Variator gearbox

The variator gearbox is a gearbox that does not have steps, while providing a smooth increase or decrease in the gear ratio. This feature of the variator allows it to use the engine power as efficiently as possible, increasing the dynamics of the car and reducing fuel consumption. In the fifteenth century, the legendary Leonardo da Vinci came up with a schematic diagram of the variator. However, the first car with such a transmission was born only in the middle of the last century. While it was then used on several models of cars, it found wide application only in our time, when mechanics could make its design perfect.

The variator gearbox consists of the following elements: variator transmission, unit disconnecting the engine and variator, that is, providing a neutral position, as well as the control system and the reverse gear. Modern cars operate using two types of variators: toroid and V-belt. V-belt variator contains two pulleys that are on different axes, and they are connected by means of a wedge-shaped belt. Each pulley has two conical discs that face each other with their apexes of cones. If you change the distance between the disks, the pulley diameter will also be changed. With fully interconnected disks, it is maximal, and with fully extended disks it is minimal. So 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. The toroidal variant does not involve the use of a chain or belt. It contains two shafts, which are located on parallel axes and have a spherical surface. Due to the rollers sandwiched between the shafts, the torque transmission is carried out. The gear ratio is changed by synchronously changing the positions of the rollers. Toroidal variator gearbox is used much less often than V-belt. This is due to a more complex device.

Transmission variator: mechanisms of separation

The motor and the variator can be disconnected by several types of mechanisms: electromagnetic clutch with electronic control, centrifugal automatic clutch, wet multi-plate clutch with electronic control, and also by means of a hydrotransformer. It is important to remember that due to its design features, the variator is not capable of providing reverse movement. That is why the variator gearbox is equipped with special mechanisms that are designed to provide reverse motion. Usually this role is assigned to a planetary gearbox. In modern variators, an electronic control system is usually used. The main function of the variable speed control system is the synchronous change of the pulley diameters as a result of reaction to the change in the operating mode of the power plant. Electrics also control the planetary gear and clutch.

The car, which is equipped with a variator, outwardly does not differ from the car with an automatic transmission . There are two pedals and the same gear selector . However, the driver may be confused by the fact that there are no fixed transmissions, as well as jerks or slowdowns when switching them. Variator accelerates the car confidently and smoothly, with no jolts. This psychological problem was solved by modern manufacturers. They introduced the possibility of selecting several fixed gear ratios. This is done to simulate classic transmissions. At the same time, the driver sitting behind the wheel can switch them forcibly. It turns out that outwardly such a gear box of the car is absolutely no different from the one used earlier.