Blower

Abstract

This blower comprises: an impeller; a power supply unit having a positive terminal and a negative terminal or a ground terminal; a bell mouth that surrounds the outer peripheral side of the impeller and adjusts the flow of gas formed by the impeller, that is a conductor, and that is connected to the negative terminal or the ground terminal of the power supply unit; an electrode that is connected to the positive terminal of the power supply unit and has a positive potential, and is disposed within a first range in which ion wind based on corona discharge can be generated between the inner wall surface of the bell mouth and the outer peripheral end of the impeller on the gas suction side of the impeller.

Description

blower

[0001] The present disclosure relates to a blower equipped with a bellmouth.

[0002] Axial flow fans used in air conditioners, ventilation systems, and the like include an impeller with multiple blades attached to the outer peripheral surface of a hub, which serves as the center of rotation, and a bell mouth attached to the outer periphery of the impeller. The bell mouth is positioned opposite the outer peripheral end of the impeller to separate the gas intake side and the gas discharge side of the fan. The bell mouth is positioned with a gap between it and the impeller to prevent the outer peripheral end of the impeller from contacting the bell mouth. Fans are required to reduce blowing noise, but it is known that in the gap between the bell mouth and the outer peripheral end of the impeller, the pressure difference between the positive and negative pressure sides causes a reverse flow, resulting in leakage flow and the generation of vortices that cause noise. One technique for suppressing this leakage flow is to provide a stepped structure in the bell mouth (see, for example, Patent Document 1). The fan disclosed in Patent Document 1 includes multiple forward-blade-type blades and a bell mouth, and the bell mouth has a stepped shape with a throttle portion on the inner wall surface facing the blades.

[0003] JP 2010-236372 A

[0004] However, in the blower disclosed in Patent Document 1, the inner wall surface of the bell mouth is stepped, which causes pressure loss and turbulence in the airflow, leading to increased noise and reduced blowing performance.

[0005] The present disclosure is made to solve the above-mentioned problems, and aims to provide a blower that achieves low noise and improved blowing performance by reducing pressure loss and suppressing leakage flow.

[0006] The blower according to the present disclosure comprises an impeller, a power supply unit having a positive terminal and a negative terminal or a ground terminal, a bell mouth surrounding the outer periphery of the impeller and regulating the flow of gas formed by the impeller, the bell mouth being a conductor and connected to the negative terminal or the ground terminal of the power supply unit, and an electrode connected to the positive terminal of the power supply unit to be at a positive potential, the electrode being arranged within a first range on the gas suction side of the impeller, where an ionic wind based on corona discharge can be generated between the inner wall surface of the bell mouth and the outer periphery of the impeller.

[0007] The blower according to the present disclosure comprises an impeller, a power supply unit having a positive terminal and a negative terminal or a ground terminal, a bell mouth that surrounds the outer periphery of the impeller and regulates the flow of gas formed by the impeller, a discharge-side air guide part that is arranged downstream of the bell mouth so as to overlap at least a portion of the bell mouth in the radial direction and forms a discharge-side opposing space between itself and the discharge port of the bell mouth so as to guide the gas inside the bell mouth to the outside via the discharge-side opposing space, the discharge-side air guide part being a conductor and connected to the negative terminal or the ground terminal of the power supply unit, and a discharge-side electrode that is connected to the positive terminal of the power supply unit and has a positive potential, and is arranged on the gas discharge side of the impeller within a range where an ionic wind can be generated between the inner wall surface of the bell mouth and the discharge-side air guide part.

[0008] The blower of the present disclosure includes a power supply unit, a bell mouth that is a conductor and connected to the negative terminal or ground terminal of the power supply unit, and an electrode that is connected to the positive terminal of the power supply unit and has a positive potential, and is located within a first range on the gas intake side of the impeller between the inner wall surface of the bell mouth and the outer circumferential end of the impeller, where an ionic wind based on corona discharge can be generated. Alternatively, the blower of the present disclosure includes a power supply unit, a discharge-side air guide that is a conductor and connected to the negative terminal or ground terminal of the power supply unit, and a discharge-side electrode that is connected to the positive terminal of the power supply unit and has a positive potential, and is located within a range on the gas discharge side of the impeller, where an ionic wind can be generated between the inner wall surface of the bell mouth and the discharge-side air guide. This generates ionic wind that can suppress leakage flow while reducing pressure loss compared to conventional blowers, resulting in lower noise and improved blowing performance.

[0009] 1 is a perspective view showing a schematic configuration of a blower according to embodiment 1. FIG. 1 is a partial cross-sectional view showing a state in which the blower of FIG. 1 is connected to a power supply unit. FIG. 2 is a schematic diagram showing an example of electrode arrangement in the blower of FIG. 2. FIG. 3 is a schematic perspective view of an outdoor unit of an air conditioning apparatus, which is an example of an apparatus equipped with the blower according to embodiment 1. FIG. 4 is a schematic perspective view showing the internal structure of the outdoor unit of FIG. 4 from the rear side. FIG. 5 is a perspective view showing a schematic configuration of a blower according to embodiment 2. FIG. 6 is a partial cross-sectional view showing a state in which the blower of FIG. 6 is connected to a power supply unit. FIG. 7 is a schematic perspective view showing an example of an air flow in the blower of FIG. 7. FIG. 8 is a schematic perspective view showing an example of a method of supporting electrodes in the blower according to embodiment 2. FIG. 9 is a cross-sectional view showing the blower of FIG. 9. FIG. 10 is a schematic diagram showing a modified example of the suction side portion of the air guide mechanism in the blower according to embodiment 2. FIG. 11 is a schematic diagram showing the suction side portion of the air guide mechanism in the blower according to embodiment 3. FIG. 12 is a schematic diagram showing a first modified example of the suction side portion of the air guide mechanism shown in FIG. 13. FIG. 14 is a schematic diagram showing a second modified example of the suction side portion of the air guide mechanism shown in FIG. Fig. 16 is a schematic diagram of a third modified example of the suction side portion of the air guide mechanism shown in Fig. 12. Fig. 17 is a partial cross-sectional view showing a state in which a blower according to embodiment 4 is connected to a power supply unit. Fig. 18 is a partial enlarged view of the discharge side portion of the air guide mechanism shown in Fig. 16.

