Automatic transmission. How does an automatic transmission (automatic transmission) work? Principle of operation of automatic transmission

October 23, 2016.

Automatic car gearbox is designed to transmit engine power to wheels. It sets exactly the transmission that is best suited for the current speed of movement. Automatic transmission eliminates the driver from the need to switch the velocity manually. The computer of the car using the sensors determines which moment the speed must be switched and sends a signal to in electronic format on switching on or off transmission.

The main elements of the automatic transmission

The mechanism of the automatic transmission of the car is a system of levers and gear transmitting power to drive wheels, allowing the engine to work most effectively.

A box in an aluminum casing, called the crankcase. It contains the main components. automatic transmission:

The hydrotransformer performing the role of clutch, but not requiring direct control from the driver.
Planetary series, changing gear ratio when switching.
Rear, front friction, brake tape, directly carrying out shifting.
Control device.

How does the hydrotransformer work?

The torque converter consists of the following main elements:

pump or pumping wheel;
turbine wheel;
lock plates;
stator;
overrogging coupling.

To understand how it works automatic box Transmissions, you need to generally represent its device. So, the pump mechanical connection is associated with the engine. The turbine wheel is connected to the PPC shaft using the slots. When the pump wheel is rotated when the engine is running, an oil flow is created, which rotates the turbine wheel of the torque converter.

In this case, the torque converter performs the role of ordinary hydromeflip, by means of a liquid only passing the torque from the engine to the shaft. With an increase in the engine speed, there is no significant increase in torque.

To convert torque, the circuit of the automatic box includes a stator. The principle of work is that it redirects the oil flow back to the impeller's impeller, causing it to quickly rotate, increasing the torque. The speed of rotation of the turbine wheel with respect to the pump is less, the greater the residual energy is transmitted by the stator by returning the oil to the pump. Accordingly, the torque increases.

Basics of the work of the turbine and pump automatic transmission

Turbine always rotates slower than the pump. The maximum ratio of the speed of rotation of the pump and the turbine is achieved with a fixed car, decreasing with increasing speed vehicle (TC). The connection of the stator with the hydrotransformer is carried out through the overtook coupling that can rotate only in one direction.

The turbines and stator blades are of particular shape, due to which the flow of oil is redirected to the opposite side of the stator blades. At the same time, the stator jars and, remaining still, it transmits the highest energy of oil to the pump inlet.

Due to this mode of operation of the hydrotransformer, the maximum torque transmission is ensured. It increases almost three times when driving a car from the spot.

When accelerating the vehicle, the turbine relative to the pump slippers less than the occurrence of the moment when the stator wheel is picked up by the flow of oil, starting to rotate in the direction of the free move of the overtook coupling. The device at the same time starts to work as an ordinary hydromefta, does not increase the torque. In this mode, the CPD of the hydrotransformer does not exceed 85%. Such a mode of operation is accompanied by the release of excess heat and an increase in fuel consumption.

Purpose of the blocking plate

This disadvantage is eliminated using a special device - blocking plates. Despite the mechanical connection with the turbine, it is structurally performed so that it can move to the right and left. This device is turned on to work when the high speed car is reached. By command, the control unit of the oil flow changes in such a way that it presses the locking plate to the torque converter body on the right.

In this case, the turbine and pump are connected to each other mechanically. To increase clutch on inner side The housing of the hydrotransformer is applied a special friction layer. Thus, the engine is associated with the output shaft of the automatic box. Naturally, such a blocking immediately turns off even with a slight braking of the car.

Above, only one of the methods of blocking the torque converter was described. However, any other way pursues the same goal - to prevent the turbine slipping towards the pump wheel. Usually the described action mode in various sources is called Lock-Up.

The operation of the hydrotransformer for dummies will be easier to understand if instead of a turbine and pump present two simple fans, one of which is running from the network, and the other rotates due to the air flow fan being created by the first fan. Only instead of air there is oil here, and the blades of the first fan (pump in the case of automatic transmission) are driven out of electricity, but due to the mechanical connection with the engine of the car engine.

