The automotive industry is a "technology-intensive" industry, and for fuel vehicles, the key technologies of the "three major parts" of engine, gearbox and chassis are particularly important. Independent brands started late, the early technology is very bad, in the past 10 years, the mainstream independent car companies continue to increase the investment in technical resources and funds, in order to firmly grasp the self-developed technology in their own hands.
Judging from the current situation, independent brands have made many breakthroughs in the engine, but the better gearbox configuration is still "one color" Aisin 8AT/ Aisin 6AT, and the technical difficulty of independently developing high-quality, high-grade gearboxes can be seen.
Difficulty does not mean that no one tried, last December, by the Great Wall Motor independent research and development of the 3.0T + 9AT powertrain officially off the line, as the first domestic longitudinal 9AT gearbox, many friends are full of curiosity about it, this article we will focus on this, see how the strength of this domestic 9AT in all aspects?
First, the background of the launch of the Great Wall 9AT gearbox
Under the general trend of electrification becoming the mainstream, some people may question why the Great Wall should spend a lot of effort to develop 9AT transmissions.
In my opinion, there are three main reasons:
First, to meet the needs of its products. In addition to SUVs and cars, Great Wall's tank 300, Great Wall Gun and other off-road and pickup models have also brought good sales support, and it is also doomed that the Great Wall will not be one-size-fits-all on the internal combustion engine.
In order to enhance the competitiveness of products, but also for the follow-up development of off-road, pickup trucks and other models, the Great Wall really urgently needs a powertrain suitable for itself, and the high-power 3.0T engine is undoubtedly the optimal solution, and the only thing that matches it is the hydraulic automatic transmission (AT).
Second, it is no longer subject to supplier restrictions. Previously, Haval H9, tank 300 and other models are equipped with ZF 8AT, but the independent brand is not once or twice by foreign companies "card neck", when the original tank 300 ZF 8AT adjustment, but also need ZF engineers to cooperate, people are not willing or charge sky-high prices, the Great Wall can only consider itself unlucky. In order to get rid of the situation of being subject to people, self-developed technology is the real breakthrough point for seeking change.
Third, raise the brand image. Undoubtedly, the rise of independent brands is definitely the future trend, from the current situation of tank 300 and tank 500 approaching the price of 300-400,000 yuan, it is not difficult to see that Great Wall Motors has a determination to go upward and impact the high-end passenger car market. The Great Wall's longitudinal 9AT gearbox can be said to make up for the gap in the field of high-end gearboxes in China, and high-end product strength can naturally support the high-end brand image.
Blindly relying on external procurement technology naturally can not get more recognition, in order to support the brand's ambition and ambition, independent research and development, high-quality three major pieces of technology is the optimal solution, the launch of 3.0T+9AT powertrain is also in line with the trend, this power system will be installed on more high-end models in the future, to help Great Wall Motors launch a brand upward challenge and impact.
Second, which engines are mainly used in the 9AT transmission? Which models are mounted?
Because it is a new technology developed by Great Wall Motors, the time for mass production to go off the production line is not long, so at present, there is only a 3.0T V6 turbo engine + longitudinal 9AT gearbox, which is a form of power, which will be the first to be built on the tank 500 model. Naturally, Great Wall Motors also wants to install this power system on more high-end models as soon as possible, but what comes with it is the problem of production capacity.
The Yongchuan parts base was just completed and put into operation in December 2021, the annual output of the 9AT automatic transmission project is only 180,000 sets, and the tank 500 has reached 40,000 orders in a week before the pre-sale, and the production capacity supply of a single model can be maintained, not to mention the use of 300 tank models with monthly sales of nearly 10,000. According to the official, after the increase in production capacity, this efficient power system will be applied to more models in the future, including off-road, pickup trucks, light passengers and so on.
Third, the Great Wall longitudinal 9AT structure analysis
Mercedes-Benz 9AT as the world's first mass-produced longitudinal 9AT transmission, can be described as the "originator"-like existence, and the Great Wall 9AT transmission is also inextricably linked to him, the Great Wall high-paid R & D engineer Gerhard Henning is the main designer of the Mercedes-Benz 9AT.
Like the Mercedes-Benz 9AT, the longitudinal structure makes the Great Wall 9AT transmission also have a generous internal deployment space, so it can meet the needs of the built-in four sets of planetary gear sets, each set of planetary gear sets includes planetary wheels, sun wheels, and planetary rows of shelves, the three components are embedded with each other, and the transmission ratio is adjusted by changing the setting and combination of multiple sets of planetary gears.
The system consists of four planetary gear sets, four clutches and two brakes, with 9 forward gears, 1 neutral gear and 1 reverse gear achieved by combining the state of each clutch. The Aisin vertical 8AT also adopts the "4+4+2" structure, but it has one less forward gear than the Great Wall 9AT.
