Examining the Effects of Continuously Variable Transmission (CVT) and a new mechanism of planetary gearbox of CVT on Car Acceleration and Fuel Consumption

چکیده مقاله

ABSTRACT Transmission system is one of the most important systems in every automobile that has a significant impact on their efficiency. Great automakers have considered Continuous Variable Transmission (CVT) systems as a superior transmission systems. Metal pushing belt and variable pulleys is one of the most popular kinds of CVT that uses in the automobiles widely because it can cause to better acceleration because of higher low ratio and better fuel consumption because of less over drive ratio. This paper shows how replacement of CVT with MT can affect in various specification of a certain vehicle (the Saipa Pride 131); in this regard torque ratio, output revolution, driving force, car acceleration and fuel consumption in the target car equipped by CVT are compared with the car equipped by MT system. Afterwards, a new mechanism for planetary gearbox of CVT is designed and its effect on expanding of range of torque ratio and improvement of car acceleration is discussed. CVT with the new mechanism can expand the range of torque ratio up to 10.58 % and increase start up acceleration up to 92 % compared with the conventional MT. Keywords: CVT, car acceleration, fuel consumption, new mechanism, planetary gearbox, Pride with CVT