Planetary rows

The torque converter can increase the torque, but only to a certain limit. Automatic transmission device for a more significant increase in torque, for example, when overcoming lifts, as well as for movement reverse Provides planetary rows. The planetary transmission also provides even switching speeds when moving without loss of motor power. Thanks to her, switching occurs without jolts, which occurs when working in the usual transmission.

The planetary series includes the following elements:

sunny gear;
satellites;
epicycle;
drove.

The planetary row is called due to the fact that friction wheels rotating simultaneously around their axes and moving along with these axes are very similar to the planets of the solar system. It depends on their mutual position, what is currently being turned on.

How to switch transmissions to automatic transmission?

Switching gear or change in the planetary gearbox of the gear ratio is carried out by blocking and unlocking the elements of the planetary row through brake tapes and friction. In the hydraulic system of the automatic transmission of the car directly shifting the gear is carried out by valve. The three-speed box has two such valves, one of which switches from the first transmission to the second, the other - from the second to the third. The four-speed box has three valves.

Other types of automatic transmission

In addition to the considered hydraulic transmission, other types of automatic boxes are widespread today:

Variator automatic transmission. In this type of transmission of a fixed gear ratio for transmissions does not exist. Therefore, such automatic transmission is called a stepless. The principle of operation is that, unlike other "automata", it uses the engine power more effectively. As a consequence, cars equipped with this type of transmission are more economical and comfortable.
Robotic checkpoint. Automatic such a box can be called conditionally, since it is essentially the usual "mechanics", where the function of the clutch pedal is assigned to the electronic unit. Cars with what boxes are also rather economical, but less comfortable, since often switching gears in automatic mode is accompanied by jerks.

Thus, in addition to the most common hydraulic automatic transmission, there are several more types of automatic boxes that differ in their design. They are distinguished by price, efficiency, comfort of car management. The general is that the driver is dispossed from the need. independent choice and switching gear.

Driving a car equipped with an automatic transmission is quite simple, difficulties arise from newbies who have not become familiar with the principle of operation of automatic transmission and with its constructive features.

Did you manage the car with the manual transmission and do not feel about "teapot"? Then at the first time of driving automatic transmission, watch the position of the left leg. The acquired habit of pressing the clutch pedal, which is absent on the car, equipped with automatic transmission can interfere with the ride. Obviously: Before controlling the machine equipped with a selector, learn how to use only one foot - quickly move the right leg with the "Gas" pedal on the "brake", not remembering about the grip.

The speed switching lever in cars equipped with automatic transmission is called a selector, it is additionally equipped with an unlock button that prevents incorrect gear shift. The main advantage of the specified type of boxes is the possibility of selection of electronics of the gear ratio corresponding to the driving conditions, without the driver's participation. There is no need to study smoothly switch the transfer: "smart" box copes with this task yourself.

Driving a car equipped with an automatic transmission begins with the study of the main modes of the unit operating the corresponding notation:

"P" is parking, used to start a motor. The selector switches to this position, provided that the TC is completely stopped or using the handbrake. Some car manufacturers with automatic boxes in the instruction manual of the machine indicate the need to use manual brakes During the application of the Parking position.
"D" - movement forward, allows the car to move forward. The extent of pressing the pedal of "gas" and the conditions of movement of the transmission vehicle will be used automatically. Being in the specified mode, the car standing on the inclined surface will not roll back if the angle of tilt the surface is not too steep.
"R" - reverse, allows the car to move back. This position is turned on after a complete stop of the car, plus when the "brake" pedal is squeezed.
"N" is a neutral, applied to warming up the motor in the cold season, it is not recommended to switch the selector to the specified position during the movement of the machine. Provides idle work power aggregate Without transmission torque on the wheels.
"D2" (or S) - reduction of transmission, is used on descents, lines. Stop the machine in this mode will be more efficient than when "D". The box will use only two programs - the first and second.
"D1" (or L) is the subsequent range of reduction of transmission, is used in the icing of roads, mountain serpentine, in some cases can be used to braking the engine. In this mode, the car will always move on the first gear.

