Pure Electric Vehicle Two-speed Automatic Transmission Research And Development

In the face of the global energy crisis and environmental problem, the automobile industry as the large energy consumption and air pollution maker, deal with the two problems, in addition to improving traditional internal combustion engine vehicles for energy saving and emission reduction, the development of electric vehicles is more long-term prospect and significance. Due to the limited by battery and motor technology, electric vehicles require transmission to better meet the power performance and fuel economy. With the more and more comprehensive development and widely application of the electric vehicles, automatic transmission has more advantages and loved by people.In this thesis, the design of two speed automatic transmission of pure electric vehicles with automated mechanical transmission (AMT) as a reference. The number of the shaft and the bearing of twin shaft transmission is less, so it has the characteristics of simple structure, small contour size and easy layout, and the intermediate gear transfer power only by one pair of gears, so the transmission efficiency is high and low nosie.In consideration of front engine front drvive (FF) and the smaller transmission size, transmission will be designed twin-shaft. According to the requirements of parameters and performance of electric vehicle, determine the motor torque, speed and power. The power of pure electric vehicles is from the vehicle mounted power supply and battery capacity is limited, so improve the limited driving distance is very necessary. Based on the optimal fuel economy as the goal and in the condition of dynamic constraints, by using the CYC-ECE-EUDC test in China and applying evolutionary algorithmsthe to optimize the design of transmission ratio, make the consumption of electricity at least. After determining the layout and the basic parameters, the gear of transmission, main reducer and differential mechanism can be designed, calculated and checked. After chaecked, modeling and assembling all parts of the transmission mechanism.