EP2068003B1

EP2068003B1 - A waterproof, dust-proof and salt fog-proof cooling fan

Info

Publication number: EP2068003B1
Application number: EP20080164436
Authority: EP
Inventors: Liu Ching Tang
Original assignee: PROTECHNIC ELECTRIC CO Ltd
Current assignee: PROTECHNIC ELECTRIC CO Ltd
Priority date: 2007-12-05
Filing date: 2008-09-16
Publication date: 2015-03-18
Anticipated expiration: 2028-09-16
Also published as: EP2068003A3; EP2068003A2

Description

FIELD OF THE INVENTION

The invention relates to a cooling fan, in particular to a waterproof, dust-proof and salt fog-proof cooling fan, as disclosed for example in DE-U-20302576 .

BACKGROUND OF THE INVENTION

Currently, the cooling fan is mainly composed of rotor, stator, rolling body and circuit board. Along with the use expansion of the cooling fan, the application environment of the fan is getting worse and worse from CPU, server, power supply to communication equipment and outdoor unit. Generally in the environment with moisture and salt fog, due to no protection for the stator and circuit board, rusted silicon steel sheet on the stator and damaged assembly on the circuit by short circuit easily cause fail of the fan in normal working.
There are two methods used currently: one is the vacuum coating technology, and the other is glue feed.
The vacuum coating technology is to coat a film on the stator and the circuit board for waterproof effect. Because the film closely affixes on the surface of the object, the inner stress of the film during coating easily damages the electrical components on the circuit board causing fail of the fan. In addition, because the film is very thin, the film easily ionizes in salt fog environment causing damaged electrical components by short circuit and the fail of the fan.
Glue feed technology is to firstly equip the stator and the circuit board on to the fan frame with mould, and then to place this part into the mould, after that to inject the glue in, finally to take it out from the mould after solidification of the glue. It mainly uses glue to fill the space surrounding the stator and the circuit board and the inner space for waterproof effect. By this method, the thick glue layer will encase the electrical components and causes poor heat dissipation, and that will cause burnout of the electrical components and fail of the fan. In addition, inner stress will be caused during solidification of the glue causing damaged electrical components and the fail of the fan.
DE-U-20302576 does not suggest the features of a sealing ring arranged in an U-shaped slot, and a further sealing ring with dust removal blades as defined in claim 1 of the present invention.

SUMMARY OF THE INVENTION

It is the object of the invention to provide a cooling fan with effective waterproof, dustproof and salt dog-proof performance.
This object is achieved by a waterproof, dust-proof and salt fog-proof cooling fan, according to claim 1. A fixed round table is arranged at center part of the fan frame, a fixed sleeve is arranged at center of the round table; an annular U-shaped slot is arranged at the end surface of the round table, and a sealing ring is arranged in the U-shaped slot. The cooling fan also comprises a waterproof cover body. Preferably, the waterproof cover body is fixedly connected on the fan frame through the sealing ring. It also comprises an axial fan hub with a reversed taper shaped fixed table stretching from the center of the inner cavity of the axial fan hub, and the fixed table connects with the main shaft. The foresaid round table is a blind hole with its opening at bottom side of the fan frame, the round table, sealing ring and the foresaid cover body form a sealed cavity, and the stator and circuit board assembly are arranged in the sealed cavity.
A sealing ring stretches downward from the top side of the inner cavity of the foresaid axial fan hub, couples of dust removal blades at equal interval stretch from the outer profile of the sealing ring. The foresaid sealing ring reversely sleeves on the fixed sleeve and forms a reverse U-shaped labyrinth channel cooperating with the foresaid fixed table.
Preferably, four slots are arranged with interval in between at the end surface of the foresaid round table, four buckles cooperating with the slots stretch from the side wall of profile of the foresaid waterproof cover body, and the buckles cooperating with the slots fix the waterproof cover body on the foresaid round table. A column stretches from the center of the foresaid waterproof cover body from the same direction of buckle, and the column directly sleeves on the fixed sleeve at the center of the round table.
Preferably, there is a transverse guide pipe on the side wall of the outer profile of the foresaid waterproof cover body, a sleeve is sleeved on the outer surface of the guide pipe, and the lead wire of the foresaid circuit board is led out from the foresaid guide pipe and the sleeve. There is a waterproof head cover arranged on the other end of the sleeve to cover the gap between the guide pipe and lead wire for ensuring a secure sealing performance of the sealed cavity.
Preferably, there is a shaft arranged in the fixed sleeve at the center of the foresaid round table, and the shaft connects with the main shaft at the center of the fanblade and/or the axial fan hub.
The invention has the following advantages that the application of the sealed cavity for sealing the stator and circuit board assembly breaks away from the traditional vacuum coating and glue feed technology featuring effective protection for the stator and circuit board assembly and achieving the goal of waterproof, dust-proof and salt fog-proof performance. The application of slot and buckle benefits a secure fastening effect and simple installation. The application of structure that lead wires are led out from the guide pipe and sleeve causes a convenient air-leakage test for the sealed cavity to ensure the quality of the fan. Moreover, a waterproof head cover is arranged at the end of the sleeve improving the air-tightness of the sealed cavity. In addition, it is with an excellent manoeuvrability and free of poor air-tightness of the cavity caused by the wires led out. At the part of rolling body shaft, because one end of the sleeve in which the shaft is placed is covered by the waterproof cover and the other end forms a non-contact sealed structure with dust removal blades in the axial fan hub and the U-shaped labyrinth channel, no matter the fan runs or stops, effective waterproof and dustproof effect can be achieved. Meanwhile, the non-contact design will not cause extra power consumption and is free of friction and heating, and thus the quality of the fan is ensured and a longer lifespan of the fan is achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will be apparent from and elucidated with reference to an embodiment described hereinafter.

