Cooling fan with dynamic and static blades

Abstract

A cooling fan with dynamic and static blades includes a fan and a static blade device. The fan has a fan frame with two lateral sides forming an inlet and an outlet respectively and provides dynamic blades in the fan frame. The static blades are mounted at the outlet and extend into the outlet of fan frame to reduce distance between the dynamic blades and the static blades for saving space thereof.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to a cooling fan with dynamic and static blades and particularly to a fan in which the dynamic blades being arranged to separate from the static blades.

2. Brief Description of the Related Art

The conventional axial flow fan can be divided into single stage blade type and double stage blade type. The axial flow fan with single stage blades is a fan with dynamic blades and the axial flow fan with double stage blades is a fan with dynamic blades integrally arranged with static blades for offering fluid a propelling force by way of the dynamic and static blades rotating with the fan shaft.

The preceding fan with dynamic blades provides the outward direction of air flow has to be inclining with the axis of the fan based on the principle of fluid mechanics such that the outward fluid flows divergently instead of being concentrative. In this way, the direction of air flowing is inconsistent with the cooling fins and it results in increasing resistance and lowering air flow passing through the cooling fins such that unfavorable heat dissipation effect with loud noise is obtained.

The fan with dynamic blades integral with static blades improves the deficiency of the dynamic blade fan and a static blade stage is added in the fan at the rear side of the dynamic blades. The hollow frame of the fan is shared with the dynamic blades and the static blades and the static blades are able to rectify the diverging air flow from the dynamic blades to concentrate the air flow outward the fan. In this way, the direction of air flow is approximately parallel to the axial direction of the fan and consistent with the direction of the cooling fan for increasing air flow passing through the cooling fins and attenuating noise.

However, the fan with dynamic blades integral with static blades still faces many problems in practice. Due to the dynamic blades being arranged integrally with the static blades, the fan is suitable for being operated in a specific environment only in order to maintain favorable work condition, high efficiency, sufficient flow rate and low noise. Further, either the dynamic blades or the static blades is damaged, both the blades have to be replaced at the same time such that high maintenance and repair costs results in a great burden to the user.

Taiwanese Patent Official Gazette No. 488497 entitled FAN WITH SUPERCHARGING FLOW GUIDE DEVICE Referring and No. 523652 entitled COMPOSITE FAN WITH FAN FRAME disclose the static blades are disposed to separate from the dynamic blades for promoting air flow rate and air pressure and suitable for different environment needs.

The problem of the preceding prior art is in that a large distance is created between the dynamic blades and the static blades after assembling to each other and it reduces kinetic energy of the fluid. A clearance between the assembled parts leads the fluid to overflow before reaching the static blades and it is unfavorable for increasing air pressure.

SUMMARY OF THE INVENTION

A main object of the present invention is to a cooling fan with dynamic and static blades in which the static blades are independent from the dynamic blades and extend toward the dynamic blades to shorten distance between them and to save the space of the fan.

In order to achieve the preceding object, the cooling fan with dynamic and static blade includes a fan, having a fan frame with a hollow flow passage, the flow passage having an inlet at a lateral side of the fan and an outlet at another lateral side of the fan frame; a support seat, being disposed near the outlet and joined with a plurality of dynamic blades; and at least a static blade device, being mounted to the outlet, providing a hollow frame member with a plurality of static blades, the static blades extending axially toward one of the lateral sides and into the outlet for reducing a space between the dynamic blades and the static blades.

BRIEF DESCRIPTION OF THE DRAWINGS

The detail structure, the applied principle, the function and the effectiveness of the present invention can be more fully understood with reference to the following description and accompanying drawings, in which:

FIG. 1 is a disassembled perspective view of a preferred embodiment of a cooling fan with dynamic and static blades according to the present invention;

FIG. 2 is a disassembled perspective view similar to FIG. 1 illustrating the preceding embodiment being projected from another direction;

FIG. 3 is a perspective view of the preceding embodiment;

FIG. 4 is a sectional view of the preceding embodiment;

FIG. 5 is a sectional view similar to FIG. 4 illustrating another type of the hub thereof;

FIG. 6 is a disassembled perspective view of another preferred embodiment of a cooling fan with dynamic and static blades according to the present invention;

FIG. 7 is a perspective view of the preceding embodiment;

FIG. 8 is a disassembled perspective view similar to FIG. 6 illustrating the preceding embodiment being projected from another direction;

FIG. 9 is an assembled perspective view illustrating the preceding embodiment being projected from another direction;

FIG. 10 is a sectional view of the preceding embodiment; and

FIG. 10a is an enlarged diagram of the part of dash circle in FIG. 10.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 to 4, the first preferred embodiment of a cooling fan with dynamic and static blades according the present invention includes a fan 11 and at least a static blade device 12. The fan 11 has a fan frame 111 with a hollow passage 112 and the passage 112 provides an inlet 113 at a side of the fan frame 111 and an outlet 114 at another side of the frame 111. A bearing seat 115 is disposed near the outlet 114 with a dynamic blade 116 being movably attached to the bearing seat 115.

The static blade device 12 has a hollow frame member 121 with a plurality of static blades 122 being disposed inside. Each of the static blades 122 connects with the inner wall of the frame member 121 at an end thereof and extends to a common position, which is the center of the frame member 121 in the present embodiment, at the other end thereof respectively to connect with a hub 123 in a way of being perpendicular to the outer wall of the hub 123. Alternatively, the other ends of the static blades 122 extend to the common position and join at the common position (not shown). The static blades 122 extrude outward the frame member 121 axially.

