centrifugal blower

Abstract

To reduce a positional deviation amount between a motor support position at which a motor is supported and a gravity center position of a fan in a direction along a rotational axis, in a centrifugal blower.SOLUTION: A fan 4 of a centrifugal blower 1 has: a boss part 41 attached to an output shaft 31 of a motor 3 on one side of the output shaft 31 with respect to a motor support position 32a; a main plate 42 extending radially outward from the boss part 41 around the output shaft 31; a plurality of blades 43 extending from the main plate 42 to the one side of the output shaft 31; and a side plate 44 connected to the end parts of the blades 43 on one side of the output shaft. The main plate 42 is heavier than the side plate 44, and the main plate 42 and the side plate 44 are inclined radially outward toward the other side of the output shaft 31.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Patent Document 1 describes one of the objectives of a turbofan as being to reduce the distance from an axis-perpendicular plane that passes through the joint between the fan boss and main plate and is perpendicular to the rotation axis to the center of gravity of the blade.To achieve this objective, it describes forming the main plate so that its thickness gradually increases from the rotation axis side toward the outer periphery. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-281256 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the inventor's investigations, in the turbofan described in Patent Document 1, it is desirable to further reduce the misalignment between the motor support position, where the motor is supported on the case, and the center of gravity of the fan in the direction along the rotation axis. If this misalignment is long, the moment around the motor support position caused by the centrifugal force resulting from the combined imbalance between the fan and the motor rotor increases, which may result in insufficient suppression of vibrations in the turbofan. This is true not only for turbofans but also for centrifugal blowers in general.

[0005] SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to reduce the amount of misalignment between the motor support position and the center of gravity of the fan in the direction along the rotation axis in a centrifugal blower. [Means for solving the problem]

[0006] The invention described in claim 1 to achieve the above object is: A centrifugal blower, Case (2) and a motor (3) supported on the case at a motor support position (32a); a fan (4) that is driven to rotate by the motor, The fan is a boss portion (41) attached to the output shaft (31) of the motor on one side of the output shaft (31) of the motor relative to the motor support position; a main plate (42) extending radially outward from the boss portion about the output shaft; a plurality of blades (43) extending from the main plate to one side of the output shaft; a side plate (44) connected to one end of the output shaft of the plurality of blades, The main plate is heavier than the side plates, The main plate and the side plate are inclined radially outward toward the other side of the output shaft. And, The centrifugal blower has a main plate having an average thickness greater than that of the side plates. The invention described in claim 7 is as follows: A centrifugal blower, Case (2) and a motor (3) supported on the case at a motor support position (32a); a fan (4) that is driven to rotate by the motor, The fan is a boss portion (41) attached to the output shaft (31) of the motor on one side of the output shaft (31) of the motor relative to the motor support position; a main plate (42) extending radially outward from the boss portion about the output shaft; a plurality of blades (43) extending from the main plate to one side of the output shaft; a side plate (44) connected to one end of the output shaft of the plurality of blades, The main plate is heavier than the side plates, the main plate and the side plate are inclined radially outward toward the other side of the output shaft, the main plate has a first sloped portion (42a) in which the gradient of the slope toward the other side of the output shaft when moving radially outward is within a first range, and a second sloped portion (42b) in which the gradient is within a second range different from the first range and which is located radially outward of the first sloped portion, the main plate has an outer peripheral end portion (42c) that is located radially outward of the second gradient portion and at the outermost periphery of the main plate, The centrifugal blower is such that the thickness of the outer peripheral end portion is smaller than the thickness of the second gradient portion.

[0007] In this way, the main plate, which is located on the other side of the output shaft relative to the side plates, is heavier than the side plates, thereby reducing the amount of misalignment along the output shaft between the motor support position and the center of gravity of the fan. Also, because the main plate and the side plates are inclined radially outward from the output shaft toward the other side of the output shaft, the blades can be positioned closer to the other side of the output shaft, allowing the center of gravity of the fan to be positioned closer to the other side in the direction along the output shaft. In other words, the amount of misalignment along the output shaft between the motor support position and the center of gravity of the fan can be reduced.

