What are the gearboxes of the car. Detailed description of the four types of checkpoints

16.07.2019

Cars have now stepped far forward, literally every year we hear about innovations that are designed to improve driving performance. Gearboxes are no exception in this, if at the dawn there was only one transmission - mechanical, now there are at least four of them. Many of my readers ask me to make a review article about their types, as well as “fluently” talk about their differences. Well, read the review article, it will be interesting, by the way, at the end, as usual, the video version ...

As usual, let's start with a definition.

Transmission or "gearbox" G ear B ox) - this is a unit that is designed to transmit engine torque to the wheels, using special mechanisms inside, as well as from external factors(driver behavior) - can increase or decrease the torque.

Now there are not only mechanical boxes gears, but also fully automatic, where human participation is minimized. You can argue for a long time which is better or worse (this was done here), but modern drivers vote for automatic machines, in Russia their number is growing every year, and almost exponentially.

As I wrote above, now there are 4 generally accepted types of transmissions:

Mechanical (abbreviated manual transmission or "mechanics")
Automatic torque converter (automatic transmission or classic "automatic")
Automatic CVT (CVT)
Automatic robotic ("Robot" or RKPP)

To be completely honest, now there are varieties of so-called hybrid transmissions, but this is the topic of another article, because electric motors are often used there (the article will be, but a little later).

And now let's still talk about our types of gearboxes, let's start with the "mechanics".

Manual Transmission

It was created almost together with the first cars, its age is more than 100 years. However, when she appeared, she had only 3 gears - two forward and one back. With the evolution of motors, there was a need for 3 gears forward and one reverse. And only in the 70s - 80s were 4 forward gears introduced, by the way, they lasted quite a long time, because almost 30 years passed before the appearance of the "five-steps".

Now, by the way, evolution has reached 6 “forward” gears (or as they are called speeds) and one back. As many designers say, this is almost the peak of the evolution of mechanics. YES, and imagine an 8 “speed” agitator, drivers will be confused.

Who is this transmission for?

She has a lot of fans, because here you completely control the transmission of torque to the wheels of the car, and until you switch yourself, no electronics will do anything for you. It should be noted that many sports cars, whether it's "drifting" or racing on rough terrain, it is the mechanics that are chosen, the skill reaches such heights that you can start the cars in a controlled skid, for example, giving increased torque to the wheels. It will also be useful off-road, because the machines can heat up and even fail when the wheels slip, but on the mechanics you can slip as much as you like. With a certain skill, gear shifts are faster - which definitely has a positive effect on the dynamics of acceleration, since the mechanics are almost a second faster than the same car with a gun.

Device - mechanics is divided into two types - these are options with "two" shafts and "three". Some cars mainly use two shafts (leading and driven), others three (leading driven and intermediate), for example - on the VAZ classic there are exactly three of them. The presence of two or three does not speak of some kind of “superpower” of the machine, rather, everything here is all about the drive and the layout of the box itself. Device at front wheel drive strikingly different from the rear, here you have the differences in gearboxes.

What else would you like to say - if you drive a manual transmission, then you are most likely already accustomed to three pedals, because here one more node is added - the clutch. It is needed for smooth gear shifting, although many "new drivers" learn to control it for a very long and tedious time, especially big problem deliver slides.

Pros of mechanics :

low cost
light weight
Uses little oil
Possibly roll over. Don't be afraid to tow your car
You can start the car from the pusher, nothing bad will happen
Transferring more efficiency from the engine
Easier start in winter

Cons of mechanics :

Difficult to control, especially for beginners
You can easily burn the clutch, again by beginners
An additional node is added, such as a clutch
The Ferado disc in the clutch structure wears out faster

Whatever one may say, but the mechanics “so far” are the leader in terms of the number of sales in Russia, our harsh climate affects - after all, it’s not scary to slip on it, and it’s also easier to start in the morning in frost (although there’s still a need to argue), and the cost about 40 - 50,000 rubles lower, which is also a big plus.

Robot or robotic box (RCP)

"BUT wait" - you tell me - "Why is the robot walking now, because there are more - such species as, why did you jump like that?". The question is what is said - "not in the eyebrow, but in the eye." I jumped because robots are a continuation of mechanics, no matter how trite it may sound. Such boxes took all the advantages of manual transmission and automatic transmission, but they also have plenty of disadvantages.

