Mechanical design of the 4 matic system. All-wheel drive Mercedes-Benz. Stuttgart Engineering Research

Four-wheel drive Mercedes-Benz's 4Matic is available in both SUVs and passenger cars. Let's talk about the history of the appearance of all-wheel drive from this company, its operating principle and types.

The content of the article:

SUVs or crossovers are often considered all-wheel drive, but passenger cars should also be included here. We have already talked about all-wheel drive. As a real competitor, Mercedes-Benz also has the 4Matic all-wheel drive system.

The history of all-wheel drive

Previously, we gave examples of all-wheel drive, where the variety of systems used began its history from primitive mechanical ones to modern automatic ones controlled by an on-board computer.

But Mercedes-Benz has one nuance: 4Matic all-wheel drive is installed only with an automatic transmission and no mechanics.

First generation of 4Matic system dates back to 1986, was first installed on a car Mercedes-Benz E-Class(W124). All-wheel drive in the car is activated automatically.

The drive is based on mechanical locking of the center and cross-axle rear differentials. The drive is controlled using two hydraulic couplings. The advantage is that when triggered ABS systems All-wheel drive is switched off automatically.

Second generation dates back to 1997, and is installed on the E-Class W210. All-wheel drive is permanent, and the inter-wheel and center differentials are free-type. The differentials are locked using a system that controls traction forces.

Third generation started in 2002 and expanded the range of Mercedes-Benz vehicles that will be equipped with the 4Matic system. The drive still remained constant. The center and cross-wheel differentials are free. Thanks to auxiliary systems exchange rate stability monitors the vehicle's movement. As a result, traction force and the need to engage or disable all-wheel drive are monitored.

Fourth generation was introduced in 2006 based on the S550. The drive was similar to the previous one, but was controlled entirely by the vehicle's intelligence system.

Fifth generation 4Matic took under its wing a large list of cars including different classes and series of cars. In 2013, Mercedes presented the CLA 45 AMG and GL550, which were equipped with a robotic all-wheel drive system. The driver does not have to choose when and how to engage all-wheel drive. The system itself decides how to transfer the load and to which axis. The engineers decided to give control of cross-country ability to an intelligent system.

Mercedes engineers do not stop there and promise to make an updated 4Matic all-wheel drive system, where the gearbox and all-wheel drive are controlled by pressing buttons rather than the usual gearshift lever.

How the 4Matic system works

Most often now you can find cars with third generation 4Matic, as they are affordable and widespread. This generation of all-wheel drive includes automatic transmission gears, cardan drives of the rear and front axles, transfer case, cross-axle differential of the rear and front axles, final drive, rear wheel axle shafts, drive shafts with constant-velocity angular joints.

Such a complex set suggests that the entire 4Matic system is a very complex mechanism, and the control is based on manual box the transfers could never have happened. The main element of 4Matic is the transfer case; it distributes torque in a stepless manner to the vehicle's axle. It also combines a planetary dual gearbox, drive shafts and cylindrical gears.

So how does the 4Matic system work? The drive shaft is connected to the planetary gear carrier, in turn, the rear axle drive shaft begins to rotate from a larger diameter gear, or otherwise called the sun gear. The front drive axle shaft is full, connected to a smaller diameter gear on one side, also called a sun gear, and on the other side using gears with a cardan drive to the front axle.

How Mercedes all-wheel drive works

The load distribution between the axles is 40% on the front axle and 60% on the rear. The function of an asymmetrical center differential is performed by a planetary gearbox. On some models, the distribution may be 45% on the front and 55% on the rear axle.

When using an automatic transmission and the 4Matic all-wheel drive system, the center and cross-axle differential locking is not provided. Thanks to the vehicle stability control system (ESP), and the traction control system (ETS) controlled by it, ABS anti-lock brakes and ASR traction control on-board computer decides when to turn on and how to transmit torque to a specific axis.

It is worth remembering that the presence of such a system in the same car model will lead to an increase in fuel consumption. According to engineers, consumption in Mercedes-Benz S-Class cars will increase by at least 0.4 l/100 km.

