Why are the fan blades loose?

The fan blades of aircraft engines may appear loose, but in reality, they are a scientific design. The connection between the fan blade and the blade disc is achieved through a mortise and tenon structure, which is called the "fir tree type" mortise and tenon. There is a gap between its tenon and mortise, which facilitates the tenon to slide freely within a certain range. When the fan rotates slowly, under the action of gravity, each blade will slide towards the axis when approaching the twelve o'clock position, and will slide out in the opposite direction of the axis when approaching the six o'clock position. The main reason for this design is to reduce vibration and maintain the dynamic balance of the blades.

The unit is designed for unsupervised public use: controls are recessed or shielded, moving parts are enclosed, and the interface is operable by a child of about six with no instruction. Where a screen is used, the language can be switched without changing the hardware, and the content can be replaced on site.

1. Centrifugal force: When an object is in circular motion, there needs to be a certain force acting as centripetal force, but if the provided force is not enough to act as centripetal force, centrifugal phenomenon will occur. In terms of effect, an object appears to be subjected to an opposite force, which we often refer to as' centrifugal force 'when it appears to exist but does not actually exist. two Mortise and tenon structure: The mortise and tenon structure does not require the use of metal connectors. The protruding rod head and the recessed mortise and tenon eye are tightly interlocked through concave convex buckles. It is capable of bearing weight on its own, lightweight yet sturdy. The most basic principle of vertebral structure is the lever principle. In the vertebral mortise structure, the combination of mortise and tenon creates two opposing forces on the wood, one is the pressure of the mortise and tenon, and the other is the tension on the rivet. These two reactive forces form an equilibrium state that stabilizes the entire structure.