The key part of the auxiliary drive in mechanical watches is the display system. To put it plainly, how time is displayed. To explain the display system in professional words, the meaning is to allow the mechanical watch to calculate the time output mode, usually with the hour, minute and second hands to achieve. The second wheel is directly connected to the main drive train, while the minute and hour wheels are branched off from the main drive train. The wearer directly drives the minute and hour wheels through the set of dial hands, so as to quickly adjust the position indicated by the hour and minute hands to achieve the correct time display required.
Big three stitches
The most common mechanical watch display is commonly known as the ‘big three hands’, which refers to the hour wheel, minute wheel and second wheel are coaxially set at the center of the movement, and the hour, minute and second hands are installed, three length Different hands to indicate the hours, minutes and seconds, respectively. The hour hand is the shortest and thickest hand, working at a speed of one revolution every 12 hours. The minute hand is longer and thinner than the hour hand, working at a speed of one revolution per hour. The thinnest and longest is the second hand, which works at a speed of one revolution per minute, and it is the most conspicuous hand and the busiest hand. The second wheel connected to it is directly controlled by the speed control system to control its rotation speed. Therefore, the second is the timing basis of the mechanical watch, which directly affects the accuracy of the mechanical watch.
We have said that the main drive chain includes the drive train, drive train, escapement and vibration system, and the display system is connected to the main drive chain and integrated into it. In addition to the most basic display wheel train-hour wheel, minute wheel and second wheel, it also includes a straddle wheel that is responsible for changing the rotation speed. The span wheel is formed by integrally fixing the span wheel piece and the span gear shaft. It sets the well-known minute wheel that rotates once every 1 hour and the hour wheel that rotates once every 12 hours converted by the cross gear ratio. The basic transmission forms of the movement are divided according to the position where the two wheels meshing with the box wheel of the prime mover are set at the movement. Movement center) two categories. Then the transmission method of the display system is correspondingly divided into two types-the center two-wheel display system and the partial two-wheel display system, and the core to distinguish the two types of display systems is the friction wheel mechanism.
ETA2892 partial two-wheel movement
Friction wheel mechanism
The main characteristic of the friction wheel splitter mechanism is that the wheel splitter forms a friction relationship with the mated parts, which means that the two are integrated through an elastic structure and have a certain frictional torque. When the input torque is less than the friction torque, the two rotate synchronously; when the input torque is greater than the friction torque, one of the parts will be driven separately with respect to the part that cooperates with it. When the movement is running normally, the minute wheel rotates synchronously with the gear on the main transmission chain through the friction mechanism, and its rotation speed is one revolution per hour. When the time needs to be adjusted, the minute wheel is driven by the dial wheel train. Due to the friction relationship, this action will not affect the normal operation of the main drive in the movement. After the adjustment time is over, the two will rotate together through frictional cooperation.
Center two-wheel display system
The center two-wheeled display system’s friction minute wheel mechanism includes two parts-the center two wheel and the minute wheel.
The center two round top E is processed into a taper step. The middle and lower part B of the split wheel has a certain elastic thin wall and a groove recess, and the two form a friction fit relationship in these two regions. The A and B positions of the center two wheels are matched with jewel bearings, so that this wheel is controlled. The position C is processed to connect the shaft teeth with the box wheel; the position D gear is connected to the main drive train. The A position of the split wheel is an inner hole that matches the center second wheel. The C position is machined to connect the shaft teeth with the main drive chain; the D position is used to assemble the minute hand.
Center two-wheel display friction wheel
Partial wheel display system
The position of the sub-wheel A in the partial-wheel display system is an inner hole matched with the support shaft. The tapered step in the B position and the three elastic inner claws in the C position of the split wheel piece cooperate to form a friction relationship, and the effect is consistent with the friction split wheel mechanism of the center two-wheel display system. The D position is used to assemble the minute hand. The difference between the two-wheel friction split wheel mechanism and the center two wheel is that the function of the split wheel is equal to that of the center wheel in the movement. The split wheel is connected to the main transmission chain.
