Impeller

Abstract

This impeller includes: a rotation center body connected to a rotation shaft of a rotation drive source; a rim surrounding the rotation center body; a plurality of first blades arranged between the rotation center body and the rim; and a plurality of second blades arranged outside the rim. The inner diameter of the rim is equal to or larger than the outer dimension of the rotation drive source, and as a result, by using a simple structure without enlarging the overall structure, a cooling effect of the rotation drive source is improved, and failure due to heat generation is prevented in a situation where a high load is applied to a motor.

Description

impeller

[0001] The present invention relates to an impeller.

[0002] It is known that an axial flow fan is attached to the blower of an outdoor unit of an air conditioner (see, for example, Patent Document 1). Such an axial flow fan has different blades on the inside and outside of a cylindrical body, improving the forward airflow performance of the axial flow fan. This type of axial flow fan blade shape can be used not only in blowers for outdoor units, but also in axial flow fans in the blower parts of devices that blow air, such as electric fans, ventilation fans, and heating appliances.

[0003] Japanese Patent Application Publication No. 5-106592

[0004] In the axial flow fan described in Patent Document 1, when the motor that rotates the blades operates continuously or at high speeds, excessive loads are placed on it, causing it to generate heat and resulting in breakdowns. Therefore, a motor cooling structure is needed to suppress heat generation. Cooling methods include, for example, providing slits or the like in the exterior of the motor to allow outside air to flow toward the axial flow fan, providing a separate fan for air cooling near the motor to blow air toward the motor, and providing a heat sink on the exterior of the motor. However, providing slits or the like in the exterior has the problem of being ineffective in cooling, making it difficult to prevent breakdowns due to heat generation under heavy loads on the motor. Furthermore, providing a separate fan for air cooling near the motor provides a high cooling effect, but results in a larger device. Furthermore, providing a heat sink on the exterior of the motor also increases the size of the motor, requiring a large installation space around the motor.

[0005] The present invention was made through extensive research by the inventors in view of the above problems, and aims to provide a means that can improve the cooling effect of a rotary drive source with a simple structure without increasing the size of the overall structure.

[0006] The impeller of the present invention has a rotating center body connected to the rotating shaft of a rotary drive source, a rim surrounding the rotating center body, a plurality of first blades arranged between the rotating center body and the rim, and a plurality of second blades arranged outside the rim, and is characterized in that the inner diameter of the rim is equal to or larger than the outer dimension of the rotary drive source.

[0007] In the impeller of the present invention, the first blade faces the rotary drive source.

[0008] The impeller of the present invention is characterized in that the number of the first blades is equal to or greater than the number of the second blades.

[0009] In addition, the impeller of the present invention is characterized in that the first blades extend substantially radially between the rotation center body and a rim, with the axis of the rotation center body as the center.

[0010] The impeller of the present invention is characterized in that the fluid sent by the first blade passes through the inside of the rim and directly hits the rotary drive source.

[0011] Furthermore, the impeller of the present invention is characterized in that the rim is disposed with a gap in the axial and / or radial direction relative to the rotary drive source, and rotation of the first impeller generates a flow that flows into the rim and is discharged from the gap between the rim and the rotary drive source, and the rotary drive source is cooled by the flow.

[0012] In the impeller of the present invention, the rim surrounds the rotary drive source.

[0013] According to the present invention, the cooling effect of the rotary drive source can be improved with a simple structure.

[0014] Fig. 1 is a perspective view showing an impeller of the present embodiment; Fig. 2 shows the impeller of the present embodiment, (a) being a front view and (b) being a cross-sectional view; Fig. 3 is a schematic view showing an example of connection between the impeller of the present embodiment and a rotary drive source; Fig. 4 is a view showing an example of flow occurring around the rotary drive source; Fig. 5 is a view showing an example of arrangement of the impeller and the rotary drive source; Fig. 6 is a perspective view showing a flow sending device; Fig. 7 is a cross-sectional view showing the flow sending device;

[0015] An embodiment of the impeller of the present invention will be described below with reference to the drawings. Figure 1 is a perspective view of the impeller 1 of this embodiment, and Figure 2 shows the impeller 1 of this embodiment, with (a) being a front view and (b) being a cross-sectional view taken along line A-A. The impeller 1 comprises a rotation center body 2, a rim 4, a first blade 6, a second blade 8, etc.

