CN116601392A

CN116601392A - Air supply device

Info

Publication number: CN116601392A
Application number: CN202180084260.XA
Authority: CN
Inventors: 田中诚; 小见山嘉浩; 冈田成浩
Original assignee: Toshiba Carrier Corp
Current assignee: Toshiba Carrier Corp
Priority date: 2021-03-25
Filing date: 2021-03-25
Publication date: 2023-08-15
Also published as: WO2022201468A1; JPWO2022201468A1; JP7458552B2

Abstract

Provided is an air blowing device capable of efficiently sucking air from a bell mouth and blowing the air with high efficiency. The air blowing device (6) is provided with: a ring-shaped bell mouth (7); a flat downstream side surface (19) connected to a downstream side end (7 b) of the bell mouth (7); and an impeller (23) that sucks air from the bell mouth (7) and blows the air out in a direction along the downstream side surface (19). The impeller (23) is provided with: a main plate portion (31) which is substantially parallel to the downstream side surface (19) and which spreads radially; and a plurality of open-type blade sections (32) protruding from the main plate section (31) toward the downstream side surface (19) and the flare opening (7) and arranged in a ring shape. The outermost diameter of the plurality of blade sections (32) is larger than the outermost diameter of the main plate section (31). The protruding ends (32 a) of the plurality of blade sections (32) have a first portion (45) disposed in proximity to the downstream side surface (19) and a second portion (46) protruding toward the upstream side end (7 a) of the flare (7) than the downstream side end (7 b) of the flare (7).

Description

Air supply device

Technical Field

Embodiments of the present invention relate to an air blowing device.

Background

A blower device including a turbo fan (turbo fan) and a bell mouth (bell mouth) provided on a suction side of the turbo fan is known.

Prior art literature

Patent literature

Patent document 1: international publication No. 2009/054316

Disclosure of Invention

Problems to be solved by the invention

A turbofan of a conventional blower device includes a shroud (shroud) that connects tips of blades (paddles). The shield is disposed adjacent the flare.

In the conventional blower device in which the shroud of the turbo fan is disposed in the vicinity of the bell mouth, the inventors found that a vortex flow occurs in a region on the rear surface side (inside of the case) of the bell mouth and on the radially outer side of the shroud. The vortex reduces the volume of air drawn in by the blower.

Accordingly, an object of the present invention is to provide an air blower that can efficiently suck air from a bell mouth and blow air with high efficiency.

Means for solving the problems

An air blowing device according to an embodiment of the present invention includes: an annular flare; a flat downstream side surface connected to a downstream side end of the bell mouth; and an impeller that sucks air from the bell mouth and blows the air in a direction along the downstream side surface. The impeller is provided with: a main plate portion which is substantially parallel to the downstream side surface and radially spreads; and a plurality of open-type blade portions protruding from the main plate portion toward the downstream side surface and the flare, and arranged in a ring shape. The outermost diameter of the plurality of blade portions is larger than the outermost diameter of the main plate portion. The protruding ends of the plurality of vane portions have a first portion disposed adjacent to the downstream side surface and a second portion protruding toward the upstream side end of the flare than the downstream side end of the flare.

In the blower according to the embodiment, it is preferable that an outlet angle of a root end of each of the blade portions connected to the main plate portion is larger than an inlet angle of the root end.

Further, in the blower according to the embodiment, it is preferable that the root end of each of the blade portions connected to the main plate portion is linear.

In the blower according to the embodiment, it is preferable that the thickness of each of the blade portions is smaller than the thickness of the main plate portion.

Further, in the blower according to the embodiment, it is preferable that the number of the plurality of blade portions is a prime number. Preferably, an angle between a first line segment connecting a rear edge of the first blade portion and the rotation center line and a second line segment connecting a rear edge of the second blade portion adjacent to the first blade portion and the rotation center line, as viewed in a direction along the rotation center line of the impeller, is 25 degrees or more.

In the blower according to the embodiment, it is preferable that the blower further includes a reinforcing member that connects the second portions of the plurality of blade portions.

Effects of the invention

According to the present invention, it is possible to provide an air blowing device capable of efficiently sucking air from a bell mouth and blowing air with high efficiency.