In addition, all the gears of the Great Wall 9AT are coaxial design, which reduces the friction of meshing between the gears, does not have to bear radial forces, reduces the risk of micro-deformation, and can also save the internal space of the transmission compared with the traditional biaxial structure.
Fourth, the technical characteristics of the Great Wall longitudinal 9AT
As we all know, the uneven terrain of the mountainous area makes the off-road vehicle have very high requirements for the transmission of engine torque, so the Great Wall is specially based on the off-road working conditions of the tank model, "tailor-made" the Great Wall 9AT gearbox, which can meet the complex terrain of mountains, urban areas, steep slopes, mud, deserts and other complex terrains, and achieve full working conditions load spectrum coverage.
And in the first gear can achieve locking, low gear wheel end torque is sufficient, so as to achieve better torque output. However, with the current technology, it is difficult, which requires the torque converter and friction plate durability to be high enough to ensure the long-term stability of the transmission. To this end, the Great Wall 9AT is equipped with a torque converter with flexible output, which improves fuel economy while taking into account better comfort.
At the same time, in order to improve the maximum torque, the Great Wall 9AT transmission adopts compact and efficient clutch design, intelligent integrated electro-hydraulic module and other technologies to achieve a breakthrough in transmission performance, and realizes a transmission carrying capacity of up to 600N·m under the condition of ensuring that the size of the transmission is controllable, which is more advantageous than the universal 9AT maximum bearing torque of 400N·m.
While having high performance, the Great Wall has not forgotten to reduce noise, and the internal integrated Damber shock absorber structure design makes the Great Wall 9AT have better NVH performance.
In addition, in order to meet the needs of more models, the overall structure of the Great Wall Longitudinal 9AT is very compact, with an axial dimension of 624.8mm and a weight of only 95kg, making efforts in miniaturization and lightweighting. It can match the torque requirements of different engines such as 2.0L, 3.0L gasoline engine or diesel engine, and is suitable for different models such as medium and large SUVs, pickup trucks, and cars.
In order to improve the matching and control performance, the Great Wall Transmission Control Module TCU adopts an integrated design and is directly connected to the solenoid valve, which has stronger protection performance and shorter response time compared with the traditional external TCU. And unlike the conventional separate placement of TCU, in order to protect the TCU known as the core brain of the transmission, the Great Wall 9AT gearbox puts together the electronic control components such as the TCU control unit and the spool box and is placed at the bottom of the oil pan of the transmission, which has the advantage of not affecting the internal structure even if the water floods the chassis, and has a more reliable stability.
Fifth, the commercial sale of 9AT gearbox horizontal evaluation
The 9AT transmissions currently on the market include multiple brands, including ZF 9AT and GM 9AT horizontally, and the longitudinal ones include KATE9AT, GATCO 9AT transmission, mercedes-Benz 9AT. As the "first" among its own brands, how is this longitudinal 9AT transmission developed and designed by Great Wall different from other commercially available 9ATs?
As we all know, the measurement of the quality of a transmission is nothing more than the transmission ratio range, which represents the size of the transmission range that can be allowed by a gearbox. The larger the ratio, the better the acceleration at low speeds and as slow down the rpm as possible at high speeds to achieve better fuel economy. We compared the various 9AT transmissions mentioned above, and visualized the data analysis in the form of a table: (GATCO 9AT data is missing)
Gear ratio contrast
ZF 9AT
Universal 9AT
Mercedes Benz 9AT
Great Wall 9AT
KATE 9AT
1st gear
4.713
4.690
5.502
5.288
5.85
Gear 9
0.480
0.620
0.602
0.597
0.66
Gear ratio range
9.81:1
7.6:1
9.15:1
8.843:1
8.837:1
Through the above table, it is not difficult to find that as the world's first transverse 9AT gearbox, ZF 9AT has the largest transmission ratio range, and in theory its fuel economy should be the highest, but in fact, because of the design of 4 speed gears, ZF 9AT still cannot go to 9 gears in actual use 120KM/h, which is also a point that it is criticized for, and for domestic speed limit roads, practicality is not high.
(ZF 9AT)
The Mercedes-Benz 9AT, the first mass-produced longitudinal 9AT transmission, with a gear ratio of 9.15:1, was smaller than ZF and defaulted to a 2-speed start in economy and comfort mode. Fuel economy and power can be taken into account during use, but the market response is not very good, and quality-related complaints are often received.
(Mercedes Benz 9AT)
General's 9AT transmission ratio range is only 7.56:1, theoretically speaking, the smoothness is better, low and medium speed acceleration is better, but the fuel economy in the high-speed cruise state is not dominant, and the previous generation of general 6AT compared to only 3% of the fuel economy, mainly because most of the American cars matched are high-power engines, in order to keep up with the violent power performance, naturally not economical.
