Automotive engineering has come a long way since its inception. Innovative developments in the field of transmission are direct proof of this. On cars that exist today, you can find various types of checkpoints. An example of such a mechanism is a sequential gearbox.

What is a sequential gearbox

Wide use new technology in the field of transmission received in the 1990s. Such a gearbox is a gearbox that allows you to switch gears only in a sequential way. It differs from the usual version known to all by the mechanism of operation. Sequential switching was provided for those cases when the action on the control system is carried out with the help of the foot, as, for example, on motorcycles. The sequential box is also relevant in cases with sports cars when fast gear changes are required. Application was also found in the case of a vehicle with a large number of gears. In this scenario, the traditional movement causes inconvenience. This is typical for trucks and tractors.

Often such boxes have a mechanical type of work. But with the passage of time and the development of technology, an automatic sequential gearbox is increasingly common. The difference from the usual option is that there is an opportunity to choose between manual and automatic gear shifting. Whatever type of work is used, main feature– strict sequence in switching. Only down or up. The driver either speeds up or slows down. This approach in the system of operation of the mechanism facilitates the process of driving for the driver and increases the speed of transition from one speed to another. It is for this reason that the automatic adaptive sequential system has gained popularity among many car enthusiasts. Simplicity and convenience are two main components that complement each other.

How a sequential gearbox works

The basis for the sequential gearbox is the same familiar mechanical transmission. Only in this case, it has been improved: the design uses straight gear teeth, instead of the common helical ones. It is also based on a servo drive based on a hydraulic system. It is thanks to this that the speeds switch quickly. A box of this type can be schematically depicted as follows:

Attention! sequential box gears does not allow the driver to select gears independently, that is, to jump from one gear to another through several at once.

Some motorists have a separate question about the sequential automatic transmission, namely, what it is. The answer lies on the surface: it is an automatic transmission equipped only with sequential gear shifting (i.e. sequential). A significant difference of this type is the lack of a clutch pedal in the car and the way the speed is switched (only down and up).

Dealing with the issue of the device of these structures, it is worth mentioning the cam sequential gearbox. In terms of design, both options have similar characteristics. For example, in both options there are both spur and long gears. They affect the speed of shifting from one gear to another. It is very difficult to determine which of these checkpoints is better. Therefore, experts in this field have combined these two mechanisms into one.

The principle of operation of a sequential gearbox

As mentioned earlier, the sequential gearbox is characterized by the absence of a third pedal - the clutch. This feature is especially relevant for those drivers who have little experience in handling vehicles on the road. After all, the constant distraction of the left foot on the clutch pedal is a problem for many. But this does not mean that this mechanism not in the gearbox. It is, it just works differently. Therefore, the operation of the sequential gearbox itself is different. The clutch is controlled by a special electronic unit, which, in turn, receives the necessary signals from the sensors. They determine the force of pressure on the gas pedal from the driver's side and control the inclusion of a specific speed. The gearbox receives a signal from the electronic unit, and that, in turn, with the help of sensors, transmits all the necessary information about the speed used to the progressive unit. This is where the last process takes place - adjustment speed limit based on the following indicators:

• number of engine revolutions;
• air conditioner operation;
• the force of pressing the pedal, as well as a number of others.

The next principle of operation of sequential gear shifting is the spur gears used. When compared with helical gears used in manual transmissions, they give a higher coefficient useful action. This is due to the fact that the first of them leave large losses during friction.

And the third feature of the operation of the sequential gearbox device is characterized by the presence of a hydraulic servo drive. Thanks to him, there is a quick switch from one gear to another.

Important! Hydraulic servo drives and robotic checkpoints- it's not the same thing. The differences lie in the design of the device: the latter uses an electric servo.

More detailed and visual information on how the sequential gearbox works can be obtained from the following video:

Which cars have a sequential gearbox

The most common sequential gearbox received for sports cars participating in races. For example, such a system of work is used in Formula 1 cars. Among the models of transport on which this type of checkpoint is initially used, the following stand out:

• BMW M3;
• BMW M5;
• mercedes benz C class.