Drawings

Fig. 1 is a schematic perspective view of an indoor unit of a refrigeration cycle apparatus including an air blower according to an embodiment of the present invention.

Fig. 2 is a schematic longitudinal cross-sectional view of an indoor unit of a refrigeration cycle apparatus including an air blower according to an embodiment of the present invention.

Fig. 3 is a plan view of the impeller according to the present embodiment.

Fig. 4 is a perspective view showing an impeller according to the present embodiment from the bottom surface side.

Fig. 5 is a longitudinal sectional view of the impeller and the bell mouth according to the present embodiment.

Fig. 6 is a perspective view of a blade portion of the impeller according to the present embodiment.

Fig. 7 is a graph comparing the characteristics of the impeller according to the present embodiment with those of the impeller of the comparative example.

Fig. 8 is a schematic view of inlet and outlet angles of a blade portion of the impeller according to the present embodiment.

Fig. 9 is a graph comparing the characteristics of the impeller according to the present embodiment with those of the impeller of the comparative example.

Fig. 10 is a perspective view showing another example of the impeller according to the present embodiment from the bottom surface side.

Fig. 11 is a perspective view showing another example of the impeller according to the present embodiment from the bottom surface side.

Detailed Description

An embodiment of an air blowing device according to the present invention will be described with reference to fig. 1 to 11. In the drawings, the same or corresponding structures are denoted by the same reference numerals.

The refrigeration cycle apparatus according to the present embodiment includes an indoor unit 1 provided indoors as a use side and an outdoor unit (not shown) provided outdoors as a heat source side, as shown in fig. 1.

The refrigeration cycle apparatus further includes a refrigeration cycle (not shown). The refrigeration cycle includes a heat source-side heat exchanger (not shown), a compressor (not shown), a use-side heat exchanger 2, an expander (not shown), and a refrigerant pipe (not shown) through which a refrigerant flows to these devices. The refrigeration cycle may include a four-way valve (not shown) for switching between a cooling operation and a heating operation of the refrigeration cycle apparatus.

The indoor unit 1 houses a heat exchanger 2 on the use side of the refrigeration cycle. The outdoor unit houses a heat exchanger, a compressor, and a four-way valve on the heat source side of the refrigeration cycle. The expander may be housed in the indoor unit 1 or in the outdoor unit. The outdoor unit and the indoor unit are connected via a crossover pipe (not shown). The crossover pipe is a portion of the refrigerant pipe. The refrigeration cycle apparatus circulates a refrigerant between the heat exchanger on the outdoor unit side and the heat exchanger 2 on the indoor unit 1 side, and conditions indoor air.

The indoor unit 1 is installed in a room of a building. The indoor unit 1 is embedded in a ceiling of a room, suspended from a ceiling or a beam, or the like.

As shown in fig. 1 and 2, the indoor unit 1 according to the present embodiment includes a casing 5, a heat exchanger 2 provided in the casing 5, and a blower 6. The blower 6 includes an annular bell mouth 7 provided in the casing 5, and a turbo fan 8 that sucks air from the bell mouth 7 and blows the air into the heat exchanger 2.

The indoor unit 1 further includes an electric expansion valve (not shown) as an expander of the refrigeration cycle.

The case 5 is a case having a rectangular top surface, 4 rectangular side surfaces, and a rectangular bottom surface. The top surface of the box 5 is blocked by a top plate 11. A turbo fan 8 is provided on the lower surface of the top plate 11. The 4 sides of the case 5 are blocked by the side plates 12. The corners between the sides are inclined like a chamfer. The chamfer portion is blocked by the inclined plate 13.

The bottom surface of the case 5 is covered with a bottom plate 14. A circular suction port 16 for sucking air from below the indoor unit 1 is provided in the center of the bottom plate 14. A plurality of rectangular air outlets 17 for blowing air downward are provided in the outer edge portion of the bottom plate 14. Each of the blow-out ports 17 is along each side of the rectangular bottom surface of the case 5. Thus, the indoor unit 1 sucks in indoor air from the suction port 16 on the bottom surface of the casing 5, exchanges heat between the refrigerant and the air by the heat exchanger 2, and blows out the conditioned air from the air outlet 17 on the bottom surface of the casing 5.

