Air supply device

Abstract

The invention provides an air blowing device. The impeller has a main plate and a plurality of blades arranged on the main plate and arranged in the circumferential direction, and each blade has: a blade leading edge section having a blade inclined section in which the axial height increases from the radially inner end toward the radially outer end; and a blade main body section which is connected to the blade front edge section and extends in the radial direction, the gap [delta] between the top plate section and the upper end surface in the axial direction of the blade main body section being 15% or more of the height H in the axial direction of the blade main body section, and the length cL in the radial direction of the blade inclined section of the blade front edge section being greater than the height cH in the axial direction of the inclined section.

Description

Technical Field

[0001] The present invention relates to a blowing device. Background Art

[0002] For example, Patent Document 1 (Japanese Patent Laid-Open Publication No. 2014-139412) discloses an existing blower. The blower includes a multi-blade centrifugal fan that rotates around a central axis extending vertically, and a scroll housing that houses the multi-blade centrifugal fan. An air suction port is provided in the upper wall of the scroll housing, and an air blowout port is provided in the side wall of the scroll housing. The multi-blade centrifugal fan includes a hub that rotates around the central axis and a plurality of blades that are arranged at a predetermined interval in the circumferential direction on the hub.

[0003] In the blower having the above structure, when the multi-blade centrifugal fan rotates, air flows into the interior of the scroll housing through the air suction port. The air flowing into the interior of the scroll housing flows between adjacent blades and accelerates along the blades toward the radially outer side. The air that has been accelerated toward the radially outer side is blown out radially outward of the multi-blade centrifugal fan and exhausted to the outside through the air blowout port. Summary of the Invention

[0004] Problems to be Solved by the Invention

[0005] In the blowing device described in Patent Document 1, a part of the air exhausted radially outward of the blades flows back radially inward. Therefore, there is a problem that the blowing efficiency of the blower is reduced.

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a blowing device that prevents backflow and improves blowing efficiency.

[0007] Means for Solving the Problems

[0008] In an exemplary embodiment of the present invention, a blowing device is provided. The blowing device includes: an impeller that can rotate about a central axis extending in the axial direction; a motor connected to the impeller and capable of rotationally driving the impeller; and a housing that houses the impeller and the motor. The housing has a top plate portion, a bottom plate portion, a side wall portion connecting the top plate portion and the bottom plate portion, and an air inlet and an air outlet that open in the housing. The air inlet is disposed in the top plate portion at a position where at least a part thereof axially overlaps with the impeller. The impeller has a main plate and a plurality of blades disposed on the main plate and arranged in the circumferential direction. The blades have: a blade leading edge portion having a blade inclined portion whose axial height increases as it goes from the radially inner end toward the radially outer end; and a blade main body portion connected to the blade leading edge portion and extending in the radial direction. The clearance δ between the axially upper end surface of the blade main body portion and the top plate portion is 15% or more of the axial height H of the blade main body portion. The radial length cL of the inclined portion of the blade leading edge portion is larger than the axial height cH of the inclined portion. Description of the Drawings

[0009] Figure 1 FIG. 6 is a perspective view of the blowing device 100 of the present embodiment.

[0010] Figure 2 FIG. 10 is a top view showing the inside of the blowing device 100.

[0011] Figure 3 FIG. 14 is a longitudinal sectional view of the centrifugal fan 1 taken along a plane including the central axis.

[0012] Figure 4 FIG. 18 is a top view showing the impeller 10 of the centrifugal fan 1.

[0013] Figure 5 FIG. 22 is a schematic view showing a part of the blowing device 100.

[0014] Symbol Description

[0015] 1, 1A—centrifugal fan, 10, 10A—impeller, 20—cup-shaped portion, 23—cylindrical portion, 30—main plate, 30a—upper surface, 30b—lower surface, 31—main plate inclined portion, 31a—outer concave portion of the main plate, 31b—first inner concave portion of the main plate, 31c—second inner concave portion of the main plate, 40—blade, 41—blade inclined portion, 50—ring-shaped portion, 51—lower surface, 52—outer peripheral surface, 53—ring-shaped portion inclined portion, 60—curved surface portion, 80—base portion, 81—base plate, M—motor, 100—blowing device. Detailed Description of the Embodiment

[0016] Hereinafter, an exemplary embodiment of the present invention will be described with reference to the drawings. Refer to Figures 1 to 5A description will be given. In addition, the scope of the present invention is not limited to the following embodiments, and can be arbitrarily changed within the scope of the technical idea of the present invention. In the following drawings, in order to facilitate understanding of each structure, the scale, quantity, etc. in each structure may sometimes be different from the actual structure.

