The first all-wheel drive transport appeared at the beginning of the 20th century. These were passenger cars, the purpose of which is to participate in race off-road and highway. By the invention, the audience was cooled and such cars did not get distribution. It seemed that the idea was died, however, at the beginning of the last century, the designers reanimated it by developing cargo all-wheel drive cars. And here the developers had a question - how to distribute the torque between the leading bridges. It was clear that the standard gearbox would not solve this problem. After a number of manipulations, a completely new unit appeared, which will be discussed in this article.

Dispensing box that she distributes why she is a dispensing box

All-wheel drive transport, in contrast to the monotrifer, is equipped with such a device as a dispensing box. Its purpose is the correct distribution of torque between the axes of the car, as well as its increase to the passage of labor-free places (not on all vehicles).

The dispensing box is installed after the gearbox or separate unit, and sometimes, and one with a gearbox.

Dressing box device

The design "Distribution" may differ depending on the type of the full drive system, however, you can note the general structural elements of the "Distribution":

1. Drive shafts for rear and front axles.
2. Lead shaft.
3. Seamless or chain transmission.
4. Lowering either downstream.
5. Inter-seed differential.
6. The mechanism of blocking the mid-scene differential.

Distribution box, types of dispensing boxes

According to the modern classification, there are such variations of dispensing boxes:

• On the placement of drive shafts (with unauthorized and coaxial shafts).
• By type of drive leading bridges (blocked or differential drive).
• By number of gears (single-stage, two-stage and three-stage).

Disposal boxes and their purpose

Consider more appointment of various nodes of "Distribution".

inter-seed differential (purpose, species)

This node is responsible for the distribution of the mid-sieve torque and allows the drive shaft to be revisted at various angular velocities, which is particularly important while driving, since the wheels pass different distances and, as a result, should rotate at different speeds. If "Distribution" is not equipped with such a node, then to provide the wheels with the possibility of rotation at different speeds can be possible only by disconnecting one axis.

It is worth noting that the inter-axis differentials are symmetrical and asymmetrical. The latter works so that the torque is divided into a certain proportion, and the first one gives it equal to two axes.

blocking Mechanism of Mechanical Differential (Types and Purpose)

For a full-fledged sale by a car of its off-road opportunities, the inter-axis differential is equipped with a locking mechanism, the purpose of which is based on forcibly forcing the wheels of both axes to rotate with a uniform speed. Depending on the variation of the mechanism, the blocking can occur or forcibly or manually.

To date, these types of locks are applied:

1. Viscosity coupling (Viscounts).
2. Differential self-locking Torsen.
3. Friction multidisk coupling.

Viscounts for blocking (dignity and disadvantages)

This is the easiest device that allows you to automatically block the inter-sieve differential. Her principle of action is: inside the Viscounts, perforated discs are immersed in silicone fluid, some discs are connected to the housing, while others - with the hub. During the slip of the wheels of one of the axes, part of the disks begins to rotate faster than others, and the silicone fluid, warming up, thick, as if gluing the housing with the hub.

The main advantage of this system is low cost. Minuses are much greater: the triggering is carried out with the receipt, which is why the vehicle can break through the axle wheels; from long work the system overheats; Differential lock is not complete; Such a node is incompatible with the ABS system.

Differential Torsen Self-locking mechanism (device, advantages and disadvantages)

This design consists of a set of worm gears - slaves and leading. The principle of operation of this device is: if all the wheels are "kept" the road normally, the differential equalizer gives the axes torque. However, when one of the axes begin to slip, the moment is moved to another axis, thanks to the strength of friction in worm gear. The ratio of effort sometimes comes to 20:80. The main disadvantage of such a solution is restrictions on the strength of the structure. Therefore, Torsen is not mounted on SUVs, its lots are crossovers.

Friction multidisk coupling as a blocking mechanism (principle of operation, dignity and disadvantages)

This is a set of friction discs that have a controlled compression ratio. Such a coupling makes it possible to distribute the moment between axes depending on the conditions of the area. If these conditions are usual, the torque is divided equally. During the slip of one of the axes, coupling discs occurs, and the differential is blocked partially either completely. To ensure work, the coupling is equipped with an electronic control system and hydraulic or electric drive. The inter-semicircle differential can also be blocked by manually by electrical, hydraulic, pneumatic or mechanical drive. Many cars have the ability to block differential or automatically or manually.

Chain gear

The purpose of this node is based on the transmission of torque on the driving shaft of the front axle of the vehicle to ensure the performance of the full drive. It consists of a drive chain and a pair of gear wheels (slave and leading). In addition to the chain transmission, the "distribution" is sometimes used toothed, which consists of cylindrical gears.