The column materials were prepared by Arkady ALEKSEEV, Alexey VOROBYEV-OBUKHOV
OPTION - GO!
In the review of “automatic machines” (ZR, 1999, No. 11), CVTs are mentioned that are capable of transmitting significant torque.
We are talking about the development of Audi for the A6 2.8 model, equipped with an engine capacity of 193 liters. with. with a torque of 280 N.m. It was tempting to equip such a car with a stepless variator, but only no belt, even a type-setting steel one, could not stand it for a long time. In search of a solution, the designers remembered the lamellar multi-row chain. This is exactly what works in the new Multitronic variator, providing not only the transfer of a significant load, but also a change in the gear ratio in the range from 1: 2.1 to 1: 12.7. This made it possible to abandon the torque converter, and, therefore, from additional power losses. Its place was taken by electronically controlled lamella clutch.
The computer is able to recognize by the nature of the gas pedal movement which driver is “rider” or “economist” at the wheel. In the latter case, already at a speed of 60 km / h, the variator turns on the overdrive mode, that is, underestimates the gear ratio. But if you just vigorously drown the pedal to the floor, the sport mode will turn on.
At Audi, acceleration occurs at smoothly changing engine speeds, and this eliminates the “slippage clutch” effect that is unpleasant for some drivers, which is typical for conventional CVT systems. The computer responds by turning on “low gear” and on such subtleties as the presence of a trailer or a steep lift, the need for engine braking.
Another smart electronics feature is manual operation, when pre-programmed gear ratios are extracted from the computer's memory. In this case, the “automatic” acts as a six-speed gearbox with sequential shifting.