Tourbillon was patented by watch making Master Abraham Louis Breguet. That patent has long since expired. Tourbillon is French for "whirlwind." This is because the mechanism literally spins on itself. Breguet's ideas was essentially to house a clock within a clock.
If you have a balance wheel that rotates, rotating on itself. If you understand the concept of a balance wheel, you know that it does not just turn endlessly in one direction. Rather, it moves in a back and forth manner, like a revolving pendulum. This is often referred to as balance wheel oscillation. In fact, a balance wheel is a pendulum, and the consistency of its back and forth rotations are the basis for mechanical watch movement accuracy. Of course, if the frequency is higher, likely by right, it would be more accurate. That is why Grand Seiko has a Hi Beat of 36,000 cycles per hour.
No matter what type of tourbillon used, the purpose is the same, to counteract the effects of gravity that may alter the accuracy and reliability of a balance wheel's oscillations.
A tourbillon is a in fact a balance wheel that itself rotates, but the balance wheel rotates in one direction (not oscillation), and it typically make full rotation every 60 seconds, but some design rotates every 30 seconds. For this reason, the tourbillon is often used at the seconds counter when it is used in a watch. A convenient way of putting in a second counter.
The main theory behind how a tourbillon is supposed to work, is that the balance wheel rotates to all positions in purpose of off setting the effect gravity might have on it being stuck in one position consistently. So if the balance wheel is constantly moving, then minor deviations here and there will be canceled out. But that is purely theory, as our hands are moving in all direction, the watch is not placed in juts one position. The cancellation effect is multi-degree-variation-complex. There is no fixed rate of gravity cancellation in each of the gesture position.
Most watch manufacturer actually agree but not to admit that even if the tourbillon is able to perfectly cancelling out rate affecting effects of gravity on a balance wheel, this is not the key to ensuring accuracy.
There are researches that have shown that Breguet's theories on tourbillon’s improvement are neglectible or even not effective at all on accuracy.
This carries a result that all effort in making and implementing a tourbillon movement does almost nothing to increase accuracy. Instead, a well constructed traditional watch that is finely tuned will beat out a tourbillon based watch anytime in terms of accuracy.
Audemars Piguet, Patek Philippe and Blancpain, among others headed this movement. The first tourbillon-based watches were interesting, but lacked much of what people needed in a watch. Like the AP introduced in 1985, it is delicate, semi auto-wound of low efficiency, and often not very easy to read.
20 years later, automatic tourbillon movements arrived along with a number of aesthetic and functional variations, but of course the nature of the movement provided that it would always be delicate.
As such tourbillons will always remain a piece of art and miracle for curiosity, rather than watch improving technological innovations.
There are really only two reasons for a tourbillon based watch, and neither of them have anything to do with increased accuracy or reliability. A tourbillon is interesting and excited to look at. It is always in motion and attracts attention and really makes the watch seem more alive beside tick-taks,. This is especially true with the multi-axis tourbillon movements with their constant gyration. The visual splendor is there, but arguably not worth the incredible premium. Moreover it brings us such tourbillon watch is pure showiness and prestige.
Attached is the famous Blancpain Torubillon, It is simple design, it works! Blancpain Tourbillon would give you extra viewing effect beside accurate time keeping, why not?