blower

Abstract

To provide an air blower which can improve air blowing efficiency and can reduce noise.SOLUTION: A case 10 has a bell mouth 11 which forms a suction port 2 for sucking air. A fan 20 includes a main plate 21 provided rotatably around an axis in an inner side of the case 10, a plurality of blades 22 arranged around the axis and connected to the main plate 21, and a shroud 30 connected to a portion 23 on a side opposite to the main plate of the plurality of blades 22. A nozzle 60 is cylindrically formed and is provided in a region in a radial direction inner side of the bell mouth 11. A flow path partition member 70 is intermittently provided in a circumferential direction between the bell mouth 11 and the nozzle 60 and partitions a space between the nozzle 60 and the bell mouth 11 into a plurality of partition flow paths 73 through which air flows.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a blower. [Background technology]

[0002] The blower described in Patent Document 1 has a centrifugal fan disposed inside a case provided with a bellmouth that forms an air intake port. When the fan rotates, air is drawn in from inside the bellmouth, flows from the leading edge of the blades through the flow passages between the blades, and is blown out from an air outlet on the trailing edge of the blades. This blower has a shape in which the inner circumferential surface of the fan shroud and the inner circumferential surface of the bellmouth are substantially step-free, allowing air to be drawn smoothly into the fan from the bellmouth. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6634929 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the configuration described in Patent Document 1, when the pressure on the air outlet side of the fan becomes greater than the pressure on the air inlet side of the fan, the air blown out from the air outlet of the fan flows back toward the air inlet side of the fan through the gap between the shroud and the case. If the volume of this backflowing air increases, there is a concern that the blowing efficiency of the fan will decrease.

[0005] Furthermore, the air that flows back from the fan's air outlet to its air inlet contains a velocity component in the direction of the fan's rotation, so if this backflowing air containing that velocity component intersects with the main flow coming in from the air inlet and is sucked into the leading edge of the fan, it may generate noise.

[0006] In view of the above, the present invention aims to provide a blower that can improve blowing efficiency and reduce noise by reducing the amount of air that flows back from the air outlet side to the air inlet side of the fan. [Means for solving the problem]

[0007] To achieve the above object, according to the invention of claim 1, a blower includes a case (10), a fan (20), a nozzle (60), and a flow path partition member (70). The case has a bell mouth (11) that forms an inlet (2) for drawing in air. The fan has a main plate (21) that is rotatably provided around an axis (CL) inside the case, a plurality of blades (22) that are arranged around the axis and connected to the main plate, and a shroud (30) that is connected to portions (23) of the plurality of blades on the opposite side to the main plate. The nozzle is formed in a cylindrical shape and is provided in a region radially inside the bell mouth. The flow path partition members are provided intermittently in the circumferential direction between the bell mouth and the nozzle, and divide the space between the nozzle and the bell mouth into a plurality of partition flow paths (73) through which air flows. The flow path partition member is The number of partitions is increased and the thickness is thicker so that the pressure loss of air passing through the partition flow path increases compared to the number of partitions and thickness as viewed from the axial direction required to support the nozzle. According to a fourth aspect of the present invention, a blower includes a case (10), a fan (20), a nozzle (60), and a flow path partition member (70). The case has a bell mouth (11) that forms an air inlet (2) for drawing in air. The fan has a main plate (21) rotatably mounted around an axis (CL) inside the case, a plurality of blades (22) arranged around the axis and connected to the main plate, and a shroud (30) connected to portions (23) of the plurality of blades on the opposite side of the main plate. The nozzle is cylindrical and disposed in a region radially inside the bell mouth. The flow path partition members are disposed intermittently between the bell mouth and the nozzle in the circumferential direction and divide the space between the nozzle and the bell mouth into a plurality of partitioned flow paths (73) through which air flows. The flow path partition members are disposed in a net-like manner between the nozzle and the bell mouth so as to increase the pressure loss of air flowing between the nozzle and the bell mouth.

[0008] According to this, when the fan rotates, air drawn in from inside the nozzle flows from the leading edge side of the blades through the passages between the blades and is blown out from the air outlet on the trailing edge side of the blades. At this time, if the pressure loss in the passage downstream of the blower is large and the difference between the pressure on the fan's outlet side and the pressure on the suction port side increases as the fan's rotation speed increases, the volume of air flowing back from the fan's air outlet side to the suction port side through the gap between the shroud and the case (hereinafter referred to as "backflow air") increases. If the blower does not have a passage partition member, the backflow air may increase in speed and volume as it flows across the end of the nozzle opposite the main plate and into the inside of the nozzle. In contrast, in the invention of claim 1, passage partition members provided intermittently in the circumferential direction between the bell mouth and the nozzle divide the space between the nozzle and the bell mouth into multiple partition passages, thereby making it possible to increase the pressure loss of the backflow air passing through the multiple partition passages. Therefore, according to the invention of claim 1, the wind speed and volume of the backflow air that flows inside the nozzle across the end of the nozzle on the side opposite the main plate can be reduced, thereby improving the blowing efficiency of the blower.

[0009] Furthermore, as a result of research by the inventors, it was found that the backflow air that crosses over the end of the nozzle opposite the main plate and flows inside the nozzle has a large circumferential wind speed distribution, and this backflow air intersects with the main flow coming in from the suction port and flows toward the leading edge of the blade, increasing noise. In response to this, the invention of claim 1 makes it possible to reduce the circumferential wind speed distribution of the backflow air by increasing the pressure loss of the backflow air passing through multiple partition flow paths using a flow path partition member. Therefore, the invention of claim 1 makes it possible to reduce the noise of the blower.

[0010] According to the invention of claim 7, the blower includes a case (10), a fan (20), a nozzle (60), and a plurality of flow path partition members (70). The case has a bell mouth (11) that forms an inlet (2) for drawing in air. The fan has a main plate (21) that is rotatably provided around an axis (CL) inside the case, a plurality of blades (22) that are arranged around the axis and connected to the main plate, and a shroud (30) that is connected to portions (23) of the plurality of blades on the opposite side to the main plate. The nozzle is formed in a cylindrical shape and is provided in a region radially inside the bell mouth. The plurality of flow path partition members are provided between the bell mouth and the nozzle and divide the space between the nozzle and the bell mouth into a plurality of partition flow paths (73) through which air flows. This blower has areas where the spacing between the multiple flow path partition members is narrow and areas where the spacing between the multiple flow path partition members is wide, so that the wind speed of air flowing back through the space formed between the bell mouth and the nozzle from the air outlet side of the fan through the multiple partition flow paths to the suction port side inside the nozzle is uniform.

