Compared with the traditional continuously variable transmission

People often read automobile magazines or promotional films of automobile advertisements. When it comes to car parameters, they will encounter a term-CVT. Ordinary people often confuse the concepts of automatic transmission and CVT. In fact, the working principles of these two transmissions are completely different. Compared with the traditional transmission, CVT has a simpler structure and smaller volume. It has neither numerous gears of manual transmission nor complex planetary gear sets of automatic transmission. Old CVT mostly uses rubber belt, but the disadvantage is that it is limited in force and easy to slip, so it can only be used on some motorcycles and mini-cars Due to the improvement of manufacturing technology, it is now also used in medium-sized cars. Audi and Nissan are the leading enterprises in this field. Taking Audi as an example, the factory has improved the rubber band of the traditional CVT, which is easy to slip back and run on the slope. Multitronic was officially launched at the end of 1999. In addition to replacing torque converter with oil-cooled multi-disc clutch to reduce power loss, there are two improvements, including the use of metal chain and pulley block with wide tooth ratio. This metal chain consists of 1025 pieces of metal and 75 pairs of knitting needles, which can bear the maximum peak torque of 300 Nm, while the traditional V-shaped steel belt can only bear the torque of 200 Nm, which is really a thousand miles a day.

In addition, the transmission ratio of Multitronic is very wide, ranging from 2.400 to 0.395. Compared with traditional gearbox, even manual gearbox, it has higher flexibility and smoother acceleration. Moreover, when adding and deleting manual transmission modes, the work becomes much easier, because the transmission ratio and radius of gears can be changed only by changing computer programs, and there is no need to change gears drastically. Therefore, CVT gearboxes can be used with many different types of engines with different output characteristics.

Another feature of Multitronic is that it is equipped with a torque sensor to ensure that the pulley clamps the metal chain properly, because excessive clamping force will offset some of the force, which will be wasted and accelerate the wear of the metal chain. Generally speaking, CVT gearbox has fast power transmission and low loss, so it starts quickly, the highest speed is faster than that of ordinary automatic gearbox, and the wave conversion process is quite stable and continuous, without sudden feeling. Driving this car, you will find that the tachometer and the pointer of the tachometer change almost synchronously, and there will be no phenomenon that the speed of the ordinary automatic gearbox drops rapidly when it upshifts.