Sequential gearbox device. Sequential gearbox: classification and principle of operation. Advantages and disadvantages of sequential gearbox

The automotive industry is developing extremely fast. Every day there are new technologies that turn the minds of ordinary motorists. A good example is the evolution of transmission.

The manual transmission was the first to be invented, followed by the automatic and the sequential gearbox. These three stages of development took about a hundred years. Naturally, in the process, branches and specific products appeared that had a narrow range of applications.

Attention! In a number of sources, the sequential box is called robotic.

Sequential boxes are installed on racing cars, trucks and motorcycles. Their main difference from standard manual transmissions is sequential gear shifting. Simply put, the driver does not waste time manipulating the lever. In addition, the system itself chooses the optimal moment for the transition. Thanks to this, productivity increases several times.

Attention! If the race will be attended by two cars completely identical in technical specifications, except for the gearbox, then the one with the sequential system will win.

The video shows, using the example of a gearbox on a Honda, how the gearbox works:

During the period of evolution of the transmission, many machines were produced, working at the expense of the machine and mechanics. Each of these systems has its own characteristics, which in one way or another are reflected in the sequential box.

A mechanical box is installed on almost all domestic cars. Its advantages include high reliability and ease of maintenance. In addition, the mass of the structure itself is much less than that of an automatic transmission.

Due to the simplicity of design in production, a manual transmission is much cheaper than an automatic transmission. Also noteworthy is the high efficiency. The main disadvantage is the high complexity of operation for a beginner.

In turn, the automatic transmission is easy to operate and does not require long training to quickly switch. Also, thanks to her, the engine runs optimally. Because of this, there are no overloads.

Historical information about the sequential box

The sequential box is often used by BMW designers in their cars. The first implementation took place in 1996. Then the E36 M3 model acquired a similar system.

Attention! The modification of the sequential box was called SMG 1.

For five years, drivers have been able to appreciate all the advantages of the sequential box. As a result, in 2001, the lineup was replenished with the SMG 2 system. E46 M3 cars are equipped with it.

The E46 M3 concept was a real hit. Moreover, the reviews of motorists were more than positive about him. Finally, in 2005, SMG 3 appears. In it, the time required for switching has become even less.

Sports type M

This sequential box is considered the latest innovative solution. It has 7 steps. Prior to this, no automobile concern was able to achieve this figure.

The main advantage of the SMG's seven-speed sequential gearbox is that it allows the driver to choose between comfort and sport modes. Of course, such devices are installed only on powerful cars.

Principle and device

The easiest way is to compare a sequential box with mechanics. Moreover, they have almost the same base. The main difference is in the gears. Here, instead of oblique teeth, there are straight ones. In the design itself, there is no cohesion as superfluous.

Attention! The control unit is responsible for shifting gears.

The switching itself takes place hydraulically. Thanks to all these features, the sequential gearbox is often installed on racing cars. The common denominator of all these upgrades was that the gearbox ceased to depend on vibrations. More precisely, the rider does not need to spend time looking for the right gear.

When comparing a conventional gearbox and a sequential gearbox, special attention must be paid to the moment of shifting thrust. As soon as this happens, the actuator rod is pulled up, rotated and pressed. This happens in the standard system, but not in the serial system.

In a sequential box, when switching, one rod is pulled up, and the other is responsible for pressing. This reduces the time interval. This technical innovation has allowed us to reach a new level of performance.

What is a sequential gearbox:

Features of functioning

The shift lever in cars that have a sequential gearbox is located on the steering wheel. In some modifications, you can see the buttons. The system operates in the following modes:

• sports;
• standard;
• automatic.

The first two options use mechanics. It is not surprising that many novice drivers prefer to drive with just such a gearbox. As soon as they reach the required level of driving skill, the full range of system capabilities will open up for them.

Advantages and disadvantages

Each system has unique features that determine its operation. The sequential box was no exception. Its main advantages include:

• ease of management,
• high gear shifting speed,
• economy,
• several operating modes.

A sequential gearbox can be either manual or automatic. Unfortunately, it was not possible to do without shortcomings, and the disadvantages of the device include:

• unreliable design;
• rapid wear of all parts;
• the need for constant maintenance.

As an example, you can take a conventional racing car with a sequential gearbox. After each race, it is sorted out by the masters. This is a prerequisite for the car's admission to the next race.

The sequential gearbox can be called the result of a long evolution of the transmission. It combines the advantages of manual transmission and automatic transmission. As a result, such a system provides excellent acceleration potential and minimizes fuel costs. Also noteworthy is the ease of use.

