JP5263198B2 - Impeller, blower and air conditioner using the same - Google Patents

Abstract

The invention relates to an impeller and a pressure fan and an air conditioner using the same. In a pressure fan having an axial flow impellor or a ramp-flow impeller, the flow is inhibited from approaching to the periphery of the blade, and the enhancement of friction loss at the periphery, the loss due to the change of blade tip eddy and blade tail eddy are reduced, and the input of a motor is inhibited to be quite low. The impeller is composed by a wheel hub disposed at the rotating center and a plurality of blades disposed at the periphery of the wheel hub. The cross section in the radius direction of the blades is in the shape of a concave curve at the peripheral side with respect to a suction side, and is in the shape of a convex curve at the wheel hub side with respect to the suction side. The convex curve is approximately in the shape of a circular arc and extends from the front edge side to the rear edge of the blade. The value of radius of curvature of the convex curve is reduced.

Description

  The present invention relates to a blower provided with an impeller such as an axial flow or a mixed flow used in an outdoor unit such as an air conditioner.

  In recent years, in air conditioners, energy conservation has been rapidly progressing as a countermeasure against global warming and the like, and lower input of devices has been promoted. On the other hand, improvement of heat exchange performance of indoor units and outdoor units such as improvement of heating comfort is required, and high efficiency and high performance of indoor and outdoor blowers are indispensable together with improvement in performance of heat exchangers. Conventionally, axial blowers or mixed flow blowers have been used as blowers for outdoor units from the viewpoint of large air volume and low noise. However, in order to promote further energy saving of the air conditioner, it is necessary to reduce the input of the blower of the outdoor unit, and it is required to further improve the blowing efficiency of the blower while maintaining a predetermined air volume as the outdoor unit. ing.

  11 to 13 show a propeller fan mounted on a conventional outdoor unit for an air conditioner (see, for example, Patent Document 1). 11 and 12, reference numeral 101 denotes a propeller fan, and a hub 102 attached to the fan rotation shaft A is provided with two blades 103 having the same shape, and the blades 103 correspond to an air flow outflow portion during fan rotation. The blade trailing edge 103a is provided with a substantially arc-shaped, V-shaped, or polygonal trailing edge recess 103b that is recessed in the direction opposite to the air flow. One blade 103 is arranged in a state of being inverted with respect to the other blade 103 in a range of 180 ° ± 5 ° around the fan rotation axis A. For example, the one blade 103 and the other blade 103 are arranged symmetrically with respect to the fan rotation axis A. An orifice ring 104 is provided around the discharge side of the propeller fan 101 with a predetermined clearance from the blades 103.

  In FIG. 13, the outdoor unit 111 includes an outdoor air blower comprising a planar L-shaped outdoor heat exchanger 113, the propeller fan 101, the orifice ring 104, and the fan motor 114. The circuit 115, the compressor 116, a four-way valve, an inverter, etc. (not shown) are accommodated. The outdoor blower circuit 115 and the compressor 116 are partitioned by a partition plate 117.

  Next, the operation of the propeller fan described in Patent Document 1 and the outdoor unit for an air conditioner will be described. First, the propeller fan 101 is rotationally driven by the fan motor 114 via the rotation axis A, and the outdoor air is guided into the propeller fan 101 via the outdoor heat exchanger 113. At that time, dynamic pressure and static pressure are applied by the wing 103 and the orifice ring 104 provided around the wing 103 to perform a blowing action. Further, when passing through the outdoor heat exchanger 113, the compressor 116 operates to exchange heat with the refrigerant flowing in the pipe of the outdoor heat exchanger 113.

  Here, the blade 103 is provided with a substantially arc-shaped, V-shaped, or polygonal trailing edge recessed portion 103b that is recessed in a direction opposite to the air flow at the blade trailing edge portion 103a corresponding to the outflow portion of the air flow during fan rotation. Thus, the area of the blade 103 can be reduced without complicating the shape of the blade trailing edge 103a, and the blade wake vortex, that is, the flow of airflow along the pressure surface and suction surface of the blade The vortex generated by the collision at the downstream portion of 103a is suppressed to be small, and the increase of the flow loss is suppressed. Thereby, when the rotation speed of the propeller fan 101 is increased to increase the air volume, the load applied to the fan motor 114 can be suppressed to be small, and energy saving can be improved.

