The device and malfunctions of a manual transmission. How it works

A manual gearbox is a device for stepwise change in the gear ratio of the rotational speed from the engine to the drive wheels. When using a manual transmission, the driver selects and engages the desired gear manually (as opposed to an automatic transmission). The name of this device also reflects the fact that all of its functionality is implemented only through mechanical elements, without involving hydraulics or electronics (unlike hydraulic or electric transmissions). Popular, but technically reliable, the principle of operation of the manual transmission is covered in this publication.

Why did automakers need to introduce a gearbox? Because any internal combustion engine of any car is able to operate only in some limited, and rather small, speed range. And the frequency of rotation of the wheels - from starting off to driving at high speeds - occurs in a much wider range. And it is not possible to choose any one universal gear ratio that would provide this entire range, while making reasonable use of the engine speed range.

For starting off and progressive acceleration of the car, as well as when driving off-road, it is required to expend more work in the physical sense, that is, to apply more power to its wheels. That is, at low speeds, high engine speeds are needed.

On the contrary, with a uniform movement of an accelerated car on a flat road, its speed is high, and high power and high engine speeds are no longer required - to maintain the desired speed, both low power and low speeds are sufficient. With an increase in speed, the aerodynamic resistance to the movement of the engine also increases, which requires high revolutions and more significant power consumption. The same thing - when driving uphill, you need to increase the traction force.

Hence the need arises to transfer rotation from the engine to the wheels with a certain gear ratio, which could be changed depending on driving conditions. One of the pioneers of the global automotive industry, the German engineer Karl Benz, was convinced of this in the very first long (80 km) trip in a car of his own design.

This road trip took place in 1887. Karl Benz and his wife Bertha and their sons were visiting the inventor's mother-in-law. The 80-kilometer journey proved to be very difficult due to the imperfection of the design of the first car. On some, seemingly small, rises it had to be pushed manually: there was not enough traction. After this trip, Benz improved the car, providing it with an additional auxiliary gear - "lower", to increase traction.

This idea is used in the gearbox to this day: the gear ratio should be variable, allowing you to use different ratios between the speeds of rotation of the crankshaft of the motor and the drive wheels.

Of course, Karl Benz's first manual transmission was at first a very primitive device. These were pulleys of different diameters attached to the drive axle. They were connected to the motor by a belt, and with the help of levers, the belt could be thrown from one pulley to another. Subsequently, the leather belt and pulley were replaced by a metal chain and an asterisk, as on modern "advanced" bicycles.

A gear train and a gearbox on gears were first put on a car by Wilhelm Maybach. In parallel with the German auto engineers, around the same years, the French were also engaged in similar research. The mechanical gearbox created by Emile Levassor and Louis Panhard already used a whole set of gears with different gear ratios for moving forward and one gear for moving backward. As in our time, the gears of the forward gears were mounted on the secondary shaft, which moved along its axis. This allowed gears of different diameters to engage with a fixed gear on the input shaft.

Officially, Louis Renault became the inventor of a mechanical gearbox similar to the modern one: in 1899, this young novice auto industrialist patented the world's first gearbox based on a system of movable gears and shafts. It was three speed.

The first person to patent the manual transmission - Louis Renault - in his "laboratory".

The overseas pioneer of the automotive industry - Henry Ford - did not copy the achievements of German and French engineers, but went his own way. His manual gearbox consisted of several planetary gears (satellites), which rotated around the central (“sun”) gear and were fixed with the carrier. It was this planetary gearbox that was equipped with the first mass-produced Ford A cars.

No less important technical solution than the invention of a box on gears of various diameters was the invention of a synchronizer, which was made in 1928 by Charles Ketering from General Motors. It made manual transmissions easier to operate, gave them a new impetus for development and "technical longevity".

More than 120 years have passed since the invention of Louis Renault, but the main principle of the stepped gear gearbox has remained the same. Modern manual transmissions, of course, are much more perfect: they have gears not with direct, but with helical gearing, and they are more convenient, quieter and more durable. In general, cars with "mechanics" are more economical than cars with automatic transmission.

A manual gearbox consists of a set of helical gears of different sizes, which are engaged to create different gear ratios between the crankshaft of the motor and the drive wheels. The gear ratio becomes different by moving both the gears themselves and a special device - a synchronizer. Its task is to equalize (synchronize) the circumferential speeds of the gears included in the engagement.

The principle is that the higher the gear ratio, the lower the gear. The first gear is called the lowest gear, and its gear ratio is the largest. On it, the transmission of rotation is carried out from a small gear to a large one and, at a high crankshaft speed, the speed of the car remains low, and the traction force remains high. In the highest gear, respectively, the opposite is true. In the neutral position, the torque from the motor is not transmitted to the drive wheels, and the car rolls by inertia or stands still.

Most mass-produced modern cars equipped with a manual gearbox have 5 "speeds", or forward speeds. A few decades ago, most automotive manual transmissions were four-speed. Manual gearboxes with six or more speeds, as a rule, are equipped with “charged” sports cars or jeeps.

From a technical point of view, a manual gearbox is a closed stepped gearbox. The working elements of its design are gear wheels - gears that alternately engage, changing the speed of the input and output shafts, as well as their frequency. Switching connections and combinations of gears is done manually.

A manual gearbox can only function in tandem with the clutch. This assembly is designed to temporarily disconnect the motor and transmission. This operation is necessary for a painless and safe transition of gearing from one gear to another, without turning off the engine speed, and with their full preservation.

The layouts of mechanical gearboxes that have become widespread are two- and three-shaft. They are called so by the number of parallel shafts on which the helical gears are located.

In a three-shaft manual transmission there are three shafts: driving, intermediate and driven. The first is connected to the clutch, there are splines on its surface. The clutch disc moves along them. From this shaft, the rotational energy is transferred to an intermediate shaft rigidly connected to it by a gear.

The driven shaft is coaxial with the driving shaft, connected to it through a bearing, which is located inside the first shaft. Therefore, these axes are provided with independent rotation. Blocks of "different-sized" gears of the driven shaft do not have a rigid fixation with it, and are also delimited by special synchronizer couplings. Here they are rigidly fixed on the driven shaft, but can move along the shaft along the splines.

On the ends of the couplings, gear rims are applied, which can be connected to similar rims on the ends of the driven shaft gears. Modern gearbox production standards require the presence of such synchronizers in all forward gears.

In a two-shaft manual transmission, the drive shaft is also connected to the clutch unit. Unlike the three-axle design, the drive axle has a set of gears instead of just one. There is no intermediate shaft, and the driven shaft is parallel to the leading one. The gears of both shafts rotate freely and are always engaged.

On the driven shaft there is a rigidly fixed main gear drive gear. Between the remaining gears are synchronizing clutches. A similar scheme of a mechanical gearbox in terms of the operation of synchronizers is similar to a three-shaft arrangement. The difference is that there is no direct transmission, and each stage has only one pair of connected gears, and not two pairs.

At one end of the driven shaft, the main gear is in rigid engagement. A differential works in the main gear housing.

The two-shaft arrangement of a manual transmission has a higher efficiency than the three-shaft, but it has limitations in increasing the gear ratio. Due to this feature, the two-shaft manual transmission design is used exclusively in passenger cars.

In rare cases, four-shaft gearboxes may also be used on modern vehicles. But according to the principle of their work, they also correspond to two-shaft ones - without an intermediate shaft, with the transfer of rotation from the input shaft directly to the secondary ones. Most often, these are manual transmissions with 6 forward gears. In them, the torque is transmitted from the input shaft to the final drive through the first, second and third secondary shafts, the end gears of which are constantly engaged with the final drive gear.

Ensuring the reverse gear of the car is entrusted to an additional shaft with its own special gear. When it goes into engagement, the rotation of the driven shaft begins in the opposite direction. There is no synchronizer in reverse gear, since reverse gear is activated only when the car is completely stopped. In any case, this is how it should be done. Therefore, the manual transmission of cars from many manufacturers has protection against accidental reverse gear on the go (you need to lift a special ring on the lever to move it to the reverse position).