As for the differential lock, the ETS system is responsible for this. The operating principle is similar to electronic locking. When it is triggered, the interwheel is blocked, thereby slowing down the slipping wheel. In turn, increasing the torque to the wheel, which has good grip on the road. Thanks to this uniform and correct distribution of torque, good acceleration from a standstill, acceleration when driving on bad roads and stable control are achieved.

Video about the operating principle of 4Matic from Mercedes-Benz:

First introduced on the E-Class W124 in 1986 (1987?) and was available on models with 2.6 and 3.0 liter 6-cylinder petrol and diesel engines.

The 4WD connection was made electronically automatically based on signals from ABS sensors and was implemented by hydraulic multi-plate clutches (locking the center clutch and rear cross-axle differential, the front differential is open). When the ABS system is activated, both clutches open.

Has the following operating modes:

• 2WD, in which the rear axle was driven and the front axle was disabled;
• 4WD with a 35/65 torque distribution due to a variable degree of clutch closure (according to other sources, a differential was still installed);
• 4WD with locked center clutch and 50/50 torque split (ASD also locked rear differential if required).

Plus: some fuel economy in 2WD mode.

Cons: low efficiency of 4WD on-demand, complex and expensive design.

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Second generation 4Matic (W210 and W163, permanent 4WD)

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Implemented on the Mercedes-Benz W210 E-class since 1997 as an option (only for left-hand drive). It was present as standard on M-class models (W163), launched on sale in 1997, and on R-class. Installed only on left-hand drive versions.

It is a permanent 4WD with three open differentials and imitation of their locking using a traction control system (4ETS technology, 4-wheel Electronic Traction System). Thrust distribution 35/65 forward/backward via planetary gear.

Pros: simplicity of design, excellent adequacy and better 4WD cross-country ability.

Minus: slightly higher fuel consumption compared to 2WD due to losses in the transmission (at least 0.4 l/100 km).

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Third generation 4Matic (W203, W211 and W220, permanent 4WD)

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Appeared in 2002 on C- (W203), E- (W211) and S-class (W220) cars. It represents the development of the second generation due to the addition of electronic systems, which made it possible to increase the cross-country ability and adequacy/stability of vehicles.

4WD - permanent, all differentials are open. Imitation of blocking and general stability of the car is ensured by a set of systems (ESP stabilization, 4ETS traction control, ASR traction control, DSR descent control system and of course ABS).

Traction distribution along the axes:

• For passenger cars(except W221) and crossovers - 40/60 (according to other sources - 35/65) front/rear;
• for GL, ML and R-classes - 50/50 (symmetrical);
• for S- and V-classes - 45/55;
• for Mercedes-AMG (AMG Performance 4Matic system), such as E63 AMG, CLS63 AMG (Shooting Brake), S63 AMG (Coupe) - 33/67.

The third generation 4Matic all-wheel drive consists of:

• automatic transmission;
• transfer case;
• cardan transmission to the front axle;
• cardan transmission to the rear axle;
• main gear and rear cross-axle differential;
• final drive and front cross-axle differential;
• rear wheel axle shafts.

The central structural element of the 4Matic system is the transfer case, which continuously distributes torque across the vehicle's axles. The transfer case combines a dual planetary gearbox (performs the function of an asymmetrical center differential in the box), spur gears, and drive shafts. The drive shaft is connected to the planetary gear carrier. The rear axle drive shaft rotates from a larger diameter sun gear. The front axle drive shaft is hollow, connected to a small-diameter sun gear, and on the other hand, using cylindrical gears, it is connected to the front axle driveshaft.

1 - automatic transmission, 2 - transfer case, 3 - cardan transmission of the front axle drive, 4 - main gear and front cross-axle differential, 5 - drive shafts with constant velocity joints, 6 - cardan transmission of the rear axle drive

1 - drive shaft, 2 - rear axle drive shaft, 3 - planetary gearbox, 4 - spur gears, 5 - front axle drive shaft

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Fourth generation 4Matic (permanent 4WD)

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It was introduced on the 2006 S550 4Matic and later on the W204.

