How to make a waterproof DC cooling fan thoroughly

We often hear about waterproof DC fans, but according to different waterproof requirements, there are IP5X, the low-requirement is called moisture-proof, and the high-requirement waterproof has the use of potting and sealing PCB, vacuum coating and other processes, but these are actually not thorough. As shown in the figure below, we can’t see where the motor is from the picture. After the motor is completely sealed, only one middle tube is left, so whether it is immersed in water or impacted by water, it will not affect Motor, except for the motor, the entire fan has only the shaft core and the bearing. The shaft core can pass the salt spray test. Therefore, we only have to make the material of the bearing waterproof.