When the neutral mode is on, the gears rotate freely, and all synchronizer clutches are located in the open position. When the driver depresses the clutch and shifts the lever to one of the steps, a special fork in the gearbox moves the clutch into engagement with the corresponding pair at the end of the gear. And the gear is rigidly fixed with the shaft and does not scroll on it, but ensures the transmission of rotation and force energy.

While driving, the gearshift mechanism is actuated from the driver's seat using the gearshift lever. This lever moves the sliders with the forks, which in turn move the synchronizers and engage the desired speed.

Pairs of gears of the two lower gears have the largest gear ratios (on passenger cars - usually from 5:1 to 3.5:1), and are used for starting and progressive acceleration, as well as, if necessary, constant movement at low speed, or off-road. When driving in lower gears, even at high engine speeds, the car will drive quite slowly, but its power and torque will be fully used. On the contrary, the higher the gear, the higher the speed of the car at the same level of engine speed, and its traction force is less. In higher gears, the car will not be able to start or drive at low speeds. But it can move at high, up to the maximum provided, speeds, at medium engine speeds.

In the vast majority of modern manual transmissions, gears with an oblique tooth are located, which are able to withstand greater forces than spur gears, and besides, they are less noisy in operation. The helical gears are made from high alloy steel, and in the final stage of production, HDTV quenching and normalization for stress relief are carried out, ensuring the durability of the parts.

Prior to the advent of synchronizers, for bumpless upshifting, drivers had to double-squeeze, with the obligatory work for a few seconds in neutral, to equalize the circumferential speeds of the gears. And in order to switch to a lower gear, it was necessary to make a regassing in order to equalize the speed of the drive and driven shafts. After the introduction of synchronizers, the need for these manipulations disappeared. And the gears have become protected from shock loads and premature wear.

However, these “skills from the past” can also come in handy for a modern passenger car. For example, they will help to shift the same gear in the event of a clutch failure, or if there is a need for sudden engine braking when the working brake system has failed.

Every car enthusiast has seen or even driven a car with a manual transmission, because training in most driving schools, as a rule, takes place on the “mechanics”. But not everyone knows the history of the origin of this unit, the principle of its operation, advantages and disadvantages. That is what we will talk about in this article.

Autolady and manual transmission are incompatible concepts. Believe me, driving a car, painting lips, talking on the phone and shifting gears is really difficult.

To begin with, let's figure out what the decoding of the abbreviation for manual transmission is and what it generally means. Manual transmission stands for manual transmission and means that gear shifting is carried out mechanically, that is, manually.

If we try to give a brief description of a mechanical box, we can say that it is a block with many gears inside, which is closely adjacent to the engine and transfers its energy to the wheels. Interaction with the manual transmission occurs using the gear lever and clutch pedal.

We owe the appearance of a manual transmission to a woman. Yes, yes, you heard right and this woman was none other than the wife of Karl Benz Bertha Benz. It was she who, after completing her famous “tour” in a Motorwagen car, expressed her dissatisfaction with her husband about the fact that the engine thrust was not enough to overcome even a small hillock. This happened on August 5, 1888. Not daring to argue with a woman, Karl Benz in 1893 produced the Benz Velo car, on which a 2-speed planetary manual transmission transmitted torque from the engine to the wheels.

Bertha Benz is the wife of Karl Benz, Benz's first Motorwagen and the famous tour from Mannheim to Pforzheim and back, which Bertha Benz made in 1888.

Further, the manual transmission or MT (manual transmission) evolved only by increasing the number of gears and this process was quite fast. The first two-speed gearboxes with reverse gear were installed on the very first production cars of the Ford brand at the very beginning of the 20th century. Three-speed gearboxes were also not long in coming and appeared as early as 1910. They were used on European cars, and later on American ones. Three-speed manual transmissions were very common until the early 1960s.

Further, four-speed boxes come out, which, by the way, appeared a very long time ago, but due to the fact that the first samples were without synchronizers, they were not popular. When the 4-speed gearbox acquired synchronizers in the 1960s, then it gained its wide application. In the USA, “four-steps” were used only on sports cars for a long time, and in Europe they immediately began to be installed almost everywhere.

The first 5-speed gearbox also appeared in the 1960s, but it received mass use only 20 years later. In such boxes there were four main forward gears, and the fifth, overdrive, was built into the box itself. Prior to this, overdrive (aka “overdrive”) was a separate unit.

In the 1990s, six-speed manual transmissions appeared. They also had four main speeds, but they already had two boosters. After another 10 years, a 7-speed “box” appears, which has five basic and two overdrive gears.

Mechanical seven-speed gearboxes were installed in sports cars Porsche 911 and Chevrolet Corvette Stingray, in order to more efficiently use the torque of a powerful engine.

This is where the development of the manual transmission has ended so far - the design idea has gone into the development of automatic transmissions. At the moment, the descendants of the "mechanics" are robotic gearboxes. They have the same device and technical characteristics as the MT, but they switch gears and control the clutch on their own.

Device

A manual transmission is a set of shafts with gears. All these details are located in one case. "Mechanics" is three-shaft and two-shaft.

The first option is installed on cars with a classic layout - front-engine rear-wheel drive. These are our beloved “penny” and “six”. Such manual transmissions include primary, secondary and intermediate shafts.

Drawing of a mechanical gearbox, which shows that the design of the "mechanics" is quite simple - a set of gears, drive and driven shafts, shift clutches.

The input shaft (aka the drive one) connects the box to the engine flywheel through the clutch. The secondary (driven) is connected to the cardan shaft, and the intermediate one serves to transfer rotation from the input shaft to the secondary one.

On the input shaft is the drive gear, which drives the intermediate shaft, and on it, in turn, is its own gear set. They are rigidly connected to the shaft and, often, are one with it. On the secondary shaft is a set of driven gears that are in the splines of the shaft and move along them. They can also rotate in hubs.

Three-shaft manual transmissions have larger dimensions and weight than two-shaft ones, but direct transmission of torque from the input shaft directly to the output can be realized in them. Also, three-shaft manual transmissions have the ability to achieve large gear ratios and a wider power range than their two-shaft competitor.

Three-shaft "boxes" are currently installed on all cars with a classic layout, as well as on trucks and SUVs.

This simple diagram shows the main components of a three-shaft manual transmission.

Most modern front-wheel drive vehicles are equipped with two-shaft manual transmissions. In them, the torque is transmitted from the gears of the input shaft to the gears of the output shaft. The input shaft, like the three-shaft manual transmission, is connected to the engine, and the secondary transmits torque to the wheels. The shafts are parallel to each other.

Due to the lack of an intermediate shaft, such boxes are more compact and have less weight, but due to the large number of additional gears, the efficiency of this type of manual transmission is lower. The advantage of two-shaft manual transmissions lies in the possibility of combining the engine and transmission into a single power unit of a relatively small size. Such characteristics make it possible to use this type of manual transmission in cars with a rear engine and front wheel drive, as well as on heavy motorcycles.

The principle of gear shifting

In manual transmissions, gear shift clutches are located between the gears of the output shaft. Depending on the number of couplings, the boxes are divided into several types - two-way, three-way, four-way, and so on. For example, three-way manual transmissions have three clutches, each of which can block two gears on each shaft. It follows that a three-way manual transmission can have 4 or 5 forward gears. Four-way can already have 6, 7 or 8 gears. Go ahead.

On the gears of the output shaft there are toothed rims. They are connected to the rear ends of the drive shaft, and the mating rims are on the engagement clutches. When you switch gears by moving the gear lever, then due to a special drive through the sliders, the gear shift forks move, which move the above clutches. The manual transmission has a special locking mechanism that prevents the inclusion of several gears at once.

When the engagement clutch approaches the required gear, their rims are connected and the clutch blocks the transmission gear. Then they begin to rotate together, and thus the torque is directed to the wheels.