Switching the selector from the position "D" in the position "D3" (D2), "D2" (D1) is performed when the machine is moving. Advanced automatic gearboxes have additional overclocking modes:

economic - "E";
normal - "N";
sports - "s".

Practical lessons

Install the selector to the required mode by following the following steps:

Run the engine (switch the lever will be obtained only when the engine is installed).
Sick the "brake pedal".
Click the desired mode button located on the selector (if there is a need for this).
Select the position corresponding to the necessary direction of movement of the machine: "D" - the vehicle will go forward, "n" - neutral, the car will stand still, or rolled under the slope, "R" will go back. When you turn on the selected drive driver, the car will not start moving, and when to release the "brake" pedal - the car will go. Take into account this nuance, do not remove the leg with the "brake" ahead of time to avoid accidents.

Automatic boxes recognize the driver's commands by pressing the "Gas" pedal: smooth overclocking, gradual speed switching is provided by pressing with a small force. Intensive acceleration required during overtaking is achieved by the release of the "gas" pedal to the floor, while the automatic transmission will first turn on the transmission below, then the car will start accelerate. Take into account: from the moment of squeezing the "gas" pedal until the vehicle is overclocked, a slight delay occurs, about one second, this time is irrevotably with unhurried ride, and in overall conditions can be fatal.

Deciding to stop the movement of the car, press the "brake pedal". With a short stop, on the traffic light, do not translate the selector from the position "D" - extend the resource of the internal mechanisms of automatic transmission.

Keep the brake pedal pressed after stopping the machine in situations:

Long stops (corks), the brake pedal will allow the Motor to relax, will not be in vain to burn fuel, use the position "N".
The car stands on the slope, the selector is not translated into the position "P".

The above instruction for "kettles" will allow you to drive a car with a box. Note: It is better to learn right away proper drivingIn order not to harm the automatic transmission. Fix the harmful way to control the vehicle is difficult.

Additional modes

Additional modes of boxes automatic include:

Winter mode, has the designation "*", "W", "Snow", "HOLD", "WINTER". According to it, the slip is excluded during the switching speed and at the beginning of the vehicle movement. The movement of the machine from the second transfer is made. Switching to other transmissions occurs with smaller drive turnover - this makes it possible to eliminate the differences in the operation of the box during acceleration, reduces the likelihood of car drift. Experts clarify: do not use the specified mode in the summer - you can get overheating box due to maximum load on the unit.
The positions of the position "D" limit the acceleration of more than a certain range of transmissions:

"S" or "s" - ensuring the inclusion of the transfer not higher than the third. These positions are used in areas of road requiring increased attention from the driver. Carrying out driving, use the "s" mode, while watching the testimony of the tachometer, its arrow should not fall into the red zone.
"2" - restriction of the inclusion of gears not higher than the second, the movement of the car occurs at no more than 80 km / h. Applied on steep slopes, slippery roads.
"1", "L" - used for heavy Conditions Machine operation: Riding off-road, steep slopes. Only transmission, speed not more than 40 km / h.

Additional operating modes of boxes automaton allow you to control the machine under adverse conditions. Consider: the accidental inclusion of subdirements "1", "2" at high speed will lead to a sharp slowdown of the auto movement, provokes a vehicle.

Automatic driver can control the box, the following recommendations will be allowed to extend the ACAP resource:

You can not give heavy loads on an immentable box. Transmission oil warms slower motor fluid. When managing the machine with the specified type of box, drive a few kilometers at low speed.
Avoid slipping wheels: Do not press sharply on "gas" if the road coating is inhomogeneous.
Try not to tow trailers, other cars.
Refuse to turn on neutral when moving a car.

Proper operation of the automatic box allows you to enjoy driving and prevents the premature breakdown of the unit, allowing the mechanism to work normally.

How to check the oil in the gearbox Box automatic when switching transmission pulls the machine

Appeared in the 1940s. As you know, the presence of an automatic transmission significantly facilitates the process of operation of the vehicle, also reduces the load on the driver, safety increases, etc.

