What problems will be encountered in the design and use of miniature cooling fans
The solution to the wind noise of the miniature cooling fan is the angle, shape, and resistance of the fan blades in the design section. The design involves some fine work, dynamics, mechanics, electronics and other fields. There are currently no experts and supporting equipment in this area in mainland China. Most of them are anti-sunlight Japanese or Taiwanese cooling fans with the same shape. The noise of the miniature cooling fan we are talking about here is as follows Two types: one mechanical noise and two wind noise of the cooling fan. To solve the mechanical noise of the miniature cooling fan, we must start with the material and assembly of the cooling fan. The following reasons will cause the cooling fan to be loud. 1. The induction IC touches the fan blade magnetic strip of the miniature cooling fan and produces frictional sound 2. The motor component of the miniature cooling fan-the coil is ground to the fan blade 3. The assembly structure size is wrong, and the bearing grinding ring 4. Bearing The material of the shaft core will produce noise itself. 1. According to the air supply form (1) Axial flow cooling fan The blades of the axial flow cooling fan push air to flow in the same direction as the shaft. The impeller and propeller of the axial flow fan are a bit similar. When it is working, the flow direction of most of the airflow is parallel to the shaft, in other words along the axis. When the inlet airflow is free air with zero static pressure, the power consumption of the axial flow cooling fan is very low. When operating, the power consumption will increase with the increase of the airflow back pressure. Axial-flow cooling fans are usually installed in the cabinet of electrical equipment, and sometimes integrated on the motor. Because the axial-flow cooling fan has a compact structure, it can save a lot of space and is easy to install, so it is widely used. Its characteristics: high flow rate, medium wind pressure. (2) Blower (centrifugal cooling fan) When the centrifugal cooling fan works, the blades push the air to flow in the direction perpendicular to the shaft (ie radial), the air intake is along the axial direction, and the outlet air is perpendicular to the axial direction. In most cases, the cooling effect can be achieved by using an axial cooling fan. However, sometimes if the airflow needs to be rotated by 90 degrees or when a larger wind pressure is required, a centrifugal cooling fan must be used. Strictly speaking, fans are also centrifugal cooling fans. Its characteristics: limited flow rate, high wind pressure.
