Introduction And Simulation Of The New Types Of DCT Structure

Car has been updating with the development of science and technologyever since it birthed more than a hundred years ago. In order to meet thegrowing needs and increasing demands, people has been concentrating ondesigning better cars. In the eyes of modern people, better cars are equal tofaster, safer, cozier, more energy saving and environmentally friendly, easierto operate and more intelligent. Automatic transmission has greatly improvedthe ease of manipulation of the car by reducing drivers’ labor intensity,extending service life of engine and driveline and improving vehicle fueleconomy. Automatic transmission is the production by development ofscience and technology, because it rises with electronic technology andautomatic control theory. In the history of cars’ development, peoplegradually invented Automatic Transmission (AT), Automated ManualTransmission(AMT), Continuously Variable Transmission (CVT),Dual ClutchTransmission (DCT) and otherwise.Only in the few recent years has DCT been rapidly developed. Early in1939, German kégresse.A invented the DCT and tested it on a truck.However, due to technical restrictions, automatic transmissions had neitherbeen produced in quantity nor gotten people’s attention. In the1980s,Porsche applied this technique to racing cars. In2002, Germany Volkswagenapplied DCT to Golf R32and Audi TTV6, which promoted its production to alarge number. From then on the technology of DCT spread, the world’s othercar manufacturing companies and transmission corporations, such as Ford,Mitsubishi, ZF, etc., started to participate in researching and developing DCT.There are two reasons why DCT gets people’s attention: One is because theadvancement of electronic technologies provided the technical foundation for DCT. The other reason is that compared with other kinds of automatictransmissions DCT has superior performance. AT the same time DCTovercomes the power interruption in AMT gearshift, it also reminds the Highefficiency in transmission. DCT is comparable with AT’s phase shiftperformance, however with better fuel economy than the AT and CVT. Owingto the simple structure, DCT is easier to be manufactured than AT and CVT.And DCT has advantages like wide torque transmission range, light in weight,compact installation and etc.Even though DCT has many advantages over others, however it still hasdeficiencies in the people’s pursuit for the perfect performance of mechanicalproducts. In this paper, basing on the analysis of DCT’s structure andworking theory, I propose two improved structure of DCT specially for solvingthe problems of the difficulty of changing. The first new structure remains thegear layout method of the traditional structure DCT by laying two overrunningclutches in the two clutch driven disc of the DCT and the two input shafts ofthe transmission. This paper will introduce this structure and working theoryin detail. Moreover, it will prove the feasibility of new structure and its gearchanging method by establishing simulation model which based on thedynamic analysis. The simulation results also prove that compared withtraditional structure, the new one makes it easier to change the gear andcontrol the clutch and improves the performance. The second new structureadds an overrunning clutch between one of driven disc of the DCT and therelative input shaft of the transmission, which changes the layout method oftraditional DCT. Due to less than the first new structure withan overrunning clutch, the second structure to save manufacturing costs.Comparing with the first new DCT structure, another advantage is that someparts of gear could use anti-dragged brake of engine as well. This paper hasspecific introduction of new DCT structure and its working theory withsimulation model to verify its feasibility. The gear shifting is more complicated by the second new structure than the first one, however, it still easy whencompared with traditional DCT structure, which means it improves to someextent. The common feature of the two new structure are that at the sametime DCT inherits dynamic gear shifting, it also realizes less clutch slipping,reduces the difficulty of shifting control and prolongs service life of clutches.