Note that under the "classic" automatic box should be understood as a hydromechanical transmission (hydromechanical machine). Next, we look at the device box - automatic, constructive features, as well as the advantages and disadvantages of the PPC of this type.

Read in this article

Car with automatic transmission: advantages and disadvantages

Let's start with the advantages. Installing an automatic transmission allows the driver during a ride not to use the gear lever, the foot is not involved for a permanent clutch pressing when switching to an increased or reduced stage.

In other words, the change in speed occurs automatically, that is, the box itself takes into account the load on, the speed of movement of the vehicle, the position of the gas pedal, the desire of the driver himself sharply accelerate or move smoothly, etc.

As a result, the comfort of driving the car with automatic transmission increases significantly, the transmissions switch automatically, gently and smoothly, the engine, the elements of the transmission and the chassis are protected from heavy loads. Moreover, many automatic boxes provide for the possibility of not only automatic, but also manual switching Transmissions.

As for the minuses, they are also available. First of all, constructively automatic automatic transmission is a complex and expensive unit, differs by reduced maintainability and resource compared to. The car with this type of gearboxes consumes more fuel, the automatic box gives less on the wheels, since the CPD of the box automatic is slightly reduced.

Also, the presence in the car automatic transmission imposes on the driver certain limitations. For example, the automatic box must be warmed before the trip, it is advisable to avoid constant sharp starts and too intense braking.

On the machine with an automatic box, it is impossible to bounce, it is not allowed to tug a car with a box of a machine at high speed over long distances without hanging the driving wheels, etc. We also add that such a box is more difficult and more expensive.

Box automatic: device

So, even taking into account certain disadvantages, automatic hydro mechanical box For a number of reasons, for a long time remained the most common solution to change the torque among other types of automatic transmissions.

First of all, even taking into account the fact that the resource and productivity of such boxes is lower than that of the "mechanics", the hydromechanical transmission is quite reliable and durable. Now let's look at the automatic transmission device.

The automatic transmission consists of the following basic elements:

Hydrotransformer. The device performs a clutch function by analogy with the manual transmission, however, the driver's participation is required to transition to one transmission;
The planetary series, which is similar to the gear unit in manual "mechanics" and allows you to change the transfer ratio during transmissions;
Brake tape and friction (front, rear friction) allow smoothly and timely switching transmissions;
Office automatic transmission. This node includes the oil collector (pallet of the box), a gear pump, as well as a valve box;

Control automatic control is performed using a selector. As a rule, the automatic transmission has the following main modes:

R - Parking mode;
R - Movement with reversal;
N mode n-substial transmission;
Mode D-forward with automatic gear shift;

Other modes can also be available. For example, L2 mode means that there will be only the first and second transmission when moving forward, L1 mode indicates only the first transmission mode, s mode should be understood as a sporty, there can be various "winter" modes, etc.

Additionally, imitation of manual automatic transmission can be implemented, that is, the driver can increase or lower the transmissions on its own (manually). We also add that the automatic box also often has a Kick-Down mode (kick-down), which allows the car sharply accelerate with such a need.

The "kick-down" mode is triggered when the driver presses sharply on gas, after which the box quickly goes to reduced transmissions, thereby allowing to unwind the engine to high revs.

As can be seen, the box - the machine actually consists of a torque converter, a manual transmission, as well as control systems, which in the aggregate and forms a hydromechanical box. Let's look at its device.

Principle of operation and construction of the hydrotransformer

The torque converter is necessary in order to transmit and change the torque from the engine to the box. Also, the torque converter reduces vibrations. The device of the hydrotransformer assumes the presence of a pumping, turbine and reactor wheel.

Also in the torque converter there is a blocking clutch and a clutch of the free stroke. The hydrotransformer (GDT, often in everyday life is called "Bublik") is part of the automatic transmission, but it has a separate case from a durable material filled with working fluid.