But the sequential box is much more common than it seems at first glance. As mentioned earlier, you can meet a device of this type on agricultural vehicles and heavy vehicles. In the design of machines with a sequential gearbox, in this case it has become even more widespread.

Every driver wants to provide his car with everything necessary for a comfortable and safe ride. So some motorists install sequential gearboxes on their cars, specifically replacing the old transmission with a new one. Therefore, you can meet the device in completely different vehicles. Very often, a sequential gearbox is installed on a VAZ. This provides the driver with an easier driving experience. In this case, preference is given to the cam system. Thus, you can install this transmission on any car, the main thing is to choose the right model that is suitable in all respects. There are a large number of options for a sequential gearbox on a VAZ. Therefore, there will be no problems in choosing or finding the right device. Moreover, some offer individual assembly for the car by high-level specialists.

Pros and cons of sequential transmission

In order to figure out what to expect from the transmission, you need to consider its positive and negative sides. Among the advantages, the following points should be noted:

• High speed and convenience in terms of gear shifting. Thanks to the electronic unit and the hydraulic mechanism, the speed of transition from one speed to another is minimized. No other gearbox can boast of such indicators: neither mechanical nor automatic. Well, the main thing is that with the use of a sequential transmission, the driver will not have to frantically try to find the right gear at the moment. This is especially true when passing sharp turns or driving around the ring, when it is difficult to keep the car on the correct path.
• There is no loss of speed when switching. This feature has become a favorite among riders, and, of course, ordinary drivers also highly appreciated the presence of such a possibility in the transmission.
• Thanks to the well-designed sequential gearbox, fuel is consumed economically.
• Gear shifting with steering wheel paddles. This technology further simplifies driving while driving.
• Possibility to choose between automatic and manual shifting modes. Of course, sequential transmission can exist separately from this function. But if it is still used, then this definitely refers to the pluses.
• The clutch pedal is missing. This is especially true for novice drivers, who, due to their lack of experience, find it difficult to cope with manual transmission.
• When shifting the lever, you do not have to think about which gear to choose. The driver simply either lowers or increases the speed.

Cons of sequential transmission:

• Sensitivity to high loads and wear. It is not only about sports cars, but also simple civilian vehicles.

  Attention! No matter how easy it is to switch gears at a checkpoint, it is important to do it in a timely manner. If you neglect this item, the system will quickly become unusable.

• High maintenance cost. The principle of operation of the sequential box is a complex mechanism. The more complex the mechanism, the more expensive its maintenance.
• It is possible to achieve an increase in the power of the machine by installing a sequential box only if you switch from higher gears to lower gears and vice versa in time. So the driver must feel good about his car, which is not always an easy task.

Conclusion

The sequential gearbox has given motorists new opportunities. The device and the principle of operation deserve attention from drivers, and the convenience of use is gaining an increasing number of consumers. Thanks to all of the above, this type of checkpoint is becoming more widespread every year. And, given all the positive aspects of the gearbox, it's not easy.

Such a tricky and hard-to-pronounce word for a simple Russian person, like sequential, is derived from the English sequence, which in translation means: sequence. AND 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

At traditional checkpoints 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 improvement 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. The greatest distribution series connection received in the boxes of 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 often this mechanical box(although today automatic options are also increasingly common), 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 desired gear and slow down to switch 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 done with the 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 independent 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 on different types transport:

1. No clutch pedal. This feature 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 even refuse to control the transmission 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 you have to completely sort out and change parts literally after every 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.

Translated from in 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 self-selection transmission.

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

Such a 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, resulting in 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 switching time interval in comparison with regular box gears.