Besides, the fan frame 111 has receiving parts 117 such as through holes and the frame member 121 provides joining parts 124 corresponding to the receiving parts 117. The joining parts 124 can be locks, threaded fasteners or any other engaging means such as adhesives attached to the receiving parts 117.

The static blade device 12 is arranged to face the outlet 114 of the fan 11 and mounted to the outlet 114 with the joining parts 124 engaging with the receiving parts 117. Meanwhile, the static blades extend into the outlet 114, that is, extend into the flow passage 112 such that space between the dynamic blades 116 and the static blades 122 is reduced and the fluid passes through the static blades 122 without decreasing kinetic energy of the fluid after passing through the dynamic blades 116. Further, comparing to the prior art, the fan of the present invention is more capable of allowing the fluid flowing along the axial direction of the fan in addition to increasing fluid pressure.

Furthermore, the static fan device 12 is available for the fan 11 being joined to a radiator or the like, that is, the frame member 121 of the static blade device 12 provides joining parts corresponding to the radiator or the like. The joining parts can be locking pieces, threaded fasteners or any other engaging devices as well (not shown). Besides, the static blades 122 can be either integrally made with the frame member 121 and/or the hub 132 or an independent piece.

In addition, the hub 123 of the static blade device 12 can be hollow except solid from standpoint of material reduction. The outer wall of the hub 123 can be provided a conical shape as shown in FIG. 5 for the fluid being guided to concentrate toward the shaft thereof.

Referring to FIGS. 6 to 10 and FIG. 10a, another embodiment of a cooling fan with dynamic and static blades according the present invention is illustrated. The entire structure and function almost the same as the first embodiment so that the identical parts are designated with the same numerals and no details will be described further. The difference of the present embodiment is in that the hollow fame member 121 opposite to a side of the fan frame 111 provides a protruding baffle part 125 corresponding to the flow passage 112 and the baffle part 125 is mounted to the fan 11 with the static blade device 12 such that the baffle part 125 extends into the flow passage 112 to prevent from the fluid flowing outward via the joining seam between the static blade device 12 and the fan 11.

It is appreciated that the cooling fan with dynamic and static blades according the present invention has overcome problems resided in the prior art. The static blades 122 project outward the frame member 121 and that means the frame member 121 can be thinner than that in the conventional fan. The static blades 122 extending into the inlet 113 of the fan 11 not only increases the fluid pressure but also allows the gross thickness of the fan 11 and the static blade device 12 being smaller than of the prior art. Further, the baffle part 125 is capable of preventing from fluid decrease caused by overflow and keeping flow rate of the fluid into the inlet 113.

While the invention has been described with referencing to preferred embodiments thereof, it is to be understood that modifications or variations may be easily made without departing from the spirit of this invention, which is defined by the appended claims.

Claims

1. A cooling fan with dynamic and static blades, comprising:

a fan, having a fan frame with a hollow flow passage, the flow passage having an inlet at a lateral side of the fan and an outlet at another lateral side of the fan frame;

a support seat, being disposed near the outlet and joined with a plurality of dynamic blades; and

at least a static blade device, being mounted to the outlet, providing a hollow frame member with a plurality of static blades, the static blades extending axially toward one of the lateral sides and into the outlet for reducing a space between the dynamic blades and the static blades.

2. The cooling fan with dynamic and static blades as defined in claim 1, wherein the fan frame has a plurality of receiving parts and the frame member provides a plurality of joining parts corresponding to the receiving parts.

3. The cooling fan with dynamic and static blades as defined in claim 1, wherein the joining parts are locking pieces, threaded fasteners or the like to engage with receiving parts.

4. The cooling fan with dynamic and static blades as defined in claim 1, wherein the static blade device is mounted to a radiator with the fan.

5. The cooling fan with dynamic and static blades as defined in claim 4, wherein the frame member provides a plurality of joining parts for being joined to the radiator.

6. The cooling fan with dynamic and static blades as defined in claim 5, wherein the joining parts are locking pieces, threaded fastener for being joined to the radiator.

7. The cooling fan with dynamic and static blades as defined in claim 1, wherein the static blades connect with the inner wall of the frame member at an end thereof respectively and extend toward the center of the frame member to connect with each other at another end thereof respectively.

8. The cooling fan with dynamic and static blades as defined in claim 1, wherein the static blades connect with the inner wall of the frame member at an end thereof respectively and extend toward the center of the frame member to connect with a hub at another end thereof respectively.

9. The cooling fan with dynamic and static blades as defined in claim 8, wherein the hub is solid or hollow.

10. The cooling fan with dynamic and static blades as defined in claim 8, wherein the hub has a conical shape slanting toward the center thereof or a cylindrical shape.

11. The cooling fan with dynamic and static blades as defined in claim 1, wherein the frame member provides a protruding baffle part corresponding to the flow passage at the internal circumference of a side thereof, which faces the fan frame.

12. The cooling fan with dynamic and static blades as defined in claim 7, wherein the static blades are integrally made with the frame member or independent from the frame member.

13. The cooling fan with dynamic and static blades as defined in claim 8, wherein the static blades are integrally made with the frame member or independent from the frame member.