14 to 16 show other conventional blower impellers for air conditioners (see, for example, Patent Document 2). As shown in FIGS. 14 and 15, the air-conditioning fan impeller 151 fixes the shaft of the motor 150 to the center of the rotation shaft, and radiates the thin blades 152 around the hub 153 having a substantially frustoconical section. Three are provided. Then, as shown in FIG. 14, the shaft of the motor 150 is fixed to the center of the rotation axis of the hub 153 of the air-conditioning fan impeller 151, and is placed in an appropriate casing 159 that follows the rotation locus of the outer peripheral edge of the blade 152. ing.

  Here, as shown in FIGS. 16 (a), 16 (b) and 16 (c), the radial cross-sectional shape of the blade 152 is concave with respect to the windward side on the outer peripheral end 6 side near the middle dotted line EE. From the vicinity of the middle dotted line EE, the hub 153 side is configured by a convex curve with respect to the windward side. Further, 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 middle dotted line EE is a radial cross section on the leading edge 154 side of the wing 152, and the radius near the center of the chord length of the wing 152. The value is increased in the order of the directional cross section and the radial cross section near the trailing edge 155 of the wing 152. That is, the radius of curvature of the radial cross section on the leading edge 154 side of the blade 152 is r1, the radius of curvature of the radial cross section near the center of the chord length of the blade 152 is r2, and the radial cross section near the trailing edge 155 of the blade 152. When the radius of curvature of the portion is r3, the relationship of the magnitude of the radius of curvature is r1 <r2 <r3.

  Next, the operation of the blower impeller for an air conditioner described in Patent Document 1 will be described. The air blower impeller 151 for air conditioning is rotated by the motor 150 to produce the air blowing action. At that time, dynamic pressure and static pressure are added by the blades 152 and the orifice ring 159 provided around the blades 152 to perform the air blowing action. Make it. With the above-described configuration, a leakage flow is generated from the pressure surface 158 of the blade 152 on the leeward side toward the negative pressure surface 157 on the windward side and passing between the blade outer peripheral end 156 and the casing 159. As a result, the generation of the blade tip vortex generated on the suction surface 157 near the outer periphery of the blade 152 is promoted by the concave curved portion of the blade 2 itself, thereby reducing noise.

  Further, the blade tip vortex is generated on the suction surface 157 of the blade, and tends to peel from the suction surface 157 of the blade 152 at a position near the trailing edge 155 from near the center of the chord length of the blade 152. However, the curved radius of curvature of the concave shape is such that the radial cross section on the leading edge 154 side of the wing 152, the radial cross section near the center of the chord length of the wing 152, and the radial cross section near the trailing edge 155 of the wing 152. Since the radius of curvature r3 on the radial cross section near the trailing edge 155 of the blade 152 is sufficiently large so that the value increases in order of the portion, the concave portion near the trailing edge has the tip vortex. The peeling phenomenon is not hindered. Therefore, the loss due to vortex separation is reduced and the efficiency can be further improved.

Japanese Patent Laid-Open No. 2005-140081 JP 2003-148395 A

  However, in the conventional configuration as described above, the chord length is longer at the outer peripheral side of the blades 103 and 152 or near the outer ends 103d and 156 than the hub side 103c and the vicinity of the center in the radial direction. Since the vortex is attracted, the ratio of the work amount as the wing increases, and the flow from the front edge 103b, 154 side of the wing is offset. Therefore, an increase in friction loss cannot be suppressed even on the pressure surfaces 103P and 158 and the suction surfaces 103S and 158 of the blade. Further, in the vicinity of the outer peripheral end, the propeller fan described in Patent Document 1 has a long chord length, so there is a limit to keep the wake vortex small.

Furthermore, since the blower described in Patent Documents 1 and 2 is surrounded by the orifice rings 104 and 159 only around the discharge side of the propeller fan 101 and the blower impeller 151, the blade 10
3 and 152, airflow flows from the outer periphery of the suction side. At this time, as shown in FIGS. 13 and 14, the suction side of the orifice ring has a shape having end portions 104a and 159a. Therefore, the flow is separated in the vicinity of the end portions 104a and 159a, and the turbulent flow is caused by the blades 103 and 152. From the outer periphery on the suction side of the blade, and the blade tip vortex of the suction surface 103S, 158 near the outer periphery side of the blades 103, 152 or the outer periphery ends 103d, 156 is disturbed near the trailing edges 103a, 155. The loss due to fluctuation of vortex cannot be suppressed. In addition, the wake vortex is also disturbed, and it is difficult to suppress the loss due to fluctuations in the wing vortex. In addition, it is difficult to suppress an increase in blowing noise caused by fluctuations in the blade tip vortex and the wake vortex.