[0010] A blower according to an embodiment will be described below with reference to the drawings. Note that in the following drawings, including FIG. 1, the relative dimensional relationships and shapes of the components may differ from those in reality. In the following drawings, identical reference numerals denote identical or equivalent components, and this applies throughout the entire specification. To facilitate understanding, directional terms (e.g., "up," "down," "right," "left," "front," "rear," etc.) are used as appropriate, but these notations are merely for the sake of convenience and do not limit the arrangement or orientation of the device or components.

[0011] Embodiment 1 Fig. 1 is a perspective view showing a schematic configuration of a blower 100 according to embodiment 1. Fig. 2 is a partial cross-sectional view showing a state in which the blower 100 of Fig. 1 is connected to a power supply unit 8.

[0012] (Blower 100) First, a schematic configuration of the blower 100 will be described with reference to Figures 1 and 2. The blower 100 is an axial flow blower. The blower 100 includes an impeller 1 and an air guide mechanism surrounding the outer periphery of the impeller 1. The impeller 1 rotates about a rotation axis Ax and forms a gas flow. In the first embodiment, the air guide mechanism is a bell mouth 2 that surrounds the outer periphery of the impeller 1. A gap g through which gas flows is provided between the outer periphery end of the impeller 1 (hereinafter referred to as the impeller outer periphery end 10) and the inner periphery surface of the bell mouth 2 (hereinafter referred to as the bell mouth inner wall surface 20). The bell mouth 2 regulates the gas flow formed by the impeller 1.

[0013] 1 and 2, the upper side of the paper is the upstream side of the airflow relative to the impeller 1, i.e., the gas intake side, and the lower side of the paper is the downstream side of the airflow relative to the impeller 1, i.e., the gas discharge side. The Y-axis shown in Fig. 2 represents the radial direction relative to the rotation axis Ax of the impeller 1. In the following, the direction in which the rotation axis Ax extends may be referred to as the rotation axis direction.

[0014] The blower 100 also includes an annular electrode 6 arranged on the gas suction side of the impeller 1, and a power supply unit 8 to which the electrode 6 is connected. The electrode 6 is an annular line electrode. The power supply unit 8 has a positive terminal 81 and a ground terminal 83, and the electrode 6 is connected to the positive terminal 81 and serves as an electrode with a positive potential. The bell mouth 2 is made of a conductor and is connected to the ground terminal 83 of the power supply unit 8. The bell mouth 2 may also be connected to a negative terminal (not shown) of the power supply unit 8.

[0015] (Impeller 1 ) As shown in FIG. 1 , the impeller 1 includes a hub 12 provided on a rotation axis Ax, and a plurality of blades 11 connected to the hub 12 .

[0016] (Hub 12) The hub 12 is connected to a rotation shaft of a drive source (not shown) such as a motor, and is rotationally driven by the drive source, rotating about the rotation axis Ax. The hub 12 is cylindrical. Note that the shape of the hub 12 is not limited as long as it can be connected to the rotation shaft of the drive source as described above.

[0017] (Blades 11) The blades 11 are configured to extend radially outward from the hub 12. The blades 11 are spaced apart from one another in the circumferential direction. In the first embodiment, an example in which there are three blades 11 is illustrated, but the number of blades 11 is not limited to this.

[0018] The blade 11 has a leading edge 11a, a trailing edge 11b, an outer peripheral edge 11d, and an inner peripheral edge 11c. The leading edge 11a is located upstream of the airflow to be generated and is formed on the forward side of the blade 11 in the direction of rotation. In other words, the leading edge 11a is located forward of the trailing edge 11b in the direction of rotation. The trailing edge 11b is located downstream of the airflow to be generated and is formed on the backward side of the blade 11 in the direction of rotation. In other words, the trailing edge 11b is located rearward of the leading edge 11a in the direction of rotation. The impeller 1 has the leading edge 11a as the blade end facing the rotation direction of the impeller 1, and the trailing edge 11b as the blade end opposite the leading edge 11a in the direction of rotation.

[0019] The outer peripheral edge 11d is a portion that extends back and forth in an arc shape so as to connect the outermost periphery of the leading edge 11a and the outermost periphery of the trailing edge 11b. The outer peripheral edge 11d is located at the end of the impeller 1 in the radial direction (Y-axis direction). The outer peripheral edge 11d of the multiple blades 11 constitutes the impeller outer periphery 10. The inner peripheral edge 11c is a portion that extends back and forth in an arc shape between the innermost periphery of the leading edge 11a and the innermost periphery of the trailing edge 11b. The inner peripheral edge 11c of the blade 11 is connected to the hub 12.

[0020] The blades 11 are formed at a predetermined angle with respect to the rotation axis Ax. As the impeller 1 rotates, the blades 11 push against the gas present between them with their blade surfaces to transport the fluid. In this case, the surface of the blade where pressure increases by pushing against the fluid is referred to as the positive pressure surface 11s1, and the surface behind the positive pressure surface 11s1 where pressure decreases is referred to as the negative pressure surface 11s2. With respect to the direction of the airflow, the surface of the blade 11 on the upstream side (upper side of the drawing) is the negative pressure surface 11s2, and the surface on the downstream side (lower side of the drawing) is the positive pressure surface 11s1.

[0021] (Bell mouth 2) As shown in Fig. 1 , the bell mouth 2 has a cylindrical shape and is provided around the impeller 1. As shown in Fig. 2 , the bell mouth 2 partially overlaps the impeller 1 in the direction of the rotation axis. In Fig. 2 , the bell mouth 2 and impeller 1 are arranged so that a portion of the gas suction side of the impeller 1 protrudes from the upstream opening end 21 e of the bell mouth 2, and the downstream opening end 22 e of the bell mouth 2 is located downstream of the gas discharge side of the impeller 1.

[0022] The positional relationship between the bellmouth 2 and the impeller 1 is not limited to the above. The entire impeller 1 may be disposed between the upstream opening end 21 e and the downstream opening end 22 e of the bellmouth 2, or a portion of the impeller 1 may protrude from each of the upstream opening end 21 e and the downstream opening end 22 e of the bellmouth 2. Alternatively, a portion of the gas discharge side of the impeller 1 may protrude from the downstream opening end 22 e of the bellmouth 2, and the upstream opening end 21 e of the bellmouth 2 may be located upstream of the gas suction side of the impeller 1.

