JP2002257089A - Propeller fan and blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a propeller fan sending air in an axial direction capable of simply providing a velocity triangle close to an actual streamline. SOLUTION: This propeller fan sends air in the axial direction and is provided with a hub 15a and plural blades 15b. The hub 15a is positioned in a center. The plural blades 15b extend from the hub 15a to outer circumference side and include a rising part 33 rising toward a positive pressure surface side further than other trailing edge part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propeller fan that blows air in an axial direction and a blower that takes in air from the outside and discharges the air to the outside.

[0002]

2. Description of the Related Art An outdoor unit of an air conditioner is known as an example of a blower using a propeller fan for blowing air in an axial direction. The outdoor unit generally includes a casing having an air introduction section for introducing air from outside, a heat exchange section arranged facing the air introduction section inside the casing, and a propeller arranged at, for example, an upper portion of the casing. It has a fan and a drive unit for driving the propeller fan.

[0003] When designing a propeller fan used in this type of blower, three-dimensional blade surface coordinates can be easily generated. Therefore, conventionally, a streamline and a speed triangle along the axial direction of the propeller fan have been conventionally determined. The design method used is often used.

[0004]

When the differential pressure across the propeller fan is small, such as in a ventilation fan or an electric fan, the streamline runs along the axial direction. For this reason, even if the propeller fan is designed by the conventional design method using such an axis along the axial direction and the speed triangle, no problem is likely to occur. However, when a propeller fan is arranged in a casing like an outdoor unit, the differential pressure across the propeller fan increases,
The streamline tends to spread on the exit side. For this reason, in the conventional design method, the exit angle (velocity triangle) of the blade does not match the actual streamline, and the air volume and the like may not satisfy required performance.

[0005] It is considered that the above problem can be solved by analyzing and designing streamlines by three-dimensional analysis. However, although a design method based on three-dimensional analysis can be expected to have high accuracy, it requires a lot of time and cost, and thus has a practical problem.

An object of the present invention is to make it possible to easily obtain a propeller fan that has a velocity triangle close to an actual streamline in a propeller fan that blows in the axial direction. Another object of the present invention is to make it possible to easily satisfy required performance in a blower having a propeller fan.

[0007]

A propeller fan according to claim 1 is a fan that blows air in an axial direction, comprising: a hub;
And a plurality of blades. The hub is centrally located. The plurality of blades extend from the hub to the outer peripheral side, and have an upright portion on the outer peripheral side of the trailing edge toward the pressure side from the other trailing edge portion.

The propeller fan has an upright portion on the outer peripheral side of the trailing edge portion of the plurality of blades toward the pressure surface. Here, by providing an upright portion and raising it from the other portion toward the positive pressure side according to how the streamline spreads on the outer peripheral side of the trailing edge, the rising portion matches the actual streamline speed triangle. Can be. For this reason, it is possible to easily obtain one having a velocity triangle close to the actual streamline.

A propeller fan according to a second aspect is the fan according to the first aspect, wherein the upright portion has a shape in which the outer peripheral side of the trailing edge increases by a predetermined angle when the blade is projected on a meridional plane. In this case, by bending the outer peripheral portion of the trailing edge of the blade having a curved shape obliquely inclined with respect to the axis, the shape can be increased by a predetermined angle when projected on the meridian plane. Is easy to form.

According to a third aspect of the present invention, there is provided the propeller fan according to the first or second aspect, wherein the upright portion gradually increases as the distance from the trailing edge to the portion where the upright portion starts to rise is closer to the outer peripheral side. It is formed to be large. In this case, an upright portion having a shape corresponding to the speed triangle can be easily formed.

A propeller fan according to a fourth aspect of the present invention is the fan according to any one of the first to third aspects, wherein the upright portion has a length not more than 2/3 of the total length of the rear edge from the outer peripheral side of the rear edge. Have been. In this case, the upright portion can be efficiently provided only in the portion where the streamline toward the outer peripheral side is generated.

According to a fifth aspect of the present invention, there is provided a blower for taking in air from the outside and discharging the air to the outside, comprising a casing, a propeller fan, and a drive unit. The casing has an air introduction part into which air from outside can be introduced. The propeller fan is a fan according to any one of claims 1 to 4, which is arranged in a casing and discharges the introduced air to the outside. The drive unit drives the propeller fan.

In this blower, when the propeller fan is rotated by the drive unit, air is taken into the casing from the air introduction unit by the propeller fan, and the air is discharged to the outside by the propeller fan. At this time, the streamline spreads radially outward from the inside of the casing, and the air flows. However, the blades having a shape close to the streamline speed triangle are set by the upright portions, so that the required performance can be easily satisfied.