Animated shift diagram of a 4-speed gearbox. The first rod includes the first and second gears, the second rod - the third and fourth, and the third rod for the reverse gear.

In order to change gears without bumps and shocks, synchronizers are provided in the manual transmission. They equalize the speeds of rotation of the gear and the clutch and do not allow the clutch to do its work until the specified speeds are equal.

Management of "mechanics"

The classic way to shift gears in a manual transmission is by using a special lever. It is located directly on the lid of the box, or connected to it through an extension cord. It is he who acts on the gearshift forks, and you yourself control the lever itself.

With this control scheme, the speeds turn on most clearly. Also, this scheme has a long service life, but it also has disadvantages. The classic manual transmission control scheme is highly dependent on the layout of the car. In many cases, the lever can be moved forward or backward relative to the driver, creating uncomfortable conditions for shifting. In addition, due to the fact that the lever has direct contact with the box, vibration from the engine is transmitted to it.

The second manual transmission control scheme is when the lever is located at a distance from the box and is connected to it with the help of rods. This solution allows you to install the lever in a place convenient for the driver, regardless of the layout of the car. In addition, with this scheme, vibration is not transmitted to the lever. But these boxes have their own characteristics. Firstly, the rods become loose over time, as a result of which they need to be adjusted or even changed, and secondly, there is a reduced clarity of gear shifting.

The gear lever and clutch pedal are mandatory attributes for operating a manual transmission. If you can still somehow put up with the clutch pedal, then the shift lever makes it difficult to drive a car, especially for beginners and women.

The above two schemes are the main ones. But there are also others. For example, switching with pneumatic or electromechanical actuators. Such schemes are used mainly on trucks, buses and agricultural vehicles, so we will not consider them in detail. There is also a sequential control of the "mechanics". In it, the speeds are switched sequentially using a rocking lever, joystick or “petals”. Sequential shifting is mainly used on sports cars and motorcycles. On such manual transmissions, as a rule, the clutch is automated.

Advantages and disadvantages

And finally, let's look at the pros and cons of manual transmissions. Let's start with the pleasant.

The cost of manual transmission is lower than that of any other boxes. They are also cheaper to repair and maintain, and they are required less frequently than on automatic transmissions. In addition, a manual transmission has a longer service life and is more difficult to break during operation. On average, depending on the model, a manual transmission “walks” 200-300 thousand kilometers, which in some cases is comparable to the service life of a car. The peculiarities of automatic transmissions are that they have a bunch of all sorts of rules that motorists consciously or unconsciously often violate, thereby reducing the life of the box.

A manual transmission increases the dynamic qualities of the car, as it has a higher efficiency and technical characteristics that favorably affect the acceleration of the car. In addition, given how much a manual transmission weighs (25-30 kg), compared to “automatic machines”, whose weight is at least 50 kg, it also leads to a decrease in the total mass of the car.

The advantages include also a large set of driving techniques on the "mechanics". The driver has the right to determine how to drive. This is especially true when driving off-road or on slippery roads.

The manual transmission is also good in “broken” situations. If you have a "mechanics", then you can start the car "from the pusher", as well as tow it to any distance and at any speed without damage to the box, which is absolutely impossible to do on the "machine".

Features such as no need for a separate cooling system and low fuel consumption also characterize the "mechanics" as a more advantageous option.

Perhaps the only drawback of a manual transmission is the very fact of interaction with it - the driver constantly needs to switch gears, synchronously manipulate the gas and brake pedals and monitor engine speed. This is especially annoying in traffic jams and creates inconvenience for novice drivers and for the fair sex.

Someone gets used to this need, and someone can’t put up with it, but be that as it may, manual transmissions are gradually becoming obsolete and, according to experts, the time will soon come when new cars will not be equipped with a manual transmission at all. Technological progress is relentless and the faster automatic transmissions improve, the faster people will abandon mechanical ones, but there will always be fans for whom the feeling of complete control over the car is more valuable than comfort.

The video demonstrates how to make a manual transmission with your own hands ... from 116 Lego parts. The downside of this box is that you won't be able to drive it, the upside is that it doesn't need gear oil.

Hello dear blog readers website. Today we will try to figure out which is better, automatic or manual, find out what checkpoints are how they differ and which gearbox is better to choose. Let me remind you, dear friends, that the type of transmission is one of the main car parameters, the choice of which is very important when choosing car brands and models.

What are the checkpoints?

First of all, let's understand the abbreviations, which denote car transmission types. In the descriptions of the equipment and in the advertisements for the sale of cars, next to the numbers of the engine size, we can see the following letters: AT, MT, AMT, CVT.

What do these letters mean?

• • . This is a manual transmission - the most reliable of all types of transmissions.
  • AT - Automatic transmission. Here it means precisely hydromechanical machine, and NOT a robot and NOT a variator
  • AMT - robot. These are old robotic transmissions, as well as modern dual clutch robots.
  • CVT - variator. This is a continuously variable type of automatic transmission, which we will discuss in more detail below.

Next, we will look at each type of transmission in detail, but first, let's find out: what is the gearbox for? Everything is very simple: without the ability to shift gears, automobile, in fact, will ride in only one first gear. He will be able to start and accelerate to the speed that the maximum crankshaft speed will allow to reach. And that's it! To continue further acceleration, it will be necessary to change gear. Thus, it can be concluded that checkpoint needed just for that so that the car can not only get moving, but also accelerate to high speeds so that he can go slowly when necessary, and quickly when necessary.

So, what are the types of checkpoints? First of all, all types of transmissions can be divided into mechanical And automatic. Let's see what is the difference between machine guns And manual transmission.

Operating principle manual transmission very simple. The driver, with the help of a lever, engages the necessary gears in the gearbox, as a result of which the desired gear is engaged. During gear changes, the clutch mechanism is used to disconnect the gearbox from the engine. If you want to understand how a manual transmission works, then this video will help you figure it out:

Machines with manual transmission have been produced for more than a century, and over many decades this unit has been brought to almost perfection. Modern manual transmission consists entirely of pluses. It is a model of reliability, economy, cheapness, lightness, and so on, and its only disadvantage is the need to shift gears manually.

Another important advantage of manual transmission often overlooked is its sheer ruggedness. Manual transmission, unlike the machine, literally, does not need to be serviced. Oil V mechanics necessary pour once, good, and all! You don't need to change it anymore. Next, you need to check the level and condition of the oil - this is 1-2 times a year. With good oil mechanical wear is minimal. Temperatures in manual transmission low, the oil does not burn, and therefore it can serve for years. Under normal operating conditions, manual transmission walks hundreds of thousands of kilometers on one oil. on the contrary, they are very sensitive to timely oil changes, and each maintenance of this delicate mechanism is expensive.

Another, implicit advantage manual transmission is the ability to easily start the engine “from the pusher”, if, God forbid, your battery runs out or the starter fails. By car with manual transmission, it will be enough to slightly push the car in neutral, and then turn on the third gear and the car will start. On automatic but such a trick will not work - you will have to look for someone to “light it up”, or take the car to the service, but only on a tow truck.

Speaking of towing: machine, in no case should it be dragged on a cable - each kilometer will reduce the resource of the checkpoint. Mechanics, on the contrary, you can put it in neutral and, having hooked on another car, carefully tow it to the place of repair - most importantly, do not forget that when the engine is turned off, the car's brakes almost do not work.

The main thing to pay attention to when choosing a car with manual transmission is the number of gears (steps). Modern manual gearboxes have from 4 to 7 steps, but ideal for mechanics- this is 5 or 6 steps (gears), I will explain why.

Four-speed mechanics is hopelessly outdated and is no longer installed on modern cars, so you can meet it only when buying a heavily used car. " four steps"has such a disadvantage that at high speed (over 120 km / h) it clearly lacks fifth gear, that is, to drive at high speed, in the highest fourth gear, the driver has to maintain high engine speeds, which has a bad effect on motor resource and on fuel consumption. However, the four-stage manual transmission It is quite suitable for you if you are a very calm driver and do not plan long high-speed trips.