[0023] The bellmouth 2 has, from the upstream side to the downstream side in the direction of the rotation shaft, a suction port 21, a body 23, and a discharge port 22. The body 23 has a cylindrical shape with a substantially constant inner diameter. The suction port 21 is curved so that the inner diameter gradually decreases from the upstream opening end 21e toward the upstream end of the body 23. The discharge port 22 is curved so that the opening diameter gradually increases from the downstream end of the body 23 toward the downstream opening end 22e. In Figure 2, the cross section of the bellmouth inner wall surface 20 is arc-shaped at the suction port 21, linear at the body 23, and arc-shaped at the discharge port 22.

[0024] (Electrode 6) The electrode 6 has a circular shape centered on the rotation axis Ax of the impeller 1, and is provided around the periphery of the impeller 1. The electrode 6 is disposed on the upstream side of the bell mouth 2, spaced apart from the bell mouth inner wall surface 20 at the suction port portion 21.

[0025] However, leakage flow from the pressure surface 11s1 side to the suction surface 11s2 side of the blade 11, i.e., backflow from the discharge side to the suction side, may occur through the gap g between the impeller outer circumferential end 10 and the bellmouth inner wall surface 20. The leakage flow forms a vortex, causing pressure loss and also becoming a cause of noise.

[0026] Therefore, the blower 100 of the present disclosure is provided with the above-described electrode 6 and is configured to suppress leakage flow by the electrode 6. Specifically, the electrode 6 is disposed within a range (hereinafter also referred to as a first range) on the gas suction side of the impeller 1, where an ionic wind based on corona discharge can be generated between the bellmouth inner wall surface 20 and the impeller outer circumferential edge 10.

[0027] FIG. 3 is a schematic diagram showing an example of the arrangement of the electrodes 6 in the blower 100 of FIG. 2 . In FIG. 3 , the direction of the ionic wind is indicated by a dashed arrow. An example of the installation range (first range) of the electrodes 6 relative to the bellmouth 2 will be described with reference to FIG. 3 . Hereinafter, in a cross section including the rotation axis Ax and extending in the rotation axis direction, a line parallel to the rotation axis Ax that passes through the radially innermost point on the bellmouth inner wall surface 20 will be referred to as a first line L1, and a line perpendicular to the rotation axis Ax that passes through the suction-side most point on the bellmouth inner wall surface 20 will be referred to as a second line L2. As shown in FIG. 3 , in a cross section including the rotation axis Ax and extending in the rotation axis direction, the electrode 6 is arranged radially outward of the first line L1, upstream in the rotation axis direction (upper side of the drawing) of the second line L2, and within a circle C with a radius of 0.2D centered at the intersection P0 between the first line L1 and the second line L2, using the intersection P0 of the first line L1 and the second line L2 and the fan diameter D of the impeller 1. The fan diameter D of the impeller 1 refers to the maximum diameter of the impeller 1. In Fig. 3, the electrode 6 is disposed within the range enclosed by the first line L1, the second line L2, and the circle C, and is disposed at a position radially outwardly of the outer circumferential edge of the suction port portion 21 of the bell mouth 2 in the Y-axis direction.

[0028] (Actions and Effects) The potential difference between the positive electrode (electrode 6) and the bell mouth 2 generates a corona discharge between them, creating a localized ionized region. In the ionized region, the gas (hereinafter defined as air) is ionized and positively charged, and the positively charged particles move downstream toward the bell mouth 2. As the charged particles move downstream, they collide with neutral particles (air), creating a weak air current known as ionic wind. This downstream-flowing ionic wind suppresses leakage flow through the gap g from the discharge side to the suction side, resulting in reduced noise and improved airflow performance.

[0029] The location of electrode 6 is not limited to the range enclosed by first line L1, second line L2, and circle C. Electrode 6 may be located anywhere as long as it can generate an ionic wind that flows downstream along bellmouth inner wall surface 20 at suction port 21 toward the inner periphery.

[0030] Blower 100 can be applied to various devices, such as air conditioners and ventilation systems. Fig. 4 is a schematic perspective view of outdoor unit 200 of an air conditioner, which is an example of a device equipped with blower 100 according to embodiment 1. Fig. 5 is a schematic perspective view showing the internal structure of outdoor unit 200 of Fig. 4, viewed from the rear. In Fig. 5, the direction of airflow drawn into blower 100 from the rear side of outdoor unit 200 is indicated by an outline arrow.

[0031] 4 and 5, an intake port is provided in a side portion 202 and a rear portion (not shown) of the housing 201, and an exhaust port is provided in a front panel 203 of the housing 201. The blower 100 is installed inside the housing 201 with the intake side facing the rear side so that the exhaust port portion 22 of the bellmouth 2 is connected to the edge of the exhaust port of the front panel 203. The bellmouth 2 and the front panel 203 may be manufactured as a single unit.

[0032] The electrode 6 is disposed around the impeller 1 on the gas suction side of the bell mouth 2. The electrode 6 is fixed within the housing 201. Any method for fixing the electrode 6 may be used. In FIG. 5 , the electrode 6 is fixed to the front panel 203 while being insulated therefrom by a plurality of electrode support members 205, which are insulating members. The power supply unit 8 connected to the electrode 6 needs to be cooled, and is therefore desirably disposed in a well-ventilated location within the housing 201 (for example, a blower room). In FIG. 5 , the power supply unit 8 is attached to the side surface 202 where the air inlet is provided.

[0033] As described above, blower 100 according to embodiment 1 includes impeller 1, power supply unit 8 having positive terminal 81 and negative or ground terminal 83, and bell mouth 2 that surrounds the outer periphery of impeller 1 and regulates the flow of gas formed by impeller 1. Bell mouth 2 is a conductor and is connected to negative or ground terminal 83 of power supply unit 8. Blower 100 also includes electrode 6 that is connected to positive terminal 81 of power supply unit 8 to be at a positive potential, and is arranged within a first range on the gas suction side of impeller 1 where ionic wind can be generated based on corona discharge between bell mouth inner wall surface 20 and impeller outer periphery 10.

