compressor for air conditioning or refrigeration purposes. The main concern is the reduction of the vibration (noise) caused during the operation of the compressor. Vibration is a main concern when the compressor is shifted from the one-cylinder operation to the two-cylinder operation mode and the reverse of this shift.
The objectives for this research are (1) to investigate the shaking force due to the reciprocating mass at high frequencies, which are up to 4600 Hz (80w) in this research; (2) to determine the dominant force for compressor vibration among the three possible sources of shaking force due to reciprocating mass, impact forces due to clearance at the connecting rod - piston joint, and the z-axis force from the motor torque due to the rotor's conductor rods being skewed at an angle; (3) to minimize the difference in change of kinetic energies when switching between the one- and two-cylinder operating modes of the compressor.
The properties of the vibration in one- and two-cylinder operation have been studied and results have been analyzed in terms of kinetic energies generated in different setting of operation of the compressor. Dynamic simulation for the impact force is computed using SIMULINK. The Z-axis force due to the motor is computed. Results indicated that shaking force due to the reciprocating mass is the dominant force for only the first two harmonics (w, 2w). An optimization routine based on Hooke and Jeeves pattern search method is developed and an optimized setting of angle, force, and torque for balancing of the crankshaft to achieve objective (3) is determined.Master of Science
4
Avanço, Rafael Henrique. "Análise da dinâmica não-linear de pêndulos com excitação paramétrica por um mecanismo biela-manivela." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/18/18149/tde-27052015-113137/.
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O presente trabalho trata da análise da dinâmica de um pêndulo simples excitado em seu suporte por um mecanismo biela-manivela de forma ideal e não-ideal. No caso ideal, verifica-se que o resultado da excitação por este tipo de mecanismo se aproxima do resultado da excitação harmônica de suporte do pêndulo quando o raio da manivela é suficientemente pequeno em comparação com o comprimento da biela. A equação diferencial do sistema é resolvida numericamente e resultados do comportamento pendular são obtidos através de mapas de fase, histórico no tempo e seções de Poincaré. Expoentes de Lyapunov são, também, obtidos para a análise de casos caóticos posteriormente comparados com diagramas de bifurcação. Bacias de atração são desenhadas para os resultados estáveis do pêndulo: oscilatórios ou rotativos. Os resultados obtidos para a excitação por biela-manivela são dos mesmos tipos de movimento observados no caso do pêndulo excitado harmonicamente no suporte, entre eles: ponto fixo, oscilação, rotação pura, oscilação-rotação e o caos. Para a frequência de ressonância principal observam-se resultados caóticos em faixas mais largas de amplitude quando o raio de manivela se aproxima do comprimento da biela. Em frequências ressonantes menores nenhuma relação desse tipo pôde ser estabelecida. Uma análise utilizando o mesmo mecanismo é também feita com excitação por potência limitada de um motor elétrico linear de corrente contínua onde se investigou o efeito de feedback dado pelo pêndulo sobre o motor. Esses resultados são comparados com o caso ideal com a manivela acionada com rotação constante. Observa-se uma supressão do caos no caso não-ideal em casos de menor potência no motor. Entretanto, quando a potência de motor é maior, o modelo ideal coincide com o não-ideal.In this analysis it was studied the dynamics of a simple pendulum excited by a crank-shaft-slider mechanism in the support ideally and non-ideally. In the ideal case, it was verified the result for an excitation by a crank-shaft-slider approaches to the result of the harmonically excited pendulum when the radius of the crank is sufficiently small in comparison with the length of the shaft. The resultant differential equation is solved numerically and the results of pendulum behavior are obtained by phase portraits, time histories and Poincaré sections. It is also calculated the Lyapunov exponents for the chaotic cases in analysis and a comparison is performed with bifurcation diagrams in the same regions. Basins of attractions are plotted for stable results like oscillatory and rotational solutions. In the results observed for the crank-shaft-slider excitation there are kinds of motion similar to those observed in the harmonic excitation: fixed points, oscillation, pure rotations, oscillation-rotations and chaos. However, in the principal resonance zone, chaotic results were more frequent when the radius of crank approaches the shaft length. A brief analysis is done concerning the same mechanism, but considering the excitation by limited power supply of a linear DC motor. In the sequence it is checked the feedback effect from the pendulum over the motor and comparison with the respective ideal excitation is accomplished where differences are commonly observed. With greater power the ideal model coincides with the nonideal model. In cases of lower power, the two models diverge in the results.