[0016] The rotation center body 2 is connected to a rotation drive source 10 (see FIG. 3) and can rotate when rotational drive is transmitted from the rotation drive source 10. That is, the rotation center body 2 has a hole through which a rotation shaft 10a (see FIG. 3) of the rotation drive source 10 is inserted, an engaging portion that circumferentially engages with the rotation shaft 10a inserted through the hole, and the like, and is configured to rotate integrally with the rotation shaft 10a.

[0017] The rim 4 is generally annular and surrounds the rotation center body 2. The rim 4 is generally cylindrical, and its inner diameter is set to be equal to or greater than the outer dimensions of the rotary drive source 10. The axial length of the rim 4 can be set as appropriate. For example, the axial length of the rim 4 may be a length that can surround almost the entire rotary drive source 10, or a length that can surround a portion of the rotary drive source 10 (excluding the rotary shaft 10a). The axial length of the rim 4 may also be equal to or less than the length of the rotary shaft 10a, and may be a length that cannot surround the rotary drive source 10.

[0018] The first blades 6 are located between the rotation center body 2 and the rim 4 and face the rotary drive source 10 in the axial direction of the rotation center body 2. The first blades 6 extend in a substantially radial direction, with one end fixed to the outer circumferential surface of the rotation center body 2 and the other end fixed to the inner circumferential surface of the rim 4. A plurality of first blades 6 are arranged at substantially equal intervals along the rotation direction of the rotation center body 2.

[0019] The number of first blades 6 is eight as shown in FIG. 1 , but of course, is not limited to this and may be seven or less, or nine or more. Furthermore, the radial shape of the first blades 6 is not limited to a substantially radial shape and may be a radial curve, for example. Furthermore, the cross-sectional area of ​​the first blades 6 is set to be substantially uniform on the rotating body 2 side and the rim 4 side, but the cross-sectional area may differ between the radially inner side (rotating body 2 side) and the radially outer side (rim 4 side). For example, the cross-sectional area of ​​the first blades 6 may be set to gradually increase or decrease from the inner side to the outer side.

[0020] The second blades 8 are disposed on the outside of the rim 4. Specifically, the second blades 8 are fixed to the outer peripheral surface of the rim 4 and extend in a generally radial curve along the radial direction. The number of second blades 8 is six as shown in FIG. 1 etc., but is of course not limited to this and may be five or less, or seven or more. The cross-sectional shape and cross-sectional area of ​​the second blades 8 may be appropriately set, and may be different between the inside and outside in the radial direction. For example, the second blades 8 may be set so that the length along the circumferential direction is longer at the tip end on the radial outside than at the base end on the radial inside.

[0021] The impeller 1 in FIG. 1 has eight first blades 6 and six second blades 8, so that the number of first blades 6 is greater than the number of second blades 8. However, the numbers of first blades 6 and second blades 8 may of course be the same, or the number of second blades 8 may be greater than the number of first blades 6.

[0022] Figure 3 is a schematic diagram showing an example of a connection between the impeller 1 and the rotary drive source 10 of this embodiment. In Figure 3, the impeller 1 is shown in cross section B-B of Figure 2. The rotary drive source 10 connected to the impeller 1 is a so-called motor, and its rotating shaft 10a protruding outward is connected to the rotation center body 2 to rotate the impeller 1. For this purpose, the rotating shaft 10a of the rotary drive source 10 is inserted into and connected to the rotation center body 2.

[0023] 3 is disposed so as to be spaced apart in the axial direction from the main body 10b of the rotary drive source 10. That is, the axial length of the rim 4 is shorter than the rotation shaft 10a. As the impeller 1 rotates, it creates a flow that passes through the internal space of the rim 4 due to the first blades 6, and a flow that flows outside the rim 4 due to the second blades 8.

[0024] 4 is a diagram showing the flow direction of the fluid formed by the impeller 1. Of the flows generated by the rotation of the impeller 1, a flow 20 formed by the first blade 6 and passing through the internal space of the rim 4 cools the rotary drive source 10. That is, the flow 20 passes through the internal space of the rim 4, directly hits the rotary drive source 10, and flows around the rotary drive source 10. This flow 20 transfers heat generated in the rotary drive source 10, thereby cooling the rotary drive source 10.

