JP2001304185A - Blower impeller and air conditioner provided with the blower impeller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently carry out an aerodynamic work even to a radial flowing-in of two suction flows of an axial flowing-in and a radial flowing-in and to sufficiently enhance a stationary pressure efficiency of a blower by making a shape of rotation track figure (meridian) of the impeller the most appropriate in a blower impeller. SOLUTION: The blower impeller is provided with an impeller 1 driven by a motor. This impeller 1 has a plurality of blades 2 having a thin wing on an outer periphery of a hub 3 at a constant thickness. The blower impeller is constituted such that a front edge 6 of the impeller 2 becomes a convex curved line making a center point of the front edge 6 as a peak against a windward side on the rotation track figure of these blades 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blower impeller used for a mixed flow blower or an axial flow blower used for an air conditioner or other equipment.

[0002]

2. Description of the Related Art A conventional thin-wing mixed flow blower is disclosed in
As shown in JP-A-294389, the impeller 21 has a substantially frustoconical hub 23 as shown in FIGS.
A plurality of thin blades 22 having a fixed thickness are provided integrally on the outer periphery of the blade. 7, the leading edge 26 is defined by the midpoint of the dash-dot line D-D connecting the midpoint of the leading edge 26 and the midpoint of the trailing edge 27 on the rotation locus diagram shown in FIG. 7. The outer periphery 28 side is a concave curve 26a with respect to the windward side from the vicinity.
In addition, the hub 23 side from the vicinity of the middle point is formed as a convex curve 26b. Further, the blade 22 has a trailing edge 27 formed linearly from the hub 23 side to the outer periphery 28 side on the rotation locus diagram.

[0003]

However, in the above-described conventional configuration, the outer periphery 2 is located near the middle point of the front edge 26 of the blade 22.
9 is a radial cross section of the blade 22 (a cross section taken along line E-E in FIG. 8), the outer side of the blade 22 is closer to the midpoint than in the vicinity of the midpoint. 28 side is a concave curve 29a with respect to the main airflow direction indicated by the arrow.
Had become.

The main flow of the suction flow of the impeller 21 of the mixed flow blower is the axial flow of the impeller 21.
The radial flow S flowing from the outer periphery 28 also exists in a certain amount. With respect to this radial flow S, the concave curve 29a, which is the portion of the blade element that occupies about half of the blade 22, has a shape that protrudes in the opposite direction to the radial flow S. The radial flow S is obstructed and obstructed. In other words, the concave curve 29a, which is a portion of the blade element occupying about half of the blade 22, has a convex shape with respect to the radial flow S from the outer periphery 28 which exists in a certain amount in the suction flow of the impeller 21. However, this does not impede or induce the radial flow S. As a result, since the radial flow S is not attracted, the blade elements near the hub 23 hardly contribute to aerodynamic work, and the entire blade 21 cannot perform sufficient aerodynamic work. For this reason, the static pressure efficiency of the impeller 21 is limited, and is not always high. This is nothing but the impeller of the prior art that is required to increase the static pressure efficiency by attracting the radial flow S and performing sufficient aerodynamic work.

[0005] The present invention is a blower impeller that solves the above-mentioned problems of the prior art, and its main object is to improve the static pressure efficiency.

[0006]

In order to solve the above-mentioned problems, the present invention comprises a plurality of thin blades having a constant thickness on the outer periphery of a hub. The leading edge is a blower impeller constituted by a convex curve having a peak near the midpoint of the leading edge with respect to the windward side.

By the above means, the blades near the hub also perform sufficient aerodynamic work for both the axial flow and the radial flow, which are the two suction flows of the impeller, so that the entire blade has sufficient aerodynamics. It can do the job and increase the static pressure efficiency of the blower.

[0008]

DETAILED DESCRIPTION OF THE INVENTION The invention according to claim 1 of the present invention has a plurality of thin blades having a fixed thickness on the outer periphery of a hub. The edge is a blower impeller constituted by a convex curve having a peak near the midpoint of the front edge with respect to the windward side.

In the above-described embodiment, the radial cross section of the blade is a convex curve with respect to the main airflow direction of the suction flow. Since it is concave with respect to the radial flow, it has a shape that rather induces the radial flow without hindering the radial flow. Therefore, for both the axial flow and the radial flow, which are the two suction flows of the impeller, the blade elements near the hub also perform sufficient aerodynamic work, and the entire blade performs sufficient aerodynamic work. It becomes possible.

[0010] The invention described in claim 2 is the same as the claim 1.
In the description, the blade is configured such that the trailing edge of the blade is a convex curve toward the windward side from the vicinity of the midpoint of the trailing edge toward the hub side, and the outer peripheral side from the vicinity of the midpoint is a substantially curved line that is linear. It is.