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 also mechanical equipment nobody pushed aside. 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 (this role was taken over by the electronic unit management). 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 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 such a 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 even on serial cars, the sequential gearbox can fail, 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 great experience driving. 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. Last distinguishing feature. Such a device switches between speeds. Now many are sure that the hydraulic servo drive is the property of 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, it is necessary Special attention give the moment of switching 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 transmission, the gear is engaged after the clutch is disengaged ( experienced drivers shift gears by selecting the required 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 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 weaknesses 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. Electronic unit and hydraulics provide minimum costs time to switch from transmission to transmission. 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. Additional option, allowing 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.

The gearbox of a car is one of the most progressive parts of a vehicle.

During the production of cars, fundamentally new gearshift systems with different mechanisms were developed. One such device is the sequential gearbox.

Sequential gearbox: what is it

The concept of "sequential" comes from the English word sequence which means "sequence". Gears in such a box are switched sequentially, from lower to higher, and vice versa. This switching principle is used in motorcycles where the control is by foot. Indeed, by controlling the gear shift with the foot, it is difficult to perform complex manipulations. Therefore, we chose a simple algorithm: moving the lever up corresponds to an upshift, down to a downshift.

Video - clearly shows how quickly the gearshift occurs on a sequential gearbox:

There are some more vehicles, where sequential checkpoints are traditionally used, military equipment (self-propelled artillery vehicles, tanks). They have their own specificity. First, they are driven by unskilled drivers. Secondly, a quick upshift is carried out with minimal “dips” in power during the shift. The second quality (practical absence of dips in power and speed) determines the use of sequential transmission in high-speed sports cars.

Video - what does a sequential gearbox mean on a racing Peugeot car 208:

The principle of operation of a sequential gearbox

The design of a sequential gearbox in appearance differs little from a traditional manual gearbox.

If you take a closer look at the gear mechanism, you can immediately notice that the teeth are located strictly perpendicular to the side surface of the gear.

This is necessary to ensure that they move in a straight line during switching.

On the one hand, spur gears have less friction than oblique gears due to the full correspondence of the surfaces. On the other hand, helical gears in a mechanical box are designed to increase the torque that the gear train can withstand. Therefore, gears of increased width are installed in many sequential boxes. This enhances the design of the teeth and their strength.

The design of the sequential gearbox makes it quite easy to organize automatic switching modes. There are the following sequential gearboxes:

• with the usual mechanical system gear shifting;
• with sports switching system;
• with automated switching system.

Hydraulics are used to increase the switching speed. With the help of hydraulic servomotors, the switching time is minimal. During the activation of the shift to another gear, the accumulator is filled, which helps to create pressure in the hydraulic system. The shift time is a tenth of a second. This decisive fact determines the use of sequential gearboxes in sports cars. Often the gearbox controls are placed in the steering column area, which further simplifies the control of the modes.

How is it different from robotic

Many motorists mistakenly believe that the sequential gearbox is a close relative of the robotic one. Their fundamental difference consists in application in a sequential box hydraulic system when shifting gears. The robotic box uses an electric drive for this. also in robotic boxes a different gear shift mode is applied.

Video - shifting gears on a sequential gearbox of a racing car:

Their advantages and disadvantages

The main advantages of such boxes:

• minimum time for switching speed;
• minimal power losses of spur gears;
• fuel economy;
• the ability to switch from manual to automatic mode;
• the ability to control switching from the steering column;
• application of the system without using the clutch pedal.

Disadvantages of sequential gearbox:

• sequential gear shifting sometimes hampers the driver in terms of extreme driving styles, necessary gear shifts, for example, during engine start “from the pusher”;
• relatively high weight of the gearbox with a similar power;
• reduced service life associated with the technical complexity of the mechanisms;
• high maintenance and repair costs.

In which cars can you find a sequential gearbox

Of the most common cars you can give an example of a 1996 BMW with an SMG box. The SMG1 and SMG2 systems were installed on the BMW third series with the S index. Since 2004, this transmission has been installed on the BMW E60 M5. Also, a sequential gearbox was installed on certain models of Toyota Corolla, Mercedes S-class, BMW X5.