[0025] As described above, according to the impeller 1 of this embodiment, the flow caused by the first blade 6 arranged opposite the rotary drive source 10 allows the fluid to be directly applied to the rotary drive source 10, thereby forcibly cooling the rotary drive source 10 and suppressing failures due to heat generation.

[0026] Furthermore, since there is no need for a separate air-cooling fan or the like used conventionally to air-cool the rotary drive source 10, the device in which the impeller 1 is mounted does not have to be made larger, and a compact design is possible while still providing high cooling performance to the rotary drive source 10.

[0027] The relative position of the impeller 1 with respect to the rotary drive source 10 is not limited to the position where the main body 10b is located outside the internal space of the rim 4 as described above. For example, as shown in FIG. 5(A), the main body 10b may be disposed so that a portion of the main body 10b enters the internal space of the rim 4. Alternatively, as shown in FIG. 5(B), the main body 10b may be disposed so that the entire main body 10b enters the internal space of the rim 4. In either case, the flow formed by the first blades 6 enters the internal space of the rim 4 and passes through the rim 4 via the gap between the inner peripheral surface of the rim 4 and the rotary drive source 10. As a result, the flow passing around the rotary drive source 10 forcibly cools the rotary drive source 10, thereby preventing breakdowns due to heat generation in the rotary drive source 10.

[0028] Next, a flow sending device 100 employing the impeller 1 of the present invention will be described. Fig. 6 is a perspective view of the flow sending device 100, and Fig. 7 is a cross-sectional view of the flow sending device 100. The flow sending device 100 comprises an upright, generally cylindrical housing 102, and fluid is drawn in from the outside via an inlet 104 at the top end of the housing 102, passes through attenuation means disposed within the housing 102, and is discharged from an outlet 106 at the bottom of the housing 102. Also disposed within the housing 102 between the inlet 104 and the outlet 106 is attenuation means for decomposing and / or inactivating and / or sterilizing toxic substances drawn in together with the fluid.

[0029] The elimination means includes an ultraviolet emitting unit 120 as a wave generating source that generates waves capable of eliminating toxic targets, and a substantially cylindrical reflector 130 that surrounds the ultraviolet light source 120. Inside the housing 102, the impeller 1 and rotary drive source 10 of the present invention are disposed downstream of the reflector 130 in the direction of fluid flow.

[0030] Here, the term "fluid" refers to a concept that includes gases, liquids, gels, slurries, powders, etc. Toxic targets include pathogenic microorganisms such as bacteria and viruses, as well as harmful molecules such as formaldehyde, sulfur dioxide gas, nitrous acid gas, odor components, volatile organic compounds (VOCs), and total organic carbon (TOC), and are objects that are toxic or harmful to at least the human body or the environment and that move with the fluid. Furthermore, "elimination of a toxic target" refers to the elimination or near-elimination of toxicity from the toxic target through decomposition, inactivation, sterilization, etc.

[0031] The suction section 104 has a structure capable of preventing leakage of ultraviolet light while reducing pressure loss within the flow sending device 100. Specifically, it has an inflatable body 110 arranged in the center in a plan view, an enclosing section 116 surrounding the outer circumferential surface of the inflatable body 110, and the like, and a space serving as an introduction path for the fluid is provided between the inflatable body 110 and the enclosing section 116.

[0032] The expandable body 110 has a shape that varies in outer diameter along the axial direction, such as a generally pot-shaped or generally bell-shaped shape. For example, the expandable body 110 has an expanded diameter portion 110a in the middle of the axial direction, where the diameter is the largest, and the diameter gradually decreases from the expanded diameter portion 110a to both ends.

