Analysis of the hottest depth dual clutch transmis

2022-07-31
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In depth analysis of dual clutch transmission

dual clutch transmission is not a new technology, but this year, foreign dual clutch transmission was recalled due to temperature sensor failure. At the end of the year, the listing of the sixth generation Golf equipped with dual clutch transmission, coupled with the overwhelming media publicity of Volkswagen, gave the dual clutch transmission the aura of "technology leader". In fact, is it true? In the past, the Volkswagen of the maiteng car was equipped with a 6-speed DSG dual clutch transmission, but the sixth generation Golf was equipped with a 7-speed DSG. Why? Are there any differences between the two dsgs? What is the difference? Which is better or worse? To understand these problems, we must first start from the generation of dual clutch transmission

Volkswagen is not the originator of dual clutch transmission

the dual clutch transmission was first invented and patented by Professor Rudolph Franke in 1940. At the same time, he also carried out loading test on the truck, but it was never put into mass production. Subsequently, in 1983, Porsche also invented a dual clutch transmission dedicated to racing cars, namely PDK (prosche doppel kupplu6 maximum tensile test space (mm) 600ngen). However, due to the cost and vulnerability, this technology is gradually replaced by the manual transmission

until the 1990s, foreign countries began to attach importance to this technology, and invested a lot of manpower and financial resources in the research and development of dual clutch transmission. Among them, Volkswagen of Germany and Borg Warner Group of the United States cooperated to develop a dual clutch transmission that can be used for mass production, namely DSG direct shift transmission, and carried it on many mainstream models such as Audi TT, And has been affirmed by consumers in terms of economy and controllability

dual clutch transmission is not just dsg

as the dual clutch transmission was first applied to mass production vehicles by Volkswagen, consumers will have such a misunderstanding that only DSG is a dual clutch transmission. In fact, each company has its own dual clutch transmission products, but each company has a different name

although each company has its own dual clutch transmission, at present, the most recognized by domestic consumers is undoubtedly the Volkswagen DSG. There is no way to let people let our proletariat use the dual clutch automatic transmission. However, no matter which company's dual clutch transmission, it uses roughly the same technology. The core technology is provided by BorgWarner of the United States and Schaeffler Group of Germany, and it is in a monopoly position

related information: Borg Warner, founded in 1928, currently owns two major groups of engine and power transmission, and has patents for wet clutch module technology and control module technology. It has become the main supplier of wet dual clutch transmission

Schaeffler Group (Schaeffler) is a family business from Germany and one of the most prestigious suppliers in the automotive manufacturing industry. It has three well-known brands - ina, FAG and Luk, of which Luk has become the main supplier of dry dual clutch

in order to understand the greatest advantage of the double clutch transmission, its structure and working principle must be emphasized

There are 15 conventional inspection items

structure of dual clutch transmission

take the wet dual clutch variator with six forward gears and one reverse gear as an example, which uses two clutches 1 and 2 arranged side by side, while the gears of the transmission are configured separately according to odd gears (gears 1, 3, 5, R) and even gears (gears 2, 4, 6). The odd gears are connected with clutch 1, and the even gears are connected with clutch 2. Clutch 1 is connected with a solid input shaft, and the input shaft of clutch 2 is a hollow shaft sleeved outside the input shaft of clutch 1. This structure ensures the independence of odd and even gears during gear shifting

working principle of dual clutch transmission

when the vehicle with dual clutch transmission is running in gear 1 (controlled by clutch 1), clutch 2 is in the disengaged state and does not transmit power. When the vehicle accelerates to the shift point close to the second gear, the ECU controls the automatic shift mechanism to shift the gear into the second gear in advance. When the second gear shift point is reached, the clutch 1 starts to separate and the clutch 2 starts to engage until the clutch 1 is completely separated and the clutch 2 is fully engaged, and the whole shift process ends. There is always power take-off during this shift

power shift is the greatest advantage of dual clutch transmission

from the structure analysis of Lego, many adult enthusiasts are also obsessed with the structure of dual clutch transmission. It can be learned that it is a traditional gear type mechanical transmission, which can be developed and produced by making full use of the existing manual transmission production facilities. Therefore, domestic manufacturers have developed dual clutch transmission and are willing to spend a lot of money to promote it. Of course, the double clutch transmission itself also has obvious advantages:

1. The power loss in the transmission process is small, and it also saves fuel compared with the manual transmission

2. There is no power interruption during gear shifting, ensuring power and handling

as the double clutch transmission adopts the mechanical transmission of gears (similar to manual transmission), but the electronic control mode is adopted, which is more reasonable in the selection of shift timing, so it is more fuel-efficient than manual transmission; At the same time, when shifting, the two clutch systems work together to ensure that there is always power output during the shifting process, and improve the handling and power of driving

dry/wet dual clutch transmissions complement each other and are equipped with different models

as consumers know, the current dual clutch automatic transmissions are 6-speed and 7-speed, of which 6-speed is generally wet dual clutch transmission and 7-speed is generally dry dual clutch transmission. The literal understanding is that one is wet and the other is dry. This understanding is completely correct. The wet dual clutch transmission is controlled by a multi plate clutch installed in a closed oil chamber filled with hydraulic oil, while the dry dual clutch transmission is composed of two dry friction plates and an intermediate plate. Compared with the wet transmission, the hydraulic system is omitted, so the structure is more simple

according to the comparison in the above table, the wet dual clutch transmission can withstand greater torque, so it can be matched with the engine with stronger power (maximum torque 350 nm). The dry dual clutch transmission is developed for engines with small and medium displacement (maximum torque 250 nm). The increase of gears and simpler system structure make it more efficient and better fuel consumption. The 7-speed dual clutch transmission is not more advanced than the 6-speed dual clutch transmission. At the same time, it is not a substitute for the 6-speed dual clutch transmission. They complement each other, so that they can cover a broader product line from small cars to intermediate cars, so that more models can be equipped with dual clutch automatic transmissions

the dual clutch transmission will be more widely used in the future

although the dual clutch transmission experienced the temperature sensor storm some time ago, the product itself has been unanimously recognized by consumers after so many years of market tests. With its advantages in handling, power and fuel economy, the dual clutch transmission will be applied to more models and will eventually replace the existing manual transmission. (end)

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