What are the main parts inside the watch movement?
There are five main operating parts inside the movement of the watch, such as Center Wheel, Third Wheel, Fourth Wheel, Pallet Fork, and Escape Wheel. They are all indispensable, and each is an important support point that enables the watch to function and travel properly. You know what they do, let's take a look at what they do inside the watch movement.
The center wheel is appropriately named as it usually is in the center of the movement. It is driven by the barrel and rotates once per hour. On the dial side of the movement, the minutes hand is attached to the center wheel via the cannon pinion.
The third wheel sits in between the center and fourth wheels. It makes possible the large increasing gear ratio of 1 to 60 when considering the rotational speed of the center and fourth wheels.
The fourth wheel rotates once per minute. In movements that display seconds in a sub-dial, the seconds hand is attached directly to the extended fourth wheel pivot on the dial side.
The pallet fork is one part of the device known as the escapement. The pallets on the pallet fork interact with the escape wheel and cause the pallet fork to move back and forth. This motion gives energy to the balance wheel, causing it to oscillate.
The escape wheel is one part of the device known as the escapement. The club-shaped teeth on the escape wheel interact with the pallet fork to translate rotational motion into lateral impulses.