MODELLING AND ANALYSIS OF CAM SHAFT

Transcription

1 MODELLING AND ANALYSIS OF CAM SHAFT 1 K.NAGA MANENDHAR RAO 2 DR.THRISEKHAR REDDY 3 SRIHARI MALLELA 1pg Scholar, Department of Mechanical Engineering,nalanda institute of engineering and technology, satenapalli, Guntur, Andhra Pradesh Professor of Mechanical Engineering, nalanda institute of engineering and technology, satenapalli, Guntur, Andhra Pradesh pg Scholar, Department of Mechanical Engineering, nalanda institute of engineering and technology, satenapalli, Guntur, Andhra Pradesh ABSTRACT A cam is a mechanical device used to transmit motion to a follower by direct contact. The driver is called A camshaft is a shaft to which a cam is the cam and the driven member is called the follower. fastened or of which a cam forms an integral part. In In a cam follower pair, the cam normally rotates internal combustion engines with pistons, while the follower may translate or oscillate. the camshaft is used to operate poppet valves. It then consists of a cylindrical rod running the length of the cylinder bank with a number of oblong lobes protruding from it, one for each valve. the rotation of the camshaft and the rotation of the crankshaft is of critical importance. Since the valves control the flow of the air/fuel mixture intake and exhaust gases, they must be opened and closed at the appropriate time during the stroke of the piston. Figure1:Cam and Cam Shaft. This camshaft is rotate at high speeds causing vibrations in the system. Camshafts are also subjected to varying contact fatigue loads due to the contact of the plunger on the cam. Camshafts are rotating components with critical load; these exact values are needed to be determining to avoid failure in camshaft. Here in this project modeling of camshaft is done in solid works 2016 design software and static analysis and dynamic analysis is carried out in ansys 14.5 work bench by using different material on given load condition. 1. INTRODUCTION Figure 2: Cam Shaft. The camshaft is driven by the engine's crankshaft through a series of gears called idler gears and timing gears.the gears allow the rotation of the camshaft to

2 correspond or be in time with, the rotation of the crankshaft and thereby allows the valve opening, valve closing, and injection of fuel to be timed to occur at precise intervals in the piston's travel. To increase the flexibility in timing the valve opening, valve closing, and injection of fuel, and to increase power or to reduce cost, an engine may have one or more camshafts. Typically, in a medium to large V-type engine, each bank will have one or more camshafts per head. In the larger engines, the intake valves, exhaust valves, and fuel injectors may share a common camshaft or have independent camshafts. Depending on the type and make of the engine, the location of the camshaft or shafts varies. The camshaft(s) in an in-line engine is usually found either in the head of the engine or in the top of the block running down one side of the cylinder bank. When the piston travels below the level of the ports, the ports are "opened" and fresh air or exhaust gasses are able to enter or leave, depending on the type of port. The ports are then "closed" when the piston travels back above the level of the ports. Valves are mechanically opened and closed to admit or exhaust the gasses as needed. The valves are located in the head casting of the engine. The point at which the valve seats against the head is called the valve seat. Most medium-sized diesel engines have either intake valves or exhaust valves or both intake and exhaust valves. Figure 3: Rotation of Cam Shaft Cam is a mechanical member for transmitting a desired motion to a follower by direct contact. The driver is called cam and driven is called follower. Cam mechanism is a case of a higher pair with line contact. Camshaft is the Brain of the engine must include cam lobes, bearing journals, and a thrust face to prevent fore and after motion of the camshaft. In addition camshaft can include a gear to drive the distributor and an eccentric to drive a fuel pump. Camshaft is controlling the valve train operation. Camshaft is along with the crankshaft it determines firing order. Camshaft is along with the suction and exhaust systems it determines the useful rpm range of the engine. Camshaft is used in the engine for transfers motion to inlet & exhaust valve. If transfer of motion is not proper then the stokes will not work in proper way. Also it effects on performance of engine. To make work of camshaft in precise way. It is required in order to design a good mechanism linkage, the dynamic behaviour of the components must be considered; This includes the gross kinematic motion and self-induced vibration motion. Dynamic models were created to obtain insight into dynamic behaviour of the system prior to manufacturing. These models were mathematical tools used to simulate and predict the behaviour of physical systems. They contain systems properties

