The first generation of Jaeger-LeCoultre's spherical tourbillon

　　Jaeger-LeCoultreIt possesses a unique design philosophy in the development of mechanical watch movements. Many of its technologies have become signature expertise within the watchmaking industry, particularly its mastery of the tourbillon, the most classic complication in horology.

　　The earliest multi-axis tourbillon

　　I have not found precise historical records for the origin of the multi-axis tourbillon. Through extensive patent research and analysis, I found an invention patent from 1978 by the Englishman Anthony George, which may be the earliest multi-axis tourbillon mechanism. From the schematic diagram, we can see that this tourbillon features two axes, A1 and A2, intersecting perpendicularly. Power is supplied by gear 5, which drives the outer axis carriage input wheel 8. Simultaneously, through the meshing of gear 10 with the crown gear 9, power is transmitted to the inner axis tourbillon to drive the regulating mechanism, causing the entire dual-axis tourbillon to rotate along multiple angular trajectories. Theoretically, this more effectively counteracts isochronism errors caused by gravity, thereby improving timekeeping accuracy more effectively than a flat tourbillon; this should be the theoretical foundation of the multi-axis tourbillon.

　　Jaeger-LeCoultreFirst generation spherical tourbillon

　　In 2004, Jaeger-LeCoultre's master watchmakers cleverly combined tradition with innovation, demonstrating a greater ability to fully utilise existing technology to create a masterpiece—the Gyrotourbillon 1 1, housed within the new 177 calibre.

　　Technical features

　　1. The spherical tourbillon 1 consists of 112 parts, with a total weight of only 0.336 grams. The outer carriage is made of aluminium alloy, while the inner carriage is crafted from a combination of aluminium and titanium alloys. Due to the low density of aluminium alloy, the outer carriage manufactured via five-axis CNC weighs only 0.035 grams; if it were made of stainless steel, it would weigh 0.11 grams. The advantage of aluminium alloy lies in its excellent density, strength, stability, and corrosion resistance, properties often utilised in aviation and high-performance engines, making it an ideal material for a tourbillon.

　　2. The inner cage of the Gyrotourbillon 1 rotates at a speed of 1 revolution every 24 seconds, while the outer cage rotates once every 1 minute. The balance spring system within the inner cage has an oscillation frequency of 21600 vibrations per hour. The balance wheel is crafted from 14K gold, and the hairspring utilises a traditional Breguet overcoil. It also features free-sprung balance technology, as evidenced by the adjustable weights set on the balance wheel, which are also crafted from 14K gold. The tourbillon structure housed within the inner cage adopts a relatively rare vertical configuration (another example of this type of setup is the patented vertical flipping tourbillon by Panerai). The structural characteristic of this type of tourbillon is that the cage axis is set perpendicular to the balance wheel axis, and the planar connection between the escape wheel and the second wheel is modified into a vertical connection. Due to this configuration, the tooth profile of the second wheel and the escape wheel is changed from straight teeth to bevel teeth.

　　3. The spherical tourbillon 1 is well-considered in terms of shock resistance. Its balance wheel axis is equipped with two shock absorbers (a standard configuration), while both ends of the inner and outer carriage axes are also fitted with shock absorbers. With a total of six shock absorbers, the overall resistance to external shocks is significantly enhanced. Furthermore, this tourbillon is set at a 37-degree incline within the movement, allowing for a better appreciation of the dynamic mechanical beauty of the spherical tourbillon in motion.

　　4. The 177 movement, which powers the spherical tourbillon, is equipped with a composite winding system controlled by sapphire crystal. Due to the wear resistance and low surface roughness of sapphire, this setup effectively reduces friction between the mainspring and the barrel, ensuring a power reserve of up to eight days. A clear and legible power reserve indicator is positioned to the right of the tourbillon on the dial.

　　Summary: The success of the first-generation spherical tourbillon laid a solid foundation for this tourbillon series, particularly in terms of its overall structure, which transitioned from its infancy into a growth phase.