  The present invention solves the above-mentioned conventional problems, and in a blower having an axial flow type or mixed flow type impeller used for blowing an outdoor unit of an air conditioner, the flow is shifted to the outer peripheral side of the blade. In addition to suppressing an increase in friction loss on the blade pressure surface and suction surface, and using an orifice ring that surrounds the blade discharge side outer periphery, the turbulence of the inflow air flow from the blade suction side outer periphery is suppressed. A fan that suppresses the loss associated with fluctuations in the blade tip vortex and wake vortex of the blade, reduces input to the blower, and suppresses increase in blowing noise due to fluctuations in the blade vortex and wake vortex. It aims at providing the air conditioner which suppressed the reduction | decrease in the input of an apparatus, and the increase in the outdoor ventilation noise, ensuring the ventilation volume for implement | achieving the used predetermined heat exchange capability.

  In order to solve the above-described conventional problems, an impeller according to the present invention includes a hub provided at the center of rotation and a plurality of blades provided around the hub, and a radial cross-sectional shape of the blade is an outer peripheral side. Is a concave curve with respect to the suction side, a convex curve is formed with respect to the suction side on the hub side, and the convex curve on the hub side is substantially arc-shaped and is approximately as it goes from the front edge side to the rear edge side of the blade. The value of the radius of curvature of the arc-shaped convex curve is small.

  With this configuration, the radius of curvature of the convex curve decreases from the leading edge on the hub side of the blade toward the trailing edge, so that the dent formed on the pressure surface side of the convex portion extends from the leading edge of the blade to the trailing edge. It gradually becomes narrower. For this reason, the airflow flowing into the pressure surface side of the convex portion on the hub side has a larger radial component toward the trailing edge due to the centrifugal force applied from the blade to the airflow, but is guided to the recess formed on the pressure surface side. Blow out from the trailing edge to the discharge side of the impeller.

  In addition, the airflow that flows into the suction side of the convex part on the hub side also flows in the circumferential direction along the convex part as the convex shape goes to the trailing edge side on the inner peripheral side from the convex part apex. Blow out from the trailing edge to the discharge side of the impeller.

  For this reason, between the blades formed by the plurality of blades of the impeller, the hub-side flow is prevented from being displaced toward the outer peripheral side by the centrifugal force applied to the airflow, and blown out from the trailing edge side of the hub-side blades. And the chord length is longer than the hub side, and by guiding the tip vortex to the suction surface side of the recess on the outer peripheral side, the flow from the hub side is moved to the outer peripheral side even if the flow on the outer peripheral side is promoted. The flow velocity of the airflow on the outer peripheral side does not increase without deviation, and the increase in friction loss on the pressure surface and the negative pressure surface on the outer peripheral side of the blade is suppressed.

  The impeller of the present invention promotes the generation of blade tip vortices on the outer peripheral side and suppresses disturbance of the flow on the outer periphery of the blades due to the collapse of the blade tip vortex, while the flow on the hub side is affected by the centrifugal force applied to the airflow. It is suppressed from being displaced to the side and blown out from the trailing edge side of the blade. As a result, the blade outer chord has a long chord length, and the tip vortex is guided to the suction side of the outer recess, so that the flow from the hub side can be Accordingly, the flow velocity of the airflow on the outer peripheral side does not increase and the increase in friction loss on the pressure surface and the negative pressure surface on the outer peripheral side of the blade is suppressed.

Therefore, an increase in the blowing noise of the blower equipped with such an impeller is suppressed, the aerodynamic efficiency of the blower is improved, and the input of the blower motor can be reduced. Furthermore, an air conditioner equipped with such a blower can suppress a reduction in device input and an increase in outdoor blowing noise while ensuring a blown amount for realizing a predetermined heat exchange capability.

