What is the noise when the electric fan rotates?

The noise of the fan is getting louder and louder, because the bearing hole of the fan is worn out because of lack of oil. The clearance between the shaft and bearing of the fan is too large, and the axial movement clearance of the fan is too large, so the fan blades can move back and forth by several millimeters. After the fan rotates, it moves axially, and the rotating plane of the fan blade is also shaking, which not only aggravates the wear, but also produces a lot of noise.

principle of operation

In addition, low-power motors such as DC motors and DC brushless motors are more and more widely used in small electric fans.

When the electric fan is working (assuming that there is no heat transfer between indoor and outdoor), the indoor temperature will not decrease, but will increase. Let's analyze the reasons for the temperature rise: when the electric fan is working, because there is current passing through the coil of the electric fan, the wires are resistive, which will inevitably give off heat and the temperature will naturally rise.

But why do people feel cold? Because there is a lot of sweat on the surface of human body, indoor air will flow when the electric fan works, so it can promote the rapid evaporation of sweat, and "evaporation needs to absorb a lot of heat", people will feel cool.