As the situation on automotive forums shows, many motorists are very interested in the question of what a sequential gearbox is. We will immediately answer that this is often a manual transmission (although automatic options are increasingly common today), the main feature of which is the ability to shift gears only with strict sequence up or down.

Thanks to this, the driver does not have to think about which gear to activate - he simply raises or lowers it. But this type of gearbox also has other features, so below we will take a closer look at what a sequential gearbox means.

So, the main feature of the sequential gearbox is the lack of the possibility of a free choice of gears and jumping over several at once. The need for such a gearbox arose due to the fact that the driver does not always have time to select the desired gear and brake to shift it. By the way, such improved manual gearboxes are used not only on cars, but also on motor vehicles, where switching between gears is often carried out by foot.

If we are talking about sequential boxes installed on cars, then here they will be distinguished by the location of the control center. The lever (and sometimes even more convenient and responsive buttons) is located on the steering wheel for convenience vehicle, while it will be necessarily marked with a special marking "S", which indicates the presence of a sequential gearbox on the car.

Important!On some cars with a sequential gearbox, shifting between gears can be carried out not only manually, but also automatically.

Such a gearbox has three main operating modes that can be activated in parallel with the main gears:

Standard mechanical.

Mechanical sports.

Auto when the driver does not need to shift gears at all.

The last feature of a sequential gearbox is that when it is installed on a car, there is no need to install a clutch pedal. This not only makes driving easier, but also allows you to operate the engine in standard conditions, regardless of driving style and experience of the driver.

Where are sequential automatic transmissions used?

Sequential automatic transmissions today can be found mainly on racing cars, as they are quite expensive, and in their intended use are fully adapted to these types of cars. Thanks to this gearbox, the driver gets the opportunity to increase speed and switch from gear to gear without the slightest slowdown, which is especially important for competitions. If, in addition, such a box will work on the basis of hydraulics, this will further increase the responsiveness of the car.

As for the usual passenger cars, then the sequential gearboxes installed on them are popularly referred to as the "manual" mode of operation automatic box gears. However, even in this embodiment, driving is considered lightweight and does not require the driver to accurately hit a specific gear. Among the production cars on which such boxes were installed, it is worth mentioning:

BMW M3.

mercedes benz C class.

But in fact, sequential checkpoint is more common than it might seem at first glance. As mentioned above, such boxes are installed on motorcycles, where there are usually only two gears. As for the neutral position of the gearbox, on motorcycles it is usually fixed between the first and second gears. The sequential gearbox has become even more widespread in the design and creation of agricultural tractors, on which the gear shift button or lever can be located both under the driver’s feet and on the steering wheel. Sequential gearboxes are also found on heavy vehicles.

The device and principle of operation of a sequential gearbox

The basis of such a gearbox is the familiar mechanical transmission, which has been improved and equipped with spur gears instead of helical gears. A significant design difference of the sequential gearbox is the absence of a clutch pedal, which is compensated by the installation of an electronic control unit (it is also responsible for gear shifting in the automatic mode of the gearbox).

Shifting gears thanks to the hydraulic mechanism is as fast as possible and does not require precision, as in conventional gearboxes. All that is required from the driver while driving a car with such a box is an assessment of the complexity of the road and the load, which is transmitted to car engine. To make it easier for him to work, it is worth gradually increasing gears. If low speed maneuvering is required, the gears are downshifted based on vehicle behavior and engine response.

Sequential or cam gearboxes?

It is also worth mentioning the existence of cam gearboxes, which in their structural features have much in common with sequential. In particular, they are united by the presence of spur and long gears with end projections (for which the cams cling), thanks to which such gearboxes allow you to switch from one gear to another as quickly as possible without reducing the speed of movement.

However, it is almost impossible to determine which gearbox is better. For this reason, the designers simply combined them into one mechanism, which is already used today on racing cars that take part in Formula 1. So it is more correct to call a cam gearbox a good alternative to a sequential gearbox.

The advantages of using such a box on cars and other modes of transport

We have already figured out what a sequential checkpoint is. However, let's summarize all the advantages of using such a gearbox in different modes of transport:

1. No clutch pedal. This feature is most relevant for those who are just learning to drive and can confuse the pedals. In addition, the lack of clutch makes it easier to control the car in difficult racing conditions, when it is important for the driver to concentrate not on the force on the pedal, but on the track.