In the above embodiment, the increase in the blade area near the hub due to the convex curve at the leading edge of the blade is determined by the convex curve protruding from the vicinity of the midpoint of the trailing edge toward the windward side of the hub. It is possible to positively reduce the blade area near the hub and reduce the frictional resistance of the blade.

Further, the invention described in claim 3 is the first invention.
Alternatively, in the second aspect, the blade is a thick blade and has a ratio t / c of a maximum thickness t of the blade and a chord length c in a cross-sectional development on a flow path center line connecting a middle point of a leading edge and a middle point of a trailing edge. To 5
It is set in the range of 12%, the maximum thickness t is constant over the radial direction of the blade, the leading edge of the blade is arc-shaped, and the trailing edge of the blade is a pointed airfoil shape. .

In the above embodiment, the blade is provided with a thick blade having an airfoil shape having a constant maximum blade thickness in the radial direction of the blade as compared with a thin blade having a constant thickness. Therefore, the strength of the root of the blade is sufficiently maintained, and flow separation is prevented by adopting a thick wing airfoil shape.

The invention described in claim 4 is the first invention.
An air conditioner in which the blower having the blower impeller according to any one of claims to 3 is provided in an outdoor unit having a heat exchanger or the like.

In the above-described embodiment, the blower that performs the blowing action by the outdoor unit operates with high static pressure efficiency, so that the motor input is reduced and the aerodynamic work is performed with low noise.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

(Embodiment 1) FIGS. 1 to 4 show an embodiment corresponding to the invention described in claim 1 of the present invention. FIG. 1 is a schematic diagram showing an operating state of an impeller in a mixed flow blower. 2 is a plan view of the mixed flow blower impeller, FIG. 3 is a rotation locus diagram of the mixed flow blower impeller, and FIG. 4 is a radial cross-sectional view of the mixed flow blower impeller (a cross-sectional view taken along line AA in FIG. 2). is there.

Reference numeral 1 denotes an impeller of a mixed flow blower, in which three blades 2 of thin blades having a constant thickness are integrally provided at regular intervals on an outer peripheral surface of a hub 3 having a substantially truncated cone shape. And this impeller 1
The hub 3 is fixed to a rotating shaft of a motor 4, housed in an appropriate casing 5, and rotated by the motor 4 to perform a blowing operation as a suction flow. As shown by the arrow in FIG. 1, most of the air flows in from the front edge 6 of the blade 2 and flows out from the rear edge 7 to perform aerodynamic work by the rotation of the impeller 2. Of the airflow and the suction flow,
The radial flow R flowing from the outer periphery 8 also exists in a certain amount.

As shown in FIG. 3, the blade 2 has a single-dot chain line BB (flow path center line BB) connecting the middle point of the leading edge 6 and the middle point of the trailing edge 7 of the blade 2 on the rotation locus diagram. B), and the leading edge 6 is configured as a convex curve with respect to the windward side with the vicinity as a peak,
The trailing edge 7 is constituted by a straight line.

In the above embodiment, as shown in FIG. 4, which is a sectional view in the radial direction (a sectional view taken along the line AA in FIG. 2 which is a plan view of the mixed flow blower), the blade 2 has the main flow direction of the suction flow. On the other hand, the front side is a convex curve, but the radial side flow R from the outer periphery 8 existing in a certain amount in the suction flow of the impeller 1 results in a concave curve on the rear side. In addition, the blade has a vane shape that does not obstruct the radial flow but rather induces it. Therefore, the axial flow (main airflow) which is two of the suction flows of the impeller 1
The blades near the hub 3 also perform sufficient aerodynamic work for both the radial flow R and the radial flow R, so that the entire blade 2 performs almost completely aerodynamic work, and as a result, the static pressure efficiency of the blower is reduced. It can be higher.

The specific effect is that, when an experiment is carried out with a mixed flow blower having an outer diameter of 415 mm, the maximum static pressure efficiency is about 4%.
% Static pressure efficiency was found to be improved.

(Embodiment 2) FIG. 5 is a rotation locus diagram of a mixed flow blower according to an embodiment corresponding to the second aspect of the present invention. The invention of the second embodiment differs from the mixed flow blower of the first embodiment in that the curved shape of the trailing edge 7 is specified.
Since the other configuration and operation and effect are the same, the same reference numerals are given to such portions, detailed description is omitted, and only different points will be mainly described.

As shown in FIG. 5, the blade 2 has a single-dot chain line CC (flow path center line CC) connecting the middle point of the leading edge 6 and the middle point of the trailing edge 7 of the blade 2 on the rotation locus diagram. The front edge 6 is configured to have a convex curve with respect to the windward side so as to have a peak around the vicinity thereof, and the rear edge 7 has a C-line around the flow path center line CC.
The hub 3 side from the vicinity of C is formed into a convex curve 7b with respect to the windward side, and the outer periphery 8 side from the vicinity of C-C is formed into a straight line 7a as a whole and substantially curved.

