fresh Audi quattro ultra four-wheel drive system detailed
Source : fresh Audi quattro ultra four-wheel drive system detailed
fresh, more efficient type of Audi’s quattro four-wheel drive system will be seen first on the upcoming A4 Allroad estate
Audi has unveiled a fresh type of its quattro four-wheel drive system in which the idea claims provides a critical improvement in efficiency.
The fresh quattro system uses an electro-mechanical operated multi-plate clutch along with also rear gear set in which combine to eliminate mechanical drag by completely cutting drive to the rear differential, along with also with the idea the rear wheels, when the driver only requires front-wheel drive.
To be marketed under the name quattro ultra, the fresh system abandons the widely used Torsen torque sensing system as well as the central differential along with also rear differential hardware used by Audi in one form or the some other since the inception of its original quattro four-wheel drive system back in 1980.
In its place will be a fully networked set-up capable of analysing the driving conditions every 100 milliseconds along with also automatically providing either front- or four-wheel drive depending on factors such as longitudinal acceleration, engine torque, steering angle, yaw rate, prevailing traction along with also driving style.
Set to make its debut on the upcoming A4 Allroad prior to being fitted to the fresh A5 coupé along with also second-generation Q5, the contemporary fresh quattro ultra system will initially be offered on products based around Audi’s MLB (modularen langsbau – modular longitudinal architecture) platform in combination with its fresh high compression turbocharged 2.0-litre four-cylinder petrol engine along with also seven-speed S-Tronic dual clutch gearbox.
Unlike the old mechanical Torsen-based quattro system which based its operation principally around existing traction levels, the fresh electro-mechanical system will be influenced by a much wider range of information obtained by various sensors as well as data relating to the road provided by the navigation system.
By combining This specific information, Audi says its fresh quattro ultra system can provide predictive operation by constantly sensing whether the driver requires front- or four-wheel drive along with also adapting the apportioning of drive to suit. In doing so, the fresh system will be able to run in a more efficient state than the Torsen arrangement, which will continue to be used on more powerful Audi products, including upcoming RS products by the German car maker’s Quattro division.
Mechanical developments brought to the latest incarnation of the quattro four-wheel drive system are similar those used on the four-wheel drive versions of Audi’s transverse engine products, including the A1, A3, Q3 along with also TT.
They include a fresh electro-mechanical operated multi-plate clutch mounted on the end of Audi’s seven-speed S-Tronic dual clutch gearbox. Depending on the design, the idea consists of between all 5 along with also seven pairs of clutch plates in which rotate in an oil bath. When the plates are pressed together, four-wheel drive will be activated. The contact pressure between each plate will be used to distribute drive between the front along with also rear axles.
The front multi plate clutch works in combination which has a newly developed dog gear style rear differential featuring a decoupler operated via a so-called claw clutch. When the decoupler will be closed, the propshaft along with also differential are operated to provide drive to the rear wheels therefore provide four-wheel drive.
When running in front-wheel drive, the front multi-plate clutch disconnects the propshaft. At the same time, a decoupling device within the rear differential opens to reduce friction along with also associated drag losses.
Unlike the process used by the existing Torsen torque sensing quattro system, the only rear wheel drive components engaged when running in front wheel drive are the bevel gears within the axle along with also gears within the differential – the latter of which compensate for differences within the speed of rotation of the wheels during cornering.
A passive torque vectoring effect will be provided on the rear wheels via selective braking activated by sensors within the ABS anti-lock brake along with also ESC (electric stability control) systems.
The resulting reduction in mechanical drag along with revisions to the existing S-tronic dual clutch gear box are said to provide prototype versions of the A4 2.0 TFSI quattro ultra with fuel savings of up to 0.3L/100km in everyday driving conditions.
To activate four-wheel drive, the multi-plate clutch closes to operate the propshaft. In doing so, the idea accelerates the gears within the rear differential. When they are running at a necessary speed, the claw clutch closes via pretensioned springs to provide drive to the rear wheels, at point which an electromagnetically actuated pin disengages a locking lever.
All up, the quattro ultra system will be claimed to weigh four kilograms less than the existing Torsen based quattro system.
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