2. Transfers are switched as quickly as possible. In this, no other type of gearboxes can compare with sequential gearboxes. This advantage should also include the fact that when you press the gear lever up or down, the driver does not have to think about which gear to shift the lever into. He just raises or lowers them.

3. Automotive designers also note that the lack of deceleration during the transition from one gear to another also has a positive effect on fuel economy.

4. Work on two modes - automatics and mechanics. Despite the fact that the designers have already simplified the process of driving a car with a mechanical sequential gearbox by transferring the buttons to the steering wheel, in some situations the driver may refuse to control the transmission altogether and entrust this task exclusively to the electronic control unit.

Disadvantages of sequential gearbox

The sequential gearbox is not without a number of disadvantages, and they are mainly associated with the design of such a gearbox. The first thing to think about when buying a car with such a gearbox is accelerated transmission wear. Do not forget that in extreme and too harsh operating conditions, the hydraulic mechanism wears out quickly and can fail at a very inopportune moment. For this reason, racing cars have to be completely sorted out and parts changed literally after each race.

It was also mentioned above that thanks to the installation of sequential gearboxes on serial cars, their power is significantly increased. But there is also a pitfall here: this can be achieved only if it is correct and timely to switch from lower to higher gears and vice versa. If the driver feels bad about his car and his needs, this again can lead to failure of all elements of the hydraulic transmission. At the same time, the restoration of such a system will cost the car owner very expensive.

In this regard, driving a car with a sequential gearbox is recommended only for experienced drivers who have left their own and on mechanical box, and on the machine. Lack of experience in driving a car can adversely affect its condition.

Translated from English, sequential is translated as a sequence. Therefore, a sequential gearbox means only sequential gear shifting. This principle of operation is to influence the control of the foot (an example is a motorcycle), for a quick switch - a sports car; in the case of a large number of gears, the selection of which by shifting the lever is not very convenient - this is a tractor, trucks. Most often, switching occurs due to the displacement of the control from the neutral position. While the principle of operation of a classic gearbox is to independently select a gear.

Sequential gearbox

Development of the sequential box

What kind of transmission boxes have not been created in the entire history of the automotive industry. So the creation of a sequential transmission did not pass by. Most often we hear manual or automatic transmission, but it is worth understanding that this is not the case, as there are many more options for shifting gears.

There is a difference between these checkpoints that is worth understanding. Take, for example, an ordinary car with a manual transmission. In this case, the driver independently makes the choice of speed transmission. That is, having accelerated, he has the opportunity to switch from third speed to fifth, or, conversely, when braking, switch from fifth to third. This mechanism can also be called a search mechanism, since the inclusion of gear speeds is completely dependent on the driver. Once again, I would like to note that the transmission can be any, the most important thing is that it should be in line with the driving mode and the loads on the car.

But as for the owners of a sequential gearbox, they are deprived of such an opportunity for free switching. This action can only be performed one value either up or down. That is, the shift will look like this: two-three-four or seven-six-five, which is typical for BMW motorcycles and for M1-M motorcycles. It is impossible to achieve another switch on such a box.

Sports type M

More recently, a seven-speed sequential gearbox has been developed. This is the first model of a 7-speed SMG gearbox in the global automotive industry. Due to its ultra-fast shift times, combined with the power power unit it allows its owner to make his own choice of sporty or comfortable riding style.

Historical information

This box has already managed to become traditional for BMW cars. Already in 1996, SMG 1 began to be installed on the E36 M3 model. In 2001, the E46 M3 models were equipped with SMG 2. And already in 2005, the SMG 3 gearbox was installed on the E60 M5 model. What distinguishes this gearbox from previous models is a noticeable reduction in gear shift time.

Seven-speed sequential gearbox for BMW

This third-generation transmission model is equipped with individual shift linkages, allowing for a noticeable reduction in linkage at the time of shifting. How could this happen?

How does the switching process work?

Comparing a conventional gearbox with a sequential SMG 3, you notice that in a conventional gearbox, at the moment of shifting, the gear shift rod is pulled up, after which it turns and is pressed. In the compared device, everything happens differently. Here it turns out that one rod is pulled up at the moment of switching, and the other is pressed. That is, at the moment of pulling up the first gear shift rod, the second gear shift rod is pressed. This made it possible to significantly reduce the shift time interval in comparison with a conventional gearbox.

Operation of the sequential gearbox

So, the familiar manual transmission has evolved and made it possible to come to a new type of transmission, which should simplify the driver's control of the car. And such an important invention was the automatic transmission, which was modernized and improved. And today, it gives the driver the opportunity not to think at all about what and when to switch gears. But no one threw aside the mechanical equipment either. It also continued to develop and now the result of these studies was a sequential gearbox. The result of such a transmission was the inclusion of speed in strict sequence.

