NOISE REDUCTION-TYPE IMPELLER

Description

TECHNICAL FIELD

The present invention relates to a noise reduction-type impeller that reduces noise generated by a specific band or the flow resistance of air when air blowing amount is increased.

BACKGROUND ART

In general, an axial flow fan introduces gas in an axial direction and discharges the introduced gas in the axial direction, and there is a problem of increasing flow resistance or increasing noise in a specific band by rotating at high speed to increase the amount of air blown.

The noise of the axial flow fan is caused by separation or vortex, or when the amount of air blown increases, a flow resistance occurs between the fan housing and the axial flow fan so that the noise increases.

In particular, when a specific band or the amount of air blown increases, the axial flow increases, and accordingly, the gas hits the blades, thereby generating flow resistance and thus increasing noise.

DISCLOSURE

Technical Problem

An object of the present invention is to provide a noise reduction-type impeller that reduces noise by allowing air to flow smoothly at a high power or in a specific band.

Another object of the present invention is to provide a noise reduction-type impeller capable of reducing noise while preventing a decrease in wind power by simultaneously implementing a first area part that generates wind power on one blade and a second area part that reduces flow resistance by facilitating air flow.

Another object of the present invention is to provide a noise reduction-type impeller capable of minimizing noise in a specific band by unevenly forming the shape of one blade arranged adjacent to another blade.

Technical Solution

According to an aspect of the present invention, there is provided a noise reduction-type impeller which is arranged at a passage part through which air of a fan housing passes and includes a hub and a plurality of blades radially formed on the outer surface of the hub, wherein each of the blades includes: a hub connection part connected to the hub; a first side surface part and a second side surface part formed at opposite side surfaces of the hub connection part; and an outer surface part connected to the end parts of a second connection part and the first side surface part and arranged to have a gap part which corresponds to a spacing from the inner surface of the passage part of the fan housing, and at least one of outer surface parts of the plurality of blades has a first area part, the gap part of which has a small area, and a second area part, the gap part of which has an area relatively larger than that of the first area part, wherein the first area part may perform a role of generating wind power, and the second area part may perform a role of reducing noise by reducing flow resistance.

The first area part of the blade outer surface part may be connected to an end part of the first side surface part, and the second area part may be connected to an end part of the second side surface part to form the first area part and the second area part on the outer surface part of one blade.

The first area part and the second area part may be formed to have the same radius of curvature and have different heights, so that the first area part and the second area part may be formed on the outer surface part of one blade.

The first area part may be connected to the first side surface part and the second side surface part to be located at both edges of the outer surface part, and the second area part may be located at the center of the outer surface part between the first area parts so that the first area part and the second area part may be formed on the outer surface part of one blade.

The plurality of blades include a second blade arranged adjacent to the first blade, and the outer surface of the first blade and the outer surface of the second blade have different shapes, thereby reducing noise in a specific area.

The first area part of the first blade is connected to the end of the first side surface part, the second area part of the first blade is connected to the second side surface part, the first area part of the second blade is connected to the second side surface part, and the second area part of the second blade is connected to the first side surface part, so that noise in a specific area can be reduced and noise during high power can be reduced.

The blades include a plurality of first blades and second blades each arranged between the first blades, and the length of the second blade is less than the length of the first blade, so that the outer surface part of the first blade may form the first area part, and the second blade may form the second area part.

Advantageous Effects

As described above, the impeller according to the present invention has a first area part and a second area part formed to have different heights on the outer surface of the blade, and to have different areas of the gap part to minimize fluid flow resistance while maintaining air blowing performance, thereby reducing noise.

In addition, noise in a specific band can be reduced by forming different shape of the outer surface of one blade from that of the outer surface of another blade placed adjacent to each other.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a fan housing and an impeller according to a first embodiment of the present invention.

FIG. 2 is a plan view of an impeller according to a first embodiment of the present invention.

FIG. 3 is a plan view of an impeller according to a second embodiment of the present invention.

FIG. 4 is a plan view of an impeller according to a third embodiment of the present invention.

FIG. 5 is a plan view of an impeller according to a fourth embodiment of the present invention.

FIG. 6 is a plan view of an impeller according to a fifth embodiment of the present invention.

FIG. 7 is a plan view of an impeller according to a sixth embodiment of the present invention.

FIG. 8 is a graph showing noise according to bands of an impeller according to the present invention.

