But the non-trivial shifting mechanism inherent in this type of transmission forced designers to look for alternative ways to shift gears.

And their efforts were not in vain - the gearbox family was replenished first with automatic gearboxes, and then with other varieties - robotic, variable, sequential.

But it just so happened that an ordinary car enthusiast can only talk about mechanics and automatics with confidence. A much smaller number of motorists are aware of what a CVT or a robotic transmission is. And there are very few of those who know how the sequential box works and works. We decided to fill this gap in automotive education.

What is a sequential gearbox

The classic manual transmission, despite some shortcomings, still occupies a dominant position in the automotive transmission segment. There is an objective explanation for this - mastering the switching skills is quite simple, you just need a little practice. But the main thing is that such a gearbox gives the driver freedom of action: moving at the right speed, he can switch to any gear without restrictions. For example, after accelerating, switch from third immediately to fifth, start moving from second and even third, if there is a sufficient slope, brake sharply and engage second gear after fourth.

Of course, this cannot be called complete freedom - the selected gear must correspond to the load on the car and the speed of movement.

The sequential gearbox does not allow this. Its main difference from mechanics is the need to sequentially engage all gears, regardless of direction.

You ask, what is the point in such a transmission? The answer will be very simple: to simplify driving. There is no contradiction in this - cars with a sequential box do not have a clutch, so the driver does not need to think at all about which gear is currently engaged and which one should be engaged when accelerating or, conversely, when braking. As a result, the gearshift process is noticeably accelerated, which can be called the main advantage of the automatic transmission.

Strictly speaking, gearboxes of this type are an integral part of motor vehicles, especially older generations, where switching is carried out by a foot pedal. But even today, for example, BMW motorcycles are equipped with this particular type of transmission, which also evolves over time, becoming more perfect, trouble-free and convenient. So, seven-speed sequential gearboxes of the SMG model are currently being produced. The first generation of such gearboxes has been installed on BMW E36 M3 cars since 1996, since 2001 SMG 2 has become the main transmission of the E46 M3, and the third generation has been included in the E60 M5 package.

If, when using a manual transmission, an experienced and skilled driver spends about 0.6 seconds shifting gears (the average figure is noticeably higher), then the use of modern sequential boxes can reduce this time period by about a third, to 0.2 seconds.

Of course, for an ordinary motorist this is not critical, but for athletes such a gain in time is very significant, given that during the race you have to switch very often.

It should be considered a delusion that the SCPP is more complicated than mechanics. Automatic transmission - yes, this is indeed a very complex device, but the design of the SMG-type transmission is simpler than that of a manual transmission. If only because there are no synchronizers here, we will talk about the device of sequential boxes a little later.

Thus, the correct answer to the question of what a sequential gearbox means is this: it is a type of transmission in which gears are switched exclusively sequentially (1-2-3-4, etc.), both up and down, but but much faster, while there is no clutch pedal, and its role is played by electronics. At least in cars.

Device, features, principle of operation of the SCP

You already know about the main feature of a sequential transmission - it is the impossibility of shifting gears in an arbitrary order (or rather, the lack of the possibility of free choice). But what is the purpose of such a box? The fact is that the driver does not always have the opportunity to engage the desired gear by braking (when changing from higher to lower gear) of the car. Especially in cases where the number of gears is large (from six or more), which is typical for agricultural machinery, tractors, heavy vehicles.

Since there is no clutch pedal (but not the clutch itself), this theoretically simplifies the control of the vehicle - there is no need to synchronize the movements of the left and right legs when switching gears. Clutch control is carried out by receiving all the information necessary for this from sensors and sensors that monitor the degree of pressing the accelerator pedal and attempts to engage a certain gear. The ECU, analyzing this data, sends a corresponding signal to the actuator - a progressive SKPP block, which adjusts the speed of the car.

To have an idea of ​​​​how a sequential gearbox works, you also need to know that, unlike the mechanical counterpart, spur gears are used here instead of bevel gears. Such a mechanism has a higher efficiency due to reduced friction losses, but this reduces the torque. This disadvantage is compensated by installing gears of a larger diameter. Note that the noise level during operation of the transmission with spur gears is much higher.