Principle of operation

This type of gearbox was developed on the basis of mechanics. The main difference between this transmission is that instead of helical gears, gears with straight teeth are installed here, and there is also no clutch pedal (the electronic control unit took over this role). Gear shifting in the box is carried out using a hydraulic mechanism, which leads to a significant reduction in gear shifting.

Racing car with sequential gearbox

The installation of a gearbox with a sequential mechanism has found particular distribution in racing cars. Realizing that such a sequential gearbox would be especially convenient for racing drivers, it meant that it was necessary to carry out such an installation on racing cars. This is due to the fact that high speed contributes to strong vibration of the car and in this case it is difficult for the driver to get into the required gear, while the sequential gearbox is able to cope with this task.

Advantages and disadvantages

This sequential transmission has its own characteristics. The advantages of this unit include the absence of a clutch pedal, which is especially convenient for novice drivers. Following positive quality, which characterizes this model of the device - the speed of switching speeds, which exceeds the classic automatic and mechanical transmissions. Another advantage is the economy, which occurs due to the reduced gear shifting. It also offers the possibility of choosing a mode - mechanics or automatic.

The disadvantage of this device can be called its design. That is, this mechanism is not resistant to wear and quickly fails under heavy load. An example is racing cars. After each race, the sequential gearbox most often undergoes a mandatory bulkhead. In principle, if you do not follow the operating rules, then the sequential gearbox can fail on serial cars, which means it will entail expensive repairs.

How it works

We all know what an automatic or adaptive and manual box is. In the first case, the system does everything itself, based on the current loads and the speed of the machine. That is, it adapts to the car. In the case of mechanics, you need to change gears yourself.

In the case of a sequential gearbox, it is important to note that it is distinguished by the ability to switch gears sequentially. Roughly speaking, if on the mechanics you can “jump” from 5 to 3 speed, then the sequence will not allow you to do this. There is a switching sequence that the SKPP cannot violate.

Initially, SKPPs were created for racing cars, Formula 1 cars and cars that take part in professional races. But automakers liked the idea, which is why many are introducing such boxes into civilian cars. And it pleases.

The mistake of many is that they consider SKPP an analogue of automatic transmission. In fact, mechanics were the inspiration for the creation of the sequence. It was built on the basis of the manual transmission.

Consider the principle of operation of this device and the key features of the SCP. So you will understand what it is and how the whole sequential system works.

1. The transmission does not have a clutch pedal. It pleasantly pleases those who do not have much driving experience. Management is simplified, no need to constantly squeeze the clutch. The electronics is responsible for it, receiving signals from sensors when reading pressing the gas pedal and switching on the gear. The box, having received a command from the control unit, sends a signal with sensors about the speed at which the car is currently moving. The progressive block is the last stage where the movement parameters are adjusted. He studies literally everything, from engine speed to on or off air conditioning.
2. In the design of the sequencer, spur gears are used. Their efficiency is higher compared to helical structures standing on the mechanics. The latter have impressive friction losses. Although spurs transmit less torque. To compensate for this, gears are put in large sizes.
3. Servo hydraulic type. The last distinguishing feature. Such a device switches between speeds. Now many are sure that the hydraulic servo drive is a property robotic boxes. A common mistake, because they use electrical devices.

The sequencer works very simply. You can use the gearshift lever directly or the paddle shifters. This is a technology borrowed from racing cars that has taken root very well among the people. Especially in BMW and Toyota.

If you look at the box, you will see a lever on it that moves up and down. Plus there are additional modes, depending on the automaker.

Pressing up (where it stands +) raises one gear up, and moving to the side with a “minus” allows you to lower the box by 1 gear.

That's what it means to be comfortable and convenient. It is not surprising that many seek to put a manual transmission on their car. Some craftsmen manage to shove a box onto the VAZ 2108 and 2107. There are also factory models that are paired with a sequential one.

But I'll be honest. This is true for sports cars, from which you expect speed and minimal losses during acceleration. For a car with less than 150-200 under the hood Horse power, and which serve for family trips, there is no need for SKPP.

Principle and device

The easiest way is to compare a sequential box with mechanics. Moreover, they have almost the same base. The main difference is in the gears. Here, instead of oblique teeth, there are straight ones. In the design itself, there is no cohesion as superfluous.