BEST MODE

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The sizes and shapes of the components shown in the drawings may be exaggerated for clarity and convenience. In addition, terms defined in consideration of the configuration and operation of the present invention may vary depending on the intention or custom of the user, the operator, and the like. Definitions of these terms should be based on the content of this specification.

Referring to FIG. 1, the present invention may include a fan housing 10 in which a passage part 12 is formed so that air passes in an axial direction, and an impeller 20 arranged inside the passage part 12 of the fan housing 10 to flow gas in the axial direction.

The impeller 20 may include a hub 22 connected to a motor, and a plurality of blades 24 formed radially at regular intervals in the circumferential direction of the hub 22.

As shown in FIG. 2, the blade 24 may include a hub connection part 32 connected to the hub 22, first and second side surface parts 34 and 36 having a predetermined distance from adjacent blades, and an outer surface part 40 arranged to have a gap part 14, which is a spacing from the inner surface of the passage part 12 of the fan housing 10.

In such an impeller 20, when a specific band or the amount of air blown increases, the amount of air passing through the impeller 20 increases, and accordingly, air flow resistance is generated, thereby generating noise. Flow resistance is caused by an increase in air volume, or is generated when air that does not pass smoothly through the blade from the front of the blade 24 in a certain band, hit the blade, or a vortex occurs in the air that passes through the blade from the rear of the blade. As a result, noise may be generated as the air passing through the blade collides with the air generated by the vortex.

Therefore, this embodiment aims to provide an impeller that can minimize the deterioration of air blowing performance while reducing noise by minimizing flow resistance by changing the shape of the outer surface part 40 of the blade 24.

As shown in FIG. 2, the outer surface of the blade 20 according to a first embodiment is formed to have, on one blade 24, a first area part 42, formed to have a relatively smaller gap with the inner surface of the fan housing 10, the gap part 14 of which has a small area, and a second area part 44, formed to have a relatively larger gap with the inner surface of the fan housing 10, the gap part 14 of which has an area relatively larger than that of the first area part 42. That is, the first area part 42 with a small gap 14 and the second area part 44 with a relatively larger gap 14 compared to the first area part 42 are formed on one blade 24 so that air generated with flow resistance may pass smoothly through the second area part 44, and the first area part 42 may serve as a blade that generates wind power, to thereby minimize a drop in wind power and the occurrence of noise due to flow resistance.

The first area part 42 is connected to the end of the first side surface part 34 of the blade, and the second area part 44 is connected to the end of the second side surface part 36 of the blade, so that the first area part 42 and the second area part 44 are formed in a stepped shape with different heights, and accordingly, the outer surface part 40 of one blade may be divided into the first area part 42 and the second area part 44.

The first area part 42 and the second area part 44 are formed to have the same radius of curvature and are formed to have different heights so that the areas of the gap parts 14 are different from each other.

In this case, it is preferable that the length of the first area part 42 is formed less than the length of the second area part 44. That is, when the length L2 of the first area part 42 is greater than or equal to a set value, the blade does not significantly affect the air blowing performance, but the greater the length L1 of the second area part 44, the larger the area of the gap part 14, and accordingly, the air may flow smoothly, thereby improving noise reduction performance.

Of course, the length of the first area part 42 may be formed greater than that of the second area part 44, or the length of the first area part 42 and the length of the second area part 44 may be formed the same.

In this way, the first area part 42 and the second area part 44 are integrally formed on the outer surface part 40 of one blade 24 to minimize the occurrence of noise by minimizing the flow resistance by the second area part 44 while maintaining the air blowing performance by the first area part 42.

As shown in FIG. 3, the outer surface part 50 of the blade according to a second embodiment has first area parts 52 and 54 formed at both edges of the outer surface part 50 of the blade, and a second area part 56 formed at the center of the outer surface part 50 of the blade. The first area parts 52 and 54 are located on both parts of the outer surface part 50 connected to the first side surface part 34 and the second side surface part 36 of the blade 24, and the second area part 56 is formed between the first area parts 52 and 54.

In the impeller according to the second embodiment, a sum of lengths of the first area parts 52 and 54 formed on both sides of the outer surface part of the blade 24 may be formed less than the length of the second area part 56 formed in the center of the outer surface part 50 of the blade 24.