[0033] The inflatable body 110 may have a tip 112 at one end upstream in the flow direction, which is generally pointed and has an obtuse or acute angle, and a base end 114 at the other end downstream in the flow direction, which is generally narrower in diameter than the expanded diameter portion 110a. That is, as shown in FIG. 7 , the expanded diameter portion 110a is generally conical from the tip 112 to the tip 112, and generally inverted truncated cone from the base 114 to the tip 112. The shape from the expanded diameter portion 110a to the tip 112 may be generally pyramidal, generally truncated conical, or generally truncated conical, or may have a spiral flow path on the outer surface. The shape from the expanded diameter portion 110a to the base 114 may also be generally inverted truncated cone or have a spiral flow path. Of course, the inflatable body 110 may have an overall generally pyramidal shape, such as a cone shape.

[0034] The surrounding portion 116 has a generally annular cross section and an inner diameter that varies along the axial direction. The surrounding portion 116 has a narrowed portion 118 near the opening, and an enlarged inner diameter portion 116a at an inner circumferential location radially opposite the enlarged diameter portion 110a.

[0035] The narrowed portion 118 has an inner diameter smaller than the outer diameter of the expanded diameter portion 110a but larger than the outer diameter near the tip 112. The inner diameter of the expanded inner diameter portion 116a is set so as to provide a predetermined gap relative to the expanded diameter portion 110a. Therefore, the inner diameter of the surrounding portion 116 is set so as to provide a gap of a predetermined size or larger between the surrounding portion 116 and the expansion body 110 so as not to impede the flow of fluid flowing into the suction portion 104. The cross-sectional area of ​​the gap extending circumferentially around the suction portion 104 can be set to be equal to or smaller than the cross-sectional area of ​​the internal space of the reflector 130 (described below). The position of the narrowed portion 118 is not limited to the vicinity of the open end, and can be set as appropriate as long as it does not impede the flow of fluid. For example, it can be located downstream of the expanded diameter portion 110a in the direction of fluid flow.

[0036] The gap between the expanded body 110 and the surrounding portion 116 configured as described above serves as an inlet passage through which the fluid can pass, and has a generally annular cross section. The inlet passage has at least a portion curved along the direction of the fluid flow. Specifically, as shown in FIG. 7 , a portion of the inlet passage defined between the expanded diameter portion 110a and the expanded inner diameter portion 116a can be curved in a generally C-shape along the direction of the fluid flow. The curved shape along the direction of the fluid flow is not limited to this, and may be a generally S-shape or a generally bellows-like shape that travels back and forth multiple times in the radial direction.

[0037] The discharge unit 106 is formed by a discharge port that opens at the bottom of the outer circumferential surface of the housing 102, and can discharge to the outside the fluid that has flowed down inside the housing 102. Note that the discharge unit 106 may be formed by a plurality of discharge ports arranged at approximately equal intervals along the circumferential direction, or may be formed by a single discharge port.

[0038] The reflector 130 has a hollow, generally cylindrical shape with both ends open, and has a UV-reflective reflective surface over substantially the entire inner circumferential surface. The UV light source 120 is disposed within the internal space of the reflector 130. UV light emitted from the UV light source 120 is highly reflected (repeatedly and continuously multiple times) by the inner circumferential surface. As a result, a UV region is formed with high-density, high-dose UV light. In this UV region, the UV dose can be amplified several tens of times or more compared to UV light directly emitted from the UV light source 120.

[0039] Such an inner peripheral surface may be made of, for example, a material having ultraviolet reflectivity (e.g., aluminum, etc.), or may be made by providing an ultraviolet reflecting reflective layer on the inside of the reflector 130. The reflective layer may be made of, for example, one or a combination of materials selected from high refractive index materials such as zirconium oxide (zirconia), tantalum pentoxide, titanium oxide, hafnium oxide (hafnia), yttrium oxide, zinc oxide, niobium pentoxide, chromium oxide, and aluminum oxide.

[0040] The method for forming the reflective layer is not particularly limited, and may be any suitable method, such as physical vapor deposition (PVD) methods such as vacuum deposition, ion plating, and sputtering, chemical vapor deposition (CVD) methods such as thermal CVD and plasma CVD, powder coating, solvent coating, printing, electroplating, electroless plating, electrodeposition coating, and water-based coating. For coating, an ultraviolet-reflective paint (e.g., a paint containing particulate silica (SiO), alumina (AlO), etc.) may be used.