[0011] According to this, by arranging the locations where the gaps between the multiple flow path partition members are narrow in locations where the wind speed of the backflow air is high, it is possible to make the wind speed of the backflow air uniform in the circumferential direction between the nozzle and the bell mouth. Therefore, according to the invention of claim 7, the multiple flow path partition members can reduce the wind speed distribution in the circumferential direction of the backflow air across the nozzles, thereby reducing the noise of the blower.

[0012] Furthermore, in the invention of claim 7, by arranging the areas where the spacing between multiple flow path partition members is narrow in areas where the wind speed of the backflow air is high and increasing the pressure loss of the backflow air flowing through those areas, the volume of the backflow air can be reduced and the blowing efficiency of the blower can be improved.

[0013] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and the specific components described in the embodiments described below. [Brief explanation of the drawings]

[0014] [Figure 1]1 is a cross-sectional view of a blower according to a first embodiment, taken along an imaginary plane including an axis. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is an enlarged view of part III in FIG. 1, showing the air flow in face mode. [Figure 4] FIG. 3 is an enlarged view of a portion III in FIG. 1, showing the air flow in a foot mode or a defroster mode. [Figure 5] FIG. 4 is a view of a portion of a blower according to a second embodiment, the portion corresponding to FIG. 2. [Figure 6] FIG. 10 is a view of a portion of a blower according to a third embodiment, the portion corresponding to FIG. 2. [Figure 7] FIG. 10 is a view of a portion of a blower according to a fourth embodiment, the portion corresponding to FIG. 2. [Figure 8] FIG. 10 is a view of a portion of a blower according to a fifth embodiment, the portion corresponding to FIG. 2. [Figure 9] FIG. 3 is a view of a portion of the blower of the comparative example corresponding to FIG. 2, showing the air flow in the foot mode or the defroster mode. [Figure 10] FIG. 4 is a view corresponding to FIG. 3 in a blower of a comparative example, showing the air flow in face mode. [Figure 11] FIG. 4 is a view of a portion of the blower of the comparative example corresponding to FIG. 3, showing the air flow in the foot mode or the defroster mode. [Figure 12] FIG. 10 is a cross-sectional view of a blower according to a sixth embodiment, taken along an imaginary plane including the axis. [Figure 13] 13 is a cross-sectional view taken along line XIII-XIII in FIG. 12. [Figure 14] FIG. 13 is an enlarged view of a portion XVI in FIG. 12, showing the air flow in the face mode. [Figure 15] FIG. 16 is an enlarged view of a portion XVI in FIG. 12, showing the air flow in the foot mode or the defroster mode. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, identical or equivalent parts are designated by the same reference numerals, and their description will be omitted. Furthermore, the shapes of the components of the fan 1 shown in the drawings are shown schematically to facilitate understanding, and are not intended to limit the present invention.

[0016] (First embodiment) A first embodiment will be described with reference to the drawings. A blower 1 of the first embodiment is a centrifugal blower used in, for example, an air conditioner for a vehicle.

[0017] <Configuration of blower 1> 1 and 2, blower 1 includes a case 10, a fan 20, a drive unit 50, a nozzle 60, and a flow path partition member 70. Note that in FIG. 2, fan 20 and drive unit 50 are omitted for clarity. This also applies to FIGS. 5 to 9 and 13, which will be referred to in the embodiments and comparative examples described later.

[0018] In the following description, the axis CL of the fan 20 may be simply referred to as the "axis CL." The axis CL coincides with the center of rotation of the fan 20. In addition, the air intake 2 side of the blower 1 will be referred to as "one side in the axial direction," and the opposite side of the blower 1 from the air intake 2 will be referred to as "the other side in the axial direction." In the following description, the air intake 2 will be simply referred to as the intake 2.

[0019] The case 10 is a component that forms at least a part of the air passage of the vehicle air conditioner. Although not shown, the air passage of a vehicle air conditioner is generally provided with an air cooling device such as an evaporator, an air heating device such as a heater core or an electric heater, and a plurality of flow path switching doors. Therefore, in the vehicle air conditioner, the pressure loss of the air flowing through the air passage may change depending on the air conditioning mode.

[0020] The case 10 has a bell mouth 11 on the upstream side of the fan 20, which forms an intake port 2 for drawing in air. The bell mouth 11 has a curved shape in which the inner diameter gradually decreases from one side in the axial direction to the other. In addition, when viewed in a cross section obtained by cutting the bell mouth 11 along a plane including the axial center CL of the fan 20 (hereinafter referred to as a "longitudinal cross section"), the radially inner surface of the bell mouth 11 is formed in a substantially arc shape.

[0021] The case 10 has a front wall 12 that extends radially outward from a portion on one axial side of the bell mouth 11. The front wall 12 is formed in a planar shape that is approximately perpendicular to the axis CL of the fan 20. The front wall 12 may also be formed so as to be inclined with respect to the axis CL of the fan 20. The case 10 has an upstream case 13 that extends from a radially outer portion of the front wall 12 to one side in the axial direction.

[0022] The case 10 also has a cylindrical case portion 14 that extends cylindrically further toward the other axial direction from a portion on the other axial side of the bell mouth 11, and a case annular portion 15 that expands radially outward from a portion on the other axial side of the case cylindrical portion 14. The case 10 also has a downstream case 16 that extends toward the other axial direction from a radially outer portion of the case annular portion 15. Each portion of the case 10 may be made up of multiple members, or may be molded integrally.

[0023] The tubular case portion 14 is provided in a region radially outward of a tubular shroud portion 32 of the fan 20, which will be described later, with a predetermined gap therebetween. The annular case portion 15 is provided in a region on one side of the axial direction of the annular shroud portion 31 of the fan 20, which will be described later, with a predetermined gap therebetween. The tubular case portion 14 and the tubular shroud portion 32 are provided approximately parallel to each other, and the annular case portion 15 and the annular shroud portion 31 are also provided approximately parallel to each other.

[0024] The fan 20 is a centrifugal fan (specifically, a turbofan) and is rotatably provided inside the case 10. The fan 20 has a main plate 21, a plurality of blades 22, a shroud annular portion 31, and a shroud tubular portion 32. In the description of the first embodiment, the shroud annular portion 31 and the shroud tubular portion 32 may be collectively referred to as the shroud 30. The fan 20 is a closed fan in which the main plate 21, the plurality of blades 22, and the shroud 30 are integrally formed. The fan 20 is integrally formed, for example, by resin injection molding.