Finally, another feature of the sequential gearbox is the use of hydraulic servos, the function of which is to facilitate and accelerate the switching between speeds. True, servos are also used in robotic boxes, but instead of hydraulics, an electric drive is used.

If on motorcycles gear shifting is carried out by a pedal, then in cars it is by a familiar lever or buttons (which are even more convenient to use, although this is a matter of habit). The location of the lever is either standard, on the center console, or on the steering wheel, which is typical for "Americans" and "Japanese". Such a box is designated by the letter "S" (from the word

Sequence, which translates from English as "sequence", "consecutive").

In some variations of the sequential gearbox, gear shifting can occur automatically. Typically, such SCPs can operate in three modes:

• standard mechanical, with manual gear shifting;
• sports mechanical, allowing you to speed up the switching process;
• automatic, relieving the driver of the need to shift gears (yes, there are analogies with an automatic gearbox, but there are many differences).

The principle of operation of the sequential gearbox is based on the use of which was modernized by equipping it with gears with straight teeth. Due to the presence of a hydraulic servo mechanism, the driver does not need high precision when changing the vehicle's driving mode, which further simplifies driving. All he needs to care about is to monitor the load on the power unit, making sequential shifts during acceleration and braking without the participation of the clutch pedal.

How is a noticeable reduction in the time spent on switching speeds achieved? The thing is. that on a manual transmission, when the lever is moved from one position to another, the drive mechanism rod is first tightened, then it turns, and only after that it is pressed. In a sequential box, a completely different principle is used - here two thrusts are simultaneously included in the work, one of which is pulled up, the other is immediately pressed. In other words, when switching from third gear to second at the moment of shifting, the thrust of the third gear is tightened, and the second one is pressed. As a result, the total switching time is reduced from one second (average) to 0.12 milliseconds.

Many motorists confuse sequential boxes with cam boxes. There really is a lot in common between them (spur gears of increased diameter and length, as well as the presence of end projections that serve as the basis for engagement with the cams), thanks to which it is possible to significantly reduce the switching time. Cars with a cam transmission are more dynamic, but in this case, a lot of experience is required from the driver in order to shift at the right time. Sequential transmissions do not have this disadvantage. It is for this reason that cam-type gearboxes are installed exclusively on sports cars, although no one forbids you from doing it on a regular production car. Some Formula 1 team car designers have combined the advantages of both types of transmissions in one device, but, of course, comparing the driving skills of the drivers of this super series with ordinary drivers is at least inappropriate.

We have already considered at the conceptual level the main advantages of sequential boxes. It is time to discuss the advantages of this type of transmission in more detail. So, the main advantages of using such a checkpoint are as follows:

• no clutch pedal. It turns out that this is good not only for beginners, who may have difficulty using two feet when shifting gears (situations when the brake is pressed instead of the clutch are common, and this is almost guaranteed to stop the engine). Competitors in racing competitions in cars equipped with a sequential transmission get the opportunity to concentrate on the track without being distracted by the need to coordinate the movements of their arms and legs when changing;
• switching speeds is at least three times faster. If you consider that an automatic transmission, which also lacks a clutch pedal, is much more thoughtful than a manual transmission, then sequential transmissions have no competitors in this regard. The shift itself here requires the driver to move the lever up when accelerating and down when decelerating. Extremely simple: pull the handle up until we accelerate to 4-5 gears, or down to a complete stop. No need to think about which gear is on now, and which one should be switched to;
• the absence of a time delay when switching speeds to some extent contributes to fuel economy. And although this effect is insignificant, but it has an accumulative effect - this should always be taken into account;
• modern sequential-type transmissions have already simplified the control of the vehicle to a minimum, transferring the control keys to the steering wheel. But it turns out that they offer an even more effective option - an automatic mode of operation, when the driver does not have to think about changing gears at all - the electronics and a set of sensors will do all the work for him.

A sophisticated reader will probably have a perfectly reasonable question: if sequential boxes are so good, why haven't they been widely used yet?