[0008] 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]

[0009] [Figure 1] 1 is a cross-sectional view including a rotary shaft of a centrifugal blower according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II of FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along the line III-III in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. [Figure 5] FIG. 10 is a cross-sectional view including a rotation shaft of a centrifugal blower 1 according to a second embodiment. [Figure 6] FIG. 4 is a plan view of the fan as seen from the other axial side. [Figure 7] FIG. 11 is a plan view of the fan according to the third embodiment, as seen from the other axial side. [Figure 8] FIG. 11 is a plan view of the fan according to the fourth embodiment, as seen from the other axial side. [Figure 9] FIG. 10 is a cross-sectional view including a rotary shaft of a centrifugal blower according to a fifth embodiment. [Figure 10] FIG. 10 is a cross-sectional view including a rotary shaft of a centrifugal blower according to a sixth embodiment. [Figure 11] FIG. 11 is a cross-sectional view including a rotary shaft of a centrifugal blower according to a seventh embodiment. [Figure 12] 12 is a cross-sectional view taken along the line XII-XII of FIG. 11. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described. In the following embodiments, parts that are the same as or equivalent to those described in the preceding embodiments will be given the same reference numerals, and their description may be omitted. Furthermore, in the embodiments, when only some of the components are described, the components described in the preceding embodiments can be applied to the remaining components. The following embodiments can be partially combined with each other, as long as there is no particular problem with the combination, even if not specifically stated.

[0011] (First embodiment) As shown in Fig. 1, the centrifugal blower 1 according to the first embodiment includes a case 2, a motor 3 supported by the case 2, and a fan 4 that is driven to rotate by the motor 3. Fig. 1 is a cross-sectional view of the centrifugal blower 1 along a plane including a rotation axis CL. The centrifugal blower 1 of this embodiment is a turbofan, but as another example, it may be a centrifugal blower other than a turbofan (for example, a sirocco fan).

[0012] The case 2 is a member that houses the motor 3 and the fan 4, and is made of, for example, resin, but may be made of other materials. The case 2 may be attached to another member (for example, a housing that forms the outer shell of the air conditioner).

[0013] The case 2 has a first case portion 21 and a second case portion 22. The first case portion 21 and the second case portion may be formed separately and then assembled to each other, or may be formed integrally as a whole. The first case portion 21 covers the suction side of the fan 4, and the second case portion 22 covers the side opposite to the suction side of the fan 4 and has the motor 3 attached thereto.

[0014] The motor 3 has an output shaft 31, a rotor holder 32, a bearing 33, a core 34, and a rotor 35. The motor 3 is an outer rotor type electric motor, but may alternatively be an inner rotor type.

[0015] The output shaft 31 is a rod that transmits the rotational force generated by the motor 3 to the fan 4. The output shaft 31 and the rotation axis CL are substantially coaxial. The rotating body holding part 32 is, for example, a member made of metal or resin, and is fixedly attached to the second case part 22 at the motor support position 32a. The fixed attachment of the rotating body holding part 32 to the second case part 22 may be achieved, for example, by fastening with bolts or screws, or by other methods.

[0016] The motor support position 32a is located outside the outermost edge of the rotor 35 in the radial direction centered on the output shaft 31. Furthermore, the motor support position 32a is located outside the connection position of a boss portion 41 (described later) and the output shaft 31 in the radial direction centered on the output shaft 31. Furthermore, the motor support position 32a is located lower in FIG. 1 than the connection position of the boss portion 41 and the output shaft 31 and the connection position of the rotor 35 and the output shaft 31 in the direction along the output shaft 31.

[0017] Hereinafter, the direction along the output shaft 31 will be simply referred to as the axial direction FL, the upper side of the axial direction FL in Fig. 1 will be referred to as one side, and the lower side of the axial direction FL in Fig. 1 will be referred to as the other side. In addition, the radial direction and circumferential direction about the output shaft 31 will be simply referred to as the radial direction and circumferential direction, respectively.

[0018] The bearing 33 is attached to the surface of the rotor holder 32 on the output shaft 31 side, and rotatably supports the output shaft 31. In this way, the rotor holder 32 holds the output shaft 31, the rotor 35, and the fan 4 via the bearing 33.

[0019] When current is applied to the core 34, it generates a magnetic field, thereby rotating the rotor 35. The core 34 is fixed to the rotor holder 32. The rotor holder 32 and the core 34 form a stator.

[0020] The rotor 35 is fixed to the output shaft 31 at its radially inner circumferential edge, and is disposed on the outer peripheral side of the core 34 at its radially outer circumferential edge. The rotor 35 is provided with a magnet on the radially outer circumferential side of the core 34, and receives a rotational force from a magnetic field generated by the core 34 by the magnet. In this motor 3, when the core 34 is energized, a magnetic field is generated, and the rotor 35 rotates integrally with the output shaft 31 due to the magnetic field. At this time, the output shaft 31 is journaled by a bearing 33.