The heat exchanger 2 is fixed to the ceiling 11 of the tank 5. The heat exchanger 2 is, for example, a fin-and-tube type in this embodiment, and includes a plurality of fins made of aluminum alloy arranged in order and a refrigerant tube penetrating a fan.

The heat exchanger 2 is provided inside the casing 5, and surrounds the turbine fan 8 radially outside. The inner peripheral surface of the heat exchanger 2 faces the turbo fan 8, and the outer peripheral surface of the heat exchanger 2 faces the inner surface of the side plate 12. The heat exchanger 2 has flat plate portions 2a opposed to the respective side plates 12 of the tank 5, and curved plate portions 2b which are curved so as to be opposed to the inclined plates 13 between the adjacent 2 side plates 12 and connect the adjacent two flat plate portions 2 a. There are 4 flat plate portions 2a and 3 curved plate portions 2b. That is, the heat exchanger 2 is not integrally continuous in a ring shape.

An annular flare 7 is provided at the suction port 16 of the bottom plate 14. The suction side opening edge of the flare 7, i.e., the upstream side end 7a of the flare 7 is connected to the outer face 14a of the bottom plate 14. The opening edge of the blow-out side of the horn mouth 7, i.e., the downstream side end 7b of the horn mouth 7, is connected to the inner surface 14b of the bottom plate 14. The inner surface 14b of the bottom plate 14 is flat, reaching the heat exchanger 2 from the downstream side end 7b of the bell mouth 7. The outer surface 14a of the bottom plate 14 is a flat upstream side surface 18 connected to the upstream side end 7a of the bell mouth 7, and the inner surface 14b of the bottom plate 14 is a flat downstream side surface 19 connected to the downstream side end 7b of the bell mouth 7.

A drain pan (not shown) for receiving dew condensation water generated on the surface of the heat exchanger 2 may be provided below the heat exchanger 2. During the cooling operation in which the heat exchanger 2 functions as an evaporator, moisture contained in the air passing through the heat exchanger 2, that is, indoor moisture, condenses on the surface of the heat exchanger 2, adheres to the heat exchanger 2 as dew condensation water, and drips from the heat exchanger 2. The drain pan receives dew condensation water falling from the heat exchanger 2. Dew water accumulated in the drain pan is pumped by a drain pump (not shown) provided in the casing 5, and is discharged to the outside of the indoor unit 1 through a drain pipe (not shown).

The drain pan preferably has a recess for receiving dew water in a portion as close as possible to the heat exchanger 2 in a planar portion extending from the downstream end 7b of the bell mouth 7 toward the heat exchanger 2. The drain pan is preferably formed of an insulating material integral with the floor 14 of the tank 5.

The turbofan 8 includes a fan motor 22 having a rotation shaft 21 extending in the vertical direction at the substantially center of the casing 5, and an impeller 23 integrally fixed to the rotation shaft 21.

The fan motor 22 rotationally drives the impeller 23. The fan motor 22 is fixed to the inner surface of the top plate 11 of the casing 5 via a fixing member 25.

The impeller 23 driven in rotation sucks air around the casing 5 from the bell mouth 7 of the suction port 16, blows the air radially in a direction along the inner surface 14b of the bottom plate 14, and blows the blown air toward the heat exchanger 2.

The center of the substantially annular heat exchanger 2, the rotation center of the turbo fan 8, the center of the circular suction port 16, and the center of the annular horn mouth 7 are aligned in plan view. The maximum outer diameter a of the turbofan 8 is larger than the opening diameter B of the bell mouth 7.

The rotation center line C of the impeller 23 coincides with the rotation shaft 21 of the fan motor 22, and extends in the vertical direction in a state where the indoor unit 1 is provided.