If you say in simple terms, then it turned out such a structure : - on a regular mechanical box, attached special servos or electronic drives, which have taken over the functions of the clutch, that is, they change gears, so there is no third pedal - there is only gas and brake like on a CVT or automatic. But there is also a clutch disc, and even a basket, the same shafts (driver and driven), only the electronics manages all this, which in fact is the “Achilles heel”.

They have not yet created perfect switching mechanisms for robots, all these boxes are slow - thoughtful, switching is slow, and also very unreliable due to many electronic components.

Pros of a robot :

Makes shifting easier, no need to think about the clutch
Saves fuel, like mechanics
Can ride on
Can be towed without fear
A little oil in the structure (comparable to mechanics)

Cons of the robot :

Thoughtful
Switching occurs with shocks
Observes a slight rollback at the start, it is dangerous on a hill, because another car may be standing behind

Many believe that such types of manual transmissions are the future, it is quite possible, because electronics are developing, and they are being made more compact and perfect. The biggest success so far has been Volkswagen, FORD and BMW.

Classic "automatic" or torque converter

This is also an “ancient” transmission that appeared about 100 years ago, only now it found its first application on ships, where it “connected” the drive screw and shaft. After that, the types of these automatic transmissions migrated to cars.

Now they are used very widely, as well as mechanical types, at first they were at 3, later at 4, and now they already exist for 8 gears. Progress does not stand still.

In this box, there is practically no clutch at all in the understanding of mechanics,. Here, the transmission of torque engaged in hydrotransformer. To exaggerate, this is a special "turbine" - which transfers oil pressure from one impeller to another. They do not have a rigid clutch between them, but only oil pressure. One "impeller" is connected to the engine and receives torque from it, the other is connected to the shafts, and then to the wheels.

This type of gearbox uses a large amount of oil in its structure (it is specially designed for automatic machines of this class), usually, if you count in liters, this is from 8 to 12.

Automatic machines in their structure can differ in adaptive and driver-controlled.

Adaptive - automatically adjust to the driving style, for example, if you always "fry to the floor", then the shifts will help to quickly pick up speed, but there will be no savings. If you drive carefully, with low revs, and also at a low speed, then shifting will contribute to a measured ride, as well as fuel economy. Adaptation takes place at the level of the ECU, where data is accumulated, and the first "modes of behavior" may already appear after the first 100 kilometers.

Adjustable - these are types of machines that are completely subordinate to the action of the driver. They usually have several modes - SPORT, ECONOMY, CLASSIC (CITY) and WINTER. Some manufacturers may have up to 7 - 8 of them. That is, you yourself choose the “button” you need for yourself.

Advantages of the machine :

Ease of driving (especially for beginners), no clutch pedal.
Durability and unpretentiousness. Modern views automatic machines are strong enough, I would say with proper maintenance, it goes through the entire life of the car
Protects the motor quiet ride(city mode or economy), does not tear it.
Smoothness of work, now almost all automatic machines are deprived of strong jerks and shocks when switching, which gives smoothness and comfort of movement.
It’s a pleasure to drive up hills, a car with automatic transmission will not roll back, for newly minted drivers it’s just a salvation.

Cons of automatic transmission :

A large amount of oil in the transmission, a long warm-up in winter, as well as a more difficult start
It is undesirable to slip, otherwise the oil may “boil”, which can lead to breakage.
Difficult and expensive repairs
Low efficiency, because there is no rigid connection with the engine
Greater fuel consumption
Loss in accelerating dynamics
It is undesirable to tow, you need to call a tow truck

Despite the disadvantages of this transmission, its popularity is growing rapidly, this is understandable because now there is very tough traffic in cities, and clutch is an unnecessary loss of concentration. If we sum up by technical reliability of this type of gearbox, then with proper maintenance - an oil change, it can last at least 300 - 400,000 kilometers, and possibly more.

CVT (variator gearbox)

The latest type of automatic "boxes". However, this type, in my opinion, competes strongly with conventional "torque converters". In the cabin, you will also not find a clutch pedal, but only gas and brake.