Seven-speed manual is the other extreme. It allows you to quickly accelerate the car, and having reached maximum speed, continue to move at moderate engine speeds, but shift gears on the "seven steps" more often and it's not to everyone's liking.

We can say that the "seven-step" is the most mechanical of all manual gearboxes- work with a lever, on such a box, you have to do it the most. In general, the more gears in mechanical box, the faster the car can accelerate, but the more often you have to change gears.

So, let's summarize. In which case should you buy a car with a seven-speed manual transmission?

A seven-speed manual is right for you if:

• • It does NOT make it difficult for you to shift gears manually
  • The reliability of a manual transmission is important to you
  • You like high dynamics and full control over the car

Now, let's list again what is good mechanical transmission?

Benefits of a manual transmission:

• • The highest reliability among all gearboxes
  • Unpretentiousness (needs no maintenance)
  • Endurance (easily withstands heavy loads)
  • Economy (low fuel consumption)
  • Sporty character (dynamics and full control over the car)

Flaw at mechanics only one, and it is that mechanics - not automatic. On mechanics, you really need to shift gears, but whether this is considered a minus - everyone decides for himself. If you look from the other side, then manual transmission gives the driver full control over the car opportunity how to accelerate with the gas pedal, and effectively brake just letting her go. WITH mechanics the driver can be sure that without his command, the gear will not switch by itself, and the traction will not disappear suddenly, at the most crucial moment, as happens with the DSG robot. Personally for me, Mechanics- this is an ideal gearbox, which I will not exchange for any of the modern automatic machines - they are still very imperfect.

I hope, dear readers, now you know what manual transmission and how good she is. It is simple, like a Kalashnikov assault rifle, and therefore reliable, another thing is automatic transmissions- everything is not so simple here. there are several varieties, each has its pros and cons, but one thing can be said right away: all automatic boxes, in terms of reliability, strongly inferior to mechanics. Let's see what are modern automatic boxes and how they differ from each other.

Automatic transmission. Automatic, robot, variator: differences

It was invented in the middle of the last century and is rightfully considered one of the greatest inventions of mankind. Create automatic transmission engineers have been trying for a long time, and the first truly successful automatic transmission became a hydromechanical machine.

Let's look at each type automatic transmission, highlight the differences between them, and also list the advantages and disadvantages of each of them. Let's start with " classic slot machine"- the oldest of all types automatic transmission.

Hydromechanical gearbox (classic automatic)

Of all the options for automatic transmission, it was the first to be used on passenger cars. hydromechanical machine. Its history goes back over half a century, that's why hydromechanics called classic machine. For now, classic machine- this is the oldest, and the most elaborate design of all automatic transmissions. Like any automatic transmission, its reliability is incomparably lower than that of a manual transmission, but subject to careful operation and timely maintenance, classic machine can walk hundreds of thousands of kilometers without breakdowns.

The principle of operation differs significantly from manual transmission. The role of the clutch here is played by torque converter, and for gear shifting are used planetary gears And clutches.

The torque converter provides an incomparable ride And smooth shifting, therefore, in terms of comfort, classic machine This is the perfect checkpoint. However, smoothness is achieved due to the fact that the engine thrust is transmitted through the oil, and when it circulates, quite a lot of friction occurs - the torque converter can even heat up. As a result, classic machine has quite low efficiency, which manifests itself in increased fuel consumption.

minus hydromechanical gearbox is, also, big mass unit, which increases consumption and reduces maneuverability. On the other hand, all details classic slot machine(except for clutches) have a large margin of safety and, therefore, the “hydric” is easier than other machines to endure the “kick-down” mode (when the driver suddenly pushes the gas pedal). easily tolerates high torques, so machines with powerful motors are most often equipped with this particular type automatic transmission.

In respect of reliability, hydromechanical box shows best, among the machines, result, but only under the condition of careful operation and timely maintenance, which consists in replacing the ATF fluid and filter. Hydromechanics in general, it is very sensitive to the quality and condition of the filled fluid (ATF), which performs the work of transferring torque, lubricating gearbox parts and removing heat from heated elements.

The most vulnerable spot classic slot machine- frictions. They quickly fail if the car is not spared, while the wear products of parts clog the channels, the transmission fluid loses its properties and the machine starts to blunt, kick and twitch. To extend its service life the following things cannot be done automatically:

• • Trying to get off the road "jump"
  • Provoke frequent gear changes
  • Load an unheated machine in the cold season
  • Allow violation of the oil level in the gearbox

This mode of operation leads to accelerated wear, and this applies to machine guns all types. However, lowering the oil level and loading after a cold stop are harmful even for mechanical transmission.

used car with any automatically- this is a lottery, because it is not known how the previous owner performed maintenance, and how he treated his car. Used hydromechanics years may pass, or tomorrow it may stop shifting into gear and require expensive repairs, so a car with hydromechanical machine it is advisable to buy as new as possible.

Advantages of a hydromechanical automatic transmission:

• • Smooth ride and gear shifting
  • High reliability for a machine
  • Endurance

Disadvantages of the classic slot machine:

• • Increased fuel consumption
  • Large unit weight
  • It is highly desirable to warm up (to extend the service life)

classic automatic transmission. If in the first place for you is comfort, and fuel consumption is the last thing that worries you, then classic machine will be for you perfect choice. Also, hydromechanical gearbox ideal if you often have to stand in traffic jams, and if you plan to load your car quite heavily, for example, transporting a heavy trailer.

Recommend to buy classic machine new, do not load it too much in the first minutes, after a cold stop, change the ATF fluid in a timely manner and check its level more often, and then classic will please you more than one hundred thousand mileage.

Robot machine. Gearbox robot

When choosing a car for themselves, before buying, many are interested in,? We have already considered the classic automatic machine, but what is a robot gearbox? - This is a manual transmission, only supplemented by mechanisms that, instead of the driver and without his participation, squeeze the clutch and change gears.

The difference between an automaton and a robot is that classic machine transmission includes by braking the necessary parts of the planetary gear, and instead of a clutch it has a torque converter, and robot machine- This is a conventional manual transmission, but the computer controls the gears and clutch in it, using special drives. Robot, as if squeezing the clutch and shifting gears, instead of the driver. looks something like this:

Shows the same low fuel consumption, like a manual manual transmission, and this is its main advantage over other types of automatic transmissions. Besides, robotic mechanics is the most cheap option automatic transmission, which is why it is successfully sold, despite its significant shortcomings.

The main disadvantage of the robot is low reliability And fragility clutch release and gear change mechanisms. At first, the car robotic box can behave quite adequately: shift gears barely audibly, move off smoothly, smoothly release the clutch, and on the track turn on the desired gear in a timely manner, even when overtaking. But after a while, automatic robot it will definitely start to twitch, blunt, shift gears at the wrong time, make clanging sounds, etc. Unfortunately, robotic checkpoints while far from perfect and such behavior is the norm for them. What to do, the robot is not a person, it does not know how to squeeze the clutch as smoothly and sensitively, it does not know how to take into account the gradual wear of the clutch parts.

The robot does not like to crawl very much. For example, in a traffic jam, when you need to stop often, and then turn on the first gear again and move off. This mode of operation can bring the robot out of action in just a few hours.

The second moment that you need to know when buying a car with automatic robot are the features of the behavior of robotic mechanics. sometimes it's very thoughtful, and this can not only annoy the driver, it is generally dangerous when overtaking. To make a decision and change gear, automatic robot sometimes it takes up to 2-3 seconds (!), and a pause of 1 second is considered normal for the robot.

To deal with this problem, to some extent, allows the possibility manual gear shift, which is on everyone automatic robots. Before overtaking, the gear has to be manually forcibly lowered, and after overtaking, the driver again switches the gearbox to automatic mode and continues to “enjoy” the thoughtfulness inherent in the robot. However, consider: do you buy a car with automatic transmission in order to shift gears manually?