5
Biječek, Tomáš. "Deformačně-napjatostní analýza ojnice spalovacího motoru pomocí MKP." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-228164.
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In this diploma thesis is completed the FEM analysis of connecting rod in combustion engine Briggs & Stratton of the garden lawnmower. Within the frame of computing in the FEM system ANSYS Workbench is solved static structural strein and stress analysis, buckling analysis a fatigue also. The boundary conditions for FEM computing come out from the kinematic and dynamic analysis of the crank-slider mechanism in combustion engine. The 3-D models of the crank-slider mechanism are created in parametric SolidWorks modeller. Own construction variants of the connecting rod based on results of FEM analysis are also designed.
6
CHEN, YIN-QUAN, and 陳盈全. "Shaking force balancing design of slider-crank mechanism." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/36275757208701209620.
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LEE, HSIN HU, and 李新護. "Application of Slider – Crank Mechanism in Lifting a Weight." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/40370419861161764109.
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碩士國立雲林科技大學
機械工程系
104
Abstract In this study, the application of slider – crank mechanism in lifting a weight is discussed. During the mechanism design stage, the effects of significant factors on mechanical performance should be studied. By computer aided software and mechanism theory, the mechanical behaviors can be predicted in advance to improve the design accuracy. The position, velocity, and acceleration analysis of each link are performed to predict the mechanism behavior of the slider-crank system. Then the dynamical analysis is carried out to solve the reaction force and torque on each link. The required horse power of motor can be estimated by the driving force. The feasible procedures to design a mechanism system is proposed to solve several practical problems.
8
邱勝琳. "Design of Nonlinear Controllers for A Montor-Slider-Crank Mechanism." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/01692059537589140202.
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碩士中原大學
電機工程學系
85
The object of this thesis is to design nonlinear controllers for the slider-crank mechanism, which is driven by a permanent magnet (PM) synchronous servo motor. First, the dynamic equation of motion of the motor-slider-crank coupled system is derived by Hamilton's principle and Lagrange multiplier method. Then, an adaptive controller and a sliding mode controller are designed to enhance the robustness of the coupled system with regard to external load disturbance and plant parameter variations. Finally, numerical simulation and experimental results are presented to show that the proposed nonlinear controllers are suitable to apply in the motor-slider-crarik coupled system with good tracking performance.
9
Pham, Thanh-Thuan, and 范成順. "Optimal Design and Manufacture of a Compliant Crank-Slider Mechanism." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/k62e75.
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碩士國立高雄應用科技大學
機械與精密工程研究所
102
A compliant mechanism achieves its movement via the expansion of flexible segments or the distortion of one portion of the materials employed. However, repeating the deformation of materials in compliant mechanisms causes a serious problem that has not been considered in previous work. A number of viable configurations were investigated herein, based on the Finite Element Method to carry out the comparison of convergence stress on each model, in order to select one configuration. The comparison technique is then combined with optimization to obtain the configuration with improved performance. From this configuration, a prototype was generated and tested. The testing result showed that the compliant crank-slider mechanism indicated displacement, as well as characteristics similar to the model prediction. This thesis offers directions for further work by incorporating a compliant crank-slider mechanism into electrical contacts called constant-force electrical contacts.
10
Feng, Chien-Sen, and 馮建森. "Dynamic Analysis and Control of a Spatial Slider-Crank Mechanism." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/52066847461711889313.
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碩士國立高雄第一科技大學
機械與自動化工程所
91
The kinematic and dynamic formulations of a spatial slider-crank mechanism shall be redefined by simply geometric constraints in this study. The governing equations, formulated by the Hamilton principle and partitioning method, include effects of mass, external force, reducing gear box and motor electric input. In order to verify the perfection of geometric modeling, the simulated software-MSC. VisualNastran 4D is adopted in contrast with the numerical analysis of kinematics. Furthermore, the integral variable structure control (IVSC) is employed to execute the velocity and position controls. Numerical results show that the accuracy of kinematic analysis, and the good performance of IVSC robust against to the parameter variation and external disturbance.
11
Chen, Shin-Jen, and 陳信任. "Kinematic and Dynamic Analysis of an Intermittent Slider-Crank Mechanism." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/13513295629946190393.
