Axial flow fan

Abstract

The present invention relates to an axial flow fan and, more particularly, to an axial flow fan comprising: a hub; and a plurality of blades that are disposed radially on the circumference of the hub such that roots of the blades are coupled to the hub, wherein the blades are formed so as to have a waveform shape such that a position of a trailing edge gradually approaches and recedes from a leading edge repeatedly, the trailing edge is positioned on the same plane, and an installation angle changes in the lengthwise direction of the blades.

Claims

1. An axial flow fan including a hub, and a plurality of blades disposed radially on a circumference of the hub, each of the plurality of blades having one end coupled to the hub, wherein a radial direction of the axial flow fan is defined as a longitudinal direction, a length obtained by connecting a leading edge and a trailing edge of each blade is defined as a chord length, and an angle of the trailing edge of each blade with respect to a horizontal plane of the axial flow fan is defined as a setting angle α, the trailing edge of each blade repeatedly retracts and advances in a gradual manner with respect to the leading edge in the longitudinal direction, such that the setting angle of the trailing edge is continuously changed in the longitudinal direction, and wherein the leading edge and the trailing edge repeatedly retract and advance in the longitudinal direction a number of times respectively, such that the number of times the trailing edge repeatedly retracts and advances is greater than the number of times the leading edge repeatedly retracts and advances, and each portion of the trailing edge along the longitudinal direction is positioned on a same horizontal plane perpendicular to a rotary shaft of the axial flow fan.

2. The axial flow fan of claim 1, wherein the chord length of each blade is continuously changed in the longitudinal direction.

3. The axial flow fan of claim 1, wherein the each blade is formed so that the trailing edge retracts and advances in a range between 6 mm and 8 mm from the leading edge.

4. The axial flow fan of claim 1, further comprising a fan band formed as a ring and connecting respective other ends of the plurality of blades to each other.

Description

DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a view showing an arrangement of a general heat exchanger and an axial flow fan.

(2) FIG. 2 is a view showing a general air flow fan.

(3) FIG. 3 is a view showing an axial flow fan according to the present invention.

(4) FIG. 4A is a view comparing the axial flow fan according to the present invention and a conventional axial flow fan as to the chord length.

(5) FIG. 4B is a view comparing the axial flow fan according to the present invention and a conventional axial flow fan as to the setting angle.

(6) FIG. 5 is a view showing an analysis result of the axial flow fan according to the present invention.

(7) FIG. 6 is a view defining a chord length and a setting angle of the axial flow fan according to the present invention.

(8) FIG. 7 is another view showing the axial flow fan according to the present invention.

(9) FIG. 8A is a view showing a fan band of the axial flow fan according to conventional invention.

(10) FIG. 8B is a view showing a fan band of the axial flow fan according to the present invention.

(11) FIG. 9 is a view showing an effect of the axial flow fan according to the present invention.

BEST MODEL

(12) Hereinafter, an axial flow fan according to the present invention having the characteristics as described above will be described in detail with reference to the accompanying drawings.

(13) FIG. 3 is a view showing an axial flow fan according to the present invention and FIG. 4 is a view comparing the axial flow fan according to the present invention and a conventional axial flow fan.

(14) As shown in FIGS. 3, 4A and 4B, an axial flow fan 100 according to the present invention may be formed to include a hub 120 and blades 110, and may reduce noise and satisfy characteristics of an air volume without changing other configuration forms such as a shroud and the like by specifying forms including a chord length L and a setting angle α of the blades 110.

(15) The hub 120 is a portion forming a central region of the axial flow fan 100, and a rotary shaft is connected to a center of the axial flow fan 100.

(16) In addition, the hub 120 is seated with a fan motor for driving the axial flow fan 100.

(17) A plurality of blades 110 are disposed radially on a circumference of the hub 120 and axially transfer air.

(18) Meanwhile, the axial flow fan 100 according to the present invention may further include a fan band 130 formed in a disc form to connect the respective blade ends of the blades 110 to each other.

(19) When the fan band 130 is further formed, overall structural safety of the axial flow fan 100 may be further increased.

(20) Further, in the axial flow fan according to the present invention, a radial direction of the axial flow fan 100 is defined as a longitudinal direction.

(21) The blade 110 includes a leading edge 111, which is a region that is first in contact with air according to a rotation direction, and a trailing edge 112, which is a region in which the air escapes to a side opposite to the leading edge 111.

(22) The chord length L described above means a length obtained by connecting the leading edge 111 and the trailing edge 112 of the blade 110 by a straight line, and the setting angle α means an angle formed with a horizontal plane of the axial flow fan 100 at the trailing edge 112 (see FIG. 7).

(23) The blade 110 of the axial flow fan 100 according to the present invention has a waveform form in which a position of the trailing edge 112 gradually repeats retraction and advancement from the leading edge 111 toward the longitudinal direction thereof.

(24) Since the blade 110 has the waveform form in which the position of the trailing edge 112 thereof gradually repeats the retraction and advancement in the longitudinal direction, the position of the trailing edge 112 is continuously changed toward the longitudinal direction and the setting angle α is also continuously changed toward the longitudinal direction.

(25) In this case, the chord length L of the blade 110 of the axial flow fan according to the present invention may be continuously changed toward the longitudinal direction, and to this end, the leading edge 111 and the trailing edge 112 may have the shapes in which the positions thereof are continuously changed toward the longitudinal direction.