It is also unfortunate that take off on the rise without rolling back automatic robot succeeds not always. On a steep climb, before you start and go, the car can roll back by 1 meter and even more, and to combat this phenomenon, the driver must learn how to use the handbrake. For comparison: the classic automatic machine and the variator do not practice such a rollback on the rise.

So let's summarize a little automatic robot. Vehicles equipped robot, by nature are quite thoughtful, and over time, a machine equipped with robot, it also becomes twitchy. On a hill, the robot may roll backwards, so the driver must be able to use the handbrake. On the other hand, machines with robot have a lower price and consume less fuel than a classic automatic, so it's up to you to choose a robot or not.

Let's formulate what is the difference between robot and machine.

Advantages of the robot machine:

• Low price
• Low fuel consumption

Robot Disadvantages:

• overthinking
• Low reliability

In any case, if you are going to buy a car with automatic robot, then be sure to test drive in advance, feel the car, see how it behaves in different modes, and only then make a decision.

Do not buy a car with a robot if traffic jams are common in your city. A classic machine was simply created for traffic jams, and a robot is more suitable if you live outside the city and do not plan to stand in traffic jams at all.

If we continue to compare, what is the difference between robot and machine, then we can say that box machine robot- it was an attempt to automate the mechanics, and the attempt was not very successful. However, a few years ago, engineering thought moved in a new direction: the development of the second generation of robotic mechanics, the dual-clutch robot, was started.

DSG. DSG box - automatic dual clutch robot

is the most famous today dual clutch automatic transmission. Name DSG stands for Direct Shift Gearbox, and it translates as " direct shift gearbox».

DSG gearbox produces concern Volkswagen, so it can be found on cars of brands: seat, Skoda and actually Volkswagen, and here on Audi with a longitudinal engine, a similar gearbox is installed, but under a different name: S-tronic. Except DSG, is also quite famous dual clutch automatic entitled powershift, which is installed on cars of brands Volvo, Ford and others.

Preselective gearbox is another name dual clutch machines. Preselective checkpoint It is called so because right while driving in the selected gear, the automation predicts switching to the next gear and selects it in advance. Thus, the switching itself takes very little time: it is only necessary to open one clutch and close the second. Take a look at how it works dual clutch robot:

Dual clutch automatics- are second generation robotic manual transmissions. Let's try to figure out what DSG box better than usual robot, and what shortcomings have the designers failed to overcome yet?

Let's start with the fact that second-generation robots have learned not only change gear quickly they do it instantly(!). Gear changes now take a fraction of a second - faster than an experienced pilot shifts gears in a manual transmission. As a result, fuel consumption with a DSG box it turns out below than on mechanics, and dynamics overclocking - higher. It is also an achievement and reducing the weight of the unit. DSG weighs less than a classic automatic and even less than a CVT box (variator).

However, not everything is so rosy. The main disadvantage of the DSG box is design complexity. Complexity, in turn, creates low reliability, and high cost car and high cost of repairs and maintenance. In addition, not every car service can repair this complex device, so it will be nice if the dealer is located near your home or work.

Initially, low reliability DSG, begins to appear in traffic jams, as knocks, vibrations, possible overheating of the mechanism, and then jerks and bumps when shifting gears. With these symptoms, more and more car owners turn to service centers, demanding warranty repairs. We can say that the repair DSG boxes, in the very first years of operation, became commonplace.

In any case, before buying a car with DSG box, I strongly recommend that you, friends, search the Internet for something like the phrase " DSG problems”, especially if you are going to take it in a used condition.

Robot second generation, still doesn't like traffic jams. As a result of frequent gear changes, stops and starts, DSG box quickly fails. Robot dislikes crawling through traffic because he can't control the clutch as subtly as a human does. So here's my advice to you: don't buy a dual clutch car if you plan to be stuck in traffic for more than half an hour every day. If traffic jams are common in your area, and especially if you live in the capital, then it’s better to pay attention to the good old classic machine. Let the fuel consumption be a little higher, but believe me, hydromechanical machine Just built for traffic jams.

Let's recap all the pros and cons. DSG boxes– dual clutch robot:

Advantages of the DSG box:

• • Quick shifting, fast acceleration
  • Light weight and dimensions
  • Fuel economy

Disadvantages of the DSG box:

• • Low reliability and durability
  • Difficulty and high cost of repair

So, let's summarize a little. DSG gearbox suitable for you if you DO NOT plan daily stand in traffic jams, and the most important thing for you in the car is fast acceleration And fuel economy. At the same time, you should not be embarrassed by such small expenses as high car price, large repair and maintenance cost. Also, you should be prepared to give the car for warranty repair, that is, reliability should not be as important to you as the dynamic characteristics of the car.

And vice versa, if it is important for you, first of all, reliability And low consumption then choose manual transmission. If fuel consumption is not so important, and you want reliable automation then select classic machine. Robot the first generation is worth buying only if you really want at least some kind of automatic machine and at the same time really want save. Dual Clutch Robot DSG suitable if there are practically no traffic jams in your city, and low consumption and the sporty character of the car are more important for you than reliability. well and variable speed drive choose if you want exotic, however, oh variator below.

CVT gearbox. Variator or automatic?

Many car enthusiasts, before buying a car, begin to wonder: cvt box - what is it? Let's try to figure it out what is the difference between a variator and an automatic, what is the difference between an automatic and a variator and.

The difference between an automatic and a variator is that CVT variator shifts gears on a completely different principle, or rather, there are no fixed gears in the variator at all. If in a hydromechanical automatic transmission the gears are switched by blocking the necessary parts of the planetary gear, then in CVT gearbox the change in the gear ratio occurs steplessly - by changing the diameter of the shafts connected by the transmission belt.

By the way, this belt is the most loaded part of the variator, his Achilles' heel - the most vulnerable point. Just imagine: all the power of the engine is transferred to the wheels through this flexible belt. How long do you think it will last if the car is loaded to the fullest?

From the point of view of the consumer, is that the variator fuel consumption is lower, A higher acceleration dynamics, and this is not surprising, because CVT box does not waste time shifting gears, as all other gearboxes do. Besides, CVT constantly keeps the engine speed in the optimal range, therefore fuel consumption remains low, A accelerates car pretty fast. The role of the clutch variator box performs a torque converter (as on a classic machine), so smooth running CVT boxes similar to classic machine, perhaps a variator, in this regard, even better.

Besides, difference between automatic and variator is also in low durability CVT boxes. Resource CVT variator limited to a mileage of 100 thousand km (maximum 150-200 thousand), after which, as a rule, they change the entire box, because the repair of the CVT transmission is expensive, but the box is not enough after repair for a long time. Many owners of cars with a variator, after it breaks down, put in its place a more reliable hydromechanical gearbox. Fortunately, engineers design cars so that different types of gearboxes are interchangeable.

Also, difference between automatic and variator also consists in the fact that variable speed drive much less durable. CVT box type not designed for racing, it can not withstand heavy loads, does not tolerate high power and torque of the engine, so it is not paired with powerful motors.

Look, owners of CVT-equipped Mitsubishi Outlanders are discussing the problem of transmission-CVT overheating. This is the message the Japanese gives on the display of the on-board computer:

On the other hand, since CVT is much more "gentle" than a classic hydro-automatic, then for him even more heating is important in cold seasons. Operation without warming up leads to rapid wear of transmission parts, so the owners of new cars with a CVT try to get rid of them up to 100 thousand kilometers without waiting for problems.

Under light load, on light city cars, CVT variator can walk for years, but from excessive load it wears out literally before our eyes and fails very quickly. Under no circumstances should you drive a car. with CVT box transport a heavy trailer - this will quickly disable it. And if you still decide to take a chance by buying a used car with a CVT, make sure that it does not have a towbar.

On machines with a powerful engine, box type CVT the classic machine is not a competitor. The more powerful the engine and the greater the mass of the car, the less it will last. variable speed drive, therefore, on trucks and in racing cars CVT boxes do not apply.

The variator is contraindicated in excessive loads. Don't buy a car with a CVT for trailer hauling, racing, or off-roading.