[0025] The main plate 21 is formed in a substantially disk shape and is disposed inside the case 10. The main plate 21 is inclined radially outward from the center toward the other side in the axial direction. In other words, the main plate 21 has a shape that convexly extends from the outer edge toward the center toward the suction port 2. A shaft 51 extending from the drive unit 50 is fixed to the center of the main plate 21. This enables the main plate 21 to rotate around the axis inside the case 10.

[0026] The plurality of blades 22 are arranged at predetermined intervals around the axis between the main plate 21 and the shroud 30. Each of the plurality of blades 22 has a portion 23 on one side in the axial direction (i.e., the portion 23 on the opposite side from the main plate) connected to the shroud 30, and a portion 24 on the other side in the axial direction connected to the main plate 21. This forms a flow path between adjacent blades 22 between the shroud 30 and the main plate 21. In the following description, this flow path will be referred to as an inter-blade flow path 25. When the fan 20 rotates, air drawn in from the suction port 2 passes through the inter-blade flow path 25 from the leading edge 26 side of the blade 22, and is blown out from an air outlet 28 formed on the trailing edge 27 side of the blade 22. Although not shown, the blades 22 extend rearward in the rotation direction of the fan 20 from the leading edge 26 to the trailing edge 27. That is, the fan 20 of the first embodiment is a turbofan.

[0027] The leading edge 26 of the blade 22 has an end 29 on one side in the axial direction connected to the shroud tubular portion 32. The leading edge 26 of the blade 22 is inclined radially inward from the end 29 on one side in the axial direction to an end 291 on the other side in the axial direction, and the end 291 on the other side in the axial direction is connected to the main plate 21 radially inward of the innermost diameter of the nozzle 60. In the following description, the leading edge 26 of the blade 22 may also be referred to as the blade leading edge 26.

[0028] In the first embodiment, the shroud 30 has a cylindrical shroud portion 32 formed on the suction port 2 side and an annular shroud portion 31 extending radially outward from a portion of the shroud portion 32 on the other axial side. The shroud portion 31 is an annular portion connected to one portion 23 of the plurality of blades 22 in the axial direction (i.e., the portion 23 of the plurality of blades 22 on the opposite side from the main plate). The shroud portion 32 is a portion of the shroud portion 31 extending cylindrically from a radially inner portion toward the opposite side from the main plate. The shroud portion 31 and the shroud portion 32 are formed continuously. The shroud portion 31 has a smoothly curved surface shape that is convex toward the inter-blade passage 25 in a longitudinal cross section. This prevents the air flowing through the inter-blade passage 25 from separating from the surface of the shroud 30 on the inter-blade passage 25 side, and instead flows along the surface of the shroud 30 on the inter-blade passage 25 side.

[0029] The drive unit 50 is an electric motor that outputs torque when energized. A shaft 51 protruding from the drive unit 50 is fixed to the main plate 21 of the fan 20. When the electric motor serving as the drive unit 50 is energized, the torque output by the drive unit 50 causes the shaft 51 and the fan 20 to rotate about their axes.

[0030] The nozzle 60 is formed in a cylindrical shape and is provided from the radially inner region of the bell mouth 11 to the radially inner region of the shroud cylindrical portion 32. The nozzle 60 is fixed to the case 10 by a flow path partition member 70 described later, and functions as a stator vane.

[0031] An end 61 of the nozzle 60 on the side opposite the main plate (i.e., one end of the nozzle 60 in the axial direction) protrudes further toward the side opposite the main plate (i.e., one side in the axial direction) than the front wall 12 of the case 10. The nozzle 60 has a shape that expands radially outward from the center toward the end 61 on the side opposite the main plate. The nozzle 60 also has a shape such that the outer diameter gradually decreases from the end 61 on the side opposite the main plate to the end 62 on the side opposite the main plate 21 (i.e., from one side in the axial direction to the other).

[0032] In addition, in a vertical cross-sectional view, the nozzle 60 has a thickness that gradually decreases from the central portion to an end 62 (i.e., the other end in the axial direction) of the nozzle 60, compared to the thickness from an end 61 on the side opposite the main plate (i.e., one end in the axial direction) to the central portion. The nozzle 60 has a so-called blade shape in which the axial length along the radially inner surface is longer than the axial length along the radially outer surface.

[0033] 1 and 2, a flow path partition member 70 is provided between the bell mouth 11 and the nozzle 60. A radially inner portion of the flow path partition member 70 is connected to the bell mouth 11, and a radially outer portion is connected to the nozzle 60. The flow path partition members 70 are provided intermittently in the circumferential direction between the bell mouth 11 and the nozzle 60, and divide the space between the nozzle 60 and the bell mouth 11 into a plurality of partition flow paths 73 through which air flows.

[0034] The flow path partition members 70 are preferably configured with at least twice the number (e.g., eight or more) of members required to support the nozzles 60 (e.g., two to four) so as to increase the pressure loss of air passing through the plurality of partition flow paths 73. Furthermore, the flow path partition members 70 are preferably configured with a number (e.g., eight or more) that can reduce the axial and circumferential air flows compared to the air flows in each partition flow path 73 when the number (e.g., two to four) required to support the nozzles 60 is used.

[0035] The blower 1 of the first embodiment illustrated in Fig. 2 has 20 flow path partition members 70. Increasing the number of flow path partition members 70 in this way makes it possible to increase the pressure loss of air passing through each partition flow path 73. It also makes it possible to reduce the axial and circumferential air flows in each partition flow path 73 and rectify the air flow in each partition flow path 73. However, the number of flow path partition members 70 is not limited to the number shown in Fig. 2 and can be set appropriately depending on the performance, specifications, etc. required of the blower 1.

[0036] Furthermore, it is preferable that each flow path partition member 70 has a large thickness when viewed from the axial direction in order to increase the pressure loss of air passing through the plurality of partition flow paths 73. However, taking into consideration the prevention of distortion during resin injection molding, the thickness of each flow path partition member 70 is preferably about 1.5 to 3.0 mm, and more preferably 2.0 to 2.5 mm.

[0037] Increasing the number of flow path partition members 70 and increasing the thickness of the flow path partition members 70 as viewed in the axial direction narrows the gap between adjacent flow path partition members 70 (i.e., the flow path cross-sectional area of ​​each partition flow path 73 as viewed in the axial direction). This makes it possible to increase the pressure loss of air passing through the partition flow paths 73. Furthermore, increasing the number of flow path partition members 70 and lengthening the axial length of the flow path partition members 70 increases the axial distance of each partition flow path 73. This makes it possible to increase the pressure loss of air passing through each partition flow path 73 and to improve the rectification effect of air flowing in the axial and circumferential directions through each partition flow path 73.

