What is an Automatic Transmission?
Automatic Transmission (or Automatic Transmission System) is the process of transferring the power (generated by the engine) from the engine to the gearbox automatically without any manual gearing or it is defined as automatic shifting of Gear Ratio according to the situation without any human interference.
Automatic Transmission (AT) is also called the Self-Shifting Transmission. Generally, there are two types of transmissions; they are Manual and Automatic Transmissions. In Manual Transmission vehicles, the driver is supposed to change the gear according to the speed he moves but in an Automatic Transmission System, the process will be automatic.
Let us start learning about how does automatic transmission works?
What can we learn from this post?
- Automatic Transmission Gearbox
- Automatic Transmission Parts
- How Does Automatic Transmission Work?
- Automatic Transmission Cars
- Types of Modes in Automatic Transmission System
- Advantages of Automatic Transmission
Automatic Transmission Gearbox:
The process of automation or automatic gearing is done by the special gears called Planetary Gear Train or Epicyclic Gears. It is the type of gear or gear trains that are responsible for the Automatic Transmission System in the vehicles. It can also be called as Automatic Transmission Gears also.
Due to this planetary gear train (or automatic transmission gears), the vehicles can automatically change the Gear Ratio according to the speed of the vehicle or the situation of the vehicle, so there is no necessity of external interference like human power to change the gears.
Automatic Transmission Parts:
As mentioned above, the typical AT Gearing System is because of Planetary Gear Train System; the planetary gear train system consists of a number of components, they are
- Sun gear
- Planet gear
- Ring gear
The Sun Gear, Planet Gear, and Ring gears are mounted one above the other; according to the actuation of the Friction Clutch, the gears will rotate and stop. By the rotation of gears, the transmission of energy from the Engine to the rear wheels can be achieved.
The construction of the Gears can be seen in the above image. The planetary gears are hold by the Carrier and move at the same time with the same ratio.
How Does Automatic Transmission Work?
Focusing on the working of planetary type of Gear Train, Automatic Transmission system consists of Torque Converter that acts like a Clutch; it will connect the Engine and the Planetary Transmission system or Planetary Gear Box. It will Engage and Disengage the input, output shafts according to the requirement. All bands and clutches will be actuated according to the speed of the vehicle that it wants to move.
The speed of the vehicle can be accelerated by the accelerator and the gearing ratio depends upon this Planetary Gear Train System, the reductions or overdrive ratios will be varied by this Gear Train. The Planet Gears will be attached by Carrier so all the three planet gears can rotate at a similar speed or ratio.
The process or the principle sequence of Engaging and Disengaging of Gears according to the speed is controlled by the Internal Programmed device called SPRAG, it is nothing but a Roller Clutch that can be used for routing up-shifts and downshifts.
The Roller Clutch will remove the sensitivity of the time while engaging and disengaging the Gears. The rotation of gears depends upon the speed where sometimes planetary gears will rotate idle, does nothing, and sometimes the Sun gear.
Automatic Transmission Cars:
All Luxury Cars are built with Automatic Transmission System but nowadays some of the Non-Luxury cars are also using this technology for a good performance so, some of the Luxury and Non-Luxury automatic transmission cars or vehicles are as follows:
Luxury Automatic Transmission Cars:
- BMW Cars Mercedes
- Porsche, etc
Non-Luxury Automatic Transmission Cars:
- Hyundai Creta
- Toyota Fortuner.
- Volkswagen Tiguan, etc.
We can find Heavy and Transporting Vehicles with AT, some of the models are
- The new Eicher Pro 3016.
- The Mercedes Vehicles.
- Tata Buses.
Types of Modes in Automatic Transmission System:
The AT vehicles consist of few basic modes on their Gear Rod; they are Drive mode (D) to move the vehicle, Park Mode (P) to park the car steadily at parking, Sport Mode is to move the vehicle fast, Neutral Mode helps to stop and still the vehicle, Reverse Mode to move back.
Advantages of Automatic Transmission:
- Reliable Performance:
The Automatic Transmission is more reliable in performance and can easily controllable at high speeds due to its technology.
- Torque Multiplication.
- Fuel Economy
- Automatic Transmission Cars or Vehicles does have a Smooth Drive.
The AT vehicles are more comfortable and easy to handle because there is no manual work of changing the gears. They are becoming more expandable in the market, and at the same time, they are more efficient in power transmission too. The evolution of modern technology is taking place.