In the above embodiment, since the vicinity of the midpoint of the leading edge 6 of the blade 2 on the rotation locus diagram of the blade 2 is peaked and formed into a convex curve with respect to the windward side, aerodynamic work is not performed much. The wing area in the vicinity of the hub 3 which is not used increases. However, on the other hand, the trailing edge 7 of the blade 2 is formed as a convex curve 7b on the hub 3 side from the vicinity of the middle point of the trailing edge 7 toward the windward side, and is formed as a straight line 7a on the outer periphery 8 side from the vicinity of the middle point. As
The trailing edge 7 of the substantially curved line is formed, and the hub 3 side is projected from the vicinity of the midpoint of the trailing edge 7 of the blade 2 to the windward side. Further, even in the plan view of the mixed flow blower, the blade area near the hub 3 is reduced. Therefore, the blade area near the hub 3 of the blade 2 can be reduced, so that the blade area near the hub 3 that does not significantly contribute to the aerodynamic work of the mixed flow blower is reduced, thereby reducing the frictional resistance of the blade.
Fluid noise can be reduced.

The specific effect of reducing the fluid noise is as follows.
When an experiment was performed using a mixed flow blower having an outer diameter of 415 mm as an outdoor unit of an air conditioner having a heat exchanger, the operating load point of the outdoor unit of the air conditioner having a heat exchanger was about 1 dB.
The low noise effect of (A) was obtained. As described above, the present invention has an effect on both the improvement of the static pressure efficiency and the reduction of noise.

(Embodiment 3) FIG. 6 shows a flow channel center line BB (or a flow channel center line) of an impeller 1 of a mixed flow blower according to an embodiment corresponding to the third aspect of the present invention. C-
It is a sectional development view of C). The invention of the third embodiment is different from the first or second embodiment in which the ratio of the maximum thickness t of the blade 12 to the chord length C is set in a specific range, unlike the first or second embodiment having the blade having a constant thickness. Since the configuration and the operation and effect are the same, such portions are denoted by the same reference numerals, detailed description thereof will be omitted, and only different points will be mainly described.

The blade 12 is a thick wing and has a flow path center line BB (or CC) connecting the midpoint of the leading edge 6 and the midpoint of the trailing edge 7.
The ratio t / c of the maximum thickness t and the chord length c of the blade 12 in the above cross-section development is set in the range of 5 to 12%.
The maximum thickness t is constant over the radial direction of the
Has a circular arc shape 12a, and the trailing edge of the blade 12 has a pointed airfoil shape 12b.

In the above embodiment, compared to a thin blade having a constant thickness, the blade is provided with a thick blade having an airfoil shape whose maximum blade thickness t is constant in the radial direction of the blade 12, so that a chord is provided. The maximum blade thickness t is constant without increasing even on the outer peripheral side of the longer blade 12. For this reason, even when the mixed flow blower is manufactured by resin molding, the strength of the blade root is sufficiently maintained regardless of the construction method. And since the thick wing having the airfoil shape is used, separation of the flow from the blade 12 is prevented,
The fluid noise can be further reduced.

The specific effect of reducing the fluid noise is as follows. An experiment was conducted using a mixed flow blower having an outer diameter of 415 mm as an outdoor unit of an air conditioner having a heat exchanger. Approximately 2.5 dB at the operating load point of the outdoor unit
The low noise effect of (A) was obtained. As described above, the present invention has the effect of improving the static pressure efficiency and further reducing the noise.

In the third embodiment, the blade 12
Is a thick wing in which the ratio t / c of the maximum thickness t to the chord length c is in the range of 5 to 12% because the center of the flow path connecting the midpoint of the leading edge 6 and the midpoint of the trailing edge 7 This is a development view of a cross-section on line BB (or CC), and the development of a cross-section slightly shifted left and right from the middle point of the leading edge and the middle point of the trailing edge is substantially the same. The effect of is obtained.

(Embodiment 4) The invention of Embodiment 4 is described in claim 4.
The circuit configuration of a refrigeration cycle in which the blower impellers of the inventions described in the first to third embodiments (not shown) are connected to the outdoor unit and the indoor unit by pipes in an embodiment corresponding to the invention described in (1). It is used for an air blower circuit or the like of an outdoor unit having a heat exchanger in a separate type air conditioner configured by separating members.

According to the air conditioner having the above configuration, the outdoor unit can be operated with high static pressure efficiency by the blower that blows air to the heat exchanger of the outdoor unit, so that the motor input is reduced and the aerodynamic work is performed with low noise. Can be done.

