Air ventilation structure for D.C. brushless air fans

Abstract

An air ventilation structure for D.C. brushless air fans provides a selected number of side apertures on the side wall of the air fan casing and slot openings at the front end of the air fan rotor. Through the side apertures and slot openings, high temperature generated during the air fan operation will be carried away and air ventilation in the air fan will increase thereby increase the air fan durability.

Description

BACKGROUND OF THE INVENTION

[0001] This invention relates to an air ventilation structure for D.C. brushless air fans and particularly an air fan that has a elected number of side apertures formed on the side wall of the air fan casing and slot openings located at the front end of the rotor for carrying away high temperature generated during air fan operation and increasing air ventilation and enhancing air fan durability.

[0002] With increasing popularity of personal computers and rapid development in the computer industry, heat generation and dissipation problem incurred to various kinds of electronic elements has become a critical and important issue. Hence using D.C. brushless air fan as the main heat dissipating element is a prevailing trend and has been widely adapted in the computer industry. It has a simple structure and small size, and can rapidly resolve the heat generation and dissipation problem incurred to electronic elements.

[0003] However while the D.C. brushless air fans now available on the market may fix the heat dissipation problem for electronic elements, they cannot overcome the heat dissipation problem happened to themselves. For instance, the area between the stator and rotor is closed. It is difficult to disperse the high temperature generated in the ferrite coils of the stator. This accumulated heat energy could result in excess high temperature of the air fan and dry the lubricating oil in the bearing, and consequently cause poor lubrication effect of the bearing and dropping of air fan rotation speed. In the severe situations, it could even cause the air fan stop rotating or burn out of the ferrite coils on the stator.

[0004] There is still no effective way being found thus far to resolve the problems of D.C. brushless air fan regard to overcome its own heat dissipation, short durability and unstable function.

SUMMARY OF THE INVENTION

[0005] The primary object of this invention is to resolve the foregoing disadvantages. This structure according to this invention is to form a selected number of side apertures on the side wall of the air fan casing and slot openings at the front end of the air fan rotor. By means of this simple structure, it can carry away high temperature generated during air fan operation and increase air ventilation and significantly enhance air fan durability.

[0006] The foregoing, as well as additional objects, features and advantages of this invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 is an exploded view of this invention.

[0008] FIG. 2 is a sectional view of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0009] Referring to FIGS. 1 and 2, this invention mainly consists of a casing 1, a stator 2, a rotor 3 and a circuit board 4 (PC board). The casing 1 and stator 2 are fixedly fastened together. The circuit board (PC board) 4 is fixedly disposed on the casing 1. The rotor 3 is coupled between the stator 2 and casing 1.

[0010] On the side wall of the casing 1, a selected number of side apertures 11 are formed thereon. The side apertures 11 are opened in the radial direction. The front end of the rotor 3 against the air flow direction has a selected number of slot openings 31 formed thereon. The slot openings 31 are opened in the axial direction.

[0011] When in use, the rotor 3 rotates upon receiving electricity and being energized, the blades of the rotor 3 generate air ventilation between the rotor 3 and casing 1. Because of the slot openings 31 at the front end of the rotor 3 and the side apertures 11 on the side wall of the casing 1, the high temperature generated in the stator 2 will be carried away through the side apertures 11 and slot openings 31. Hence the temperature of the ferrite coils of the stator 2 will become lower, and air ventilation of the air fan will also increase.

[0012] Hence this invention offers a simple but effective construction which can carry the high temperature generated during air fan operation, increase air ventilation and enhance air fan durability.

[0013] The air ventilation structure for D.C. brushless air fans of this invention mainly provides a selected number of side apertures on the side wall of the air fan casing and slot openings at the front end of the air fan rotor. By means of such a construction, the problems and disadvantages happened to the conventional air fans will be resolved completely.

[0014] While the preferred embodiment of this invention has been set forth for purpose of disclosure, modifications of the disclosed embodiments of the invention as well as other embodiment thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of this invention.

Claims

1. An air ventilation structure for a D.C. brushless air fan, comprising:

a casing having a side wall which has a selected number of side apertures formed thereon;

a stator fixedly fastened to the casing;

a circuit board fixedly located on the casing; and

a rotor coupled between the stator and the casing having a selected number of slot openings formed at a front end thereof;

wherein through the side apertures and slot openings, high temperature generated during the air fan operation will be carried away and air ventilation in the air fan will increase thereby increase the air fan durability.

2. The air ventilation structure of claim 1, wherein the side apertures are opened in a radial direction.

3. The air ventilation structure of claim 1, wherein the slot openings are opened in an axial direction.