Centrifugal blower

Abstract

A centrifugal blower capable of suppressing vibration during rotation, increasing static pressure, and suppressing an increase in material cost is provided with a main plate that rotates about a rotation axis, a shroud, and a plurality of blades provided between the main plate and the shroud, the plurality of blades including first to third blades, the first blade having a first leading edge portion and a first trailing edge portion, and the second blade having a second leading edge portion and a second trailing edge portion. The first blade has a first leading edge portion and a first trailing edge portion, the second blade has a second leading edge portion and a second trailing edge portion, the third blade has a third leading edge portion and a third trailing edge portion, and when the length from the first leading edge portion to the first trailing edge portion is a first length, the length from the second leading edge portion to the second trailing edge portion is a second length, and the length from the third leading edge portion to the third trailing edge portion is a third length, the second length is larger than the first length. The first length is greater than the second length, the third length is greater than the second length, the number of the first to third blades is the same, the total number of the plurality of blades is a multiple of 3 of 6 or more, and the first to third blades are arranged in the order of the first blade, the second blade, and the third blade in the rotational direction.

Description

Technical Field

[0001] An embodiment of the present invention relates to a centrifugal blower. Background Art

[0002] It is known that a centrifugal blower is used in a heat exchanger or the like. In such a centrifugal blower, it is required to increase the static pressure equivalent to the differential pressure before and after the centrifugal blower passes. As a method of increasing the static pressure, it is considered to lengthen the length of the blade. However, if the blade is lengthened, the blade becomes heavier, so it is possible to generate vibration when rotating. In addition, if the blade is lengthened, the cost of the material may increase.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2017-125408 Summary of the invention

[0004] An object of the present invention is to provide a centrifugal blower capable of suppressing vibration during rotation and increasing static pressure, while suppressing an increase in material cost.

[0005] The centrifugal blower of the embodiment includes a main plate rotating around a rotating shaft, a shroud, and a plurality of blades arranged between the main plate and the shroud. The main plate includes a central portion and a peripheral portion. The peripheral portion is located outside the central portion. The plurality of blades include a first blade, a second blade, and a third blade. The first blade includes a first front edge portion, which is an end portion on the central portion side, and a first rear edge portion, which is an end portion on the peripheral portion side. The second blade includes a second front edge portion, which is an end portion on the central portion side, and a second rear edge portion, which is an end portion on the peripheral portion side. The third blade includes a third front edge portion, which is an end portion on the central portion side, and a third rear edge portion, which is an end portion on the peripheral portion side. When the length from the first front edge portion to the first rear edge portion is set as the first length, the length from the second front edge portion to the second rear edge portion is set as the second length, and the length from the third front edge portion to the third rear edge portion is set as the third length, the second length is greater than the first length. The third length is greater than the second length. The number of the first blades, the number of the second blades, and the number of the third blades are respectively the same. The total number of the plurality of blades is a multiple of 3 that is greater than 6, and the first blade, the second blade, and the third blade are arranged in the order of the first blade, the second blade, and the third blade in the rotation direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 It is a perspective view showing a centrifugal blower according to the embodiment.

[0007] Figure 2 It is a top view showing the centrifugal blower according to the embodiment.

[0008] Figure 3 It is a top view showing the centrifugal blower according to the embodiment.

[0009] Figure 4 It is a top view showing a part of the centrifugal blower according to the embodiment.

[0010] Figure 5 It is a perspective view showing a centrifugal blower according to the embodiment.

[0011] Figure 6 It is a top view showing the centrifugal blower according to the embodiment.

[0012] Explanation of symbols:

[0013] 10: main board; 10a: central part; 10b: outer periphery; 20: multiple blades; 20a: leading edge; 20b: trailing edge; 21: 1st blade; 21a: 1st leading edge; 21b: 1st trailing edge; 22: 2nd blade; 22a: 2nd leading edge; 22b: 2nd trailing edge; 23: 3rd blade; 23a: 3rd leading edge; 23b: 3rd trailing edge; 30: shroud; 100: centrifugal blower; AX: rotating axis; H1~H3: 1st to 3rd maximum heights; IL1~IL6: 1st to 6th imaginary lines; L1~L3: 1st to 3rd lengths; RD: rotating direction; T1~T3: 1st to 3rd maximum thicknesses; θ1~θ3: 1st to 3rd configuration angles; φ1~φ3: 1st to 3rd installation angles. DETAILED DESCRIPTION

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0015] The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the ratio of the size between parts, etc. are not necessarily the same as the actual ones. Even when the same part is shown, the size and ratio may be shown differently depending on the drawings.

