When applying a car with a manual transmission, the motorist must constantly use the PPC lever to maintain the required speed. He needs to monitor the speed of the car and the load of the motor all the time. The automatic transmission eliminates the need for the permanent use of the switching lever. The gear shift occurs automatically, depending on the speed of moving the car, the load of the motor and the desires of the driver.

Device automatic

The automatic transmission consists of such elements:

1. The hydrotransformer - in fact, in everything corresponds to the adhesion in the manual transmission, but does not need personal control from the motorist.
   
2. The planetary series is designed to change the gear ratio when switching transmissions to the automatic transmission and corresponds to the gearbox gearbox.
   
3. Rear friction, brake tape, front friction - elements with which the gear shift is performed.
   
4. Control system. This node consists of a gear pump, a valve box and an oil separator.
   

The torque converter is designed to transmit torque from the "engine" to the automatic transmission components. It is mounted in an intermediate casing, between the checkpoint and the "engine", and performs the option of ordinary clutch. When working, this node, which is filled with a transmission fluid, performs speeds at high speed and carry heavy loads.

It is capable of not only to transmit a torque, smoothing and absorbing the "engine" vibrations, but also to launch an oil pump that is located in the PPC housing. The oil pump fills the hydrotransformer with oil fluid and forms in the control system and control system.

Therefore, it is mistaken that the vehicle with automatic transmission can be coordinated without the use of the starter. The automatic transmission pump receives energy only from the motor, and if the "engine" does not work, the pressure in the control system and control is not formed, no matter how the ride mode selection lever was not located. Accordingly, the compulsory rotation of the cardan shaft is not able to force the motor to rotate, and the gearbox is to work.

Planetary series. Automatic transmissions, in contrast to the manual transmission, which use the gears and parallel shafts with each other, are used by planetary transmissions.

In the CPT housing there are several planetary mechanisms that provide the required gear ratios. The transmission of torque through the planetary mechanisms from the "engine" to the wheels is due to the differential, planetary disks and other devices. Managing these devices is made by means of control and control using a transmission fluid.

The valve box is the system of channels with plungers and valves that perform control and control options. Such a device converts the degree of presses on the gas pedal, the load "engine" and the speed of the car into hydraulic signals. Due to the chronological inclusion and release of friction blocks from the working state, based on the data of the signals, the transmission relations in the checkpoint occurs.

Brake tape - device used to block the components of the planetary row.

Principle of operation of automatic transmission

Automatic boxes are divided into two types. The difference is based on monitoring and management management systems. For the first species, it is characteristic that the control and control options are performed using a special hydraulic device, and for the second type - an electronic device. Composite parts of the automatic transmission of both types are actually the same.

There are some differences in the device and layout of the automatic transmission of rear-wheel drive and front-wheel drive transport. For automatic transmission machines, automatic transmission machines are more compact and distinguished by the presence inside the body of the main transmission separation - differential.

The principle of all automatic transmission is the same. To fulfill its functions and ensuring movement, the automatic transmission should be equipped with such nodes - a torque converter, a control and control unit, a movement mode selection device.

Advantages of automatic transmission

Compared from the manual transmission, the automatic transmission has such advantages:

1. The ability to manually and automatically switch speeds.
   
2. Protection of the motor and the chassis of the vehicle from overloads.
3. Increasing the comfort of driving vehicle through the liberation of the motorist.
   
4. Automatic and smooth switching, taking into account the load of the motor, speed of movement and the degree of pressing the gas pedal.

Disadvantages of automatic transmission

1. Expensive maintenance and repair.
   
2. Large weight of the unit in comparison with the manual transmission.
3. The relatively low pickup vehicle (as a rule, is characteristic of hydromechanical automatic gearboxes).
4. The impossibility of towing a vehicle on a rigid or flexible coupling (only with a tow truck).
   
5. Compared to the "mechanics", a higher fuel consumption (characteristic of a variator, robotic and hydromechanical gearboxes).
6. Small in comparison with the MCPP operation resource to overhaul (200,000 mileage kilometers maximum).
7. Lack of braking by the engine in Drive mode (this type of braking requires a transition to a reduced transmission mode).
   

Professional tips that choose a mechanic or machine

To date, in many respects, the most practical mechanical transmission is. However, technical progress moves forward and modern automatic transmission becomes more and more durable and reliable, and what is important - economical. The type of transmission with the presence of two clips is already "able" to spend less fuel than standard mechanical gearbox. However, the complexity of the design and the high cost of repairing data transmissions does not speak in favor of the automatic transmission.