Is further development 2nd and 3rd generations based on more advanced electronics. It uses a cylindrical differential, “locked” by an uncontrolled double-disc clutch, which distributes the supplied torque between the axles in a 45/55 ratio in favor of the rear wheels. When accelerating on a uniform slippery surface, the clutch locks the center differential, adding stability to the car. If the difference in torque between the front and rear axles exceeds 50 Nm, the clutch slips - for example, in corners. Traction control is provided by the 4ETS system using service brakes. The ESP, ASR and 4ETS systems in the new system are calibrated to respond as late as possible, allowing maximum engine power to be realized.

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Fifth generation 4Matic (4WD on-demand)

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Introduced in 2013 on the CLA 45 AMG and Mercedes-Benz GL 500, it is a 4WD on-demand (that is, not permanent, but plug-in) on a front-wheel drive architecture with a transversely mounted engine at the front.

The front and rear differentials are open, there is no center differential. The set of electronic systems is the same; imitation of locks is also provided by 4ETS. The PTU (power take-off unit) unit, built into the robotic box 7G-DCT dual clutch transmissions. The PTU turned out to be very compact, and it shares a lubrication system with the box, due to which 25% of the weight was saved.

Under normal conditions, torque is distributed between the front and rear axles in proportions from 100/0 to 50/50. So, when accelerating a car with a full load at a speed of 50 km/h, the ratio changes to 60/40, when cornering quickly it becomes 50/50, when the front wheels lose traction - 10/90, in case of sudden braking with ABS - 100 /0. Redistribution of torque is achieved due to a variable degree of compression of the interaxle coupling.

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Other options

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M.L.

Permanent 4WD with three free differentials, imitation of differential locks by the 4ETS system. Triggers at speeds up to 60 km/h, and if necessary works up to 80 km/h. Borg-Warner 44-06 transfer case with push-button 2.64:1 reduction gear. When downshifting, the center differential is rigidly locked.

G-class 461…-1991

4WD part-time (hard-wired), manually hard-locking front and rear differentials.

G-class 463 1991-…

Permanent 4WD with three differentials and a 2.16:1 reduction gear. The differentials are rigidly locked using buttons on the instrument panel; you need to drive a few meters to activate the locking.

I continue to talk about incomprehensible abbreviations on various car models, and it just so happens that this detailed article will be about Mercedes (in the first one). However, today we will talk about such a concept as 4 MATIC. This inscription can be found on some modifications of the concern, for example GL, ML, and even on the C-class. So what does this mean and why is it applied to the body? Read on...

First, a little definition.

4 MATIC - This is the designation of all-wheel drive on Mercedes cars. If you decipher this inscription, it turns out - 4 Wheel Drive and Automatic - 4 wheel drive and automatic transmission.

As you can see, this is almost the designation 4 X 4 on our domestic cars, with only one difference that an automatic transmission is used, and for Mercedes it can be a torque converter automatic or a robot.

Three generations 4MATIC

AT the dawn of the appearance of this system, and it was 1986, joint engineers of Mercedes-Benz and Steyr-Daimler-Puch, the first generation of this drive was invented.

First generation

It was first installed on the W124 model (modern E-class), where all-wheel drive and automatic transmission were first used. It should be noted that there was no permanent all-wheel drive, but a so-called “plug-in” one. All 4 wheels were engaged by locking the center and rear cross-axle differentials. But the first generation 4 MATIC electronics controlled two hydraulic couplings. The first pros and cons of the device immediately emerged.

pros :

• When there was no need for all-wheel drive, it only worked rear axle, which saved fuel.
• Accordingly, the service life of the structure increased.
• The couplings were made of high-strength materials, which practically did not wear them down when the wheels slipped.

Minuses :

• The plug-in drive turned out to be not as effective as compared to the permanent one.
• Off-road capabilities were, to put it mildly, not impressive.
• The design turned out to be complex and very expensive; if it broke, you had to fork out a lot.

Therefore, Mercedes engineers worked on the second generation, which ended up being very different from the first.

Second generation

Later in 1997, the second generation 4 MATIC was presented on the W210 model. This system turned out to be more durable and productive; there were a lot of differences.