[0016] In the present specification and each drawing, the same elements as those described with reference to the drawings already shown are denoted by the same reference numerals, and detailed description thereof will be appropriately omitted.

[0017] Figure 1 It is a perspective view showing a centrifugal blower according to the embodiment.

[0018] like Figure 1 As shown, a centrifugal blower 100 according to the embodiment includes a main plate 10 , a plurality of blades 20 , and a shroud 30 .

[0019] The main board 10 rotates along the rotation direction RD with the rotation axis AX as the center. The rotation axis extends along the Z direction. The main board 10 rotates along the XY plane orthogonal to the Z direction. The XY plane is a plane along the X direction orthogonal to the Z direction and the Y direction orthogonal to the Z direction and the X direction. In this example, the rotation direction RD is counterclockwise in the direction from the shield 30 toward the main board 10.

[0020] The main plate 10 has a central portion 10a and a peripheral portion 10b. The central portion 10a includes the intersection of the rotation axis AX and the main plate 10. The central portion 10a protrudes in the Z direction. The peripheral portion 10b is located outside the central portion 10a. The peripheral portion 10b extends along the XY plane.

[0021] The plurality of blades 20 are disposed between the main board 10 and the shield 30. The plurality of blades 20 are sandwiched between the main board 10 and the shield 30. The plurality of blades 20 are disposed, for example, along the Z direction. The plurality of blades 20 may also be disposed, for example, to be inclined relative to the Z direction.

[0022] The plurality of blades 20 extend from the central portion 10a of the main plate 10 toward the peripheral portion 10b. The plurality of blades 20 each have a leading edge 20a at the end portion on the central portion 10a side and a trailing edge 20b at the end portion on the peripheral portion 10b side. The plurality of blades 20 extend, for example, in a curved manner from the leading edge 20a toward the trailing edge 20b. The plurality of blades 20 may also extend, for example, in a straight line from the leading edge 20a toward the trailing edge 20b.

[0023] The shroud 30 covers the trailing edge portions 20b of the plurality of blades 20 in the Z direction. The trailing edge portions 20b of the plurality of blades 20 are located between the main board 10 and the shroud 30 in the Z direction. The shroud 30 is connected to the trailing edge portions 20b of the plurality of blades 20. The shroud 30 does not cover the leading edge portions 20a of the plurality of blades 20 in the Z direction. The shroud 30 may not have a surface overlapping the rotation axis AX in the Z direction.

[0024] As the main board 10 rotates, the plurality of blades 20 and the shield 30 rotate together with the main board 10. Figure 1 As shown by arrow A, air is introduced along the Z direction. Figure 1 As indicated by the arrow B in the middle, a flow (airflow) of air is generated from between the shroud 30 and the main plate 10 toward the outside of the centrifugal blower 100 along the XY plane.

[0025] Hereinafter, the plurality of blades 20 will be described in more detail.

[0026] Figure 2 It is a top view showing the centrifugal blower according to the embodiment.

[0027] exist Figure 2In the figure, the shield 30 is omitted.

[0028] like Figure 2 As shown, the plurality of blades 20 include a first blade 21 , a second blade 22 , and a third blade 23 .

[0029] The first blade 21 has a first leading edge 21a and a first trailing edge 21b. The first leading edge 21a is an end portion on the central portion 10a side. The first trailing edge 21b is an end portion on the peripheral portion 10b side. The length from the first leading edge 21a to the first trailing edge 21b is a first length L1.

[0030] The second blade 22 has a second leading edge 22a and a second trailing edge 22b. The second leading edge 22a is an end portion on the central portion 10a side. The second trailing edge 22b is an end portion on the peripheral portion 10b side. The length from the second leading edge 22a to the second trailing edge 22b is a second length L2. The second length L2 is longer than the first length L1.

[0031] The third blade 23 has a third leading edge 23a and a third trailing edge 23b. The third leading edge 23a is an end portion on the central portion 10a side. The third trailing edge 23b is an end portion on the peripheral portion 10b side. The length from the third leading edge 23a to the third trailing edge 23b is a third length L3. The third length L3 is longer than the second length L2.

[0032] The first length L1 is, for example, 0.9 times or less, preferably 0.5 times or more and 0.8 times or less of the second length L2. The third length L3 is, for example, 1.1 times or more, preferably 1.2 times or more and 2.0 times or less of the second length L2.

