page = bartosz ciechanowski
url = https://ciechanow.ski
An important aspect of two matching gears is their number of teeth. Each tooth in one gear meets with a space between teeth in the other gear, so within a unit of time both gears rotate by the same number of teeth. If the number of teeth in two gears is different, those gears can take a different amount of time to complete a single rotation. In the demonstration below, you can change the ratio of the number of teeth between the driving red gear and the driven yellow gear to see how it affects the speed of rotation of that yellow gear :
We’ll start with the mainplate , which forms the main body of the movement:
This mechanism protects the fragile tips of the balance shaft from breaking when the watch experiences a sudden jerk. Let’s see how these pieces act together when the balance shaft is jolted around:
Personally, I think this entire mechanism known as the keyless works is a real mechanical marvel. The intricate interactions are so well balanced and each part serves many different roles. Older pocket watches were wound by a separate key, with the crown being used only to set the time, but modern watches get away without having a winding key, which explains the keyless name. With just a few carefully shaped pieces and a single crown, we can control various settings of the watch. Before we move on, let’s secure the remaining pieces with the minute train bridge :
Notice that I’m highlighting a pair of yellow and blue gears only when they’re actively transferring power directly from the weight gear to the output gear . Only one such pair is active at a time – the other either spins idly, or acts as an intermediate to change the direction of rotation to make sure the output gear always winds the spring.
Watchmaking by George Daniels is a book dedicated to the process of actually making watches from scratch. While few will endeavor this journey, the publication also explains many of the considerations required when designing a watch movement and its parts. Many of the book’s pages are accompanied by pretty technical illustrations that help to explain the concepts.