RM 025 TOURBILLON CHRONOGRAPH DIVER'S WATCH 525.45A.91B
- Movement Type: Tourbillon
Richard Mille RM 025 525.45A.91B
Herald at their intial release in 2001 as a break from the past and a new direction of horology, the wristwatches of Richard Mille were from their very inception, extraordinary and uncompromising.
TECHNICAL SPECIFICATIONS OF THE TOURBILLON CHRONOGRAPH DIVER’S WATCH RICHARD MILLE RM 025
CALIBER RM025: manual winding tourbillon movement with hours, minutes, chronograph, power reserve, torque indicator, function indicator.
Diameter: 50.70 mm x 19.20 mm
MAIN FEATURES
(MANY OF WHICH ARE MAJOR TECHNICAL INNOVATIONS)
POWER RESERVE
Circa 50 hours (numerical indications to the left of the barrel).
CARBON NANOFIBER BASEPLATE
This is an isotropic composite material created from carbon nanofibers molded under a high pressure of 7,500 N/cm2 and a temperature of 2,000˚C, resulting in a material with high mechanical, physical and chemical stability in all directions. The ribbed perimeter of the movement plate assures the highest rigidity between the plate and bridges. Carbon nanofiber composite structures such as this are amorphous, chemically neutral and dimensionally constant within a very wide range of operating temperatures, including those outside of normal ranges. This stability assures the highest integrity of the movement’s going train under all conditions.
CHRONOGRAPH (Column wheel in titanium)
The modern architecture of this movement has allowed for the consistent and rational arrangement of its constituent parts, avoiding unnecessary superimpositions and permitting the best possible use of thefunctions with technical solutions. For example, research was conducted into the geometrical design of the column wheel that controls the different levers to ensure the perfect, long-term simultaneity of the functions, a feature that is essential for a high performance chronometer. This design was implemented in order to achieve a high degree of continuity of the settings and an unfailing repeatability of the functions. Operation: the user can start or stop the chronograph function via the pusher located on the lower left at 8 o’clock. The hands are reset by pressing another pusher located on the upper left at 10 o’clock.
TORQUE INDICATOR
Supplies information about the tension of the mainspring, and allows the optimalization of the chronometer function of the movement. Below 53 dNmm, the spring is considered to be too slack, while above 65 dNmm, the excessive spring tension can adversely affect the mechanism’s operation, or else actually endanger it. These indications appear on the numerical zone to the right of the barrel.
BALANCE WHEEL WITH VARIABLE INERTIA
This type of balance wheel, which represents the ultimate in innovation, guarantees greater reliability when subjected to shock and also during assembly and dismantling of the movement, thus achieving better chronometric results over time. The index is eliminated, thereby allowing a more precise and repeatable adjustment.
FAST ROTATING BARREL (6 hours per revolution instead of 7.5 hours)
This type of barrel provides the following advantages:
• The phenomenon of periodic internal mainspring adhesion is significantly diminished, thereby
increasing performance,
• Provision of an excellent mainspring delta curve with an ideal power reserve/performance and
regularity ratio.
BARREL PAWL WITH PROGRESSIVE RECOIL
This device permits an appreciable winding gain (circa 20 %), especially during the start of winding. It also aids in the even distribution of the mainspring’s internal tension.
BALANCE SPRING
In order to improve performance, lengthy research was carried out to determine a special curve of the hairspring, aimed at reducing the shifting of the centre of gravity during functioning.
ESCAPEMENT
New in-line escapement design, aimed at reducing friction.
FUNCTION INDICATOR
In a manner similar to a car's gearbox, the function indicator allows one to see the winding, neutral and hand setting positions as the crown is pulled out. Each position is indicated via a hand at 4 o’clock displaying the following functions: W (Winding) – N (Neutral) – H (Hands).
CLOSURE OF THE BARREL COVER USING EXCENTRIC SCREWS
This development is again part of the intention to make servicing easy, logical, and of a very high mechanical standard.
WHEEL BASED TIME SETTING SYSTEM (back of the movement)
Provides smooth time setting functions through the elimination of engaging friction by replacing it with rolling friction.
SPLINE SCREWS IN GRADE 5 TITANIUM FOR THE BRIDGES AND CASE
This permits better control of the torque applied to the screws during assembly. These screws are therefore unaffected by physical manipulation during assembly or disassembly and age well.
TOOTH SYSTEM OF BARREL AND THIRD-WHEEL PINION WITH CENTRAL INVOLUTE PROFILE
The wheel with a central developing profile and a pressure angle of 20° promotes rolling movement more effectively, compensates differences between centers, ensures excellent torque transmission and a distinct improvement in performance.
OTHER FEATURES
• Center bridge in titanium
• Movement diameter: 38.95 mm
• Thickness: 8.12 mm
• Tourbillon diameter: 12.30 mm
• Diameter of the balance wheel: 10.00 mm
• Number of jewels: 30
• Balance wheel: in GLUCYDUR, 2 arms, 4 adjusting screws.
• Moment of inertia: 10 mg.cm2, lever angle 53°
• Frequency: 21,600 vph (3 Hz)
• Balance spring: ELINVAR by Nivarox
• Shock resistance: KIF Elastor KE 160 B28
• Barrel shaft: in chronifer without nickel (DIN x 46 Cr 13 + S),
which has the following characteristics: non-oxidizable – antimagnetic – hardened.
The watch is water resistant to 30 atmospheres (300 meters) following ISO 6425 diver’s watch norms. This is achieved with a unique tripartite case design complemented by the additional integration of the lugs into the case’s torque screw system, as well as the torque limiting crown and a new design of watertight pushers. The lugs are in 18-carat red gold, with screws for the attachment of the rubber diving strap.
BEZEL
Built up of three layers connected with 22 screws, turning unidirectionally following ISO 6425 norms to avoid timing miscalculations. The use of an additional screwed system attaching the bezel to the watchcase makes it absolutely stable as well as impossible to inadvertently dislocate or loosen. In addition, the use of screws allow for perfect adjustment since the bezel is not tensioned into position. For clearer visibility under murky conditions, starting at 12 o’clock, the five-minute markers of the first quarter are highlighted red.
STRAP
The RM 025 has a new strap, made of perfluoroelastomer Kalrez®*. This material is ideal for environments such as pharmaceutical industry, aerospace and aeraunautics environments requiring a superior degree of purity. Kalrez® effectively reduces absorption, desorption and products of extraction, ensuring minimal contamination. In fact, the perfluoroelastomer Kalrez® strap provides almost total chemical resistance, maintaining its properties at temperatures up to 327°C. Likewise, the strap ’s composition allows for optimal watertight protection, synonymous with longevity, as well as negligible residual deformation, which gives Kalrez® pieces their resistance to the extreme pressures imposed by deep-sea conditions. But the strap of the RM 025 is just as resilient to the pressures of daily life, unlike traditional rubber straps which are notoriously weakened by heat, UV light, chemical agents such as cleaning products and bleach, even pollution... The strap is manufactured by Biwi SA**, a Swiss firm specialising in the moulding of high-precision vulcanised elastomers like rubber and silicone, as well as technical plastics used in the manufacture of watchmaking components and medical parts.