[0021] The fan 4 has a boss portion 41, a main plate 42, a plurality of blades 43, and a side plate 44. In this embodiment, the boss portion 41, the main plate 42, the plurality of blades 43, and the side plate 44 are all integrally molded from the same material (e.g., resin). The mass density of the fan 4 is uniform. The boss portion 41 is an annular member attached to the output shaft 31. The connection position between the boss portion 41 and the output shaft 31 is located on one side of the connection position between the rotor 35 and the output shaft 31 and the motor support position 32a in the axial direction FL.

[0022] The main plate 42 is a plate-shaped member that is connected to the boss portion 41 at its radially inner peripheral edge and extends from the boss portion 41 radially outward around the output shaft 31. The plurality of blades 43 are plate-shaped members. Each blade 43 extends from one surface of the main plate 42 in the axial direction FL toward one side in the axial direction FL, and is connected to the side plate 44 at its end on one side in the axial direction FL. The plurality of blades 43 are arranged side by side in the circumferential direction around the output shaft 31. Furthermore, each blade 43 extends so that the farther it is from the output shaft 31, the more rearward it is in the direction of rotation of the fan 4. The rotation direction coincides with the circumferential direction.

[0023] The side plate 44 is a plate-shaped member that is disposed so as to surround the output shaft 31 and extends radially outward. As described above, the plurality of blades 43 are connected to the surface of the side plate 44 on the other side in the axial direction FL. The first case portion 21 is disposed so as to face the surface of the side plate 44 on one side in the axial direction FL and cover the side plate 44 from one side in the axial direction FL.

[0024] The side plate 44 has a main body portion 44a and a tubular portion 44b. The main body portion 44a is disposed opposite the main plate 42 and sandwiches the plurality of blades 43 between itself and the main plate 42. The tubular portion 44b is an annular portion that extends from the radially inner circumferential end of the main body portion 44a, bending relative to the main body portion 44a and extending to one side in the axial direction FL. The tubular portion 44b faces the output shaft 31 and surrounds the output shaft 31, thereby forming an air inlet IP on its radially inner circumferential side for taking in air.

[0025] The boss portion 41, main plate 42, blades 43, and side plate 44 configured as described above rotate together as a whole when a rotational force is transmitted from the output shaft 31. As a result, the output shaft 31, rotor 35, and fan 4 rotate together toward the front in the rotational direction.

[0026] The operation of the centrifugal blower 1 configured as described above will now be described. When the core 34 of the motor 3 is energized, the core 34 generates a magnetic force, which rotates and drives the rotor 35. As a result, the rotor 35, output shaft 31, and fan 4 rotate together. As a result, air is sucked from one side to the other in the axial direction FL at the air inlet IP, flows between the main plate 42 and the side plate 44 and between the multiple blades 43 from the radially inner side to the radially outer side, and is then blown out from the radially outermost periphery of the fan 4.

[0027] In this centrifugal blower 1, a complex imbalance exists between the fan 4 and the rotor 35. This imbalance occurs when the mass of the rotating body around the rotation axis is not uniformly distributed in the circumferential direction (e.g., eccentricity). Here, the rotating body is the fan 4 and the rotor 35. A moment around the motor support position 32a, which is generated due to centrifugal force F caused by this imbalance, causes vibration of the centrifugal blower 1. If this moment increases, the suppression of vibration of the centrifugal blower 1 may become insufficient. This moment increases as the positional deviation L between the motor support position 32a and the center of gravity G of the fan 4 along the axial direction FL increases. The centrifugal blower 1 of this embodiment is configured to suppress this positional deviation L.

[0028] The features of the centrifugal blower 1 will be described in more detail below. First, the main plate 42 and the side plate 44 are inclined radially outward toward the other side in the axial direction FL. That is, each of the main plate 42 and the side plate 44 extends radially outward so as to be positioned closer to the other side in the axial direction FL.

[0029] This allows the blades 43 to be positioned further to the other side in the axial direction FL, and therefore the center of gravity G of the fan 4 to be positioned further to the other side in the axial direction FL. This reduces the amount of misalignment L, and ultimately reduces vibration of the centrifugal fan 1 caused by imbalance.

[0030] Furthermore, the main plate 42 is heavier than the side plate 44. This allows the center of gravity G of the fan 4 to be positioned closer to the main plate 42, and therefore the center of gravity G can be positioned closer to the other side in the axial direction FL, thereby reducing the amount of positional deviation L.