The pumping wheel of GDT is attached to the engine crankshaft. The turbine wheel is associated with the gearbox itself. There is also a reactor wheel between the turbine and pumping wheel, which is fixed. Each of the wheels of the hydrotransformer has blades that differ in their form. Between the blades, the channels are implemented through which the transmission fluid passes ( transmission oil, ATF, from English. Automatic Transmissions Fluid).

The blocking clutch is necessary to lock the torque converter in some modes of operation. The overtaking coupling or a free move coupling is responsible for ensuring that the rigidly fixed reactor wheel is able to rotate in the opposite direction.

Now let's look at how the hydrotransformer works. Its work is based on a closed cycle and is that the transmission fluid is supplied to a turbine wheel from the pumping wheel. Then the fluid flow enters the reactor wheel.

Reactor blades are designed to enhance the flow rate aTF fluids. The accelerated flow is redirected to the pumping wheel, forcing it to rotate with a greater speed result - an increase in the torque value. It is worth adding that the maximum moment is achieved when the torque converter is rotated at the lowest speed.

When the engine crankshaft is spinning, the angular velocity of the pumping and turbine wheel is aligned, while the flow transmission fluid Changes the direction. Then the clutch of the free move occurs, after which the reactor wheel begins to rotate. In this case, the torque converter switches to the hydromefta mode, that is, only torque is transmitted.

A further set of speed leads to a locking of the torque converter (the locking clutch is closed), resulting in a direct transmission of torque from the motor to the box. In this case, the GDT blocking occurs on different transmissions.

It should be noted that in modern automatic transmissions, the mode of operation is implemented with slipping the clutch of the torque converter blocking. This mode eliminates the full locking of the torque converter.

This mode of operation is possible to be implemented if the conditions are appropriate, that is, when the load and speed are suitable for activation it. The main task of the clutch slippage becomes more intensive acceleration of the car, reducing the consumption of combustible, softer and smooth transmission.

What is the automatic transmission: how the mechanical part of the box is arranged and works

The automatic transmission (automatic transmission) itself, as well as mechanical, stepwise changes the torque when moving the machine forward, and also allows you to move back when the reverse transmission is turned on.

At the same time, the automatic boxes typically use the planetary gearbox. This solution is compact, allows you to implement efficient operation. For example, the MCPP often has two planetary gearboxes that are connected consistently and work together.

Combining gearboxes makes it possible to get the required number of steps (speeds) in the box. Simple automatic transmissions have four steps (four-stage automatic), while modern solutions can have six, seven, eight, or even nine steps.

The planetary gearbox includes several consecutive planetary gears. Such transfers form a planetary series. Each of the planetary gear includes:

sunny gear;
satellites;
corona gear;
drove;

The ability to change the torque and transmit rotation becomes available when the planetary row elements are blocked. One or two elements (solar or corona gear, drove) can be blocked.

If the crown gear is blocked, then the gear ratio increases. If the solar gear is fixed, then the gear ratio will be reduced. The blocked lead means that the direction of rotation is shown.

For the blocking itself, friction clutches (frictional) are responding, as well as the brake. The coupling blocks the parts of the planetary row among themselves, while the brake holds the desired elements of the gearbox due to the connection with the PPC housing. Depending on the design of one or another automatic transmission, a ribbon or multi-disc brake can be used.

The closure of couplings and brakes occurs due to hydraulic cylinders. Manage such hydraulic cylinders is implemented from a special module (distribution module).

Also in common design An automatic box may be the overtaking clutch, whose task becomes kept drove, which allows you to prevent its rotation in the opposite direction. It turns out, transmission to automatic transmission switches due to frictions and brakes.

Automatic automatic transmission control and principle

As for the principles of operation of the automatic transmission, the box works on a given algorithm for the inclusion and off of friction and brakes. The control system of such inclusions and shutdowns on modern boxes is electronic, that is, the selector (lever), sensors and gearbox have.