Attention! The control unit is responsible for shifting gears.

The switching itself takes place hydraulically. Thanks to all these features, the sequential gearbox is often installed on racing cars. The common denominator of all these upgrades was that the gearbox ceased to depend on vibrations. More precisely, the rider does not need to spend time looking for the right gear.

When comparing a conventional gearbox and a sequential gearbox, special attention must be paid to the moment of shifting thrust. As soon as this happens, the actuator rod is pulled up, rotated and pressed. This happens in the standard system, but not in the serial system.

It is interesting: Fuel filter Mazda 3

In a sequential box, when switching, one rod is pulled up, and the other is responsible for pressing. This reduces the time interval. This technical innovation has allowed us to reach a new level of performance.

What is a sequential gearbox:

Features of functioning

The shift lever in cars that have a sequential gearbox is located on the steering wheel. In some modifications, you can see the buttons. The system operates in the following modes:

• sports;
• standard;
• automatic.

The first two options use mechanics. It is not surprising that many novice drivers prefer to drive with just such a gearbox. As soon as they reach the required level of driving skill, the full range of system capabilities will open up for them.

Sequential gearbox

car sequential gearbox

The difference between a sequential gearbox and a standard mechanical gearbox is that such gearboxes are only two-shaft, all the gears in them are only spur gears and there are no synchronizers. Their role is performed by movable couplings, which include gears. In addition to design differences, there are also operational ones: in a manual gearbox, the gear is engaged after the clutch is released (experienced drivers change gears by selecting the necessary speed and without clutch), and in a sequential box, when driving in a straight line or uphill, gears can be changed without disengaging the clutch, which allows do their design. Also, the advantages of sequential checkpoint include:

• smaller dimensions box body;
• the ability to transmit more torque;
• withstands variable loads;
• switching speed is 0.1-0.2 sec;
• when changing gears, the engine speed does not fall;
• power is not lost in the transmission, which is caused by the heating of parts;
• ease of maintenance.

In a sequential gearbox, when driving in a straight line or uphill, gears can be changed without disengaging the clutch.

It is worth noting that the principle of operation of a sequential gearbox is based only on sequential gear changes in both reverse and forward order. Thus, the gear increase is carried out in steps, i.e. you cannot jump, for example, from the second to the fourth, because the design of the box will prevent this.

Also, one of the features of the device of a sequential gearbox is that the primary and secondary shafts in such a transmission are type-setting, i.e. consists of several intermediate interconnected elements. This feature allows mechanics to quickly change gears on sports cars right during the race in order to find the optimal gear ratios for gears under current competition conditions.

Pros and cons

Now you know what SCP is and what sequentiality means. Not? Yes, this is the sequence in translation. This is where everything falls into place.

After watching the video and studying the features of such a box, the question arises - is it worth taking a car from this checkpoint. I will help you a little by telling you about the strengths and weak sides sequentalok.

Let's start with the benefits.

• High switching speed. The machine lives its own life, so sometimes it frankly blunts and does not do what you expect. The mechanics are harder to switch. The optimal speed is given by the SKPP. The electronic block and hydraulics provide the minimum expenses on time for transition from transfer to transfer. For professional motorsport, this is extremely important.
• Convenience. Depressing the clutch pedal, getting into gear, and even at speed on a bad road, is a dubious pleasure. SKPP guarantees accuracy and comfort when switching. This is an indisputable fact.

• No loss of speed. Yes, the sequential gearbox shifts quickly, there are no gaps between transitions, hence the measured ride, a quick set of speeds.
• Fuel consumption. All the previous points affect the appearance of this advantage. SKPP carefully consumes fuel and helps to save.
• Paddle petals. An additional option that allows you to feel like a racer. Comfortable and unusual.
• Two modes. But I'll make a correction here. This automatic transmission has the function of switching to manual mode using a sequential system. So it's rather a plus of machines.

But not everything is so perfect. SCPP has two significant drawbacks.

• Low resistance to loads and wear. The system is complex, consists of many elements and requires careful handling. You can’t just randomly click the petals or the lever. It is necessary to choose the right moment for switching. If this is not done, the mechanisms will quickly fail. It is not in vain that SKPPs are installed on the cars of professional racers.
• Price. It is high on the car itself with a manual transmission and on the maintenance of such a box. Although if you have the money for a sequential car, the cost of repairing it shouldn't be a problem.

Historical information about the sequential box

The sequential box is often used by BMW designers in their cars. The first implementation took place in 1996. Then the E36 M3 model acquired a similar system.

