EP1629205A1

EP1629205A1 - Fan

Info

Publication number: EP1629205A1
Application number: EP04721030A
Authority: EP
Inventors: Young-Bok Son; Kyoung-Suk Lim; Jeong-Hun Kim; Sung-Man Hwang; Kwang-Won Lee
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2003-06-04
Filing date: 2004-03-16
Publication date: 2006-03-01
Also published as: KR20040105280A; KR100546650B1; WO2004109119A1; JP2006526733A

Abstract

The present invention provides a blowing fan (110), by which both high wind amount and high wind pressure can be simultaneously generated with a small size in an axial blowing direction. The present invention includes a rotational shaft (11) connected to a drive motor to rotate a cylindrical hub (12) fixed to the rotational shaft (11), at least one blade (13) spirally formed on an outer circumference of the hub (12) to have a width equal to or smaller than a radius of the hub (12), and a fan housing (15) having a predetermined curvature radius to enclose the at least one blade (13). And, the present invention includes a rotational shaft (11) connected to a drive motor to rotate, a cylindrical hub (12) fixed to the rotational shaft (11), and at least one blade (13) spirally formed on an outer circumference of the hub to have a width equal to or smaller than a radius of the hub (12).

Description

Fan

TECHNICAL FIELD . _, .

The present invention relates to a blowing fan used for home appliances such as air conditioner and the like or other manufacturing facilities.

BACKGROUND ART

Generally, various kinds of blowing fans forcibly blowing air are installed in home appliances such as air conditioners or ventilation systems of manufacturing facilities. And, the blowing fans are classified into axial blowing fans and centrifugal blowing fans according to air flow properties.

The axial blowing fan generates an air flow parallel with a rotational shaft to enable to blow a massive amount of air, but an air pressure generated from the axial blowing fan is low. The centrifugal blowing fan generates an inlet flow in a direction of an axial shaft to suck air inside and an outlet flow in a radial direction vertical to the rotational shaft to discharge the air. The object of the centrifugal blowing fan is to increase pressure by a centrifugal force. Hence, the centrifugal blowing fan blows a relatively small amount of air but generates a relatively high air pressure. In the system including the blowing fan, characteristics or features of the blowing fans are considered to adopt a blowing fan appropriate for the system. For instance, an indoor unit of an air conditioner requiring a high wind pressure adopts such a centrifugal blowing fan as a sirocco fan, a turbo fan, etc.

And, a ventilation system having an object of discharging air massively in a short time mainly utilizes an axial blowing fan. Thus, having their own characteristics or features respectively, the above- explained blowing fans are unable to increase both wind amount and wind pressure simultaneously. In case that a blowing fan simultaneously meeting both high wind pressure and high wind amount is required, a size of the blowing fan should be increased.

Unfortunately, the increased size of the blowing fan adopted by home appliances increases an overall product size as well as puts limitation on an installation location of the blowing fan in the system.

DISCLOSURE OF THE INVENTION

Accordingly, the present invention is directed to a blowing fan that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.

An object of the present invention is to provide a blowing fan, by which both high wind amount and high wind pressure can be simultaneously generated with a small size in an axial blowing direction.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a blowing fan according to the present invention includes a rotational shaft connected to a drive motor to rotate, a cylindrical hub fixed to the rotational shaft, at least one blade spirally formed on an outer circumference of the hub to have a width equal to or smaller than a radius of the hub, and a fan housing having a predetermined curvature radius to enclose the at least one blade. -

The curvature radius of the fan housing gradually increases toward upper and lower parts of the fan housing from a middle part of the fan housing. Hence, the upper and lower parts of the fan housing extend to expand upward and downward from the middle part, respectively.

And, the curvature radius of the upper part of the fan housing is different from that of the lower part of the fan housing. Preferably, the lower part of the fan housing has the curvature radius greater than that of the upper part thereof.

Moreover, the middle part of the fan housing has an identical curvature radius. Preferably, a ratio (OIL) of a diameter (D) of the middle part of the fan housing over a length (L) of the middle part is 5.

The fan housing further includes first and second fan housings symmetrically confronting each other centering around the rotational shaft.

To further achieve these and other advantages and in accordance with the purpose of the present invention, a blowing fan includes a rotational shaft connected to a drive motor to rotate, a cylindrical hub fixed to the rotational shaft, and at least one blade spirally formed on an outer circumference of the hub to have a width equal to or smaller than a radius of the hub .

