FAN ASSEMBLY AND HEAT DISSIPATION DEVICE HAVING THE SAME

Abstract

A heat dissipation device includes a heat sink, a fan mounted on a top side of the heat sink and a fan holder connecting the heat sink with the fan. The fan includes a blade assembly and a frame enclosing the blade assembly. The fan holder includes a supporting portion engaging with the heat sink. A connecting plate extends upwardly from an edge of the supporting portion. A ridge extends angulately and downwardly from an inner surface of the connecting plate. An operating plate extends downwardly from a bottom end of the connecting plate. The operating plate is pressed inwardly or pulled outwardly to make the ridge of the connecting plate space from or engage with the frame of the fan.

Description

BACKGROUND

1. Technical Field

The present invention relates to heat dissipation devices and, particularly, to a fan assembly capable of being conveniently assembled to and disassembled from a heat sink, and a heat dissipation device having such a fan assembly and a heat sink.

2. Description of Related Art

A heat sink is usually placed in thermal contact with a heat generating electronic device such as a central processing unit (CPU), and transfers heat through conduction away from the heat generating electronic device so as to prevent over-heating of the heat generating electronic device.

Typically, a fan is mounted on a side of a heat sink by a fan holder to improve heat dissipation efficiency of the heat sink. The fan comprises a blade assembly and a frame enclosing the blade assembly. Diagonally corners of the frame define two mounting holes, respectively. Two elastic pins extend upwardly from diagonally corners of the fan holder and corresponds to the mounting holes of the frame. The elastic pins of the fan holder are pressed into the mounting holes of the frame. When the elastic pins extend through the mounting holes, the elastic pins expand and firmly contacts the frame. In that state, the fan and the fan holder are assembled together. However, it is difficult to disassemble the fan from the fan holder, and technical tools may be used. This is very time-consuming and trouble.

For the foregoing reasons, there is a need in the art for a heat dissipation device which can overcome the limitations described.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an assembled view of a heat dissipation device in accordance with an embodiment of the present disclosure, in which the heat dissipation device is mounted on a printed circuit board.

FIG. 2 is an exploded view of the heat dissipation device in FIG. 1.

FIG. 3 is an inverted view of FIG. 2.

DETAILED DESCRIPTION

Referring to FIGS. 1-2, an embodiment of a heat dissipation device comprises a heat sink 20, a fan 40 mounted on a top side of the heat sink 20 and a fan holder 30 connecting the heat sink 20 with the fan 40.

Referring to FIG. 3 also, the heat sink 20 comprises a cylindrical heat absorbing portion 21, a number of first fins 23 and a number of second fins 24 extending outwardly and radially from a periphery of the heat absorbing portion 21. The first fins 23 are divided into four groups which are equidistantly spaced from each other and oriented toward different directions by four mounting arms 26 extending evenly from the periphery of the heat absorbing portion 21. Each of the first fins 23 comprises an elongated first connecting plate 231 connected the heat absorbing portion 21 and two elongated and angled first extending plates 233 extending outwardly from the outmost end of the first connecting plate 231. The second fins 24 are divided into four groups also. Each group of the second fins 24 comprises two adjacent second fins 24 positioned between the two adjacent groups of the first fins 23. Each second fin 24 comprises an elongated second connecting plate 241 extending from the heat absorbing portion 21 and two elongated and angled second extending plates 243 extending outwardly from the outmost end of the second connecting plate 241. A height of the first connecting plate 231 is equal to that of the second connecting plate 241. Heights of the first and second extending plates 233, 243 are less than that of the heat absorbing portion 21. A width of the first connecting plate 231 is equal to that of the second connecting plate 241. A width of the first extending plate 233 is larger than that of the second extending plate 243. Tops of the first and second fins 23, 24 and a top surface of the heat absorbing portion 21 are coplanar. The bottom portion of the heat absorbing portion 21 is below bottom ends of the first and second fins 23, 24; thus a step 25 is defined at a bottom portion of the heat sink 20.

