How Automatic Watches Work: A Simple Guide for Beginners

Have you ever asked yourself how automatic watches work?

An automatic watch is a watch that keeps operating without using any electric sources despite being a machine. It sounds shocking, isn’t it? It is also known as a “self-winding” watch, which means the watch winds itself with the energy stored inside a weight called a rotor.

This part will spin when you move your arm or wrist. This human-made energy will power the timepiece and keep it going when you are not wearing your watch at night.

Another shocking thing is that this stored energy can keep an unworn watch running up to 72 hours. If you are curious about how this tiny piece of machinery can function, then keep on reading. We will show you the answer soon through this article.


What Is Included In An Automatic Work?

One fact is that this automatic watch uses mechanical movements. A power reserve – consists of different mechanical pieces: including various gear, springs, and rotors – is an intricate mechanism that functions to allow the watch’s hand to move. In this part, we will introduce you to the components of the watch.

The Rotor

It is a half-circle weight that can swing through any degree in 3D space to counter the exact motion of the users’ wrists. With the help of other gears, the movement of this part can wind the mainspring to produce mechanical energy for the watch to use.

The Reversing Mechanism

This part is placed between the rotor and its gears. The mainspring is able to spin due to the circular motion of the rotor. This mechanism consists of two wheels, each made up of a top and bottom disc connected by a springless pawl that unclicks one wheel then the other.  The unclicking process depends on the direction of rotation.

The Crown

the watch crown

The crown is a button on the side of the watch. You can use this to wind the watch manually when the crown is pushed in. Remember to turn carefully and stop when you feel some restriction from it. Another thing you have to take into account is that pushing out the crown will enable you to set the hands to your will.

The Mainspring

This coiled piece of metal is the primary power source of automatic movements. It can store energy by tightening the spring using kinetic energy coming from winding the rotor, and it will continuously release some strength as it’s unwinding.

Each mainspring can store a different amount of energy, thus affecting the range of time used to wind the watch when it’s unworn. Watches’ interval usually stays between 10-72 hours.

The Gear Train

The gear train consists of several internal gears that enable other parts to move. Energy used to power the watch is transferred from the mainspring to the escape wheel.

The Escapement

This piece is considered as an internal brake for the system. It is the equal parts of the energy transferred from the mainspring to the gear train, which is made to ensure the same amount of energy is provided at different times.

How Automatic Watches Work?

Now that you get the hang of the essential components inside of an automatic watch, we will guide you on how the timepiece counts time and drives the hands to spin. Let’s take a closer look:

Step 1:

It’s all started with the power source: the human wrist. By wearing the watch, the rotor inside will be triggered to move, thus spinning the spring.

You can also turn the spring using the crown. Remember not to pull it out, or you may accidentally change the hand of the watch rather than winding it.

Step 2:

The circular motion – either coming from the wrist or the spinning movement of the crown – transfers the mechanical energy to the gears inside the gear train. Then the gears begin to rotate to deliver this energy to the escapement.

Step 3:

Energy will be provided periodically to the balance wheel from the escapement part. The range for the second hand, the minute hand and the hour hand are precisely calculated to mimic the exact time interval: 1 hour = 60 minutes = 3600 seconds within a small error margin of 1-2 milliseconds.

Step 4:

The balance wheel will now be pushed back and forth to maintain its oscillations by consuming the energy given by the mainspring.

Step 5:

Each of the balance wheel’s swing will advance the gear train an amount of force to drive the hands that are mounted on the gears.

Step 6:

The hands then will begin to turn. You can see the movement of each hand created by this system. By using reduction gears, the hands can rotate with different rates, which makes the second hand faster than the minute hand and the hour hand.

Some Notes To Take In Mind About How Automatic Watches Work

  • If you don’t wear this watch frequently or even if you do, it’s crucial to provide the timepiece with manual winding twice a week so that the hands will be running smoothly.
  • Lubrication is also necessary for mechanical watches that use gear and metal pieces to prevent the parts from rusting and also to ensure the watch’s performance is perfectly continuous.
  • Consider a schedule for maintenance. It is recommended to have a thorough check-up every five years. With the help of the experts, your watch is sure to be safe and sound.
  • When you first buy this watch, it usually comes unwound. Don’t forget to fully wind it the first time you use it to ensure that the automatic watch runs smoothly without any problem.

Final Thoughts

That’s everything you need to know about how these fantastic self-winding watches function. Not only does it comprise a complicated and intricate mechanism, but it also does not require any batteries.

With a complex system and an intriguing look, this product may come in a little on the luxury side for any interested people.

However, they won’t cost you an arm and a leg to have one. We hope that you can find the best automatic watch that perfectly suits you through this “How Automatic Watches Work” article.

Further reading:

History of Automatic Watch – History of Modern Watch

10 Milestone Moments in the History of the Wristwatch