How

Now let's try to figure it out how to distinguish a variator from an automatic? From the outside of the car, to distinguish a variator from an automatic it is impossible, even looking into the interior of the car. The gear selector does not allow distinguish what type of machine installed on a car, but you can to distinguish a variator from an automatic while driving this vehicle. Firstly, on a car with a CVT, during acceleration, the tachometer needle remains stationary, while the speedometer needle shows an increase in speed. Secondly, on a car with a variator, the noise of the engine, even during acceleration, does not increase, but remains the same monotonous buzzing - the computer keeps the engine speed stable, changing only the diameter of the shafts in the variator.

Many drivers consider this another lack of CVT transmission- lack of clear feedback from the car engine. The pilot does not feel the increase in speed, as is the case with a conventional stepped transmission. On the other side, variable speed drive constantly keeps the crankshaft speed in the optimal range, the engine never gains excessive speed, and this prolongs motor life.

At one time, the variator was a very promising type of transmission. It seemed that the engineers were about to be able to overcome its shortcomings and it would supplant other types of checkpoints, but these plans were never destined to come true. Company Audi for many years experimented with her variator under the trademark Multitronic, but as a result, it was decided to abandon the use of CVTs. Since 2014 Multitronic not installed on cars Audi, and the place of promising development was taken by dual clutch robotic transmission.

About that how to distinguish a variator from an automatic, I will also say that it is possible to assume which automatic machine is installed on a car if you know well which gearboxes were installed on a given brand of car, of a given model year. If you need to check the type of transmission you need before buying a used car, then you need to check with the seller Vehicle VIN and ask it in a special service on the Internet, so you can, in which it left the factory assembly line.

Let's list, once again, the pros and cons of a CVT transmission compared to others machine guns.

Advantages of the CVT box (variator):

• • Exceptional ride
  • Good dynamics
  • Low fuel consumption

Cons of CVT variator:

• • Low reliability
  • limited resource
  • High repair cost
  • Warm up is a must, otherwise it will quickly fail

In what case should you choose the variator? CVT box type suitable if you need an automatic transmission, with high smoothness and low fuel consumption. On the other hand, reliability should not be so important to you, or you buy a car new and plan to sell it as soon as the mileage exceeds one hundred thousand - before problems begin. variator.

All this makes sense if you use the machine in light mode, without excessive loads. If you plan to load the car in excess of the norm, carry a trailer or a full car of goods, then instead of a variator it would be better to buy a car with classic machine.

So, friends, I hope now you know about variator enough to decide whether it suits you or not. Now let's talk about adaptive transmission- what it is?

Adaptive called automatic transmissions with electronic control, which can get used to the driving style of the driver - adapt to it. remembers the manner in which the driver drives his car and adjusts the algorithms in such a way that the car behaves most conveniently for this particular driver: more dynamically or more economically.

Each of us drives a car in our own way, but there are two factors in the manner of each driver that are mutually exclusive - these are dynamism And economy. Raise speakers inevitably leads to growth fuel consumption, and vice versa, low fuel consumption is only possible with a calm driving style that excludes dynamics.

It takes into account how dynamically/economically the driver prefers to drive and acts as follows:

• • Dynamic style

The driver constantly presses the gas pedal to the floor.
The computer supplies more fuel to the engine, shifts gears so that the engine always runs at maximum torque. The car goes into sport mode, becomes more collected and dynamic, but fuel consumption becomes higher.

• • Economy Style

The driver accelerates smoothly and slowly.
The machine switches to economy mode, in which less fuel is supplied, the gears are engaged at lower speeds, which saves fuel.

Advantages adaptive gearbox obvious - it allows each driver to get the right combination of dynamics and efficiency, and for this you don’t even need to do anything: the computer will adapt itself within a few minutes after the start of the trip. If we talk about how much you need to drive for the box to adapt to your driving style, then almost all modern adaptive automata spend no more than half an hour of continuous movement on it.

First adaptive gearboxes were classic automatic transmissions, but now manufacturers are laying self-learning and adaptation algorithms in all types of automatic transmissions, moreover, most modern machine guns are adaptive. Another thing is that each manufacturer has its own learning algorithms, they are different and do not work equally well on all machines.

In addition, most modern adaptive gearboxes, have a special button for forced change of the sport/comfort mode. This allows you to "wake up" the car if it is in economy mode and vice versa "calm" if it behaves too briskly.

Now let's compare everything types of checkpoints among themselves, and try to decide which one will suit you more than others.

Automatic or mechanic? Which gearbox to choose?

To begin with, we need to decide: Automatic or mechanic, what to choose? Everything is simple here.

Take mechanics if:

• • You need absolute reliability
  • Doesn't make it difficult for you to shift gears manually
  • You like dynamics, economy and full control over the car
  • You do not mind saving on maintenance and possible repair of automatic transmission

Choose an automatic machine in cases where:

• • You need an automatic (don't want to change gears manually)
  • Reliability, for you, is not as important as automation
  • You are wealthy enough to pay for the use of the vending machine

Choosing automatic or manual, consider the fact that it is better to take a used car on mechanics. almost eternal, but shabby machine can cause a lot of trouble for the new owner. From reliability and unpretentiousness manual transmission follows its ability, over time, to maintain the original price - a car with manual transmission depreciates more slowly.

minus all machine guns is that they do not tolerate slippage and buildup. You can’t do without these measures if you landed in mud, snow or an icy rut, but you can use buildup and slip only on manual transmission- on automatic doing so is prohibited. From half an hour of such bullying, even a brand new one machine can fail, so for serious off-road driving, choose only mechanical box.

Which machine to choose: robot, CVT or machine?

We have considered three types automatic transmission, which are widely used on passenger cars, and now we need to decide which machine to choose and in what case. We list, once again, the main types of automatic transmissions.

What are automatic transmissions?

• CVT (CVT gearbox)

Choosing type of automatic transmission, as in the case of mechanics, one must pay attention to number of steps at the checkpoint. Four-speed automatics are gradually becoming a thing of the past - they are gradually being replaced by more modern 6-8 and even 10-speed units. However, four-stage machine easier their modern counterparts, and therefore more reliable. Wherein, more modern 6-8 speed boxes save fuel And accelerate faster, but they more difficult by device and less reliable. All this concerns classic slot machine And robot DSG, but not variator, because in CVT box the number of gears is close to infinity.

Very suitable if you need a high for the machine reliability And smoothness gear shifting, and increased fuel consumption does not bother you. dynamics hydromechanical machine a little lower, but its disadvantage is usually compensated by a powerful motor working with it in tandem. For serious off-road trips, you only need to choose manual transmission, but if you really choose an SUV with automatically, then it must be hydromechanical transmission- She is more resilient. However, let's compare classic machine and other types of automatic transmissions.

Automatic or CVT? What's better?

To answer the question what is better automatic or variator, it is necessary to remember that they differ in the principle of gear shifting, and therefore in design. At the same time, it must be said that the design CVT variator much less reliable than the design classic automatic transmission.

What to choose automatic or variator? Perhaps you should choose a variator if you are buying a new car and plan to change it before the mileage exceeds 100 thousand km. If the car is used, then be prepared for a possible exit. variator out of order, the repair of which can cost 2-3 thousand dollars.

The automatic machine is better than the variator in the following parameters:

• • More reliable
  • Hardier, you can drag a heavy trailer (boat, for example)
  • Easier to repair

The variator is better than the machine in the following parameters:

• • Less fuel consumption
  • Above speaker

By smoothness classic machine And variable speed drive are approximately equal, but if we compare by indicator, variator or automatic which is more reliable, That classic machine shows in order greater reliability compared to the variator. I hope you now know which is better: automatic or variator.

Robot or machine? What's better?

Now, dear readers, you know enough to decide for yourself what is better machine or robot. It is important to take into account that robots there are old and new generations - dual clutch. old robots made from conventional manual transmissions, they are characterized twitch and twitch even in new condition. Needless to say, after a short run in traffic jams, such a masterpiece begins to twitch more and more. And here second generation robots have achieved some success - they change gears very quickly, consume even less fuel, but they still do not like to crawl in traffic jams.

