EXPERIMENTAL ANALYSIS OF CAM ROLLER OF INTERNAL COMBUSTION ENGINE BY CHANGE IN AREA OF CONTA (original) (raw)
Related papers
EXPERIMENTAL ANALYSIS OF CAM ROLLER OF INTERNAL COMBUSTION ENGINE BY CHANGE IN AREA OF CONTACT
Most of the IC engines used in the market have roller cam and follower mechanisms, having a line contact between the cam and the roller follower. In a effort to improve the mechanical efficiency of the mechanism the company requires us to change the line contact to a point contact. Hence it is required to change the flat roller follower to a curved profile. The existing cam & follower mechanisms used in Internal Combustion engines have a line contact between them causing frictional losses. These frictional losses in present line contact are being considered on the higher side. These frictional losses affect the total efficiency of an Internal Combustion engine. The mechanical efficiency of cam & follower mechanism is to be increase by minimising the frictional losses.The roller of rocker arm of a Hero Honda passion bike is replaced by new one to check performance experimentally.
Modern Mechanical Engineering, 2012
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.
Lubrication and frictional analysis of cam–roller follower mechanisms
Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology
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 ...
Shape Optimization of Roller Follower Mechanism for Improving Mechanical Efficiency
Cam follower mechanism is an important part of automobile engine that operates the inlet and outlet valve. The follower is in contact with the cam lobe. In this paper, the design of a roller follower has been modified to reduce the contact area of the follower so as to reduce the friction and wear loss of the follower. This in turn helps to improve the mechanical efficiency. The modified shapes are modeled in Solid Works and they have been investigated for modal analysis and static structural analysis using ANSYS 14.5. Different materials are investigated for the modified design in ANSYS which include Stainless Steel, Structural Steel and Chromium Steel, and the results are compared to select the optimal design for the follower.
Friction dissipation in reciprocating internal combustion engines: camshaft bearings
IOP Conference Series: Materials Science and Engineering, 2021
The increasing environmental awareness of the last decades has led to a huge tightening of the restrictions on vehicle pollutant and carbon dioxide emissions. Friction dissipation plays a strategic role as its reduction necessarily leads to a decrease in CO2 emissions. Valve timing system is responsible for a significant part of the overall friction losses and provides a relatively wide margin of improvement. This system regulates intake and exhaust flows in the combustion chamber. The camshaft allows the motion transmission between the crankshaft and the valves. The main goal of this research is the friction dissipation modeling in camshaft bearings of reciprocating internal combustion engines. The proposed model is aimed to investigate possible optimization strategies and to evaluate, with an appropriate precision to the design phase, different constructive solutions of the camshaft from the point of view of friction losses. An empiric model for the evaluation of the Stribeck curv...
The issues of designing of construction features of the internal combustion cam engine
Combustion Engines, 2017
On the pages of the article described cam-piston mechanism developed as an alternative to piston crank mechanism. The main feature of this mechanism is that the piston is dwell in the TDC by the 30°CA and thus allows combustion of the fuel in constant volume. Authors presented the process of designing an analytical cam. The starting point for the calculation was the displacement of piston graph and the limits of acceleration and velocity values obtained. The results of strength calculations of the cam with regard to fatigue problems are also presented. Calculations were carried out in order to reduce the weight of the cam. For this purpose, the Finite Element Method was used.
Friction Analysis of a Two Stroke Engine
Proceedings of the European Automotive Congress EAEC-ESFA 2015, 2015
Internal combustion engines continue to be the vehicles main propulsion system. For all engines, low friction levels are extremely important for the overall efficiency. Components and subsystems where friction reduction can take place are: crankshaft main bearings, conrod bearings, cam shaft bearings, balancer shafts (if present), auxiliary drives (chains, alternator etc.), valve trains and pistons/pistons ring with liners. This paper describes how the bearings were calculated and assesses motor mechanism friction losses in the engine mechanism.
Lubrication Analyses of Cam and Flat-Faced Follower
Lubricants
The principal factors that affect the characteristics of contact problem between cam and follower vary enormously during the operating cycle of this mechanism. This includes radius of curvature, surface velocities and applied load. It has been found over the last decades that the mechanism operates under an extremely thin film of lubricant. Any practical improvement in the level of film thickness that separates the contacted surfaces represents an essential step towards a satisfactory design of the system. In this paper a detailed numerical study is presented for the cam and follower (flat-faced) lubrication including the effect of introducing an axial modification (parabolic shape) of the cam depth on the levels of film thickness and pressure distribution. This is achieved based on a point contact model for a cam and flat-faced follower system. The results reveal that the cam form of modification has considerable consequences on the level of predicted film thickness and pressure di...
IJERT-Analysis Of Radial Cam With Roller Follower
International Journal of Engineering Research and Technology (IJERT), 2013
https://www.ijert.org/analysis-of-radial-cam-with-roller-follower https://www.ijert.org/research/analysis-of-radial-cam-with-roller-follower-IJERTV2IS60170.pdf A cam is a rotating or a reciprocating element of a mechanism which imparts rotating, reciprocating or oscillating motion to another element called follower. Cam mechanisms are used in many modern machines, including weaving looms, precision measurement instruments, automatic machine tools, automobile engines, and so on. The geometry of the cam profile is based on the type of motion of the cam and the type of the follower. MATLAB is the tool to optimize the motion and geometry of the cam mechanism and to evaluate the kinematic performance. In this project a MATLAB code is written for designing of the cam profile for combination of motions, cycloidal, uniform velocity for radial cam with roller follower. MATLAB is used to get optimum values of displacement and velocity. A solid model of the cam is designed in Pro/ENGINEER Wildfire 4.0 and the Modal Analysis is done in ANSYS 13.0 Workbench to find out the natural frequencies at respective Mode shapes of the cam.
Evaluation of cam and roller surfaces by wear testing and functional characterization
2008
Friction and wear are constant problems encountered in camshaft development. Among a wide amount of factors, surface topography is an important feature to improve in this complex system. Four parts of different shapes can be differentiated on an injection cam profile. Therefore the machining of such component is quite particular. Considering the complex shape of an injection cam, this paper is divided in two studies: 1. Variations of surface topography around freshly produced cams in order to emphasize the particular profile of cams which leads to a complex machining. 2. Evolution of surfaces during run-in in order to discover the effects of wear process on a group of roughness parameters. The results show a variation of density of peaks along the freshly produced cam surface and highlight also the importance of roller type on the evolution of topography. Further results show that summits of the surface are rounded off during run-in. Concerning the future, results of the study are encouraging to investigate more deeply the tribological behaviour (contact mechanic, oil film thickness) of the surfaces.