In the drawings:

Fig. 1: is an exploded view according to an embodiment of the invention;
Fig. 2: is a cutaway view according to an embodiment of the invention; and
Fig. 3: is an outside view according to an embodiment of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

As shown in Fig. 1, Fig. 2 and Fig. 3, a waterproof, dust-proof and salt fog-proof fan, comprises a fan frame 6. A fixed round table 66 is arranged at center part of the fan frame 6, and a fixed sleeve 65 is arranged at center of the round table 66. There is a rolling body shaft 44 equipped in the fixed sleeve 65. A blind hole 62 is equipped between the round table 66 and the sleeve 65, and the stator and circuit board assembly 5 are arranged inside the blind hole 62. There are four slots 63 arranged at the end surface of the round table 66, an annular U-shaped slot 64 is arranged at the end surface of the round table 66, and a sealing ring 4 is arranged in the U-shaped slot 64. The invention also comprises a waterproof cover body 1, four buckles 11 cooperating with the slots stretch from the side wall of profile of the foresaid waterproof cover body 1, and the buckles 11 cooperating with the slots 63 fix the waterproof cover body 1 on the foresaid round table 66. A column 13 stretches from the center of the foresaid waterproof cover body 1 from the same direction of buckle 11, and the column 13 sleeves on the fixed sleeve 65 at the center of the round table 66 at the same time cooperating with the buckle 11 and slot 63. There is also a transverse guide pipe 12 on the side wall of the profile of the foresaid waterproof cover body 1, a sleeve 2 is sleeved on the outer surface of the guide pipe 12, and the lead wire 52 of the foresaid circuit board assembly 5 is led out from the foresaid guide pipe 12 and the sleeve 2. There is a waterproof head cover 3 arranged on the other end of the sleeve 2 to cover the gap between the guide pipe 2 and lead wire 52. It also comprises an axial fan hub 8 with a reversed taper shaped fixed table 82 stretching from the center of the inner cavity of the axial fan hub 8, and the fixed table 82 connects with the main shaft 81, the main shaft 81 connects with the shaft for cooperation. There is an annular permanent magnet arranged in the axial fan hub serving mainly to provide a permanent magnetic field.
For installation, it is only to equip the stator and circuit board assembly 5, permanent magnet 7, fan blade 8, shaft 61 at the corresponding position, then to install the sealing ring 4 in the U-shaped slot 64, and after that to pass the lead wire 52 through the guide pipe 12 on the side wall of the waterproof cover body 1, then to sleeve the sleeve 2 on to the guide pipe 12; finally, to sleeve the waterproof head cover 3 on. On the installation interface of the waterproof cover body 1 and sealing ring 4 and at the space between the column 1 and sleeve 65, corresponding waterproof sealant can be applied for better air-tightness. Certainly, it is OK to apply the corresponding sealant at junction edge of the waterproof cover body 1 and round table 66 after installation for a secure waterproof effect.
During use, as shown in Fig. 2, the foresaid sealing ring 83 reversely sleeves on the fixed sleeve 65 and forms a reverse U-shaped labyrinth channel cooperating with the foresaid fixed table 82. The design of labyrinth channel benefits an effective prevention or isolation of outside medium from coming into the fixed sleeve 65 to protect the shaft 61 achieving a normal work no matter the cooling fan runs or stops. Couples of dust removal blades 84 stretch from the outer profile of the sealing ring 83 in the axial fan hub 8. When the fan runs, the effect of centrifugal force blocks off the outside medium serving as an extra protection for the shaft 61 in the fixed sleeve 65 to achieve the normal work.
Of course, the changes like integrated waterproof cover body with the fan frame as a separate component, the round table as an independent component, equipping the stator and circuit board assembly on to the fan frame and then fixing the round table to the frame for sealing are within the protection range of the invention.
The embodiments are only used for explanation rather than limiting the invention, the above mentioned embodiments are the better embodiments, thus the equivalent change or decoration made according to the structure, the characteristic and the principle in the range of the patent application of the invention are included in the range of the patent application of the invention, which is defined by the appended claims.

