How Do Automatic Watches Work
In the watch industry there are a lot of different movements that power different styles and price points. One of the most popular, and often overlooked, movements is the automatic watch movement. Automatic watches don’t need batteries to keep time, instead they capture energy from the wearer’s regular arm movements to keep them ticking.
Powered by a half-moon shaped weight that oscillates as you move your wrist, the rotor behind the case of an automatic watch spins around every time you move your arm. As it does so, it twists a part of the watch known as the mainspring. The excess energy is then stored as a power reserve, keeping the watch ticking when you aren’t wearing it. At some point the stored energy will run out though, and the watch won’t work until it is worn again.
The first mechanical automatic watch was created by Abraham-Louis Perrelet in 1770, and he used a side weight to capture the energy generated. Later watchmakers improved the design, eventually settling on three main designs: center-weight, rotor and lever systems. The lever system consists of a lever that raises and lowers in response to the mainspring’s natural unwinding. The rotor system uses a half-moon shaped rotor that is rotated by a shaft based on the angular momentum of the watch. The center-weight system is much simpler and requires fewer moving parts than either of the other two systems.
All automatic watches use the same basic mechanism to capture and store energy, but how they do it is slightly different. The most important component is the rotor, which moves in response to your movements. The rotor is attached to a set of gears that are connected to the escapement, a small series of internal gears that make the watch hands and other parts move on the face.
When the watch is fully wound and running, the rotor moves far enough that it causes the escapement to move back and forth five to ten times a second. watch automatic causes the balance wheel to spin, and it is this rotation that meters the time.
To keep the balance wheel spinning at the correct rate, the escapement needs to be released from the rotor every time it passes the regulating pin (a part that keeps the escapement from moving too fast). To do this, a small device called a hairspring is attached to the balance wheel and anchored to a ratchet. As the rotor spins, the ratchet also moves back and forth to apply the energy required to keep the balance wheel spinning.
Over time, the rotor and escapement will need to be replaced. When this happens, it is important to understand how to wind an automatic watch properly to avoid causing damage. It is important to never over wind your automatic watch, so be sure to check it regularly and make sure the crown is always pushed in before turning it. If you do this correctly, the watch will be able to retain its power reserve and continue keeping time without needing any help from the wearer for quite some time.
