Patent Grant
7674094
The present invention relates generally to an electric fan with a rotor assembly and a bearing, and more particularly to an electric fan having a sealing lid abutting against the bearing to prevent leakage of lubricant oil and prevent the bearing from deflection.
As ICs (integrated circuits) such as computer CPUs (central processing units) are being designed to run faster and faster, more and more heat is being generated by these ICs. Electric fans are typically used to dissipate the heat generated by these ICs.
Referring to
In the related fan 90, the sealing lid 80 is manually inserted in the bottom of the sleeve 95. The force exerted to insert the sealing lid 80 is varied and not predetermined. Sometimes the force is too large, which deforms or even damages the sealing lid 80. Furthermore, the sealing lid 80 is made of rubber. When the fan 90 is operated at high speed, large amounts of heat are generated, which results in that the sealing lid 80 is prone to deformation and aging; in addition, the sealing lid 80 cannot provide an axial support to the bearing 94, whereby the bearing 94 is likely to deform and generate noise when the rotor assembly 93 rotates.
Therefore, it is desirable to provide a fan having a sealing lid which overcomes the foregoing disadvantages.
According to a preferred embodiment of the present invention, an electric fan includes a fan base, a bearing and a rotor assembly. The fan base forms a central tube receiving the bearing therein. The rotor assembly includes a fan hub, and a pivot axle rotatably joined to the bearing in the fan hub. The pivot axle pivotably extends through the bearing. A sealing lid is screwedly mounted on a bottom opening of the central tube to prevent lubricant oil contained in a bottom of the central tube from leaking. The sealing lid abuts against a bottom of the bearing to prevent the bearing from deflection.
Other advantages and novel features of the present invention will become more apparent from the following detailed description of preferred embodiment when taken in conjunction with the accompanying drawings, in which:
Many aspects of the present device can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present device. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
The fan base 10 defines a cavity 102 for receiving the rotor assembly 20 and the stator assembly 30 therein. A central tube 11 is formed at a central portion of the fan base 10. The central tube 11 has a hollow and cylindrical configuration. The bearing 40 is engagingly received in an opening (not labeled) of the central tube 11. The stator assembly 30 is attached around the central tube 11. A baffle element 110 bends from a top of a circumferential wall (not labeled) of the central tube 11 and engages with the bearing 40 so as to prevent lubricating oil from leaking from a top end of the bearing 40. The baffle element 110 comprises an annular connecting portion 111 extending perpendicularly, horizontally and inwardly from a top of the circumferential wall of the center tube 11 and a leg 112 extending perpendicularly and downwardly from an inner end of the connecting portion 111. A lubricant reservoir 14 is formed in the fan base 10 below the bearing 40 and above the sealing lid 60, which supplies the lubricant oil to the bearing 40 when the fan is operated. The sealing lid 60 is mounted on a bottom of the opening of the central tube 11. An inner surface of the bottom opening of the central tube 11 corresponding to the sealing lid 60 forms a plurality of internal threads 113.
The rotor assembly 20 comprises a generally cup-like fan hub 22 having a top wall (not labeled) and a periphery wall (not labeled) extending downwardly from a circumference of the top wall. A plurality of fan blades 21 are formed around the periphery wall of the fan hub 22. An axle seat 24 is formed on a center of the top wall. A pivot axle 23 extends perpendicularly downwards from the top wall of the fan hub 22 and has an upper portion surrounded by the axle seat 24. A first annular slot 231 positioned corresponding to a top of the bearing 40 is defined in an upper portion of the pivot axle 23 for receiving a first locking ring 50. The first locking ring 50 is sandwiched between a top of the bearing 40 and a bottom of the leg 112 of the baffle element 110. The pivot axle 23 is formed with a semispherical bottom end 230. A second annular slot 232 is defined in a lower portion of the pivot axle 23 in the vicinity of the bottom end 230 and positioned corresponding to a bottom of the bearing 40, for receiving a second locking ring 70. The first and second locking rings 50, 70 located at two opposite ends of the bearing 40 can hold the rotor assembly 20 in position in respective to an axial direction thereof, thereby preventing the rotor assembly 20 from escaping from the bearing 40. Simultaneously, the first locking ring 50 located between the top of the bearing 40 and the leg 112 of the baffle element 110 can prevent the lubricant oil from leaking from a gap between the leg 112 of the baffle element 110 and the pivot axle 23.
Referring to
The bearing 40 has a cylindrical shape, and has a cylindrical outer wall 41. A central hole 410 is defined in a central portion of the bearing 40 for receiving the pivot axle 23 therein. A plurality of evenly spaced protrusions 42 extend upwardly from a top end of the outer wall 41 for engaging with a bottom of the connecting portion 111 of the baffle element 110. A plurality of evenly spaced bulwarks 44 corresponding to the protrusions 42 are circumferentially formed on the outer wall 41 for abutting against an inner surface of the central tube 11.
Referring to
In the present invention, the sealing lid 60 is screwedly connected to the bottom of the central tube 11; as a result, the sealing lid 60 will not slide off from the fan so that a risk of leakage of the lubricant oil can be avoided. Furthermore, the sealing lid 60 abuts against the bottom of the bearing 40 and the baffle element 110 abuts against the protrusions 42 extending from the top of the bearing 40 so that a problem of a deflection of the bearing 40 can be lessened, in comparison with the related art fan when the fans are operated at high speed. Finally, a pneumatic screwdriver (not shown) which can exert a predetermined force (torque) can be used to screw the sealing lid 60 to the bottom of the central tube 11 to threadedly connect the sealing lid 60 with the internal threads 113; thus, the assembly of the sealing lid 60 with the fan can be quickly completed under a uniform quality. The assembling force exerted on the sealing lid 60 is even.
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4363631 | Wloka | Dec 1982 | A |
| 6267567 | Hsieh | Jul 2001 | B1 |
| 6400054 | Horng | Jun 2002 | B1 |
| 6726450 | Lee et al. | Apr 2004 | B2 |
| 6756714 | Alex et al. | Jun 2004 | B2 |
| 20040234398 | Hu et al. | Nov 2004 | A1 |
| 20060171826 | Wu et al. | Aug 2006 | A1 |
| 20070257571 | Hong et al. | Nov 2007 | A1 |
| Number | Date | Country |
|---|---|---|
| 492520 | Jun 2002 | TW |
| Number | Date | Country | |
|---|---|---|---|
| 20080063527 A1 | Mar 2008 | US |