The automatic transmission control unit is integrated into and closely connected with the engine control unit. By analogy with the engine, the automatic transmission control unit also interacts with different sensors, which transmits signals to it about the speed of the gearbox, the temperature of the transmission fluid, the position of the gas pedal, the selector installation modes, etc.

The gear of the gearbox produces the processing of the received signals, then sends commands to actuators in the distribution module. As a result, the box determines which transmission to include in certain conditions (increased or reduced).

At the same time there is no clear given algorithm, that is, the transition point to different transmissions "floating" and is determined by the ECU itself with a box. This feature allows the system to work more flexibly.

Hydrock (it is the same hydraulic block, hydrophilt, distribution module) actually manages the transmission aTF liquid, responding to the triggering of friction and brakes in the automatic transmission. This module has electromagnetic valves (solenoids) and special distributors, which are interconnected by narrow channels.

Solenoids are needed to switch gear, as they regulate pressure working fluid in the box. Valve data operation is monitored and regulated by the automatic transmission control unit. The distributors are responsible for choosing operating modes and are activated by lever (selector).

The circulation of the hydraulic fluid in the automatic box corresponds to the pump pump. Pumps are gear and blade, they are activated by the hub of the hydrotransformer. It is important to understand that the pump along with the hydroplated (hydroblock) is the most important details in the design of the hydraulic part of the automatic box.

With the fact that in the process of work, the box has a property to heat up, the automatic transmission often has its own cooling system. At the same time, depending on the design, a separate oil radiator can be present, or a cooler or heat exchanger, which is turned on in.

That in the end

Taking into account the above information it becomes clear that the automatic box is a whole complex of mechanical, hydraulic and electronic devices. In this case, control is carried out both hydraulics and electronic unit.

It should also be noted that on the layout, automatic transmissions may differ for cars with front and rear wheel driveAlthough most component elements The same.

If we talk about the mechanical part of the automatic transmission, the planetary series is used in its device, which is distinguished by this type of boxes from ordinary "mechanics" (in the mechanical gearbox put parallel shafts and the gears attached to them, which are in engaging each other).

As for the hydrotransformer, this device can be considered a separate element of automatic transmission, since GDT is placed between the motor and the box, performing the clutch functions by analogy with the manual transmission.

Also, the hydrotransformer is driven by an oil pump inside the automatic box. The indicated pump creates the operating pressure of the transmission fluid, which, in turn, allows you to implement the control of the box.

Finally, we note that you should not try to start a car with a "automatic" box without starter (with overclocking), as is often practiced on cars with a manual box. The fact is that the ACP pump is activated from the engine.

It turns out that the engine does not work, the pressure of the working transmission fluid in the box will not be. This means that without pressure, it will not be possible to implement the automatic transmission control, and no matter what position the operation mode selection will be in the position. Moreover, an attempt to start a machine with a machine "from the Pull" can lead to serious gearbox breakdowns.

Modes of work

To understand how the automatic box should be operated, you need to deal with what existing modes.

It should be immediately noted that the modes "P", "R", "D" and "N" are mandatory in each box. To select one of the modes, you just need to move the shift lever to the appropriate position. The difference from the manual box is that the movement of the lever occurs on one line.

The mode that the driver selected will be displayed on the control panel. It makes it possible to carefully follow the road and not distracted to look at the lever.

"P" - Parking. Used during long parking. It is with parking that it is advisable to start a car. It is important before turning on this mode to completely stop the machine.
"R" - used to move with reverse. To enable, you need to stop completely.
"N" is a neutral position. When the lever is on the "neutral", the torque is not transmitted to the wheels. It is worth using in a period of minor stops.
"D" - movement. When the selector is in this position, the car goes forward. Shift shift is performed independently. The driver is just taking a gas pedal.

In the car, which installed five - or four-stage box, the selector has several positions for moving forward: "D", "d3", "d2", "d1". These numbers show upper gear.