Meridian cross-sectional view of a blower having a partial rotation locus in Embodiment 1 of the present invention A meridional section showing the rotation trajectory of the impeller in the first embodiment Front view of impeller in embodiment 1 (A) AO (front edge side radial direction of the impeller) cross-sectional view of FIG. 3 (b) B-O (radial direction near the center of the chord length of the impeller blade) of FIG. 3 (c) ) Cross-sectional view taken along the line C-O (in the radial direction of the trailing edge of the impeller) in FIG. Sectional drawing of the outdoor unit of the air conditioner in Embodiment 1 The characteristic diagram which shows the relationship between the ratio of the impeller outer diameter of the diameter of the cylindrical hub in the same Embodiment 1, and the input of the motor of a fan on the conditions which ensured predetermined aerodynamic characteristics (air volume, static pressure) The meridional section showing the rotation trajectory of another impeller in the first embodiment Front view of another impeller in the first embodiment Meridian cross-sectional view of a blower having a partial rotation trajectory in Embodiment 2 of the present invention The ratio of the distance S between the first orifice ring and the second orifice ring in the second embodiment in the radial direction and the impeller outer diameter D2 and the condition of the fan that ensures predetermined aerodynamic characteristics (air volume, static pressure) are ensured. Characteristic diagram showing the relationship of motor input Front view of conventional impeller A perspective view of a conventional impeller Sectional view of an outdoor unit of a conventional air conditioner A meridional section of another conventional blower with partial rotation trajectory Front view of another conventional blower (A) AO (front edge side radial direction of the impeller) cross-sectional view of FIG. 15 (b) B-O (radial direction near the center of the chord length of the impeller blade) of FIG. 15 (c) FIG. 15 is a cross-sectional view taken along the line C-O in FIG.

  The invention according to claim 1 is an impeller comprising a hub provided at the center of rotation and a plurality of blades provided around the hub, and the radial cross-sectional shape of the blade is on the suction side on the outer peripheral side. On the hub side, it is a convex curve with respect to the suction side, and the convex curve on the hub side is substantially arc-shaped, and the convex shape is substantially arc-shaped as it goes from the front edge side to the rear edge side of the blade. The value of the radius of curvature of the shape curve is small.

  By adopting such a configuration, the curvature radius of the convex curve decreases from the front edge on the hub side of the blade toward the rear edge side, so that the depression formed on the pressure surface side of the convex portion is from the front edge of the blade. Gradually narrow toward the trailing edge. For this reason, the airflow flowing into the pressure surface side of the convex portion on the hub side has a larger radial component toward the trailing edge due to the centrifugal force applied from the blade to the airflow, but is guided to the recess formed on the pressure surface side. Blow out from the trailing edge to the discharge side of the impeller.

  Also, the airflow that flows into the suction side of the convex part on the hub side also becomes steep as the convex shape slopes toward the rear edge side on the inner peripheral side from the convex part apex, so the flow toward the outer peripheral side follows the convex part It flows in the circumferential direction and blows out from the trailing edge to the discharge side of the impeller.

  For this reason, between the blades formed by the plurality of blades of the impeller, the hub-side flow is prevented from being displaced toward the outer peripheral side by the centrifugal force applied to the airflow, and blown out from the trailing edge side of the hub-side blades.

  As a result, the chord length on the outer circumference side is longer than that on the hub side, promoting the generation of wing tip vortices and suppressing turbulence in the outer circumference of the blade due to the collapse of the wing tip vortex, while reducing the chord length on the outer circumference side. By guiding the blade tip vortex to the suction surface side of the concave part on the outer peripheral side, the flow from the hub side does not shift to the outer peripheral side and the air flow velocity on the outer peripheral side is increased by guiding the blade tip vortex to the suction side. First, it suppresses an increase in friction loss on the pressure surface and the suction surface on the outer peripheral side of the blade.

  According to a second aspect of the present invention, the hub has a substantially cylindrical shape in which the inner diameter of the front edge of the blade and the inner diameter of the rear edge are substantially the same.

  By adopting such a configuration, the airflow that flows into the pressure side and suction side of the convex shape on the hub side flows in the circumferential direction without being obstructed by the inclined flow-type hub, so the flow loss also increases on the hub side. Can be kept small, and the loss generated by the impeller can be further reduced.

  According to a third aspect of the present invention, when the diameter of the substantially cylindrical hub is D1 and the outer diameter of the impeller is D2, D1 / D2 is 0.135 to 0.368.

  By adopting such a configuration, by optimizing the diameter of the cylindrical hub, the pressure side and the negative pressure side of the convex shape of the hub side are obtained under the conditions that ensure the predetermined aerodynamic characteristics (air volume, static pressure). Both airflows flowing into the circumferential direction flow in the circumferential direction, and the effect of suppressing flow loss on the hub side is maximized.In addition, the chord length is longer than that on the hub side, and the tip vortex is negative in the recesses on the outer circumferential side. Even if the flow on the outer peripheral side is promoted by guiding it to the pressure side, the flow from the hub side does not shift to the outer peripheral side, the flow velocity of the outer peripheral side is kept low, and the friction on the pressure surface and the suction surface on the outer peripheral side of the blade The effect of suppressing the increase in loss can be maximized.

