CVT transmission has been criticized by everyone, its structure is very special, mainly composed of steel belt and pulley, under the action of oil pressure steel belt and pulley will be pressed, relying on the strong friction between the steel belt and the pulley to transmit torque, this structure is far less than the AT, DCT transmission of the traditional mechanical gear, so most people think that the stability of the CVT transmission is not good, can not carry a large torque transmission, as for the durability that everyone expects, the CVT transmission is completely fallen. If you want to play sports, off-road? The CVT transmission is almost out of touch with you!
The development status of CVT transmissions
No matter what netizens say, the Japanese car for the development of CVT transmission has been a personal practice, they developed the national coupe Honda Civic, matching the 1.5T + CVT powertrain, 100 km acceleration reached more than 8 seconds, the car once impressed every consumer with a sporty, young image; Nissan has developed the now more popular Tianlai, it matches the 2.0T + CVT powertrain, the maximum torque value of the 2.0T engine is 371Nm, the maximum horsepower is 243Ps, With the matching of this engine, the CVT transmission can be unscathed, and it has also been tested for a long time; if you say that the CVT transmission cannot be off-road, then look at Subaru, which off-road vehicle is not the main CVT transmission? In addition to Japanese cars, Korean cars and American cars are now also involved in the wave of CVT transmission development, like the now popular Elantra, ix25 and other models, all matched with CVT transmissions.
According to the quality control of the joint venture car, the CVT transmission is definitely not a "vase", it is really talented, it has a relatively economical fuel consumption, but also has a very smooth driving texture, otherwise the car giants will not be widely matched with CVT on their own models. After all, the performance of the car that Chinese consumers are most concerned about is durability and stability, if the durability and stability are not up to standard, what is the use of buying a CVT transmission?
Characteristics of the CVT transmission
With the continuous improvement of science and technology, the development of CVT transmissions is also very rapid, which also makes the early failures long gone.
The torque carrying capacity has been greatly improved, and the phenomenon of slippage has been avoided
In the past, due to technical limitations, the steel belt matched by the CVT transmission was always broken, until Bosch developed a steel belt with higher strength, better toughness and better resistance to low temperature/high temperature, the problem was properly solved, and now the Korean car has introduced a hinged steel belt, and the torque that the steel belt can carry has been greatly improved.
Many people have begun to complain again, under special driving conditions, the steel belt and pulley of the CVT transmission are prone to slippage, as long as there is a slip phenomenon, the surface of the taper wheel will appear dents, which are getting bigger and bigger and will never be automatically eliminated.
In fact, in order to prevent the CVT transmission from slipping, in the development of the CVT transmission, the oil pressure protection mode is specially set, as long as the TCU detects the signs of CVT steel belt slippage, it will actively increase the supply oil pressure of the transmission, increase the friction between the steel belt and the pulley, such as the owner's rapid acceleration driving conditions, cold start driving conditions, climbing driving conditions, and the oil pressure supply inside the CVT transmission will increase. Everyone should know the cold start protection mode of the CVT transmission, in this mode, the CVT transmission is always kept at a low gear ratio, so as to prevent the CVT slippage phenomenon, of which Nissan Xuanyi is a good example.
Durability and stability stand the test
In order to verify the service life of the CVT transmission, car companies have to test the durability of the CVT transmission. Durability test is nothing more than two points, bench durability test and vehicle durability test. When testing on the bench, the input speed and input torque of the CVT transmission will have some specific values, run in turn according to some test modes, and after several cycles of operation, the durability and stability of the CVT transmission are tested, and in general, the durability mode of the bench test is as high as 400,000 kilometers. For the whole vehicle, it is directly driven by a special driver, circulating back and forth in the city, national highway, high-speed and other working conditions, driving 300,000 kilometers without any faults to pass the relevant verification.
According to the driving habits of Chinese car owners, the driving mileage of general family cars is 20,000 km / year, 300,000 km can be used for CVT transmission vehicles to run for 15 years.
About the CVT transmission, I don't know what your views are? Welcome to leave a comment!