Claims

A waterproof, dust-proof and salt fog-proof cooling fan, comprising:
- a fan frame (6), wherein

- a fixed round table (66) is arranged at center part of the fan frame (6),

- a fixed sleeve (65) is arranged at center of the fixed round table (66),

- an annular U-shaped slot (64) is arranged at the end surface of the fixed round table (66),

- a sealing ring (4) is arranged in the U-shaped slot (64),

- a waterproof cover body (1), wherein the waterproof cover body (1) is connected on the fan frame (6) through the sealing ring (4),

- an axial fan hub (8) with a reversed taper shaped fixed table (82) stretching from the center of the inner cavity of the axial fan hub (8), and

- the taper shaped fixed table (82) is connected with a main shaft (81), wherein the foresaid fixed round table (66) is a blind hole (62) with its opening directed away from the axial fan hub,

- the fixed round table (66), sealing ring (4) and the foresaid cover body (1) form a sealed cavity, and

- a stator of the cooling fan and circuit board assembly (5) are arranged in the sealed cavity, and

- a further sealing ring (83) stretches downward from the inner surface of the inner cavity of the foresaid axial fan hub (8),

- couples of dust removal blades (84) at equal interval stretch from the outer profile of the further sealing ring (83),

- and the foresaid further sealing ring (83) reversely sleeves on the fixed sleeve (65) and forms a reverse U-shaped labyrinth channel cooperating with the foresaid fixed table (82).
The waterproof, dust-proof and salt fog-proof cooling fan as set forth in claim 1, wherein
- four slots (63) are arranged with interval in between at the end surface of the foresaid round table (66),

- four buckles (11) cooperating with the slots (63) stretch from the side wall of profile of the foresaid waterproof cover body (1), and

- the buckles (11) cooperating with the slots (63) fix the waterproof cover body (1) on the foresaid round table (66).
The waterproof, dust-proof and salt fog-proof cooling fan as set forth in claim 1, wherein
- a transverse guide pipe (12) is arranged on the side wall of the profile of the foresaid waterproof cover body (1),

- a sleeve (2) is sleeved on the outer surface of the guide pipe (12), and

- the lead wire (52) of the foresaid circuit board (5) is led out from the foresaid guide pipe (12) and the sleeve (2), and

- a waterproof head cover (3) is arranged on the other end of the sleeve (2) to cover the gap between the sleeve (2) and lead wire (52) for ensuring a secure sealing performance of the sealed cavity.
The waterproof, dust-proof and salt fog-proof cooling fan as set forth in claim 1, wherein
- a column (13) stretches from the center of the foresaid waterproof cover body (1) from the same direction of buckle (11), and

- the column (13) directly sleeves on the fixed sleeve (65) at the center of the round table (66).
The waterproof, dust-proof and salt fog-proof cooling fan as set forth in claim 1, wherein
- a shaft (61) is arranged in the fixed sleeve (65) at the center of the foresaid round table (66), wherein

- the shaft (61) connects with the main shaft (81) at the center of the axial fan hub (8).