  According to a fourth aspect of the present invention, there is provided a blower comprising a motor, the impeller according to any one of the first to third aspects, and an orifice ring surrounding the discharge side of the impeller.

  With such a configuration, the flow loss on the hub side is suppressed, the chord length is long, and the vortex tip vortex is guided to the suction surface side of the concave portion on the outer peripheral side to promote the flow on the outer peripheral side, The flow rate of the airflow on the outer peripheral side is kept low, the increase in friction loss on the pressure surface and the negative pressure surface on the outer peripheral side of the blade is suppressed, the increase in blowing noise of the blower equipped with such an impeller is suppressed, and the aerodynamic efficiency of the blower is reduced. Thus, the input of the motor for the blower can be reduced.

  According to a fifth aspect of the present invention, there is provided a substantially cylindrical first orifice ring in which the orifice ring surrounds the discharge-side outer periphery of the impeller and the discharge-side tip is an open end; and the first orifice ring A second orifice ring that is substantially concentrically provided on the outside and has a higher axial height than the first orifice ring, and a curve that smoothly connects the suction side of the first orifice ring and the suction side of the second orifice ring The blower according to claim 4, comprising a portion.

  With this configuration, since the suction side of the second orifice ring and the first orifice ring are connected by a smooth curved portion and there is no end on the suction side, when the airflow flows from the outer periphery of the blade not surrounded by the orifice ring, There is no smooth flow and flows between the wings. Further, on the outer peripheral side of the blade or in the vicinity of the outer peripheral end, the loss due to the fluctuation of the blade tip vortex can be suppressed without disturbing the blade tip vortex on the suction surface in the vicinity of the trailing edge. In addition, the loss due to fluctuations in the wake vortex is kept small.

As a result, in a blower having an axial flow type or mixed flow type impeller, the flow is shifted to the outer peripheral side of the blade, suppressing an increase in friction loss on the pressure surface and the negative pressure surface of the blade, and also on the discharge side of the blade When using an orifice ring that surrounds the outer periphery, the turbulence of the inflow airflow from the outer periphery of the blade suction side is suppressed, and the loss associated with fluctuations in the blade tip vortex and the blade wake vortex on the blade outer periphery is suppressed to a small level. The efficiency can be further improved, the input to the blower motor can be kept low, and an increase in blowing noise due to fluctuations in the blade tip vortex and wake vortex can be suppressed.

  According to the sixth aspect of the present invention, when the radial distance between the first orifice ring and the second orifice ring is S and the outer diameter of the impeller is D2, S / D2 is 0.020-0. .092.

  By adopting such a configuration, by optimizing the radial interval between the first orifice ring and the second orifice ring, the orifice ring can be used under the condition that a predetermined aerodynamic characteristic (air volume, static pressure) is secured. When the airflow flows from the outer periphery of the blade that is not surrounded, the flow between the blades becomes a smooth flow with minimal separation. In addition, on the outer peripheral side of the blade or in the vicinity of the outer peripheral end, the effect of suppressing the blade tip vortex fluctuation near the trailing edge of the suction surface is maximized, and the loss due to the blade tip vortex fluctuation is minimized. It also minimizes losses due to fluctuations in the wake vortex.

  The invention according to claim 7 is a finned tube type heat exchanger for exchanging heat between air and refrigerant, the impeller according to any one of claims 1 to 3, or any one of claims 4 to 6. An air conditioner comprising: the blower according to claim 1; and a box housing the heat exchanger and the blower.

  With this configuration, the impeller according to any one of claims 1 to 6 or an increase in the blowing noise of the blower is suppressed, the aerodynamic efficiency of the blower is improved, and the input of the fan motor is reduced. An air conditioner equipped with such an air blower can suppress a reduction in input of the device and an increase in outdoor air blowing noise while securing an air blowing amount for realizing a predetermined heat exchange capability.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a meridional sectional view of a blower having a partial rotation locus according to Embodiment 1 of the present invention. FIG. 2 is a meridional sectional view showing a rotation locus of the impeller according to the first embodiment. FIG. 3 is a front view of the impeller according to the first embodiment. 4A is a cross-sectional view taken along the line AO in FIG. 3 (cross-sectional view in the radial direction of the leading edge side of the impeller), and FIG. 4B is a cross-sectional view taken along the line B-O in FIG. (C) is a cross-sectional view taken along the line C-O of FIG. 3 (a radial direction cross-sectional view of the trailing edge of the impeller). FIG. 5 is a cross-sectional view of the outdoor unit of the air conditioner according to the first embodiment. FIG. 6 is a diagram showing the relationship between the ratio of the impeller outer diameter to the diameter of the cylindrical hub in the first embodiment and the input of the motor of the blower under conditions that ensure predetermined aerodynamic characteristics (air volume, static pressure). . FIG. 7 is a meridional sectional view showing a rotation locus of another impeller according to the first embodiment. FIG. 8 is a front view of another impeller according to the first embodiment.

