JP2003148395A - Air-conditioning blower impeller - Google Patents

Abstract

(57) [Abstract] [Problem] To improve the static pressure efficiency of an air conditioner impeller. A cross section of a blade in a radial direction is formed around a midpoint.
On the outer circumferential side from E, the curve is concave toward the windward side, and near the midpoint, the hub 3 side is configured as a convex curve toward the windward side. On the other hand, the radius of curvature of the concave curve is increased from the radial cross section AO on the leading edge side of the blade to the radial cross section CO near the trailing edge of the blade. It was done.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner fan impeller provided with blades used in a fan such as an air conditioner, and more particularly to the shape of the impeller blades.

[0002]

2. Description of the Related Art A conventional air-conditioning fan impeller 21 having thin blades has a structure as shown in FIGS. Similarly, the blades 24 made of a plurality of thin blades are radially provided around the hub 25 having a substantially truncated cone shape.

The front edge 22 of the blade 24 is provided with a hub 25 in FIG. 6 which is a shape diagram of the rotation locus of the air conditioner blower impeller 21.
Near the midpoint between the outer periphery of the blade and the outer edge 23 of the blade 24 (FF)
The curve is concave on the windward side on the outer peripheral side, and is convex on the windward side on the hub side near the midpoint. Further, not only the front edge 22 of the blade 24, but also the radial cross-sectional shape of the blade 24 is a concave curve with respect to the windward side on the outer peripheral side from the vicinity of the midpoint, and on the hub 26 side from the vicinity of the midpoint. It is composed of a convex curve with respect to the windward side. However, the radius of curvature r ₄ shown in FIG. 7 of the curve that is concave toward the windward side on the outer peripheral side from the vicinity of the midpoint is approximately the same value at any radial cross-section of the air conditioning fan impeller 21. At, the impeller was configured.

[0004]

However, in the above-described conventional configuration, the cross-sectional shape of the blade 24 in the radial direction is
The radius of curvature r ₄ of a curve that is concave with respect to the windward side on the outer peripheral side from the vicinity of the midpoint (F-F) is the blower impeller 2 for air conditioning.
Since the impeller was configured to have approximately the same value in any of the radial cross-sections of 1, when the blower was operating,
There is a limit to the control of the blade tip vortex that is generated near the outer peripheral edge 23 side of the blade 24 and separates from the suction surface of the blade near the trailing edge.

The present invention has been made to solve such a conventional problem, and an object thereof is to provide an air conditioner blower impeller for improving the static pressure efficiency of the impeller.

[0006]

In order to achieve the above object, the present invention has an impeller shape that does not restrain a blade tip vortex that separates from the suction surface of the blade near the trailing edge. That is, a plurality of blades are provided around the hub, and the radial cross-sectional shape of the blade is a concave curve on the windward side on the outer peripheral side and a convex curve on the windward side on the hub side. In an air-conditioning fan impeller, the concave curve on the outer peripheral side has a substantially arcuate shape, and its radius of curvature increases as the radial cross section goes from the leading edge side to the trailing edge side. is there.

Further, when the cross section of the blade leading edge side, the vicinity of the center of the chord length, and the blade trailing edge side are taken up as representative values of the radial cross section, the respective radii of curvature increase in this order.

The ratio of the curvature radii on the trailing edge side of the blade and the leading edge side of the blade is at least doubled. further,
The leading edge of the blade has the shape of the locus of rotation of the impeller, and the outer peripheral side has a concave curve with respect to the windward side.

Due to the leakage flow from the pressure surface on the leeward side of the blade toward the suction surface on the upwind side through the gap between the outer peripheral edge of the blade and the casing, the blade tip vortex generated on the suction surface near the outer periphery of the blade is generated by the rotation of the blade. In the process of flowing from the leading edge side to the trailing edge side in the opposite direction, it is separated from the suction surface in the vicinity of the trailing edge, but with the above configuration, the trailing edge side has a small curvature, that is, a large radius of curvature in the impeller shape of the present invention. , When the tip vortex separates from the suction surface near the trailing edge, the tip vortex separates without interfering with the impeller shape. That is, since the separation of the blade tip vortex is not hindered by the concave portion near the trailing edge, aerodynamic loss does not occur in the separation of the blade tip vortex. Therefore, the efficiency of the air conditioning blower can be improved.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, the leading edge of the blade is concaved to the windward side on the outer peripheral side from the vicinity of the midpoint between the hub and the outer peripheral end of the blade in the shape of the rotation locus of the air conditioning fan impeller. The curve of the shape is configured to have a convex curve toward the windward side near the hub near the midpoint, and the radial cross-sectional shape of the blade is set to the windward side near the outer circumference near the midpoint. The air-conditioning fan impeller has a concave curved line that is convex toward the windward side near the midpoint and is concave toward the windward side near the midpoint. The radius of curvature of the curve becomes larger in the order of the radial cross section on the leading edge side of the blade, the radial cross section near the center of the chord length of the blade, and the radial cross section near the trailing edge of the blade. Then, it is configured.

