Quietly, but very fast electronics penetrates into the system of a full drive. Let's consider some modern schemes, where the electrons tending to Newton-meters.
Discotheque in transmissions in the mid-1980s, the mass models showed a differential with multi-judicially controlled electronics. The design of the geneticist was not very different from the current systems: the control unit gave the commands to the executive mechanisms to close or break the muff, the information came from the sensors on the wheels. The power and speed, the electronics became not only faster, but also smarter. For example, one of the most popular with the multi-suit "Chalex" is already in the fourth generation (detailed-ZR, 2011, No. 4). In order for the first designs to react to the spin wheel, the wheel had to be rolled on 1/8 of the revolution. Today, the coupling of the second axle creates a forethrust (even with the normal grip of the wheels on the rear wheels the 5-10% of the torque) and instantaneous reaction to the change of the situation. Multi-wheel-drive clutches, which were originally designed for passenger cars, were later on and in the saddle. On some models, such as Toyota RAV4, electronics alone distribute the thrust of the axes, allowing the driver to simply block the muff for the best terrain. Nissan X-Trail or Mitsubishi ASX provides a little more freedom: it is possible to introduce monocinoform. In some powerful sports cars, for better manageability, the electronics are embedded not only between the axles, but also between the wheels. However, this is a consignment note, and therefore, for most cars, the differential is imitated by electronic means, with the brakes being excessively fast wheels. At Land Rover, depending on the type of coating chosen by the driver, the Terrain Response system does not only manage the multi-claim muff, but also sets the pedal force and the steering wheel, engine algorithm and box. Most likely, such a scheme will soon be borrowed by others. The similar algorithms are implemented in the Peugeot 3008 transmission. Hey, aft!Ten years after the propiska of the full drive on the asphalt in his story, the next important chapter appeared. It was written by its Japanese designers, creating an active, inter-wheel differential AYC (Active Yaw Control). Two gears are built into the right-hand wheel drive: rising and decreasing speed. They are included with the multi-disk clutch of the electronics team, one by one, depending on which side the vehicle is turning. As a result, one shaft may rotate faster or more slowly. As a result, the specified path is followed instead of the expected oversteer. Like many systems, active differentials develop and adjust to the nature of a car. The active differential AYC Lancer Evolution by Mitsubishi has been designed to drive at the limit of opportunity. Honda was preparing its transmission with the electronic differential SH-AWD (Super Handling All-Wheel Drive system) for a comfortable large Legend sedan. Its purpose is to ensure the most transparent and safe manageability, effectively using the potential of the 300-strong engine. Depending on the concept of the car, the active differential can provide precise control in sports regimes or, on the contrary, to work ahead, creating maximum comfort and safety while driving. True, these structures are complex and expensive, and therefore implemented only on expensive models. The active rear differential of the Dynamic Performance Control (BMW) is similar to that of the AYC made by Mitsubishi. Only there are two upturn speeds-on the shaft of the right and left wheel. And the disc clutch does not compress the hydraulic actuators, but the electric motors. But the effect is the same: not only does the car slip any longer on the trajectory, but it also slows and touches it, especially on the mixer. Of course, the active differential works in close contact with the advanced DSC stabilization system. There are no mashups with hybrids becoming ... easier. At least as far as the 4x4 circuits are concerned. It is possible to save place and mass by removing the hand-box and carving shaft, and the rear wheels will provide electric motor. It is not necessary to make it powerful-two to three dozen kilowatts are enough to move the 1.5-ton vehicle at low speeds and to assist the petrol or diesel engine during the acceleration or the traffic on the bad road. Peugeot 3008 was the first hybrid with diesel power. Two-litre 163-a strong diesel engine leads the front wheels and 37 is a strong electric motor. It is noteworthy that the Hybrid4 transmission unit can operate in three modes: pure electric rear-wheel drive, diesel front-wheel drive and 4 × 4, when the front axle is stalled. 1 electric motor; 2-nickel metal hydride battery; 3-power control unit; 4 transmission control unit; 5-start-stop system; 6-automatic gearbox; 7 diesel engine. Of course, non-road capacities of such models are modest, but unlikely to be worse than many "parkegs" with traditional schemes. However, if necessary, it will be easy to load the rear wheels with traction. Apparently, this is why the scheme is gaining popularity. It is possible that in the coming years it will become dominant for new four-wheel hybrids. The main feature of Porshe 911 GT3 R Hybrid is the absence of used batteries. The KERS system (Kinetic Energy Recovery Systems) used in Formula One is installed instead. The Flywheel can rotate at a speed of up to 40000 rpm, accumating mechanical energy during braking, which, at the request of the driver, will be returned to the front wheels and the rear actuators of the internal combustion engine. 1-electric motor control unit; 2-electric motors; 3-high voltage cable; 4-wheel-generator; 5-wheel drive control unit. More initiativesIf there is no cardan and discards, maybe you don't need a drive? The development of the engine-wheels is no longer one year for the company Michelin. The main advantage of such a scheme is compactness, and the disadvantage is increasing the unoccupied mass, which negatively affects the driving sensations. The arrangement with the electric motors is not in the wheel itself, but in the immediate vicinity. So far, the idea of a motor-wheel is only implemented in prototypes. The main thing is that it prevents such a scheme from obtaining a ticket to life-large size and mass. But the developers of the Mishlen-Extiva Ville claim that they have solved these problems and will soon present more compact and light development. 1-Pneumachio Camera, which increases on dry basis a patch of the contact; 2-spikes with electric drives; 3-protective cover protects the mechanisms inside the wheel from stones and roughness on the road; 4-electric motor and multi-disk hydraulic brake; 5-spring suspension; 6 cap. With such a design, first, it is possible to keep the traditional suspension (and the level of production costs-thanks to the unification with other models), and secondly, each wheel has individual precise control of thrust. Which means you don't need to be a big country for a complex transmission!One close to a series of individual electric motors for each wheel made Mercedes-Benz with the hands of the AMG court. The total of four electric motors is issued by 880 Nm torque, driving the electric vehicle up to 100 km/h for 4 seconds. Battery units are located as low as possible and are equally distributed throughout the body for the best solution. 1 = power control unit; 2-high voltage battery; 3-Amortic frame; 4-two electric motors and transmission. On the one hand, the electronics lunches technical solutions, simplifying beautiful and sophisticated mechanical structures. On the other, on the contrary, it moves the usual framework and allows it to invent non-standard schemes, try different approaches, commit more bold steps. Is it not true that in the case of 4x4 transmissions this is particularly revealing?