[0034] As described above, blower 100 comprises power supply unit 8, bell mouth 2 which is a conductor and connected to the negative terminal or ground terminal 83 of power supply unit 8, and electrode 6 which is connected to the positive terminal 81 of power supply unit 8 to be at a positive potential and which is arranged within a first range on the gas suction side of impeller 1 where ionic wind based on corona discharge can be generated between bell mouth inner wall surface 20 and impeller outer circumferential end 10. As a result, the generated ionic wind can suppress leakage flow while reducing pressure loss compared to conventional devices, thereby achieving the effects of lowering noise and improving air blowing performance.

[0035] Furthermore, in a cross section (see FIG. 3 ) that includes the rotation axis Ax of the impeller 1 and extends in the direction of the rotation axis, the first range is the range enclosed by the first line L1, the second line L2, and a circle C with a radius of 0.2D and centered at the intersection P0 of the first line L1 and the second line L2, where L1 is a line parallel to the rotation axis Ax that passes through the radially innermost point on the bell mouth inner wall surface 20, and D is a line perpendicular to the rotation axis Ax that passes through the suction-side point on the bell mouth inner wall surface 20, respectively. By arranging the electrode 6 within this predetermined first range, it is possible to more reliably generate an ionic wind that flows downstream through the gap g.

[0036] Embodiment 2. Fig. 6 is a perspective view showing a schematic configuration of a blower 100 according to embodiment 2. Fig. 7 is a partial cross-sectional view showing the blower 100 of Fig. 6 connected to a power supply unit 8. Fig. 8 is a schematic diagram showing an example of airflow in the blower 100 of Fig. 7. In Fig. 8, the direction of ionic wind is indicated by dashed arrows. Fig. 9 is a schematic perspective view showing an example of a method of supporting the electrode 6 in the blower 100 according to embodiment 2. Fig. 10 is a cross-sectional view showing a schematic view of the blower 100 of Fig. 9. The blower 100 according to embodiment 2 will be described below, focusing on the differences from embodiment 1.

[0037] 6 , in a blower 100 according to the second embodiment, the air guide mechanism is made up of a bell mouth 2 and a cylindrical suction-side air guide section 3 arranged upstream of the bell mouth 2. The configuration of the bell mouth 2 is the same as in the first embodiment.

[0038] As shown in Fig. 8, the suction-side air guide section 3 is disposed upstream of the bellmouth 2 so as to overlap at least a portion of the impeller 1 in the direction of the rotation axis, and at least a portion of the bellmouth 2 in the radial direction (Y-axis direction). In the example of Fig. 8, a portion of the downstream side of the suction-side air guide section 3 is disposed around a portion of the impeller 1 that protrudes upstream from the upstream opening end 21e of the bellmouth 2. In addition, in the example of Fig. 8, the suction-side air guide section 3 is curved so that the inner diameter gradually increases upstream, and has an arc-shaped cross section.

[0039] 8 , a suction-side opposing space SP1 is formed between the suction-side air guide section 3 and the bellmouth inner wall surface 20 of the suction port 21, which gradually increases in diameter toward the upstream open end 21e of the bellmouth 2. The downstream surface 32 of the suction-side air guide section 3, which faces the bellmouth inner wall surface 20 of the suction port 21, guides the gas in the suction-side opposing space SP1 into the bellmouth 2. The upstream surface 31 of the suction-side air guide section 3, which is upstream of the impeller 1, guides the gas on the outer periphery of the impeller 1 into the bellmouth 2.

[0040] The suction-side air guide section 3 may be an insulator or a conductor (for example, a metal electrode plate). If both the bell mouth 2 and the suction-side air guide section 3 are conductors, they are connected to the ground terminal 83 of the power supply unit 8 so that they are at the same potential, as shown in Figure 7.

[0041] As shown in Fig. 8 , electrode 6 is disposed upstream of bellmouth 2 in the rotational axis direction, spaced apart from bellmouth inner wall surface 20 at air inlet 21, and downstream of suction-side air guide section 3, spaced apart from downstream surface 32 of suction-side air guide section 3. Furthermore, electrode 6 is disposed within suction-side opposing space SP1 or on the outer periphery of suction-side opposing space SP1 in the radial direction (Y-axis direction). Note that, in the second embodiment, electrode 6 may also be disposed within the range enclosed by first line L1, second line L2, and circle C, as illustrated in Fig. 3 . However, electrode 6 is disposed downstream of suction-side air guide section 3 in the rotational axis direction.

[0042] 9 and 10 , the blower 100 is provided with a support member 5, which is an insulating member that supports the suction-side air guide section 3. The suction-side air guide section 3 is connected to the bellmouth 2 by the support member 5. In Fig. 10 , the support member 5 is formed in a substantially U-shape and connects the outer peripheral edge of the suction-side air guide section 3 to the downstream opening end 22e of the bellmouth 2 (i.e., the outer peripheral edge of the discharge port section 22).

[0043] The support members 5 are arranged at regular intervals in the circumferential direction (for example, every 30 degrees) and connect the suction-side air guide section 3 and the bellmouth 2. Note that in Figure 9, only two of the multiple support members 5 arranged at regular intervals in the circumferential direction are shown, and the others are omitted. Note that the shape, number, and arrangement of the support members 5 are not limited to the shape, number, and arrangement described above.

[0044] (Actions and Effects) As shown in Figure 8, a corona discharge occurs between the positive electrode (electrode 6) and the bell mouth 2 due to the potential difference between them. This creates a localized ionization region in the suction-side opposing space SP1. In the ionization region, gas (hereinafter, gas is defined as air) is ionized and positively charged, and the positively charged particles move downstream toward the bell mouth 2. As the charged particles move downstream, they collide with neutral particles (air), creating an ionic wind that flows downstream.

[0045] Furthermore, if the suction-side air guide 3 is a conductor, a corona discharge occurs between the positive electrode (electrode 6) and the suction-side air guide 3 due to the potential difference between them, thereby creating a localized ionized region in the suction-side opposing space SP1. In the ionized region, air is ionized and positively charged, and positively charged particles move toward the suction-side air guide 3. As the charged particles move toward the suction-side air guide 3, they collide with neutral particles (air), generating an ionic wind toward the suction-side air guide 3. This ionic wind flows along the downstream surface 32 of the suction-side air guide 3 and flows into the gap g together with the ionic wind generated on the bellmouth 2 side. This ionic wind suppresses leakage flow through the gap g from the discharge side to the suction side, resulting in reduced noise and improved airflow performance.

