Most electric fans do not use ball bearings. Why?

Most household electric fans do not use ball bearings, and the design life of general household appliances is about 10 years. The bearings for electric fans are low-noise oil-bearing bearings. If you use 10 years or so, there should be no problem. The ceiling fan has high power, long blades and strong wind force, but its rotation speed is slow, which is beneficial to the bearing not to refuel for many years after adding soft oil, and the rotation speed is slow and there is no noise.

The motors of floor fans and desktop fans have no ball bearings. There are oil-absorbing materials in the shaft sleeves at both ends of the rotor. Inject 3ml engine oil into the upper hole every year before use, which has good lubricity. The oil fan rotates very fast, and there is no friction sound, only the sound of blades. If bearings are used, the balls will produce noise quickly, which is not a saving problem for manufacturers. It is designed to eliminate noise.

The bearing problem is basically no lubrication, and it can only be used for one month with ordinary lubricating oil. I used to take it apart as much as possible, but now it's basically broken, because it costs tens of dollars to buy a motor, which is time-consuming and laborious. Fans have become fast-moving consumer goods, and most of the acceptable prices are within one or two hundred yuan. When the price is high, ordinary people don't believe it will be durable, and so do big brands. Many of them are OEM and need to be replaced in a year or two. Deep groove ball bearing has a small middle surface and a small friction coefficient because of the rolling of metal beads and friction caused by rolling; For other bearings, such as oil-lubricated bearings, friction is caused by sliding. After long-term use, the oil will evaporate, the bearing will be easily damaged, the friction coefficient will be large, the noise will be high in the middle and late stages, and the period will be short.

A good fan bearing has strong stability and is not easy to be damaged. Bearing mode of household motor for fan is also very important. For domestic fans with oil bearing, the oil in the bearing will evaporate and dry, and the friction coefficient will increase, which will affect the operation of the fan blades and may cause abnormal sound, low speed or even non-rotation. Rolling friction replaces the rolling friction of ball bearings. The friction coefficient is small, which eliminates the defect that the friction coefficient is easy to produce. Therefore, the operation reliability is strong and the service life is relatively long.