To sum up: why is a robot gearbox better than an automatic machine, and by what parameters classic machine still wins robotic checkpoints.

First generation robots are better than automatic:

• • Lower car price
  • Less fuel consumption

Second generation robots (DSG box) are better than automatic:

• • Better acceleration dynamics
  • The lowest fuel consumption of all automatic transmissions

In turn, a classic machine is better than a robot in that it:

• • More reliable
  • hardier
  • Moves smoothly and shifts gears

That's all, dear readers! Perhaps that's all I could tell you about choosing a gearbox for your car. Now, knowing all this, you can decide

Almost any modern car (except electric cars) is necessarily equipped with a gearbox. The most popular are the following types of gearboxes:

1. Automatic transmission;
2. Variable speed drive;
3. Robotic gearbox.

The most common in Russia is a manual transmission. Almost all domestic cars and most foreign cars are equipped with boxes of this type.

Purpose and device of a manual transmission

A manual gearbox is needed in a car to change the gear ratio from the engine to the wheels. Gear shifting occurs due to the muscular strength of the driver, his mechanical efforts in relation to the manual transmission. That is why such a gearbox is called a manual gearbox. The driver himself controls when to shift the manual transmission selector to a higher or lower gear. Modern manual transmissions are 5, 6 and even 7-speed. Most often in modern cars a 6-speed gearbox is used.

In addition, each manual transmission box has a reverse and neutral gear. The rear one allows the car to move backward, the neutral gear is when there is no rotation from the motor to the drive of the drive wheels.

The principle of operation of a manual transmission

The manual transmission device includes:

1. The box itself, which is a multi-stage gearbox;
2. Clutch;
3. Various shafts and gears.

If you explain the principle of operation of manual transmission for dummies, then you can form it like this:

1. The gears change the speed between the shafts. By changing the size of the gears, there is a switch to an up or down gear;
2. Without a clutch, shifting gears on the go is impossible. His job is to separate the motor and transmission. This procedure helps to shift gears without breaking the gears and shaft.

Each manual transmission (if it is not an innovative model) is arranged according to a similar design. Gears are located on the shafts (on their axes). Manual transmissions come with two or three shafts, and the housing is called the crankcase.

Three-shaft system device

The three-shaft system is equipped with three shafts:

1. drive shaft;
2. intermediate shaft;
3. Driven shaft.

The principle of operation of the mechanics is that there are splines on the drive shaft, and the shaft itself is connected to the clutch. The clutch disc moves on the splines, and the axle itself transfers its energy to the intermediate shaft, which is connected to the drive gear.

The driven shaft of a mechanical gearbox is connected to the drive shaft with the help of a bearing inside the first shaft and is located in such a way that the axes of the driven and the drive are related to each other. In turn, this structure allows them to rotate independently of each other. The gears of the driven axle are not rigidly fixed in relation to the driven shaft, and the gears themselves have special delimiters - a synchronizer clutch. Such delimiters, unlike gear blocks, are firmly attached to the driven shaft. However, this does not prevent them from moving along the spitz along the axis.

The ends of the synchronizer coupling are in the form of gear rims, which allows them to come into contact with the rims on the ends of the driven shaft gears. Currently, the gear unit is equipped with such synchronizers in all forward gears.

Delimiters-couplings in the neutral mode, which is characterized by smooth rotation of the gears, are disengaged. At the moment of switching the lever to one of the possible steps with the clutch fully depressed, the fork in the gearbox directs the synchronizer clutch to come into contact with its pair at the end of the gear. This engagement gives a rigid fixation of the gear with the shaft and, as a result, the transmission of force and rotation.

With a rear-wheel drive type of car, the transmission of torque and revolutions to the drive wheels occurs through a cardan shaft, and with a front-wheel drive - using CV joints and a gearbox. In the event that there is no gear, and the clutch directly engages the driven and drive shafts, the gearbox gives the highest possible efficiency. For reverse gear, the box device is equipped with a gear that allows you to change the direction of rotation in the reverse order.

Recently, manual transmission manufacturers have been favoring helical gears. Unlike spur gears, such gears produce a minimum of noise during operation and are more wear resistant. The service life of such gears is determined by the material from which they are made: high-alloy steel, hardened by high frequency current and normalized to relieve stress.

Double shaft device

The operation of a manual transmission equipped with a two-shaft gearbox follows the same principle as a three-shaft one. The only difference is the gear layout. Instead of one on the drive axle, there is a whole block of gears. There is no intermediate shaft, but the two remaining shafts run parallel to each other.

In general, a two-shaft system has a high efficiency, but the gear ratio on such systems is quite low. It is for this reason that two-shaft gearboxes are installed only on cars. For trucks, the gear ratio should be higher.

What is the purpose of a synchronizer in a manual transmission?

Most passenger cars, both domestic and foreign, have manual transmissions that have a synchronizer. This element helps to equalize the speed of the gears, which leads to reduced noise levels and easier gear shifting, which cannot be achieved if there is no synchronizer in the box.

How does the gear change process work?

No matter what kind of drive in your car, front or rear, a special lever is always responsible for the gear shifting process. If you look at the manual transmission in section, you will notice that the location of the lever on the front drive is significantly different from its location on the rear drive.

Rear-wheel drive vehicles have a simpler shift lever layout, which simplifies their repair and maintenance. The lever is located directly on the gearbox housing, the shift mechanism is hidden inside the housing. This location has many advantages, but, unfortunately, it is not without its disadvantages.

Design advantages:

1. A very simple solution, which greatly simplifies the process of do-it-yourself repair;
2. Gear shifting is very precise;
3. Due to the absence of "extra" knots, this design is very durable.

Design cons:

1. It is not possible to install this system on vehicles with front-wheel drive;
2. If a car with rear-wheel drive has an engine located at the rear, then this also makes it impossible to use this design (there are very few such cars).

On front-wheel drive vehicles, the gearshift lever can be located in the following places:

1. On the floor, between the front seats;
2. Directly on the steering column;
3. Near the dashboard.

This feature leads to the fact that the multi-speed manual transmission on front-wheel drive vehicles only works remotely, using backstage or rods. This design feature also has its pros and cons:

1. The lever is located more comfortably for the driver, since its position does not depend on where the manual transmission is located;
2. The vibration that is created in the gearbox is not transmitted to the gearshift lever;
3. Opens up a wide field of activity for automotive designers who can place the gearshift lever in any place convenient for them.

The disadvantages of this design are as follows:

1. A more technically complex system requires more attention and is less durable;
2. After long-term operation, backlash often appears;
3. There is no such clarity of gear shifting as in the version with a gearbox on a rear-wheel drive car;
4. Periodically, it is necessary to adjust the traction, which may require qualified intervention by car service specialists.

Advantages and disadvantages of manual transmission

Any system, including a gearbox, has several different designs with different pros and cons. Consider how a manual transmission differs from other types of gearboxes:

• The main advantage of using manual transmission is its price. Most budget cars are equipped with mechanics. Of course, you should not expect that a six-speed manual transmission or the latest seven-speed mechanics will be installed on a “state employee” (such boxes are sometimes mistakenly called seventh generation boxes);
• If we compare the manual transmission with hydromechanics, then the manual transmission will be much lighter in weight and have a higher efficiency;
• Manual transmission does not require such cooling as automatic transmission;
• Simplicity and reliability of the design (even in the version with manual transmission for cars with front-wheel drive);
• Cars with manual transmission are more economical than those with automatic transmission (this does not apply to the latest automatic transmission models, which can be more economical than "mechanics");
• Repairing a car with a manual transmission does not cause difficulties and can be done independently;
• Manual transmission is more suitable for sports cars, allowing the use of extreme driving techniques, controlled skidding and so on;
• A car equipped with a manual transmission can be started by pushing, and if it doesn’t work out, then towed to any desired distance.