The layout of the sequential gearbox and its elements is shown in the figure:

In the figure: 1 - sequential gearbox control unit, 4 and 5 - indicator and mode switch, 7 - 6 step gearbox, 12 - hydraulic block, 10 - hydraulic drive, 11 - clutch.

Features of installing a sequential gearbox on VAZ cars

Many motorists, as an upgrade to their VAZ, purchase sequential gearboxes with a cam mechanism. Their appearance approximately like this.

As for a significant effect, one cannot count on this, since the dynamics of the car, judging by the reviews of the owners, increases slightly, although these boxes are called "sports". In addition, the weight of such boxes is usually higher than traditional ones. Wide massive gears with a perpendicular arrangement of teeth are used there to compensate for their low load capacity.

In addition, spur teeth increase the noise level of the gearbox. The real service life of a handicraft sequential gearbox is short. Such a gearbox can be installed if the car is supposed to participate in sports competitions, but not for everyday city driving.

conclusions

Summing up, it can be noted that the development and introduction of sequential gearboxes into mass production has made a certain technical progress in the development of the automotive industry. Such checkpoints have not received wide distribution due to the presence of numerous shortcomings.

Read about and what it does.

Thickness gauges paintwork car body and have different working principles.

The evolution of the manual transmission led to the invention of a number of types of transmissions, which in one way or another simplified the driver's control of the car. An important step in this regard was the invention of an automatic transmission, which was subsequently transformed and improved, allowing the driver not to think at all about when and how to switch to the desired gear. But the mechanical transmission did not go unnoticed by engineers - it was also constantly modernized and modified, inventing more and more new gearshift mechanisms. One of the results of such research was a sequential gearbox - a transmission characterized in that its gears can only be included in a strict sequence: up for upshifting, down for downshifting.

The principle of operation of a sequential transmission

This type of gearbox is built on the basis of a conventional mechanical transmission. Its main difference is that instead of helical gears there are spur gears, there is no clutch pedal (this role is performed by the electronic control unit), and the gears in this box are switched using a hydraulic mechanism. This significantly (up to 150 milliseconds) reduces the shift speed, which is most important for sports cars, on which, by the way, sequential gearboxes are installed most often. So, it is a gearbox with a sequential mechanism that is mounted on racing cars participating in Formula 1 and other similar competitions. The designers realized that a gearbox with such a mechanism would be the most convenient for the rider, because when driving on high speed when the car is subject to vibration, it is quite difficult to get into the right gear. And the sequential gearbox copes with this task by five plus.

However, for more than a dozen years, the sequential gear shift mechanism has been used on “civilian” cars. In everyday life, it is called the "manual" mode and it is typical for automatic transmissions.

Pros and cons of a sequential gearbox

Like any mechanism that works under load, the sequential transmission has its own characteristics. TO positive aspects This unit includes the absence of a clutch pedal, which is important for novice drivers (if we are talking about using this type of transmission on production cars). The second positive factor in the selective gearbox is the gearshift speed, which is higher than that of the classic ones. The third advantage of this gearbox is economy - thanks to the reduced shift times. The fourth aspect is the choice of two gear shift modes (automatic or mechanical). Such a box is characterized by the presence of paddles on the steering wheel, through which the driver shifts gears without taking his hands off the steering wheel.

This box also has its drawbacks, and they lie in the design of the unit itself. The fact is that the hydraulic mechanism of the sequential gearbox is unstable to wear and, when driving under heavy load, is prone to frequent failure. On sports cars, where loads are very high, such a box is often sorted out after every second race. For sequential boxes used on production vehicles (BMW M3, M5, Mercedes-Benz C-Class) is characterized by a higher power resource due to the fact that they do not experience overloads, like racing cars. And yet, if you operate the sequential box incorrectly (in manual mode, it is important to feel the moment and shift gears in time), then it will not last long on a production car - it may fail hydraulic drive clutches and other components and assemblies of this transmission. And repairing a sequential gearbox is not a cheap pleasure.