US20030124000A1

US20030124000A1 - Heat dissipation fan

Info

Publication number: US20030124000A1
Application number: US10/028,676
Authority: US
Inventors: Po-Jen Shih; Tai-Ying Lu
Original assignee: Ideal Elethermal Inc
Current assignee: Ideal Elethermal Inc
Priority date: 2001-12-28
Filing date: 2001-12-28
Publication date: 2003-07-03

Abstract

A heat dissipation fan includes a fan blade body having a shaft mounted thereon; an inner assembly installed within the fan blade body, the inner assembly comprises an iron casing, a ring-shaped permanent magnet installed inside the iron casing, a stator bobbin with the winding of a coil thereof, and a sleeve installed in the center of the stator bobbin, and within the sleeve there are mounted a ball bearing and a lubricating bearing under the ball bearing, and wherein an upper end of the ball bearing abuts against an O-ring and a lower end of the lubricating bearing abuts against a C-type clamping ring, and wherein a lower end of the sleeve is securely mounted on a circuit board and a base; and a magnetic device installed on the base in a position corresponding to a lower end of the shaft to attract the shaft.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a heat dissipation fan, and more particularly, to a heat dissipation fan having an additional magnetic device to reduce noise and prolong the life of the heat dissipation fan. This invention features this additional magnetic device that permits inverse or declined operations of this heat dissipation fan without affecting the total height of the fan. The magnetic device also interacts with the ball bearing and C-type clamping ring installed on the shaft of this heat dissipation fan

2. Description of the Prior Art

FIG. 1 and FIG. 2 illustrate a prior art

heat dissipation fan

20. As shown in FIG. 1 and FIG. 2, the prior art heat dissipation fan 20 includes a fan blade body 7. A chamber 71 is formed in the fan blade body 7. A shaft 72 is fixed at the center of the fan blade body 7. An inner assembly 8 is fittingly mounted within the chamber 71. The shaft 72 is inserted in the inner assembly 8. The fan blade body 7 can rotate due to the interaction between the components installed in the inner assembly 8. Typically, the inner assembly 8 includes an iron casing 81, a ring-shaped permanent magnet 82 installed inside the iron casing 81 to be a rotor, a stator bobbin 84 with the winding of a coil 83 thereof, and a copper sleeve 85 installed in the center of the stator bobbin 84. Within the sleeve 85 there are mounted a ball bearing 86 and a lubricating bearing 87 under the ball bearing 86. The upper end of the ball bearing 86 abuts against an O-ring 88 and the lower end of the lubricating bearing 87 abuts against a C-type clamping ring 89. The lower end of the sleeve 85 is securely mounted on a circuit board 201 and a base 202.

However, the prior art

heat dissipation fan

20 encounters several problems. First, when assembling the prior art heat dissipation fan 20, a gap is formed between the iron casing 81 and the fan blade body 7. This results in the movement of the fan blade body 7 along the axis of the shaft 72, thereby changing the total height of the fan during inverse or declined operations. Another shortcoming of the prior art heat dissipation fan 20 is that rollers installed in the ball bearing 86 cannot roll in the same level, and hence the life of the heat dissipation fan 20 is limited. In addition, the irregular rolling of the rollers in the ball bearing 86 generates aggravating noise. Further, during the inverse operation of the heat dissipation fan 20, the C-type clamping ring 89 mounted on the free end of the shaft 72 may contact the lubricating bearing 87. The result is friction between the C-type clamping ring 89 and the lubricating bearing 87, and thus deteriorates the noise problem and of the fan.

To eliminate the weaknesses of the above conventional heat dissipation fan, the subject inventor has devoted extended efforts in intensive research and experiments, and has finally developed and designed the improved fan structure of this invention.

SUMMARY OF THE INVENTION

The primary object of the present invention is to provide an improved structure for radiating fans, relating primarily to an additional magnetic device installed in the fan that is specially applied to electronic instruments and computers.

Another objective of this invention is to provide an improved heat dissipation fan with a magnetic device that can interact with the shaft and hence permits inverse or declined operations without affecting the total height of the fan.

Still another objective of this invention is to provide an improved heat dissipation fan that has prolonged lifetime and reduced noise by the aid of an additional magnetic device. The magnetic device interacts with the C-type clamping ring and keeps it from contacting the lubricating bearing during operations.

Still another objective of this invention is to provide a low-noise cooling fan having a magnetic device that can provide magnetic forces to attract the shaft and rollers installed in the ball bearing. The rollers can rotate in the same level, thereby prolonging life of the fan and reducing noise.

According to the claimed invention, the heat dissipation fan includes a fan blade body having a shaft mounted thereon; an inner assembly installed within the fan blade body, wherein the shaft is inserted in the inner assembly, the inner assembly comprises an iron casing, a ring-shaped permanent magnet installed inside the iron casing, a stator bobbin with the winding of a coil thereof, and a sleeve installed in the center of the stator bobbin, and within the sleeve there are mounted a ball bearing and a lubricating bearing under the ball bearing, and wherein an upper end of the ball bearing abuts against an O-ring and a lower end of the lubricating bearing abuts against a C-type clamping ring, and wherein a lower end of the sleeve is securely mounted on a circuit board and a base; and a magnetic device installed on the base in a position corresponding to a lower end of the shaft to attract the shaft.