  First, as shown in FIG. 1, the blower 1 includes an impeller 2, a motor 3, and a bell mouth-shaped orifice ring 4 surrounding the periphery of the discharge side of the impeller 2. The bell mouth shaped orifice ring has an end 4a on the suction side.

  As shown in FIGS. 2 and 3, the impeller 2 includes a cylindrical hub 5 connected to the rotation shaft 3 a of the motor 3 and two blades 6 disposed around the hub 5. . As shown in FIG. 3, the outer peripheral side 6 a of the blade 6 is inclined forward in the rotational direction of the impeller 2 with respect to the hub side 6 b.

Further, as shown in FIGS. 4A, 4B, and 4C, the blade 6 has a radial cross-sectional shape that is concave from the vicinity of the radial center of the blade 6 on the outer peripheral side 6a with respect to the suction side. The hub 6b side from the vicinity of the center of the blade 6 in the radial direction is a convex curve with respect to the suction side.

  Further, from the vicinity of the radial center of the blade 6 on the hub side 6b, the radius of curvature of the curve that is convex with respect to the suction side is the radial cross section on the leading edge 7 side of the blade 6, the chord length of the blade The radial section in the vicinity of the center of the blade and the radial section in the vicinity of the trailing edge 8 of the blade are arranged so that the values become smaller. That is, the radius of curvature of the radial cross section on the front edge 7 side of the blade 6 is R1, the radius of curvature of the radial cross section near the center of the chord length of the blade 6 is R2, and the radial cross section near the rear edge 8 of the blade 6 When the radius of curvature of the part is R3, the relationship of the magnitude of the radius of curvature is R1> R2> R3.

  About the air blower 1 comprised as mentioned above, the operation | movement is demonstrated below. First, the impeller 2 is rotated by the motor 3 via the rotating shaft 3a. At that time, dynamic pressure and static pressure are applied by the blade 6 and the orifice ring 4 provided around the discharge side of the blade 6. Makes air blowing.

  Here, as shown in FIG. 4, the radial cross section of the blade 6 has a concave curve with respect to the suction side on the outer peripheral side 6a, and a convex curve with respect to the suction side on the hub side 6b. The convex curve on the side 6b is substantially arc-shaped, and the value of the radius of curvature of the substantially arc-shaped convex curve decreases from the front edge 7 side to the rear edge 8 side of the blade, so that a convex hub The dent 11 formed on the pressure surface 9 side of the side 6b gradually narrows from the front edge 7 to the rear edge 8 of the blade 6. For this reason, the airflow flowing into the pressure surface 9 side of the convex portion of the hub side 6b has a larger radial component toward the trailing edge 8 due to the centrifugal force applied from the blade 6 to the airflow, but is formed on the pressure surface 9 side. It is guided to the recess 11 and blows out from the rear edge 8 of the blade 6 to the discharge side of the impeller 2.

  Further, the airflow that flows into the negative pressure surface 10 side of the convex hub side 6b also becomes steeper as the convex inclination toward the trailing edge 8 side on the inner peripheral side 6b ′ from the apex of the convex shape. To the discharge side of the impeller 2 from the trailing edge 8 flows in the circumferential direction along the convex portion.

  For this reason, it is suppressed that the flow on the hub side 6b is shifted to the outer peripheral side 6a by the centrifugal force applied to the airflow between the blades formed by the two blades 6 of the impeller 2, and the rear side of the blade 6 on the hub side 6b. It blows out from the edge 8 side.

  As a result, the outer peripheral side 6a of the blade 6 has a longer chord length than the hub side 6b, promotes the generation of the blade tip vortex and suppresses the disturbance of the flow on the outer peripheral side 6a of the blade 6 due to the collapse of the blade tip vortex. By guiding the blade tip vortex to the negative pressure surface 10 side of the concave outer peripheral side 6a, the flow from the hub side 6b is not offset toward the outer peripheral side 6a even if the flow on the outer peripheral side 6a is promoted. The flow velocity is not increased, and an increase in friction loss on the pressure surface 9 and the suction surface 10 on the outer peripheral side 6a of the blade 6 is suppressed.