In the cooling operation of the air conditioner, the compressor of the outdoor unit discharges a high-temperature and high-pressure gas refrigerant and sends the gas refrigerant to the heat exchanger (condenser) outside the room. The outdoor heat exchanger exchanges heat between the refrigerant flowing through the outdoor heat exchanger and the outdoor air, and condenses the refrigerant. The condensed liquid refrigerant is sent to the indoor unit 1 through the refrigerant pipe. The indoor unit 1 expands the liquid refrigerant flowing in from the refrigerant pipe by an electric expansion valve, and sends the low-temperature gas-liquid mixed refrigerant to the heat exchanger 2 (evaporator). The heat exchanger 2 exchanges heat between the low-temperature refrigerant flowing through the inside thereof and the indoor air, thereby vaporizing the refrigerant. At this time, the indoor unit 1 blows out low-temperature air, and the room is cooled.

In the case of the air-conditioning system warming operation, the compressor of the outdoor unit discharges the high-temperature and high-pressure gas refrigerant and sends the gas refrigerant to the heat exchanger 2 (condenser) of the indoor unit 1. The heat exchanger 2 exchanges heat between the refrigerant flowing through the inside thereof and the indoor air, and condenses the refrigerant. At this time, the room is warmed by the high-temperature air blown out from the indoor unit 1.

Next, the impeller 23 will be described in detail.

Fig. 3 is a plan view of the impeller according to the present embodiment.

As shown in fig. 3 to 5 in addition to fig. 1 and 2, the impeller 23 of the blower 6 according to the present embodiment includes: a main plate portion 31 which is substantially parallel to the downstream side surface 19 connected to the flare 7 and which spreads radially; a plurality of vane portions 32 protruding from the main plate portion 31 toward the downstream side surface 19 and the bell mouth 7 and arranged in a ring shape; and a boss portion 33 provided in a central portion of the main plate portion 31.

The impeller 23 is an integrally molded product made of fiber reinforced plastic (Fiber Reinforced Plastics, FRP), aluminum alloy or magnesium metal. The impeller 23 is made of, for example, fiber reinforced plastic, and is integrally formed by a hand lay-up method.

The main plate 31 is a flat plate having a substantially uniform thickness. The main plate portion 31 is a collection of a plurality of petals 35 extending radially from the hub portion 33 to the impeller 23.

Each petal portion 35 includes a first edge portion 35a having a linear edge and a second edge portion 35b having a linear edge, and extends in a triangular shape or a tapered shape from the center side (the boss portion 33 side). The first edge 35a of each petal 35 is also referred to as a first edge of the main plate 31, and the second edge 35b of each petal 35 is also referred to as a second edge of the main plate 31.

With respect to the adjacent pair of petals 35, the first side 35a of one petal 35 is opposed to the second side 35b of the other petal 35. In other words, the first side portion 35a of one petal portion 35 and the second side portion 35b of the other petal portion 35 face each other with a gap therebetween in the circumferential direction of the main plate portion 31.

The shape of all petals 35 is substantially the same. The ends of the plurality of petals 35 located radially inward of the turbofan 8, that is, the root ends of the plurality of petals 35 tightly surround the outer periphery of the hub 33. In other words, with respect to the adjacent pair of petals 35, the root end of the first side 35a of one petal 35 coincides with the root end of the second side 35b of the other petal 35. The ends of the plurality of petals 35 located radially outward of the turbofan 8, that is, the protruding ends of the plurality of petals 35 are connected by an imaginary circle. The virtual circle corresponds to the outermost diameter D1 of the main plate 31.

The plurality of blade portions 32 and the hub portion 33 protrude from the main plate portion 31 in the same direction. The boss portion 33 has a truncated cone shape which becomes narrower as it is farther from the main plate portion 31. The protruding height of the plurality of blade portions 32 with respect to the main plate portion 31 is higher than the protruding height of the boss portion 33.

The number of the blade portions 32, that is, the number of pieces is a prime number, and in the present embodiment, 11 pieces.

The shape of all of the blade portions 32 is substantially the same. All of the blade portions 32 are plate-like bodies of uniform thickness. The plurality of blade portions 32 are open. That is, the impeller 23 does not have a shroud that connects the protruding ends 32a of the plurality of blade portions 32. Each blade 32 is connected only to the main plate 31, and is not connected to the hub 33.

