For many, the concept of "variator" may be new. If you also do not know what a variator is, then we can say that this is such a gearbox of a car that does not have steps, and work is carried out by smoothly reducing or increasing the gear ratio. This feature makes it possible to maximize the use of engine power, reducing fuel consumption, while ensuring better dynamics of the car.
The schematic diagram of this device was invented by Leonardo da Vinci in the distant fifteenth century, but only in the middle of the last century the world saw the first car with this type of transmission. At that time, it was applied on only a few models, but it became more widely used only in our time after significant changes to its design were made.
So what is a variator? It includes such a set of elements: a reverse gear, a knot designed to separate the variator and the engine, that is, oriented towards ensuring a neutral position, the variator transmission and the control system.
In the work of modern cars, one of two types of variators can be used: toroidal or V-belt. The V-belt is based on two pulleys located on different axles. They are interconnected by means of a V-belt. Each pulley is equipped with two conical disks facing their conical vertices to each other.
The diameter of the pulley changes by changing the distance between the disks. If the disks are fully connected, then it will be maximum, and with full extension - minimum. Thus, it turns out that with a smooth change in the distance between the disks, the belt will transmit a different gear ratio to the driven pulley.
Speaking about what a variator is, it is worth talking about its second form - toroidal. It does not imply the presence of belts or chains. In the toroidal variator there are two shafts placed on parallel axes, while they have spherical surfaces. Torque is transmitted thanks to the rollers that are sandwiched between the shafts. Synchronous change of position of the rollers allows you to change the gear ratio. The toroidal variator is used much less frequently, which is associated with its complicated device.
Difference of a variator from an automatic machine: separation mechanisms
The variator and motor are disconnected using several types of mechanisms. It is important to remember that the design features of the CVT gearbox do not allow reversing. That is why it is usually supplemented with special mechanisms designed to provide reverse movement. This role is usually assigned to a device such as a planetary gear.
Modern CVTs use an electronic control system whose main function is to change the pulley diameters according to how the change in engine operation occurs. The task of the electrician is also to control the clutch and planetary gearbox.
If you are interested in the question of how the variator differs from the automatic machine, then we can say that there is no difference between the cars with such gearboxes. There are two pedals, as well as a selector switch. But in the case of a variator, there are no familiar fixed gears, as well as decelerations and shocks associated with their switching. This type of gearbox smoothly and confidently accelerates the car, while jerking and jolting are completely excluded. Modern manufacturers got rid of this problem by introducing the possibility of choosing from a certain number of fixed positions of the gear ratio. This is done specifically to simulate classic gears.
Now you know what a variator is.