[0031] (1) Specifically, the main plate 42 has a greater thickness than the side plate 44. This comparison is obvious if the thickness of each of the main plate 42 and the side plate 44 is uniform, but if not, the comparison is made based on the average plate thickness. The average plate thickness is calculated by dividing the volume of the plate by the area of ​​the plate surface.

[0032] This allows the main plate 42 and the side plate 44 to have different thicknesses, which can be used to reduce the amount of positional deviation along the output shaft between the motor support position and the center of gravity of the fan.

[0033] (2) Furthermore, the length from one end of the fan 4 to the other end along the axial direction FL is defined as h1. This length h1 is also referred to as the overall height of the fan 4. The length along the output shaft from the connection position between the boss portion 41 and the output shaft 31 to the end of the fan 4 on the other side in the axial direction FL is defined as h2. This length h2 is also referred to as the height of the boss portion 41. In this case, the length h2 is at least half the length h1.

[0034] This allows the inclination of the main plate 42 connected to the boss portion 41 to be made steeper, and allows the blades 43 to be attached further to the other side in the axial direction FL relative to the overall height of the fan 4. Consequently, the positional deviation L can be reduced.

[0035] (3) Furthermore, the main plate 42 has a first gradient portion 42a and a second gradient portion 42b. The first gradient portion 42a is disposed radially inward of the second gradient portion 42b on the main plate 42. Furthermore, the radially inner end of the first gradient portion is connected to the boss portion 41.

[0036] In the first gradient section 42a, the gradient of the inclination toward the other side in the axial direction FL when moving radially outward falls within a first range. This gradient increases as the amount of change toward the other side in the axial direction FL increases per unit distance from the output shaft 31. In other words, it is the depression angle. The gradient is determined based on the midpoint between the one end and the other end in the axial direction FL at each position.

[0037] In addition, in the second gradient portion 42b, the gradient of the inclination toward the other side in the axial direction FL when moving radially outward falls within a second range that is different from the first range. Note that the first range and the second range may partially overlap, or may not overlap at all. This allows for more flexible measures to reduce the amount of misalignment L than when the gradient of the main plate 42 is constant.

[0038] (4) The first range has a steeper slope than the second range. That is, the upper limit of the first range is greater than the upper limit of the second range, and the lower limit of the first range is greater than the lower limit of the second range. The average of the upper and lower limits of the first range is greater than the average of the upper and lower limits of the second range.

[0039] This configuration allows the second gradient portion 42b, which may have a larger volume because it is located radially outward of the first gradient portion 42a, to be located more eccentrically on the other side in the axial direction FL, thereby reducing the amount of positional deviation L.

[0040] (5) The average thickness of the second gradient portion 42b is greater than the average thickness of the first gradient portion 42a. In this way, by increasing the average thickness of the second gradient portion 42b located on the other side of the main plate 42 in the axial direction FL, the positional deviation L can be effectively reduced.

[0041] In this embodiment, the average thickness of the second gradient portion 42b is greater than the average thickness of the side plate 44, but in other examples, it may not be greater. Also, the average thickness of the first gradient portion 42a may be greater or smaller than the average thickness of the side plate 44.

[0042] (6) Furthermore, the main plate 42 has an outer peripheral end portion 42c that is radially outward of the second gradient portion 42b and is located at the outermost periphery of the main plate 42. The average thickness of this outer peripheral end portion 42c is smaller than the average thickness of the second gradient portion 42b. In this way, by thinning the outer peripheral end portion 42c of the main plate 42 that slopes radially outward toward the other side in the axial direction FL, the height of the fan 4, i.e., the length from one end to the other end of the fan 4 along the axial direction FL, can be reduced.

[0043] More specifically, at the outer peripheral end 42c, the gradient of the inclination of the surface facing one side in the axial direction FL toward the radially outward direction is greater than the gradient of the inclination of the surface facing the other side in the axial direction FL toward the radially outward direction. As a result, the outer peripheral end 42c tapers toward the radially outward direction. For example, at the outer peripheral end 42c, the position of the surface facing one side in the axial direction FL may be such that the position of the surface facing the other side in the axial direction FL is positively gradient toward the other side in the axial direction FL as it moves radially outward, and the position of the surface facing the other side in the axial direction FL may not change as it moves radially outward.

[0044] In this way, at the outer peripheral end 42c, the plate thickness is gradually reduced as it moves radially outward, thereby preventing the surface on the other side in the axial direction FL from tilting too far to the other side in the axial direction FL. As another example, the position of the surface facing the other side in the axial direction FL may move toward one side in the axial direction FL or toward the other side in the axial direction FL as it moves radially outward.