The answer is trivial: along with the undoubted advantages, this type of transmission also has obvious disadvantages, which in most cases outweigh the advantages. Let's describe them:

• low resistance to high loads, without which it is impossible to imagine the operation of the transmission. No matter how simple the switching takes place, even if there is a manual transmission, this must be done, given the appropriate speed mode - if you switch to third from a speed of 60-70 km / h, this will be a clear mockery of the box. Regardless of the type. The design features of the sequential gearshift mechanism (in particular, the presence of a hydraulic servo drive) significantly reduce the ability of gearbox parts to resist wear. Suffice it to say that on racing cars such transmissions become unusable literally after each stage. And this is an expensive pleasure: the cost of SKPP is much higher than that of mechanics. But for the sake of winning in speed, the teams participating in the race are forced to make such expenses. For a stock car, this is unacceptable. And although here we are talking not only about forgiveness of driving, but also about increasing power and reducing fuel consumption, all this is not in vain. The driver, as mentioned above, is supposed to switch correctly, feel his car, choose the right speed for switching from a lower gear to a higher one and vice versa. If you have little experience, mistakes in using a sequential transmission will inevitably lead to its premature failure, and the repair of such a gearbox will cost you a significant amount. So you should not buy a car equipped with a manual transmission if you do not have many years of experience in driving a vehicle with an automatic transmission and a manual transmission. It is worth considering the factor that it will not be easy for domestic motorists to change gears, the gear lever of which is located not on the central tunnel, but on the steering wheel paddles. But these are trifles compared to the fact that even with careful use, the service life of sequential boxes is many times less than mechanical and even automatic ones;
• such a transmission is also expensive to maintain, which is also due to design features. If we talk about the cost of spare parts / consumables, then the situation here is not at all rosy. And if you think that you can repair it yourself, then you are deeply mistaken here. Moreover, if you do not live in a metropolis, then you still have to look for a car service center that will take on the restoration of the SCP.

Let's also talk about the main misconceptions associated with the mention of a sequential type gearbox:

• many people think that robotic and sequential transmission are synonymous concepts. In fact, this is, of course, far from reality. Although the principle of operation of both types of boxes is really similar, there are also more than enough differences. An example is the type of servo drive: in a robotic gearbox, it is electric, and not based on the use of hydraulics. The robot box is equipped with a dual clutch to eliminate jerks when switching gears, the sequential analogue does not need this;
• there is an opinion that automatic transmission and manual transmission always work in conjunction. It is also incorrect, although such a stereotype can be explained by the growing popularity of automatic gearboxes equipped with a sports mode. In reality, the sequential gearbox does not always have an automatic mode of operation, and it is even more erroneous to assert that these types of transmission are identical. The most striking example is racing cars;
• There is also an opinion that the SKPP is an attribute of only racing cars, and certainly in combination with a cam mechanism. Yes, such a bunch is typical for motorsport, but serial cars have been produced for quite a long time, on which a sequential-type box has been successfully operated. And without a cam mechanism - it really is the prerogative of racing cars.

Scope of application of sequential automatic transmission

Initially, such boxes were indeed installed only on cars used in various motorsport disciplines. However, even today this type of transmission in auto racing has no competitors, allowing you to shift gears as quickly as possible and without an intermediate drop in speed. A few tenths of a second (strictly speaking, at least half a second) is a lot where the winner is often separated from the winner by hundredths of a second. Add to that a hydraulic shift mechanism and you get a really high speed transmission, albeit quite expensive.

But for more than two decades, manual transmissions have been installed on production cars. The BMW automaker turned out to be a pioneer here, at present, for example, the M3 / M5 models from BMW or the Mercedes-Benz C-class are equipped with such a box. Some confuse such a transmission with an automatic, calling it a “manual” version of an automatic transmission, which is basically wrong, and we have already talked about this. Owners of cars equipped with a sequential gearbox claim that driving a vehicle has become much easier, and it is not required to accurately get into gear, depending on the driving mode.

Many motorcycles are equipped with gearboxes that work on the principle of sequential gear shifting, and this technology has been in place for more than 50 years. Usually this is a foot-operated lever that has two positions: forward and backward. Neutral is located between them.

A sequential gearbox is also installed on agricultural vehicles (tractors, tracked vehicles). Here, the shift lever is also located under the feet, like motorcycles, but can also be mounted on the steering wheel.

Finally, many models of heavy trucks and other heavy special equipment are equipped with automatic transmissions, in which the number of gears can exceed a dozen - it would be very difficult to manage such a manual gearbox.