Disadvantages of the manual transmission are as follows:

• Gear shifting takes longer than when using automatic transmission, as there is a separation of the engine and transmission at the time of shifting;
• For smooth gear shifting, driving skills with this type of gearbox are required;
• The clutch often fails and needs to be replaced;
• When driving a car with a manual transmission, the driver gets tired more, as he is forced to constantly change gears. This problem is especially relevant in large cities.

Gradually, the global automotive industry is reducing the number of cars with manual transmission, especially for the markets of countries with a high standard of living.

Manual transmission maintenance

Maintenance for a manual transmission usually consists of checking the oil level in it. It is necessary to monitor whether there are smudges on the crankcase, joints and filler and drain plugs.

Cars equipped with an on-board computer can signal to the owner about problems with the manual transmission unit. Each computer signal is decoded, after which appropriate measures are taken. The decryption can be in the manual for your car or in a special program on a laptop that can be connected to the car's on-board system. In most foreign cars, the oil in the box does not change if there are no problems. It is only necessary to occasionally check its level (if there are no signs of leaks).

Manual transmission is a fairly simple and maintainable system. If you need a simple and reliable car, then choose a car equipped with a manual transmission.

If you have any questions - leave them in the comments below the article. We or our visitors will be happy to answer them.

Cars with a manual transmission, which is abbreviated as manual transmission, until recently made up the vast majority among other vehicles with different ones.

Moreover, a mechanical (manual) box remains a fairly common device for changing and transmitting engine torque today. Next, we will talk about how the "mechanics" is arranged and works, what the gearbox scheme of this type looks like, and also what advantages and disadvantages this solution has.

Read in this article

Manual transmission diagram and features

To begin with, this type of gearbox is called mechanical due to the fact that such a unit involves manual gear shifting. In other words, on cars with manual transmission, the driver himself switches gears.

We go further. The "mechanics" box is stepped, that is, the torque changes in steps. Many motorists know that the gearbox actually has gears and shafts, but not everyone understands how the unit works.

So, a stage (it is also a transmission) is a pair of gears (driving and driven gear) interacting with each other. Each such stage provides rotation with one or another angular velocity, that is, it has its own gear ratio.

Under the gear ratio should be understood as the ratio of the number of teeth of the driven gear to the number of teeth on the drive gear. In this case, different stages of the box receive different gear ratios. The lowest gear (low gear) has the largest gear ratio and the highest gear (high gear) has the smallest gear ratio.

It becomes clear that the number of steps is equal to the number of gears on a particular box (four-speed gearbox, five-speed, etc.) previously 4-speed manual transmissions have gradually faded into the background.

Manual transmission device

So, although there can be many designs of such a box with certain features, however, at the initial stage, two main types can be distinguished:

• three-shaft gearboxes;
• two-shaft boxes;

A three-shaft manual gearbox is usually installed on rear-wheel drive cars, while a two-shaft gearbox is placed on front-wheel drive passenger cars. At the same time, the device of mechanical gearboxes of both the first and second types can differ markedly.

Let's start with a three-shaft mechanical box. This box contains:

• the drive shaft, which is also called the primary;
• intermediate shaft gearbox;
• driven shaft (secondary);

Gears with synchronizers are installed on the shafts. The gearshift mechanism is also included in the gearbox. These components are located in the gearbox housing, which is also called the gearbox housing.

The task of the drive shaft is to create a connection with the clutch. The drive shaft has slots for the clutch disc. As for the torque, the specified torque from the input shaft is transmitted through the gear, which is rigidly meshed with it.

Affecting the work of the intermediate shaft, this shaft is located parallel to the input shaft of the gearbox, a group of gears is installed on it, which is in rigid engagement. In turn, the driven shaft is mounted on the same axis as the drive shaft.

Such an installation is implemented using an end bearing on the drive shaft. This bearing includes the driven shaft. The group of gears (gear block) on the driven shaft does not have a rigid engagement with the shaft itself and therefore rotates freely on it. In this case, the group of gears of the intermediate shaft, the driven shaft and the gear of the drive shaft are in constant engagement.

Synchronizers (synchronizer couplings) are installed between the gears of the driven shaft. Their task is to align the angular velocities of the gears of the driven shaft with the angular velocity of the shaft itself through the force of friction.

Synchronizers are in rigid engagement with the driven shaft, and also have the ability to move along the shaft in the longitudinal direction due to the spline connection. Modern gearboxes have synchronizer clutches in all gears.

If we consider the gearshift mechanism on three-shaft gearboxes, often this mechanism is installed on the unit body. The design includes control levers, sliders and forks.

The box body (crankcase) is made of aluminum or magnesium alloys, it is necessary for installing shafts with gears and mechanisms, as well as a number of other parts. There is also gear oil (gearbox oil) in the gearbox housing.

• To understand how a three-shaft type mechanical (manual) gearbox works, let's look at the principle of its operation in general terms. When the gear lever is in the neutral position, there is no transmission of torque from the engine to the vehicle's drive wheels.

After the driver moves the lever, the fork will move the synchronizer clutch of one or another gear. Then the synchronizer will align the angular speeds of the desired gear and the driven shaft. Then the gear ring of the clutch will engage with a similar gear ring, which will ensure that the gear is locked on the driven shaft.

We also add that the reverse gear of the car is provided by the reverse gear of the gearbox. In this case, a reverse idle gear mounted on a separate axle allows the direction of rotation to be reversed.

Two-shaft manual gearbox: device and principle of operation

Having dealt with what a three-shaft gearbox consists of, let's move on to two-shaft gearboxes. This type of gearbox has two shafts in its device: primary and secondary. The input shaft is the driving one, the secondary is the driven one. Gears and synchronizers are fixed on the shafts. Also in the crankcase of the box is the main gear and differential.

The drive shaft is responsible for connecting with the clutch, and there is also a gear block on the shaft in rigid engagement with the shaft. The driven shaft is located parallel to the drive shaft, while the gears of the driven shaft are in constant engagement with the gears of the drive shaft, and also rotate freely on the shaft itself.

Also, the drive gear of the main gear is rigidly fixed on the driven shaft, and synchronizer couplings are located between the gears of the driven shaft. We add, in order to reduce the size of the gearbox, as well as increase the number of gears, in modern gearboxes, 2 or even 3 shafts can often be installed instead of one driven shaft.

On each such shaft, the gear of the main gear is rigidly fixed, while such a gear has a rigid engagement with the driven gear. It turns out that the design actually implements 3 main gears.

The main gear itself, as well as the differential in the gearbox device, transmit torque from the secondary shaft to the drive wheels. In this case, the differential can also provide such rotation of the wheels when the drive wheels rotate at different angular speeds.

As for the gearshift mechanism, on two-shaft gearboxes it is taken out separately, that is, outside the body. The box is connected to the switching mechanism by cables or special rods. The most common connection is with cables.

The shift mechanism of the 2-shaft box itself has a lever, which is connected by cables to the selector lever and the gear shift lever. These levers are connected to the central shift rod, which also has forks.

• If we talk about the principle of operation of a two-shaft manual gearbox, it is similar to the principle of a three-shaft gearbox. The differences are in how the gearshift mechanism works. In a nutshell, the lever can carry out both longitudinal and transverse movements relative to the axis of the car. During lateral movement, gear selection occurs as force is applied to the gear selection cable, which acts on the gear selector lever.

Further, the lever moves longitudinally, and the force goes to the gearshift cable. The corresponding lever horizontally moves the stem with the forks, the fork on the stem displaces the synchronizer, which leads to blocking of the driven shaft gear.

Finally, we note that also mechanical boxes of different types have additional blocking devices that prevent the inclusion of two gears at the same time or an unexpected gear disengagement.

Read also

Depressing the clutch before starting the engine: when to depress the clutch and in what cases it is not recommended to do so. Useful tips and tricks.

Causes of difficult gear shifting on a running engine. Transmission oil and level in the gearbox, wear of synchronizers and gears of the box, clutch.