With the above structure, the generation of blade tip vortices generated on the suction surface near the outer circumference of the blade due to the leakage flow from the pressure surface of the blade to the suction surface is promoted by the above-mentioned concave curved portion of the blade itself to reduce Noise can be achieved. That is, although the blade tip vortex is generated on the suction surface of the blade, it separates from the suction surface of the blade at a position closer to the trailing edge than near the center of the chord length of the blade. The radius is configured so that the value increases in the order of the radial cross section on the leading edge side of the blade, the radial cross section near the center of the chord length of the blade, and the radial cross section near the trailing edge of the blade. Therefore, the separation phenomenon of the blade tip vortex is not hindered. As a result, the peeling loss is reduced and the efficiency can be further improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An air conditioning fan impeller of the present invention will be described below with reference to FIGS. FIG. 1 is a plan view of an air-conditioning fan impeller, FIG. 2 is a partial view showing a rotation locus of the impeller, and FIG. 3 (a) is a front edge side radial cross-sectional view of the impeller (A-O cross section of FIG. 1). ), FIG. 3B is a radial cross-sectional view (cross-sectional view taken along the line B-O of FIG. 1) near the center of the chord length of the blade of the impeller, and FIG. Figure (C in Figure 1
-O cross section), FIG. 4 is a schematic diagram showing an operating state of the impeller,
Further, FIG. 5 is a schematic view showing a state of a tip vortex of the impeller.

As shown in FIG. 1, an air conditioner blower impeller 1
Is provided with three blades 2 each having a thin cross section in a radial shape centering on a hub 3 having a substantially truncated cone shape. Then, as shown in FIG.
The motor 1 is attached to the center of the rotation axis of the hub 3 of the fan impeller 1 for air conditioning.
The shaft of No. 0 is fixed, and is housed in an appropriate casing 9 along the rotation locus of the outer peripheral edge of the blade, and is rotated by the motor 10 to generate the air blowing action.
At this time, most of the air flows in from the front edge 4 of the blade 2 shown in FIG. 1 and flows out from the rear edge 5 to perform aerodynamic work.

Here, as shown in FIG. 2, the leading edge 4 of the blade 2 is
Is a midpoint line EE between the root of the blade 2 to the hub 3 and the outer peripheral end 6 of the blade 2 in the shape of the rotation trajectory of the air conditioner blower impeller.
On the outer peripheral side of the vicinity, the curve is concave with respect to the windward side, and on the hub 3 side with respect to the vicinity of the midpoint line EE, the curve is convex with respect to the windward side. Line D-D indicates the center line of rotation of the impeller.

Further, as shown in FIGS. 3 (a), 3 (b) and 3 (c), the radial cross-sectional shape of the blade 2 is represented by a midpoint line E--
The outer peripheral edge 6 side from the vicinity of E is a concave curve to the windward side, and the hub 3 side from the midpoint line EE is a convex curve to the windward side. In addition, the radius of curvature of the curve that is concave with respect to the windward side on the outer peripheral side from the vicinity of the midpoint line EE is the radius of the leading edge 4 side of the blade 2 in the radial cross section, the radius near the center of the chord length of the blade 2. The directional cross section and the radial cross section near the trailing edge 5 of the blade 2 are arranged in the order of increasing value. That is, the radius of curvature of the radial cross section on the leading edge 4 side of the blade 2 is r ₁ , the radius of curvature of the radial cross section near the center of the chord length of the blade 2 is r ₂ , the radius near the trailing edge 5 of the blade 2. When the radius of curvature of the directional cross section is r ₃ , the relationship of the magnitudes of the radius of curvature is r ₁ <r ₂ <r ₃ .

The above-described relationship of the magnitude of the radius of curvature has been described by typifying three radial cross-sections, but the radius of curvature at any radial cross-section includes the above three points in relation to the position of the cross-section. It is natural from the viewpoint of aerodynamics that it can be smoothly interpolated.

With the above-described structure, as shown in FIGS. 3 and 5, from the pressure surface 8 of the blade 2 on the leeward side to the negative pressure surface 7 on the windward side, between the outer peripheral edge 6 of the blade and the casing 9. There is a leak flow through. As a result, the generation of the blade tip vortex 11 generated on the suction surface 7 near the outer periphery of the blade 2 is promoted by the above-mentioned concave curved portion of the blade 2 itself, and the noise can be reduced. However, although the blade tip vortex 11 is generated on the suction surface 7 of the blade, in the conventional blade shape, the blade tip vortex 11 tends to separate from the suction surface 7 of the blade at a position closer to the trailing edge 5 than the vicinity of the center of the chord length of the blade 2. It is in. However, in the present embodiment, as described above, the radius of curvature of the curved curve is the radial cross-section of the blade 2 on the front edge 4 side,
Radial cross section near the center of chord length of wing 2, trailing edge 5 of wing 2
The radius of curvature r ₃ on the radial cross-section side near the trailing edge 5 of the blade 2 is made sufficiently large by increasing the values in the order of the radial cross-section near the concave section near the trailing edge. Does not hinder the separation phenomenon of the blade tip vortex 11. Therefore, the loss due to vortex separation is reduced and the efficiency can be further improved.