[0038] In the first embodiment, the flow path partition members 70 are provided radially between the nozzle 60 and the bell mouth 11. The flow path partition members 70 are provided around the entire circumference between the bell mouth 11 and the nozzle 60. The flow path partition members 70 are provided at uniform intervals in the circumferential direction between the bell mouth 11 and the nozzle 60. Note that uniform intervals in the circumferential direction mean uniform within a range that includes manufacturing tolerances, and in this specification, for example, if the difference in cross-sectional area between the multiple partition flow paths 73 formed by the flow path partition members 70 is within, for example, 5%, this is considered to be within the range of uniformity.

[0039] An end 71 of the flow path partition member 70 on the side opposite to the main plate is located closer to the main plate 21 than an end 61 of the nozzle 60 on the side opposite to the main plate. On the other hand, an end 72 of the flow path partition member 70 on the side opposite to the main plate is located closer to the side opposite to the main plate than an end 62 of the nozzle 60 on the side opposite to the main plate 21. Therefore, the flow path partition member 70 does not obstruct the mainstream flow that is sucked into the fan 20 from the flow path upstream of the nozzle 60 through the suction port 2 located radially inside the nozzle 60.

[0040] 3 and 4, in the following description of the first embodiment, the space between the nozzle 60 and the bell mouth 11 on one side of the partition passage 73 in the axial direction is referred to as a first passage 81. Furthermore, the space between the nozzle 60 and the case cylindrical portion 14 on the other side of the partition passage 73 in the axial direction is referred to as a second passage 82. Furthermore, the space between the nozzle 60 and the shroud cylindrical portion 32 is referred to as a third passage 83. Furthermore, the space between the shroud 30 (specifically, the shroud cylindrical portion 32 and the shroud annular portion 31) and the inner wall of the case 10 (specifically, the case cylindrical portion 14 and the case annular portion 15) is referred to as a gap passage 84.

[0041] <Operation of blower 1> Next, the flow of air when the fan 1 of this embodiment is operated will be described.

[0042] <Face mode> First, the air flow when the air conditioner is in face mode and blower 1 is operating will be described with reference to Fig. 3. Generally, when the air conditioner is in face mode, the pressure loss in the flow path downstream of blower 1 is smaller than in foot mode or defroster mode.

[0043] When the fan 20 rotates, air is drawn into the inter-blade flow passage 25 of the fan 20 from the radially inner region of the nozzle 60, as shown by arrow F1 in Figure 3. The air flow shown by arrow F1 is called the main flow. A part of this main flow flows along the radially inner surface of the nozzle 60.

[0044] At the same time, as shown by arrows F2 and F3, the air sucked into the fan 20 along the front wall 12 of the case 10 collides with the radially outer surface of the nozzle 60, flows along that surface through the first flow path 81 → partition flow path 73 → second flow path 82 → third flow path 83, and is sucked into the inter-blade flow path 25 from the blade leading edge 26 side.

[0045] Furthermore, when the fan 20 rotates, the pressure at the air outlet 28 of the fan 20 becomes higher than the pressure on the inlet 2 side of the fan 20. Therefore, as shown by arrows F4 and F5, air flows in the gap passage 84, flowing backward from the air outlet 28 side to the inlet 2 side. The air flowing backward through the gap passage 84 contains a velocity component in the rotation direction of the fan 20. The air flowing through the gap passage 84 shown by arrows F4 and F5 and the air flowing in from the first passage 81 shown by arrow F2 join together in the second passage 82, then flow through the third passage 83 shown by arrow F3, and are sucked into the inter-blade passage 25 from the blade leading edge 26 side together with the main flow.

[0046] Here, the pressure of the air flowing along the radially outer surface of the nozzle 60 is higher than the pressure of the mainstream air flowing into the fan 20 along the radially inner surface of the nozzle 60. Therefore, the pressure difference between the pressure in the first flow path 81, the partition flow path 73, and the second flow path 82 and the pressure on the air outlet 28 side of the fan 20 becomes smaller, and the amount of air flowing back through the gap flow path 84 from the air outlet 28 side of the fan 20 can be reduced.

[0047] Furthermore, when the air flowing through the first flow passage 81 and the air that has flowed backward through the gap flow passage 84 join together in the second flow passage 82, the velocity component of the joined air in the rotational direction of the fan 20 decreases. Therefore, the angle of intersection between the air blown out from the third flow passage 83 toward the blade leading edge 26 and the main flow decreases, making it possible to reduce noise.

[0048] <Foot mode or defroster mode> Next, the air flow when the air conditioner is in foot mode or defroster mode and the blower 1 is operated will be described with reference to FIG.

[0049] As the fan 20 rotates, the main flow is drawn into the inter-blade passage 25 from the leading edge 26 of the fan 20 along the radially inner surface of the nozzle 60, as indicated by arrow F1 in FIG. 4 . Generally, when an air conditioner is in foot mode or defroster mode, the pressure loss in the passage downstream of the blower 1 is greater than in face mode. Therefore, as the rotation speed of the fan 20 increases, the difference in pressure between the air outlet 28 side and the air inlet 2 side of the fan 20 becomes greater than the pressure difference in face mode. As a result, when the velocity and volume of air flowing back through the gap passage 84 increase, the backflow air attempts to flow from the second passage 82 through the partition passage 73 and the first passage 81, straddle the end 61 of the nozzle 60 on the anti-main-plate side, and into the inside of the nozzle 60, as indicated by dashed arrow F6 in FIG. 4 . In contrast, in the first embodiment, the space between the nozzle 60 and the bell mouth 11 is divided into multiple partitioned flow paths 73 by the flow path partition member 70, so the pressure loss of the backflow air passing through the partitioned flow paths 73 increases, and the wind speed and volume of the backflow air are reduced.

[0050] Furthermore, research by the inventors has revealed that the backflow air that attempts to flow inside the nozzle 60 across the end 61 of the nozzle 60 on the side opposite to the main plate has a large circumferential wind speed distribution. In contrast, in the first embodiment, the space between the nozzle 60 and the bellmouth 11 is partitioned into a plurality of partition flow paths 73 by the flow path partition member 70, so that the pressure loss of the backflow air passing through the partition flow paths 73 increases and the circumferential wind speed distribution of the backflow air is reduced.

