CVT - gearbox with stepless transmission

Variator refers to automatic transmissions and is their main variety. Like all other transmissions, the CVT serves to transfer the force of the engine power to the driving wheels. However, it hides one feature - CVT-gearbox has no specific steps. Their number is infinite, in fact, because of what the mechanism has acquired the name "stepless variator."

The CVT transmission consists of 2 sliding pulleys, which are connected by means of a wedge-shaped belt. Despite the lack of gear, the variable transmission is considered more complicated than the simple automatic transmission. And consists of CVT-gearbox of the following devices:

1. Sliding pulleys. By their design, they are 2 two wedge-shaped "cheeks" located on one shaft. Operated by a special hydraulic cylinder. The latter compresses the disk depending on the engine speed or the signal from the central control unit.
2. Wedge-shaped belt. It is made of 2 steel tapes, on the surface of which there are metal plates. All elements are very close together. The upper part of the plate has a conical shape, and in its base there are grooves. In them, and inserted a metal tape.
3. Hydrotransformer. Serves for conversion and transmission of power (torque - N / m) of the engine. Also the torque converter promotes the smooth running of the car at the beginning of the movement. They are equipped with each CVT-transmission.
4. Differential. This mechanism distributes power to the wheels of the drive.
5. Planetary mechanism of low (rear) transmission. Rotates the output shaft in the reverse order.
6. Hydraulic pump. It is designed to create pressure of hydraulic fluid, due to which hydraulic cylinders are actuated. This tool is powered by a torque converter.
7. Control block. This, in fact, the "brain" variator. This microprocessor mechanism serves to control all transmission actuators, hydraulic cylinders including. It receives signals from electronic sensors (fuel consumption control, ESP, ABS and many others) and then decides to increase or decrease the engine speed. For this purpose, the electronic unit (ECU) sends its signal to all actuators, from which the behavior of the vehicle's movement changes.

It is also worth noting that the transmission "Nissan" CVT refers to devices with belt drive. Such devices are equipped with most modern cars. This is the most common type of CVT gearbox. Boxes with a chain drive are less common. As a rule, they are equipped with German cars brand "Audi".

Still some variators have possibility of work in a mechanical mode. Thus, the automatic box turns into a mechanical one. However, the cost of its maintenance does not decrease. The price of repairs and even the replacement of oil in the variator has always been great, which is due to the complex design of the mechanism.