MechDesigner: Model of Watch Swiss Lever Escapement.
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- เผยแพร่เมื่อ 21 ก.พ. 2015
- www.psmotion.com ; mechdesigner.support
[Sorry about poor quality. Please watch past first clip to see 'slow motion' interaction of impulse pin, pallet jewels]. Watch Swiss Lever Escapement, showing the interactions of the Balance Wheel, Impulse Pin, Pallet, Entry Anchor, Exit Anchor, Escape Wheel - วิทยาศาสตร์และเทคโนโลยี
Excellent video! I have been scratching my head trying to figure out how the hairspring gained back the energy. Your video shows what others don't, which is that the impact jewel disengages the pallet jewel, but then the escape wheel actually pushes and accelerates that same pallet jewel right after. Well done amigo, thank you.
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First class video. The best illustration of Swiss Lever Escapement I have ever seen!
Finally, I have found many answers to my questions in this excellent explanation. Thank you
Best animation of an escapement I've seen so far!
Thankyou the only animation and text that explains how this works without a load of gobbledook
Hey! Thanks for the nice comment.
Wonderful. Excellent graphics. Well worth pausing and figuring out. Well done. Thank you.
And thats it , good details!
Excelente video Gracias
Thank you very much
Is there an impulse being transferred to the balance wheel on both the exit and entry cycles? Also why is the exit side longer than the entry? Is that to provide more leverage to the balance wheel? Love the video!
I think I'm correct in saying that the balance wheel receives an impulse on both exit and entry cycles. Is the reason for the difference in length of each side of the pallet fork to compensate for the different impulse necessary for the compression and decompression of the hairspring? I hope I'm asking the question correctly.
I'll tell you what always bothers me about this action. The entry pallet receives a little lift but it doesn't look to match the big push that the exit pallet gets. I know I'm not being very scientific, but do I need to be? Am I missing something? I also need to ask about the half moon and guard pin. Is that to prevent flutter? If not what is it for? I have seen pin pallet arrangements that don't have banking pins. What do they do - waste energy? Nice animation. Thanks Berry G
the little bit of lift, or escapement wheel moving backwards is usually called recoil or draw i think, at first it used to be thought bad, but what it does is THAT actually prevents flutter, so if watch gets bumped, that draw force keeps the club against the pallet where it's supposed to. Now if a force were excessive and the pallet arm moves too much, it could hit the pin when it's not supposed to and stop the watch completely. The safety pin and guard pin prevent this from being possible. So the watch doesn't suddenly stop for period when encountering sudden movements.
The palets must more than offset losses. And then excess energy is checked by the balance spring?
The more energy in the hairspring the more energy it will lose each beat through the spring internal forces and through the impact of the impulse pin with the pallet fork during unlocking.
This will balance with the energy added each cycle based the current tension in the mainspring.
When a mainspring is nearly too unwound to keep time the balance wheel can drop below 180 deg of travel.
When the same mainspring is fully wound balance wheel movement can get over 300 deg each full cycle.
If the tension in the mainspring gets too high for the oscillator "rebanking" will happen and the impulse pin will start striking the outside of the pallet fork. th-cam.com/video/Rcqrb3_vin8/w-d-xo.html
If the tension in the mainspring gets too low the unlocking will take so much of the balance wheel momentum that the watch will fail to keep time, and eventually stop.
The difference between the two determines how much power a watch can store and use.
@@electrostatic1 The natural frequency and period of oscillation of the spring are important also. The period of the spring oscillation is the same no matter how many degrees it oscillates, within a reasonable range. But the further it swings, then the greater the velocity at the impact, and this eventually might be a problem, for the interaction between the 'impact pin', crescent, and banking pins'.
What is the middle prong for?
It doesn't appear to do anything.
Great video by the way.
Ah... does it stop the fork moving back until the hollow appears again?
The Guard-Pin can only move across when the crescent [the notch in the Safety-Roller that moves with the Balance Wheel] is also moving across. At all other times, the Guard-Pin, if the watch is knocked badly, would be prevented moving across by the Safety-Roller. So the Guard-Pin doesn't do anything under normal operation. It is stopped moving by the safety-roller before the Entry or Exit-Pallets can disengage from the Club-Teeth on the Escape-Wheel. If a pallet could disengage, then the 'impact pin ' would not be able to pass into the pallet and the watch would stop, or jam, or unwind uncontrollably, or all three, depending on the actual position of the pallet.
I'm going insane trying to figure this out! How is there no loss of energy when there is clearly friction between surfaces involved?
There is a loss of some energy, yes- but small of course.
The mainspring [not shown in the model] drives the escape-wheel. If the pallets weren't there to stop the escape-wheel then the escape-wheel would spin [whirrrr..] rapidly until the main-string becomes completely unwound -many complete rotations later. So the 'long-term' energy is in the mainspring, which is always trying to unwind the escape-wheel. The pallets regulate the unwinding, one tooth of the escape-wheel at a time. The pallets move because of the impulse from the impulse-pin/jewel on the balance wheel.
Energy is lost in the balance-wheel as the pallet has to lift the club-tooth a little, but this energy is paid back by the mainspring to the pallet when the club-tooth [driven by the main-spring] slides along and drives the underside of the pallet. The pallet drives the impact-pin and balance-wheel again to resptore any lost energy....
@@mechdesigner1722 that's makes it clearer, thank you!!!
@@mechdesigner1722 I searched youtube because I am putting together my first custom watch, and messed up when removing the stem for my 2824. While trying to solve one problem, I probably created like 3 more. Each "fix" took me deeper and deeper into the mechanics of my movement. I finally got everything assembled, keyless works functions smoothly, power transfers throughout out entire system, everything feels silky smooth and easy. BUT (a big one), the power just whirrrs through, exactly as you describe above. I had a feeling it was an incorrect pallet fork alignment. It was the one part I just wasn't sure "looked right" as I tried to test if it rocked back and forth and meshed with the teeth of the pallet wheel. Thank you for helping me confirm my suspicions!! Any advice as to how to install that pallet fork/mainspring?
What if the escape wheel hits the impulse face first, not the locking face of the pellet fork?
death
it would probably lock up
I don't understand why a watch doesn't run faster when it is fully wound.
The 'hair-spring' has its own natural frequency, or if you want , its time period between each oscillation is constant. It is also isolated from the Main-Spring by the escapement. With a fully wound Main Spring, you might be able to argue that it pushes the pallets harder during its escapement and back drive the hair spring more than when it is nearly unwound. However, even if this is the case, the natural frequency of the hair-spring does not change as its natural frequency is not a function of its amplitude of oscillation - within a reasonable range.
This isn't 360....more like 354
Is it?