On the Internet, you have probably heard about continuously variable transmissions, which transfer torque from the engine to the wheels very efficiently, so this is it. She has no shifts at all in the understanding of other gearboxes.

There are also two shafts - on which there are gears with a changing diameter, a special belt is stretched between them. When the car starts moving, then on one shaft (driver) there is a large diameter gear, but on the driven one, on the contrary, the small one, the car needs to accelerate, with such a selection of gears this is done ideally.

After the speed is gained, the drive gear begins to decrease, reduce its diameter, but the driven one, on the contrary, begins to grow, thus, at low engine speeds, the required torque is transmitted to the wheels. It should be noted that the variator has a higher efficiency than the machine, because there is a rigid connection.

As you can see, there are no steps here, but only smooth transition belt "on the radii", so you do not feel any jerks and shocks, only "clear" and smooth acceleration and the same smooth deceleration, if you throw off the pedal.

There are only three types of variators currently used on machines:

Belt or CVT, the most common (used in 90% of cases)
Clinomeric
toroid

The last two are rarely used in the automotive industry, the application is most likely in special equipment.

If we talk about dynamics and acceleration, then the CVT gives excellent performance, which sometimes exceed conventional mechanics, and even more so the machine and the robot.

Advantages of the variator :

Ease of use
Greater operating efficiency
Dynamic acceleration
Fuel economy
No jerks or jerks - at all
Easy to move uphill

4,80

Every year, more and more automakers notify us of the appearance of the latest technologies to improve the car's cross-country ability, acceleration dynamics and other characteristics.

As a rule, this applies not only to the engine, but also to the transmission. In this article, we will look at Various types Gearbox, manual transmission, and also what are the automatic transmissions on a car other than a manual one.

Read in this article

Gearbox types

The transmission (gearbox) provides transmission to the wheels, while the gearbox is a mechanism by which the torque is converted (increase or decrease), change in speed and direction of movement.

There are four generally recognized types of transmission:

(known as "manual" or "manual" transmission);
(automatic torque converter gearbox);
(robotic gearbox);
(stepless, CVT gearbox);

As you can see, in addition to mechanical gearboxes, engineers have also developed an automatic transmission, which greatly facilitates driving. Today, drivers get the opportunity to choose in favor of the mechanics or the machine of one type or another. Let's look at the types of gearboxes in more detail.

Mechanical (manual) gearbox

The first gearbox was a mechanical one, which was designed even at the time of the advent of cars. Initially, such a manual transmission consisted of two gears (one forward and one reverse). After a while, the engines became more powerful, as a result of which the unit received three gears forward and one back.

Soon, they developed four forward gears at all. Such gearboxes were the standard for quite a long time before five gears appeared (the so-called “five-speed” box). But the modification process did not stop, so further manual transmissions began to receive six, seven and even eight gears (speeds) forward and one reverse.

Today the standard is five-speed gearbox, many drivers choose this type of manual transmission. The main advantage is reliability and the ability to personally control the transmission of torque to the wheels of the car, which allows you to fully control the car.

It should be noted that many sports cars are often equipped with mechanics, since this type of transmission allows the driver to perform “drifts”, to break the car into controlled skid etc. With automatic transmission it is very difficult or even impossible.

You can also highlight other advantages of manual transmission. For example, the engine can be spun up to maximum speed, flexibly switch from high to low, without much risk to operate the car off-road, tow a trailer and other cars, etc.

There are two main types of mechanical box: with 2 shafts and 3. In the first case, a two-shaft box has a drive and a driven shaft. The second also has an intermediate shaft, and the box itself is three-shaft. The two-shaft and three-shaft type of mechanics has some differences, but they are not fundamental.

Drivers operating mechanics know from experience that the device has. Inside the car there is a third pedal that allows you to turn on / off the clutch. The clutch is designed to transmit torque, and disengaging it allows you to shift gears and do it smoothly.

So, we can distinguish the following advantages of the manual transmission:

affordable cost;
light weight;
economy and ease of maintenance;
a small amount of gear oil;
the ability to actively operate the vehicle;
it is allowed to push the car when starting the engine;
ease of starting in the cold season.