The root end 32b of each blade portion 32 is an edge of each blade portion 32 connected to the main plate portion 31. The root end 32b of each blade portion 32 is connected to the first edge 35a of each petal portion 35. Each blade portion 32 protrudes from a first edge portion 35a of each petal portion 35. Thus, the root end 32b of each blade portion 32 has the same straight shape as the first edge portion 35a of each petal portion 35, and has a straight shape in accordance with the chord (chord).

Each blade portion 32 is inclined in the circumferential direction of the turbofan 8 and in a direction away from the second edge portion 35b of each petal portion 35. Further, each blade 32 is inclined radially outward of the turbofan 8 from the root end 32b toward the protruding end 32 a. Therefore, the outermost diameter D2 drawn by the plurality of blade portions 32 is larger than the outermost diameter D1 of the main plate portion 31.

The impeller 23 rotates in the direction R before the first side portion 35a and the second side portion 35b of each petal portion 35 to cause air to flow. That is, the front edge 41 of each blade 32 is located on the inner peripheral side of the impeller 23, and the rear edge 42 of the blade 32 is located on the outer peripheral side of the impeller 23.

The angle θ between the first line segment L1 connecting the rear edge 42 of the first blade portion 32 and the rotation center line C and the second line segment L2 connecting the rear edge 42 of the second blade portion 32 adjacent to the first blade portion 32 and the rotation center line C is preferably 25 degrees or more, as viewed from the direction along the rotation center line of the impeller 23 (fig. 3). That is, the number of blades 32 is preferably 13 or less, and in the present embodiment, 11 blades.

The protruding end 32a of each blade 32 has a first portion 45 disposed close to the downstream side surface 19 and a second portion 46 protruding toward the upstream side end 7a of the flare 7 than the downstream side end 7b of the flare 7. That is, the protruding end 32a of each blade 32 has a convex portion 47 that enters the inside of the flare 7. The convex portion 47 is formed to protrude in the shape of the flare 7. The second portion 46 is a ridge of the protruding portion 47. In the present embodiment, the first portion 45 of the vane 32 and the downstream side surface 19 are arranged to face each other with a spacing of about several millimeters. The interval between the impeller 23 and the bell mouth 7 is preferably as close as possible to the range in which the impeller 23 can smoothly rotate without interfering with the bell mouth 7.

The thickness of each blade portion 32 is thinner than the thickness of the main plate portion 31. Such a relationship of the wall thickness reduces the centrifugal force acting on the blade portions 32 as compared with the case where the wall thickness of each blade portion 32 is the same as the wall thickness of the main plate portion 31 or the case where the wall thickness of each blade portion 32 is thicker than the wall thickness of the main plate portion 31. The reduction in centrifugal force reduces the deformation of the blade portion 32, and prevents the reduction in air volume caused by the deformation of the blade portion 32. Further, the main plate portion 31 having a thicker wall thickness than the respective blade portions 32 reduces deformation of the blade portions 32 due to centrifugal force, and prevents a decrease in air volume due to deformation of the blade portions 32.

As shown in fig. 6, the blade portion 32 of the impeller 23 according to the present embodiment has a rectangular planar shape, for example, a shape close to a parallelogram. The root end 32b has a straight line shape connected to the first side portions 35a of the petal sections 35. The straight line connecting points a and b in fig. 6 is the root end 32b. The protruding end 32a is a nonlinear shape, and has a convex portion 47 protruding in a direction away from the root end 32b than an imaginary line VL passing through the protruding end of the rear edge 42 and parallel to the root end 32b. The protruding end 32a is a line connecting the points c, d, and e of fig. 6.

The line joining point a and point c of fig. 6 is the front edge 41 of the blade 32, and the line joining point b and point e of fig. 6 is the rear edge 42 of the blade 32.

The convex portion 47 has a linear edge 48 connected to the front edge 41 and parallel to the root end 32b and parallel to the main plate portion 31, and a curved edge 49 connecting the linear edge 48 to the rear edge 42. The straight line edge 48 is a straight line connecting the point c and the point d in fig. 6, and the curved line edge 49 is a curve connecting the point d and the point e in fig. 6. The straight edge 48 and a part of the curved edge 49 that is contoured to the flare 7 are the second portions 46 of the protruding ends 32a, and the remaining part of the curved edge 49 is the first portion 45 that is disposed close to the downstream side surface 19. That is, the remainder of the curvilinear edge 49 is substantially parallel to the root end 32b. Between the protruding end 32a and the flare 7 and between the protruding end 32a and the downstream side surface 19, there is a gap to such an extent that the rotation of the impeller 23 is not hindered. The gap is preferably 5 mm or less.

