Full-time full time system provides a constant transmission of torque to all four wheels of the vehicle. In other words, the engine torque shall be transmitted to all wheels continuously. The system of permanent full power can be called in its own way. For example, BMW has a name xDrive, Mercedes-4Matic, and Audi has their famous Quattro.
Full-power system device
The structure of the permanent full drive train consists of: a distribution box (distribution torque among the axles), front and rear wheel differentials, front and rear axle (s), front axle and rear axle (s).
The crestovs are needed to transfer torque from the secondary gross frames to the main gears.
And the main gear, in turn, increases the torque and passes it on the semiaxis of the wheels.
The power transfer from the motor to the wheels is carried out by connecting the engine to the axles through the differential. It is worth noting that the main difference of the permanent drive from the plug-in is that the latter has a locking of the inter-axial differential, either automatic or manual.
The two functions of the two-wheelers are the distribution of the engine torque between the driving wheels and the rotation of the semi-axis with different angular velocity. In the system of permanent full drive, two intercar differential (s) are on the front and rear axles.
Some modern 4x4 vehicles are equipped with an electronic interaxial differential. It can be used to change the ratio of transmitted torque among the axles.
Also multifunctional modern SUVs are equipped with a box that can support both the permanent full-drive mode and the mode of pluggable. Their construction includes differential and differential locking and the ability to completely disable one axis.
The permanent full drive is equipped with motor vehicles with a transverse position of motor and a check-point (a rebind), as well as those in which the engine and the carton are located longitudinally (rear linkage).
History of permanent full transmission
Before we delve into the history of permanent full power, we should turn to the history of 4x4 transmission in general. So, the entire drive system itself was used before the first cars were available. The first design appeared in 1824 on a steam-car, which was designed and assembled by British engineers Timothy Berstall and John Hill. The wheel drive was run through a system of gears and culls, which were associated with the balancing of the omnibus. This system was later used on steam locomotives.
But the British design failed. First, its weight was over 7 tons and the maximum speed of the omnibus was only four miles per hour. The long months of Brestaurant and Hill had their own children, but the steam boiler exploded.
And the first device that resembling modern differential appeared decades later, in 1883. A farmer from the United States named Emmet Bandeler patented a design of his own development. The scale model that he introduced (on the farmer's prototype simply did not have the means) had an axle that had two parts, so that the driving wheels could rotate with different angular speeds. Later, Henry Ford began to install the same system on his cars.
At the turn of the century, several more structures of full power were proposed, but they never received much distribution. For example, the Englishman Brawm Joseph Diplok proposed in 1983 a 4x4 car in which both axes were turned. And in 1900, Charles Cott showed the Cottamobile, which had a drive on both bridges. The bridges were driven by chains, and to the wheels, thanks to the hinge of the crusader. During the same period, young designer Ferdinand Porsche offered a 4x4 electric vehicle, each wheel equipped with an electric motor.
In 1903, the first vehicle with petrol engine of internal combustion appeared. The racing Spyker 60 HP had three transmissions and brakes on all wheels.
One of the most famous first off-road SUVs has become the so-called Dernburg-Wagen. In fact, it was the four-wheel-drive SUV Daimler of 1907. The "Dendurg car" was nicknamed because it was made in a single copy for Bernhard Dernburg, the head of the German colony of South West Africa (modern Namibia). This SUV has received a permanent full drive and pneumatic tyres-exactly what is important for moving across the sands of the African desert.
The first passenger car, which received a permanent full drive, was the little known Jensen FF. This is a British combustio that was born in 1967. Jensen has established a primitive cross-axial, differential (Fergusson). Of course, the buyers were not ready to use a 4x4 car at that time, which explained the low demand for FF. In four years of production, the British company managed to sell just over 300 copies.