[0051] <Comparative Example> Here, for comparison with the fan 1 of the first embodiment described above, a comparative fan 100 will be described with reference to Figures 9 to 11. Note that this comparative fan 100 was created by the applicant and is not prior art.

[0052] 9, the blower 100 of the comparative example is provided with the number of ribs 700 (for example, four) required to support the nozzle 60 between the bell mouth 11 and the nozzle 60. The effect of these ribs 700 as flow path resistance for the backflow air is so small that it can be ignored.

[0053] <Face mode in comparison example> Fig. 10 shows the airflow in blower 100 of the comparative example when the air conditioner is in face mode. As indicated by arrows F1 to F5 in Fig. 10, the airflow in blower 100 of the comparative example when the air conditioner is in face mode and blower 1 is operating is the same as that in blower 1 of the first embodiment. Therefore, in blower 100 of the comparative example, when the air conditioner is in face mode, the amount of backflow air is reduced, improving blowing efficiency and reducing noise.

[0054] <Foot mode or defroster mode in comparative example> Next, FIG. 11 shows the airflow in the blower 100 of the comparative example when the air conditioner is in foot mode or defroster mode. When the fan 20 rotates, the main flow is drawn into the inter-blade passage 25 from the leading edge 26 of the fan 20 along the radially inner surface of the nozzle 60, as indicated by arrow F1 in FIG. 11 . As described above, when the air conditioner is in foot mode or defroster mode, the pressure loss in the passage downstream of the blower 100 is greater than in face mode. Therefore, as the rotation speed of the fan 20 increases, the difference in pressure between the air outlet 28 side and the air inlet 2 side of the fan 20 becomes greater than the pressure difference in face mode. As a result, when the wind speed and volume of air flowing back through the gap passage 84 increase, the backflow air flows over the end 61 of the nozzle 60 on the opposite side to the main plate and into the inside of the nozzle 60, as indicated by arrow F7 in FIG. 11 .

[0055] Here, as shown by arrows F8 to F13 in FIG. 9 , research by the inventors has revealed that the backflow air that crosses over the end 61 of the nozzle 60 on the side opposite the main plate and flows inside the nozzle 60 (hereinafter referred to as "backflow air crossing the nozzle 60") has a large circumferential wind speed distribution. That is, the multiple arrows F8 to F13 shown in FIG. 9 indicate locations where the wind speed of the backflow air crossing the nozzle 60 is large. On the other hand, in the regions between the arrows F8 to F13 shown in FIG. 9 , the wind speed of the backflow air crossing the nozzle 60 is small. As such, with the blower 100 of the comparative example, when the air conditioner is in foot mode or defroster mode, the backflow air crossing the nozzle 60, while having a large circumferential wind speed distribution, merges with the main flow and flows toward the leading edge 26 of the blade 22, which may increase noise.

[0056] <Operations and Effects of the Fan 1 of the First Embodiment> In comparison with the fan 100 of the comparative example, the fan 1 of the first embodiment has the following advantages. (1) The blower 1 of the first embodiment is equipped with flow path partition members 70 that are provided intermittently in the circumferential direction between the bell mouth 11 and the nozzle 60. These flow path partition members 70 divide the space between the nozzle 60 and the bell mouth 11 into a plurality of partition flow paths 73 through which air flows. By dividing the space between the nozzle 60 and the bell mouth 11 into a plurality of partition flow paths 73 using the flow path partition members 70, it is possible to increase the pressure loss of backflow air passing through the plurality of partition flow paths 73. Therefore, this blower 1 can reduce the wind speed and volume of backflow air and improve blowing efficiency.

[0057] Furthermore, as a result of research by the inventors as described above, it was found that the backflow air that crosses over the nozzle 60 has a large circumferential wind speed distribution, and that this backflow air, while maintaining its wind speed distribution, intersects with the main flow and flows toward the leading edge 26 of the blade 22, increasing noise. In contrast, the blower 1 of the first embodiment can reduce the circumferential wind speed distribution of the backflow air that crosses over the nozzle 60 by using the flow path partition member 70 to increase the pressure loss of the backflow air passing through the partition flow path 73. Therefore, this blower 1 can reduce the noise generated when the backflow air flows toward the leading edge 26 of the blade.

[0058] (2) In the first embodiment, the flow path partition members 70 are provided radially between the nozzle 60 and the bell mouth 11 so as to increase the pressure loss of the air flowing through the plurality of partition flow paths 73. This illustrates a specific arrangement of the plurality of flow path partition members 70.

[0059] (3) In the first embodiment, the end 71 of the flow path partition member 70 on the side opposite to the main plate is located closer to the main plate 21 than the end 61 of the nozzle 60 on the side opposite to the main plate. In addition, the end 72 of the flow path partition member 70 on the side opposite to the main plate is located closer to the side opposite to the main plate than the end 62 of the nozzle 60 on the side opposite to the main plate 21. With this, the flow path partition member 70 does not obstruct the main flow that passes from the flow path upstream of the nozzle 60 to the radially inner side of the nozzle 60 and is sucked into the fan 20 .

[0060] (4) In the first embodiment, the flow path partition members 70 are provided between the bell mouth 11 and the nozzle 60 at uniform intervals in the circumferential direction. This makes it possible to reduce the wind speed and volume of the backflow air flowing through the partition flow passage 73 by uniformly increasing the pressure loss of the backflow air passing through the partition flow passage 73 in the circumferential direction, thereby reducing the wind speed distribution. Furthermore, even if the position of the circumferential wind speed distribution of the backflow air across the nozzle 60 changes due to the operating conditions of the blower 1 or the like, it is possible to reduce the wind speed distribution.

[0061] (5) In the first embodiment, the flow path partition member 70 is provided between the bell mouth 11 and the nozzle 60 over the entire circumference. This increases the pressure loss of the backflow air passing through the partition flow path 73 over the entire circumference, thereby reducing the wind speed and volume of the backflow air flowing through the partition flow path 73, thereby making it possible to reduce the wind speed distribution. Also, even if the position of the circumferential wind speed distribution of the backflow air across the nozzle 60 changes due to the operating conditions of the blower 1 or the like, it is possible to reduce the wind speed distribution.

[0062] (6) In the first embodiment, the fan 20 is a turbofan in which the blades 22 extend rearward in the direction of rotation from the leading edge 26 to the trailing edge 27. According to this, among centrifugal fans, turbofans have the characteristic that the volume of backflow air tends to increase due to the large pressure difference between the intake port 2 and the air outlet 28. Even in blower 1 equipped with a turbofan having such characteristics, it is possible to achieve the effects of improving blowing efficiency and reducing noise.

