The service life of the cooling fan is decided by the bearing, which is divided into two kinds:

Oily bearing

Sliding friction sleeve. Lubricating oil is used as lubricant and drag reducer in the sleeve of the blade core.

Ball bearing

In the form of rolling friction, several small steel balls in the bearing rotate around the shaft core, so the friction force is very small, and there is no oil leakage problem.

Advantages of oil bearing: low noise, not suitable for long-term operation

Ball bearing advantages: stable operation, suitable for long-term operation, long service life.