Sequential - this word is quite difficult to pronounce for a Russian-speaking person, and all because it came to us from English (sequence) and means "sequential". A sequential gearbox is most often one that can only shift gears sequentially, for example, from first to second and above, as well as in reverse order. Let's look at the principles of manual and automatic transmissions and then move on to sequential to better understand it.

It is a manual transmission that is installed on most domestic cars, so almost everyone has met it in practice, at least while driving in a driving school. Such a gearbox operates according to the following principle. The link can be set in neutral position, which is in the middle between gears. And in order to start moving, you need to squeeze the clutch pedal and engage first gear. In the process of accelerating the movement sequentially.

But the driver can start from second gear if the road surface does not interfere with smooth movement and the engine allows such a maneuver. If the car does not start, we push it and we can start the engine even in third and fourth gear. To reduce speed when turning, we can even switch from fifth to second. In other words, you must remember the main idea: in a manual transmission, you can shift gears inconsistently.

automatic box

Engineers were once tasked with making driving easier, and it was then that the automatic transmission was invented. Its appearance greatly simplified the process of driving, the driver no longer needed to choose a high-speed mode of movement. The machine itself selects the gear, and the driver controls it only by pressing the brake and gas pedals. Driving a car with automatic transmission is much easier, and no special skills are required.

However, the process did not stop, which is why a more advanced cam sequential gearbox appeared. For its functioning, the clutch pedal is also not needed, as in the automatic one, but its operation is based on completely different principles.

sequential box

As mentioned earlier, the sequential gearbox is based on the principle of strictly sequential gear shifting. And since it is built on the basis of a manual transmission, then in the course of the article we will periodically touch on the principles of operation of a manual transmission.

The first thing to remember is the lack of a clutch pedal for a sequential gearbox, and this is a definite plus for those who have great difficulty coping with three pedals. In fact, this gearbox has a clutch, but it is controlled by an electronic unit specially designed for this. This unit reads the signal from the sensors, which determine the force of pressing the gas pedal and calculate which gear should be engaged. Now this is not the task of the driver, but of the technician.

From the electronic unit, a command is sent to the checkpoint, where special sensors are installed. They receive this signal and transmit a new command to the progressive block, which contains information about the speed rhythm of the car. The progressive block is the last element in the circuit, it is responsible for correcting the engine data. It receives signals from various sensors, from the degree of pressing the gas pedal, from the switched on air conditioner, etc. Based on these data, it calculates and corrects the speed limit.

Let's dig a little deeper, consider the structural component in more detail, perhaps someone wants to repair such a gearbox with their own hands. And for this, it is necessary to know all the nuances and principles of transferring motion to the shaft.

The design of the sequential box includes only spur gears. Their use turned out to be more rational when compared with their helical counterpart installed in a manual transmission. Spur gears give out a very high efficiency, and this is due to the fact that they practically do not create friction during operation. However, they also have a drawback, they transmit less torque, so to compensate for this disadvantage, gears of a larger diameter are used.

And the last feature of the sequential gearbox is hydraulic servos, it is their presence that allows the electronic unit to produce ultra-fast gear changes. Servo drives based on the hydraulic component are confused by some drivers with automatic transmissions. And this is a very serious mistake, because they are structurally completely different: both their principle of operation and the output efficiency.

Benefits of sequential transmission

Let's take a look at what strengths this innovative gearbox has.

Instant switching

Indeed, this is the main distinguishing feature. The real transmission is swift. In order not to be fabulous, it is worth noting that the switching is about 150 ms. Such a time period is achieved due to the presence in the system of an electronic control unit and a servo drive on a hydraulic principle. What's more, there is no loss of speed when shifting! The sequential gearbox is a game-changer in motorsport.

None of the modern modifications of mechanical or automatic transmissions can stand out with such fast switching. Moreover, the car will now be much easier to keep on the roadway, because there will be practically no shaking and vibration. And you don’t have to depress the gas pedal all the way to “finish off” the number of revolutions before shifting to an upshift, as in an automatic transmission.

frugality

This point follows from the first, thanks to the thoughtful design of the transmission, fuel consumption is very economical.

paddle shifters

This technology has been around for a long time and is very popular among racers. And in a sequential gearbox, the shift speed is even higher, and the convenience is even greater.

Speed ​​mode selection

The driver can choose either automatic gear shifting and drive without thinking about anything, or manual, which is called Sport Mode.