A height of the mounting arm 26 is equal to that of the first fin 23. A width of the mounting arm 26 is equal to that of the first fin 23. A thickness of the mounting arm 26 is larger than that of the first and second fins 23, 24. Each of the mounting arms 26 is sandwiched between the two adjoining second fins 24. An inner section of the mounting arm 26 and the second connecting plates 241 of the two adjoining second fins 24 are integrated, and an outer section of the mounting arm 26 is spaced from the second connecting plates 241 of the two adjoining second fins 24. An outmost end of the mounting arm 26 defines two spaced first engaging portions 261 to engage with the fan holder 30 and a second engaging portion 263 to engage with a printed circuit board 10. Each of the first engaging portions 261 is an elongated groove and extends along a height direction of the mounting arm 26. The eight first engaging portions 261 are divided into first and second groups. The first engaging portions 261, which are located at front sides of the mounting arms 26, respectively, along a clockwise direction as viewed from FIG. 2, belong to the first group. The first engaging portions 261, which are located at rear sides of the mounting arms 26, respectively, belong to the second group. The first and second groups of the first engaging portions 261 are engage with the fan holder 30. The second engaging portion 263 is positioned between the two first engaging portions 261 and has a C-shaped configuration. Four screws 50 extend through the second engaging portions 263 and engage with the printed circuit board 10 to mount the heat sink 20 on the printed circuit board 10.

The fan holder 30 is integrally formed by a plastic material and comprises an annular engaging member 31 and four supporting portions 33 extending outwardly from a top end of the engaging member 31. The four supporting portions 33 are equidistantly spaced from each other. The two adjacent supporting portions 33 are connected by a linking plate 35 which extends inwardly from an edge of the engaging member 31. The supporting portion 33 is a triangular plate and is beyond the engaging member 31. A connecting plate 331 extends upwardly from an edge of the supporting portion 33. A ridge 3312 extends angulately and downwardly from a top end of the connecting plate 331 to press the fan 40. An operating plate 333 extends downwardly from a bottom end of the connecting plate 331. The connecting plate 331, the operating plate 333 and the ridge 3312 are integrally made of elastic material. The operating plate 333 is pressed inwardly or pulled outwardly to make the ridge 3312 of the connecting plate 331 space from or engage with the fan 40. A through hole 332 is defined in the supporting portion 33 and is adjacent to a joint of the supporting portion 33 and the connecting plate 331. An elastic pin 335 extends upwardly from a top surface of the supporting portion 31 and is located at an outer side of the connecting plate 331. The pins 335 engage with the fan 40. A screw hole 339 is defined at a corner of the supporting portion 33. Four screws 60 extend through the screw holes 339 and engage with the first or second group of the first engaging portions 261 of the four mounting arms 26 of the heat sink 20 to mount the fan holder 30 on the heat sink 20. A triangular reinforcing rib 337 is formed at a bottom surface of the supporting portion 33 and connects with the engaging member 31.

The fan 40 comprises a cubical bracket 41 and a blade assembly 43 received in the bracket 41. Central portions of four corners of the bracket 41 are recessed; thus, four triangular mounting portions 412 are formed at bottom end of the bracket 41. Central portion of the mounting portion 412 defines a through hole 414 to receive the pin 335 of the fan holder 30.

In assembly, the screws 50 extend through the second engaging portions 263 of the mounting arms 26 of the heat sink 20 and engage with the printed circuit board 10 to mount the heat sink 20 on the printed circuit board 10. The engaging member 31 of the fan holder 30 encloses a top end of the heat sink 20 and the screw hole 339 of the supporting portion 33 aligns with the corresponding first engaging portion 261 of the mounting arm 26. The screws 60 extend through the screw holes 339 and engage with the first or second groups of the first engaging portion 261 to mount the fan holder 30 on the heat sink 20. The operating plates 333 of the fan holder 30 are subjected to an external force, which presses the operating plates 333 inwardly to make the connecting plates 331 run outwardly. Thereafter, the fan 40 is pressed towards the fan holder 30 until the pins 335 of the fan holder 30 extend in the through holes 414 of the mounting portions 412. Then, the external force of the operating plates 333 is released; a resilience of the operating plates 333 impels the connecting plates 331 to move towards the fan 40. As a result, the ridges 3312 of the connecting plates 331 press the top surfaces of the supporting portions 33. Therefore, the heat dissipation device is assembled completely.