[0033] As described above, in the centrifugal fan 100 of the embodiment, three types of blades 20 (the first blade 21, the second blade 22, and the third blade 23) having different lengths from the front edge portion 20a to the rear edge portion 20b are provided.

[0034] In the centrifugal blower 100 of the embodiment, the first blade 21, the second blade 22, and the third blade 23 are arranged in the rotation direction RD in the order of the first blade 21, the second blade 22, and the third blade 23. In this example, in the rotation direction RD, a group of three types of blades 20 arranged in the order of the first blade 21, the second blade 22, and the third blade 23 is provided.

[0035] The number of the first blades 21, the number of the second blades 22, and the number of the third blades 23 are respectively the same. In addition, the total number of the plurality of blades 20 is a multiple of 3 that is greater than or equal to 6. That is, the number of the first blades 21, the number of the second blades 22, and the number of the third blades 23 are, for example, greater than or equal to 2. In this example, three first blades 21, three second blades 22, and three third blades 23 are provided. That is, in this example, the total number of the plurality of blades 20 is 9. The total number of the plurality of blades 20 is preferably an odd number.

[0036] In addition, when viewed from the direction along the Z direction, the length of the first blade 21 in the extension direction of the first blade 21 (i.e., the direction from the first leading edge portion 21a along the first blade 21 toward the first trailing edge portion 21b) is shorter than the length of the second blade 22 in the extension direction of the second blade 22 (i.e., the direction from the second leading edge portion 22a along the second blade 22 toward the second trailing edge portion 22b) when viewed from the direction along the Z direction, and is shorter than the length of the third blade 23 in the extension direction of the third blade 23 (i.e., the direction from the third leading edge portion 23a along the third blade 23 toward the third trailing edge portion 23b) when viewed from the direction along the Z direction. The length of each blade in the extension direction is represented by, for example, the length of the center line between one surface (the surface to which positive pressure is applied during rotation) and the other surface (the surface to which negative pressure is applied during rotation) in the cross section of each blade along the Z direction.

[0037] By providing three types of blades 20 (first blade 21, second blade 22, and third blade 23) having different lengths from the leading edge 20a to the trailing edge 20b, for example, the blades are less likely to become heavier than when all blades are provided as the third blade 23. Thus, vibration during rotation can be suppressed. In addition, compared with when all blades are provided as the third blade 23, an increase in the cost of materials can be suppressed.

[0038] In addition, the first blade 21, the second blade 22, and the third blade 23 are arranged in the order of the first blade 21, the second blade 22, and the third blade 23 in the rotation direction RD, thereby, for example, compared with the case where the third blade 23, the second blade 22, and the first blade 21 are arranged in the order of the third blade 23, the second blade 22, and the first blade 21 in the rotation direction RD, the flow path between the second blade 22 and the third blade 23 is less likely to be narrowed, and therefore, in the flow path between the second blade 22 and the third blade 23, the flow path resistance is less likely to become large. As a result, the static pressure can be increased. In addition, the first blade 21, the second blade 22, and the third blade 23 are arranged in the order of the first blade 21, the second blade 22, and the third blade 23 in the rotation direction RD, thereby, for example, especially when the air volume is relatively small (for example, at 1500-1750m 3 / h range), can increase the static pressure.

[0039] In addition, by setting the total number of the plurality of blades 20 to an odd number, the generation of periodic noise (Nz sound) can be suppressed compared to the case where the total number of the plurality of blades 20 is set to an even number. In addition, by setting the total number of the plurality of blades 20 to 9, the static pressure can be increased compared to the case where the total number of the plurality of blades 20 is set to 6 or 12.

[0040] Hereinafter, the arrangement angles of the first blade 21 , the second blade 22 , and the third blade 23 will be described in more detail.

[0041] Figure 3 It is a top view showing the centrifugal blower according to the embodiment.

[0042] exist Figure 3 In the figure, the shield 30 is omitted.

[0043] like Figure 3 As shown, a straight line connecting the rotation axis AX and the first trailing edge 21b of the first blade 21 is set as a first imaginary line IL1. A straight line connecting the rotation axis AX and the second trailing edge 22b of the second blade 22 is set as a second imaginary line IL2. A straight line connecting the rotation axis AX and the third trailing edge 23b of the third blade 23 is set as a third imaginary line IL3.

[0044] Furthermore, the angle (minor angle) between the first imaginary line IL1 and the second imaginary line IL2 adjacent to each other is set as the first configuration angle θ1. The angle (minor angle) between the second imaginary line IL2 and the third imaginary line IL3 adjacent to each other is set as the second configuration angle θ2. The angle (minor angle) between the third imaginary line IL3 adjacent to each other and the first imaginary line IL1 is set as the third configuration angle θ3.