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碩士中原大學
機械工程研究所
89
This paper investigates kinematic and dynamic analyses of an intermittent slider-crank mechanism which consists of four parts: crank, pneumatic cylinder, slider and two stops at both ends of the stroke. When the crank rotates continuously, the slider contacts with the stops and the pneumatic cylinder is compressed or extended. Meanwhile, a manipulator attached at the slider can operate upward or downward. The motions of the intermittent slider-crank mechanism could be divided into three stages, and be formulated by Hamilton’s principle. In order to compare the operating performance of the motor-mechanism coupled system, the PM synchronous servomotor with the integral variable structure control (IVSC) and separately excited DC motor taken as actuators are investigated. Finally, by using Runge-Kutta method, the transient amplitudes are obtained and compared with the traditional slider-crank mechanism.
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CHEN, GUAN-ZHOU, and 陳冠州. "The dynamic analysis of a slider-crank mechanism with bearing clearance." Thesis, 1988. http://ndltd.ncl.edu.tw/handle/35622564981690539655.
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Chen, Hsin-Hung, and 陳信宏. "Vibration Analysis of a Slider-Crank Mechanism by Finite Element Method." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/75291383041246885369.
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碩士中原大學
機械工程研究所
82
In this thesis, the vibration analysis of slider-crank mecha- nism with a flexible connecting rod is studied. The equations of motion of Timoshenko beam and its corresponding boundary conditi- ons are developed by Hamilton's principle, which are transformed into a set of ordinary differential equations by using of finite element method. The realistic operation condition is that the cr- ank rotates, and the end of connecting rod moves reciprocally wi- th slider along the horizontal guide.The geometric constraint of the end of connecting rod is derived and introduced into the equ- ations of motion and boundary conditons. It is found that the bo- undary condition of the connecting rod moving with slider is the moving boundary supports, but not the simply supported ones assu- med in all references. Finally, the Runge-Kutta numerical method is applied to obtain the transient amplitudes which are compared with those of considering the flexible rod to be Euler beam or assuming the ends of connecting rod to be simply supported. Fur- thermore, the harmonic balance method is used to obtain the steaty-state solutions of the system.
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Tsai, Sheng-Hsun, and 蔡昇勳. "Dynamic Analysis and Balancing of Planar Slider-Crank Mechanism with Clearances." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/17905216864631009359.
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Tzou, Vincent, and 鄒文崧. "On the Balance and Application of Slider-Crank Mechanism and Multi-Cylinder Engines." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/62163932357816572231.
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碩士長庚大學
機械工程研究所
87
ABSTRACT The purpose of this paper is to investigate the balance and application of slider-crank mechanism and multi-cylinder engines. At first, the shaking force and shaking moment of slider-crank mechanism and multi-cylinder engines are derived. Then, the balance of multi-cylinder engines is investigated and discussed. Furthermore, the dynamic force analysis of slider-crank mechanism for press is performed for different eccentricities and gravity force directions, and the optimum transmission angle of working stroke is obtained by optimization. Finally, the coupler point of gear-slider-crank mechanism that can generate the elliptical or straight-line coupler curves is derived and animated. The result of this paper is benefit to the design of slider-crank mechanism and its applications, such as engines, compressors, presses, and other automation machines etc.
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Lin, Jyh-Yao, and 林寘堯. "Dynamic Analysis of Slider-Crank Mechanism with a Crack in the Flexible Linkage." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/71157287853783676720.
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碩士國立成功大學
航空太空工程學系碩博士班
93
In this thesis, the dynamic behavior of slider-crank mechanism with a crack in the flexible linkage is studied. The crank of the system is assumed to be rigid and the flexible linkage is modeled as a Timoshenko beam. The crack in the flexible linkage is modeled as a transverse open crack whose local flexibilities are calculated by using a fracture mechanics approach and the Castigliano’s theorem. The finite element method and Hamiltion’s principle are employed to derive the equations of motion of the system. Dynamic responses are obtained by using the Runge-Kutta method. Influences on dynamic response of the system due to different depths and locations of the crack on flexible linkage are investigated.
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Chian-HaoYang and 楊虔豪. "Kinematic and Dynamic Characteristics Design of a Compound Variable-Speed Mechanism with Slider-Crank and Screw Mechanisms." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/13657260439799025200.
