The rubbed Wostok 2416B is a very popular russian selfwinding movement, which, especially in the 80s and 90s, was used in the “Kommandirski” series of russian divers' watches.
Its dimension is 24mm. If you add the place, the oscillating weight needs, it increases to 29.8mm.
Of course, in this movement, there are everywhere ruby bearings, except for the slowly rotating mainspring barrel. In total, especially by the elaborate selfwinding mechanism, 31 jewels are used.
As you can see not the whole space is used, which offers the base plate. This allows more space for the oscillating weight.
There’s a classical one-storey gear train with directly driven minuten wheel, third wheel, seconds wheel and escape wheel. The mainspring barrel is very large to achieve long running times.
If you look exactly, you can spot the center seconds arbour on top of the minute wheel. Since the minute wheel bearing is located a bit deeper on the mainspring barrel bridge, the third wheel can go over it and so indirectly drive the center seconds arbour without a need for a double third wheel. wäre.
Between balance cock and base plate, there’s a spacer of 0.04mm height. It’s an odd solution to adjust the height of the balance lock.
The shock protected three leg anular balance beats with 19800 A/h and controls a pallet lever movement of swiss type.
The effective length of the hairspring can be adjusted by a long hairspring key.
The way, the crown wheel is decoupled, is pretty interesting: On the lower side of the winding bridge, there’s a moveable bearing, which is held in position by a spring, and on whose upper side, there’s the crown wheel.
It is not clear, why such a mechanism is used, because due to the breguet clutch of the crown, the crown wheel is decoupled anyways.
One of the two exchange wheel axles for the selfwinding mechanism is on the gear bridge. It seems, like Wostok thought there’s a lot of force impinged and so it is rock solidly secured by two screws on the inner side if the gear bridge.
Even without mounted selfwinding mechanism, one of its gears has to be in postition. You can spot this transmission gear at position 4:30.
On the left, you see the spring, which holds the center seconds wheel on position, and you can also see, how the third wheel engages with the center seconds wheel.
The selfwinding mechanism is pretty elaborate with two change wheels and three transmission wheels of which one acts as clutch. This allows a bidirectional winding.
The left change wheel engages with the ball-beared oscillation weight. It also engages with the right change wheel. Both have got a “Gyrotron” (Girard-Perregaux) type construction, which takes care, that their lower gear always turns on the same direction, no matter in which direction the upper wheel turns.
Finally, there are a big and a small transmission wheel and the clutch wheel, which engages with the ratchet wheel and decouples the selfwinding mechanism on manual wind.
The clutch wheel with integrated pawl engages in one and disengages in the other way.
Inside the change wheel, there are five ruby discs, which realize, just like in a Gyrotron from Girard-Perregaux, the engagement of the lower wheel in one, and the disengagement in the other direction.
Both changer wheels are axle beared and held in position by a spring. The visible grinding tracks on the right one let guess, that this kind of fixation is less than optimal.
The oscillating weight with ins engraved “B” (for Wostok = cyrillic “Восток”) is ball-beared
On the yet empty dial side, you see the russian shock protection of the balance wheel, which is secured by two(!) screws and the quite internal located yoke winding system with its large and uniquely shaped setting lever spring.
The lever pallets can be accessed easily for oiling at position 11 o’clock.
The calendar mechanism offers a semi-fast correction by turning the hands back and forth between 8pm and midnight. It also offers an instant date switch at midnight.
For this purpose, a switching cam and a spring is used. The switching cam has got a pin, which engages with a slidin gear on top. The spring ensures a sudden unloading at midnight, with the pin engaged with the date ring, advancing it instantly.
The fine font of the date ring is typical for this movement. It reminds of early plotters.
On the Wostok 2416B, you can see, how far the oscillating extends the base plate.
|10 1/2''' (measured: 24,0mm)
|Number of jewels:
Glucydur anular balance
3 arms, russian
|Balance bearing / direction hairspring:
|yoke winding system
|Setting lever spring: