Mechanical Basics

What is an Automatic Transmission System?

Automatic Transmission System (or Automatic System or ATS) is also called as Multi Speed Transmission System or Self Shifting Transmission System, is a process of transferring the power (power that generated by the engine) from the Automobile Engine to the Gearbox automatically. Generally, there are two types of transmission systems, which includes Manual Transmission System and Automatic Transmission System.

Manual Transmission vs Automatic Transmission

Generally, the Manual Transmission System in Automobile (Cars or Trucks) requires manual or human interference to change the gear ratio for increasing the torque and speed according to the vehicle position, but the working of Automatic Transmission System in Automobile (Cars or Vehicles) does not require any manual efforts to change the gear ratio and torque. The types of Gears that play a prominent role in working of Automatic Transmission System is Planetary Gearset, also called Epicycles Gears.

Also Read:

What can we learn from this post?

  • Automatic Transmission System Gearbox
  • Parts of Automatic Transmission System Gearbox
  • Working of Automatic Transmission System
  • Types of Automatic Transmission Technologies
  • Automatic Transmission System in Automobile
  • Types of Modes in Automatic Transmission System
  • Advantages of Automatic Transmission System
  • Conclusion

Automatic Transmission System Gearbox:

The transmission of power from engine to the propeller shaft is all because of Gearbox. Such Gearboxes does consist of different types of Gears, which includes Spiral Gear, Helical Gear, etc. But the Automatic Transmission does consist of special gears called Planetary Gears (the combination is called as Planetary Gear Train) or Epicyclic Gears. As this process is automatic, the gears are also called as Automatic Transmitting Gears.

Due to this planetary gear train (or automatic transmitting gears), the vehicles can automatically change the Gear Ratio according to the speed of the vehicle or the situation of the vehicle.

Parts of Automatic Transmission System Gearbox:

Parts of Automatic Transmission System

As mentioned, the typical Automatic Transmission System Gearing is because of Planetary Gear Train System and it does consist of different gears according to size and construction. Even though they are called as Spur Gears according to the construction; their application and construction let it called by different names. So, a Planetary Gear Train has

  1. Sun gear
  2. Planetary gear
  3. Ring gear
  4. Carrier
  5. Clutches
  6. Bands

The Sun Gear, Planetary Gear, and Ring gears in Planetary Gear Train 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 in Automatic Transmission System 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.

Working of Automatic Transmission System:

What is an Automatic Transmission & How Does Automatic Transmission Work?

Focusing on the working of Planetary Gear Train, Automatic Transmission system consists Torque Converter, which acts like a Clutch for whole system: that will connect Engine and the Planetary Transmission system or Planetary Gear Box. It helps to Engage and Disengage the input, and output shafts of Engine and Gear Box 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 vary depends upon this Planetary Gear Train System. Similarly, the reductions or overdrive ratios also depends upon the Planetary Gear Train. The Planet Gears is housed by Carrier, so all the three planet gears can rotate at 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; nevertheless, 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 too.

Types of Automatic Transmission Technologies:

There are three types of Automatic Transmission Technologies in the market and they are

  1. Automatic Manual Transmission (AMT),
  2. Continuously Variable Transmission, and
  3. Dual Clutch Transmission

Note: You can read about these three types of Automatic Transmission Technologies in upcoming articles very soon.

Automatic Transmission System in Automobiles:

The Automatic Transmission System in Automobiles can be found in Cars, and Trucks. All Luxury Cars are built with Automatic System but nowadays some of the Non-Luxury cars are also using Automatic Transmission technologies for a good performance so, some of the Luxury and Non-Luxury Automatic Transmission System cars or vehicles companies are as follows:

Luxury Automatic Cars:

  • BMW Cars Mercedes
  • Audi
  • Porsche
  • And Many more

Non-Luxury Automatic Cars:

  • Hyundai Creta
  • Toyota Fortuner.
  • Volkswagen Tiguan
  • And Many More.

We can find Heavy and Transporting Vehicles with Automatic Transmission System, some of the models are

What is an Automatic Transmission & How Does Automatic Transmission Work?

  • The new Eicher Pro 3016.
  • The Mercedes Vehicles.
  • Tata Buses.

Types of Modes in Automatic Transmission System:

What is an Automatic Transmission & How Does Automatic Transmission Work?

The Automatic Transmission System in Automobile 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 System is more reliable in performance and can easily be controllable at high speeds due to its technology.

  • Torque Multiplication.
  • Fuel Economy
  • Automatically Transmitting Cars or Vehicles do have a Smooth Drive.

Also Read:


The Automatic Transmission System vehicles are more comfortable and easy to handle because of less effort in 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.

Leave a Reply

Your email address will not be published. Required fields are marked *