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碩士國立成功大學
機械工程學系
102
Traditionally, a designer assumes a constant input to design the output characteristics of the target mechanism. Based on such an assumption, if the required outputs are different, the dimensions of the mechanism should be redesigned. An alternative approach of achieving this goal without modifying the geometric dimensions of the mechanism is to design the mechanism with a variable input speed. This research uses such a design concept to improve the kinematic and dynamic characteristics of a slider-crank mechanism, a screw mechanism, and their compound mechanism. Multi-objective optimization methods Firstly, the equations for analysing the kinematic and dynamic characteristics are derived. Then, a variable input speed function is designed along with applying multi-objective optimization methods to improve the output characteristics of the slider-crank mechanism, screw mechanism, and compound mechanism. The study also establishes a servo control device for controlling a servo motor to generate the desired input speed function for driving the three interested mechanisms. Furthermore, a device for measuring the output characteristics is used to verify the feasibility of the proposed theory. The study shows that the Bezier curve is suitable for designing the variable input speed function to improve the output characteristics without modifying the dimensions of the interested mechanisms. Furthermore, the results of the compound mechanism show that the slider-crank mechanism can provide an equal input motion both in positive and negative directions of the motor. In addition, the experimental results are close to the theoretic values. This proves the feasibility of the proposed design approach.
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Chen, Chan-Yao, and 陳展耀. "On the Design of the Motion and Dynamic Characteristics of a Slider-Crank Mechanism." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/96619860476168395691.
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碩士崑山科技大學
機械工程研究所
99
Slider-crank mechanisms are widely used for industrial equipment. If the dynamic balance is designed for a machine, then the operational condition will be more stable. In general, the dynamic balance design methods are weight balance techniques, but these techniques will increase the weight and applied load of the desired machine. The purpose of this work is to use the vector loop and speed function design approaches for improving the motion and dynamic (shaking force and shaking moment) characteristics. First, we analyze the motion and dynamic characteristics of a given slider-crank mechanism. Secondly, we design a continuous speed function and chose the design parameters of the design function for improving the motion and dynamic characteristics.
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ZHOU, JIA-HONG, and 周佳宏. "Dynamic stability of a high-speed slider-crank mechanism with a flexible connecing rod." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/63605957240758231261.
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Lin, Kwei-Wei, and 林魁偉. "Vibration Analysis of the Cracked and Flexible Connecting Rod in a Crank-Slider Mechanism." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/52253783906746844288.
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碩士中原大學
機械工程研究所
89
Abstract Considering a crank-slider mechanism, the analysis of the longitudinal and transverse vibration of the cracked flexible connecting rod is analyzed in this study. First of all, the connecting rod is assumed as the Euler’s beam, then the equations of motion and boundary conditions are derived by using Hamilton’s principle. Moreover, by using the Galerkin method with mode shape function that satisfies the boundary conditions, the equations of motion are reduced to the Mathieu equations. And then, Runge-Kutta method is employed to determine the transient amplitude, some parameters, such as the ratio ( ) of rotating angular velocity of the crank to natural frequency of transverse vibration for the link without crack, the ratio ( ) of the crank length to connecting rod length, and the ratio (a / R) of crack depth to radius of link, influence the amplitude. The results reveal that the natural frequency of connecting rod is not influenced by the angular velocity. While the ratio of the crank length to connecting rod length increases, the transient transverse amplitude increases, too. The ratio of crack depth increases, the transverse amplitude increases a little.
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Shoou-Chin, Chang, and 張守欽. "A Study of the Identification of the Slider-Crank Mechanism and the Variable Lead Screw Mechanism with Steady Periodic Motions." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/87042811066419425178.
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碩士國立成功大學
機械工程學系
87
The slider-crank mechanism (hereinafter SCM) and the variable lead screw mechanism (hereinafter VLSM) are used in various machinery, such as the shuttleless weaving looms. But the frictional dissipation between the slider and the guide (hereinafter SG), and between the screw and the meshing elements (hereinafter SME), is difficult to measure. For investigating the dynamic characteristics of the mechanisms accurately, system identification is applied on the mechanisms, to get the friction coefficients of SG and SME. For the identification of a single degree-of-freedom machine with periodic operating speed, a methodology is adopted in this study. The equation of motion is transferred to a set of linear equations with the Fourier coefficients of the kinetic energy, potential energy, and dissipation function of the system as the unknown variables. With the specified driving velocity and torque, the equation set can be solved to get the coefficients, and then the inverse Fourier transform can be applied to get the system parameters. A slider-crank mechanism is used as the example to investigate the accuracy of the methodology. It is found that the root-mean-square errors of the parameters are less than 0.07%. Experimental instruments are used to measure the input velocities and torques of the mechanisms with or without lubricant in different operating speeds. The measured results are used to identify the system parameters of the mechanisms. Then the friction coefficients between SG and SME can be analyzed based on the dissipation functions. According to the results of this study, the dissipation function of the SCM with lubricant is about 5% less than that without lubricant; the function is increased about 3.7% due to SME. The averages of the friction coefficients between SG and SME are 0.156506 and 0.084066, respectively. The results of this study are believed to be valuable for designing and analyzing SCM and VLSM.