Disadvantages of sequential transmission

Wear

A high load leads to rapid wear of this type of transmission. And the conversation is not about the sports cars that you see on the Formula 1 race track, but about ordinary cars. The fact is that the presence of an electronic control unit makes the gearbox very sensitive to loads, in other words, to untimely switching. Another proof of the statement "The more complex the mechanism, the higher the probability of its breakdown." Of course, if everything is done on time and no extra load is allowed, such a transmission will be durable.

Expensive service

We examined the design of a sequential gearbox, it contains many electronic data meters and analyzer units. That is why the maintenance cost of such a transmission is very high.

Major misconceptions

Sequential transmission = robotic gearbox

This is probably the main misconception. Yes, these two gearboxes have servos available, but in the sequential gearbox they are hydraulic, and in the robotic gearbox they are electric. And this is already a technologically different implementation.

Sequential transmission is an automatic transmission

Most drivers make this conclusion based on the fact that almost all modern cars for permanent use (not sports cars) that are equipped with such a transmission work only with an "automatic". This is the deepest delusion, firstly, there are models where you can choose automatic switching or manual switching while driving. Secondly, remember the Formula 1 races and everything will immediately fall into place.

Output

Today, the sequential gearbox is becoming more and more popular and is being installed on new models of cars and even motorcycles. Over time, this technology is improved and brought to the ideal. If we compare the first such transmissions, which went into series production on BMW cars in 1996, and modern analogues, the difference will be enormous! And if a sequential transmission, which is also cam-type, is installed on a car, then you get twice as many benefits. Most often, this technological solution is used on sports cars.

Constant experimentation to improve the mechanical transmission led to the invention of various types of transmissions. All developments were aimed at simplifying the actions of the driver at the time of driving.

One of the important steps in the modernization of the mechanical transmission was the invention of the automatic transmission. Car manufacturers have focused on the introduction of these boxes. Currently, most cars are equipped with an automatic transmission. The driver, making a trip in a car with an installed automatic transmission, does not think about switching speeds up or down. Automation performs this process without human intervention.

But the designer did not forget about the mechanical box. Constantly carried out various experiments on modernization and improvement. After numerous experiments, the problem of creating a sequential gearbox was solved. The main difference from an ordinary mechanical box is the gear shifting sequence.

Sequential - this word is not familiar to many Russian drivers and it is quite difficult for a Russian to pronounce it. The reason for this is the English origin of the word. Translated from English, it means "consecutive". A sequential gearbox is most often an automated gearbox. She can shift gears sequentially, for example, from first to second and above, as well as in reverse order.

Principle of operation

This box was developed on the basis of a mechanical box. The main difference is the use of spur gears. Therefore, the presence of the clutch pedal has lost its necessity. In the design there is an electronic control unit that performs this function. Switching speeds due to the hydraulic mechanism. The switching itself occurs in the time interval up to 150 milliseconds.

This circumstance is especially true for sports cars. Cars participating in various races, including Formula 1, are equipped with sequential gearboxes. When developing racing cars, the designers came to the conclusion that this box is the most convenient for pilots. With significant vibrations and overloads, it will be easier for pilots to get into gear using just such a gearbox.

It is worth noting that sequential gearboxes have been present on ordinary cars for several years. On cars with an automatic transmission, there is a sequential mechanism, which among drivers has received the name "manual" mode.

Peculiarities

The shift lever on cars with a sequential gearbox is located on the steering wheel in the form of a button marked S. In such cars, both automatic and manual gear changes are provided. The sequential gearbox can operate in three modes:

• Standard mechanical.
• Mechanical sports.
• With automatic switching without driver intervention.

pros

A sequential gearbox, like any other mechanism, has its advantages and disadvantages. Among the advantages, one can note the absence of a clutch pedal, which is very pleasing to novice drivers. The next plus can be considered the speed of gear shifting. And, of course, a definite plus is efficiency. Due to the speed of switching there is a significant reduction in fuel consumption.

Another plus is the ability to choose between an automatic or manual transmission. Some cars have paddles under the steering wheel that allow the driver to change gear without taking their hands off the steering wheel.

