The variator is a type of gearbox (gearbox). Such a device is used on vehicles such as scooters, motorcycles, snowmobiles. Recently, however, the use of a CVT has become possible in cars.
The first CVT gearboxes
The CVT transmission was first invented in 1490 and a drawing of its prototype was made by Leonardo da Vinci. The first cars with this type of gear shifting appeared in 1950 using the da Vinci concept. The variator was supplied to passenger cars of the DAF company, which at that time was producing not only trucks. After a while, the variator began to be used on Volvo, however, such gearboxes became really common in the 21st century.
CVT operation system
The variator is controlled using two pedals and a box, which traditionally resembles a conventional automatic transmission (automatic). The operation of the variator is based on the fact that there is no fixed number of gears in its system - in theory, the driver will shift the gearbox as many times as he needs to reach the desired speed. The transmission automatically changes the required number of gears as the vehicle accelerates or decelerates.
The variator is characterized by smooth gear shifting.
The variator types are V-belt, chain and toroidal. The most common type is the V-belt design, which is based on pulleys that constantly change their diameter depending on the speed reached. The pulleys are based on cones that move both towards each other and back, depending on the speed reached. A belt turns between the pulleys, which is in contact with these cones, which regulate its current position.
The belt is a specially coated steel belt with a complex section with strung steel plates. In some cars, plate chains are used, which are lubricated with a special fluid that changes its phase state under the influence of pressure.
Usually, pulleys are equipped with a hydraulic shifting system that moves parts of the first pulley and spreads parts of the second.
The variator changes the gear ratio during acceleration, depending on the control program. A motor working with a variator box always rotates at the same speed.
The variator, in spite of its advantages, has a number of disadvantages. So, among the most significant, designers note a high demand for engine resources and expensive maintenance.
Despite the unlimited number of gears, some variators can work with virtual gears, which are set by the electronics. In some cases, the variator can also be switched manually by the driver, as on an automatic machine with a sequential manual mode.