  Further, as shown in FIGS. 2 and 3, the hub 5 of the impeller 2 is formed into a substantially cylindrical shape in which the inner diameter of the front edge 7 of the blade 6 and the inner diameter of the rear edge 8 are substantially the same diameter. Since the airflow flowing into the pressure surface 9 side and the negative pressure surface 10 side of the hub side 6b flows in the circumferential direction without being disturbed as compared to the inclined flow type hub, both of the hub side 6b can suppress an increase in flow loss. The loss generated in the impeller 2 can be further reduced as compared with a mixed flow type hub.

  Further, when the outer diameter D1 of the cylindrical hub 5 is set to D2 and the outer diameter of the impeller 2 is set to D2, D1 / D2 is set to 0.135 to 0.368, so that the cylindrical type shown in FIG. Characteristics of the relationship between the ratio D1 / D2 of the impeller outer diameter D2 of the hub diameter D1 and the ratio of the input of the motor 3 of the blower 1 to the conventional blower under the condition that predetermined aerodynamic characteristics (air volume, static pressure) are ensured. As shown in the figure, it is possible to realize a tendency to reduce the input to the conventional blower to 1 or less.

As shown in FIG. 5, the outdoor unit of the separate type air conditioner 15 includes a fin tube type heat exchanger 12 that performs heat exchange between air and refrigerant, an impeller 2, a motor 3, an orifice ring. 4 and the heat exchanger 12, the blower 1, and the box 14 that houses the compressor 13, the increase in blowing noise of the blower 1 is suppressed, and the aerodynamic efficiency of the blower 1 is improved. The input of the motor 3 for the blower 1 can be reduced, and the air conditioner 15 equipped with such a blower 1 can reduce the input of the equipment and the outdoor blow while securing a blown amount for realizing a predetermined heat exchange capability. Increase in noise can be suppressed.

  In the first embodiment of the present invention, the hub 3 is cylindrical. However, as shown in FIGS. 7 and 8, even if the inclined hub 16 is used, the effect of suppressing the flow loss on the hub side 6b is exhibited. Further, the chord length is longer than that of the hub side 6b, and even if the flow on the outer peripheral side 6a is promoted by guiding the blade tip vortex to the suction surface 10 side of the concave outer peripheral side 6a, The flow of the air does not deviate toward the outer peripheral side 6 a, and the flow velocity of the air current on the outer peripheral side 6 a can be suppressed low, and the effect of suppressing the increase in friction loss on the pressure surface 9 and the negative pressure surface 10 on the outer peripheral side 6 a of the blade 6 can be exhibited.

  In Embodiment 1 of the present invention, the number of six blades is two, but the same effect can be obtained with three or more blades.

  In the first embodiment of the present invention, the orifice ring 4 is enclosed only on the discharge side of the impeller 2. However, the same effect can be obtained by surrounding the entire outer periphery of the impeller.

(Embodiment 2)
FIG. 9 is a meridional sectional view of a blower having a partial rotation locus in the second embodiment of the present invention. FIG. 10 shows a condition in which the ratio between the radial interval S between the first orifice ring and the second orifice ring and the impeller outer diameter D2 and predetermined aerodynamic characteristics (air volume, static pressure) are secured in the second embodiment. It is a figure which shows the characteristic of the input relationship of the motor of a fan. The same constituent elements as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 9, reference numeral 17 denotes an orifice ring that surrounds the discharge-side outer periphery of the impeller 2, and includes a substantially cylindrical first orifice ring 18 having a discharge-side tip portion as an open end 18a, and a first orifice. A second orifice ring 19 that is substantially concentrically provided on the outside of the ring 18 and has an axial height higher than that of the first orifice ring, and the suction side 18b of the first orifice ring and the suction of the second orifice ring 19 It comprises a curved portion 20 that smoothly connects the side 19b.

  As a result, the curved portion 20 connecting the first orifice ring 18 and the second orifice ring 19 does not have an end on the suction side. Therefore, when the airflow flows from the outer periphery of the blade 6 not surrounded by the orifice ring 18, There is no smooth flow and flows between the wings. Further, near the outer peripheral side 6a and the outer peripheral end 6d of the blade 6, the loss due to the fluctuation of the blade tip vortex can be suppressed without disturbing the blade tip vortex of the suction surface 10 near the trailing edge. In addition, the loss due to fluctuations in the wake vortex is kept small.