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Chen, Sheng-Chih, and 陳聖智. "Coupling Analysis of Vibration and Fatigue Crack Growth for the Cracked and Flexible Connecting Rod in a Crank-Slider Mechanism." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/544dbg.
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碩士中原大學
機械工程研究所
92
ABSTRACT Considering a crank-slider mechanism, analysis the transverse vibration of the cracked flexible connecting rod is analyzed in this study. First of all, the connecting rod is assumed as the Euler’s beam, then the equations of motion and boundary conditions are derived by Hamilton’s principle, that the moving boundary conditions are the same with the real situation, which connecting rod at one end of slider. Moreover, using the Galerkin method with mode shape function that satisfies the boundary conditions, the equations of motion are reduced to the Mathieu equations. And then, the Runge-Kutta method is determine to the transient amplitude of continues and breathing models. Just consider the coupling analysis of the vibration and the fatigue crack growth. The results reveal that the natural frequency of connecting rod is not influenced by the angular of the velocity. When the ratio of crack depth increases, the transverse amplitude increases a little. Since the coupling analysis of vibration and fatigue crank growth for the cracked and flexible connecting rod in a crank-slider mechanism is lacking in the literature. Thus, providing a procedure of coupling analysis is the major accomplishment.
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Yeh, Chin-Kun, and 葉晉坤. "Coupling Analysis of Vibration and Fatigue Crack Growth for the Flexible Connecting Rod with the Breathing Crack in a Crank-Slider Mechanism." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/p38thk.
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碩士中原大學
機械工程研究所
92
Based on Timoshenko theories, the vibration and fatigue analyses are combined to discuss the vibration behavior of a cracked rod of crank-slider mechanism with the crack growth in this study. The natural frequency is changed when the crack is growing. Therefore the amplitude of vibration is affected by the loading frequency. The model of breathing crack is applied to simulate the opening and closure crack, which affects the behavior of vibration. The analysis of vibration and fatigue for a cracked rod are coupled in this study. The interaction between vibration and fatigue are determined and discussed. At first, the connecting rod is assumed as Timoshenko’s beam, then the equations of motion and boundary conditions are derived by Hamilton’s principle, that the moving boundary conditions of connecting rod at one end of slider are considered. Moreover, using the Galerkin method with mode shape function that satisfies the boundary conditions, the equations of motion are reduced to Mathieu equations. And then, Runge-Kutta method is used to determine the transient amplitude for breathing crack model. The modified Forman equation is used to determine the rate of fatigue crack growth, and the crack depth is corrected cycle by cycle. When the crack depth ratio increases, the amplitude increases.
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Hsiung, Hsin-Yi, and 熊欣怡. "On the Variable Speed Servo-Slider-Crank-Mechanisms with Two Inputs." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/09177737225898347258.
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碩士國立成功大學
機械工程學系
89
This works targets on a four-bar slider-crank mechanism. The input of this mechanism is the output of a differential mechanism with two degrees of freedom. And, its inputs are a constant speed motor and a variable speed servomotor. The purposes are to avoid the dimensions of the mechanism must change when the required output motion is different for the designs with constant speed motors, and to avoid the use servomotors with big power. The approach can reduce the size of the servomotor power requirements by optimal the speed of constant speed motor. This work designs five types slider-output motion, and compare the dynamic of the design with only one servomotor driving and the design with the combination of a constant motor and a servomotor. The results show that the constant motor provides the most power, and the servomotor controls the variation of the speed. This proves that the proposed design is feasible.
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Yang, Jing-Chin, and 楊景欽. "Application of Elliptical Gears on the Dynamic Balance of Crank-Slider Mechanisms." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/74784284054457854516.