"D3" - "The first 3 transmissions". It is recommended to use in cases where there is no possibility to move without slowing down.
"D2" - "The first 2 transmissions". Translate the lever into such a position when the speed of movement is less than 50 km / h. Most often used on poor-quality roads.
"D1" ("L") - "Only 1st Transfer". Used in the event that maximum speed is 25 km / h. Translate the lever to a similar position is when the machine is in traffic.
"OD" - "Increased transmission". In such a position should be moved when the speed reaches more than 75 km / h, and leave it when the speed drops below 70 km / h. Increased transmission makes it possible to reduce fuel consumption at the moments of movement in motorways.

Most of the new machines with automatt have several ACAP auxiliary modes. To those can be attributed:

"N" is standard, which is used during a regular ride.
"E" - fuel economy mode. Helps the car to move at such a pace, which significantly reduces fuel consumption.
"S" - Sport. When the driver switches to this mode, it can maximize the power of the motor. Nothing surprising is that fuel consumption in this mode will be high.
"W" - winter. It is used in those moments when you need to start moving from slippery road surface.

Of course, there are drivers who could not get used to the automatic transmission, given all its advantages. To satisfy the needs of these people, the "Titonik" regime was created. In essence, he implies a manual control imitation. On the box, it is implemented in the form of a groove for the selector, and marked with signs plus and minus. Plus makes it possible to increase the transfer, and minus - downgrade, respectively.

Basic operating conditions automatic

In order to start moving by the machine in which the automatic box is installed, the actions should be performed in the following order:

Press the brake pedal.
Selector Move to the "Drive" position.
Remove from the handbrake.
Slowly let go of the brake. The car will start slowly moving.
Press the accelerator pedal.
To reduce speed, you need to throw gas. If you need a quick stop, then you need to use the brake.
To move after a minor stop, you just need to move the foot from the brake, to the accelerator.

The main rule of using automatic transmission is to avoid sharp maneuvers. If you constantly do to them, it will increase the gap between the friction disks, and then in the differential. All this will lead to the fact that the machine will twitch during each transmission switching.

Experienced masters believe that the machine must be given a short-term "rest." This means that the car needs to be able to move a few seconds to idling. It is worth noting that even in a car with a powerful engine, sharp movements will significantly reduce the resource of the box.

In fact, this moment is very important, because most of Such boxes broke in winter. First of all, this is due to a significant drop in temperature and so that the machines are often touched on ice. In order to maximize their car from breakdown, follow the following recommendations:

Before the onset of cold weather, check the quality and level of fluid in the box, and if necessary, replace;
Be sure to warm up the car before starting the movement;
If the car is stuck, do not harm the gas hoping to leave. It is worth trying to reduce the transfer (if there is such an opportunity) or just push;
Before a steep turn, use only reduced transmissions.

What not to do

What you should not do by car with an automatic box:

First of all, you should not heat the box badly if the car did not warm up to required level. Even if the street plus temperature, the first few kilometers, the movement should be smooth and measured.
The automatic transmission "does not like" off-road. Machines with automatic, it is best to travel around the roads with bad coatings. If the "iron horse" is stuck, sometimes it is better to resort to the help of shovel than to put pressure on gas.
It is not recommended to expose the automatic transmission to high loads. If there were plans to tow the trailer, it is better to throw them out of the head.
It is strictly forbidden to start a car with a so-called pusher. Many people violate this ban, but it is worth remembering that it will not pass without a trace for the box.

Of course, it is impossible to forget about certain features of switching between modes:

on the "neutral" one can remain only if the brake is pressed;
on the "neutral", the car is prohibited;
swimming the motor is permitted exclusively in the Parking position;
when the car in motion cannot be transferred to the lever in the parking position and the "movement back".

Summing up, it is worth noting that the automatic box may seem pretty "picky" and having a small resource. In fact, if it is competent to exploit it, it will delight your owner for a very long time.

Video: how to use the automatic transmission

It should be noted that the torque converter is a substitute for the usual clutch with a manual transmission. That is why in a car with a "machine" instead of the usual three pedals there are only pedals of brakes and gas. To move, it is enough to fix the switching lever to "Drive" and press the gas pedal.

What is the most important difference between the automatic transmission from the manual transmission?