There are also disadvantages of manual transmission:

various difficulties and difficulties in driving (more often observed in novice drivers);
the need to change the clutch every 80-100 thousand km. run;
the risk of burning the clutch ahead of time (usually for an inexperienced driver);

Hydromechanical automatic transmission with torque converter

This type of gearbox consists of two devices - the gearbox itself and. GDT was originally used on ships, realizing the connection between the lead screw and the shaft. Later, the solution began to be applied on cars, and the torque converter itself is an automatic transmission clutch. This type of gearbox appeared a long time ago and is no less common than manual transmission. Initially, the machines had three gears, but today their number reaches eight gears (like the "mechanics").

The difference between "automatic" and "mechanics" is the absence of the usual friction clutch. Simply put, the torque converter is actually a turbine, transmitting torque through oil ( ATF fluid) on the impellers. The first impeller is attached to the engine flywheel, and the second to the box shaft.

Also in the box is a set planetary gears and , in which oil also circulates through the channels under pressure. The oil in this case acts on executive mechanisms, allowing you to turn gears on and off in automatic mode. It is not difficult to guess that such an automaton, taking into account a number of features, needs in large numbers oil (can reach up to 12 liters or more).

Today, machines of this type can be or have a mode, as well as a number of other additional modes. Tiptronic is an imitation manual mode, that is, the driver independently shifts gears "up" and "down". The adaptive look of the machine "adapts" to the driving style of a particular driver, spinning the engine and shifting gears so that the driver gets the desired result.

If you drive smoothly, the automatic transmission will upshift as quickly as possible, shifting will occur on low revs significantly saves fuel. If you constantly actively press the gas pedal, the system will stay in one gear longer and spin the internal combustion engine, allowing you to achieve active acceleration. The adjustable way to control the automatic transmission allows you to use different kinds modes: sport mode, economy mode, winter mode etc.

Consider the main advantages of automatic transmission:

lack of a clutch pedal, comfort and safety when driving (mainly for beginners);
with proper maintenance, the unit has a long resource;
Automatic transmission saves the engine, allowing you to avoid a number of errors;
gears switch smoothly and without jerks;
the car does not roll back when starting on a hill;

The disadvantages of automatic transmission should also be highlighted:

in cold weather, more time is spent on warming up the car and gearbox, difficulties may arise when starting;
a large amount of oil in the transmission;
slippage, high loads are prohibited;
expensive service and regular replacement oils;
reduced efficiency due to losses in the gas turbine engine;
increased fuel consumption;

Even taking into account the disadvantages, such an automatic machine is in great demand, as it greatly simplifies driving, increases safety and provides necessary comfort. Also, automatic transmission, subject to timely and quality service has a fairly large resource (at least 250 thousand km.).

Robotic gearbox with one and two clutches

Manual transmission is the result of the desire of engineers to combine all the advantages of a manual transmission and an automatic transmission. In fact, the robot box is a mechanic to which servos are attached. These mechanisms independently control the operation of the clutch, as well as select and turn on / off the gears.

In the cabin, as in the case of automatic transmission, there are two pedals (gas and brake), that is, it is easier to control such a machine. At the same time, the box itself has friction clutch, drive and driven shaft (similar to manual transmission), etc.

The main disadvantage can be considered that. Also, the unit shifts gears more slowly, delays are possible. Experts also note that although the box itself lasts a long time, the actuators quickly fail (already by 80-120 thousand km.). However, their cost is quite high.

To summarize, the disadvantages of the "robot" are as follows:

the box is slow, makes jerks when switching;
the car rolls back at the start;
low resource of servomechanisms;

As for the advantages, the advantages of a robotic gearbox:

no clutch pedal, gear shifting is automatic;
lower fuel consumption;
less losses better overclocking and higher efficiency;
the use of a small amount of oil (similarly as in the case of manual transmission).

We also note that a robotic gearbox can be represented by another type. It is about (eg DSG). Such gearboxes are literally a symbiosis of an automatic machine and a robot, capable of providing high smoothness, excellent dynamics and fuel efficiency.

However, the downside is the high cost, the demands on the quality and quantity of oil and the level of service, as well as a noticeably shorter resource compared to automatic transmission (about 150 thousand km.). Again, clutch units, servomechanisms, and also (an analogue of a valve body in an automatic machine with a torque converter) are problematic.