[0045] (7) As shown in FIG. 2, the corners R1a and R1b formed at the joint between each of the plurality of blades 43 and the main plate 42 are rounded corners. As shown in FIG. 3, the corners R2a and R2b formed at the joint between each of the plurality of blades 43 and the side plate 44 are also rounded corners. The radius of curvature of the corners R1a and R1b of each blade 43 is larger than the radius of curvature of the corners R2a and R2b of the same blade. The corners R2a and R2b may be pin angles. In this case, the radius of curvature of the corners R1a and R1b of each blade 43 is also larger than the radius of curvature of the corners R2a and R2b of the same blade.

[0046] More specifically, what is compared here is the average value of the radius of curvature from the radial inner edge to the radial outer edge of the corners R1a and R1b at the joint with the main plate 42, and the average value of the radius of curvature from the radial inner edge to the radial outer edge of the corners R2a and R2b at the joint with the side plate 44.

[0047] As a result, in each blade 43, the joint with the main plate 42 is thicker than the joint with the side plate 44. By making the radius of curvature of the corners on the main plate side and the side plate side different in this way, it is possible to reduce the amount of misalignment along the output shaft 31 between the motor support position 32a and the center of gravity G of the fan 4.

[0048] The blades having the above-described relationship between the corners R1a, R1b, R2a, and R2b may be all or some of the blades 43. If the above-described relationship is established for at least one blade 43 among the blades 43, the above-described effect is realized for that blade 43.

[0049] (8) As shown in Figures 2 and 4, the radius of curvature of each of the corners R1a, R2a at the joint between the at least one blade 43 and the main plate 42 increases radially outward. This increase may be gradual or stepwise. Furthermore, the radius of curvature of each of the corners R1a, R2a may increase radially outward only in a portion of the joint between the blade 43 and the main plate 42 (for example, only in the joint between the blade 43 and the second sloped portion 42b).

[0050] In this way, by utilizing the fact that the radius of curvature of the corner can be changed depending on the radial position of the same blade 43, it is possible to reduce the amount of positional deviation along the output shaft 31 between the motor support position 32a and the center of gravity G of the fan 4. This is because the main plate 42 is inclined radially outward and toward the other side of the output shaft 31.

[0051] (9) Also, as shown in FIG. 1, the leading edge portion 43a, which is the end portion on the output shaft 31 side of each of the multiple blades 43, is connected to the surface of the tubular portion 44b on the output shaft 31 side at one end in the axial direction FL.

[0052] This configuration improves the rigidity of each blade 43, thereby suppressing deformation of the fan 4. Note that, as described above, all of the blades 43 may have this structure, or only some of the blades 43. Even in the latter case, the rigidity of those some of the blades 43 is improved.

[0053] In this embodiment, each of the blades 43 has a constant thickness except for the joints with the main plate 42 and the joints with the side plate 44. Furthermore, no protrusions such as ribs are formed on the surface of the main plate 42 on the other side in the axial direction FL in this embodiment.

[0054] (Second embodiment) Next, a second embodiment will be described with reference to Figs. 5 and 6. The centrifugal blower 1 according to this embodiment differs from the first embodiment in the configuration of the main plate 42. Specifically, as shown in Figs. 5 and 6, the main plate 42 has a plurality of ribs 42d. Furthermore, the outer peripheral end 42c of this embodiment has the same thickness as the second sloped portion 42b, but as in the first embodiment, the outer peripheral end 42c may have a smaller thickness than the second sloped portion 42b. The other configurations are the same as those of the first embodiment.

[0055] The plurality of ribs 42d protrude from the surface of the main plate 42 opposite the side plate 44 toward the other side in the axial direction FL. Each of the ribs 42d is arranged in an annular shape around the output shaft 31, surrounding the output shaft 31. The ribs 42d are arranged in multiple layers from the inside to the outside in the radial direction as a whole. The number of ribs 42d may be multiple as described above, or may be one. The rib 42d may be attached only to the second sloped portion 42b as shown in FIGS. 5 and 6, or may be attached to both the first sloped portion 41a and the second sloped portion 42b, or may be attached only to the first sloped portion 41a.

[0056] Furthermore, in the present embodiment, the portion of the main plate 42 that is located furthest to the other side in the axial direction FL is not one of the plurality of ribs 42d but the end portion of the outer peripheral end portion 42c on the other side in the axial direction FL. This reduces the possibility that the plurality of ribs 42d will increase the dimension of the fan 4 in the axial direction FL.

