The CVT was invented and patented at the end of the 19th century, but the first cars with CVT were produced in the 1950s by DAF. In those years, this Dutch company produced light trucks and passenger cars. CVTs began to be used en masse in scooters and passenger cars only in the 80s and 90s.
CVT device
The variator can be attributed to one of the varieties of automatic transmissions. For the owner of a car with a variator box, the control selector and modes are no different from a classic automatic machine.
The very first variator in the history of mankind was invented in 1490 by Leonardo before Vinci. It was he who first formulated the principles of its work and made the first drawings depicting pulleys and a belt.
The variator is arranged differently. The main parts of the variator are two tapered pulleys, vertically mounted to each other. A steel belt is clamped between them. Smoothly moving along the cones, the belt steplessly changes the gear ratio between the primary (input) and secondary (output) shafts of the gearbox.
Obviously, a smooth change in torque implies a smooth acceleration of the car without jerking and jerking, as well as high, in comparison with other types of gearboxes, fuel efficiency. Many CVTs are equipped with a manual "gear" selection function. That is, such models have a certain number of fixed ranges that simulate certain speeds.
Advantages and disadvantages of the variator
One of the most important advantages of the variator is smooth acceleration and efficiency, comparative simplicity and low cost of the design. The engine is constantly operating at optimal conditions, so it does not overload and does not reach its critical points. The resource of the engine increases, the level of noise and emissions of harmful substances in the exhaust gases decreases.
There are also disadvantages: for example, the inability to carry high loads. That is why scooters and low-power city cars are equipped with variators. Although the latest developments from AUDI are capable of delivering 200 hp, the NISSAN CVT model "digests" 234 hp. and is installed on the crossover. Also, cars with a CVT transmission cannot tow heavy trailers or other vehicles without the risk of premature failure of the transmission.
On scooters, motorcycles, ATVs, jet skis and snowmobiles, CVTs are usually used with a belt made of a special wear-resistant material. On high-performance cars, a steel chain is used instead of a belt.
Also, the CVT is not adapted for aggressive driving style. Many models, of course, have a sport mode, but constant operation of the variator at the limit of its capabilities sharply reduces its resource. And, although in the "gas to floor" mode, the variator will outperform the automatic transmission, it will not pass without a trace for it.
Like models with a classic automatic transmission, cars with a CVT cannot be towed more than 50-100 km. On cars with a CVT gearbox, it is categorically not recommended to slip and, if possible, avoid off-road conditions.
The second major drawback of the variator is the difficulty in servicing. Car CVTs require replacement of the transmission fluid every 50 thousand, and the belt - every 100-150 thousand. On scooters, the variator belt is generally considered a consumable. Each variator is designed for a certain amount of transmission fluid, the level of which must be monitored. The electronics that control the variator receives data from many sensors in the car and a malfunction of at least one sensor can lead to incorrect operation of the entire variator.
