What is a CVT

For many, the concept of "variator" may be new. If you also do not know what a variator is, you can say that this is a gearbox of a car that does not have steps, and the work is carried out by means of a smooth reduction or increase in the gear ratio. This feature makes it possible to use the engine power as rationally as possible, reducing fuel consumption, while providing a more qualitative dynamics of the car.

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 kind of transmission. At that time it was applied only on several models, however it became more widely used only in our time after making significant changes to its design.

So, what is a variator? It includes in its composition such a set of elements: a reversing mechanism, a unit intended to disconnect the variator and the engine, ie, oriented to ensure neutral position, variator transmission and control system.

In the work of modern cars can be used one of two types of variators: toroidal or V-belt. The basis of V-belt is laid two pulleys, located on different axes. Between them they are connected by means of a wedge-shaped belt. Each pulley is equipped with two tapered discs facing each other with their conical tops.

The diameter of the pulley is changed by changing the distance between the discs. If the discs are fully connected, then it will be maximum, and with full spreading - the minimum. Thus, it turns out that with a smooth change in the distances between the discs, a different gear ratio will be transmitted to the driven pulley.

Speaking of what a variator is, you should tell about its second form - toroidal. It does not assume the presence of belts or chains. In the toroidal variator there are two shafts located on parallel axes, while they have spherical surfaces. The torque is transmitted by the rollers, which are clamped between the shafts. Synchronous change of the position of the rollers allows changing the gear ratio. The toroidal variator is used much less often, which is connected with its complicated device.

The difference between the variator and the automaton: the mechanisms of separation

Variator and motor are separated by several types of mechanisms. It is important to remember that the design features of the CVT do not allow reverse movement. 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 gearbox.

Modern variators use an electronic control system, whose main function is to change the diameters of the pulleys in accordance with how a change in the engine performance occurs. The task of the electrician is also the control of the clutch and the planetary gearbox.

If you are interested in the question of how a variator differs from an automaton, then it can be said that there is no difference between cars with such gearboxes. There are two pedals, as well as a selector switch. But in the case of a variator there are no usual fixed transmissions, as well as decelerations and jerks associated with their switching. This kind of gearbox smoothly and confidently disperses the car, and jerking and jerking are completely excluded. Modern manufacturers have got rid of this problem by introducing the possibility of choosing from a certain number of fixed gear ratios. This is done specifically to simulate classic transmissions.

Now you know what a variator is.