Stepless CVT

The CVT variator is a competitor for all other automatic transmissions (both robotic and automatic). In its structure, such an “automatic machine” is very different from its analogues. Often, the clutch of a CVT gearbox is represented by a torque converter (similar to automatic transmission), but the CVT box itself has a number of design features.

The variator consists of two shafts (driven and driven), pulleys are located on them, which can constantly change their diameter. A variator belt is stretched between the belts. During the start of the car, the drive pulley is large in diameter, and the driven pulley, on the contrary, is smaller.

After sufficient acceleration, the driving pulley gradually decreases, changing the diameter, at which point the driven pulley increases in size. If we compare the “automatic” automatic transmission and the “variator”, then the coefficient useful action significantly higher in the "variator" due to a more rigid connection.

With the help of the most rational and smooth change in the diameter of the pulleys, the driver does not feel the transition from stage to stage, which eliminates shocks, jerks, delays. Power is transferred to the wheels constantly, without interruption. Even when the gas pedal is released, the pace and smoothness of the ride will be maintained after active acceleration.

Differences between the robot box and automatic transmission: what to pay attention to. How to distinguish a robot from an automaton (visually, in motion). Recommendations.

Automatic transmission AT or robotic automatic transmission AMT: which gearbox is better, the features of the "automatic" and "robot". Recommendations.

The mechanical transmission of a car is designed to change the torque and transfer it from the engine to the wheels. It disconnects the engine from the drive wheels of the machine. Let's explain what a manual gearbox consists of - how it works.

The mechanical "box" consists of

crankcase;
primary, secondary and intermediate shafts with gears;
additional shaft and gear reversing;
synchronizers;
gear shift mechanism with locking and blocking devices;
shift lever.

Scheme of work: 1 - input shaft; 2 - switching lever; 3 - switching mechanism; 4 - output shaft; 5 - drain plug; 6 - intermediate shaft; 7 - crankcase.
The crankcase contains the main parts of the transmission. It is attached to the clutch housing, which is attached to the engine. Because during operation, the gears are tested heavy loads they should be well lubricated. Therefore, the crankcase is half its volume filled with gear oil.

The shafts rotate in bearings mounted in the crankcase. They have sets of gears with different number teeth.

Synchronizers are necessary for smooth, silent and shockless gear shifting by equalizing the angular velocities of rotating gears.

Switch mechanism serves to change gears in the box and is controlled by the driver using a lever from the passenger compartment. At the same time, the locking device does not allow two gears to be switched on simultaneously, and the blocking device keeps them from being switched off spontaneously.

gearbox requirements

Ensuring the best traction and fuel-economic properties
high efficiency
ease of control
Shockless switching and quiet operation
the impossibility of simultaneously engaging two gears or reverse when moving forward
reliable retention of gears in the engaged position
simplicity of design and small cost, small size and weight
ease of maintenance and repair

best mode

dimensions

Ease of control depends on the method of gear shifting and the type of drive. Gears are shifted using moving gears, gear couplings, synchronizers, friction or electromagnetic devices. For shockless switching, synchronizers are installed, which complicate the design, and also increase the size and weight of the transmission. That's why most widespread received those in which top gears they are switched by synchronizers, and the lower ones by gear couplings.

How do gears work?

a) Gear ratio of one pair of gears
Take two gears and count the number of teeth. The first gear has 20 teeth, and the second 40. So with two revolutions of the first gear, the second will make only one revolution ( gear ratio equals 2).

b) Gear ratio of two gears
On the image b) the first gear (“A”) has 20 teeth, the second (“B”) has 40, the third (“C”) has 20, the fourth (“G”) has 40. Further, simple arithmetic. The input shaft and gear "A" rotate at a speed of 2000 rpm. Gear "B" rotates 2 times slower, i.e. it has 1000 rpm, and since gears "B" and "C" are fixed on the same shaft, then the third gear makes 1000 rpm. Then gear "G" will rotate even 2 times slower - 500 rpm. From the engine to the input shaft comes - 2000 rpm, and comes out - 500 rpm. On the intermediate shaft at this time - 1000 rpm.