[0063] (7) In the first embodiment, the number of flow path partition members 70 is at least twice the number required to support the nozzles 60 . According to this, by increasing the number of flow path partition members 70, the flow path cross-sectional area of ​​each partition flow path 73 becomes smaller, and it is possible to increase the pressure loss of the backflow air passing through the partition flow paths 73. Therefore, it is possible to reduce the air volume of the backflow air and reduce the circumferential wind speed distribution of the backflow air.

[0064] (Second to fifth embodiments) The second to fifth embodiments are different from the first embodiment in the configuration of the flow path partition member 70, but are otherwise similar to the first embodiment, so only the parts that differ from the first embodiment will be described.

[0065] (Second embodiment) 5, in the second embodiment, the flow path partition member 70 provided between the bell mouth 11 and the nozzle 60 is configured in a mesh-like shape. The mesh of the mesh-like flow path forming member forms a plurality of partition flow paths 73. The mesh-like flow path partition member 70 is provided all around the circumference between the bell mouth 11 and the nozzle 60 so as to increase the pressure loss of air passing through the plurality of partition flow paths 73.

[0066] It is possible to arbitrarily set the thickness of the mesh-like flow path forming member, the flow path cross-sectional area of ​​the plurality of partition flow paths 73, and the flow path length in the axial direction of the plurality of partition flow paths 73. Specifically, although the shape of the plurality of partition flow paths 73 is rectangular in Fig. 5, the shape of the plurality of partition flow paths 73 is not limited to this, and the shape of the plurality of partition flow paths 73 can be arbitrarily set, for example, to a circle, an ellipse, a polygon, or a combination thereof.

[0067] The mesh-like flow path partition member 70 provided in the blower 1 of the second embodiment described above also increases the pressure loss of the backflow air passing through the plurality of partition flow paths 73, thereby reducing the wind speed and volume of the backflow air and making it possible to reduce the circumferential wind speed distribution of the backflow air across the nozzle 60. Therefore, the blower 1 of the second embodiment can also improve the blowing efficiency and reduce noise.

[0068] (Third embodiment) As shown in FIG. 6 , in the third embodiment, the flow path partition members 70 are provided only within a predetermined angular range that is set at multiple locations in the circumferential direction between the bell mouth 11 and the nozzle 60. In FIG. 6 , the predetermined angular ranges in which the flow path partition members 70 are provided are indicated by arrows R1 to R3. In the third embodiment, three predetermined angular ranges are set. The predetermined angular ranges in which the flow path partition members 70 are provided are set at locations where the wind speed of backflow air crossing the nozzle 60 would be high if the flow path partition member 70 were not provided. These locations can be set through experiments, simulations, or the like. In this way, the blower 1 of the third embodiment has locations where the spacing between the multiple flow path partition members 70 is narrow and locations where the spacing between the multiple flow path partition members 70 is wide, so that the wind speed of the backflow air crossing the nozzle 60 is uniform.

[0069] The blower 1 of the third embodiment described above can uniformize the wind speed of the backflow air in the circumferential direction between the nozzle 60 and the bell mouth 11 by arranging the areas where the gaps between the multiple flow path partition members 70 are narrow in areas where the wind speed of the backflow air is high. This reduces the circumferential wind speed distribution of the backflow air across the nozzle 60, and can reduce the wind speed and volume of the backflow air. Furthermore, the third embodiment can be configured so that no more flow path partition members 70 than necessary are provided.

[0070] (Fourth embodiment) 7, in the fourth embodiment, the flow path partition members 70 are provided at uneven intervals in the circumferential direction between the bell mouth 11 and the nozzle 60. Note that uneven intervals in the circumferential direction mean that if they were arranged uniformly in the circumferential direction, the unevenness would be such that it does not include manufacturing tolerances. For example, if the difference in cross-sectional area between the plurality of partition flow paths 73 formed by the plurality of flow path partition members 70 is greater than 5%, it can be said that the unevenness is present.

[0071] The blower 1 of the fourth embodiment can increase the pressure loss of the backflow air passing through the plurality of partition flow paths 73 and make the wind speed of the backflow air uniform. That is, it is possible to reduce the circumferential wind speed distribution of the backflow air across the nozzle 60 and reduce the wind speed and volume of the backflow air.

[0072] (Fifth embodiment) The fifth embodiment is a modification of the third embodiment. As shown in Fig. 8, in the fifth embodiment, the flow path partition member 70 is provided only in a predetermined angular range set at six locations in the circumferential direction between the bell mouth 11 and the nozzle 60. In Fig. 8, the predetermined angular range in which the flow path partition member 70 is provided is indicated by arrows R1 to R6. The predetermined angular range in which the flow path partition member 70 is provided is set to a location where the wind speed of the backflow air crossing the nozzle 60 would be high if the flow path partition member 70 were not provided. This location can be set by experiment, simulation, or the like. In other words, the predetermined angular range in which the flow path partition member 70 is provided is not limited to the six locations shown in Fig. 8, but can be set arbitrarily.

[0073] In this way, the blower 1 of the fifth embodiment also has areas where the spacing between the plurality of flow path partition members 70 is narrow and areas where the spacing between the plurality of flow path partition members 70 is wide, so that the wind speed of the backflow air across the nozzles 60 is uniform. The blower 1 of the fifth embodiment can also achieve the same effects as the third embodiment and the like.

[0074] (Sixth embodiment) The sixth embodiment will be described with reference to the drawings. The sixth embodiment is similar to the first embodiment except that it does not have the shroud tubular portion 32. Therefore, only the differences from the first embodiment will be described.

[0075] <Configuration of blower 1> As shown in FIG. 12, the blower 1 of the sixth embodiment also includes a case 10, a fan 20, a drive unit 50, a nozzle 60, a flow path partition member 70, and the like. The fan 20 has a main plate 21, a plurality of blades 22, and a shroud 30. In the sixth embodiment, the shroud 30 has a shroud annular portion 31 connected to portions 23 of the plurality of blades 22 on the opposite side to the main plate. However, in the sixth embodiment, the shroud 30 does not have a portion that extends cylindrically from a radially inner portion of the shroud annular portion 31 toward the opposite side to the main plate (i.e., the shroud cylindrical portion 32 described in the first embodiment). The nozzle 60 is formed in a cylindrical shape and is provided from the radially inner region of the bell mouth 11 to the radially inner region of the case cylindrical portion 14. Other configurations of the blower 1 of the sixth embodiment are substantially the same as those described in the first embodiment.