Minuses

But this box has its drawbacks. The hydraulic mechanism is subject to significant wear due to the heavy load during operation. On racing cars, mechanics repair the box after the second race. Mass-produced cars have a much greater durability resource.

When used, they do not experience the same stress as sports cars. Therefore, with proper operation, the service life of a sequential gearbox is no less than that of a manual or automatic gearbox. But if you operate such a box without thinking about the consequences, then you are guaranteed a premature failure. Will it be a hydraulic clutch drive, another unit or unit, it is not so important. The main thing to remember is that repairing a sequential box is very expensive.

Nowadays, the sequential gearbox is attracting more and more car owners. It is installed on many new models of cars and even motorcycles. The technologies of this transmission are being improved and brought to ideals. The time is not far off when not only sports cars that are equipped with a sequential gearbox, and even a cam gearbox, will enjoy a convenient transmission, but many car owners will be able to appreciate the benefits of sequential gear shifting.

Unveiled at the end of June 2015 at Goodwood, you may have noticed the presence of a sequential gearbox, which has long been an integral attribute of sports and supercars. Since some Karakum people became interested in the device and features of this type of checkpoint, I will tell you about it. Sequential gearbox differs in the possibility of only sequential shifting between gears. In other words, the driver can shift only one gear higher or lower than the one used, without jumping over the rest, as can be done in a classic manual gearbox with a search shift principle. I propose to get acquainted with this type of shift boxes in more detail and dispel a couple of misconceptions associated with sequential gearboxes.

The principle of operation of the sequential gearbox

As we have already found out, the gears of this type of transmission are switched only one by one, in a strictly specified sequence. And since the sequential gearbox is built on the basis of a mechanical one, we will make references to the manual transmission according to the principle of operation.

First of all, the sequential gearbox is characterized by the absence of a clutch pedal, which, first of all, will please drivers who are not sophisticated. This greatly facilitates driving, because constant dancing with the left foot on the clutch pedal, frankly, is an amateur matter. The clutch is not controlled by the driver, but by an electronic unit that receives a signal from sensors that read pressing the gas pedal and directly engaging a specific gear. As they say, it's a matter of technique. When the box receives a command from the electronic unit, with the help of special sensors, a new signal is transmitted to the progressive unit about the used vehicle speed. The progressive block is the last resort where the speed mode is adjusted based on various indicators: from engine speed to air conditioning.
Video demonstrating the operation of the sequential gearbox. How quickly the speed changes!

Secondly, in a sequential gearbox, spur gears are used. They give a greater efficiency when compared with helical gears from manual transmissions. This is because helical gears have more friction losses. But spur gears are also capable of transmitting less torque, so sequential gearboxes often use larger gears to compensate for this disadvantage.

And finally third distinguishing feature sequential transmission is the presence of hydraulic servo drives, with the help of which switching between gears occurs. Nowadays, hydraulic servos are often associated with a robotic gearbox, but this is not the case. The latter uses electric.
Evgeny Travnikov talks about one of the variants of the sequential box in his video:

Advantages and disadvantages of sequential gearbox

Now that we have an idea about the principle of operation of the said transmission, let's figure out what to expect from it.

Advantages:
1. High speed and easy switching between transmissions. Thanks to the presence of an electronic control unit and a hydraulic mechanism, the switching time is reduced to 150 milliseconds, which plays a significant role in professional motorsport. None of the classic transmissions, both mechanical and automatic, can boast of a more nimble gear shift. In addition, with a sequential gearbox, you will not frantically try to get to the right speed, racing with all the horsepower around the ring, when high loads and shaking with vibration interfere with keeping the car on the right trajectory.

2. No loss of speed when switching.

3. Economical fuel consumption.
The last two points are rather a consequence of the first, but we cannot but take this into account, giving due credit to the sequential checkpoint.

4. Ability to switch paddle shifters. Yes, this technology, so loved by real racers, was opened up thanks to the sequential shifting mechanism.
By the way, gamers also fell in love with this mechanism. Some even undertake to develop such boxes themselves =)

The fifth advantage could be called the choice between two modes - automatic and manual gear shifting (the so-called sport mode). But this feature is typical for automatic transmissions. And since a sequential transmission can exist independently, we will leave this advantage to certain types of automatic transmissions.

