You already know that a high majority of Orient’s watches are mechanical, and that they’re powered by you, the wearer. Like a little engine, all the small parts serve a purpose and work together, but how does a mechanical movement actually work to display the time?
Assuming that the watch is free of other complex complications (like a power reserve indicator), there are a couple of key parts to highlight: the power source (be it a crown or oscillating weight), the mainspring, the gear train, the escapement (escape wheel), the pallet fork, and the balance wheel. The process by which these parts work together not only makes the watch physically tick, but is a means of effectively storing energy. This allows a watch to have a power reserve (Orient watches have an average power reserve of 40+ hours), and prevents the watch from suddenly stopping right after you take the watch off your wrist.
Here’s a simplified version of how a watch keeps time, with help from the illustration above:
1. The watch receives power, gathered from turning the crown (in a hand-wound watch) or by initiating the oscillating weight (also called a rotor in an automatic watch) with natural movement.
2. The energy gained from those processes is stored and dispersed by the mainspring, which looks like a coiled piece of metal.
3. The mainspring disperses this power to a series of gears called the gear train. The turning of these gears helps to continuously transfer energy.
4. The last gear in the train meets the escapement, an important part that parcels a consistent amount of energy with each individual turn. This helps regulate the gear train from spinning too fast and exhausting all the energy at once.
5. Each turn of the escapement moves the pallet fork, which is attached to the balance wheel. The escapement and the pallet fork team up to make the balance wheel swing back and forth. The swinging motion of the balance wheel is usually visible through the exhibition case back or open heart design of a watch.
6. Many consider the balance wheel to be the “heart” of the watch since it powers the hands of the watch. When a watch movement is serviced for timing accuracy, the balance wheel is what’s adjusted to move faster or slower.