International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 07 Issue: 07 | July 2020 www.irjet.net p-ISSN: 2395-0072 © 2020, IRJET | Impact Factor value: 7.529 | ISO 9001:2008 Certified Journal | Page 1388 Cam Design using Polydyne Approach Mayur Ade 1 , Natasha Kucheriya 2 , Shrijeet Laware 3 , Thoravi Patil 4 , Mr. Ashish Jain 5 , Mr. M.Y. Dakhole 6 1-4 Final Year (B.E.) Students 5 Manager in P.T.E at A.R.A.I, Pune 6 Assistant Professor at P.E.S. Modern College of Engineering 1-5 Department of Mechanical Engineering, P.E.S MCOE, Pune ---------------------------------------------------------------------***---------------------------------------------------------------------- Abstract – The valve train often faces a challenge with noise and vibration due to the variation which exists in the actual cam profile and the calculated cam profile. In conventional approaches, the design of cam includes only valve lift curve and excludes stiffness as well as the elasticity in the linkages which causes discrepancy in the cam command and follower response. Therefore, Polydyne Cam approach can be used which accounts for the elasticity and stiffness in the design process and in turn reduces this discrepancy. Key Words: Valvetrain, Cam, Follower, Polydyne 1. INTRODUCTION The Valve train is an essential mechanical system that controls the operation of intake and exhaust valves in an internal combustion engine. The stiffness of valve train has significant impact on the operation of the engine. The analysis of the valve trains mainly relies on valve acceleration data, because it provides information on the dynamic characteristics. Cam and follower are an integral mechanism in the valve train. Cams are used to convert the rotary motion to linear motion. As cam rotates, the follower rises and falls in a process known as reciprocating motion. Despite its advantages, cams have severe limitations namely that they cannot transmit large forces and significant additional acceleration forces are generated when the cam is operated at high speed. The inherent flexibility of a cam device may induce unwanted vibration of the follower, which will reduce positional accuracy and cause increased forces, noise and operating cost. Because the property of cam profile directly affects the performance of the cam mechanism, numerous cam profiles have been proposed to reduce vibration of cam follower system. However, in many cases, cams are subjected to high operating speed, which makes the matter of vibration reduction tougher. In such situations, the factors of elasticity and backlash must be taken into consideration if vibration and impact loads are to be avoided and minimized. This can be achieved by using Polydyne cam design method. 1.1 Literature Review Preben W. Jensen [1] in his book proposes clear introduction to those problem-solving methods used in the design, application, and manufacture of cams based for the most part on exhaustive studies of the English and German literature on the subject, the book unifies this scattered information in the single practical treatment, concentrating on both the graphical and analytical methods needed to design and produce cams and cam systems. It also focuses on the synthesis and analysis of polynomial equations for follower motion in the foregoing literature. A comparative study between 3-4-5, 4-5-6-7 and 5-6-7-8-9 polynomial curves has been depicted. Harold A. Rothbart [2] discusses the basics of cam profile the theoretical and practical design considerations for high-speed cam-follower performance. He has also said that the maximum acceleration values of the cam should be as small as possible to give small inertia loads. Stoddart David A. [3] based on polynomial equations offers a versatile and comprehensive approach encompassing the dynamic aspects of machine operations while designing cams using Polydyne Cam method. The effects of dynamic factors on cam design and operation are evaluated and specific example to demonstrate practical application of polydyne approach is demonstrated. Tushar Kiran [4] has presented analyses of 2-3 polynomial cam profile, 3-4-5 polynomial cam profile and 4-5-6-7 polynomial cam profile are presented. Kinematic and dynamic analyses are carried out using motion equations. The kinematic analysis presents follower characteristics of displacement, velocity and acceleration. Dynamic analysis presents pressure angle, spring force, inertial force and resultant force. Combined plots enlisting the follower characteristics of displacement, velocity and acceleration are presented for above mentioned polynomial cam profiles. A. S. More [5] has discussed valve train analysis procedures that are carried out in two stages kinematic and dynamic analysis. Kinematic analysis is used for design of a valve lift profile and find out static forces and Oil film characteristics, etc. Dynamic analysis is used to determine the dynamic movement of valve train component considering the effect of inertia and stiffness. Dong-Joon Chun [6] discussed the mass property data associated with the tuning of the valve train that can be