Fig. 7 is a graph showing a relationship between the static pressure P of the impeller and the flow rate Q of the impeller, and is a so-called P-Q characteristic.

Unlike the impeller 23 according to the present embodiment, the impeller of the comparative example does not have the convex portion 47 in each of the blade portions 32, and has a protruding end parallel to the downstream side surface 19 and the main plate portion 31. The protruding end of the impeller of the comparative example does not protrude into the bell mouth 7, but is disposed close to the downstream side surface 19 disposed on the same plane and connected to the bell mouth 7.

The P-Q characteristic of the impeller 23 according to the present embodiment is represented by a curve α1, and the P-Q characteristic of the impeller of the comparative example is represented by a curve γ1.

As shown in fig. 7, the impeller 23 according to the present embodiment can deliver a larger amount of air than the impeller of the comparative example. Further, the impeller 23 according to the present embodiment can obtain a higher static pressure than the impeller of the comparative example by being close to the bell mouth 7.

The inlet angle and the outlet angle of the vane portion 32 are expressed by angles based on the rotation direction of the impeller 23. That is, the inlet angle of the blade 32 is the angle formed by the advancing direction u of the blade 32 and the front direction of the blade arc, and the outlet angle of the blade 32 is the angle formed by the advancing direction u of the blade 32 and the rear direction of the blade arc.

As shown in fig. 8, the blade portion 32 of the impeller 23 according to the present embodiment has an inlet angle β1 of the root end 32b, an outlet angle β2 of the root end 32b, an inlet angle β3 of the projection end 32a, and an outlet angle β4 of the projection end 32 a.

Also, the outlet angle β2 of the root end 32b is larger than the inlet angle β1 of the root end 32b.

The entrance angle β3 of the protruding end 32a and the exit angle β4 of the protruding end 32a may be appropriately set according to the respective speed triangles. The protruding end 32a has a curved shape protruding toward the radially outer side of the impeller 23.

The airfoil shape of the blade portion 32 is a three-dimensional shape that smoothly continues from the linear root end 32b to the curved protruding end 32 a. Accordingly, the airfoil of each blade portion 32 is formed in a substantially uniform thickness plate shape that is curved so as to protrude radially outward of the impeller 23 as the protruding distance from the chord increases as the protruding end 32a approaches.

Fig. 9 is a graph showing a relationship between the static pressure P of the impeller and the flow rate Q of the impeller, and is a so-called P-Q characteristic.

Unlike the impeller 23 according to the present embodiment, the outlet angle β2 of the root end 32b of the impeller of the comparative example is smaller than the inlet angle β1 of the root end 32b. The P-Q characteristic of the impeller 23 according to the present embodiment is represented by a curve α2, and the P-Q characteristic of the impeller of the comparative example is represented by a curve γ2.

As shown in fig. 9, the impeller 23 according to the present embodiment can deliver a larger amount of air than the impeller of the comparative example. Further, the impeller 23 according to the present embodiment can obtain a higher static pressure than the impeller of the comparative example by being close to the bell mouth 7.

Fig. 10 and 11 are perspective views showing another example of the impeller according to the present embodiment from the bottom surface side.

As shown in fig. 10 and 11, the impellers 23A and 23B according to the present embodiment may include reinforcing members 51A and 51B for connecting the second portions 46 of the plurality of blade portions 32. The reinforcing members 51A and 51B are not formed to have a large difference in dimension between the outer dimension and the inner dimension in the radial direction as in the case of the shroud of the conventional impeller, but are formed to have a linear shape, for example, steel wires.

The reinforcing members 51A and 51B connect the second portions 46 of the adjacent pair of blade portions 32 to connect the second portions 46 of all the blade portions 32. All of the blade portions 32 may be connected by a single reinforcing member 51A or 51B, or all of the blade portions 32 may be connected by a plurality of reinforcing members 51A or 51B that connect two or more blade portions 32 fewer than all of the blade portions 32.