IN this example the gear ratio of the first pair of gears is two, the second pair of gears is also two. The total gear ratio of this scheme is 2x2=4. That is, the number of revolutions on the secondary shaft decreases by 4 times, compared with the primary. Please note that if we disengage gears "B" and "G", then the secondary shaft will not rotate. At the same time, the transmission of torque to the driving wheels of the car is also stopped, which corresponds to a neutral gear.

Reverse gear, i.e. rotation of the output shaft in the opposite direction, is provided by an additional, fourth shaft with a reverse gear. An additional shaft is needed to get odd number pairs of gears, then the torque changes direction:

Torque transmission scheme when reverse gear is engaged: 1 - input shaft; 2 - gear input shaft; 3 - intermediate shaft; 4 - gear and reverse gear shaft; 5 - secondary shaft.

gear ratios

gear ratio

Transfers	VAZ 2105	VAZ 2109
I	3,67	3,636
II	2,10	1,95
III	1,36	1,357
IV	1,00	0,941
V	0,82	0,784
R(Reverse)	3,53	3,53

straight

First and reverse gear are the most “strong”. It is not difficult for the engine to turn the wheels, but the car in this case moves slowly. And when driving uphill in the "nimble" fifth and fourth gears, the motor does not have enough strength. Therefore, you have to switch to lower, but "strong" gears.

First gear is required to start moving so that the engine can move a heavy machine. Further, by increasing the speed and making some margin of inertia, you can switch to the second gear, more "weak", but more "fast", then to the third and so on. The usual driving mode - in fourth (in the city) or fifth (on the highway) - they are the fastest and most economical.

What are the faults?

The shift lever shifts in a calm, smooth motion, with micro-pauses in the neutral position for the synchronizers to work, protecting the gears from breakage. With proper handling and periodic oil changes in the "box", it will not break until the end of its service life.

Noise during operation, which depends mainly on the type of gears installed, is significantly reduced when replacing spur gears with helical gears. Correct work also depends on the service on time.

The gearbox in a car is designed to transmit engine torque to the drive wheels, as well as to change traction. power unit, depending on the operating conditions of the machine. Since the progress of the automotive industry does not stand still, but steps forward, the improvement and change in car gearboxes is gradually taking place.

To date, the following types of gearboxes are distinguished:

Mechanical (manual transmission)
Automatic (automatic transmission)
Robotic (RKPP)
CVT (CVT)

The first transmission, a manual transmission, was created over a hundred years ago, it is ideal for the driver who wants to feel the full power of the engine of his iron horse. Cars with manual transmission are most often used in street racing competitions, it is there that the pilot needs a timely change in engine torque. Also, cars equipped with a manual transmission are used for off-road operation, in various competitions and shows. A car with a manual transmission is convenient in that the driver independently controls the torque and acceleration dynamics.

Advantages of a manual transmission (Mechanics):

Relatively light weight
No additional cooling required
small cost
High efficiency
Ability to tow another vehicle
Ability to start the car from the "pusher"

Significant disadvantages of manual transmission include the following points:

Tedious gear shifting
The need for operating experience ( smooth switching gears)
Long shift time

It should be noted that for normal operation A manual transmission needs a clutch and, accordingly, a third pedal in the car. The clutch is an additional node that is responsible for the smoothness of the gear shift. According to the structure, manual transmissions are divided into two types: three-shaft and two-shaft gearbox. The three-shaft consists of an intermediate, driving and driven shaft, in a two-shaft there is no intermediate shaft.

Despite all the disadvantages of manual transmission, it is quite often used in the creation of cars, for example, in Russia, in America, oddly enough, consumers prefer cars with automatic transmissions.

Robotic gearbox RKPP (Robot)

It would seem that the name of the RKPP is more suitable for the category automatic boxes gear, but no. Manual transmission can be attributed to mechanical boxes. A robotic gearbox was assembled according to the principle of mechanics, but the main difference from it is gear shifting carried out by electronics. talking plain language, manual transmission slightly modified manual transmission.

Unfortunately, the operation of the manual transmission cannot be called good; this type of gearbox is installed on cheap car models. A robotic box, like a mechanical one, consists of a unit with shafts and gears and a microprocessor that controls external sensors.