  As a result, in the blower 1 having the impeller 2 of the cylindrical hub 5, the flow is shifted to the outer peripheral side 6a of the blade 6 to suppress an increase in friction loss on the pressure surface 9 and the suction surface 10 of the blade 6, When the orifice ring 15 surrounding the discharge side outer periphery of the blade 6 is used, the disturbance of the inflow air flow from the suction side outer periphery of the blade 6 is suppressed, and the fluctuation of the blade tip vortex and the blade wake vortex on the outer peripheral side 6a of the blade 6 is suppressed. The accompanying loss is kept small, the air efficiency of the blower 1 is further improved, the input to the motor 3 of the blower 1 is kept low, and the increase in blowing noise accompanying fluctuations in the blade tip vortex and the wake vortex is suppressed.

Furthermore, here, when the radial distance between the first orifice ring 18 and the second orifice ring 19 is S, and the outer diameter of the impeller 2 is D2, S / D2 is 0.020-0. By setting the value to 092, the blower under the condition that the distance S between the two orifice rings 18 and 19 in FIG. 10 and the ratio S / D2 of the impeller outer diameter D2 and the predetermined aerodynamic characteristics (air volume, static pressure) are ensured. 1
As shown in the characteristic diagram of the relationship with the ratio of input to the blower 1 having the conventional orifice ring 4 of the motor 3, the input to the blower 1 having the conventional orifice ring 4 tends to be reduced to 1 or less. it can.

  As described above, the impeller and the blower according to the present invention promote the generation of the blade tip vortex on the blade outer peripheral side, and suppress the disturbance of the flow on the blade outer peripheral side due to the collapse of the blade tip vortex. However, the flow from the hub side does not deviate toward the outer peripheral side and the air flow velocity on the outer peripheral side does not increase, and the increase in friction loss on the pressure surface and the suction surface on the outer peripheral side of the blade is suppressed. Furthermore, the flow on the suction side outer periphery that is not surrounded by the orifice ring is also smoothly introduced, and the fluctuations of the blade tip vortex and the wake vortex on the outer periphery side of the blade are suppressed. Therefore, an increase in the blowing noise of the blower equipped with such an impeller is suppressed, the aerodynamic efficiency of the blower is improved, and the input of the blower motor can be reduced.

  Therefore, it is possible to achieve both the improvement of the blowing efficiency of the outdoor unit using such an impeller and blower and the high heat exchanging ability as a heat pump unit, and further noise reduction. It can be applied not only to refrigeration and refrigeration equipment such as household refrigerator-freezers and vending machines, heat pump equipment such as water heaters, and electronic equipment having thermoelectric components, but also to AV equipment and waste heat recovery equipment.

DESCRIPTION OF SYMBOLS 1 Blower 2 Impeller 3 Motor 4, 17 Orifice ring 5, 16 Hub 6 Blade 12 Heat exchanger 14 Box 18 First orifice ring 18a Open end 19 Second orifice ring 20 Curved portion

Claims (7)

It consists of a hub provided at the center of rotation and a plurality of blades provided around the hub, and the radial cross-sectional shape of the blades is a concave curve with respect to the suction side on the outer peripheral side, and the suction side on the hub side The convex curve on the hub side is substantially arc-shaped, and the value of the radius of curvature of the substantially arc-shaped convex curve decreases from the front edge side to the rear edge side of the blade. Impeller. 2. The impeller according to claim 1, wherein the hub has a substantially cylindrical shape in which an inner diameter of a front edge and an inner diameter of a rear edge of the blade are substantially the same. The impeller according to claim 2, wherein D1 / D2 is 0.135 to 0.368, where D1 is a diameter of the substantially cylindrical hub and D2 is an outer diameter of the impeller. A blower comprising: a motor; an impeller according to any one of claims 1 to 3; and an orifice ring surrounding a discharge side of the impeller. The orifice ring has a substantially cylindrical first orifice ring that surrounds the discharge-side outer periphery of the impeller and has a discharge-side tip portion as an open end, and a substantially concentric circle provided outside the first orifice ring. And a second orifice ring having an axial height higher than that of the first orifice ring, and a curved portion that smoothly connects the suction side of the first orifice ring and the suction side of the second orifice ring. The blower according to claim 4. S / D2 is 0.020 to 0.092, where S is the radial distance between the first orifice ring and the second orifice ring and the outer diameter of the impeller is D2. The blower according to claim 5. It consists of a fin tube type heat exchanger that performs heat exchange between air and refrigerant, a blower according to any one of claims 4 to 6 , and a box that houses the heat exchanger and the blower. Air conditioner characterized by.