Design and Analysis of an Efficient Power Transmission for Light Weight Automobiles Muhammad Idrees Department Of Mechanical Engineering Institute Of Space Technology Islamabad, Pakistan Idrees1000781@gmail.com Faraz Khan Department Of Mechanical Engineering Institute Of Space Technology Islamabad, Pakistan Faz.khan1701@hotmail.com Abstract—In modern automobiles, the deemed requirements include the driving comfort of the driver, environment friendly performance, highly efficient and highly durable transmission system which require great advancements and improvements in the exiting technology to meet the rapidly growing demands of the customers. The power transmission is a very critical component which affects the performance, fuel economy, and the payload of the automobile. The paper focuses on the manual two-stage constant synchro-mesh configuration transmission system. The objective is to improve the fuel efficiency, improve the synchronization mechanism, greater life, and greater pay load for the Light Weight Automobiles. Material modification of the gears, synchronizer units and the transmission casing are intro- duced. Gear ratio modification and an improved mechanism for assembly are designed. An improved synchronization mechanism to enhance gear shift quality and smooth torque characteristics which will be more efficient with maximum friction during the synchronization action is developed. The casing is designed so as to accommodate minimum space, and high strength to weight ratio. I. I NTRODUCTION Despite of the fact that a lot of improvements are made in the automobile industry in recent era, still further improve- ments are required in order to meet the growing demands of the customers and to satisfy their need. Transmission system impacts the fuel economy, power, and Torque and vehicle performance. Performance depends upon the gear contact and shift quality of the system. Despite of the fact that shift quality of the transmission system has improved considerably in recent era but further improvements should be made in order to satisfy the customer expectations. Better gear shift quality results in the superior control and the drivability. The weight of the transmission and its components con- tribute significantly to the automobile fuel consumption. Hence, material and design modifications need to be intro- duced in order to decrease the weight and the fuel consumption of the automobile. During gear shifting, there exists grinding of the gears and the synchronous teeth which creates noise. Hence, the synchronizer mechanism needs to be improved in order to obtain better efficiency, smoother shifting of gears and low wear and tear characteristics. This paper mainly focuses on the improvement in the various components of the transmission system which includes the modification of the material for gears and casing. Finite elements Analysis are performed in Ansys in order to select the best suitable material for different components. Synchronizer action is improved by increasing the area of the frictional cone of the blocker rings which results in the increase of friction and reduction in the synchronization time. Hence, this will increase the shift quality between the gears. II. LITERATURE REVIEW U.S. Gupta, M.M. Petra introduced the concept of the compact gear box with 7 forward gears and 2 reverse gears. A normal 7 speed MT requires 8 gear pairs to provide 7 forward and 1 reverse gear but they presents a novel 7 speed MT designed with just 6 gear pairs giving 7 forward and 2 reverse gears thereby saving both the material cost as well as meeting the space constraints. [1] Volkswagen introduced the concept of a two shaft output gearbox for 6 forward and one back gear. In a conventional gearbox, input shafts transfers drive force to an output shaft on which the various gears are positioned. The more gears there are lined in row on such a drive shaft, the longer it will be. For the so-called short gearbox, uses two output shafts - on which the gears are arranged - instead of one. This reduces the installation length considerably. For a gearbox with two output shafts, the overall ratio comprises two factors: Firstly, the ratio of the input shaft to the output shaft Secondly, the ratio between the output shaft and the differential. [2] The earliest automotive transmissions required from the driver the ability to shifting at the correct time [3], otherwise the driver faced a gear clashing or even a shift blocking. In order to improve the shiftabilty, in 1934 started to be produced the first automotive transmission with all forward gears synchronized by means of conical synchronizers [4]. Sachin Agarwal describes the optimization of transmission system for performance parameters such as fuel economy, strength of gear, life and the shift quality. Mathematical model was developed for these parameters and target are set for the shifting time and required effort. Parameters are optimized wherever required. Benchmarking at every phase of optimization has been in appropriate selection of optimization standards and targets.[5] Koga and Anzai were the first to report development of a triple cone synchronizer by isuzu [6]. Later on Murata et al