According to a sixth aspect of the present invention, in the air blower according to the fifth aspect, the propeller fan is arranged at an upper portion in the casing, and discharges air upward from the inside of the casing. In this case, even with a blower of a type having a relatively large pressure difference before and after the fan, the required performance can be easily satisfied.

According to a seventh aspect of the present invention, in the air blower according to the fifth or sixth aspect, the casing has a projection at an upper portion projecting upward so as to accommodate a propeller fan. In this case, since the propeller fan is arranged in the protruding portion, the gap on the outer peripheral side of the propeller fan is reduced, and the air taken in from the outside can be efficiently discharged to the outside.

According to an eighth aspect of the present invention, in the air blower according to the seventh aspect, the projecting portion is formed in a cylindrical shape with a rounded surface having a rounded vertical cross section with a gradually decreasing diameter toward the upper part of the casing. The cylindrical portion is formed into a cylindrical shape with a reduced diameter portion, a cylindrical portion formed into a cylindrical shape from the reduced diameter portion, and a round surface whose diameter gradually increases upward from the cylindrical portion and has a rounded vertical cross section. And an enlarged diameter portion at an intermediate portion. In this case, it becomes easier for the air to flow into the fan on the radius surface on the reduced diameter portion side, and the flow resistance can be reduced. In addition, the flow can be made to spread straight along the radial direction, especially when the wind speed drops, against the expanding flow blown out from the fan on the radius surface on the enlarged diameter part side, and the resistance on the blowing side can also be reduced. it can.

[0017]

1 to 3, an outdoor unit (an example of a blower unit) 10 of an air conditioner employing an embodiment of the present invention introduces outside air from a side surface and removes the introduced outside air. It is a top-blowing type that blows upward by exchanging heat with the refrigerant. The outdoor unit 10 includes a casing 11
And a heat exchange unit 12 disposed in the casing 11, a control unit 13 disposed in the casing 11 so as to face the heat exchange unit 12, and a blower fan according to an embodiment of the present invention for taking in and blowing out outside air. 15, a fan guard 18 fitted in the casing 11, and a compressor 19 for compressing the refrigerant.

The casing 11 has a rectangular parallelepiped casing main body 16 with an upper opening, and an upper lid member 17 placed on the opening of the casing main body 16. The casing body 16 is a member made of a thin metal plate formed by, for example, sheet metal working, and has a side wall 20a facing the control unit 13 and a part of the side walls 20b, 20b on both sides thereof, and has outside air introduction having a large number of rectangular openings. It has openings 21a and 21b, and has a space 22 inside.

The upper lid member 17 is an integrally formed member made of a synthetic resin, in which a bell mouth 14 having a substantially cylindrical shape and having an upper and lower portion widened is formed. As shown in FIG. 3, the center position O1 of the bell mouth 14 is eccentric to the control unit 13 side from the center position O2 of the casing body 16.
The upper lid member 17 has a rectangular outer shape and has a casing body 16.
And a middle portion 17b in which a bell mouth 14 narrowed cylindrically from the placement portion 17a is formed.
It has a circular guard mounting portion 17c extending from the intermediate portion 17b. The bell mouth 14 has a rectangular mounting portion 17a.
A diameter-reduced portion 14a formed in a cylindrical shape with a rounded surface having a radius R1 and a vertical cross-section gradually reduced from above;
A cylindrical portion 14b formed in a cylindrical shape from the reduced diameter portion;
The enlarged diameter portion 14c gradually increases in diameter upward from 4b and has a cylindrical section formed with a rounded radius surface having a radius R2.
And The lower reduced diameter portion 14a is
5 is provided in order to reduce the inflow resistance. The upper enlarged diameter portion 14c is provided in order to reduce the resistance of the blower fan 15 to the spreading and blowing flow. In other words, by forming the enlarged diameter portion 14c having this round surface, the flow of the blowout flow can be straightened in the radial direction not immediately after blowing at a high wind speed, but at a time when the speed drops below this. Thus, the resistance on the blowing side can be reduced.

As shown in FIGS. 1 to 3, the blower fan 15 is a propeller fan having a centrally located hub 15a and a plurality of blades 15b provided around the hub 15a. Located inside. The blower fan 15 is driven to rotate by a motor 31 fixed to the casing body 16. The hub 15a is a cylindrical member, and a motor 31 is non-rotatably mounted on the hub 15a.

