Base for a heat-dissipating fan motor

A base for a heat-dissipating fan motor includes a plate member made of metal, a coupling barrel made of plastic, and an outer case made of plastic. The plate member is formed with at least one positioning leg and at least one air inlet hole. The plate member has a motor-confronting side, and the positioning leg extends inclinedly and protrudes from the motor-confronting side. The coupling barrel is adapted for coupling with the heat-dissipating fan motor, and has a closed-barrel end that has the positioning leg embedded therein, and an open-barrel end opposite to the closed barrel end. The outer case is connected to the plate member, cooperates with the coupling barrel to form a motor-receiving space, and is formed with an air outlet hole.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Taiwanese Application No. 097109317, filed Mar. 17, 2008, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a base for a motor, more particularly to a base for a heat-dissipating fan motor used in portable electronic devices.

2. Description of the Related Art

Referring toFIGS. 1 and 2, a conventional base6for a heat-dissipating fan motor6used in portable electronic devices, such as a notebook computer, includes an outer case61made of plastic and formed by injection molding, and a coupling barrel62made of metal, riveted to the outer case61, and adapted for coupling with the heat-dissipating fan motor. The outer case61includes a base plate611riveted to the coupling barrel62and formed with a plurality of air inlet holes612, and a case body613which extends integrally from the base plate611and which cooperates with the base plate611to define an air outlet holes610. The coupling barrel62is shaped using a lathe (not shown).

Some of the disadvantages of the conventional base6for a heat-dissipating fan motor are as follows:

1. Because the coupling barrel62and the outer case61are interconnected by riveting, connection between the coupling barrel62and the outer case61is prone to loosen after a period of use.

2. Since a lathe is required to machine the coupling barrel62, the manufacturing cost of the base6is relatively high.

3. In order for the base plate611of the outer case61to have sufficient strength, the thickness of the base plate611must be at least 1.2 millimeters, thereby resulting in a relatively large volume of the base6, which in turn results in a corresponding increase in the volume of the portable electronic device that incorporates the base6for a heat-dissipating fan motor.

SUMMARY OF THE INVENTION

Therefore, the object of the present invention is to provide a base for a heat-dissipating fan motor that can overcome at least one of the above drawbacks of the prior art.

According to this invention, a base for a heat-dissipating fan motor includes a plate member made of metal, a coupling barrel made of plastic, and an outer case made of plastic. The plate member is formed with at least one positioning leg and at least one air inlet hole. The plate member has a motor-confronting side, and the positioning leg extends inclinedly and protrudes from the motor-confronting side. The coupling barrel is adapted for coupling with the heat-dissipating fan motor, and has a closed-barrel end that has the at least one positioning leg embedded therein, and an open-barrel end opposite to the closed barrel end. The outer case is connected to the plate member, cooperates with the coupling barrel to form a motor-receiving space, and is formed with an air outlet hole.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring toFIGS. 3,4, and5, the preferred embodiment of a base according to the present invention is suitable for a heat-dissipating fan motor1, and is shown to include a plate member2made of metal, a coupling barrel3made of plastic, and an outer case4made of plastic.

The plate member2is formed by stamping, has a motor-confronting side211that confronts the heat-dissipating fan motor1, and includes a planar portion22and a protruding portion21that is surrounded by the planar portion22and that projects relative to the planar portion22in a direction away from the motor-confronting side211. The protruding portion21is formed with a through-hole23, and a plurality of positioning legs24that extend inclinedly from a periphery of the through-hole23and that protrude from the motor-confronting side211. In this embodiment, there are four positioning legs24that are equiangularly spaced apart from each other. Preferably, each positioning leg24forms an angle α that ranges from 95 degrees to 175 degrees relative to the motor-confronting side211of the protruding portion21. In this preferred embodiment, each positioning leg24forms an angle α that is 135 degrees relative to the motor confronting side of the protruding portion21. Since the number of the positioning legs24can vary to suit a desired coupling strength between the plate member2and the coupling barrel3, one, two or three positioning legs24can be used in other embodiments of the invention. The planar portion22is formed with a plurality of air inlet holes25that surround the protruding portion21, and a plurality of ribs26each of which is elongated, projects from the motor-confronting side211, and is disposed between an adjacent pair of the air inlet holes25. The ribs26serve to reinforce connections between the planar portion22and the protruding portion21to resist deformation. The planar portion22is further formed with a plurality of arch-shaped projecting ears27that project from the motor-confronting side211. The arch-shaped projecting ears27can be solid or hollow, and serve to increase contact area between the plate member2and the outer case4, thereby enhancing structural connection between the outer case4and the plate member2. The arch-shaped projecting ears27are hollow in this embodiment, as best shown inFIG. 6.

The coupling barrel3is formed by injection molding, is adapted for coupling with the heat-dissipating fan motor1, and includes a barrel wall31defining an installation hole30and having a closed-barrel end311and an open-barrel end312. The closed-barrel end311has the positioning legs24of the plate member2embedded therein. The installation hole30has a large-diameter section301at the open-barrel end312and a small-diameter section302at the closed-barrel end311. The small-diameter section302is in spatial communication with the large-diameter section301, and has a diameter smaller than that of the large-diameter section301.

The outer case4is connected to the plate member2and cooperates with the coupling barrel3to form a motor-receiving space40for receiving the heat-dissipating fan motor1. The outer case4includes a case body41that has the engaging structures221and the arch-shaped projecting ears27embedded therein and that is formed with an air outlet hole43, and a cover body42that extends integrally from the case body41and that covers one side212of the planar potion22opposite to the motor-confronting side211without blocking the air-inlet holes25.

Some of the advantages of the base for a heat-dissipating fan motor1according to this invention are as follows:

1. Embedding engagement of the positioning legs24with the closed-barrel end311of the coupling barrel3results in a stronger connection compared to the riveting connection between the outer case61and the coupling barrel62in the prior art.

2. The plate member2is formed by stamping, whereas the coupling barrel3and the outer case4are formed by injection molding. Compared to the prior art where the outer case61and the coupling barrel62are produced by injection molding and lathe machining, respectively, the manufacturing cost of the base of this invention is lower.

3. Due to the arrangement of the cover body42that covers the side212of the planar potion22of the plate member2, the combined thickness of the cover body42and the planar portion22can be less than 1.2 millimeters while achieving sufficient strength. The minimum combined thickness of the planar portion22and the cover body42can be as small as 0.4 millimeter, thereby effectively reducing the volume of the base for a heat-dissipating fan motor1according to this invention.