• This is permanent all-wheel drive, not automatically connected.
• Differentials (center and cross-axle) were no longer included mechanical interlocks. The 4ETS (Electronic Traction System) traction control system was installed here for the first time, which practically eliminates blocking altogether.

What benefits did this bring?

• The design was simplified, and therefore repairs were cheaper.
• The permanent drive did its job, regardless of wheel slip, that is, it felt confident both on dry roads and off-road.
• Off-road performance has improved significantly (again, if you don’t take passenger cars, here all 4 wheels gave confidence on the track when overtaking, turning, etc.)
• Great job with the automatic transmission.

In general, the design was a success, it was a kind of “work on mistakes”, and from now on 4MATIC will only be “permanent drive”.

Flaws - there are not many of them, if you only consider that fuel consumption has increased compared to the first generation, and now the entire structure is wearing out, that is, it is always constantly working. However, as Mercedes engineers assure, the resource here is really large.

Third generation

Appears in 2002, immediately on a large number of C, E, and S class cars. The developers did not abandon the successful second version, but made it “smarter”, forced “4ETS” to work together with such a system as “ESP”.

The essence is very simple - now so-called free differentials are being used in the design, which work in conjunction with the electronic ESP system. Control over the road and off-road is now almost complete:

When one wheel slips, the system begins to “stop” it, transferring the increased speed to the other wheels, which are in better gear.

The advantages of such a system are obvious - the cross-country ability has increased by about 30 - 40%. Control over the road at high speeds (slides, sharp turns, etc.) has also increased. It should be noted that 4 MATIC has won many awards.

Torque distribution

It is important to note that this drive can automatically adjust and deliver unequal torque to the wheels.

For example - Cars(except for the luxury S-class) have a ratio of approximately 35/65. 35% goes to the front wheels, but 65% goes to the rear wheels.

SUVs (SUVs) GL, ML and R class have an equal ratio of 50% to 50%.

Luxury cars (S-classe) - set to a ratio of 45% (front) and 55% (rear).

This torque ratio has been verified by many tests, as well as by the structure and features of the body. It is these indicators that make cars more stable, safer and more comfortable to drive.

4Matic all-wheel drive system, which is officially registered trademark, was developed several years ago at Mercedes-Benz, and is now installed on several models of passenger cars. Cars with 4Matic all-wheel drive are equipped exclusively with gear shifting.

The 4Matic all-wheel drive system is designed to give the vehicle road stability and controllability in all situations: when starting to move, when cornering, on snowy, icy or wet road surfaces, as well as during execution.

The 4Matic system transmits torque from the car engine to all wheels simultaneously, but distributes it in different proportions. For example:

• for all passenger cars except S-class – 40% on the front wheels and 60% on the rear wheels;
• GL, R and ML class – 50/50;
• S-class - 45/55.

The 4Matic all-wheel drive has one very interesting feature: The car now does not have cross-axle differential systems or a center differential. Instead of these systems, it is fundamentally installed new system Electronic Traction System (4ETS), which controls traction force. It is this system that prevents the car’s wheels from slipping on slippery road surfaces.

As soon as a wheel begins to try to slip, the 4ETS system automatically increases torque simultaneously to the remaining wheels that have good grip. Therefore, a car equipped with the 4Matic system always has good grip on the road and a large reserve of traction force.

4Matic device

The 4Matic system includes the following devices:

1. automatic gearbox;
2. transfer case;
3. cardan transmission to the front axle;
4. on the rear axle;
5. and rear cross-axle differential;
6. main gear and front cross-axle differential;
7. rear wheel axle shafts.

Diagram of the 4Matic all-wheel drive system:
1 — automatic transmission; 2 — transfer case; 3 — cardan transmission of the front axle drive; 4 — main gear and front cross-axle differential; 5 — drive shafts with constant velocity joints; 6 — cardan transmission of the rear axle drive.

Central structural element The 4Matic system is a transfer case, with the help of which torque is continuously distributed along the axles of the car. The transfer case consists of:

• drive shaft;
• rear axle drive shaft;
• planetary gearbox;
• cylindrical gears;
• front axle drive shaft. The role of an asymmetrical center differential in the transfer case is performed by a planetary gearbox.

