International Journal of Innovative Technology and Exploring Engineering (IJITEE) ISSN: 2278-3075, Volume-9 Issue-6, April 2020 759 Published By: Blue Eyes Intelligence Engineering & Sciences Publication Retrieval Number: F3897049620/2020©BEIESP DOI: 10.35940/ijitee.F3897.049620 Abstract: This research paper tends to have an insight into the dynamics of cam and tappet of diesel engine which is supposed to work continuously for a longer period under huge variable loads to operate the valves of an internal combustion engine. The dynamics of valve gear train is so elemental in the due functioning of an engine. In this research, the analysis of five-order polynomial cam has been done to find the profile of displacement, velocity, acceleration and jerk for the suitability of diesel engines. The MATLAB software has been used as the vital aid in this analysis. This insight would sure be helpful in improving the mechanism of cam profile generation leading to betterment of camshaft design so as to increase the overall efficiency of the engine. Keywords: Camshaft, Cam dynamics, Polynomial cam, Polydyne cam, Valve gear train. I. INTRODUCTION The current research is focused on studying the kinematics of diesel engines so that it can facilitate the actuation of valves in the due course of a complete engine cycle. The key parameters in this research are contacting external forces and the kinematic quantities [1]. By simulating the dynamics of valve gear train system, the key parameters can be deduced. The whole of the research work has been done on valve operating system having push-rod and flat faced tappet which are frequently equipped in diesel engines. A cam is a device for conversion of one type of motion [2],[4],[7] into another as desired to have specific output from the system. Generally, the rotary motion of the cam is transformed into follower oscillation, translation, or both. Cams are generally manufactured [2],[6] from robust and hard material including medium to high carbon steels which are treated of case hardening and hardened ductile or grey cast iron to minimize wear[5]. For minor loads and speeds, the cams of marine engines are produced of brass or bronze. Such systems are often [9] utilized in all categories of machines. Revised Manuscript Received on April 1, 2020. * Correspondence Author Rajendra Singh Rajput*, Department of Mechanical Engineering, ITM University Gwalior-474001, Mail ID: rs.rajput@ itmuniversity.ac.in Anshul Gangele, Department of Mechanical Engineering, Sandip University, Nashik (India)-422213 Mail ID: anshulgangele@gmail.com Arun Singh Kushwah, Department of Mechanical Engineering, ITM University Gwalior-474001, Mail ID: arunkushwah@itmuniversity.ac.in Fig.1. Components of valve train system, source [10] The fig.1 lucidly describes the application of four bar linkage mechanism in the context of an I C engine. The understanding of dynamics of this system eases off the calculation related to transmission of torque to camshaft. The location of a concerned link’s centre of rotation (instantaneous) is used to deduce cam torque [9]. Research on analysis of kinematics of types of constant-breadth cam-follower mechanisms had also been done [8]. This analysis covers the study of equations for the lift, velocity and the acceleration profile of the tappet, powered by cam, having constant width profile with uniform angular velocity. In this study also follower is flat-faced type. In another work [3] stated that while analyzing the dynamics of such intricate systems, the forces subjected to cam, the spring forces and tangential forces are expected to be calculated. Most of the time speed is higher or member is elastic one, hence noise, chatter and unusual wear are studied [5]. Research had also been done to increase the efficiency of engine considering tribology of engine [11] and kinematic and wear pattern of valve gear train [12]. The profile of cam is having a great roll in the further dynamic analysis of cam follower systems. Subsequently, it has direct effect on the wear [14] and lubrication mechanism [13] of cam-follower systems. The analysis of Elasto hydrodynamic lubrication has vital part in such systems operating at high hertz pressures. This work tends to improve the cam profile using the polydyne 5- order cam profile through the evaluation of all the kinematic parameters which is a better choice over cycloidal cam profile. Kinematic Analysis of Polydyne Cam Profile of A Diesel Engine Rajendra Singh Rajput, Anshul Gangele, Arun Singh Kushwah