The at least one blade has a predetermined curvature radius to extend from an outer circumference of the hub. And, the curvature radius of a lower end of the at least one blade is different from that of an upper end of the at least one blade. Preferably, the curvature radius of the lower end of the at least one blade is greater than that of the upper end of the at least one blade. The at least one blade may extend straight on the outer circumference of the hub, and top and bottom of the hub may be closed.

Moreover, an angle formed by a side end of the at least one blade increases from a lower part of the hub toward an upper part of the hub. Hence, an outlet angle (θ_e) " of the at least one blade is greater than an inlet angle (θ() thereof. Preferably, an inlet angle (θ{) of the at least one blade is 35°.

.. Meanwhile, the at least one blade may extend to taper in thickness from the outer circumference of the hub.

And, a ratio (D_h/D_b) of a diameter (D_h) of the hub over a diameter (D_b) of a circle formed by a rotational locus of the at least one blade is 0.4 ~ 0.8. More preferably, the ratio (D /D_b) of the diameter (D_h) of the hub over the diameter (D_b) of the circle formed by the rotational locus of the at least one blade is 0.6.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings:

Fig. 1 is a perspective view of a blowing fan according to the present invention; Fig. 2 is a front view of a blowing fan shown in Fig. 1; Fig. 3 is a layout of a blowing fan shown in Fig. 1 ; Fig. 4 is a perspective view of a blowing fan having a fan housing according to the present invention;

Fig. 5 is a cross-sectional view of a fan housing according to the present invention; and Fig. 6 is a graph of wind amount and noise of a blowing fan depending on a ratio of diameter over length of a middle part of a fan housing according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

Fig. 1 is a perspective view of a blowing fan according to the present invention. Referring to Fig. 1, a blowing fan according to the present invention includes a rotational shaft 11 connected to a drive motor (not shown in the drawing) to rotate, a cylindrical hub 12 fixed to the rotational shaft 11, and a pair of blades 13 spirally formed on an outer circumference of the hub 12.

Top and bottom sides of the hub 12 are closed, and each of the blades 13 has a width W equal to or smaller than a radius D_h/2 of the hub 12.

And, each of the blades 13 has a predetermined curvature radius and extends from a circumference surface of the hub 12, thereby having a hemi-circular curved shape.

Preferably, a curvature radius of an upper end 13b of each of the blades 13 is formed different from that of a lower end 13a of each of the blades 13 for a smooth air flow. Specifically, the curvature radius of the lower end 13a is preferably formed greater than that of the upper end 13b. In this case, incoming air goes past by the lower end 13a of the blade and outgoing air goes past by the upper end 13b of the blade. For the convenience of explanation, it is assumed in the following that air is sucked into a lower part of the blowing fan and then blown out via an upper part of the blowing fan. Thus, air is smoothly sucked via the lower end 13a of the blade having the greater curvature radius and then gathers at the upper end 13b of the blade to be blown out. Hence, both wind pressure and amount of the blowing fan increase.

Of course, each of the blades 13 may extend straight from the circumference of the hub 12 or be variously shaped. In such a case, the width W of the blade is equal to or smaller than the radius D_h/2 of the hub 12 as well.

Fig. 2 is a front view of a blowing fan shown in Fig. 1.

Referring to Fig. 2, an angle of a side end 13e is formed to increase toward an upper part of the hub 12 from a lower part of the hub 12. Moreover, in each of the blades 13, an outlet angle θ_β is formed greater than an inlet angle 0,. In this case, one angle formed between tangent and horizontal lines of the side end 13e of the blade in the air-incoming part is called the inlet angle θ[, and the other angle formed between tangent and horizontal lines of the side end 13e of the blade in the air-outgoing part is called the outlet angle θ_e.

The inlet angle θ_\ means an incoming angle of air flowing into the lower end 13a of the blade, whereas the outlet angle θ_e means an outgoing angle of air discharged via the upper end 13b of the blade.

And, the inlet angle 0; is preferably formed 35°. Specifically, as a test result of measuring noise of the blowing fan according to a variation of the inlet angle θ\, the noise generated from the blowing fan is changed according to the variation of the inlet angle θ as well. Namely, the noise of the blowing fan indicates about 31dB if the inlet angle θ_\ is 35°, or about 36dB in other cases. This is because a streamline of the incoming air at 35° of the inlet angle θ_\ of the blade 13 almost comcides₎ with the inlet angle θ to minimize the occurrence of turbulence. Fig. 3 is a layout of a blowing fan shown in Fig. 1.