4Matic transfer case diagram:
1 - drive shaft; 2 — rear axle drive shaft; 3 - planetary gearbox; 4 - cylindrical gears; 5 — front axle drive shaft.

The innovative ESP system, which is fully integrated into 4Matic, makes the system even more efficient. Since the system receives complete information from many sensors about the speed at which the wheels rotate, the angle of rotation of the steered wheels, the yaw rate and lateral acceleration. This data is calculated by the system’s built-in microprocessor and makes the vehicle’s trajectory optimal.

If the driver has set a course and the car deviates from it, the 4Matic system intervenes and adjusts the amount of torque or braking torque. The interaction of the 4Matic and ESP systems is unique today. The car is always stable and moves along the optimal trajectory.

Video:

All. Good luck to everyone on the roads!

Many motorists regard all-wheel drive as synonymous with all-terrain vehicle capability. It is no secret that the distribution of traction on four wheels increases the car’s traction with the road, thereby reducing the possibility of slipping, as well as increasing the controllability and directional stability of the car even on slippery roads.

All-wheel drive from Mercedes

Until the eighties of the last century, all-wheel drive, not on SUVs, but on simple cars, was regarded as a kind of technical curiosity.

An all-wheel drive transmission is not only additional structural components that add weight to the car, but also a system that makes the car noisy and sensitive to various vibrations.

All-wheel drive requires certain funds for maintenance, and the increase in the weight of the car and the mechanical losses of additional components lead to inefficiency compared to similar machines on one axle.

The developers of the Mercedes company decided to abandon the services of a long-time partner and invented their own all-wheel drive, as they considered this development a very serious matter.

Permanent all-wheel drive complex Mercedes 4 Matic(Formatik), which connects when necessary, was able to provide maximum traction of the car’s wheels on icy, snowy, wet and bad roads.

Features and Benefits of 4 Matic:

• maintaining maximum safety thanks to the constant activity of the system, which ensures an immediate response to difficult conditions;
• the harmonious combination of Formatika with the engine and gearbox provides excellent car dynamics;
• high efficiency of 4 Matic, thanks to the use of additional electronic systems that provide record traction use and maintain vehicle stability;
• unique ability to maintain traction.

The principle of operation of the 4 Matic is quite simple at first glance, where the rear wheels become the driving wheels on a good road. Well, in the event of slipping, smart automation sends a signal to the main computer, which engages the multi-plate clutch, redistributing torque to the front wheels. As practice shows, this system turned out to be no worse than a full-fledged all-wheel drive transmission, the only disadvantage of which is, perhaps, its high cost and rather complex design.

New generation 4 Matic from Mercedes

In 2013, Mercedes developers presented the world with the new fifth generation of the 4 Matic system with various variations of all-wheel drive transmission.

Next generation 4 Matic from Mercedes manufacturers is a completely new design. If previously the power of the rear axle was transferred to the front, now the principle of operation of the connected Formatic is somewhat different.

The developers themselves regard their work as an entry into new level. And they are proud that they were able to achieve the optimal balance between energy use, dynamics and safety. The fifth version is not a replacement, but an addition to previous versions of Formatics.

Under normal conditions, the car drives exclusively on fuel economy. front wheel drive. If you encounter difficult conditions, the system automatically transfers torque to the rear wheels, and when exiting, the power transfer occurs in the opposite direction in a matter of minutes.

The new all-wheel drive system has the following advantages::

• reduced system weight;
• high efficiency;
• high efficiency.

In conditions of understeer or oversteer, that is, if the car does not fit into turns or skids, the traction torque is distributed so as to achieve maximum stabilization of the car on the road. If the measures taken are ineffective, adaptive electronic system stabilization or traction control system in combination with the Formatik system to maximally keep the car on the desired trajectory.

The new drive is another addition to the previous 4 Matic variants. Now each class will have its own optimal 4x4 drive option, from CLA to SUVs. New structure The format is designed to provide maximum energy savings combined with excellent dynamics and high safety.