Advantages of a robotic gearbox:

Facilitates the process of driving a vehicle
economy
Ease of use
Low cost of the mechanism and components

Along with a small number of positive aspects, the manual transmission has a significant negative: in the process of gear shifting, the box itself “thinks” and the gear changes are jerky, which in turn affects the engine in a bad way. When operating a car with a robotic box, there may be a slight rollback at start.

It is believed that for robotic boxes shifting is worth the future, given their huge resource and relatively low cost, companies such as Ford, Mitsubishi and BMW are betting on the improvement of just this type of gearbox.

Automatic transmissions (Automatic)

The automatic transmission is special unit transmission, which serves to transmit torque from the engine to the wheels of the car without the participation of the driver. Automatic transmissions are widely used in the global automotive industry; cars equipped with this type of gearbox are preferred by people of all countries and ages.

Automatic transmissions differ in the number of gears, in the way they are shifted and in the type of clutch, this is the only type of gearbox today that can have up to 8 gears.

The automatic transmission includes:

Planetary gear with gears and satellites
torque converter
Hydraulic system

The gearbox is the main body of the automatic transmission, the torque converter is responsible for converting torque, and the hydraulic system is responsible for controlling planetary gear. For the normal operation of an automatic transmission, it uses a special gear oil that lubricates the main components of the box. The brand of oil should be indicated on the automatic transmission dipstick.

This type The gearbox has several modes: sports, classic and winter, which is quite convenient when the car is operating in certain conditions, and also has the feature of manual shifting.

The advantages of a car with an automatic transmission are as follows:

Ease of management. There is no need to think about which gear to turn on, you can only focus on movement. It is this gearbox that is suitable for novice drivers and women.
Gentle operation of the engine. Due to the torque converter, the automatic transmission itself selects the mode at the start of movement, the absence of jerks when switching.
Possibility to increase the number of gears

Disadvantages of operating a car with automatic transmission:

Increased fuel consumption
Big weight
High cost of maintenance and components
Loss in dynamics and speed compared to manual transmission
Inability to control during the demolition / skidding of the car
Inability to tow another vehicle
When a car with automatic transmission gets stuck in mud and snow, it cannot be “rocked”

CVT gearbox (CVT)

Another gearbox, which represents the types of automatic gearboxes, is a CVT. The variator is the same machine, only stepless. Its task is the same - the transmission of torque from the power unit to the drive wheels.

The variator includes: a differential that is responsible for the distribution of torque, a torque converter that converts gears, planetary gear, which in turn ensures the rotation of the secondary shaft and the control unit responsible for controlling the electronics.

Popular types of variators - belt driven, their name CVT variator, clinomeric and torus variators are less common. The variator is the only type of automatic transmission that shifts without the characteristic "growl" of the motor.

And yet, in order to choose a car with suitable box gears, you need to determine for yourself what you want to get in the end: dynamics and speed, efficiency, ease of driving or low cost of a car. After all priorities are set, you can do right choice in favor of one or another transmission unit.

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

Let's start with the fact that this type of gearbox is called mechanical due to the fact that such a unit involves manual switching gears. 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 most low step (downshift) has the largest gear ratio, and the highest stage ( overdrive) 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.) Note that the vast majority of cars today are equipped with five speed box gears, manual transmissions of 6 or more steps are less common, and the previously quite common 4-speed manual gearboxes 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;

For vehicles with rear wheel drive a three-shaft manual gearbox is usually installed, 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. Specified constituent elements 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 presence 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 in general terms Let's take a look at how it works. 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. The synchronizer will then align angular speeds desired gear and 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 provides reverse gear Checkpoint. 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 the three-shaft gearbox consists of, let's move on to two-shaft boxes. This type The 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 box crankcase is 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 to reduce the size of the checkpoint, as well as increase the number of gears, in modern boxes often, instead of one driven shaft, 2 or even 3 shafts can be installed.

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 switching mechanism itself shaft box has a lever that is connected by cables to the selector lever and the gearshift 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 different types have additional locking devices that prevent the inclusion of two gears at the same time or an unexpected disengagement of the gear.