The English term for "陀飞轮" is "Tourbillon." I feel this is, aside from "Coca-Cola," the best-translated Chinese noun in terms of sound, form, and meaning—it’s incredibly fitting. The "Tourbillon" is widely recognized as one of the most complex structures in watches, with both manufacturing and assembly being quite challenging, which naturally makes it expensive. A Swiss luxury watch brand like Jaeger-LeCoultre, using precious metals for the casing, would likely sell a "Tourbillon" watch for no less than 400,000 to 500,000 RMB.
In early introductions about "Tourbillon" watches, they were almost universally described as capable of balancing or compensating for positional errors in timekeeping and resisting the effects of gravity, giving the impression that they should be more accurate. In reality, this is a misconception. There are many instances where simple issues are unnecessarily complicated, depending on your objective. While watches indeed have complex designs and structures aimed at improving accuracy, long-term stability, and additional functions, they also have their "showy" side—namely, their aesthetic appeal, craftsmanship, and entertainment value. Watches, much like people, can exhibit "dual personalities." Sometimes they resemble wise elders, and other times, playful children, ultimately reflecting human characteristics since they are man-made.
Some even claim that "Tourbillon" watches contradict the primary goal of enhancing watch precision. Ignoring its susceptibility to damage and high maintenance costs, "Tourbillon" watches not only fail to improve timekeeping accuracy but may even reduce it. The supposed benefit of "reducing or compensating for positional errors in wristwatches" is merely a minor "additional advantage" that gets overshadowed by various disadvantages it brings. This is akin to a bald man having the "additional benefit" of never needing a haircut.
Some amateurs misunderstand and follow blindly, claiming that "Tourbillon" is a unique escapement design. However, beyond its transmission structure, there is no "revolutionary" fundamental change; it's still made up of the same number of parts, just with an added rotating frame that makes all components smaller. Traditional watches (clocks) have gears and plates with fixed axle positions on the plates, making the wheels mutually fixed. However, in "Tourbillon" watches, the second wheel position is unusual—it features a strange "cage." This "cage" is supported and rotates around what was originally the second wheel's axis. Thus, everything after the second wheel, including the escape wheel, pallet fork, balance spring, small plates, regulator, and outer pin, is all housed within this "cage." The second wheel becomes a fixed support "grinding disk," creating motion within motion. The entire "cage," along with its contents, rotates as a whole, similar to how a second hand moves, with a basic rotation cycle of one minute. This results in the simultaneous movement of the balance wheel oscillating, the escapement mechanism transmitting impulses, releasing energy, and the "cage" rotating. Essentially, "Tourbillon" refers to a type of watch (clock) where the escapement mechanism is installed inside a rotating "cage."
Anything becomes mysterious when it hovers and spins, which is the characteristic of all mysterious things, from maglev trains to UFOs. Therefore, in old Beijing clock circles, "Tourbillon" was called "ghost pushing millstones," probably because back then, besides "ghost lights," the Beijingers knew little else, giving the term a particularly esoteric quality. In reality, "Tourbillon" isn't mysterious. Many so-called mysterious things are artificially exaggerated or created, and science's mission is to reveal and explain them in simple terms. The cage frame of the "Tourbillon" imposes a significant load on the watch's transmission system, so it must be made as light as possible. Therefore, all components are made extremely small, or titanium materials are used, with the overall weight being around 1 gram, composed of dozens of tiny mechanisms.
Personally, I believe that "Tourbillon" is essentially a gimmick, deviating from the original purpose of precise timekeeping. Its main goals are appreciation and craftsmanship. These watches are particularly delicate, luxurious, and extravagant. If you have the time and money, it might be better spent on improving precision and functionality. Nowadays, domestic watch manufacturers can produce "Tourbillon" watches, and some even offer double "Tourbillon" watches, such as those from Tianjin Seagull and Beijing brands. I've seen a "Tourbillon" watch produced in Beijing, with a price nearing 2 million RMB. Similarly, in Switzerland, "Tourbillon" watches are sold at astronomical prices. Moreover, the ability to make "Tourbillon" watches is undoubtedly a "prestige project" for any brand.