The transmission or automatic change system is responsible for changing the gear ratio without the user intervening when the vehicle is moving. In this way, the driver does not need to change manually. In these automatic changes, the demultiplications are obtained by epicycloidal or planetary gears, while in the manuals they are made with the so -called parallel gears.
How do automatic exchange boxes arise?
The first automatic exchange boxes arise in 1940, and their goal was double: increase the number of users who could drive, and expand the manufacturers market. In fact, it was not 100% automatic transmissions, but changed autonomously when the vehicle was already moving. In addition, they worked with a simple hydraulic oil and not with an ATF, which did not develop until years later.
Today, the automatic gearbox is the one that works hydraulically by a fluid coupling or a torque converter and a set of planetarians that provide the necessary multiplication. One of the most important components of automatic transmission is the oil pump, which provides the lubricating fluid flow to all components and gears.
How does an automatic change work?
The differences with respect to a manual change are quite obvious. While in the manual the driver must step on the clutch and move the lever, in the automatic change this operation is performed by the vehicle by means of a switchboard that perceives the pressure of the accelerator or brake pedal, and acts automatically to select the appropriate march.
What elements make up an automatic gearbox?
To make your operation clear, you must know what pieces it is formed:
- Torque converter.
- Planetary gear set.
- Friction material bands to press part of the planetary game.
- Clutch game.
- Hydraulic system
- Oil pump that pressurizes, lubricates and cools.
Types of automatic change boxes
You should also know that there is not a single typology in this case, so we would like to summarize them:
- Torque converter: mounted in the first automatic changes, it is formed by a round housing that consists of two turbines, one connected to the engine and another to the speed box. When the engine rotates, the oil is driven by projecting towards the turbine. The higher the number of revolutions, the more strength the oil will have that will make the turbine turn and the vehicle starts. At present it is one of the most reliable boxes in terms of quality and price, and is used in high displacement vehicles.
- Piloted manual gearbox: it is a mixture between a manual and automatic gearbox, and is called CMP. It incorporates an internal clutch system that automatically operates the march. Although it does not have clutch pedal, it is convenient to lift the accelerator pedal when the change occurs to avoid a sharp gear change. As a result we will obtain an answer very similar to that of manual transmission but without the need to press or change march.
- Exchange box by continuous variator: it is a system similar to the torque converter, but that incorporates a development system formed by two pulleys united by a chain that transmits the power of the engine to the gears of the box. The transmissions are differentiated by the diameter in which the chain moves. Its main advantage is that it barely produces retention, so once launched it is almost no lack of accelerating to maintain speed, which translates into low fuel consumption.
- Double clutch gearbox: composed of two automatic gearboxes in one. The first is responsible for the odd marches and the second of the peers, thus the changes in thousandths of a second, much faster than a driver manually change. When the box gears, the other is already prepared to introduce the following, so that a greater smoothness in driving and an improvement of consumption is achieved.
Maintenance of automatic exchange boxes
It is a fundamental element for the proper functioning of the vehicle to occur, so it needs maintenance, which consists of the replacement of the transmission oil (ATEF) and the filter. This operation must be carried out with a special machine that makes a complete transfusion of the fluid so that the new ATF enters the gearbox fully clean, and must be entrusted only to professionals in the sector.
In Spain, automatic change is not yet imposed as preferred by drivers. The last report by Ford Motor Company tells us that 83% of European drivers prefer a manual change, and in Spain this figure rises to 95%. Therefore, if we have one, we must go to specialists in the sector that guarantee us a correct repair and/or maintenance of the gearbox.