[0046] If the suction-side air guide section 3 is an insulator, corona discharge will not occur between the positive electrode (electrode 6) and the suction-side air guide section 3, but the suction-side air guide section 3 can suppress turbulence in the ionic wind flow that occurs between the electrode 6 and the bell mouth 2. This allows the ionic wind to flow efficiently downstream, and the stable ionic wind can enhance the effects of reducing noise and improving air blowing performance.

[0047] 11 is a schematic diagram showing a modified example of the suction-side portion of the air guide mechanism in the blower 100 according to the second embodiment. As shown in FIGS. 8 and 11 , the suction-side opposing space SP1 formed by the suction-side air guide section 3 and the bellmouth 2 narrows from the upstream side (i.e., the outer periphery) to the downstream side (i.e., the inner periphery) of the airflow in the suction-side opposing space SP1. That is, the suction-side opposing space SP1 is configured such that its cross-sectional area (i.e., the cross-sectional area through which the airflow passes) gradually decreases toward the downstream side. This configuration allows the airflow in the suction-side opposing space SP1 (e.g., the ionic wind) to be accelerated and flow into the gap g, thereby enabling a smaller voltage applied to the electrode 6 to generate an airflow with sufficient momentum to suppress backflow (leakage flow) through the gap g.

[0048] In the modified example shown in Fig. 11 , the cross section of the bellmouth inner wall surface 20 at the suction port 21 is arc-shaped, while the cross section of the upstream portion 33 of the suction-side air guide section 3 is linear and inclined from the rotation axis direction. That is, in the modified example shown in Fig. 11 , the difference between the width of the entrance (indicated by arrow A1) and the width of the exit (indicated by arrow A2) of the suction-side opposing space SP1 is greater than in the case of Fig. 8 . Therefore, in the modified example shown in Fig. 11 , the effect of accelerating the ionic wind or the effect of saving energy can be obtained compared to the case of Fig. 8 .

[0049] As described above, the blower 100 according to the second embodiment includes the suction-side air guide section 3 arranged upstream of the bellmouth 2. The suction-side air guide section 3 is arranged so that it at least partially overlaps the impeller 1 in the direction of the rotation axis, and at least partially overlaps the bellmouth 2 in the radial direction (Y-axis direction). The suction-side air guide section 3 forms a suction-side opposing space SP1 between itself and the suction port 21 of the bellmouth 2, and guides the gas in the suction-side opposing space SP1 into the bellmouth 2.

[0050] This allows the generated ionic wind to flow downstream efficiently, and the stable ionic wind can enhance the effects of reducing noise and improving air blowing performance.

[0051] The suction-side air guide section 3 is also configured so that the cross-sectional area of ​​the suction-side opposing space SP1 decreases downstream, thereby accelerating the airflow (ionic wind) in the suction-side opposing space SP1 and directing it into the gap g, thereby enabling, for example, a reduction in the voltage of the electrode 6 and achieving energy savings.

[0052] Embodiment 3. Figure 12 is a schematic diagram showing the suction side portion of the air guide mechanism in a blower 100 according to embodiment 3. The blower 100 according to embodiment 3 includes an suction side air guide section 3, similar to embodiment 2. In the blower 100 according to embodiment 3, the electrode 6 is different from that in embodiment 2. Below, the blower 100 according to embodiment 3 will be described, focusing on the differences from embodiment 2.

[0053] In the blower 100 according to the third embodiment, a first electrode 61 and a second electrode 62 are provided on the outer periphery of the impeller 1, upstream of the bell mouth 2 and downstream of the suction-side air guide section 3 in the direction of the rotation axis. The first electrode 61 and the second electrode 62 are each annular. The first electrode 61 and the second electrode 62 are each annular wire electrodes. The second electrode 62 is disposed downstream of the first electrode 61 in the gas flow in the suction-side opposing space SP1. In the example of FIG. 12 , the first electrode 61 is disposed radially (in the Y-axis direction) radially outward of the upstream opening end 21e of the bell mouth 2 (i.e., the outer periphery of the suction port 21), and the second electrode 62 is disposed radially (in the Y-axis direction) approximately at the center of the suction port 21 and downstream of the first electrode 61 in the direction of the rotation axis.

[0054] The first electrode 61 and the second electrode 62 are connected to, for example, the positive terminal 81 of the same power supply unit 8 and are at the same potential. Note that the first electrode 61 and the second electrode 62 may be at different potentials.

[0055] In this way, in the blower 100 according to the third embodiment, two types of flow can be created in the suction-side opposing space SP1 by providing not only the first electrode 61 but also the second electrode 62 downstream of the first electrode 61. This is because the positional relationships between the first electrode 61 and the second electrode 62 and each part of the suction port portion 21 of the bellmouth 2 are different, as shown by the solid arrows in Figure 12 .

[0056] In a configuration using multiple electrodes as described above, in order to generate an ion wind that flows downstream more efficiently, a portion of the suction port 21 of the bell mouth 2 may be insulated, and the portions of the suction port 21 that electrically interact with each electrode may be adjusted. Fig. 13 is a schematic diagram of a first modified example of the suction side portion of the air guide mechanism shown in Fig. 12. Fig. 14 is a schematic diagram of a second modified example of the suction side portion of the air guide mechanism shown in Fig. 12. Fig. 15 is a schematic diagram of a third modified example of the suction side portion of the air guide mechanism shown in Fig. 12.

[0057] The first, second, and third modified examples differ from one another in the portion of the suction port 21 of the bellmouth 2 that is insulated (hereinafter also referred to as the first insulating portion 25). In each of the first, second, and third modified examples, the portion of the suction port 21 that is insulated depends on the radial distance R2 from the rotation axis Ax of the second electrode 62 that is the downstream (i.e., innermost) of the first electrode 61 and the second electrode 62. Hereinafter, the range that is insulated will be expressed using the radial distance R2 from the rotation axis Ax of the second electrode 62, where Rin is the radial distance from the rotation axis Ax of the innermost end 25i of the first insulating portion 25 and Rout is the radial distance from the rotation axis Ax of the outermost end 25o of the first insulating portion 25.

