International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395 -0056
Volume: 04 Issue: 05 | May -2017
p-ISSN: 2395-0072
www.irjet.net
DESIGN AND DEVELOPMENT OF A TRANSMISSION SYSTEM FOR AN ALL TERRAIN VEHICLE Dr. V.K. Saini1 , Sunil Kumar2 , Abhishek Singh3, Abhishek Srivastava4 , Amit Sharma5 , Prashant Dobriyal6 1Head
, Dept. of mech. Engineering, IMS engineering college, Ghaziabad, India Dept. of mech. Engineering, IMS engineering college, Ghaziabad, India 3,4,5,6Student, Dept. of mech. Engineering, IMS engineering college, Ghaziabad, India ---------------------------------------------------------------------***--------------------------------------------------------------------2Professor,
Abstract -Design consideration, mathematical data, static
and dynamic analysis of transmission system. The main principle of the transmission system is to supply required torque and power generated by the engine to the wheels as per driver’s requirement. The aim of this work is to economically simplify the design of transmission system in order to increase its performance and safety standards. This work comprises of material selection, gear box design, Finite Element Analysis (FEA) and simulation to test against failure. Since the AllTerrain Vehicle (ATV), is subjected to uneven and irregular road condition, constant and continuous power transmission should be considered in its design. For this, a combination of Continuously Variable Transmission (CVT) and designed gearbox is used to obtain the required reduction ratio. Design of transmission system is based on tractive effort, vehicle resistances, grade ability, and maximum vehicle speed. Considering all the above factors required reduction ratio is calculated. Finite Element Analysis (FEA) is considered for design validation. Key Words: Transmission System, Gear Box, ATV, Tractive Effort, Vehicle Resistance, Grade Ability, CVT, FEA. 1.INTRODUCTION According to V.A.W Hillier & David R. Rogers [1],” Any vehicle equipped with a combustion engine as its prime mover requires a transmission system to transmit torque at an appropriate speed to the driving wheels”. Transmission system of an ATV is the one which transfers power from engine to the driving wheel. Power produced from the engine is transmitted according various load conditions. The main task of the transmission system is to use that power effectively and provide different speed & torques to the wheels according to the load imparted on the vehicle which varies from stationary to maximum speed of the vehicle. A good transmission system easily allows connection & disconnection of engine from rest of the driveline and also provides adequate fuel efficiency, fast acceleration and high speed in no time which results in maximum performance of the vehicle. According to Thomas D. Gillespie [2],” Maximum performance in longitudinal accelerator of a motor vehicle is determined by one of two Limits-Engine power or traction limits on the drive wheels. Which limits prevails may depend on vehicle speed. At low speeds tyre traction may be the © 2017, IRJET
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Impact Factor value: 5.181
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limiting factor, whereas at high speeds engine power may account for the limits”. The various types of vehicle power transmissions can be classified according to their operating principles. [1] 1. Multi-stage transmissions have a number of fixed gear ratios which can be selected manually by the driver, or automatically by a mechanical or electrical control system according to the vehicle operating status. 2.Continuously variable transmissions (CVTs) are infinitely variable b certain boundary limits achieved through hydraulic or mechanical mean. Multi-stage transmissions rely on fixed, geometrically locked elements (i.e. gears), whereas CVTs use friction locking principles to achieve the necessary ratios. This friction locking function needs an additional energy, which reduces the overall efficiency of the gearbox itself. This inefficiency is offset by the fact that, because of the infinitely variable transmission ratios.
1.1 Continuously Variable Transmission (CVT) CVT is the combination of two pulleys (driver and driven) and a power transmitting V-belt provide infinite number of transmission which varies from minimum to maximum ratio. Using CVT makes it is easier to maintain a constant angular velocity over a wide range. Its combination does not include gears directly so the engine speed can be varied widely along with the maximum fuel efficiency. Over all it results into maximizing the performance of the vehicle by using at most power produced by the engine.
1.2 Gearbox A gear box is a set of gears with its casing used in vehicle for power transmission. Power from a petrol or diesel reciprocating engine transfers its power in the form of torque and angular speed to the propelling wheels of the vehicle to produce motion. The objective of the gear box is to enable the engine’s turning effect and its rotational speed output to be adjusted by choosing a range of under and overdrive gear ratio so that the vehicle responds to the driver’s requirements within the limits of the various road conditions.
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