What is the principle of screw
Note that the pole and the screw lift angle of the screwdriver, that is, the slope is almost vertical, because the general thread angle is also 2.5-4 degrees. This is where the leverage principle is applied.
From a man with a manual screwdriver or a powered tool drive to produce a force pushing a small box up the slope. The longer the length of the screwdriver, the more effort it is, or the slope at the slope - that is, the amount of lubricant applied at the thread.
How it works: Lever principle The screw itself is no theory, the screw thread is a long slope, but the angle is very small. You can assume that when you twist the thread, it is equivalent to pushing a square on the slope. Force analysis: box weight + friction and thrust from now on the use of the principle of leverage.
A simple mechanical one that can be used to overcome the difficulty of vertically lifting heavy objects. Distance ratio and force ratio are dependent on the inclination. Such as friction is very small, you can achieve very high efficiency
Screws are an example of this simple mechanical principle of the slope. Screws are like a spiral mountain road, and the more the groove is, the more effort is. The thread of the screw is a simple mechanical "spiral" application in physics, while the spiral is the deformation of the slope.