[0045] In the centrifugal blower 100 of the embodiment, for example, the third configuration angle θ3 is greater than at least one of the first configuration angle θ1 and the second configuration angle θ2. For example, when the third configuration angle θ3 is greater than the first configuration angle θ1, the third configuration angle θ3 may be greater than the second configuration angle θ2, may be the same as the second configuration angle θ2, or may be smaller than the second configuration angle θ2. For example, when the third configuration angle θ3 is greater than the second configuration angle θ2, the third configuration angle θ3 may be greater than the first configuration angle θ1, may be the same as the first configuration angle θ1, or may be smaller than the first configuration angle θ1. The second configuration angle θ2 may be greater than the first configuration angle θ1, may be the same as the first configuration angle θ1, or may be smaller than the first configuration angle θ1. In this example, the third configuration angle θ3 is greater than the first configuration angle θ1, and greater than the second configuration angle θ2. In addition, in this example, the second configuration angle θ2 is greater than the first configuration angle θ1.

[0046] When the third configuration angle θ3 is greater than the first configuration angle θ1, the difference between the third configuration angle θ3 and the first configuration angle θ1 is, for example, greater than 1° and less than 5°. When the third configuration angle θ3 is greater than the second configuration angle θ2, the difference between the third configuration angle θ3 and the second configuration angle θ2 is, for example, greater than 1° and less than 5°.

[0047] By making the third configuration angle θ3 larger than at least one of the first configuration angle θ1 and the second configuration angle θ2, the flow path between the first blade 21 and the third blade 23 is less likely to be narrowed compared to the case where the third configuration angle θ3 is set to be less than the first configuration angle θ1 and the case where the third configuration angle θ3 is set to be less than the second configuration angle θ2, so that the flow path resistance is less likely to be increased in the flow path between the first blade 21 and the third blade 23. As a result, the static pressure can be increased.

[0048] Hereinafter, the thicknesses of the first blade 21 , the second blade 22 , and the third blade 23 will be described in more detail.

[0049] Figure 4 It is a top view showing a part of the centrifugal blower according to the embodiment.

[0050] exist Figure 4 In the figure, the shield 30 is omitted.

[0051] like Figure 4 As shown, the maximum thickness of the first blade 21 is set to a first maximum thickness T1. The maximum thickness of the second blade 22 is set to a second maximum thickness T2. The maximum thickness of the third blade 23 is set to a third maximum thickness T3.

[0052] The first maximum thickness T1 is the maximum value of the thickness of the first blade 21 in the direction orthogonal to the extension direction of the first blade 21 (i.e., the direction from the first leading edge 21a along the first blade 21 toward the first trailing edge 21b) when viewed from the direction along the Z direction. The second maximum thickness T2 is the maximum value of the thickness of the second blade 22 in the direction orthogonal to the extension direction of the second blade 22 (i.e., the direction from the second leading edge 22a along the second blade 22 toward the second trailing edge 22b) when viewed from the direction along the Z direction. The third maximum thickness T3 is the maximum value of the thickness of the third blade 23 in the direction orthogonal to the extension direction of the third blade 23 (i.e., the direction from the third leading edge 23a along the third blade 23 toward the third trailing edge 23b) when viewed from the direction along the Z direction.

[0053] In the centrifugal blower 100 of the embodiment, for example, the first maximum thickness T1 is smaller than the second maximum thickness T2. In addition, the first maximum thickness T1 is, for example, smaller than the third maximum thickness T3. The second maximum thickness T2 may be larger than the third maximum thickness T3, may be the same as the third maximum thickness, or may be smaller than the third maximum thickness T3.

[0054] The difference between the first maximum thickness T1 and the second maximum thickness T2 is, for example, 0.1 mm or more and 5 mm or less. The difference between the first maximum thickness T1 and the third maximum thickness T3 is, for example, 0.1 mm or more and 5 mm or less.

[0055] For example, if the first configuration angle θ1 is reduced, the maximum pressure applied to the first blade 21 during rotation is smaller than the maximum pressure applied to the second blade 22 during rotation and the maximum pressure applied to the third blade 23 during rotation. Therefore, the first maximum thickness T1 can be made smaller than the second maximum thickness T2 and the third maximum thickness T3. By making the first maximum thickness T1 smaller than the second maximum thickness T2 and the third maximum thickness T3, for example, the cost of materials can be reduced.