[0058] 13 , in the first modified example, the range of insulation coating in the suction port portion 21 and the position of the second electrode 62 are set so that Rin < R2 < Rout. In addition, in the radial direction, the outermost edge 25o of the first insulating part 25 is located more inward than the outer edge of the suction port portion 21 (i.e., the upstream opening end 21e of the bellmouth 2). In other words, in the suction port portion 21 of the bellmouth 2, at least the portion corresponding to the cross-sectional center of the second electrode 62 in the radial direction is insulation coated, but the upstream opening end 21e is not insulation coated and the conductor is exposed.

[0059] By providing the first insulating section 25 and the second electrode 62 in this manner, a corona discharge is generated between the second electrode 62 and the suction-side air guide section 3, while the generation of corona discharge is suppressed between the second electrode 62 and the bell mouth 2. This makes it possible to prevent the ionic wind that is generated by the action of the outer peripheral first electrode 61 and flows downstream along the bell mouth 2 from being obstructed by the action of the second electrode 62.

[0060] Furthermore, in the first modified example, it is desirable that the second electrode 62 be located radially (in the Y-axis direction) more inward than the center position in the radial direction of the first insulating portion 25, i.e., more inward than (Rout+Rin) / 2. That is, in the first modified example, it is desirable that Rin<R2<(Rout+Rin) / 2.

[0061] 14 , in the second modified example, the range of insulation coating in the suction port portion 21 and the position of the second electrode 62 are set so that Rin < R2 < Rout. The outermost edge 25o of the first insulating part 25 is the outer circumferential edge of the suction port portion 21 (i.e., the upstream opening end 21e of the bellmouth 2). In other words, at least the portion of the suction port portion 21 of the bellmouth 2 that extends radially from a position corresponding to the cross-sectional center of the second electrode 62 to the upstream opening end 21e is insulation coated.

[0062] By providing the first insulating section 25 and the second electrode 62 in this manner, both the first electrode 61 and the second electrode 62 interact electrically with the suction-side air guide section 3 rather than with the bellmouth 2, and it is possible to generate an airflow (ionic wind) that flows downstream along the suction-side air guide section 3. Because this ionic wind flows along the downstream surface 32 of the suction-side air guide section 3, it has a smaller radially inward velocity component than the airflow that flows along the bellmouth 2, and leakage flow in the gap g can be more effectively suppressed.

[0063] 15 , in the third modified example, the range of the insulating coating in the suction port 21 and the position of the second electrode 62 are set so that R2<Rin and R2<Rout. In other words, in the suction port 21 of the bellmouth 2, the first insulating portion 25 is provided radially outward of a position corresponding to the center of the cross section of the second electrode 62.

[0064] By providing the first insulating portion 25 and the second electrode 62 in this manner, the second electrode 62 is made to interact electrically only with the portion on the trunk portion 23 side, without interacting electrically with the outer peripheral end side of the suction port portion 21 of the bellmouth 2. This prevents the generation of ions that flow out from the suction port portion 21 to the outer peripheral side.

[0065] 13 to 15, the radial position of the outermost end 25o of the first insulating portion 25 and the position of the second electrode 62 are set so that R2<Rout is satisfied. As a result, even when two electrodes (the first insulating portion 25 and the second electrode 62) are used, a flow can be generated from upstream to downstream without a reverse flow from downstream to upstream.

[0066] As described above, in blower 100 of embodiment 3, electrode 6 has first electrode 61 and second electrode 62 disposed downstream of first electrode 61. This makes it possible to create two types of flow in suction-side opposing space SP1, improving the versatility of blower 100.

[0067] Furthermore, a portion of the suction port portion 21 of the bell mouth 2 (first insulating portion 25) is covered with an insulating coating.

[0068] Furthermore, when the radial distance from the rotation axis Ax of the second electrode 62 is defined as R2 and the radial distance from the rotation axis Ax of the outermost end 25o of the part is defined as Rout, the part of the suction port 21 (first insulating part 25) and the second electrode 62 are arranged so that R2 < Rout. This makes it possible to generate a flow from upstream to downstream without a reverse flow from downstream to upstream, even when two electrodes (first insulating part 25 and second electrode 62) are used.

[0069] Fourth Embodiment Fig. 16 is a partial cross-sectional view showing a state in which a blower 100 according to a fourth embodiment is connected to a power supply unit 8. Fig. 17 is a partial enlarged view of the discharge side portion of the air guide mechanism shown in Fig. 16. The blower 100 according to the fourth embodiment differs from the second embodiment in that it includes a discharge side electrode 7 and a discharge side air guide section 4 provided downstream of the bell mouth 2. Below, the blower 100 according to the fourth embodiment will be described, focusing on the differences from the second embodiment.

[0070] 16 , in a blower 100 according to the fourth embodiment, the air guide mechanism is made up of a bell mouth 2, a suction-side air guide section 3 arranged upstream of the bell mouth 2, and a discharge-side air guide section 4 arranged downstream of the bell mouth 2. The bell mouth 2 and impeller 1 are arranged so that a portion of the impeller 1 protrudes from each of the upstream opening end 21 e and the downstream opening end 22 e of the bell mouth 2.

[0071] The suction-side air guide section 3 is disposed upstream of the bellmouth 2 so as to at least partially overlap the impeller 1 in the rotational axis direction and at least partially overlap the bellmouth 2 in the radial direction (Y-axis direction). A suction-side opposing space SP1 is formed between the suction-side air guide section 3 and a bellmouth inner wall surface 20 of the suction port 21 of the bellmouth 2, the diameter of which gradually increases toward the upstream opening end 21e. The electrode 6 is disposed upstream of the bellmouth 2 in the rotational axis direction, spaced apart from the bellmouth inner wall surface 20 of the suction port 21, and is disposed downstream of the suction-side air guide section 3, spaced apart from a downstream surface 32 of the suction-side air guide section 3. The electrode 6 is disposed within a first range on the gas suction side of the impeller 1 where an ionic wind based on corona discharge can be generated between the bellmouth inner wall surface 20 and the impeller outer circumferential end 10. In the fan 100 according to the fourth embodiment, the positional relationship between the suction port portion 21 of the bell mouth 2, the suction-side air guide portion 3, and the electrode 6 is the same as in the second embodiment.