[0017] In the following description, the direction along the central axis AX is referred to as the axial direction, the direction orthogonal to the central axis AX is referred to as the radial direction, and the direction along the rotational direction is referred to as the circumferential direction. The shape or positional relationship of each part will be described with the central axis AX direction as the up and down direction. However, this is only to define the up and down direction for ease of explanation, and does not limit the orientation of the air supply device 100, the impeller 10, and the centrifugal fan 1 of the present invention during use.

[0018] Figure 1 is a perspective view showing the air supply device 100 of the embodiment, Figure 2 is a top view showing the inside of the air supply device 100. Figure 3 is a longitudinal sectional view of the centrifugal fan 1 taken along a plane including the central axis. Figure 4 is a top view showing the impeller 10 of the centrifugal fan 1. Figure 5 is a schematic view showing a part of the air supply device 100. Hereinafter, each part will be described in detail.

[0019] The housing 70 has a top plate portion 71, a bottom plate portion 72, a side wall portion 73, an air inlet 74, an air outlet 75, and a throttle portion 76. The centrifugal fan 1 is disposed inside the housing 70.

[0020] The top plate portion 71 is located on the upper side in the axial direction of the centrifugal fan 1. The top plate portion 71 is a plate-like shape extending in the radial direction, and the air inlet 74 is disposed thereon. The top plate portion 71 is opposed to the impeller 10 of the centrifugal fan 1 with a gap δ to be described later. The bottom plate portion 72 is located on the lower side in the axial direction of the centrifugal fan 1. The bottom plate portion 72 is a plate-like shape extending in the radial direction, and the base portion 80 of the centrifugal fan 1 is fixed to the bottom plate portion 72. The side wall portion 73 connects the top plate portion 71 and the bottom plate portion 72 and is disposed around the centrifugal fan 1.

[0021] In addition, various methods such as screw fixing and fitting can be used for the method of fixing the base portion 80 to the bottom plate portion 72. At the time of fixing, a vibration-proof member (not shown) may be interposed between the base portion 80 and the bottom plate portion 72. In addition, the base portion 80 may not be fixed to the bottom plate portion 72. For example, it may be fixed to the side wall portion 73 as long as the centrifugal fan 1 is fixed to the housing 70.

[0022] The intake port 74 is circular and is positioned so as to axially overlap at least a portion of the impeller 10. The exhaust port 75 is rectangular and is positioned radially outward of the impeller 10. When the centrifugal fan 1 is driven, fluid flows into the interior of the casing 70 through the intake port 74 and is discharged from the exhaust port 75 to the exterior of the casing 70. The diameter of the imaginary circle S connecting the radially outer ends of the blade leading edge 401 is 90% to 110% of the diameter of the intake port 74.

[0023] The shapes of the air intake port 74 and the air exhaust port 75 are not limited thereto. For example, the air intake port 74 may be rectangular, triangular, or elliptical, and the air exhaust port 75 may be triangular, circular, or elliptical.

[0024] The throttle portion 76 connects the sidewall portion 73 and the exhaust port 75. The width of the throttle portion 76 is the same as or smaller than the diameter of the impeller 10. This allows for a reduction in the size of the housing 70, and thus the air supply device 100, while also increasing the pressure of the fluid discharged from the housing 70. The width of the throttle portion 76 may be constant, or may increase or decrease as it moves from the sidewall portion 73 toward the exhaust port 75.

[0025] Figure 3 is a cross-sectional view showing the centrifugal fan 1 of this embodiment. Figure 4 Cross-sectional view along line AA. Figure 4 It is a plan view showing impeller 10 of centrifugal fan 1 .

[0026] like Figure 3 As shown, the centrifugal fan 1 includes an impeller 10, a base 80, and a motor M. The centrifugal fan 1 is a centrifugal fan that sends air radially outward by utilizing centrifugal force due to the rotation of the impeller 10. Each component will be described in detail below.