[0076] 12 and 13 , a plurality of flow path partition members 70 are provided between the bell mouth 11 and the nozzle 60. The plurality of flow path partition members 70 are provided intermittently in the circumferential direction between the bell mouth 11 and the nozzle 60, and divide the space between the nozzle 60 and the bell mouth 11 into a plurality of partition flow paths 73 through which air flows. The number, thickness, etc. of the plurality of flow path partition members 70 are the same as those described in the first embodiment. That is, the number, thickness, etc. of the plurality of flow path partition members 70 are set for the purpose of increasing the pressure loss of air passing through each partition flow path 73, reducing the axial and circumferential air flow in each partition flow path 73, and rectifying the air flow in each partition flow path 73.

[0077] 13 , in the sixth embodiment, a plurality of flow path partition members 70 are provided radially between the nozzle 60 and the bell mouth 11. The plurality of flow path partition members 70 are also provided around the entire circumference between the bell mouth 11 and the nozzle 60. The plurality of flow path partition members 70 are also provided at uniform intervals in the circumferential direction between the bell mouth 11 and the nozzle 60. However, the number, shape, arrangement, etc. of the flow path partition members 70 are not limited to those shown in FIG. 13, and the configurations described in the second to fifth embodiments can also be applied.

[0078] <Operation of blower 1> Next, the flow of air when the fan 1 of this embodiment is operated will be described with reference to FIGS.

[0079] 14 and 15 , in the following description of the sixth embodiment, the space between the nozzle 60 and the bell mouth 11 on one side of the partition passage 73 in the axial direction is called a first passage 81. Furthermore, the space between the nozzle 60 and the cylindrical case portion 14 on the other side of the partition passage 73 in the axial direction is called a second passage 82. Furthermore, the space between the shroud 30 and the inner wall of the case 10 is called a gap passage 84.

[0080] <Face mode> First, the air flow when the air conditioner is in face mode and blower 1 is operating will be described with reference to Fig. 14. Generally, when the air conditioner is in face mode, the pressure loss in the flow path downstream of blower 1 is smaller than in foot mode or defroster mode.

[0081] When the fan 20 rotates, air is drawn into the inter-blade flow passage 25 of the fan 20 from the radially inner region of the nozzle 60, as shown by arrow F1 in Figure 14. The air flow shown by arrow F1 is called the main flow. Part of this main flow flows along the radially inner surface of the nozzle 60.

[0082] At the same time, as shown by arrows F2 and F3, the air sucked into the fan 20 along the front wall 12 of the case 10 collides with the radially outer surface of the nozzle 60, flows along that surface through the first flow path 81 → partition flow path 73 → second flow path 82, and is sucked into the inter-blade flow path 25 from the blade leading edge 26 side.

[0083] Furthermore, when the fan 20 rotates, the pressure at the air outlet 28 of the fan 20 becomes higher than the pressure on the inlet 2 side of the fan 20. Therefore, as shown by arrows F4 and F5, air flows in the gap passage 84, flowing backward from the air outlet 28 side to the inlet 2 side. Note that the air flowing backward through the gap passage 84 contains a velocity component in the rotation direction of the fan 20. The air flowing through the gap passage 84, as shown by arrows F4 and F5, and the air flowing in from the first passage 81, as shown by arrow F2, join together in the second passage 82, and are then sucked into the inter-blade passage 25 from the blade leading edge 26 side together with the main flow, as shown by arrow F3.

[0084] Here, the pressure of the air flowing along the radially outer surface of the nozzle 60 is higher than the pressure of the mainstream air flowing into the fan 20 along the radially inner surface of the nozzle 60. Therefore, the pressure difference between the pressure in the first flow path 81, the partition flow path 73, and the second flow path 82 and the pressure on the air outlet 28 side of the fan 20 becomes smaller, and the amount of air flowing back through the gap flow path 84 from the air outlet 28 side of the fan 20 can be reduced.

[0085] Furthermore, when the air flowing through the first flow passage 81 and the air that has flowed backward through the gap flow passage 84 join together in the second flow passage 82, the velocity component of the joined air in the rotational direction of the fan 20 decreases. Therefore, the angle of intersection between the air blown out from the second flow passage 82 toward the blade leading edge 26 and the main flow decreases, making it possible to reduce noise.

[0086] <Foot mode or defroster mode> Next, the air flow when the air conditioner is in foot mode or defroster mode and the blower 1 is operated will be described with reference to FIG.

[0087] As the fan 20 rotates, the main flow is drawn into the inter-blade passage 25 from the leading edge 26 of the fan 20 along the radially inner surface of the nozzle 60, as indicated by arrow F1 in FIG. 15 . Generally, when an air conditioner is in foot mode or defroster mode, the pressure loss in the passage downstream of the blower 1 is greater than in face mode. Therefore, as the rotation speed of the fan 20 increases, the difference in pressure between the air outlet 28 side and the air inlet 2 side of the fan 20 becomes greater than the pressure difference in face mode. As a result, when the velocity and volume of air flowing back through the gap passage 84 increase, the backflow air attempts to flow from the second passage 82 through the partition passage 73 and the first passage 81, straddle the end 61 of the nozzle 60 on the anti-main-plate side, and into the inside of the nozzle 60, as indicated by dashed arrow F6 in FIG. 15 . In contrast, in the sixth embodiment, the space between the nozzle 60 and the bell mouth 11 is partitioned into multiple partitioned flow paths 73 by multiple flow path partition members 70, so that the pressure loss of the backflow air passing through the partitioned flow paths 73 increases, and the wind speed and volume of the backflow air are reduced.

[0088] Furthermore, research by the inventors has revealed that the backflow air that attempts to flow inside the nozzle 60 across the end 61 of the nozzle 60 on the side opposite to the main plate has a large circumferential wind speed distribution. In contrast, in the first embodiment, the space between the nozzle 60 and the bellmouth 11 is partitioned into a plurality of partition flow paths 73 by a plurality of flow path partition members 70, so that the pressure loss of the backflow air passing through the partition flow paths 73 increases and the circumferential wind speed distribution of the backflow air is reduced.

[0089] Like the blower 1 described in the first embodiment and the like, the blower 1 of the sixth embodiment described above can reduce the speed and volume of backflow air passing through the plurality of partition flow paths 73 and reduce the circumferential speed distribution of the backflow air across the nozzle 60. Therefore, the blower 1 of the sixth embodiment can also improve the blowing efficiency and reduce noise.

