When it comes to active cooling devices, fan plays an important role. Fan is a complex component which is constructed by various parts. Today we focus on the most significant part – Internal structure.
How does a fan work? It works when its impeller rotates. Take DC fan for instance, the center of its impeller has a rubber magnet which creates its own magnetic field. Copper coil on the motor generates another magnetic field. Through attraction and repulsion in two magnet fields, it rotates the impeller. DC fan is connected with an external power supply through brushes. Unlike DC fan, AC fan is supplied with its own alternating current to produce a magnetic field. When frequency speeds up, it rotates faster. However, the frequency should be monitored as it may cause malfunction.
Now, let’s introduce some critical component parts of the fan.
– Fan impeller and frame (housing):
Blades are the main part of fan impeller. The number of blades should be odd, otherwise, it will result in broken blades. Materials used for DC fan Impeller and frame are PC, PBT or Aluminum. Instead of AC fan, both impeller and frame are made of mainly Aluminum.
– Bearing
Bearing system and the working environment decide the main concern of fan’s life expectancy. Zaward has three bearing systems. The following table lists the bearing types and their life expectancy under 40°C and 15~65 R.H.