It is to be understood that both the forgoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed. Other advantages and features of the invention will be apparent from the following description, drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 and FIG. 2 illustrate a prior art heat dissipation fan. [0013]
FIG. 3 is an exploded diagram of the heat dissipation fan in accordance with the preferred embodiment of this invention. [0014]
FIG. 4 illustrates a cross sectional view of the heat dissipation fan according to this invention.[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Please refer to FIG. 3 and FIG. 4. FIG. 3 is an exploded diagram of the [0016] heat dissipation fan 10 in accordance with the preferred embodiment of this invention. FIG. 4 illustrates a cross sectional view of the heat dissipation fan 10 according to this invention. As shown in FIG. 3 and FIG. 4, the heat dissipation fan 10 includes a fan blade body 1. A chamber 11 is formed in the fan blade body 1. A shaft 12 is fixed at the center of the fan blade body 1. An inner assembly 2 is fittingly mounted within the chamber 11. The shaft 12 is inserted in the inner assembly 2. The fan blade body 1 can rotate due to the interaction between the components installed in the inner assembly 2. The inner assembly 2 includes an iron casing 21, a ring-shaped permanent magnet 22 installed inside the iron casing 21 to be a rotor, a stator bobbin 24 with the winding of a coil 23 thereof, and a copper sleeve 25 installed in the center of the stator bobbin 24. Within the sleeve 25 there are mounted a ball bearing 26 and a lubricating bearing 27 under the ball bearing 26. The upper end of the ball bearing 26 abuts against an O-ring 28 and the lower end of the lubricating bearing 27 abuts against a C-type clamping ring 29. The lower end of the sleeve 25 is securely mounted on a circuit board 3 and a base 4.
This invention features an additional magnetic device [0017] 5 that is installed on the base 4 in a position corresponding to the lower end of the shaft 12. The magnetic device 5 comprises a permanent magnet 51 and a magnetic guide plate 52.
With reference to FIG. 4, when assembling, the [0018] iron casing 21 is mounted in the chamber 11. The ring-shaped permanent magnet 22 is mounted in the iron casing 21. The stator bobbin 24 with coil 23 thereon is then installed inside the ring-shaped permanent magnet 22. The ball bearing 26 and the lubricating bearing 27 are installed into the sleeve 25. Thereafter, the sleeve 25 is mounted inside the stator bobbin 24. The O-ring 28 and the C-type clamping ring 29 are used to secure the ball bearing 26 and the lubricating bearing 27, respectively, on the shaft 12. Finally, the magnetic device 5 comprising the permanent magnet 51 and magnetic guide plate 52 is installed on the base 4 in a position corresponding to the lower end of the shaft 12.
In contrast to the prior art, this invention presents the following advantages: [0019]
1. After assembling the [0020] heat dissipation fan 10, the magnetic device 5 will attract the shaft 12 so that the fan blade body 1 will remain in place during any type of operations, i.e., inverse operation, declined operations, or the like, without changing the total height of the fan.
2. Since the magnetic device [0021] 5 can attract the shaft 12 the magnetic device 5 thus generates a force on the ball bearing 26. This forces the rollers in the ball bearing 26 to move in the same level. The regular movement of the rollers in the ball bearing 26 therefore prolongs the life of the fan.
3. Since the magnetic device [0022] 5 can attract the shaft 12 a safe spacing may be kept between the C-type clamping ring 29 and the lubricating bearing 27. The friction between the C-type clamping ring 29 and the lubricating bearing 27 is thus eliminated.
Those skilled in the art will readily observe that numerous modification and alterations of the device may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims. [0023]

Claims

What is claimed is:

1. A heat dissipation fan comprising:

a fan blade body having a shaft mounted thereon;

an inner assembly installed within the fan blade body, wherein the shaft is inserted in the inner assembly, the inner assembly comprises an iron casing, a ring-shaped permanent magnet installed inside the iron casing, a stator bobbin with the winding of a coil thereof, and a sleeve installed in the center of the stator bobbin, and within the sleeve there are mounted a ball bearing and a lubricating bearing under the ball bearing, and wherein an upper end of the ball bearing abuts against an O-ring and a lower end of the lubricating bearing abuts against a C-type clamping ring, and wherein a lower end of the sleeve is securely mounted on a circuit board and a base; and

a magnetic device installed on the base in a position corresponding to a lower end of the shaft to attract the shaft.

2. The heat dissipation fan of claim 1 wherein the fan blade body comprises a chamber for accommodating the inner assembly.

3. The heat dissipation fan of claim 1 wherein the magnetic comprises a permanent magnet and a magnetic guide plate.