Attention! The modification of the sequential box was called SMG 1.

For five years, drivers have been able to appreciate all the advantages of the sequential box. As a result, in 2001, the lineup was replenished with the SMG 2 system. E46 M3 cars are equipped with it.

The E46 M3 concept was a real hit. Moreover, the reviews of motorists were more than positive about him. Finally, in 2005, SMG 3 appears. In it, the time required for switching has become even less.

Such a tricky and difficult to pronounce word for a simple Russian person, like sequential, is derived from the English sequence, which means: sequence. And the English name sequential manual gearbox in Russian sounds like a sequential gearbox. This is a device on cars of a certain class, allowing only sequential gear shifts from first to high and vice versa, without jumping.

traditional box

On traditional gearboxes installed on most domestic cars, the neutral position of the gearshift lever is set in the middle. In order to move off, we depress the clutch and shift into first gear. In the future, with a set of speeds, their sequential switching is recommended.

However, nothing prevents us from starting immediately at the second speed, if the road condition is normal and the engine is designed for such an action. Trying to start the engine with a dead battery, we, pushing the car, can immediately turn on the third, and even the fourth, to make it easier. Nothing prevents this. Decreasing the speed to perform a maneuver, we, having slowed down, from the fourth gear go immediately to the second or to the first. Having mixed up, you can turn on the wrong speed on the go, which is far from harmless for a car.

Automatic transmission

To simplify driving, an automatic transmission was invented, which freed the driver from the need to select a driving mode on a particular section of the road. The machine itself switches, while the driver, working with one foot, either increases speed or slows down. Driving a car with automatic transmission requires less skill, and it is not for nothing that the permit to operate such a vehicle is now highlighted in a separate category.


But work on improving the mechanical transmission did not stop. As a result, a sequential transmission appeared, which also does not provide for the presence of a clutch pedal, but works on different principles. And its main feature is strictly sequential switching of speeds.

Sequential principle

Sequential gear changes can be noted, for example, on motorcycles, where they are switched on by foot. The neutral position there is most often located between first and second gear. The same mechanics are used on tractors, on big trucks. Sequential connection is most widely used in boxes sports cars, where every millisecond is precious and speed reduction when switching is unacceptable. The use of hydraulics allows you to further accelerate this process and reduce it to a minimum.

The sequential mechanism is based on a conventional manual gearbox, somewhat complicated in the process of modernization. The main feature is that with its help it is possible to switch from a lower to an increased gear without reducing the speed of the car, which invariably occurs when a traditional gearbox is operating.

Cam or sequential

It must be said that a cam gearbox is installed on a number of racing cars. Although if the cam transmission is also made sequential, the already very high speed of switching modes will be even higher. And this is already applied on Formula 1 cars.

Unlike the helical gears on a traditional car gearbox, the cam gears are spur gears and long. This makes it related to the transmission of a sequential box. And it is this feature that allows both systems to switch without slowing down. At the same time, the device of the box itself is simpler - there are no synchronizers, but instead of many small teeth on the gear and clutch, there are end projections. Those same cams that directly engage with the gap.

Peculiarities

On cars with a sequential gearbox, the shift lever is located on the steering wheel. Alternatively, buttons can be installed on the steering wheel. The desired button is marked with the letter "S". Both automatic and manual switching is provided. In this case, the box can operate in three modes:

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

The advantages of this car of the future are the following points:

1. A car with a sequential gearbox, like with an automatic transmission, does not have a clutch pedal - this is good for novice drivers.
2. This box provides a choice between automatic and manual switching.
3. High gearshift speed, which is reflected in the efficiency of the engine.

The disadvantage so far is the low wear resistance of the box mechanism.

As the situation on automotive forums shows, many motorists are very interested in the question of what a sequential gearbox is. We will immediately answer that this is often a manual transmission (although automatic options are increasingly common today), the main feature of which is the ability to shift gears only with strict sequence up or down. Thanks to this, the driver does not have to think about which gear to activate - he simply raises or lowers it. But this type of gearbox also has other features, so below we will take a closer look at what a sequential gearbox means.

We understand what a sequential gearbox is and what are its features

So, the main feature of the sequential gearbox is the lack of the possibility of a free choice of gears and jumping over several at once. The need for such a gearbox arose due to the fact that the driver does not always have time to select the desired gear and brake to shift it. By the way, such advanced manual transmissions are used not only in cars, but also in motor vehicles, where switching between gears is often carried out by foot.