3 which are masses, stiffness constants, and damping coefficients. The automotive sector has reached a very high production capacity in the last decades. Depending on this increasing capacity, its stable growth is anticipated in the world economy. The economic value of the work capacity in the automotive sector is very large and this shows that the automotive sector is the 6th economic sector worldwide. The sector has an interrelationship with more than 300 different fields. So, if there is any malfunction in the main or side industries, the whole functions of the produced cars are influenced. On the other hand, the failure analysis is a special field of study for materials and mechanical engineers. On one side, the materials engineer is intended to develop his/her observational and reasoning skills for the understanding of interrelationship between observable features and properties or performance. On the other side, the mechanical engineer studies on the possible failure locations and types and amount of the existent stress levels. Many studies have been carried out on the automotive failure analysis is that the mostly failed parts are from engine and its components among the automotive failures. This is followed by the drive train failures. Among the studies on the engine component failures, the prediction of fatigue failure in a camshaft using the crack-modeling method. 2. LITERATURE SURVEY [A.S.Dhavale], [V.R.Muttagi] studied Modelling and Fracture Analysis of camshaft to design good mechanism linkages the dynamic behaviour of the components must be considered, this includes the mathematical behaviour of physical model.. In this case, introduction of two mass, single degree of freedom and multiple degree of freedom dynamic models of cam follower systems are studied. The failure is occurred as sudden fracture at very close to journal location, where there is a stress concentration. The main reason of the fracture is determined as a casting defect and the camshaft of Vehicles manufactured from that particular series of camshaft should be replaced. Also, non-destructive testing procedures of the component supplier should also be improved as the defect can easily be detectable by standard non-destructive techniques. [R.Mahesh],[Mali1],[D.Prabhakar] presented Design Optimization of Cam & Follower Mechanism of an Internal Combustion Engine for Improving the Engine Efficiency. 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. This indicates change of the flat face of roller follower to a curved face roller follower mechanism results in low frictional losses due point contact which results in improved in mechanical efficiency of internal combustion engine by 65% to 70%. 1s.g.thorat, 2nitesh dubey, 3arvind shinde, 4pushkar fulpagare,5manish suryavanshi 1Department of Mechanical Engineering, Mitcoe, Pune2,3,4,5Mit College of Engineering, Pune The goal of the project is to design cam shaft analytically, its modelling and analysis under FEM. In FEM, 3heavier of cam shaft is obtained by heavier the collective 3heavier of the elements to make the cam shaft robust at all possible load cases. This analysis is an important step for fixing an optimum size of a

4 camshaft and knowing the dynamic behaviours of the camshaft. Initially the model is created by the basic needs of an engine with the available background data such as power to be transmitted, forces acting over the camshaft by means of valve train while running at maximum speed. M. Shobha Assistant Professor Department of Mechanical Engineering IndoAmerican Institutions Technical Campus, Anakapalle, AP,India. Analysis of Cam Shaft in Automobiles Using Different Materials. In this project, a cam shaft will be designed for a 150cc engine and modelled through pro/engineer. Present used material for camshaft is cast iron. In this work, the camshaft material will be replaced with steel and aluminium alloy. Structural analysis and model analysis will be done on cam shaft using cast iron, steel and aluminium alloy. Comparison will be done for the three materials to verify the better material for camshaft. Modelling will be done using pro/engineer software and analysis will be done using ANSYS. Zeyaullah Ansari1, Mohd Anwar2, Md Yousuf Ahmed31,2,3 Asst. Professor in Mechanical Department, Lords Institute of Engineering & Technology, Hyderabad. Finite Element Structural Analysis of Automobile Camshaft. In the present work composed Automobile camshaft bynumerical Calculations there after it is planned by utilizing Modelling software PRO-E and CAE Analysis is done in ANSYS by differing material AL Metal Matrix Composite (ALMMC) to research the deformation, stress and strain developed on camshaft. The examination will give the most ideal approach to think us for the further future work of camshaft. Keywords: Design, Analysis, Pro-E, Ansys, IC Engines. 3.PROBLEM STATEMENT 3.0 Problem identification Crank shaft of Power loom system in textile machinery is a critical component which transmits the power from motor to machinery at a required speed and controls the complete operation. If crank shaft of the system fails then entire process will stop hence it is important to design the power loom system for continues operation. There is need from industry Dhayafule Textiles for the vibration analysis of the crank shaft of a power loom. 3.1 Objectives of Project This work comprises the following objectives for safe design of existing power loom system. To Select a critical component i.e. crank shaft of power loom system. To Model the existing crank shaft of power loom system then numerical analysis will be carried out in FEA To carry out Experimentation using FFT analyzer. To Compare the experimental and numerical results. To modify the component for optimization by changing the geometry then the analysis will be carried out. 4. DESIGNING OF ACAM SHAFTBY USING SOLID WORKS 4.1 Introduction To Solid works : Solid works mechanical design automation software is a feature-based, parametric solid modelling design tool which advantage of the easy to learn windows TM graphical user interface. We can create fully associate 3-D solid models with or without while utilizing automatic or user defined relations to capture design intent. Parameters refer to constraints whose values determine the shape or geometry of the model or assembly. Parameters can be either numeric

5 parameters, such as line lengths or circle diameters, or geometric parameters, such as tangent, parallel, concentric, horizontal or vertical, etc. Numeric parameters can be associated with each other through the use of relations, which allow them to capture design intent A Solid Works model consists of parts, assemblies, and drawings. Typically, we begin with a sketch, create a base feature, and then add more features to the model. (One can also begin with an imported surface or solid geometry). We are free to refine our design by adding, changing, or reordering features Design procedure of Cam Shaft For designing the Connecting Rod the following procedure has to be follow Sketchand Extrude Sketch and Extrude 2d sketch of a cam shaft Cam Shaft Figure Sketch &revolve Different Views of Cam Shaft