[0057] (1) As described above, the main plate 42 has one or more ribs 42d that protrude from the surface opposite the side plate 44 toward the other side of the output shaft 31. This reduces the amount of misalignment L by the weight of the ribs 42d.

[0058] (2) Furthermore, the rib 42d is arranged in a ring shape surrounding the output shaft 31. This makes it less likely that the rib 42d will cause resistance to the rotation of the fan 4. The rib 42h may be centered on the output shaft 31 as described above, or may be centered at a position offset from the output shaft 31. The rib 42h may be formed only on the second gradient portion 42b as shown in FIG. 6, or may be formed on both the first gradient portion 42a and the second gradient portion 42b. Furthermore, the same effects can be obtained in this embodiment from a configuration similar to that of the first embodiment.

[0059] (Third embodiment) Next, a third embodiment will be described with reference to Fig. 7. The centrifugal blower 1 according to this embodiment differs from the second embodiment in that the multiple ribs 42d are replaced with multiple ribs 42e. The rest of the configuration is the same as that of the second embodiment. Each of the multiple ribs 42e extends radially from the inner side to the outer side in the radial direction around the output shaft 31.

[0060] In this embodiment, the portion of the main plate 42 that is located closest to the other side in the axial direction FL is not one of the plurality of ribs 42e, but the end portion of the outer circumferential end portion 42c on the other side in the axial direction FL.

[0061] The number of ribs 42e may be multiple as described above, or may be 1. Furthermore, the rib 42e may be attached only to the second gradient portion 42b as shown in Fig. 7, or to both the first gradient portion 41a and the second gradient portion 42b, or only to the first gradient portion 41a.

[0062] Furthermore, in this embodiment, one or more ribs 42d having the shape shown in the third embodiment may be further provided. That is, the rib 42d and the rib 42e may be formed in combination on the main plate 42. Furthermore, in this embodiment, the same effects as those in the first and second embodiments can be obtained from the same configuration.

[0063] (Fourth embodiment) Next, a fourth embodiment will be described with reference to Fig. 8. In the centrifugal fan 1 according to this embodiment, the plurality of ribs 42e of the third embodiment are replaced with a plurality of ribs 42f. The rest of the configuration is the same as that of the third embodiment.

[0064] The multiple ribs 42f are arranged side by side in the circumferential direction centered on the output shaft 31. Each of the multiple ribs 42f extends in a wing shape that faces more rearward in the rotation direction as it moves away from the output shaft 31. That is, the orientation of the multiple ribs 42f is the same as that of the multiple wings 43.

[0065] As another example, the orientation of the multiple ribs 42f may be opposite to that of the multiple blades 43. That is, each of the multiple ribs 42f may extend in a blade shape that faces more forward in the rotation direction as it moves away from the output shaft 31. Furthermore, the number of the multiple ribs 42f may be the same as or different from the number of the multiple blades 43. The number of rib 42f may be one.

[0066] In this embodiment, the portion of the main plate 42 that is located closest to the other side in the axial direction FL is not one of the plurality of ribs 42f, but the end portion of the outer circumferential end portion 42c on the other side in the axial direction FL.

[0067] The number of ribs 42f may be multiple as described above, or may be one. Furthermore, the rib 42f may be attached only to the second gradient portion 42b as shown in Fig. 8, or to both the first gradient portion 41a and the second gradient portion 42b, or to only the first gradient portion 41a. Furthermore, in this embodiment, the same effects can be obtained from the same configuration as in the first to third embodiments.

[0068] (Fifth embodiment) Next, a fifth embodiment will be described with reference to Fig. 9. The centrifugal blower 1 according to this embodiment differs from the first embodiment in the materials that make up the boss portion 41 and the main plate 42. The other configurations are the same as those of the first embodiment. Note that the changes made in this embodiment can also be applied to the second to fourth embodiments.

[0069] In this embodiment, the boss portion 41 and the main plate 42 are formed from a material with a higher mass density than the blades 43 and the side plates 44. The material forming the boss portion 41 and the main plate 42 may be resin or metal. This makes the main plate 42 heavier than in the third embodiment, and as a result, the center of gravity G of the fan 4 is located further to the other side in the axial direction FL.

[0070] In this embodiment, the boss portion 41 and the main plate 42 may be formed separately from the blades 43 and the side plates 44, and then the blades 43 and the main plate 42 may be connected by welding or the like to manufacture the fan 4. Alternatively, the boss portion 41 and the main plate 42 may be formed together with the blades 43 and the side plates 44 by two-color molding.