[0072] The downstream side of the bell mouth 2 is coated with insulation. In the example of Figure 17, the lower half of the bell mouth 2 in the direction of the rotation axis, from the lower end (downstream opening end 22e) of the bell mouth 2 to the centre of the bell mouth 2, is coated with insulation. Hereinafter, the insulating coated part on the downstream side of the bell mouth 2 may be referred to as the second insulating part 26. The upstream end of the second insulating part 26 is provided in the body part 23 of the bell mouth 2. The part of the bell mouth 2 that is not coated with insulation and where the conductor is exposed is connected to the ground terminal 83 of the power supply unit 8.

[0073] The discharge-side air guide section 4 is disposed downstream of the bellmouth 2 so as to overlap at least partially with the impeller 1 in the direction of the rotation axis and at least partially with the bellmouth 2 in the radial direction (Y-axis direction). A discharge-side opposing space SP2 is formed between the discharge-side air guide section 4 and the bellmouth inner wall surface 20 of the discharge port section 22, which gradually increases in diameter toward the downstream opening end 22e of the bellmouth 2. An upstream surface 41 of the discharge-side air guide section 4 that faces the bellmouth inner wall surface 20 of the discharge port section 22 guides the gas in the discharge-side opposing space SP2 to the outside of the blower 100.

[0074] The discharge-side air guide section 4 is a conductor (for example, a metal electrode plate) formed in a cylindrical shape. The discharge-side air guide section 4 is connected to a ground terminal 83 of the power supply unit 8.

[0075] The discharge-side electrode 7 has a circular shape centered on the rotation axis Ax of the impeller 1 and is provided around the periphery of the impeller 1. The discharge-side electrode 7 is connected to the positive terminal 81 of the power supply unit 8. The discharge-side electrode 7 and the suction-side electrode 6 may be at the same or different potentials. The discharge-side electrode 7 is disposed downstream of the bell mouth 2 in the direction of the rotation axis, and upstream of the discharge-side air guide section 4, spaced apart from the upstream surface 41 of the discharge-side air guide section 4. The discharge-side electrode 7 interacts electrically with the discharge-side air guide section 4 to generate ionic wind.

[0076] The discharge-side electrode 7 is disposed within a second range where an ionic wind can be generated downstream between the bell-mouth inner wall surface 20 and the discharge-side air guide section 4 on the gas discharge side of the impeller 1. The reason why the second insulating section 26 is provided in the bell-mouth 2 is to prevent the generation of an ionic wind that flows backward upstream due to the electrical interaction between the discharge-side electrode 7 and the bell-mouth 2.

[0077] 16 and 17 , an example of the installation range (second range) of the discharge-side electrode 7 relative to the bellmouth 2 will be described. For example, within the discharge-side opposing space SP2, when the wetted length from the upstream end to the downstream end of the discharge-side air guide section 4 (i.e., the length of the curve) is L, the discharge-side electrode 7 is arranged within a range of 0.5L from the upstream end in the radial direction (Y-axis direction).

[0078] (Operation and Effect) The potential difference between the positive electrode (discharge-side electrode 7) and the discharge-side air guide 4 generates a corona discharge between them, creating a localized ionization region in the discharge-side facing space SP2. In the ionization region, gas (hereinafter, defined as air) is ionized and positively charged, and the positively charged particles move downstream toward the discharge-side air guide 4. As the charged particles move downstream, they collide with neutral particles (air), creating a weak airflow called ionic wind. This ionic wind is guided downstream and toward the outer periphery along the upstream surface 41 of the discharge-side air guide 4. This promotes the discharge of gas from the blower 100 to the outside through the discharge-side facing space SP2, suppressing backflow (leakage flow), thereby reducing noise and improving air blowing performance.

[0079] In the blower 100 according to embodiment 4, ionic wind is generated in both the suction side opposing space SP1 and the discharge side opposing space SP2, and the ionic wind flowing through the gap g from the suction side to the discharge side can be further stabilized, which is expected to result in even lower noise levels.

[0080] In the blower 100 according to the fourth embodiment, the electrode 6 on the upstream side of the bell mouth 2 and the suction-side air guide section 3 may be omitted. Even in this case, the discharge-side portion of the air guide mechanism and the discharge-side electrode 7 can still provide the effect of suppressing leakage flow compared to conventional blowers. In this case, the bell mouth 2 does not need to be a conductor and may be made of an insulator. The discharge-side portion of the air guide mechanism and the discharge-side electrode 7 in the fourth embodiment may also be applied to the first or third embodiment.

[0081] As described above, the blower 100 according to the fourth embodiment, like the first to third embodiments, includes an electrode 6 on the upstream side of the bellmouth 2. The blower 100 also includes a discharge-side air guide section 4. The discharge-side air guide section 4 is disposed downstream of the bellmouth 2 so as to overlap at least partially in the radial direction (Y-axis direction) with the bellmouth 2. The discharge-side air guide section 4 forms a discharge-side opposing space SP2 between itself and the discharge port 22 of the bellmouth 2, and guides the gas inside the bellmouth 2 to the outside via the discharge-side opposing space SP2. The discharge-side air guide section 4 is a conductor and is connected to the negative terminal or ground terminal 83 of the power supply unit 8. The blower 100 also includes a discharge-side electrode 7. The discharge-side electrode 7 is connected to the power supply unit 8 and set to a positive potential. The discharge-side electrode 7 is disposed within a second range on the gas discharge side of the impeller 1, where ionic wind can be generated between the bellmouth inner wall surface 20 and the discharge-side air guide section 4. The bell mouth 2 is coated with an insulating material on the downstream side (second insulating portion 26) including the discharge port portion 22.

[0082] This generates ionic wind in both the suction side opposing space SP1 and the discharge side opposing space SP2, making it possible to further stabilize the ionic wind flowing through the gap g from the suction side to the discharge side, and further reducing noise levels can be expected.

[0083] The second range is within the discharge-side opposing space SP2, and is a range from the upstream end to 0.5L in the radial direction (Y-axis direction) when the wetted length from the upstream end to the downstream end of the discharge-side air guide 4 is defined as L. This makes it possible to more reliably generate an ionic wind that flows downstream along the discharge-side air guide 4.