The blade 15b extends from the hub 15a to the outer peripheral side, and has an upright portion 33 on the outer peripheral side of the trailing edge 32, which is closer to the positive pressure surface side (blow-out side, the near side in the direction perpendicular to the paper of FIG. 3) than the other trailing edge. Have. As shown in FIG. 4, the upright portion 33 has a shape in which the outer peripheral side of the trailing edge 32 increases by a predetermined angle θ2 when the blade 15b is projected on the meridional plane. That is, as shown in FIG. 5, when the trailing edge 32 of the blade 15b that is curved while being inclined from the trailing edge 32 to the leading edge is bent, the bent outer trailing edge 32 (the upright portion 33) is bent.
Is increased by a predetermined angle θ2 with respect to the trailing edge 32 on the inner peripheral side and is projected on the meridional plane. FIG. 5 is the same as FIG.
It is sectional drawing by the cutting line V in the same radial position. The upright portion 33 is formed such that the distance D from the trailing edge 32 to the bent portion 33a where the upright portion 33 starts to rise gradually increases toward the outer peripheral side. Further, the upright portion 33 is formed from the outer peripheral side of the rear edge 32 to the entire length L of the rear edge 32.
/ 3 or less. Specifically, as shown in FIGS. 4 and 5, the upright portion 33 has the same angle θ1 as the divergence angle θ1 of the streamline F from the rear edge 32 of the blade 15b, for example, toward the outer peripheral side from the center to the outer peripheral side. The rear edge 32 is formed by bending so as to form a desired speed triangle.

The streamline in the blower fan 15 is a swirl-spreading flow having a speed component of a predetermined magnitude in the rotation direction and the axial direction of the blower fan. For this reason, the blade 15 designed by the conventional design method using the streamline in the axial direction and the speed triangle is used.
b, and the outer peripheral side of the trailing edge 32 is erected from another part toward the positive pressure side in accordance with the degree of spread of the streamline, so that the erected part is the actual streamline speed. Can fit triangles. Moreover, the spread angle θ1
And the upright portion 33 is formed, so that the one having a speed triangle close to the actual streamline can be easily obtained. Further, since the distance D from the trailing edge 32 to the bent portion 33a where the rising of the upright portion 33 begins to rise gradually increases toward the outer peripheral side, the upright portion having a shape corresponding to the speed triangle can be easily formed. Can be formed. further,
The upright portion 33 extends from the outer peripheral side of the rear edge 32 to the entire length L of the rear edge 32.
Since it is formed with a length of 2/3 or less, the upright portion 33 can be efficiently provided only in a portion where a streamline toward the outer peripheral side is generated.

The fan guard 18 includes a closing plate 25 located at the center, an outer frame 26 located at the outer periphery, a plurality of curved radial ribs 27 connecting the closing plate 25 and the outer frame 26, An annular rib 28 annularly arranged between the frame 26
And The fan guard 18 is made of, for example, an integrally molded synthetic resin. The closing plate 25 is a circular portion having a larger diameter than the hub 15 a of the blower fan 15. Outer frame 2
Reference numeral 6 denotes a sleeve-shaped portion having a diameter larger than the outer diameter of the blade 15b of the blower fan 15. This outer frame 26 is the guard mounting portion 1
The fan guard 18 is fitted into the upper lid member 17 by being fitted in 7c.

The heat exchange section 12 has a large number of cooling fins, and has an outside air introduction port 21 a in the casing 11.
The cooling medium flows through the inside and is exchanged with the introduced air by being arranged on the side walls 20a and 20b having the 21b. For example,
During cooling, heat is exchanged between the refrigerant condensed in the indoor unit and the introduced air to warm the air. In addition, at the time of heating, the introduced air exchanges heat with the compressed high-temperature and high-pressure refrigerant to cool the air.

The control unit 13 controls the compressor 19 and the blower fan 15 of the outdoor unit 10 according to the room temperature and the operation mode. The compressor 19 compresses the refrigerant to a high temperature and a high pressure, and cools and heats the indoor unit heat exchanger (not shown) and the heat exchange unit 1.
2 and send it out.

In the outdoor unit 10 configured as described above, when the blower fan 15 rotates, the outside air inlet 21a,
Air passes through the heat exchange section 12 and is introduced into the casing 11 via 21b. The introduced air is blown to the outside by the blower fan 15 through the fan guard 18.

At this time, since the upright portion 33 is formed on the outer peripheral side of the trailing edge 32 of the blade 15b, a desired velocity triangle can be formed with respect to an actual streamline extending on the outer peripheral side. For this reason, the exit angle of the blade 15b can be adapted to the actual streamline, and the required performance can be accurately satisfied by a simple design method.

[Other Embodiments] (a) In the above embodiment, the upright portion 33 is formed by bending the trailing edge 32, but the upstanding portion may be formed by bending the trailing edge.

(B) In the above embodiment, the present invention has been described by taking as an example a blower fan mounted on an outdoor unit for an air conditioner with a top blow, but the blower fan of the present invention can be applied to all blowers. .

