1. Field of the Invention
The present invention relates generally to a fan anti-corrosion structure, which is able to protect the circuit board from the corrosion of the moisture and the salt fog. The fan anti-corrosion structure is formed without using any mold. Therefore, the cost of the mold is saved to lower the manufacturing cost.
2. Description of the Related Art
A conventional cooling fan generally includes a fan frame body, a bearing cup seat, a fan impeller, a circuit board and a stator assembly.
The cooling fan has been more and more widely applied to various fields including CPU of an electronic apparatus, server, power supply, communication chassis, communication base station, etc. In some cases, the cooling fan is used in a severe environment such as a moist environment or a salt fog environment. In the case that the cooling fan is not provided with a waterproof and anti-corrosion structure, the moisture and salt fog will infiltrate into the stator assembly and the bearing or even the circuit board to corrode these components. As a result, the lifetime of the cooling fan will be shortened.
A sealant filling technique has been disclosed to solve the above problem. Referring to
However, due to the cost of the mold, the total manufacturing cost of the cooling fan is increased. Moreover, after repeatedly used several times, the mold must be replaced with a new one. This also leads to increase of the total manufacturing cost. In addition, the electronic components of the circuit board 12 are enclosed by the anti-corrosion material 14. As a result, the heat dissipation effect of the circuit board 12 is deteriorated. This will lead to rise of temperature of the circuit board.
According to the above, the conventional fan anti-corrosion structure has the following shortcomings:
It is therefore a primary object of the present invention to provide a fan anti-corrosion structure, which is able to protect the circuit board from the corrosion of the moisture and the salt fog. The fan anti-corrosion structure is formed without using any mold. Therefore, the cost of the mold is saved to lower the manufacturing cost
It is a further object of the present invention to provide the above fan anti-corrosion structure, which can enhance the heat dissipation efficiency of the fan.
To achieve the above and other objects, the fan anti-corrosion structure of the present invention includes a base seat, a circuit board, a stator assembly and at least one coating unit.
The base seat has a sidewall and a bearing cup extending from the base seat. At least one rest face extending from the sidewall toward the bearing cup. The circuit board is fitted around the bearing cup and disposed on the rest face. At least one electronic component is disposed on one face of the circuit board, which face is proximal to the base seat. The electronic component is disposed in the closed space. The stator assembly includes multiple silicon steel sheets. The stator assembly is fitted around the bearing cup and disposed on the circuit board. The coating unit is coated on the other face of the circuit board, which face is distal from the base seat. At least one electronic component is disposed on the other face of the circuit board, which face is distal from the base seat. The coating unit is also coated on the electronic component. The circuit board is protected from the corrosion of the moisture and the salt fog by the coating unit and the closed space. Also, the fan anti-corrosion structure is formed without using any mold so that the cost of the mold for forming the coating unit is saved to lower the manufacturing cost.
According to the above, the present invention has the following advantages:
The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein:
Please refer to
The circuit board 3 is formed with a central hole 31. Via the central hole 31, the circuit board 3 is fitted around the bearing cup 22 and disposed on the rest face 211. The circuit board 3 has a configuration corresponding to the rest face 211. When the circuit board 3 is disposed on the rest face 211, a closed space 213 is defined between one face of the circuit board 3 and the base seat 2. In addition, at least one passage 212 is defined between the circuit board 3 and the sidewall 21 of the base seat 2. At least one electronic component 32 is disposed on one face of the circuit board 3, which face is proximal to the base seat 2. The electronic component 32 is disposed in the closed space 213. At least one electronic component 32 is disposed on the other face of the circuit board 3, which face is distal from the base seat 2.
The stator assembly 4 includes multiple silicon steel sheets 41, a first support 42 and a second support 43. The stator assembly 4 is fitted around the bearing cup 22. The first support 42 is disposed on the circuit board 3. The second support 43 extends to the base seat 2 into contact with the circumference of the central hole 31 of the circuit board 3 to define the closed space 213.
The coating unit 5 is coated on the other face of the circuit board 3, which face is distal from the base seat 2, and coated on the electronic component 32. The coating unit 5 is also disposed in the passage 212 and coated on an end of the first support 42, which end is disposed on the circuit board 3. Two sides of the coating unit 5 are restricted between the sidewall 21 and the second support 43. In this embodiment, the coating unit 5 is made of anti-corrosion material. In the case that the fan is used in an environment such as a salt fog environment that will corrode the circuit board 3, the circuit board 3 and the electronic components 32 disposed on two faces of the circuit board 3 are respectively protected from the corrosive environment by the closed space 213 and the coating unit 5. Alternatively, the coating unit 5 can be directly coated on the circuit board 3 and restricted between the sidewall 21 and the second support 43. In this case, the cost of the mold for forming the coating unit 5 can be saved. According to the above arrangement, the circuit board 3 is protected from the corrosion of the moisture and the salt fog by the coating unit 5 and the closed space 213. Also, the cost of the mold for forming the coating unit 5 can be saved to lower the manufacturing cost.
The present invention has been described with the above embodiments thereof and it is understood that many changes and modifications in the above embodiments can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims.