Breguet

ei8htohms
8555

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the dial train is driven directly by the barrel

Hello Andrew,

In the picture of the back of the movement, what you have labelled the "hour pinion jewel" is in fact the "minutes pinion jewel".  Instead of having the minute hand mounted directly on a center wheel (as is traditional) or mounted on a compound cannon pinion that is driven by the the third wheel pinion (as is common in modern ETAs), the Tradition uses an indirect minutes pinion to carry the cannon pinion and minute hand as is also quite common in modern movements.  As the barrel turns, it drives the minutes pinion which turns once per hour and carries the minute hand.  Underneath the dial there is a reduction train whereby the cannon pinion drives a minute wheel, the pinion of which drives the hour wheel.  These part are controlled during hand setting via the rather complicated arrangement of gears just north of the keyless bits.

Planetary gearing is generally not easy to wrap your head around in my opinion without a good drawing of all the gears in the system.  For power resereve mechanisms, the super simple explanation is that the ratchet wheel drives the series of gears one direction when handwinding the watch and the barrel drives the system the other direction when unwinding (while the watch is running), and the difference between the two is shown by the power reserve display.  The "difference" part being "calculated" by the planetary gearing a little like a differential in an automobile.  To see how an automobile differential works, click here, and imagine that rather than the two axles being driven by the pinion shaft, the two axles were instead driving the pinion shaft in contradictory directions and the pinion shaft was showing the net output of the two.

Most watch companies these days do not sell parts to independent watchmakers, and certainly not without some kind of certification or authorization process.  If they don't sell parts, they are certainly not going to give out technical documentation about their movements, so unless you work directly for the brand or are authorized to repair them, you're not likely to get tech docs at all.  Some watchmaking organizations like the AWCI have technical documentation in their libraries for a wide variety of movements that they will copy for their members, but I rather imagine its only for older movements.  Basically yes, they expect all their watches to go back to them for service.

_john