(Universal 9AT)
And the Great Wall 9AT 1 gear gear ratio of 5.288, low gear under the torque output is more sufficient, the transmission speed ratio range of 8.843, gear gear ratio between the more dense, gear shift smoothness is also better, it is not difficult to see in the power performance and fuel economy between the balance has been achieved, according to the official introduction, the Great Wall 9AT in 90KM / h can hang the highest grade, high-grade 7 gears, 8 gears, 9 gears are super speed gear, gear ratio is less than 1, mainly to reduce the cruise speed and fuel consumption level.
(Great Wall 9AT)
In general, the above transmissions are common types at present, each with its own advantages and disadvantages. The GM 9AT has a consistent American style, paying more attention to power performance, while the fuel economy is lower; while ZF 9AT pays more attention to fuel economy, but the German road regulations are different from the domestic, so the 9 gears are useless; Mercedes-Benz 9AT has achieved a balance between power and fuel economy, but the quality and reliability need to be improved; the Great Wall 9AT also takes into account the power and economy, and the quality performance needs to be further tested by the market.
Sixth, what is the current market evaluation?
The most intuitive performance of the transmission is also in the consumer experience and market reputation, but 9AT because it is a new technology, only a tank 500 model is equipped with this power system, and because of the epidemic and other reasons, the delivery time has been delayed, and the consumer experience is not yet known.
However, we can take the test driving experience of the relevant media as a reference: the lightness of the power can be felt during the driving process, the movement of the gear shift is relatively small, and the reaction sensitivity is improved when driving at a low speed. This is also a common problem of 9AT, which feels smooth when driving at high speed, but on complex urban roads, the power and economic advantages brought by the 9A wide speed ratio will be reduced.
There is also the normal driving speed will be maintained at about 1500 rpm, the speed of 120KM/h when the speed reaches 2000 rpm, the overall tuning is more inclined to fuel-saving performance. Because the gear ratio of 1 gear is 5.288, the speed ratio range of the transmission is 8.843, so there will be no phenomenon of high-grade uselessness.
But from the past experience, transmissions are often good and negative, such as Mercedes-Benz 9AT and ZF 9AT, data performance is eye-catching, but the market performance is criticized, the Great Wall 9AT transmission is really feasible, but also need to go through a lot of time and market testing.
Seven, 9HAT to help hybrid layout
At present, there is undoubtedly a change in the transformation of electrification, and many people may wonder why Great Wall Motors has to spend so much effort to study a "icing on the cake" 9AT gearbox?
On the question of whether it is necessary to study the transmission of fuel vehicles in the era of electrification, the Great Wall naturally also thinks fully, so at the same time as the advent of the 9AT gearbox, Great Wall Motors also brought a 9HAT transmission, which is also the first P2 hybrid longitudinal 9-speed hydraulic automatic transmission in China.
The 9AT has a total of 3 clutches + 2 brakes, and the 9HAT is equipped with 6 clutches + 2 brakes, adding a 150kW high-power P2 hybrid motor to the 9AT transmission of Great Wall Motors, and a C0 clutch structure for disconnecting or combining the transmission and engine power, with a length of 720.8mm, with a torque bearing capacity of up to 750N·m, which can achieve full working condition load spectrum coverage.
Hybrid models have always been a very important part of Great Wall Motor's overall strategic layout, at the product level, the high-end brand - Weipai has created a full range of hybrid architecture, launched the Mocha DHT-PHEV, Latte DHT and Macchiato HEV, to achieve a comprehensive layout from A-class to D-class.
At the technical level, a series of power system products such as lemon hybrid DHT, 4N20 2.0T+9DCT/9HDCT, P4 three-in-one pure bridge have emerged in an endless stream, and a perfect layout of system power from 35kW to 320kW has been formed, and the system orientation has been perfected from energy saving to performance. The addition of the 3.0T+9AT/9HAT super powertrain will undoubtedly help Great Wall Motors to step onto a new level in the field of hybrids and launch an impact on the high-end of the brand.
Write at the end:
At the moment of electrification development, perhaps few car companies are willing to invest a lot of energy to develop transmission technology, so the emergence of Great Wall 9AT technology is indeed valuable, making the domestic gearbox reach a new height.
Whether the domestic 9AT can replace foreign technology is still an unsolved problem at present, because the product has not been delivered in large quantities, the lack of market evaluation, the specific use of how to feel, whether there is a defect, how the quality needs to be further verified, in addition, if the Great Wall chooses to close the technology only for its models to use, for a long time in the future, the independent brand may continue to live the day of external 8AT.