The reinforcing member 51A may be a simple circular shape and may be fixed in point contact with the second portion 46 of each blade 32 (fig. 10). The reinforcing member 51B may have a first straight portion 52 extending along the second portion 46 of each blade 32 and a second straight portion 53 extending between the adjacent pair of blades 32, and may be fixed in line contact with the second portion 46 of each blade 32 (fig. 11).

As described above, the blower 6 according to the present embodiment includes the annular bell mouth 7, the flat downstream side surface 19 connected to the downstream side end 7b of the bell mouth 7, and the impeller 23 that sucks air from the bell mouth 7 and blows the air in the direction along the downstream side surface 19. The impeller 23 includes a main plate portion 31 that is substantially parallel to the downstream side surface 19 and spreads radially, and a plurality of open vane portions 32. The outermost diameter D2 drawn by the plurality of blade portions 32 is larger than the outermost diameter D1 of the main plate portion 31. The protruding ends 32a of the plurality of vane portions 32 have a first portion 45 disposed close to the downstream side surface 19 and a second portion 46 protruding toward the upstream side end 7a of the flare 7 than the downstream side end 7b of the flare 7. Therefore, the blower 6 can prevent the air blown out from the impeller 23 from being disturbed in the flow, and prevent the air blowing efficiency from being lowered. The blower 6 can suck air from the bell mouth 7 connected to the flat downstream side 19, and generate a flow of air along the flat downstream side 19 without disturbance. Further, the blower 6 can easily increase the air volume as compared with a blower without the projection 47 by the projection 47 of the vane 32, which is the second portion 46 projecting from the downstream end 7b of the bell mouth 7 toward the upstream end 7a of the bell mouth 7.

Further, since the impeller 23 has no shroud, it can be integrally formed. Therefore, the impeller 23 eliminates a factor of occurrence of a failure such as a welding failure or a welding failure in joining the divided shroud to the blade portion, and can reduce an unbalance amount of the rotation balance as compared with a case of joining the divided shroud to the blade portion 32.

Further, the impeller 23 according to the present embodiment includes a plurality of blade portions 32 connected only to the main plate portion 31. Therefore, the impeller 23 can be easily reduced in weight as compared with a conventional impeller having a shroud or a frame, and can eliminate the obstruction of the air flow.

Further, the impeller 23 according to the present embodiment includes the blade portion 32, and the blade portion 32 includes the root end 32b which is a part of the edge of the main plate portion 31 and is connected to the first side portion 35a of each of the petal portions 35. Therefore, the impeller 23 can smoothly blow out the air flow to which energy is applied by the blade portion 32.

The impeller 23 according to the present embodiment includes a first side portion 35a of the petal portion 35 and a second side portion 35b of the petal portion 35 facing each other with a gap therebetween in the circumferential direction of the main plate portion 31. Therefore, the impeller 23 can blow out the air energized by the blade portion 32 through the gaps of the adjacent petal portions 35. Such air flow improves the blower function of the impeller 23. The gaps between the adjacent petals 35 improve workability of each step of the hand lay-up method when integrally forming the impeller 23, and facilitate parting.

Further, the impeller 23 according to the present embodiment includes a plurality of blade portions 32 having a projection height higher than that of the hub portion 33. Therefore, the impeller 23 reduces the airflow resistance of the hub portion 33, and the airflow can be easily pushed out by the blade portion 32.

Further, the outlet angle β2 of the root end 32b of each blade portion 32 of the impeller 23 according to the present embodiment is larger than the inlet angle β1 of the root end 32b of the blade portion 32. Accordingly, the air blowing amount of the air blowing device 6 is increased as compared with an air blowing device having an impeller with a root portion having an outlet angle β2 smaller than an inlet angle β1. In addition, the blower 6 can easily provide a higher static pressure than a blower including an impeller having an outlet angle β2 smaller than an inlet angle β1.