[0041] The reflective layer can also be constructed by stacking high refractive index materials in layers, where each layer may be made of the same material, different materials, or different materials may be alternately stacked.

[0042] The ultraviolet light source 120 is, for example, a germicidal lamp, an ultraviolet lamp, an ultraviolet LED, or the like, and is arranged so as to irradiate ultraviolet light onto substantially the entire interior space of the reflector 130. The shape of the ultraviolet light source 120 may be set as appropriate, for example, a straight tube shape, a U-shaped tube shape, a spiral shape, a spherical shape, a balloon shape, or the like. A plurality of ultraviolet light sources 120 may be arranged, and the arrangement locations and number of the ultraviolet light sources 120 may be set as appropriate as long as they are capable of irradiating ultraviolet light onto at least the fluid flowing through the interior space of the reflector 130.

[0043] Furthermore, light-shielding portions 140 such as filters that block ultraviolet light can be disposed at or near both ends of the reflector 130. The light-shielding portions 140 have a structure that prevents the ultraviolet light emitted from the ultraviolet light source 120 from leaking out of the reflector 130 and allows the fluid to pass through reliably. The light-shielding portions 140 can be, for example, a structure (honeycomb core) formed by arranging polygonal three-dimensional figures such as squares and hexagons without any gaps.

[0044] The impeller 1 is positioned such that its rotation axis overlaps with an extension of the axis of the reflector 130. Furthermore, the rotary drive source 10 that rotates the impeller 1 is disposed facing the impeller 1 along the direction of flow caused by the impeller 1. The rotation of the impeller 1 can generate a flow within the flow sending device 1. That is, a flow can be formed in which the fluid flows into the flow sending device 100 through the suction portion 102 and is discharged from the discharge portion 106 via the ultraviolet space surrounded by the reflector 130.

[0045] As described above, among the fluid flows generated by the rotating impeller 1, the fluid that flows between the first blades 6 directly hits the rotary drive source 10 and flows around it, flowing downward to the discharge section 108. Therefore, heat generated in the rotary drive source 10 is transferred to the fluid flowing around the rotary drive source 10, forcibly cooling the rotary drive source 10, thereby keeping the temperature rise of the rotary drive source 10 below a certain level. This prevents malfunctions caused by heat generation in the rotary drive source 10. Furthermore, the impeller 1 has the first blade 6 and the second blade 8 in the radial direction, and fluid flows downstream of the first blade 6 and downstream of the second blade 8, respectively. Therefore, even if the flow of fluid is somewhat obstructed by the rotary drive source 10 located downstream of the first blade 6, sufficient space can be secured downstream of the first blade 8 for the fluid to flow in. Therefore, the inflow and outflow amounts of fluid that can be processed by the flow sending device 100 can be maintained.

[0046] REFERENCE SIGNS LIST 1... impeller, 2... rotation center body, 4... rim, 6... first blade, 8... second blade, 10... rotation drive source, 10a... rotating shaft, 100... flow sending device, 102... housing, 104... suction section, 106... exhaust section, 120... ultraviolet light source, 130... reflector

Claims

1. An impeller comprising: a rotating central body connected to a rotating shaft of a rotary drive source; a rim surrounding the rotating central body; a plurality of first blades arranged between the rotating central body and the rim; and a plurality of second blades arranged on the outside of the rim, wherein the inner diameter of the rim is equal to or larger than the outer dimension of the rotary drive source.

2. The impeller according to claim 1, wherein the first blade faces the rotary drive source.

3. The impeller according to claim 1, wherein the number of said first blades is equal to or greater than the number of said second blades.

4. The impeller according to claim 1, wherein the first blades extend approximately radially between the rotating body and the rim, with the axis of the rotating body as the center.

5. The impeller of claim 1, wherein the fluid conveyed by said first impeller passes through the inside of said rim and directly impinges on said rotary drive source.

6. The impeller according to claim 1, characterized in that the rim is disposed with a gap in the axial and / or radial direction relative to the rotary drive source, and the rotation of the first impeller generates a flow that flows into the rim and is discharged from the gap between the rim and the rotary drive source, and the rotary drive source is cooled by the flow.

7. The impeller of claim 1, wherein said rim surrounds said source of rotary drive.

Images