Flaws:
Here we are talking not only about the loads that the box of Formula 1 cars experiences on the race track, but also about the loads that the hydraulic mechanism can experience when switching incorrectly on civilian cars. No matter how easy it is to shift gears on a sequential gearbox, you need to do it in a timely manner. The units of this transmission are quite sensitive and wear out quickly due to the design features. After all, the more complex the mechanism, the more likely it is to break.

2. Expensive to maintain. Actually, here you can also refer to the design features of the sequential gearbox, and without further comment.

Misconceptions and Myths Related to Sequential CPR

1. Sequential gearbox and robotic gearbox are one and the same.
No, it's not. Despite the similar principle of operation, the robotic gearbox at least uses electric servos to shift between gears. And in the sequential gearbox - hydraulic.

2. Sequential and automatic transmission are inseparable.
Another misconception caused by the widespread use of automatic transmissions paired with "sport mode". However, it is worth remembering the checkpoints used in motorsport, and everything falls into place. A sequential gearbox can exist separately from an automatic transmission.

3. The sequential mechanism is installed only on fireballs and other sports cars, together with a cam box.
Undoubtedly, the duo of these two technologies provides a huge advantage on the track, but for more than a dozen years, sequential transmission has been used on mass-produced cars designed for public roads.

The use of sequential gearbox

Currently, the sequential mechanism is widely used and even managed to become a classic for some motorcycles and cars. For example, this type of transmission is typical for an old motorcycle. But a more popular application of this technology has become famous for the SMG gearboxes installed on BMW cars since 1996.

The SMG 1 and SMG 2 have been fitted to the BMW 3 Series for a long time.
A moment of nostalgia or how it was:

1-Upshift indicator light; 2-Program and transmission indicator;

3-Control lever; 4-; 5-Drive program switch (in the center console).

Main Components first generation SMG shown in the picture:

1 SMG system control unit; 2 ABS ECU; 3 Gear and program indicator (in tachometer); 4 Gear and program indicator ECU
5 Drive program switch (in the center console); 6 Control lever position indicator (in the center console); 7 Six-speed SMG gearbox with actuator; 8 SMG shift bracket; 9 Drive pump; 10 Clutch slave cylinder; 11 Clutch; 12 hydraulic block; 13 master cylinder reservoir; 14 DME control unit*
The SMG is now in its third generation and has been fitted to the BMW E60 M5 since 2005.

Translated sequensum means "sequence". A sequential gearbox can be considered a mechanical unit in which a separate device controls the clutch. That is, in a car equipped with the described gearbox, there will also be 2 pedals, as in a car with an “automatic”, but the gears must be switched manually (in some cases, automatic switching is also possible).

Principle of operation

When the gear is switched on independently and the gas pedal is pressed, special sensors inform the electronic unit, which transmits a signal to the box. Sensors are also installed in it, which already transmit their signal about the speed of the car to the progressive block. The latter, in turn, makes adjustments to the speed limit, coordinating the work of the checkpoint mechanisms. This takes into account the number of engine revolutions, the operation of the air conditioner and the readings on the instrument panel.

Gear shifting is carried out by means of servo drives (actuators), which are hydraulic on the sequential gearbox. If electric, then such a gearbox is called robotic (in practice, a box with both hydraulics and electric actuators is called robotic). The command to change gear is given by the driver in manual mode or using the on-board computer.

Features of the operation of a sequential gearbox

The principles of operation resemble an automatic transmission, however, a sequential unit is characterized by the efficiency and reliability inherent in a manual transmission. At the same time, the "robot" is much cheaper than the "machine". The main feature of the sequential gearbox is the ability to switch from a lower gear to a higher one without losing speed, which invariably drops when using a mechanical unit. On a number of modern cars, the sequential gearbox is controlled by buttons located on the steering wheel, which allows you to switch without taking your hands off the steering wheel.

Another plus for cars equipped with a “robot” is lower fuel consumption when compared with an automatic transmission. The absence of a third pedal helps beginners get up to speed faster, while experienced drivers can choose between manual and automatic shifting modes.

The disadvantage of robotic boxes is low wear resistance, which is especially pronounced under heavy loads or an aggressive driving method. Therefore, when operating this type of gearbox in manual mode, it is important to switch from one speed to another in time (you need to feel the moment). Otherwise, breakdowns are inevitable, and repairs "