In disassembly, the operating plates 333 are pressed inwardly to make the connecting plates 331 run outwardly until the ridges 3312 of the connecting plates 331 are separated from the supporting portions 33. Thereafter, the fan 40 is taken out from the fan holder 30. Thus, the fan 40 is disassembled from the fan holder 30.

It is to be understood, however, that even though numerous characteristics and advantages of the disclosure have been set forth in the foregoing description, together with details of the structure and function of the disclosure, 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 disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.

Claims

1. A fan assembly comprising:

a fan comprising a blade assembly and a frame supporting the blade assembly; and

a fan holder comprising a supporting portion, a connecting plate extending upwardly from an edge of the supporting portion, a ridge extending angulately and downwardly from a top end of the connecting plate, an operating plate extending downwardly from a bottom end of the connecting plate;

wherein the operating plate is pressed inwardly or pulled outwardly to make the ridge of the connecting plate space from or engage with the frame of the fan.

2. The fan assembly as claimed in claim 1, wherein the connecting plate and the operating plate are integrally made of an elastic material.

3. The fan assembly as claimed in claim 1, wherein a pin extends upwardly from a top surface of the supporting portion and extends through the frame of the fan.

4. The fan assembly as claimed in claim 1, wherein an engaging member connects with the supporting portion, the engaging member adapted for engaging with a heat sink.

5. The fan assembly as claimed in claim 4, wherein the engaging member is annular and the supporting portion extends outwardly from a top of the engaging member.

6. The fan assembly as claimed in claim 5, wherein a reinforcing rib is formed at a bottom of the supporting portion and connects with the engaging member.

7. The fan assembly as claimed in claim 5, wherein a plurality of supporting portions are formed at the top of the engaging member.

8. The fan assembly as claimed in claim 1, wherein a through hole is defined in the supporting portion and is adjacent to a joint of the supporting portion and the connecting plate.

9. A heat dissipation device comprising:

a heat sink;

a fan mounted on a top side of the heat sink, the fan comprising a blade assembly and a frame enclosing the blade assembly; and

a fan holder comprising a supporting portion engaging with the heat sink, a connecting plate extending upwardly from an edge of the supporting portion, a ridge extending angulately and downwardly from a top end of the connecting plate, an operating plate extending downwardly from a bottom end of the connecting plate;

wherein the operating plate is pressed inwardly or pulled outwardly to make the ridge of the connecting plate space from or engage with the frame of the fan.

10. The heat dissipation device as claimed in claim 9, wherein a pin extends upwardly from a top surface of the supporting portion and through the frame of the fan.

11. The heat dissipation device as claimed in claim 10, wherein an engaging member connects with the supporting portion, and the engaging member encloses a top end of the heat sink therein.

12. The heat dissipation device as claimed in claim 9, wherein the heat sink comprises a heat absorbing portion and a plurality of mounting arms extending outwardly and radially from a periphery of the heat absorbing portion, a screw extends through the supporting portion of the fan holder and engages with a corresponding mounting arm to mount the fan holder on the heat sink.

13. The heat dissipation device as claimed in claim 12, wherein the heat sink comprises a plurality of fins extending outwardly and radially from a periphery of the heat absorbing portion, and a bottom end of the heat absorbing portion is below bottom ends of the fins.

14. The heat dissipation device as claimed in claim 13, wherein each of the fins comprises a connecting plate connected the heat absorbing portion and two angled extending plates extending outwardly from an outmost end of the connecting plate.

15. The heat dissipation device as claimed in claim 14, wherein the fins are divided a plurality of groups and each group of the fins is sandwiched between two adjacent mounting arms.