Technology  
Eterna Spherodrive
Greater efficiency for increased longevity
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Presentation

Back in 1948, Eterna astonished the watchmaking world with its ball baring-mounted low-friction rotor system for self-winding movements, known as the "Eterna Matic".

 

Between 2007 and 2009, a team of engineers, designing engineers and watchmakers buckled down to make news with the same principle, this time involving a ball bearing-mounted barrel.

 This dual ball bearing represents a quantum leap in the quality of the gear train mechanism. 
The idea

At the heart of every mechanical movement lies its energy storage and delivery system, called the barrel. It contains and controls the mainspring whose winding and slow unwinding drives the movement, generating extreme friction and tension in the process. This centuries-old system has

 now been vastly improved by the inclusion of strategically positioned ball bearings fitted with tiny but self-lubricating zirconium-oxide spheres. Called Eterna Spherodrive, these bearings allow the various parts involved to rotate much more smoothly, generating far less wear and tear and markedly improving the watch’s overall performance

 

The advantages
 
Longer life thanks to the rolling movement which helps mitigate the immense pressures in the watch movement, as well as friction and wear.
 
The stability of the spring barrel affords optimum engagement with the gear train and improves energy transfer.
 
No lubricant (oil) needed due to bearing’s lubricant-free zirconium oxide balls
 
Increased power reserve thanks to use of thinner mainspring.
 
Assembly and service are much simplified and less prone to error, since the bearing requires no adjustment or calibration.
 
Less labour-intensive service work: the spring barrel is subject to far less wear and tear than conventional systems, and no longer needs routine replacement after three to five years. 20 years of simulated ageing resulted in barely any wear.