Referring to Fig. 3, a thickness t_b of each of the blades 13 preferably decreases externally as each of the blades 13 extends from the circumference of the hub 12. Such a shape of the blade 13 makes the center of gravity move inward to reduce a moment generated from the revolution of the blowing fan and the vibration of the bowing fan accordingly.

A hub ratio (D_h D_b) of the blowing fan according to the present invention is preferably formed 0.4 ~ 0.8 to provide high wind amount and pressure. More preferably, the hub ratio (D_h/Db) is formed 0.6.

In this case, the hub ratio (D_h/D_b) is defined as a ratio of a diameter D_h of the hub 12 versus a diameter D_b of a circle formed by a rotational locus of the blade 13.

In viewpoint of fluid mechanics, it is known that a size of a blade greatly affects performance of a blowing fan. Yet, as a test result of preparing blowing fans having various hub ratios (D_h/Db), the wind amount and pressure are substantially good if the hub ratio (D_h/D_b) is 0.4 ~ 0.8. Specifically, optimal performance appears at 0.6 of the hub ratio (D_h/D_b).

Fig. 4 is a perspective view of a blowing fan having a fan housing according to the present invention.

Referring to Fig. 4, a blowing fan according to the present invention includes a cylindrical housing 15 having a predetermined curvature radius to enclose the blades 13. The fan housing 15 has open top and bottom to guide a flow of air, which flows into the lower part of the blowing fan and is then blown out to the upper part of the blowing fan, and enables the air to flow in and to be discharged smoothly without attenuating a rotational force of the blowing fan. Besides, the fan housing 15 is operative in raising a static pressure of a flowing air. The fan housing 15 has a curvature radius increasing toward both its upper and lower parts from its middle part. Namely, the upper and lower parts of the fan housing 15 extend upward and downward from the middle part to gradually expand in an outer radial direction, thereby forming a kind of funnel shape.

Hence, the fan housing 15 provides a shape having both expanding upper and lower parts to enable the blowing fan to suck/discharge air more smoothly.

Preferably, a curvature radius of the upper part of the fan housing 15 is formed different from that of the lower part of the fan housing 15. More preferably, the lower part of the fan housing 15 is formed to have the curvature radius greater than that of the upper part of the fan housing 15. Hence, the lower part of the fan housing 15 having the greater curvature radius enables smooth air intake, and the air gathers in the upper part of the fan housing 15 having the smaller curvature radius to be blown out.

Moreover, the middle part of the fan housing 15 is formed to have an identical curvature radius. Hence, the fan housing 15 forms an orifice shape having a concave middle part to provide a pressure difference between both ends of the middle part, whereby the pressure difference enables the blowing fan to blow more air.

Meanwhile, the fan housing 15 may include first and second fan housings 15a and 15b symmetrically confronting each other centering around the rotational shaft 11.

In order for the blowing fan to suck/discharge the air more smoothly, a curvature radius of each of the first and second fan housings 15a and 15b is formed to gradually increase toward its upper and lower parts from its middle part. Moreover, the curvature radius of the upper part of each of the first and second fan housings 15a and 15b is formed different from that of the lower part of each of the first and second fan housings 15a and 15b. Preferably, the curvature radius of the lower part of each of the ' first and second fan housings 15a and 15b is formed greater than that of the upper part of each of the first and second fan housings 15a and 15b.

._ Besides, when the first and second fan housings 15a and 15b are installed in an indoor unit of an air conditioner or the like, each corner of the first and second fan housings 15a and 15b is installed to be contacted with an inner wall of an indoor unit. Fig. 5 is a cross-sectional view of a fan housing according to the present invention.

Referring to Fig. 5, it is known that a ratio (D/L) of a diameter D of a middle part of the fan housing 15 over a length L of the middle part affects the wind amount and noise characteristics of the blowing fan. Namely, the test confirms that the wind amount and noise of the blowing fan varies according to the variation of the ratio (D/L) of the diameter D over the length L.

Fig. 6 is a graph of wind amount and noise of a blowing fan depending on a ratio of diameter over length of a middle part of a fan housing according to the present invention. A test is performed to measure a wind amount and noise of a blowing fan in case that a ratio (D/L) of a diameter D of a middle part of a fan housing 15 over a length L thereof is 2.5 or 5. In both cases, the noise, as shown in Fig. 6, increases if the wind amount increases.