[0084] A blower 100 according to a fourth embodiment includes an impeller 1, a power supply unit 8, and a bellmouth 2 that surrounds the outer periphery of the impeller 1 and regulates the flow of gas formed by the impeller 1. The blower 100 is also provided with a discharge-side air guide section 4 that is disposed downstream of the bellmouth 2 so as to overlap at least partially in the radial direction (Y-axis direction) with the bellmouth 2, and that forms a discharge-side opposing space SP2 between itself and the discharge port 22 of the bellmouth 2 and guides gas within the bellmouth 2 to the outside via the discharge-side opposing space SP2. The discharge-side air guide section 4 is a conductor and is connected to the negative terminal or ground terminal 83 of the power supply unit 8. The blower 100 is also provided with a discharge-side electrode 7 that is connected to the power supply unit 8 and has a positive potential, and that is disposed on the gas discharge side of the impeller 1 between the bellmouth inner wall surface 20 and the discharge-side air guide section 4 within a range where an ionic wind can be generated downstream.

[0085] As a result, an ionic wind is generated in the discharge-side opposing space SP2, and the ionic wind is guided downstream and toward the outer periphery along the upstream surface 41 of the discharge-side air guide section 4. Therefore, the discharge of gas from the blower 100 to the outside via the discharge-side opposing space SP2 is promoted, suppressing leakage flow, which is a reverse flow, and achieving the effects of reducing noise and improving air blowing performance.

[0086] 1 impeller, 2 bell mouth, 3 suction side air guide portion, 4 discharge side air guide portion, 5 support member, 6 electrode, 7 discharge side electrode, 8 power supply unit, 10 impeller outer circumferential end, 11 blade, 11a leading edge portion, 11b trailing edge portion, 11c inner circumferential edge portion, 11d outer circumferential edge portion, 11s1 positive pressure surface, 11s2 negative pressure surface, 12 hub, 20 bell mouth inner wall surface, 21 suction port portion, 21e upstream opening end, 22 discharge port portion, 22e downstream opening end, 23 body portion, 25 first insulating portion, 25i innermost circumferential end, 25o outermost circumferential end, 26 second insulating portion, 31 surface, 32 surface, 33 upstream portion, 41 surface, 61 first electrode, 62 second electrode, 81 positive terminal, 83 ground terminal, 100 Blower, 200 outdoor unit, 201 housing, 202 side portion, 203 front panel, 205 electrode support member, A1 arrow, A2 arrow, Ax rotation axis, C circle, D fan diameter, L1 first line, L2 second line, P0 intersection point, R2 radial distance, SP1 suction side opposing space, SP2 discharge side opposing space, g gap.

Claims

1. A blower comprising: an impeller; a power supply unit having a positive terminal and a negative terminal or a ground terminal; a bell mouth that surrounds the outer periphery of the impeller and regulates the flow of gas formed by the impeller, the bell mouth being a conductor and connected to the negative terminal or the ground terminal of the power supply unit; and an electrode that is connected to the positive terminal of the power supply unit to be at a positive potential, and is arranged within a first range on the gas suction side of the impeller where an ionic wind based on corona discharge can be generated between the inner wall surface of the bell mouth and the outer periphery of the impeller.

2. The blower according to claim 1, wherein, in a cross section including the rotation axis of the impeller and extending in the direction of the rotation axis, the first range is defined as a line parallel to the rotation axis passing through the radially innermost point on the inner wall surface of the bell mouth, and a line perpendicular to the rotation axis passing through the suction-side point on the inner wall surface of the bell mouth is defined as a first line, and a fan diameter of the impeller is defined as D, and the first range is a range enclosed by the first line, the second line, and a circle with a radius of 0.2D centered at the intersection of the first line and the second line.

3. A blower as claimed in claim 1 or claim 2, further comprising an intake-side air guide section that is arranged upstream of the bell mouth so as to overlap at least partially with the impeller in the direction of the rotation axis and at least partially with the bell mouth in the radial direction, forming an intake-side opposing space between itself and the intake port of the bell mouth and guiding the gas in the intake-side opposing space into the bell mouth.

4. The blower according to claim 3, wherein the suction-side air guide section is provided so that the cross-sectional area of ​​the suction-side opposing space decreases toward the downstream side.

5. A blower according to claim 3 or claim 4, wherein the electrodes include a first electrode and a second electrode disposed downstream of the first electrode.

6. A blower according to claim 5, wherein a portion of the bell mouth at the intake port is insulated.

7. A blower as described in claim 6, wherein the portion of the suction port and the second electrode are arranged so that R2 < Rout, where R2 is the radial distance from the rotation axis of the second electrode and Rout is the radial distance from the rotation axis of the outermost peripheral end of the portion.

8. A blower according to any one of claims 1 to 7, comprising: a discharge-side air guide portion which is arranged downstream of the bell mouth so as to overlap at least a portion of the bell mouth in the radial direction, forming a discharge-side opposing space between it and the discharge port portion of the bell mouth and guiding the gas inside the bell mouth to the outside via the discharge-side opposing space, the discharge-side air guide portion being a conductor and connected to the negative terminal or the ground terminal of the power supply unit; and a discharge-side electrode which is connected to the power supply unit and has a positive potential, and is arranged within a second range on the gas discharge side of the impeller where ionic wind based on corona discharge can be generated between the inner wall surface of the bell mouth and the discharge-side air guide portion, wherein the downstream side including the discharge port portion of the bell mouth is insulated.

9. A blower as described in claim 8, wherein the second range is within the discharge side opposing space, and when the wetted length from the upstream end to the downstream end of the discharge side air guide section is defined as L, it is a range from the upstream end to 0.5L in the radial direction.

10. A blower comprising: an impeller; a power supply unit having a positive terminal and a negative terminal or a ground terminal; a bell mouth that surrounds the outer periphery of the impeller and regulates the flow of gas formed by the impeller; a discharge-side air guide part that is arranged downstream of the bell mouth so as to overlap at least a portion of the bell mouth in the radial direction, forming a discharge-side opposing space between it and a discharge port part of the bell mouth and guiding the gas inside the bell mouth to the outside through the discharge-side opposing space, the discharge-side air guide part being a conductor and connected to the negative terminal or the ground terminal of the power supply unit; and a discharge-side electrode that is connected to the positive terminal of the power supply unit and has a positive potential, and is arranged on the gas discharge side of the impeller within a range where an ionic wind can be generated between the inner wall surface of the bell mouth and the discharge-side air guide part.