[0027] The motor M includes a motor body (not shown) and a motor housing 12 that houses the motor. The motor M has a rotating shaft 11 extending axially. The motor M rotates the impeller 10 about the central axis AX by driving the motor body. The motor body can, for example, have a stator portion as a fixed assembly and a rotor portion as a rotating assembly. The rotor portion can, for example, rotate relative to the stator portion about the central axis AX.

[0028] The impeller 10 includes a cup-shaped portion 20, a main board 30, blades 40, a ring-shaped portion 50, and a curved surface portion 60. The cup-shaped portion 20 opens downward along the axial direction with the central axis AX as the center. At least a part of the motor M is accommodated inside the cup-shaped portion 20. The cup-shaped portion 20 is a bottomed cylindrical shape having a circular cover portion 21 and a cylindrical portion 23. The cylindrical portion 23 extends downward along the axial direction from the radially outer side of the cover portion 21. The radial distance of the outer peripheral surface of the cylindrical portion 22 from the central axis AX gradually increases as it faces the lower side in the axial direction. In addition, the outer peripheral surface of the cylindrical portion 22 is not limited to this, and for example, the radial distance from the central axis AX may also be constant.

[0029] The cover portion 21 extends radially with respect to the central axis AX. The cover portion 21 is fixed to the rotating shaft 11. Therefore, by the drive of the motor M, the impeller 10 rotates with the central axis AX as the center. The rotation direction of the impeller 10 is the direction from the position of the radially outer end of the blade 40 to the position of the radially inner end of the blade 40 in the circumferential direction. That is, the rotation direction of the impeller 10 is Figure 2 the clockwise direction in

[0030] The main board 30 is an annular portion that extends from the lower side of the cup-shaped portion 20 toward the radially outer side. As Figure 2 shown, when viewed from above, at least a part of the main board 30 is exposed in the axial direction. That is, when viewed from above, the main board 30 is exposed inside the ring-shaped portion 50 in the radial direction. Therefore, by the rotation of the impeller 10, the air above the impeller 10 is sucked in. The outer side of the main board 30 has a main board inclined portion 31. The axial distance between the lower end of the ring-shaped portion 50 and the upper surface of the main board 30 increases as it faces the radially outer side in the main board inclined portion 31. Therefore, the cross-sectional area of the air ejection port that is sent out toward the radially outer side can be enlarged, and the exhaust efficiency can be improved.

[0031] The lower surface 30b of the main board 30 has a plurality of concave portions that are recessed upward in the axial direction at intervals in the circumferential direction and are located radially inside the ring-shaped portion 50. The plurality of concave portions include a main board outer concave portion 31a, a main board inner first concave portion 31b, and a main board inner second concave portion 31c. A plurality of main board outer concave portions 31a are arranged at intervals in the circumferential direction on the radially outer side. Therefore, the rotational balance correction of the impeller 10 can be performed. A part of the radially outer side of the main board outer concave portion 31a overlaps with the main board inclined portion 31 in the axial direction. Therefore, by forming the main board outer concave portion 31a at the radially outer end as much as possible, the effect of rotational balance correction can be increased.

[0032] A plurality of main board inner first concave portions 31b are provided at intervals in the circumferential direction on the radially inner side of the main board outer concave portion 31a. Therefore, the main board inner first concave portion 31b is a weight reduction portion, and it is possible to prevent shrinkage holes and lighten the weight during the forming of the impeller 10, and the rotational balance correction can also be performed.

[0033] A plurality of second concave portions 31c on the inner side of the main board are provided at intervals in the circumferential direction on the radially outer side of the first concave portion 31b on the inner side of the main board. Therefore, the second concave portion 31c on the inner side of the main board is a weight-reducing portion, which can prevent shrinkage holes and lighten the weight during the forming of the impeller 10, and can perform rotational balance correction.

[0034] In addition, due to the relationship of the axial thickness of the main board 30, if the axial depth of ensuring the outer concave portion 31a of the main board is compared with the axial depth of ensuring the first concave portion 31b or the second concave portion 31c on the inner side of the main board, the former is more difficult. That is, the positive balance adjustment of a hammer or a clip, etc. is preferably performed in the first concave portion 31b or the second concave portion 31c on the inner side of the main board where the axial depth is easily ensured. On the other hand, it is preferably only the balance correction during die forming that is performed in the outer concave portion 31a of the main board. In this way, the primary balance adjustment during die forming is performed in the outer concave portion 31a of the main board, and the secondary balance adjustment after die forming is performed in the first concave portion 31b or the second concave portion 31c on the inner side of the main board, thereby enabling an impeller with excellent mass productivity to be realized.