Yet, compared to the noise in the case that the ratio (D/L) is 2.5, the noise is less generated at the identical wind amount in the other case that the ratio (D/L) is 5. Hence, in the blowing fan according to the present invention, the ratio (D/L) of the diameter D of the middle part of the fan housing 15 over the length L thereof is preferably formed to have 5.

Therefore, the blowing fan according to the present invention is constructed to fit an indoor unit of an air conditioner and can be further applied to all kinds of systems that need the blowing force of air identically or similarly.

INDUSTRIAL APPLICABILITY

Accordingly, the present invention has the following advantage. The blowing fan according to the present invention improves the structures of the blade and fan housing, thereby enabling to simultaneously generate both high wind amount and high wind pressure with a small size thereof.

While the present invention has been described and illustrated herein with reference to the preferred embodiments thereof, it will be apparent to those skilled in the art that various modifications and variations can be made therein without departing from the spirit and scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of this invention that come within the scope of the appended claims and their equivalents.

Claims

WHAT IS CLAIMED IS:

1. A blowing fan comprising: , a rotational shaft connected to a drive motor to rotate;

! a cylindrical hub fixed to the rotational shaft; at least one blade spirally formed on an outer circumference of the hub to have a width equal to or smaller than a radius of the hub; and a fan housing having a predetermined curvature radius to enclose the at least one blade.

2. The blowing fan of claim 1, wherein the curvature radius of the fan housing gradually increases toward upper and lower parts of the fan housing from a middle part of the fan housing.

3. The blowing fan of claim 2, wherein the upper and lower parts of the fan housing extend to expand upward and downward from the middle part, respectively.

4. The blowing fan of claim 3, wherein the curvature radius of the upper part of the fan housing is different from that of the lower part of the fan housing.

5. The blowing fan of claim 4, wherein the lower part of the fan housing has the curvature radius greater than that of the upper part thereof.

6. The blowing fan of claim 2, wherein the middle part of the fan housing has an identical curvature radius.

7. The blowing fan of one of claim 2 and claim 6, wherein a ratio (D/L) of a diameter (D) of the middle part of the fan housing. over a length (L) of the middle part is 5. ^"

8. The blowing fan of one claim 1 or claim 6, wherein the fan housing comprises first and second fan housings symmetrically confronting each other centering around the rotational shaft.

9. A blowing fan comprising: a rotational shaft ^"connected to a driv motor to rotate; a cylindrical hub fixed to the rotational shaft; and at least one blade spirally formed on an outer circumference of the hub to have a width equal to or smaller than a radius of the hub.

10. The blowing fan of claim 1 or claim 9, wherein the at least one blade has a predetermined curvature radius to extend from an outer circumference of the hub.

11. The blowing fan of claim 10, wherein the curvature radius of a lower end of the at least one blade is different from that of an upper end of the at least one blade.

12. The blowing fan of claim 11, wherein the curvature radius of the lower end of the at least one blade is greater than that of the upper end of the at least one blade.

13. The blowing fan of claim 1 or claim 9, wherein the at least one blade extends straight on the outer circumference of the hub.

14. The blowing fan of claim 1 or claim 9, wherein top and bottom of the ' hub are closed.

.- 15. The blowing fan of claim 1 or claim 9, wherein an angle formed by a side end of the at least one blade increases from a lower part of the hub toward an upper part of the hub.

16. The blowing fan of claim 1 or claim 9, wherein an outlet angle (0_e) -of the at least one blade is greater than an inlet angle (θ_\) thereof.

17. The blowing fan of claim 1 or claim 9, wherein an inlet angle (θ ) of the at least one blade is 35 ° .

18. The blowing fan of claim 1 or claim 9, wherein the at least one blade extends to taper in thickness from the outer circumference of the hub.

19. The blowing fan of claim 1 or claim 9, wherein a ratio (D_h/D_b) of a diameter (D_h) of the hub over a diameter (D_b) of a circle formed by a rotational locus of the at least one blade is 0.4 - 0.8.

20. The blowing fan of claim 19, wherein the ratio (D_h/D_b) of the diameter (D_h) of the hub over the diameter (D_b) of the circle formed by the rotational locus of the at least one blade is 0.6.