Many friends who know a little about machinery know that in all kinds of machinery, the role of the gear is very large, just like a nail in a building, it seems that its volume is very small, the whole building Buildings can't have any effect, but once it's damaged, it can lead to a series of chain reactions, and we often see gears that are common in items, alarm clocks, watches, and more sophisticated instruments that contain gears. As long as you carefully observe these gears, you will find that their number of teeth is a certain number, not a random single digit, not dozens of them, usually no less than 17 . Many friends will be puzzled. Why is there such a rule?
 
In order to ensure a very good transmission between the two gears, the gears are generally not too small, otherwise problems will occur during the connection. Only the connection between the two can be very smooth, to ensure that the machine can run in a smooth state. The intermeshing between the gear and the gear also requires precise measurement. The angle between them, the length they eat, and the pressure generated when the two gears mesh with each other are highly detailed. After that, if the result is too small, if the index is too small, its root will be eliminated. This is called root cutting. However, there is a situation in which if the part to be cut is small, the strength and stability of the gear will be greatly reduced.
 
Although for gears, if his words are small, he can still run, but if there are only 17 teeth, then a certain point on this gear may get a uniform force because it is The extra part, 17 is a prime number after all. If you insist on using this gear number, then every revolution may cause some errors, and the 17th tooth may be very worn, if it can be barely maintained in the short term, but Once in this state of wear for a long time, it is very likely to cause damage to the gears, which in turn causes the entire machine to be destroyed.
 
Therefore, the number of teeth of the gears is also very strict and required, not only for their height width and the spacing between the teeth and teeth, but also for the experimental improvement during the production, and then studied for him. After a thorough thoroughning, choose the best solution. Therefore, even all the tiny gears we see now condense the hard work of many people.