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碩士國立臺北科技大學
機電整合研究所
90
This study is to investigate the application of elliptical gears on the dynamic balance of crank-slider mechanisms where a pair of the first-order or second-order elliptical gears rotates with the crankshaft so that the shaking force and shaking moment of the mechanism can be reduced. The arrangement of elliptical gears can make the crank rotated with constant speed or variable speed. This study also investigates the effect of the factors, such as the phase shift, eccentricity, and mass of the elliptical gears, on the dynamic balance of the mechanism. In addition, the pitch curve of the first-order elliptical gears is optimized by setting the half major axis and eccentricity of the elliptical gears as design variables and using the minimization of the root-mean-square value of shaking force and/or shaking moment as an objective function. From the study, the following results can be concluded: No matter constant speed or variable speed rotation of the crank, the use of the elliptical gears can effectively decrease the shaking force and shaking moment, especially by using the first-order elliptical gears and constant speed rotation of the crank. The phase shift being equal to 180 degree can get better dynamic balance of the mechanism. When changing the eccentricity or mass of the elliptical gear, a critical value is found. Lower than this value, the dynamic balance can be improved by increasing the eccentricity or mass. Greater than this value, the dynamic balance is deteriorated. Finally, the optimization process can effectively decrease the root-mean-square value and maximum value of the shaking force and shaking moment of the crank-slider mechanism.
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Huang, Chai-Long, and 黃再隆. "Dynamic Analysis of Flexible Slider-Crank Mechanisms with Nonlinear Finite Element Method." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/36902307474478377468.
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碩士國立臺灣大學
機械工程學研究所
88
Previous researches in finite element formulation of flexible mechanisms usually neglected high order terms in the strain energy function. In this thesis we examine closely the effect of this approach in predicting the dynamic response of a flexible slider-crank mechanism. The effects of neglecting shear deformation and adopting the simplified slider-motion constraint on the accuracy of the numerical simulations are also discussed. By retaining all high order terms in the strain energy function, including the usually-neglected quartic term of the displacement gradient, the equations of motion naturally become nonlinear, which can be conveniently solved by Newmark method. In the low-speed range it is found that the dynamic responses predicted by nonlinear and linear approaches make no significant difference. When the rotation speed increases up to about one fifth of the fundamental bending natural frequency of the connecting rod, on the other hand, simplified approaches begin to incur noticeable error. This error is more significant for links with small slenderness ratio. Specifically, for a connecting rod with slenderness ratio 0.01 the conventional simplified approaches overestimate the vibration amplitude almost by 10 folds when the rotation speed is comparable to the fundamental natural frequency of the connecting rod. Generally speaking, the effect of shear deformation should be taken into account for a connecting rod with large slenderness ratio. Furthermore, the error induced by adopting simplified slider-motion constraint grows as the crank length and slider mass increase. These effects are enhanced as the mechanism operates at a speed comparable to the fundamental bending natural frequency of the connecting rod.
27
Chen, Wei-Ren, and 陳維仁. "A Study of Variable-Speed Servo-Linkage-Mechanisms with Crank-Input and Slider-Output." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/35820349754258817689.
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博士國立成功大學
機械工程學系
87
In general, when the power input of a linkage-mechanism is a rotary motor, this motor is traditionally designed for running at a constant speed. This research, from the kinematic point of view, proposes an alternate approach of varying the crank’s speed of the mechanism to meet various desired output motions without modifying the geometric dimensions of the original mechanism. At first, the kinematic relations between the input link and the output link of 4-bar and 6-bar linkage-mechanisms are derived. Then an approach is proposed for deriving useful input speed trajectories for any type of linkage-mechanisms with a crank-input and a slider-output. To show the feasibility of this variable-input-speed method, control algorithm regarding how this servo system works is also presented. To further demonstrate the procedure of this work and show its practicability, four examples, including 4-bar slider-crank mechanisms, 6-bar Watt-type mechanisms, 6-bar Stephenson-type mechanisms, and 6-bar Knuckle-Joint-type mechanisms, are discussed. These examples include cases of purely speed trajectory design and the combined design of speed trajectory with linkage dimensions. Finally, a prototype of this “Servo-Linkage-Mechanism” is built and tested. And, results of experiments from the prototype verify the feasibility of this work.
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Teng, Wei-wen, and 鄧緯文. "PC based Pseudo Model Following Discrete Integral Variable Structure Control of Positions in Slider Crank Mechanisms." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/05831035626579659096.
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碩士義守大學
電機工程學系碩士班
97
This paper proposes a pseudo model following (PMF) discrete integral variable structure control (DIVSC) scheme to control the position of a slider crank coupled with a PM synchronous motor. Applying the Grey modeling method, the reference model and plant are on-line converted to pseudo reference model and accumulated model respectively. The advantage is that the least data and memory are used in this modeling procedure. The DIVSC is introduced to guide the model following motion. The integral controller is used to reduce the steady state error. The switching controller is used to finish the sliding motion. The two existing condition of the discrete sliding mode are introduced in this paper, too. Finally, the position control of the slider crank is used to show the performance of the proposed control scheme. The simulation and experimental results show the robustness and the practicability.