AT （automatic transmission） is composed of hydraulic torque converter, planetary gears and hydraulic control system components, through the hydraulic transmission and gear combinations through the fluid way to achieve the speed changing and torque changing. Hydraulic torque converter is one of the most important parts of AT, which consists of the pump wheel, turbines wheel and components guide. Besides,it can also transfer the torque and clutch. Automatic transmission has the advantages of easy operation, driving, reduce driver’s fatigue,it has become a direction of modern car’s configuration.
At present ,automatic transmission is popular in china, although AT automatic transmission with hydroulic torque converter will increase fuel consumption by about 10% of vehicles. And it is contrary to the current development trend of energy saving, but AT is the most mature technology as the automatic transmission in the field of transmissions.In the future, AT (automatic transmission) is still have a broad development trends and will have further enhancing of market share .
This article outlines the historical development ,classification, characteristics and basic structure, transmission diagram, working principle and the advantages and disadvantages . According to the requirements for the design of transmission, I complete the transmitting program , the gear ratio design and vehicle dynamic calculations. With the help of transmitting program.I design the Transmission torque converter, planetary line design, clutch, final drive, planetary gear mechanism’s exclusive design and calculation of geometric parameters. Every major sector of the transmission parameters of the design was checked, including the three clutches, two brake, planetary line, reducer, differential and so on. According to the design crafting of each shaft, I complete the strength calculation and lifetime calculations of the shaft and bearings.