If we are talking about sequential boxes installed on cars, then here they will be distinguished by the location of the control center. The lever (and sometimes even more convenient and responsive buttons) is located on the steering wheel of the vehicle for convenience, while it will be necessarily marked with a special “S” marking, which indicates the presence of a sequential gearbox on the car.

Important!On some cars with a sequential gearbox, shifting between gears can be carried out not only manually, but also automatically.

Such a gearbox has three main operating modes that can be activated in parallel with the main gears:

Standard mechanical.

Mechanical sports.

Auto when the driver does not need to shift gears at all.

The last feature of a sequential gearbox is that when it is installed on a car, there is no need to install a clutch pedal. This not only makes driving easier, but also allows you to operate the engine in standard conditions, regardless of driving style and experience of the driver.

Where are sequential automatic transmissions used?

Sequential automatic transmissions today can be found mainly on racing cars, as they are quite expensive, and in their intended use are fully adapted to these types of cars. Thanks to this gearbox, the driver gets the opportunity to increase speed and switch from gear to gear without the slightest slowdown, which is especially important for competitions. If, in addition, such a box will work on the basis of hydraulics, this will further increase the responsiveness of the car.

As for ordinary passenger cars, the sequential gearboxes installed on them are popularly referred to as the “manual” mode of operation of an automatic transmission. However, even in this embodiment, driving is considered lightweight and does not require the driver to accurately hit a specific gear. Among the production cars on which such boxes were installed, it is worth mentioning:

BMW M3.

Mercedes Benz C Class.

But in fact, sequential checkpoint is more common than it might seem at first glance. As mentioned above, such boxes are installed on motorcycles, where there are usually only two gears. As for the neutral position of the gearbox, on motorcycles it is usually fixed between the first and second gears. The sequential gearbox received even more distribution in the design and creation of agricultural tractors, on which the button or gearshift lever can be located both under the driver's feet and on the steering wheel. Sequential gearboxes are also found on heavy vehicles.

The device and principle of operation of a sequential gearbox

The basis of such a gearbox is the familiar mechanical transmission, which has been improved and equipped with spur gears instead of helical gears. A significant design difference of the sequential gearbox is the absence of a clutch pedal, which is compensated by the installation of an electronic control unit (it is also responsible for gear shifting in the automatic mode of the gearbox).

Shifting gears thanks to the hydraulic mechanism is as fast as possible and does not require precision, as in conventional gearboxes. All that is required from the driver while driving a car with such a box is an assessment of the complexity of the road and the load that is transmitted to the car engine. To make it easier for him to work, it is worth gradually increasing gears. If low speed maneuvering is required, the gears are downshifted based on vehicle behavior and engine response.

Sequential or cam gearboxes?

It is also worth mentioning the existence of cam gearboxes, which, in their design features, have much in common with sequential ones. In particular, they are united by the presence of spur and long gears with end projections (for which the cams cling), thanks to which such gearboxes allow you to switch from one gear to another as quickly as possible without reducing the speed of movement.

However, it is almost impossible to determine which gearbox is better. For this reason, the designers simply combined them into one mechanism, which is already used today on racing cars that take part in Formula 1. So it is more correct to call a cam gearbox a good alternative to a sequential gearbox.

The advantages of using such a box on cars and other modes of transport

We have already figured out what a sequential checkpoint is. However, let's summarize all the advantages of using such a gearbox in different modes of transport:

1. No clutch pedal. This feature is most relevant for those who are just learning to drive and can confuse the pedals. In addition, the lack of clutch makes it easier to control the car in difficult racing conditions, when it is important for the driver to concentrate not on the force on the pedal, but on the track.

2. Transfers are switched as quickly as possible. In this, no other type of gearboxes can compare with sequential gearboxes. This advantage should also include the fact that when you press the gear lever up or down, the driver does not have to think about which gear to shift the lever into. He just raises or lowers them.

3. Automotive designers also note that the lack of deceleration during the transition from one gear to another also has a positive effect on fuel economy.

4. Work on two modes - automatics and mechanics. Despite the fact that the designers have already simplified the process of driving a car with a mechanical sequential gearbox by transferring the buttons to the steering wheel, in some situations the driver may refuse to control the transmission altogether and entrust this task exclusively to the electronic control unit.

Disadvantages of sequential gearbox

The sequential gearbox is not without a number of disadvantages, and they are mainly associated with the design of such a gearbox. The first thing to think about when buying a car with such a gearbox is accelerated transmission wear. Do not forget that in extreme and too harsh operating conditions, the hydraulic mechanism wears out quickly and can fail at a very inopportune moment. For this reason, racing cars have to be completely sorted out and parts changed literally after each race.