The following is the data comparing the conventional impeller and the impeller according to the present invention in the outdoor unit of the air conditioner composed of the heat exchanger, the front grill and the compressor.

Both the conventional type and the impeller of the present invention have two blades, the outer diameter of the blade is 415 mm, and the outer diameter on the windward side of the boss is 104 m.
m, the outer diameter on the leeward side of the boss was 161 mm, and a comparative experiment was conducted.

The blade shape of the conventional impeller used was such that the radius of curvature was constant at the leading edge side, near the center, and at the trailing edge side of the radial cross section, and all were about 130 mm.
In the blade shape of the impeller according to the present invention, the radius of curvature on the leading edge side of the radial cross section is about 130 mm, which is the same as the conventional one, for comparison, and the radius of curvature on the trailing edge side is about 3 mm.
It was set to 20 mm, and the radius of curvature in the middle was used in the vicinity of the center.

When the operating point efficiencies of the above impellers are compared by experiments, the air conditioner blower impeller according to the present invention is improved by about 10% as compared with the conventional type. Also,
The number of blades of the air conditioner blower impeller 1 may be two, three, or four, and is generally plural.

[0022]

As is apparent from the above-described embodiments, the present invention provides that the leading edge of the blade is formed around the midpoint between the hub and the outer peripheral end of the blade in the shape of the rotation locus of the air conditioner fan impeller. Side, the curve is concave to the windward side, and the hub side is convex to the windward side from the midpoint, and the radial cross section of the blade is An air-conditioning fan impeller with a concave curve to the windward side on the outer peripheral side and a convex curve to the windward side from the midpoint on the hub side. The radius of curvature of the curve that is concave with respect to the windward side is from the radial cross section near the leading edge of the blade to the radial cross section near the trailing edge of the blade through the radial cross section near the center of the chord length of the blade. It is configured so that its value becomes larger as it reaches.

With the above structure, the generation of the tip vortex generated on the suction surface near the outer periphery of the blade due to the leakage flow from the pressure surface of the blade to the suction surface is promoted by the concave curved portion of the blade itself to reduce the Noise can be achieved. The tip vortex is generated on the suction surface of the wing, but since the separation phenomenon of the tip vortex from the suction surface of the wing is not obstructed at a position closer to the trailing edge than near the center of the chord length of the wing, the aerodynamics associated with the separation The loss is reduced and the efficiency can be further improved.

[Brief description of drawings]

FIG. 1 shows a plan view of an air conditioner blower impeller according to an embodiment of the present invention.

FIG. 2 is a partial view showing a rotation trajectory of the impeller.

FIG. 3 (a) is a radial cross-sectional view of the impeller on the leading edge side (cross section AO of FIG. 1), and FIG. 3 (b) is a radial cross-sectional view near the center of the chord length of the impeller. (B-O cross section of FIG. 1) is shown, (c) shows the trailing edge side radial direction cross section of the same impeller (C-O cross section of FIG. 1).

FIG. 4 is a schematic diagram showing an operating state of the impeller.

FIG. 5 is a schematic diagram showing a state of a tip vortex of the impeller.

FIG. 6 is a partial view showing a rotation trajectory of a conventional air conditioner blower impeller.

FIG. 7 is a radial cross-sectional view of a conventional air conditioner blower impeller.

[Explanation of symbols]

1 Air conditioning blower impeller 2 wings 3 hub 4 Leading edge 5 trailing edge 6 Outer edge 7 Suction surface 8 Pressure side

Claims (4)

[Claims] 1. A plurality of blades are provided around a hub, and a radial cross-sectional shape of the blades is a curved line having a concave shape on the outer peripheral side with respect to the windward side and a convex shape with respect to the windward side on the hub side. In an air-conditioning fan impeller configured by a curved line, the concave-shaped curve on the outer peripheral side has a substantially arc shape, and as the radial cross section goes from the leading edge side to the trailing edge side of the blade, the value of the radius of curvature is A blower impeller for air conditioning, which is characterized by becoming large. 2. The radius of curvature increases in the order of the radial cross section on the leading edge side of the blade, the radial cross section near the center of the chord length of the blade, and the radial cross section on the trailing edge side of the blade. The fan impeller for air conditioning according to claim 1, 3. The air-conditioning fan impeller according to claim 1, wherein the radius of curvature of the blade on the trailing edge side in the radial cross section is at least twice the radius of curvature of the blade on the leading edge side. 4. The air conditioner blower impeller according to claim 1, wherein the blade has a leading edge formed in a shape of a rotational locus of the impeller and a concave curve on the outer peripheral side with respect to the windward side. .