6 5. ANALYSIS DEFINATION &STEPS: The steps needed to perform an analysis depend on the study type. You complete a study by performing the following steps: Create a study defining its analysis type and options. If needed, define parameters of your study. A parameter can be a model dimension, material property, force value, or any other input. Define material properties. Specify restraints and loads. The program automatically creates a mixed mesh when different geometries (solid, shell, structural members etc.) exist in the model. Define component contact and contact sets. Mesh the model to divide the model into many small pieces called elements. Fatigue and optimization studies use the meshes in referenced studies. Run the study. View results. 5.1 Analysis on Cam Shaft by using ansys 14.5 work bench software The analysis of connecting rod models are carried out using ANSYS software usingfiniteelement Method. Firstly the model files prepare in the SOLIDWORKS SOFTWARE. Then are exported to ANSYS software as an IGES files as shown in figure Figure5.1 structural analysis 5.2 Materials and their properties 5.3 Load & fixed support Fixed support

7 Load Load at 750N Total Deformation 5.3 Meshing Meshing is probably the most important part in any of the computer simulations, because it can show drastic changes in results you get. Meshing means you create a mesh of some grid-points called 'nodes. It's done with a variety of tools & options available in the software. The results are calculated bysolving the relevant governing equations numerically at each of the nodes of themesh. The governing equations are almost always partial differential equations, and Finite element method is used to find solutions to such equations. The pattern and relative positioning of the nodes also affect the solution, the computational efficiency & time. Maximum Strain 6.2 Material: Aluminium Alloy Maximum Stress Mesh Type: Tetrahedral No. of nodes: No. of elements: STRUCTRUALANALYSISRESULTS 6.1 Material: 42CrMo4 Maximum Stress Total Deformation

8 Maximum Strain 6.4 Material: Magnesium Alloy Maximum Stress 6.3 Material: Aluminium Silicon Magnesium Alloy Maximum Stress Total Deformation Total Deformation Maximum Strain Maximum Strain 7. MODAL ANALYSIS RESULTS 7.1 Material: 42CrMo4 Mode 1

9 Mode 2 7.3Material: Aluminium Silicon Magnesium Alloy Mode 1 Mode 3 Mode 2 7.2Material: Aluminium Alloy Mode 1 Mode 3 Mode Material: Magnesium Alloy Mode 1 Mode 3 Mode 2

10 Mode 3 RESULT TABLE For comparisons of the results obtained From the static analysis result tables it is concluded that 42CrMo4 show least stress and least deformation & strain value on same static load condition. From the Modal analysis result tables it is concluded that 42CrMo4 shows Less deformation results for given frequency. Hence for both Structural and Modal Analysis 42CrMo4 (Special Alloy Steel) it is best suitable material for connecting rod. CONCLUSION Modelling and analysis of cam shaft is done. Modelling of cam shaft is done in solid works 2016 design software. Static analysis is carried out in Ansys work bench Load applied is 750N and materials applied are 42CrMo4 (special alloy steel ),Aluminium Silicon Magnesium Alloy, Aluminium Alloy, and Magnesium Alloy. Structural deformations such as stress, deformation and strain are studied and

11 tabulated. From the results we can conclude that 42CrMo4 (special alloy steel) is showing low stress and deformation values compared to remaining materials. Dynamic analysis (model) is carried out on three different mode conditions. Deformation values on different modes with respective different frequencies are noted as result and tabulated. REFERENCES ColinR.Ferguson(1986), InternalCombustion EngineAppliedThermosciences JohnB. Heywood(1988), InternalCombustionEngine Fundamentals RichardStone(1999), Introduction tointernalcombustionengines (3 rd edi tion) CharlesFayetteTaylor(1985), TheInter nalcombustionengineinthetheoryand Practice,Volume1 CombustionEngineintheTheoryand Practice,Volume2 J.H.Weaving(1990), InternalCombustionEng ineering DimitrovL.(2001), Principleof MechanicalEngineeringDesign RowlandS.Benson(1979), InternalCombustion Engines,Volume2 CharlesFayetteTaylor(1985), TheInternal- Ricardo(1933), TheHigh- SpeedInternalCombustion Engine Lanchester(1914), EngineBalancing Root (1932), Dynamics ofengineandshaft McVey(1955), Materials inenginedesign SAE(1957)SP-8 Crankshaft androds, bearings, pistonsandpistonrings AUTHORS 1. k.naga Manendhar rao Department of Mechanical Engineering, College Name : Nalanda Institute of engineering & Technology, Mandal: sattenpalli, Dist: guntur A.P, India,Pin: id: manendhar.555@gmail.com 2.Dr.Thrisekhar Reddy Professor of Mechanical Engineering, College Name :Nalanda Institute of engineering & Technology, Mandal: sattenpalli, Dist: guntur A.P, India,Pin: id:sekhar02351@gmail.com 3. Srihari Mallela Department of Mechanical Engineering, College Name : Nalanda Institute of engineering & Technology Mandal: sattenpalli, Dist: guntur A.P, India,Pin: id: sriharimallela327@gmail.com