It was also mentioned above that thanks to the installation of sequential gearboxes on serial cars, their power is significantly increased. But there is also a pitfall here: this can be achieved only if it is correct and timely to switch from lower to higher gears and vice versa. If the driver feels bad about his car and his needs, this again can lead to failure of all elements of the hydraulic transmission. At the same time, the restoration of such a system will cost the car owner very expensive.

In this regard, driving a car with a sequential gearbox is recommended only for experienced drivers who have driven their own both on a manual gearbox and on an automatic one. Lack of experience in driving a car can adversely affect its condition.

Based on the foregoing, it is quite difficult to determine the rationality of buying a car or installing a sequential gearbox on it. Although in general it provides a number of advantages, not all drivers have a need for it. And it’s not so easy to change lanes from the usual gearbox with a lever to the right of the driver’s seat.

As we know, the evolution of "boxes" in cars led the world to the invention of an automatic transmission, but the engineering mind did not stand still, and the mechanical transmission was not "put away in the closet" either - engineers modernized the gear shift mechanism and created a variant of the sequential gearbox. In it, the gears were switched only sequentially up or down.

Sequence - sequence

The principle of operation of this gearbox is simple as in conventional mechanics, but it differs from the usual transmission we are used to, with spur gears that are installed instead of helical gears, and the role of the clutch pedal is performed by a hydraulic mechanism. This mechanism allows you to reduce the time of gear changes, which is so important in motorsport. In addition to shifting speed, such a gearbox allows you to clearly shift gears at a time when the car is subject to vibrations and the use of a familiar gearbox is difficult. Also, one of the features of the device of a sequential gearbox is that the primary and secondary shafts in such a transmission are type-setting, that is, it consists of several intermediate interconnected elements. This feature allows mechanics to quickly change gears on sports cars right during the race in order to find the optimal gear ratios for gears under current competition conditions. However, not only sports cars can boast of such a "box" - and on your "automatic" you can move the selector position to the side and get a sequential gearbox. You usually call it "manual" mode.

Such a transmission has 3 possible options for working in a car:

• conventional mechanical
• mechanical sports
• fully automatic

And the selector lever can be located on the steering wheel, in the form of a button with a special marking.

And how to live with it?

As we know, any gearbox can cause a lot of controversy, have allies and opponents. This did not bypass the sequential transmission. But let's go in order: if you decide on a car with such a transmission, you will be pleased with the lack of a clutch pedal and the speed of the “box”, in addition, like any “mechanics”, a sequential transmission will save you fuel compared to automatic transmission. The second undoubted plus is the ability to drive in several modes, which we described above. Complementing our range of pluses is shifting gears directly on the steering wheel, in the presence of petals.

However, as we all understand, there are no perfect mechanisms, so even such a seemingly perfect box has problems. Since there is no clutch, as such, the hydraulic switching mechanism suffers, because it wears out more than usual due to increased loads. Look at the competitions in motorsport, for example in drifting, where after almost a couple of races the mechanics are already ready to repair the gearbox. Stock cars, of course, let you enjoy the ride a little longer, because if you do not play sports driver on the road, your gearbox will live happily ever after, but if you decide to play race car, get ready for the fact that repairing such gearboxes is very and very expensive, and replacing with a new one is even more expensive.

Myths and legends

It seems that they tried to figure out the technical and financial parts, and now let's go through the stereotypes associated with such boxes:

• "Sequential is a robot." But no! Although the principles of operation of such transmissions are similar, however, the robotic transmission has electric servos, against hydraulic ones in sequential ones.
• "Sequential and automatic are inseparable."- again not guessed. If not for the widespread sports modes on modern automatic transmissions, you would never know about a sequential box. Therefore, in civilian versions, a mixture of options is possible, but I have not seen sports cars with automatic transmission.
• "Only for sports cars, only for cars, only with a cam gearbox."- no, of course, if you use them in pairs, your advantage will be cosmic, but on production cars such transmissions have been excellent for more than one decade.

Not scared away?

If the enumeration of all the pros and cons did not scare away the desire to take possession of this type of transmission, I can only say one thing. This is the most promising type of “mechanics” that is relevant for powerful cars, and if we also deal with such a box, refine it and improve it, we will be able to return to that ideal world in which cars with a mechanical transmission have a place in everyday use, and in most models from manufacturers.

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