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Design Optimization of Cam & Follower Mechanism of an Internal Combustion Engine for Improving the Engine Efficiency  [PDF]
Mahesh R. Mali, Prabhakar D. Maskar, Shravan H. Gawande, Jay S. Bagi
Modern Mechanical Engineering (MME) , 2012, DOI: 10.4236/mme.2012.23014
Abstract: The current cam and follower mechanism in four stroke internal combustion engine employs a flat follower. In this work an attempt is made to change the flat face of follower to a curved face follower, so that the required point contact can be achieved. As line contact between existing cam and follower mechanism results in high frictional losses which results in low mechanical efficiency. It is observed that the frequency of vibration in the existing and modified cam and follower mechanism remains almost same. The finite element approach is used to perform the analysis.
Impact of the cam and follower cooperation and of lubrication on the cam wear  [PDF]
P. Fol?ga,R. Burdzik,?. Konieczny,Z. Stanik
Archives of Materials Science and Engineering , 2012,
Abstract: Purpose: The paper provides an analysis of the reasons for excessive wear of the cam/follower system components based on physical and mathematical models developed to describe the impact of selected material, technological and operational factors. Owing to the comparison between the calculation results obtained and the actual cam wear values, it was possible to asses the correctness of the wear models taken into consideration.Design/methodology/approach: The research in question included preparation of a mathematical cam wear model developed by way of dimensional analysis as well as finite element (FEM) based structural models for a cam/follower system. The aforementioned FEM models were noted in a parametrical form using macro commands of the COSMOS/M system, and hence it was possible to analyse contact problems in various cam positions and change the selected analytical parameters (e.g. dimensions, material parameters).Findings: The main reasons for excessive cam wear include inferior quality of the cam and follower frictional couple lubrication as well as edge-type cooperation between the cam and the cam follower. At the same time, a significant impact on the wear is exerted by hardness of the cam and its follower.Research limitations/implications: Wear of cams and cam followers operating in timing gear systems of vehicle combustion engines takes place as an effect of friction occurring in presence of lubricant. During standard operation, components of the cam/follower system may be subject to an excessive or accelerated wear process. This study is an attempt to establish the reasons for this phenomenon to occur in order to control such cases.Originality/value: In order to counteract the phenomenon of accelerated wear of cams, one should consider increasing the required hardness of their working surfaces.
Influence of Temperature on Cam-tappet Lubrication in an Internal Combustion Engine
温度对内燃机排气凸轮/挺柱润滑的影响研究

CHANG Qiu-ying,YANG Pei-ran,CHEN Quan-shi,WANG Jing,
常秋英
,杨沛然,陈全世,王静

摩擦学学报 , 2006,
Abstract: Transient thermoelastohydrodynamic lubrication (TEHL) simulation and isothermal elastohydrodynamic lubrication(EHL) simulation were performed on the exhausting cam-tappet friction pair of an internal combustion engine.Results show that the center pressure,the thickness of the lubricant film and the friction coefficient,all calculated from two models,exhibit similar variation trend during a rotating cycle.The magnitude,however,presented significant difference.Results show that effect of temperature should not be neglected in researching the lubrication of cam-tappet pairs.
Cam-Gears Forces, Velocities, Powers and Efficiency  [PDF]
Cam-Gears Forces, Velocities, Powers and Efficiency
American Journal of Engineering and Applied Sciences , 2017, DOI: 10.3844/ajeassp.2017.491.505
Abstract: The paper presents a method of the original type in order to determine the effectiveness of a mechanism camshaft and adept. The originality of this method consists of eliminating the friction. In this research analyzes the four types of side camshaft: 1. Camshaft rotary switch and the motherboard translated adept; 2. The mechanism with the camshaft rotary switch and openness to be translated with roll; The 3. The camshaft rotary switch and the rocking chair adept with roll; The 4. The camshaft rotary switch and the rocking chair adept. For any mechanism with the camshaft and the follower is uses a different method to determine the most efficient design. We take into account the mechanism (the timing end) cam, which is the second of the mechanism in internal combustion engines. Optimization of this mechanism (timing end), can improve the functionality of the engine and may increase the comfort of the vehicle too.
Experimental Investigation on the Performance of a Compressed-Air Driven Piston Engine  [PDF]
Chih-Yung Huang,Cheng-Kang Hu,Chih-Jie Yu,Cheng-Kuo Sung
Energies , 2013, DOI: 10.3390/en6031731
Abstract: This study presents an experimental investigation of a piston engine driven by compressed air. The compressed air engine was a modified 100 cm 3 internal combustion engine obtained from a motorcycle manufacturer. The experiments in this study used a test bench to examine the power performance and pressure/temperature variations of the compressed air engine at pressures ranging from 5 to 9 bar (absolute pressure). The engine was modified from a 4-stroke to a 2-stroke engine using a cam system driven by a crankshaft and the intake and exhaust valves have a small lift due to this modification. The highest power output of 0.95 kW was obtained at 9 bar and 1320 rpm. The highest torque of 9.99 N·m occurred at the same pressure, but at 465 rpm. The pressure-volume (P-V) diagram shows that cylinder pressure gradually increases after the intake valve opens because of the limited lift movement of the intake valve. Similar situations occurred during the exhaust process, restricting the power output of the compressed air engine. The pressure and temperature variation of the air at engine inlet and outlet were recorded during the experiment. The outlet pressure increased from 1.5 bar at 500 rpm to 2.25 bar at 2000 rpm, showing the potential of recycling the compressed air energy by attaching additional cylinders (split-cycle engine). A temperature decrease (from room temperature to 17 °C) inside the cylinder was observed. It should be noted that pressures higher than that currently employed can result in lower temperatures and this can cause poor lubrication and sealing issues. The current design of a compressed air engine, which uses a conventional cam mechanism for intake and exhaust, has limited lift movement during operation, and has a restricted flow rate and power output. Fast valve actuation and a large lift are essential for improving the performance of the current compressed air engine. This study presents a power output examination with the pressure and temperature measurements of a piston-type compressed air engine to be installed in compact vehicles as the main or auxiliary power system.