[0035] The curved surface portion 60 connects the upper surface 30a of the main board 30 and the outer peripheral surface of the cup-shaped portion 20. The curved surface portion 60 is a curved surface that protrudes toward the radially inner side.

[0036] The curved surface portion 60 causes the flow direction of the air that is sucked from the upper side of the impeller 10 along the outer peripheral surface of the cup-shaped portion 20 downward to continuously change from the direction along the outer peripheral surface of the cup-shaped portion 20 to the direction along the upper surface 30a of the main board 30 toward the radially outer side as it moves toward the radially outer side. Therefore, an increase in the flow resistance of the air that is sucked from the upper side of the impeller 10 and exhausted toward the radially outer side can be suppressed, thereby improving the air supply efficiency.

[0037] A part of the curved surface portion 60 overlaps with the first concave portion 31b and the second concave portion 31c on the inner side of the main board in the axial direction. Therefore, the portion thickened due to the presence of the curved surface portion 60 can be thinned, thereby preventing shrinkage holes.

[0038] The annular portion 50 is a circular ring-shaped portion connected to the outer ends of the blades 40. The radially inner end of the annular portion 50 is located at a position substantially coinciding with the outer end of the main board 30 in the radial direction or is located outside the outer end of the main board 30. Therefore, the impeller 10 can be formed by punching the die up and down.

[0039] The upper surface of the annular portion 50 has an annular portion recess 55. A plurality of annular portion recesses 55 are arranged at intervals in the circumferential direction. Therefore, the rotational balance correction of the impeller 10 can be performed. The annular portion 50 has an annular portion inclined portion 53 that connects the lower surface 51 and the outer peripheral surface 52. The radial distance from the central axis AX to the annular portion inclined portion 53 becomes longer as it goes from the lower side in the axial direction to the upper side. Therefore, the cross-sectional area of the air ejection port that ejects air radially outward can be enlarged, and the exhaust efficiency can be improved. However, the annular portion 50 may also have an annular portion inclined portion 53 that connects the lower surface 51 and the upper surface of the annular portion 50. That is, the annular portion 50 may not have the outer peripheral surface 52, and the annular portion inclined portion 53 extends from the lower surface 51 to the upper surface of the annular portion 50. Thereby, the cross-sectional area of the ejection port can be further enlarged, and thus the exhaust efficiency can be further improved.

[0040] In the axial direction, when the radial position of the annular portion inclined portion 53 at the position of the upper surface of the annular portion 50 is outside the radial position of the outer peripheral surface 52 of the annular portion 50, as Figure 1 and Figure 2 shown, the outer peripheral surface 52 of the annular portion 50 extends in the axial direction. In the axial direction, when the radial position of the annular portion inclined portion 53 at the position of the upper surface of the annular portion 50 is the same as or inside the radial position of the outer peripheral surface 52 of the annular portion 50, the outer peripheral surface of the annular portion 50 becomes a circular linear shape when viewed from above where the upper surface of the annular portion 50 intersects the annular portion inclined portion 53.

[0041] A plurality of blades 40 are arranged in the circumferential direction on the upper side of the main board 30. The number of blades 40 is, for example, 11. The radially inner ends of the respective blades 40 are connected to the curved surface portion 60. The blade 40 has a blade leading edge portion 401 and a blade main body portion 402. The blade leading edge portion 401 has a blade inclined portion 41 whose axial height increases as it goes from the radially inner end to the radially outer end. The blade main body portion 402 is connected to the blade leading edge portion 401 and extends in the radial direction.

[0042] The blade 40 is connected to the lower surface 51 of the annular portion 50. Therefore, the fixing of the annular portion 50 and the blade 40 can be strengthened. The outer end of the blade 40 is connected to the annular portion inclined portion 53. Therefore, the air fluidity from the blade 40 to the annular portion 50 can be improved.

[0043] The blade 40 is connected to the outer peripheral surface 52 of the annular portion 50 in the radial direction. Therefore, the radial length of the blade 40 becomes larger, and the exhaust efficiency is improved. Moreover, the generation of turbulent flow at the connection portion between the blade 40 and the annular portion 50 can be suppressed.