[0033]

As is apparent from the above embodiment, the invention according to claim 1 of the present invention includes a motor and an impeller driven by the motor, and the impeller has a constant thickness on the outer periphery of the hub. The thin blade has a plurality of blades, on the rotation locus diagram of the blade, the leading edge of the blade is configured with a convex curve having a peak near the midpoint of the leading edge with respect to the windward side. For both the axial flow and the radial flow, which are the two suction flows of the impeller, the blade elements near the hub also perform aerodynamic work sufficiently, and the blade as a whole performs aerodynamic work to perform the static pressure of the blower. Efficiency can be increased.

According to a second aspect of the present invention, in the invention according to the first aspect, the blade is formed such that the trailing edge of the blade is a convex shape with respect to the windward side on the hub side from near the midpoint of the trailing edge. The outer peripheral side from the vicinity of the midpoint is configured as a substantially linear curve, and the convex curve of the leading edge of the blade increases the blade area near the hub rather than the convex shape of the trailing edge. The curve can positively reduce the blade area near the hub, reduce the frictional resistance of the blades, and reduce noise.

According to a third aspect of the present invention, in the invention according to the first or second aspect, the blade is a thick wing and has a flow path center connecting a middle point of the leading edge and a middle point of the trailing edge. Ratio t / c of maximum blade thickness t to chord length c in cross-section development on line
Is set in the range of 5 to 12%, the maximum thickness t is constant over the radial direction of the blade, the leading edge of the blade is arc-shaped, and the trailing edge of the blade is a pointed airfoil shape. Compared to a thin blade with a constant thickness, the blade has thicker blades with an airfoil shape with the maximum blade thickness constant in the radial direction of the blade, and the blade thickness from the outer periphery may increase. Since there is no blade, the strength of the root of the blade is sufficiently maintained, and the separation of the flow can be prevented by adopting the airfoil shape of the thick blade, so that the noise can be further reduced.

The invention described in claim 4 is the first invention.
An air conditioner provided with a blower having the blower impeller according to any one of claims 3 to an outdoor unit having a heat exchanger or the like, and the outdoor unit has a high static pressure efficiency by operating the blower. Therefore, the motor input can be reduced and aerodynamic work can be performed with low noise.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an operation state of an impeller of Embodiment 1 in a mixed flow blower of the present invention.

FIG. 2 is a plan view of an impeller of the mixed flow blower.

FIG. 3 is a rotation locus diagram of an impeller in the mixed flow blower.

FIG. 4 is an impeller in FIG. 2 of the impeller of the mixed flow fan;
Sectional view of -A line

FIG. 5 is a rotation locus diagram of the impeller of the second embodiment in the mixed flow blower.

FIG. 6 is an exploded cross-sectional view of the impeller of Embodiment 3 of the mixed flow blower, taken along a flow path center line BB (or CC).

FIG. 7 is a rotation locus diagram of an impeller in a conventional mixed flow blower.

FIG. 8 is a plan view of the impeller.

9 is a radial sectional view of the impeller (a sectional view taken along line EE in FIG. 8).

[Description of Signs] 1 Impeller 2, 12 Blade 3 Hub 6 Front edge 7 Trailing edge 7a Straight line 7b Convex curve 8 Outer circumference 12a Arc shape 12b Pointed airfoil shape

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H033 AA02 AA18 BB02 BB07 CC01 DD03 DD27 EE06 EE08 EE11 EE19 3L054 BA04 BB03

Claims (4)

[Claims] 1. A motor and an impeller driven by the motor, wherein the impeller has a plurality of thin-bladed blades having a constant thickness on the outer periphery of a hub. The blower impeller according to any one of claims 1 to 3, wherein a leading edge of the blade is a convex curve having a peak near a midpoint of the leading edge with respect to the windward side. 2. The trailing edge of the blade is formed to have a convex curve toward the windward side from the vicinity of the midpoint of the trailing edge toward the hub side, and a substantially curved line having a straight outer periphery from the vicinity of the midpoint. The blower impeller according to claim 1. 3. The blade has a ratio t / c between the maximum thickness t of the blade and the chord length c in a cross-sectional development on a flow path center line connecting the middle point of the leading edge and the middle point of the trailing edge of the thick blade. １２12%, and the maximum thickness t is constant over the radial direction of the blade, the leading edge of the blade is formed in an arc shape, and the trailing edge of the blade is formed in a pointed airfoil shape. The blower impeller according to claim 1 or 2. 4. An air conditioner wherein the blower having the blower impeller according to any one of claims 1 to 3 is provided in an outdoor unit having a heat exchanger or the like.