[0090] (Other embodiments) (1) In each of the above embodiments, the blower 1 has been described as being used in a vehicle air conditioning system, but this is not limited thereto, and the blower 1 can be used for various purposes, such as a ventilation system or an air blowing system.

[0091] (2) In the above embodiments, the fan 20 included in the blower 1 is described as a turbofan. However, the present invention is not limited to this and may be, for example, a centrifugal fan such as a sirocco fan or a radial fan.

[0092] (3) In the above embodiments, the nozzle 60 of the blower 1 has been described as having a blade shape whose diameter decreases from one side to the other in the axial direction and as being provided so as to protrude beyond the front wall 12 of the case 10 on the side opposite the main board, but this is not limited thereto. The nozzle 60 may have, for example, a simple cylindrical shape, and may not protrude beyond the front wall 12 of the case 10 on the side opposite the main board.

[0093] (4) In each of the above embodiments, the numbers of flow path partition members 70 are exemplified as 14, 20, 21, and 24 in each figure, but this is not limited thereto, and the number and shape of the flow path partition members 70 can be set arbitrarily.

[0094] The present invention is not limited to the above-described embodiments and can be modified as appropriate within the scope of the claims. Furthermore, the above-described embodiments are not unrelated to each other and can be combined as appropriate unless the combination is clearly impossible. It goes without saying that the elements constituting the embodiments are not necessarily essential unless specifically stated as essential or clearly considered essential in principle. Furthermore, when the numbers, values, amounts, ranges, etc. of the components of the embodiments are mentioned in the above-described embodiments, they are not limited to the specific numbers unless specifically stated as essential or clearly limited to a specific number in principle. Furthermore, when the shapes, positional relationships, etc. of the components are mentioned in the above-described embodiments, they are not limited to the shapes, positional relationships, etc., unless specifically stated or clearly limited to a specific shape, positional relationship, etc. in principle. [Explanation of symbols]

[0095] 1 blower 2 Intake port 11 Bellmouth 20 fans 21 Main plate 22 Wings 30 Shroud 60 nozzles 70 Flow path partition member 73 Partition channel

Claims

1. In the blower, A case (10) having a bell mouth (11) that forms an intake port (2) for drawing in air; a fan (20) including a main plate (21) rotatably provided around a central axis (CL) inside the case, a plurality of blades (22) arranged around the central axis and connected to the main plate, and a shroud (30) connected to portions (23) of the plurality of blades on the opposite side to the main plate; a cylindrical nozzle (60) provided in a radially inner region of the bell mouth; and flow path partition members (70) that are provided intermittently in the circumferential direction between the nozzle and the bell mouth and that partition the space between the nozzle and the bell mouth into a plurality of partition flow paths (73) through which air flows, The flow path partition members are configured to have an increased number and a greater thickness so that the pressure loss of air passing through the partition flow path increases compared to the number and thickness required to support the nozzles when viewed from the axial direction.

2. The blower according to claim 1 , wherein the flow path partition members are provided radially between the nozzle and the bell mouth.

3. The blower according to claim 1 or 2, wherein the flow path partition members are provided at uniform intervals in the circumferential direction between the nozzle and the bell mouth.

4. A blower comprising: A case (10) having a bell mouth (11) that forms an intake port (2) for drawing in air; a fan (20) including a main plate (21) rotatably provided around a central axis (CL) inside the case, a plurality of blades (22) arranged around the central axis and connected to the main plate, and a shroud (30) connected to portions (23) of the plurality of blades on the opposite side to the main plate; a cylindrical nozzle (60) provided in a radially inner region of the bell mouth; and flow path partition members (70) that are provided intermittently in the circumferential direction between the nozzle and the bell mouth and that partition the space between the nozzle and the bell mouth into a plurality of partition flow paths (73) through which air flows, The flow path partition member is provided in a net-like manner between the nozzle and the bell mouth so as to increase pressure loss of air flowing between the nozzle and the bell mouth.

5. 5. The blower according to claim 1, wherein the flow path partition member is provided over the entire periphery between the nozzle and the bell mouth.

6. an end (71) of the flow path partition member on the side opposite to the main plate is located closer to the main plate than an end (61) of the nozzle on the side opposite to the main plate, 6. The blower according to claim 1, wherein an end (72) of the flow path partition member on the side of the main board is located on the side opposite the main board from an end (62) of the nozzle on the side of the main board.

7. In the blower, A case (10) having a bell mouth (11) that forms an intake port (2) for drawing in air; a fan (20) including a main plate (21) rotatably provided around a central axis (CL) inside the case, a plurality of blades (22) arranged around the central axis and connected to the main plate, and a shroud (30) connected to portions (23) of the plurality of blades on the opposite side to the main plate; a cylindrical nozzle (60) provided in a radially inner region of the bell mouth; a plurality of flow path partition members (70) provided between the nozzle and the bell mouth and partitioning the space between the nozzle and the bell mouth into a plurality of partition flow paths (73) through which air flows; a blower having a plurality of flow path partition members at locations where the spacing between them is narrow and a plurality of the flow path partition members at locations where the spacing between them is wide, so that the wind speed of air flowing back through the space formed between the nozzle and the bell mouth from the air outlet side of the fan through the plurality of partition flow paths to the air inlet side inside the nozzle is made uniform.

8. The blower according to claim 7 , wherein the plurality of flow path partition members are provided only within a predetermined angular range set at a plurality of locations in the circumferential direction between the nozzle and the bell mouth.

9. The blower according to claim 7 , wherein the plurality of flow path partition members are provided at uneven intervals in the circumferential direction between the nozzle and the bell mouth.

10. 10. The blower according to claim 1, wherein the fan is a turbofan in which the blades extend rearward in the direction of rotation from a leading edge to a trailing edge.

11. 8. The blower according to claim 4, wherein the number of the flow path partition members is at least twice the number required to support the nozzles.

12. 12. The blower according to claim 1, wherein the shroud has a shroud annular portion (31) connected to portions (23) of the plurality of blades on the side opposite the main board, and does not have a portion of the shroud annular portion extending in a cylindrical shape from a radially inner portion toward the side opposite the main board.

13. 12. The blower according to claim 1, wherein the shroud has a shroud annular portion (31) connected to a portion (23) of the plurality of blades on the side opposite the main board, and a shroud cylindrical portion (32) extending in a cylindrical shape from a radially inner portion of the shroud annular portion toward the side opposite the main board.

Images