[0071] As in the first embodiment, the boss portion 41 may be made of the same material as the blades 43 and the side plates 44. Alternatively, the blades 43 may be made of the same material as the main plate 42. In either case, the same effect can be obtained.

[0072] (1) As described above, the main plate 42 is formed of a material having a higher mass density than the side plate 44. This configuration makes it possible to reduce the amount of misalignment L by using different materials for the main plate 42 and the side plate 44. Furthermore, in this embodiment, the same effects can be obtained from the same configurations as in the first to fourth embodiments.

[0073] (Sixth embodiment) Next, a sixth embodiment will be described with reference to Fig. 10. The centrifugal blower 1 according to this embodiment differs from the first embodiment in the material that constitutes the fan 4. The rest is the same as the first embodiment. Note that the changes made in this embodiment can also be applied to the second to fifth embodiments.

[0074] In this embodiment, all components of the fan 4, such as the boss portion 41, blades 43, and side plates 44, are made of resin, except for the main plate 42. As shown in FIG. 10, the first gradient portion 42a and the outer peripheral edge 42c of the main plate 42 are made of resin. The second gradient portion 42b has a metal portion made of metal and a resin portion made of resin and surrounding the metal portion. This metal has a higher mass density than the resin. As a result, the mass density of the main plate 42 is higher than the mass density of the side plates 42.

[0075] The fan 4 having this configuration can be manufactured by, for example, resin molding with a metal insert, i.e., insert molding. Note that, like the second sloped portion 42b, the first sloped portion 42a and the outer peripheral end portion 42c may also be partially made of metal.

[0076] (1) As described above, the second sloped portion 42b has a metal portion and a resin portion surrounding the metal portion. This configuration makes the main plate heavier, thereby reducing the amount of misalignment L. In addition, the same effects as those of the first to fifth embodiments can be obtained in this embodiment from the same configuration.

[0077] Seventh embodiment Next, a seventh embodiment will be described with reference to Figs. 11 and 12. The centrifugal fan 1 according to this embodiment has a modified shape of the blades 43 compared to the first embodiment. The rest of the configuration is the same as that of the first embodiment. Note that the modifications of this embodiment can also be applied to the second to sixth embodiments.

[0078] In each of the multiple wings 43 of this embodiment, the thickness of a portion closer to the main plate 42 than to the side plate 44 is greater than the thickness of a portion closer to the side plate 44 than to the main plate 42. Specifically, as shown in Fig. 12, the thickness of the main body portion of each wing 43, excluding the joint portion with the main plate 42 and the joint portion with the side plate 44, gradually decreases as it moves away from the main plate 42 and approaches the side plate 44. In addition to the gradual decrease in thickness of the main body portion from the main plate 42 to the side plate 44 in this way, the thickness may also decrease in stages.

[0079] (1) As described above, in each blade 43, the thickness of the portion closer to the main plate 42 is greater than the thickness of the portion closer to the side plate 44. This configuration makes it possible to reduce the misalignment amount L by making the thickness of the same blade 43 different on the side closer to the main plate 42 than on the side closer to the side plate 44.

[0080] It should be noted that the blades 43 having the above-described characteristics may be some, not all, of the plurality of blades 43. In other words, as long as there is one or more blades 43 having the above-described characteristics, the above-described effects can be obtained to some extent.

[0081] (Other embodiments) The present invention is not limited to the above-described embodiments and can be modified as appropriate. The above-described embodiments are not unrelated to each other and can be combined as appropriate unless the combination is clearly impossible. In the above-described embodiments, the elements constituting the embodiments are not necessarily essential unless expressly stated as essential or clearly considered essential in principle. In the above-described embodiments, when numerical values ​​such as the number, value, amount, and range of components of the embodiments are mentioned, they are not limited to the specific number unless expressly stated as essential or clearly limited to a specific number in principle. In the above-described embodiments, when multiple values ​​are exemplified for a certain quantity, values ​​between those multiple values ​​can be adopted unless otherwise specified or clearly impossible in principle. In the above-described embodiments, when the shape, positional relationship, etc. of components are mentioned, they are not limited to the shape, positional relationship, etc., unless expressly stated or limited to a specific shape, positional relationship, etc. in principle. The present invention also allows the following modifications and modifications within equivalent ranges to the above-described embodiments. The following modifications can be independently applied or inapplicable to the above-described embodiments. That is, any combination of the following modifications can be applied to the above embodiment. [Explanation of symbols]

[0082] 4 Fans 41 Boss section 42 Main plate 43 Wings 44 Side panel 32a Motor support position

Claims

1. A centrifugal blower, Case (2) and a motor (3) supported on the case at a motor support position (32a); a fan (4) that is driven to rotate by the motor, The fan is a boss portion (41) attached to the output shaft (31) of the motor on one side of the output shaft (31) of the motor relative to the motor support position; a main plate (42) extending radially outward from the boss portion around the output shaft; a plurality of blades (43) extending from the main plate to one side of the output shaft; a side plate (44) connected to one end of the output shaft of the plurality of blades, The main plate is heavier than the side plates, the main plate and the side plate are inclined radially outward toward the other side of the output shaft, The centrifugal blower, wherein the main plate has an average thickness greater than that of the side plates.