[0044] The blade 40 has a blade inclined portion 41 connecting the inner end of the blade 40 and the upper end of the blade 40. Therefore, the opening area of the opening portion 90 between the cup-shaped portion 20 facing upward and the radial inner end of the blade 40 is further increased, thereby further improving the suction efficiency from the suction port facing upward.

[0045] The radially outer end of the rotationally forward surface of the blade 40 is positioned rotationally backward relative to any tangent line of the rotationally forward surface of the blade 40. Therefore, air resistance applied to the blade 40 can be reduced, thereby suppressing power consumption.

[0046] The base portion 80 is located below the impeller 10. The base portion 80 includes an axially extending cylindrical portion 82 and a base plate 81 extending radially outward from the lower side of the cylindrical portion 82. The base plate 81 supports the motor M from below. Therefore, the base plate 81 rotatably supports the impeller 10 via the motor M.

[0047] In the centrifugal fan 1 having the above structure, when the impeller 10 is driven by the motor body to rotate about the central axis AX relative to the base portion 80, centrifugal force propels air radially outward, thereby delivering air. The negative pressure generated by the radially outward delivery of air causes air above the impeller 10 to be drawn in through the opening 90. The air drawn downward from the opening 90 flows along the outer circumferential surface of the cup-shaped portion 20 and the curved surface portion 60, with the flow direction smoothly changing from the bottom to the radially outward direction, resulting in radially outward delivery of air. In this embodiment, the centrifugal fan 1 can improve both intake and exhaust efficiency, thereby enhancing air delivery efficiency.

[0048] Further references Figure 5 (a) and (b) of FIG. 1 illustrate the positional relationship between the casing 70 and the impeller 10.

[0049] The gap δ between the axial upper end surface of the blade body 42 and the top plate 71 is greater than 15% of the axial height H of the blade body 402 . The radial length cL of the blade inclined portion 41 of the blade leading edge 401 is greater than the axial height cH of the blade inclined portion 41 .

[0050] The axial height cH of the blade inclined portion 41 is equal to or greater than one-third of the axial height H of the blade main body portion 402. This can further suppress the backflow of the fluid to the air intake port.

[0051] The radial length cL of the blade leading edge portion 401 is equal to or less than half the total length L of the blade 40. This can further suppress the backflow of the fluid to the air intake port.

[0052] The radially outer end portion of the blade leading edge portion 401 is arranged radially inward of the radially outer end of the intake port 74 .

[0053] As described above, an exemplary embodiment of the present invention has been described with reference to the accompanying drawings, but the present invention is not limited to this example. The shapes and combinations of the respective components shown in the above example are examples, and various changes can be made according to design requirements and the like without departing from the gist of the present invention.

Claims

1. An air supply device, characterized in that, Comprising: An impeller that can rotate about a central axis extending axially; A motor connected to the impeller and capable of rotationally driving the impeller; And A housing that houses the impeller and the motor, The housing has a top plate portion, a bottom plate portion, a side wall portion connecting the top plate portion and the bottom plate portion, and an air inlet and an air outlet opening in the housing, The air inlet is disposed on the top plate portion at a position where at least a part thereof overlaps the impeller axially, The impeller has a main plate and a plurality of blades arranged circumferentially on the main plate, The blades have: A blade leading edge portion having an inclined portion whose axial height increases as it goes from the radially inner end toward the radially outer end; And A blade main body portion connected to the blade leading edge portion and extending radially, The clearance δ between the axially upper end face of the blade main body portion and the top plate portion is 15% or more of the axial height H of the blade main body portion, The radial length cL of the inclined portion of the blade leading edge portion is larger than the axial height cH of the inclined portion.

2. The air supply device according to claim 1, wherein The axial height cH of the inclined portion is one-third or more of the axial height H of the blade main body portion.

3. The air supply device according to claim 1, wherein The radial length cL of the blade leading edge portion is half or less of the total length L of the blade.

4. The air supply device according to claim 1, wherein The diameter of the imaginary circle connecting the radially outer ends of the blade leading edge portion is 90% - 110% of the diameter of the air inlet.

5. The air supply device according to claim 1, wherein The radially outer end of the blade leading edge portion is disposed radially inward of the radially outer end of the air inlet.

6. The air supply device according to claim 1, wherein The side wall portion has a throttling portion, The width of the throttling portion is the same as or smaller than the diameter of the impeller.

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