Speed refers to the number of fan blade rotations per minute, which is affected by the number of coil turns in the motor, operating voltage, number of blades, inclination, height, diameter and bearing. The speed of the cooling fan is one of the most important indicators. The speed of the cooling fan affects the performance of the fan, such as the wind speed, air volume, noise, and service life. From the definition of the fan, it can be known that the speed of the speed is proportional to the number of rotation circles. In the same time, when the cooling fan rotates quickly, the air will be quickly circulated, and a greater air volume will be formed. However, this does not mean that the performance of a high speed fan is better than that of a low speed fan. We generally choose the fan speed according to the different usage requirements, that is, different fan types.

For different scenarios that require simple air flow to improve air quality, heat dissipation in high temperature environments, and high air volume to assist the purpose, the speed of the cooling fan varies. Therefore, the selection of the speed of the cooling fan varies with the application and the ambient temperature, and there is no absolute criterion for judging. When we choose a cooling fan, the speed is usually marked with a value. The speed of the cooling fan is mainly determined by the structure of the fan itself and its components, the friction force of the bearing and the wind resistance of the Angle of the fan blade. When the fan operation is affected by external factors, the speed will often change. The main influencing factors are as follows:

I. Operating environment

Heat dissipation fans are usually used as heat sinks. When the surrounding heat increases, the fan speed increases with the heat dissipation requirement. At the same time, if the cooling fan works in a harsh environment such as high temperature or sand for a long time, the speed will slow down.

2. The operation time

When the cooling fan runs for a long time, due to the frequent exchange of air near the fan blade, dust and impurities and other substances also flow, which is easy to accumulate in the corner of the fan blade. The friction force and resistance to overcome when the fan blade runs becomes larger, resulting in the speed of the cooling fan slows down.

3. Fan component fault

The cooling fan components need to be assembled. If improper assembly leads to loose parts during operation, the speed of the cooling fan will be affected. In addition, worn fan shafts may generate debris, resulting in slow fan speed.

The speed of the fan is closely related to the quality of the fan. When the speed of the fan increases, the air volume, noise and vibration will increase correspondingly. The speed of the fan is directly related to the noise of the fan. When the speed increases, in addition to bringing more air volume, friction and vibration will increase, noise will be obvious, bearing wear, affecting the service life of the fan.