2. 2. The centrifugal blower according to claim 1, wherein a length (h2) along the output shaft from a connection position between the boss portion and the output shaft to an end of the fan on the other side of the output shaft is at least half a length (h1) from the end of the fan on one side along the output shaft to the end on the other side.

3. 3. The centrifugal blower according to claim 1, wherein the main plate has a first sloped portion (42a) in which the gradient of the slope toward the other side of the output shaft when moving radially outward is within a first range, and a second sloped portion (42b) in which the gradient is within a second range different from the first range and which is located radially outward of the first sloped portion.

4. The centrifugal blower according to claim 3 , wherein the first range has a steeper slope than the second range.

5. 5. The centrifugal blower according to claim 3, wherein the second gradient portion has a thickness greater than that of the first gradient portion.

6. The main plate has an outer peripheral end portion (42c) that is located radially outward of the second gradient portion and is at the outermost periphery of the main plate, 6. The centrifugal blower according to claim 3, wherein the thickness of the outer peripheral end portion is smaller than the thickness of the second gradient portion.

7. A centrifugal blower, Case (2) and a motor (3) supported on the case at a motor support position (32a); a fan (4) that is driven to rotate by the motor, The fan is a boss portion (41) attached to the output shaft (31) of the motor on one side of the output shaft (31) of the motor relative to the motor support position; a main plate (42) extending radially outward from the boss portion around the output shaft; a plurality of blades (43) extending from the main plate to one side of the output shaft; a side plate (44) connected to one end of the output shaft of the plurality of blades, The main plate is heavier than the side plates, the main plate and the side plate are inclined radially outward toward the other side of the output shaft, the main plate has a first gradient portion (42a) in which the gradient of the inclination toward the other side of the output shaft when moving radially outward is within a first range, and a second gradient portion (42b) in which the gradient is within a second range different from the first range and which is located radially outward of the first gradient portion, The main plate has an outer peripheral end portion (42c) that is located radially outward of the second gradient portion and is at the outermost periphery of the main plate, A centrifugal blower, wherein the outer peripheral end portion has a thickness smaller than the thickness of the second gradient portion.

8. The side plate is a resin member, 8. The centrifugal blower according to claim 3, wherein the second gradient portion has a metal portion made of metal and a resin portion made of resin and surrounding the metal portion.

9. 9. The centrifugal blower according to claim 1, wherein a radius of curvature of a corner (R1a, R1b) at a joint between at least one of the plurality of blades and the main plate is larger than a radius of curvature of a corner (R2a, R2b) at a joint between the at least one blade and the side plate.

10. 10. The centrifugal blower according to claim 9, wherein the radius of curvature of the corner at the joint between the at least one blade and the main plate increases radially outward.

11. 11. The centrifugal blower according to claim 1, wherein in one or more of the plurality of blades, the thickness of a portion closer to the main plate than the side plate is greater than the thickness of a portion closer to the side plate than the main plate.

12. 12. The centrifugal blower according to claim 1, wherein the main plate has one or more ribs (42d, 42e, 42f) protruding from a surface opposite to the side plate toward the other side of the output shaft.

13. The centrifugal blower according to claim 12, wherein the one or more ribs are formed radially around the output shaft, annularly around the output shaft, or a combination thereof.

14. The centrifugal blower of claim 12 , wherein the one or more ribs are formed in an airfoil shape.

15. 15. The centrifugal fan according to claim 1, wherein the main plate is made of a material having a higher mass density than the side plates.

16. The side plate has a cylindrical portion (44b) that surrounds the output shaft and forms a suction port, 16. A centrifugal blower according to claim 1, wherein the ends of some or all of the plurality of blades on one side of the output shaft at leading edge portions (43a), which are the ends on the output shaft side, are connected to a surface of the cylindrical portion on the output shaft side on one side of the output shaft relative to the end of the cylindrical portion on the other side of the output shaft.

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