(26) As shown in FIG. 4A, in the case of the conventional axial flow fan, the chord length thereof is constantly formed in the longitudinal direction from the hub, while since the position of the trailing edge 112 of the blade 110 is formed in the waveform form, the axial flow fan 100 according to the present invention is formed in such a shape that the chord length L repeats lengthening and shortening according to the retraction and the advancement of the trailing edge 112.

(27) Further, as shown on FIG. 4B, in the case of the conventional axial flow fan, a setting angle thereof is also gently formed corresponding to the chord length which is gently changed toward the longitudinal direction.

(28) On the other hand, since the blade 110 of the axial flow fan 100 according to the present invention has the waveform form in which the chord length L from the leading edge 111 is different, the setting angle α is also formed to have the waveform form toward the longitudinal direction.

(29) That is, in the blade 110 of the axial flow fan 100 according to the present invention, since the setting angle α of the trailing edge 112 that the air escapes from the blade 110 is formed to be different in the longitudinal direction, a flow of air is also distributed at different angles by the trailing edge 112 having different angles.

(30) In other words, as the axial flow fan 100 has a flow distribution having different angles in the longitudinal direction of the outlet of air passing through the trailing edge 112, the axial flow fan 100 has an effect in which a pressure distribution is dispersed and noise is reduced.

(31) In addition, as the flow of air is each distributed in a direction from the leading edge 111 to the trailing edge 112, a guide path in which the air flows is formed such that the air moves from the leading edge 111 to the trailing edge 112 along a guided flow path and escapes the blade 110.

(32) Since this may minimizes the flow of air in the longitudinal direction in the hub 120, there is an effect in which power consumption is reduced.

(33) In this case, it is preferable that the blade 110 reduces the noise by forming a plurality of flow paths of air, and is formed so that the waveform form of the trailing edge 112 is repeated at least twice or more toward the longitudinal direction in order to minimize the air flowing in the longitudinal direction in the hub 120, and it is possible to variously set the number of repetitions according to the longitudinal direction.

(34) FIG. 5 is a view showing an analysis result of the axial flow fan according to the present invention.

(35) As shown in FIG. 5, power consumption according to a length of the trailing edge 112 that retracts and advances from the leading edge 111 at the same air volume was analyzed based on two cases according to an operation of the axial flow fan 100 according to the present invention at the same air volume.

(36) The axial flow fan 100 including the blade 110 including the trailing edge 112 having the waveform shape according to the present invention shows that the power consumption is reduced as the length of the trailing edge 112 that retracts and advances from the leading edge 111 is increased, and when the trailing edge 112 is retracted and advanced to a length of 7 mm from the leading edge 111, a result in which the power consumption is maximally reduced was produced.

(37) However, when the length is increased from 8 mm to 9 mm, a result in which the power consumption of one case is increased was produced, and based on such a result, it is preferable that the blade 110 of the axial flow fan 100 according to the present invention is formed so that the trailing edge 112 is retracted and advanced in the range between 6 mm and 8 mm from the leading edge 111.

(38) However, since the axial flow fan 100 may be variously formed depending on the size of the axial flow fan 100 and the place at which the axial flow fan 100 is installed, the axial flow fan 100 is not limited thereto.

(39) FIG. 7 is another view showing the axial flow fan according to the present invention and FIG. 8B is a view showing a fan band of the axial flow fan according to the present invention.

(40) As shown in FIG. 7, it is preferable that the blade 110 of the axial flow fan 100 according to the present invention is formed so that the trailing edge 112 of the blade 110 is positioned on the same plane in the longitudinal direction in the hub 120.

(41) As shown in FIGS. 7, 8A and 8B, since the trailing edge 112 of the blade 110 is formed on the same plane at the time of advancing (raking) in the longitudinal direction, a height of the fan band 130 due to a repeated fluctuation of the height can be minimized.

(42) As an example, as shown on FIG. 8B, by forming the trailing edge 112 so as to be positioned on the same plane in the longitudinal direction, the height of the fan band 130 may be reduced by 35% as compared with the conventional axial flow fan, and as a result, a result in which a weight of the axial flow fan 100 is reduced by 13.5% was produced.

(43) As shown in FIG. 9, since the trailing edge 112 of the blade 110 of the axial flow fan 100 according to the present invention has the waveform shape that retracts and advances from the leading edge 111 and is formed to be repeated at least twice or more in the longitudinal direction, the flow path of air is differently distributed depending on the position of the trailing edge 112 and as a result, the noise may be reduced according to a dispersion of a pressure distribution, and since the guide path in which the air flows is formed according to the waveform shape of the trailing edge 112, the air flowing in the longitudinal direction in the hub 120 may be minimized and the power consumption may be reduced.

(44) Accordingly, in the axial flow fan 100 according to the present invention, a result in which the air volume is increased and the noise is reduced is produced as compared with the conventional axial flow fan based on the same power consumption of 300 W and 400 W.

(45) In addition, as described above, since the height of the fan band 130 may be formed to be reduced as compared with the conventional axial flow fan, a result in which the weight of the axial flow fan 100 is also reduced was produced.

(46) The present invention is not limited to the above-mentioned embodiments, and may be variously applied, and may be variously modified without departing from the gist of the present invention claimed in the claims.

DESCRIPTION OF REFERENCE NUMERALS

(47) 100: axial flow fan 110: blade 111: leading edge 112: trailing edge 120: hub 130: fan band