In the previous article, we looked at how the mechanical gearbox is arranged and found out that the transmission switching occurs when a certain gear is connected, and there are several sets. The automatic box will use only one set of gears for switching gears in its work, and allows this to make a planetary transmission.

The planetary transmission according to its size is small - as a middle melon, but it is responsible for the transfer of all possible gear ratios, and all other parts in the automatic machine only help her successfully cope with this complex task. Structurally, it includes in its composition the sun gears, followed by satellites and the corona gear. They can be fixed in a certain position, working on the input or output - thereby determined by the gear ratio.

The planetary transmission uses the blocking of some elements and unlocking others to switch gear and consists of only one central shaft, while the manual transmission of the gears and parallel shafts are engaged for this - in this advantage of the planetary transmission and automatic transmission as a whole.

Brake tape and friction

Due to the brake ribbon and climbing, blocking of certain elements of the planetary row can be performed - and this makes it possible to switch different transmissions. The braking tape blocks the elements of the planetary transmission to the ACP body (it is attached to the body), and the friction glasses allow you to block the components of the planetary row among themselves, preventing the rotation of the blocked elements counterclockwise. The braking tape has a rather high holding ability and blocks the elements of the planetary row due to the self-compliance effect.

Hydrotransformer: Durable vibration damper, which devastates severe shoes

The hydrotransformer has a turbine and pump in its design. There is a reactor between these blade machines (it looks like a wheel with shovels), which is the guide device. It can be easily blocked by the overtook clutch or simply rotate, it all depends on the conditions of movement.

The blades of the centrifugal pump are discarded on a turbine wheel, the streams of which, in fact, and transmit the torque from the engine to the automatic transmission. In order for the oil to circulate continuously, special gaps between the turbine and the pump are provided, and their blades are still given a certain geometry. It is exactly the fact that the torque is transmitted by oil streams, explains the absence of a tight touch between the checkpoint itself and the engine (in the mechanics the primary shaft is connected directly to the engine). Thanks to this scheme, it is possible to stop the car without turning off the engine.

However, we said earlier that it is not enough to pass the torque to the drive wheels, it is necessary to change it and qualitatively - a reactor copes with this task. Since it is located between the turbine and pump, its blades are located on the way to return the oil from the turbine into the pump. If the rector is fixed, the oil rate circulating between the wheels increases. And the greater the speed of the circulating oil, the greater the impact it has a turbine on the wheel. The reactor begins to rotate at the moment when the speed of the pump and the turbine turnover is beginning to be compared, thereby reducing the kinetic energy of the working fluid. This mode of operation of the reactor is customary called "hydromefta mode".

Sometimes the speed and torque is simply not needed (let's say you drive in a straight line at a constant speed), then the torque converter is blocked by friction. But as soon as the conditions of movement change (switched from constant speed in a straight line to rise to the mountain), the torque converter immediately turns on to work. With a decrease in the frequency of rotation of the turbine, the reactor will begin to be braked, as a result of which the circulating oil types the speed and automatically increase the torque indicator that is transmitted to the wheels (that is, on the shaft from the turbine). This zoom range is enough to overcome the lift without the need to switch to a lower gear.

How does the transmission turn on?

The gear shift occurs without a power break - one turned off, another turns on the other. The hydraulic pusher is driven by the oil pressure used in the hydrotransformer, after which it presses on the friction. Pressure indicator is controlled by electronics. At this moment, the clutch elements (connected hard with the shaft) are flooded. The shaft stops and the transmission turns on.

When switching the automatic transmission lever to "Drive" mode, the center torque is transmitted to the central shaft. The shaft is connected to the solar gear, while the crown gear is blocked by friction. As soon as the crown gear is unlocked, it will drop its power during rotation, and the transmission will increase. If electronic device The team came to lower the transfer, the shaft is fixed by friction, while the engine rotates the planning series solar gear. At this moment, the crown gear loses its power and the transfer drops.

For a visual demonstration of an automatic transmission device, also offer to watch Toyota video.