US20080232961A1

US20080232961A1 - Fan and fan frame thereof

Info

Publication number: US20080232961A1
Application number: US12/023,967
Authority: US
Inventors: Cheng-Hung Lin; Chao-Wen Lu
Original assignee: Delta Electronics Inc
Current assignee: Delta Electronics Inc
Priority date: 2007-03-23
Filing date: 2008-01-31
Publication date: 2008-09-25
Also published as: TW200839493A; TWI342482B

Abstract

A fan frame of a fan includes a main body, a base and at least one connecting element. The main body has at least one mounting portion and at least one auxiliary passage, which are not communicated with each other. A main passage is disposed in the main body, and the auxiliary passage is obliquely communicated with the main passage from the upper part of the main body. The base is disposed in the central portion of the main body. The connecting element is disposed between the main body and the base. A fan including such fan frame is also disclosed.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This Non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 096110082, filed in Taiwan, Republic of China on Mar. 23, 2007, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of Invention
The invention relates to a fan and a fan frame thereof, and, in particular, to a fan with an auxiliary passage and a fan frame thereof.
2. Related Art
As electronic products have better performance, higher operating frequencies, faster speeds and smaller sizes, their temperature also becomes higher. This leads to instability and affects their reliability and lifetime. Therefore, heat dissipation has become an important issue when designing new electronic products. Fans are common heat-dissipating devices used in electronic products.
A conventional fan includes a fan frame, an impeller and a motor. The impeller and the motor are disposed in the fan frame. The motor is connected to the impeller for driving it to rotate. As shown in FIG. 1, a conventional fan frame 1 has a main body 11, a base 12 and several ribs 13. Both ends of each rib 13 are connected to the main body 11 and the base 12, respectively. The corners of the main body 11 are formed with several screw holes 111. The fan frame 1 is then fixed to any external system via the screw holes 111.
In addition to the original main passage 112 of the main body 11, several auxiliary passages 113 are also provided around the main body 11 for guiding air to merge with the airflow in the main passage 112, thereby increasing the air intake.
FIG. 2 is a cross-sectional view of FIG. 1 along the line A-A. An auxiliary airflow Aa is guided via the auxiliary passage 113 into the main passage 112 and merges with a main airflow Am in the main passage 112. However, when the auxiliary airflow Aa enters, it firstly passes the screw 114 disposed in the screw hole 111 before being guided through the auxiliary passage 113 into the main passage 112 because the screw hole 111 has a position lower than the auxiliary passage 113. As the screw 114 has an unsmooth curved surface, noises are produced when air flows by. In addition, the auxiliary airflow Aa merges with the main airflow Am at an approximately perpendicular angle. This causes turbulence or vortices that decrease the performance of the fan.

SUMMARY OF THE INVENTION

In view of the foregoing, the present invention is to provide a fan with better performance and smaller noises and the fan frame thereof.
To achieve the above, the present invention discloses a fan frame including a main body, a base and at least one connecting element. The main body has at least one mounting portion and at least one auxiliary passage, which are not communicated with each other. A main passage is disposed in the main body. The base is disposed at the central portion of the main body, and the connecting element is disposed between the main body and the base.
To achieve the above, the present invention discloses a fan including a fan frame having a main body, a motor and an impeller. The main body has at least one mounting portion and at least one auxiliary passage, which are not communicated with each other. A main passage is disposed in the main body. The motor is disposed in the main body, and the impeller is disposed in the fan frame and connected to the motor so that the motor drives the impeller to rotate.
As mentioned above, the fan and the fan frame of the present invention utilize the auxiliary passages to increase the air intake. The auxiliary passages and the mounting portions of the main body are not communicated. Therefore, the airflow guided by the auxiliary passages is not affected by the mounting portions. Compared with the related art, the present invention can increase the performance of the fan and decrease noises when air flows through the mounting portions. In addition, the auxiliary passages are obliquely communicated with the main passage from the upper part of the main body. Therefore, the auxiliary airflow merges more smoothly with the main airflow without turbulence or vortices.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description and accompanying drawings, which are given for illustration only, and thus are not limitative of the present invention, and wherein:

FIG. 1 is a schematic illustration of a conventional fan frame;

FIG. 2 is a cross-sectional illustration of the fan frame in FIG. 1 along the line A-A;

FIG. 3 is a schematic illustration of a fan frame according to an embodiment of the present invention;

FIG. 4 is a cross-sectional illustration of the fan frame in FIG. 3 along the line B-B;

FIG. 5 is a diagram showing the comparison of the performance curves and noise curves of using the fan frame of the present invention and the conventional fan frame; and

FIG. 6 is a schematic view of a fan according to the embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.
As shown in FIG. 3, a fan frame 2 according to an embodiment of the present invention includes a main body 21, a base 22 and at least one connecting element 23. In this embodiment, the fan frame 2 has several connecting elements 23. The base 22 is disposed in the central portion of the main body 21. Both ends of each connecting element 23 are respectively connected to the main body 21 and the base 22. The connecting elements 23, the base 22 and the main body 21 are integrally formed as a single unit.
The main body 21 has at least one mounting portion 211. In this embodiment, the main body 21 has four through holes as the mounting portions 211. A main passage 212 and at least one auxiliary passage 213 are disposed in the main body 21. In this embodiment, the main body 21 has four auxiliary passages 213 disposed at the corners of the main body 21. Alternatively, the auxiliary passages 213 can be formed on the sides of the main body 21, or both at the corners and on the sides of the main body 21 as well. The auxiliary passages 213 are disposed on the sides of the mounting portions 211. The auxiliary passages 213 are not communicated with the mounting portions 211. Such independent installations forbid the airflow from being guided by the mounting portions into the auxiliary passages 213. That is, the airflow is not influenced by the mounting portions 211 so that noises can be minimized.
FIG. 4 is a cross-sectional view of FIG. 3 along the line B-B. The auxiliary passage 213 is communicated with the main passage 212 at an oblique angle θ from the upper part 214 of the main body 21. In practice, the confluence of the auxiliary passage 213 and the main passage 212 can be located between ⅓ and ½ of the main body 21 along an air intake direction, so that the airflow intake is increased. The oblique angle θ between the auxiliary passage 213 and the main passage 212 is between 20 and 50 degrees. More preferably, the oblique angle θ is between 25.5 and 42.5 degrees. When the auxiliary airflow Ba is guided through the auxiliary passages 213 into the main passage 212, it merges with a main airflow Bm in the main passage 212 to form a smooth flow field without turbulence or vortices. This increases the efficiency of the merging airflow and thus the performance of the fan.
Referring to FIG. 5, the fan frame 2 of the present invention and the conventional fan frame 1 are analyzed experimentally. The performance curves and the noise curves show the following features. The wind pressure and wind flux output by the present invention are both higher than the prior art. Moreover, the stall region is delayed. Therefore, when the fan is disposed in a system with higher resistance, less noise is produced. Overall, the noise curve of the present invention is better than the prior art, which means that the noise produced by the fan frame of the present invention is smaller.
As shown in FIG. 6, a fan 3 according to the embodiment of the present invention includes a fan, frame 30, a motor 34 and an impeller 35. The fan frame 30 has a main body 31, a base 32 and at least one connecting element 33. The main body 31 has at least one mounting portion (not shown), a main passage 312 and at least one auxiliary passage 313. The fan frame 30 in this embodiment has a similar structure and functions as the previous-mentioned fan frame 2, so the description thereof is omitted.
The motor 34 is disposed in the main body 31. The motor 34 has a stator 341 and a rotor 342. The stator 341 is mounted on an axial tube part 321 of the base 32 and electrically connected with a circuit board 36. The rotor 342 has a shaft 3421, a magnetic element 3422 and a shell 3423. The shaft 3421 goes through the axial tube part 321 and is supported by at least one bearing 37. The magnetic element 3422 is connected to the inner circumference of the shell 3423.
The impeller 35 includes a hub 351 and several blades 352. The hub 351 is connected to the shell 3423. The blades 352 are connected to the outer circumference of the hub 351. The impeller 35 is connected with the shaft 3421 and the shaft 3421 is within the axial tube part 321.
The motor 34 drives the impeller 35 to rotate and draws in at least one main airflow Bm via the main passage 312 and at least one auxiliary airflow Ba via the auxiliary passages 313 into the fan 3. Since the auxiliary passages 313 and the mounting portions (not shown) are not communicated, the airflow is not guided by the mounting portions back into the auxiliary passages 313 due to the independent structure. Therefore, the mounting portions (not shown) are prevented from altering the airflow and producing noises.
Furthermore, the auxiliary passages 313 are communicated with the main passage 312 at an oblique angle θ from the upper part 314 of the main body 31, thereby increasing the airflow intake. When the auxiliary airflow Ba is guided by the auxiliary passage 313 into the main passage 312, it merges with the main airflow Bm in the main passage 312 to form a smooth flow field without turbulence or vortices. This increases the efficiency of the merging airflow and thus the performance of the fan.
In summary, the fan and fan frame of the present invention utilize the auxiliary passages to increase the air intake. The auxiliary passages and the mounting portions of the main body are not communicated. Therefore, the airflow guided by the auxiliary passages is not affected by the mounting portions. Compared with the related art, the present invention can increase the performance of the fan and decrease noises when air flows through the mounting portions. In addition, the auxiliary passages are obliquely communicated with the main passage from the upper part of the main frame. Therefore, the auxiliary airflow merges more smoothly with the main airflow without turbulence or vortices.
Although the present invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the present invention.