Further, the root ends 32b of the blade portions 32 of the impellers 23 according to the present embodiment are linear. Accordingly, the blower 6 can easily set the outlet angle β2 of the root end 32b of each blade 32 to be larger than the inlet angle β1 of the root end 32b of the blade 32.

The thickness of each blade portion 32 of the impeller 23 according to the present embodiment is smaller than the thickness of the main plate portion 31. Therefore, the impeller 23 reduces the deformation of the blade portion 32, and prevents the decrease in the air volume caused by the deformation of the blade portion 32.

The impeller 23 according to the present embodiment further includes a prime number of blade portions 32, and includes a pair of blade portions 32 adjacent to each other at an angle of 25 degrees or more with respect to a pair of line segments L1 and L2 connecting the rear edge 42 to the rotation center line C. Therefore, the impeller 23 reduces noise called pitch noise, reduces ventilation resistance generated between the adjacent blade portions 32, improves the air volume, and improves manufacturability when the impeller 23 is integrally formed.

The impeller 23 according to the present embodiment may further include a reinforcing member 51 that connects the second portions 46 of the plurality of blade portions 32. Therefore, even if the impeller 23 does not have a shroud, the weight of the impeller 23 as a whole can be reduced, the influence of centrifugal force on the blade portion 32 can be reduced, the drop in the air volume can be suppressed, and the flare 7 due to the deformation of the blade portion 32 can be prevented from colliding with the blade portion 32.

Therefore, according to the blower 6 of the present embodiment, air can be efficiently sucked from the bell mouth 7 and blown with high efficiency.

While the present invention has been described with reference to several embodiments, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

Description of the reference numerals

1 … indoor unit; 2 … heat exchanger; 2a … plate portion; 2b … curved plate portions; 5 … box; 6 … air supply device; 7 … flare; 7a … upstream side end; 7b … downstream side end; 8 … turbofan; 11 … top plate; 12 … side panels; 13 … inclined plate; 14 … bottom plate; 14a …;14b … inner surfaces; 16 … suction inlet; 17 … blow-out port; 18 … upstream side; 19 … downstream side; 21 … rotation axis; 22 … fan motor; 23. 23A, 23B … impellers; 25 … mount; 31 … main plate portion; 32 … blade portions; 32a … overhangs; 32b … root ends; 33 … hub portion; 35 … petals; 35a … first side; 35b … second side portion; 41 … front edge; 42 … trailing edge; 45 … first part; 46 … second part; 47 … convex portions; 48 … straight edges; 49 … curve edge; 51A, 51B … reinforcing members; 52 … first straight portions; 53 … second straight portions.

Claims

1. An air supply device is characterized in that,

the device is provided with:

an annular flare;

a flat downstream side surface connected to a downstream side end of the bell mouth; and

an impeller that sucks air from the bell mouth and blows the air in a direction along the downstream side surface;

the impeller is provided with:

a main plate portion which is substantially parallel to the downstream side surface and radially spreads; and

an open-type plurality of blade portions protruding from the main plate portion toward the downstream side surface and the flare, and arranged in a ring shape;

the outermost diameter of the plurality of blade parts is larger than the outermost diameter of the main plate part;

the protruding ends of the plurality of vane portions have a first portion disposed adjacent to the downstream side surface and a second portion protruding toward the upstream side end of the flare than the downstream side end of the flare.

2. The air supply device as set forth in claim 1, wherein,

the outlet angle of the root end of each blade portion connected to the main plate portion is larger than the inlet angle of the root end.

3. A blower device as set forth in claim 1 or 2, wherein,

the root end of each blade portion connected to the main plate portion is linear.

4. A blower device according to any one of claims 1-3, wherein,

the thickness of each blade portion is thinner than the thickness of the main plate portion.

5. The air supply device according to claim 1 to 4, wherein,

the number of the plurality of blade portions is a prime number;

an angle between a first line segment connecting a rear edge of a first blade portion and the rotation center line and a second line segment connecting a rear edge of a second blade portion adjacent to the first blade portion and the rotation center line, as viewed in a direction along the rotation center line of the impeller, is 25 degrees or more.

6. The air supply device according to any one of claims 1 to 5, wherein,

the blade part is provided with a reinforcing member for connecting the second parts of the blade parts.