The impeller according to the second embodiment minimizes flow resistance as air passes through the first area parts 52 and 54 located on both sides of the outer surface part of the blade, and generates wind power by the second area part 56 located at the center of the outer surface part 50 of the blade 24.

As shown in FIG. 4, an outer surface part 60 of a blade 24 according to a third embodiment has a first area part 62 formed at the center of the outer surface part 60 of the blade 24, and second area parts 64 and 66 formed at both edges of the outer surface part 60 of the blade 24. The second area parts 64 and 66 according to the third embodiment are located on both parts of the outer surface part 60 connected to the first side surface part 34 and the second side surface part 36 of the blade, and the first area part 62 may be formed between the second area parts 64 and 66.

A plurality of blades according to a fourth embodiment include a first blade 70 and a second blade 72 arranged adjacent to the first blade 70, as shown in FIG. 5, and an outer surface part 80 of the first blade 70 and an outer surface part 90 of the second blade 72 may have different shapes. That is, the outer surface part 80 of the first blade 70 and the outer surface part 90 of the second blade 72 may be non-uniformly formed.

By forming different shapes of the outer surface part 80 of the first blade 70 and the outer surface part 90 of the second blade 72, noise may be simultaneously minimized during high power and in a specific band. In other words, when the shapes of the outer surface part 80 of the first blade 70 and the outer surface part 90 of the second blade 72 are formed differently, the air flow in a specific band is facilitated, thereby minimizing noise generation in a specific band as well as minimizing noise generation at high power.

The outer surface part 80 of the first blade 70 may include a first area part 84 connected to the second side surface part 36 and a second area part 82 connected to the first side surface part 34, and the outer surface part 90 of the second blade 72 may include a first area part 94 connected to the first side surface part 34 and a second area part 92 connected to the second side surface part 36. That is, the first area part 84 and the second area part 82 of the first blade 70 and the first area part 94 and the second area part 92 of the second blade 72 may be formed opposite to each other to have non-uniform shapes.

For example, when the number of blades is 6, three blades may be formed in the shape of the outer surface part 80 of the first blade 70, and the remaining three blades may be formed in the shape of the outer surface part 90 of the second blade 72 and arranged between the first blades 70.

A blade according to a fifth embodiment includes, as shown in FIG. 6, a first blade 110 and a second blade 120 arranged adjacent to the first blade 110. An outer surface part 130 of the first blade 110 includes first area parts 134 and 136 connected to the first side surface part 34 and the second side surface part 36 of the first blade 110, and a second area part 132 positioned at the center of the outer surface part 130 of the first blade 110, and an outer surface part 140 of the second blade 120 may include second area parts 142 and 144 connected to the first side surface part 34 and the second side surface part 36 of the second blade 120, and a first area part 146 positioned at the center of the outer surface part 140 of the second blade 120.

In the plurality of blades according to the fifth embodiment, the first blades and the second blades may be formed in the same number, and the second blade may be arranged between the first blades.

A blade according to a sixth embodiment includes, as shown in FIG. 7, a plurality of first blades 200, and a plurality of second blades 210 arranged between the plurality of first blades 200, wherein the length H1 of the first blade 200 is formed as long as possible, and the length H2 of the second blade 210 is formed to be less than the length H1 of the first blade 200, such that an outer surface part of the first blade 200 and an outer surface part of the second blade 210 are formed unevenly.

In other words, a first area part is formed on the outer surface part of the first blade 200, and a second area part is formed on the outer surface part of the second blade 210. It is possible to minimize noise generation due to flow resistance by performing the natural role of the blades while minimizing the decrease in wind power by allowing air that generates flow resistance to pass smoothly through the second area part formed between the outer surface part of the second blade 210 and the fan housing.

FIG. 8 is a graph showing the noise for each band of the impeller according to the first to sixth embodiments of the present invention, and it may be seen that the noise is reduced in a specific band H of 700 Hz.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, by way of illustration and example only, it is clearly understood that the present invention is not to be construed as limiting the present invention, and various changes and modifications may be made by those skilled in the art within the protective scope of the invention without departing off the spirit of the present invention.

INDUSTRIAL APPLICABILITY

The present invention relates to an axial flow fan in which air is sucked in an axial direction and discharged in the axial direction, and the shapes of the outer surfaces of the blades are unevenly formed to facilitate the flow of air, thereby reducing noise.