Claims

1. A fan frame, comprising:

a main body comprising at least one mounting portion and at least one auxiliary passage, wherein a main passage is disposed in the main body, and the auxiliary passage is not communicated with the mounting portion.

2. The fan frame of claim 1, further comprising a base disposed in a central portion of the main body and at least one connecting element disposed between the main body and the base.

3. The fan frame of claim 2, wherein the connecting element, the base and the main body are integrally formed as a single unit.

4. The fan frame of claim 1, wherein the auxiliary passage is disposed at a corner and/or a side of the main body.

5. The fan frame of claim 1, wherein the auxiliary passage is obliquely communicated with the main passage with an oblique angle.

6. The fan frame of claim 5, wherein the oblique angle is between 20 and 50 degrees.

7. The fan frame of claim 1, wherein the auxiliary passage is disposed on a side of the corresponding mounting portion and the mounting portion is located at a corner of the main body.

8. The fan frame of claim 1, wherein a confluence of the auxiliary passage and the main passage is located between ⅓ and ½ of the main body along an air intake direction.

9. The fan frame of claim 1, wherein the mounting portion is a through hole.

10. The fan frame of claim 1, wherein

the auxiliary passage is obliquely communicated with the main passage from an upper part of the main body.

11. A fan, comprising:

a fan frame comprising a main body, wherein the main body comprises at least one mounting portion and at least one auxiliary passage, a main passage is disposed in the main body and the auxiliary passage is not communicated with the mounting portion;

a motor disposed in the fan frame; and

an impeller disposed in the fan frame and connected to the motor so that the motor drives the impeller to rotate.

12. The fan of claim 11, wherein the fan frame further comprises a base disposed at a central portion of the main body, and at least one connecting element disposed between the main body and the base.

13. The fan of claim 12, wherein the connecting element, the base and the main body are integrally formed as a single unit.

14. The fan of claim 11, wherein the auxiliary passage is disposed at a corner and/or a side of the main body.

15. The fan of claim 11, wherein the auxiliary passage is obliquely communicated with the main passage with an oblique angle.

16. The fan of claim 15, wherein the oblique angle is between 20 and 50 degrees.

17. The fan of claim 11, wherein the auxiliary passage is disposed on a side of the corresponding mounting portion, and the mounting portion is located at a corner of the main body.

18. The fan of claim 11, wherein a confluence of the auxiliary passage and the main passage is located between ⅓ and ½ of the main body along an air intake direction.

19. The fan of claim 11, wherein the mounting portion is a through hole.

20. The fan of claim 11, wherein the auxiliary passage is obliquely communicated with the main passage from an upper part of the main body.