[0030]

According to the first aspect of the present invention, the upright portion is provided to be raised from another portion toward the positive pressure side on the outer peripheral side of the trailing edge in accordance with the spread of the streamline, so that the upright portion is formed. It can be fitted to the actual streamline velocity triangle. Therefore, it is possible to easily obtain one having a velocity triangle close to the actual streamline.

According to the second aspect of the present invention, the outer peripheral portion of the trailing edge can be bent to have a shape that increases by a predetermined angle when projected on the meridian plane, so that the upright portion can be easily formed.

According to the third aspect of the present invention, it is possible to easily form the upright portion having a shape corresponding to the speed triangle. According to the fourth aspect of the present invention, the upright portion can be efficiently provided only in the portion where the streamline toward the outer peripheral side is generated.

According to the fifth aspect of the present invention, although the stream flows from the inside of the casing to the outside in the radial direction and the air flows, the blade having a shape close to the speed triangle of the stream line is set by the upright portion, so that it is easy to use. The required performance can be satisfied.

According to the sixth aspect of the invention, the required performance can be easily satisfied even with a blower of a type having a relatively large pressure difference before and after the fan. In the invention according to claim 7,
Since the propeller fan is disposed in the protruding portion, the gap on the outer peripheral side of the propeller fan is reduced, and the air taken in from the outside can be efficiently discharged to the outside. In the blower according to the eighth aspect, the air easily flows into the fan on the round surface on the reduced diameter portion side, and the flow resistance can be reduced. In addition, the flow can be made to spread straight along the radial direction when the wind speed drops, especially for the expanding flow blown out from the fan on the radius surface of the enlarged diameter part side, and the resistance on the blowing side can also be reduced. it can.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view of an outdoor unit of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a partially exploded perspective view of the upper part of the outdoor unit.

FIG. 3 is a sectional view taken along the line III-III of FIG. 1;

FIG. 4 is an enlarged partial view of a blower fan.

FIG. 5 is a sectional view taken along the line V in FIG. 2;

[Explanation of symbols]

 Reference Signs List 10 outdoor unit 11 casing 14 bellmouth 14a reduced diameter portion 14b cylindrical portion 14c enlarged diameter portion 15 blower fan 15a hub 15b blade 17 upper lid member 17b intermediate portion 31 motor 32 trailing edge 33 upright portion 33a bent portion

Claims (8)

[Claims] A propeller fan for blowing air in an axial direction.
A hub (15a) located at the center, and an upstanding portion (33) extending from the hub (15a) to the outer peripheral side, and toward the outer peripheral side of the trailing edge 32 toward the positive pressure surface side from the other trailing edge portion. A propeller fan (15) including a plurality of blades (15b). 2. The upright portion (33) is provided with the blade (15).
The propeller fan (15) according to claim 1, wherein the outer peripheral side of the trailing edge (32) has a shape that increases by a predetermined angle when b) is projected on the meridional plane. 3. The upright portion (33) such that the distance from the trailing edge (32) to the portion (33a) where the upright portion (33) starts to rise gradually increases toward the outer peripheral side. The propeller fan (15) according to claim 1 or 2, wherein the propeller fan (15) is formed. 4. The upright portion (33) is connected to the trailing edge (32).
The propeller fan (15) according to any one of claims 1 to 3, wherein the propeller fan (15) is formed to have a length not more than 2/3 of a total length of the trailing edge from an outer peripheral side of the propeller fan. 5. A blower (10) for taking in air from the outside and discharging it to the outside, comprising: a casing (11) having an air introduction portion capable of introducing the outside air; and an inside of the casing (11). The propeller fan (15) according to any one of claims 1 to 4, wherein the propeller fan (15) is disposed at a position to discharge the introduced air to the outside, and a driving unit (31) that drives the propeller fan (15).
And a blower (10) comprising: 6. The propeller fan (15) is disposed at an upper portion in the casing (11), and discharges the air upward from the inside of the casing (11).
(10). 7. The casing (11) has a protruding portion (1) projecting upward so as to accommodate the propeller fan (15).
The blower according to claim 5 or 6, wherein the blower has (7) at an upper portion. 8. A reduced diameter portion (17) formed into a cylindrical shape with a radiused surface having a rounded vertical cross-section at an upper portion of the casing (11) and gradually reduced in diameter upward. 14
a), a cylindrical portion (14b) formed in a tubular shape from the reduced diameter portion (14a), and a round surface whose diameter is gradually increased upward from the cylindrical portion (14b) and whose longitudinal section is rounded. The blower according to claim 7, wherein the blower has a diameter-enlarging portion (14 c) formed in a cylindrical shape at an intermediate portion (17 b).