Synthesis and analysis of coupler curves with combined planar cam follower mechanisms
US Chavan, SV Joshi
International Journal of Engineering, Science and Technology , 2010,
Abstract: Cam and follower mechanisms are widely used to convert a rotary input motion into a controlled reciprocating or oscillating motion as output in machines or robots. As this mechanism has an ability to provide unlimited variety of output motions. Many works are done on the synthesis of coupler curves or path generation using four bar mechanism. The present work investigates the alternative way of dealing with the path generation problems of industrial application by using cam mechanisms. Proposed a new mechanism which comprises four bar and cam follower mechanism, these mechanisms are combined together to obtain a single-input combined cam mechanism (CCM). Dimensional synthesis has been carried out by guiding the coupler point along predefined path (ellipse or straight line) of profile cutting machine. One of the objectives was to compare the path of coupler in four bar and CCM. Further, kinematic simulation of both mechanisms was performed to estimate the error and validate the proposed methodology. Results show that coupler point follows same path as ellipse or straight line profile in both mechanisms. Proposed CCM successfully applied to the complex path generation problems of profile cutting machine like square, circle and figure eight profiles. A method of kinematic analysis of proposed mechanism was also discussed. Finally, dynamic stability and separation of cam follower contact was simulated by using Matlab Simulink tool. Results show that proposed CCM was found stable from kinematic and dynamic point of view. International Journal of Engineering, Science and Technology, Vol. 2, No. 6, 2010, pp. 231-243
Corner-Impact Bifurcations: a novel class of discontinuity-induced bifurcations in Cam-Follower Systems  [PDF]
Gustavo Osorio,Mario di Bernardo,Stefania Santini
Physics , 2007,
Abstract: This paper is concerned with the analysis of a class of impacting systems of relevance in applications: cam-follower systems. We show that these systems, which can be modelled as discontinuously forced impact oscillators, can exhibit complex behaviour due to the detachment at high rotational speeds between the follower and the cam. We propose that the observed phenomena can be explained in terms of a novel type of discontinuity-induced bifurcation, termed as corner-impact. We present a complete analysis of this bifurcation in the case of non-autonomous impact oscillator and explain the transition to chaos observed in a representative cam-follower example. The theoretical findings are validated numerically.
Free Energy and Internal Combustion Engine Cycles  [PDF]
William D. Harris
Physics , 2012,
Abstract: The performance of one type (Carnot) of Internal Combustion Engine (ICE) cycle is analyzed within the framework of thermodynamic free energies. ICE performance is different from that of an External Combustion Engine (ECE) which is dictated by Carnot's rule.
Combustion Model and Control Parameter Optimization Methods for Single Cylinder Diesel Engine  [PDF]
Bambang Wahono,Harutoshi Ogai
Journal of Optimization , 2014, DOI: 10.1155/2014/135163
Abstract: This research presents a method to construct a combustion model and a method to optimize some control parameters of diesel engine in order to develop a model-based control system. The construction purpose of the model is to appropriately manage some control parameters to obtain the values of fuel consumption and emission as the engine output objectives. Stepwise method considering multicollinearity was applied to construct combustion model with the polynomial model. Using the experimental data of a single cylinder diesel engine, the model of power, BSFC, , and soot on multiple injection diesel engines was built. The proposed method succesfully developed the model that describes control parameters in relation to the engine outputs. Although many control devices can be mounted to diesel engine, optimization technique is required to utilize this method in finding optimal engine operating conditions efficiently beside the existing development of individual emission control methods. Particle swarm optimization (PSO) was used to calculate control parameters to optimize fuel consumption and emission based on the model. The proposed method is able to calculate control parameters efficiently to optimize evaluation item based on the model. Finally, the model which added PSO then was compiled in a microcontroller. 1. Introduction Currently, energy and environmental pollution have become hot topics. Public and private transportations system plays an important role in people’s life. Vehicle has become one of the most important factors in this system. In Jakarta, it is reported that 70% exhaust gas pollution is from vehicles [1]. Internal combustion engine is the main power of the vehicle. The global challenge in internal combustion engine is the reduction of exhaust gas such as soot, [2, 3], CO, HC, and particulate matter (PM) emissions from vehicles by improving fuel consumption without sacrificing the vehicle performance. On the other side, most internal combustion engine methods that reduce either or soot emissions cause an increase in the other emissions [4]. Recently, with the environmental restrictions and sustainable development, pollution standards have been more and more stringent. For example, in Japan, the standard of diesel engine emission regulation is very high. In 2003 the MOE finalized very stringent 2005 emission standards for both light and heavy vehicles although it remained relaxed through the 1990s. In 2005 heavy-duty emission standards , ) were the most stringent diesel emission regulations in the world. In 2009, this standards were more
THE ANALYSIS OF CAUSES OF LORRY PISTON COMBUSTION ENGINE DAMAGE
Mária ?tefániková,Roman Morav?ík,Karin Kocúrová
Materials Engineering , 2012,
Abstract: The article deals with analysis of causes of lorry piston combustion engine damage. For docummentation and analysis of causes was used macroscopical, microscopical and scanning electron microscopy. The analysis showed that the reason of fatal damage resides in production process of lorry combustion pistons which proved in implication of fatigue damage and subsequent burnout in two piston place.
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