Partial wheel display friction wheel diagram
Colorful time display
1. The watchmaker of independent watchmaking brand URWEAK-Baumgartner’s unique secret is the satellite dice hour display. This design was born in the 1990s and has been for more than ten years. The feature of this technology is that the dice showing the hour number can rotate and revolve under the setting of the turntable. There are three dice that can be rotated on the turntable. Each side of the dice has 4 hours printed on it. Its regularity is that the difference of 4 numbers is 3, that is, a group of 1, 4, 7, 10, a group of 2, 5, 8, 11, and a group of 3, 6, 9, and 12. The minutes are displayed in a retrograde manner, and the two display the time through a linkage mechanism. In addition to the time display, the satellite display system can also be extended to the annual calendar display function. There are 12 months and the corresponding calendar is up to 31 days. This correspondence has a very tacit internal correlation with the 12 hours and 60 minutes. URWEAK implemented the coexistence display mode of satellite time and satellite almanac with CR-1001 Zeit Device;
2. Harry Winston opus11, an innovative design by French watchmaker Denis Giguet, has a very special time display, which fully reflects the designer’s concept of ‘deconstructing time’. The appearance of this watch is composed of three parts. The semicircular area in the upper left corner displays the minute, the semicircular area in the lower right corner is the base of the balance spring system, and the largest transparent circular area is the biggest highlight of this watch— ‘moving time display mechanism.’ ‘. The so-called traveling type refers to the display of time by a decomposed time digital disk carried by the satellite trains in motion. Each satellite train contains three pairs of irregular faces and is engraved with pre-calculated hours. These four satellite gear trains are located on a rotatable turntable at the same time. After rigorous planetary gear train calculations, one side of each satellite gear train is combined with each other and presented in the center of the dial to display the hour at that time. When the hour changes, the 24 literally set rotations on the four satellite trains are as if a group of small fishes shake their tails and disperse in a panic, waiting for the next meeting. The characteristic of the ‘walking time display mechanism’ is that the time display is composed of a time display digital dial in motion, and the biggest difficulty of this mechanism is the use of spatial solid gears, which is a small cone that I have been studying recently Gear linkage system;
3. The brand HYT combined mechanical watchmaking and liquid machinery at the 2012 Baselworld Watch Show to launch the world’s first hydraulically powered mechanical watch HYT H1. This movement was jointly developed by Bruno Moutarlier and the watchmaking team Chronode SA. The ‘hydraulic time display mechanism’ displays the flow of the fluorescent liquid for the hour controlled by the reservoir and the piston. The reservoir is used to store the fluorescent liquid for displaying the hour, and the piston provides the power for promoting the fluorescent liquid for the hour display. The hour fluorescent liquid flows out from the 6 o’clock position and the concave scale of the bezel indicates the hour digital display time. Two reservoirs are set at the 6 o’clock position. When one of the reservoirs is compressed, the other expands to form a liquid running in the catheter. With the continuous change of time, the volume of the fluorescent liquid in the tube increases accordingly. The meeting point of the two liquids is exactly the position of the hour at that time. When the time reaches 6:00, the fluorescent liquid will return in the form of a retrograde jump. initial position. This type of time display is definitely a unique initiative. The use of liquids provides engineers with more extensive thinking space for the development of mechanical watches. The successful experience of the hydraulic time display tells us that the design concept and design elements of mechanical watches can From any field, use the old saying ‘only the unexpected, not impossible’.
Author’s comment: The display of mechanical watches has a very important role as the output of time. With the evolution of the times and technological innovation, more and more imaginations have emerged, and an incredible way of displaying time has appeared. The reason is that many watchmakers will use the most direct time display of the watch as a stage for their own interpretation. The dial system corresponding to the novel display system is becoming more and more complicated, and it is gradually increasing in terms of design difficulty. .