Both 6AT and 9AT transmissions belong to a type of automatic transmission (AT), where "AT" is an abbreviation for "automatic transmission", which means automatic transmission. This kind of gearbox uses a combination of hydraulic transmission and planetary gears to achieve automatic transmission, which is usually composed of a hydraulic torque converter, a planetary gear mechanism, a shift actuator, a shift control system, a shift control mechanism and other devices.
The main difference between the 6AT and the 9AT is the number of forward gears they each have, the 6AT has 6 forward gears while the 9AT has 9 forward gears. These gears are achieved through different gear combinations, each with a different gear ratio to suit different driving needs.
In terms of structure and working principle, there is no substantial difference between the 6AT and 9AT gearboxes, which are composed of a set of torque converters, planetary gear sets, clutches, brakes and other control structures. The difference is that the 9AT gearbox has more gears, so its internal structure and control logic are more complex.
Although theoretically, the more gears the gearbox is conducive to the power and economy of the car, but too many gears will also increase the structural complexity and manufacturing cost of the gearbox, and more precise control systems are also needed to ensure the smoothness and stability of gear shifting. Therefore, in practical applications, the number of gears of the gearbox needs to be reasonably selected according to the specific needs and positioning of the vehicle.
In general, both 6AT and 9AT transmissions are a type of automatic transmission technology, which can adapt to different driving needs through different gear combinations to achieve different gear ratios. The choice of transmission depends primarily on the specific needs and positioning of the vehicle, as well as the consideration of manufacturing costs and control complexity.