[0056] Hereinafter, the heights of the first blade 21 , the second blade 22 , and the third blade 23 will be described in more detail.

[0057] Figure 5 It is a perspective view showing a centrifugal blower according to the embodiment.

[0058] like Figure 5 As shown, the maximum height of the first blade 21 is set to a first maximum height H1. The maximum height of the second blade 22 is set to a second maximum height H2. The maximum height of the third blade 23 is set to a third maximum height H3.

[0059] The first maximum height H1 is the maximum value of the length of the first blade 21 in the extending direction (Z direction) of the rotation axis AX. The second maximum height H2 is the maximum value of the length of the second blade 22 in the extending direction (Z direction) of the rotation axis AX. The third maximum height H3 is the maximum value of the length of the third blade 23 in the extending direction (Z direction) of the rotation axis AX.

[0060] In the centrifugal blower 100 of the embodiment, for example, the second maximum height H2 is smaller than the first maximum height H1. In addition, the third maximum height H3 is smaller than the first maximum height H1. The second maximum height H2 may be larger than the third maximum height H3, may be the same as the third maximum height H3, or may be smaller than the third maximum height H3.

[0061] The difference between the second maximum height H2 and the first maximum height H1 is, for example, 0.1 mm or more and 1 cm or less. The difference between the third maximum height H3 and the first maximum height H1 is, for example, 0.1 mm or more and 1 cm or less.

[0062] For example, at the side edge (end in the Z direction) of the second blade 22 and the side edge (end in the Z direction) of the third blade 23, airflow separation is likely to occur during rotation, and there is a possibility that the load becomes too large or pressure loss occurs. In contrast, by making the second maximum height H2 and the third maximum height H3 smaller than the first maximum height H1, airflow separation at the side edge of the second blade 22 and the side edge of the third blade 23 can be suppressed, and the load at the side edge of the second blade 22 and the side edge of the third blade 23 can be suppressed from becoming too large or pressure loss can be suppressed.

[0063] Hereinafter, the mounting angles of the first blade 21 , the second blade 22 , and the third blade 23 will be described in more detail.

[0064] Figure 6 It is a top view showing the centrifugal blower according to the embodiment.

[0065] exist Figure 6 In the figure, the shield 30 is omitted.

[0066] like Figure 6 As shown, a straight line connecting the rotation axis AX and the first trailing edge 21b of the first blade 21 is set as a first imaginary line IL1. A straight line connecting the rotation axis AX and the second trailing edge 22b of the second blade 22 is set as a second imaginary line IL2. A straight line connecting the rotation axis AX and the third trailing edge 23b of the third blade 23 is set as a third imaginary line IL3. A straight line connecting the first trailing edge 21b of the first blade 21 and the first leading edge 21a is set as a fourth imaginary line IL4. A straight line connecting the second trailing edge 22b of the second blade 22 and the second leading edge 22a is set as a fifth imaginary line IL5. A straight line connecting the third trailing edge 23b of the third blade 23 and the third leading edge 23a is set as a sixth imaginary line IL6.

[0067] Furthermore, the angle (minor angle) between the first imaginary line IL1 and the fourth imaginary line IL4 adjacent to each other is set as the first mounting angle φ1. The angle (minor angle) between the second imaginary line IL2 and the fifth imaginary line IL5 adjacent to each other is set as the second mounting angle φ2. The angle (minor angle) between the third imaginary line IL3 and the sixth imaginary line IL6 adjacent to each other is set as the third mounting angle φ3.

[0068] In the centrifugal blower 100 of the embodiment, for example, the third mounting angle φ3 is smaller than at least one of the first mounting angle φ1 and the second mounting angle φ2. For example, when the third mounting angle φ3 is smaller than the first mounting angle φ1, the third mounting angle φ3 may be larger than the second mounting angle φ2, may be the same as the second mounting angle φ2, or may be smaller than the second mounting angle φ2. For example, when the third mounting angle φ3 is smaller than the second mounting angle φ2, the third mounting angle φ3 may be larger than the first mounting angle φ1, may be the same as the first mounting angle φ1, or may be smaller than the first mounting angle φ1. The second mounting angle φ2 may be larger than the first mounting angle φ1, may be the same as the first mounting angle φ1, or may be smaller than the first mounting angle φ1. In this example, the third mounting angle φ3 is smaller than the first mounting angle φ1, and smaller than the second mounting angle φ2. In addition, in this example, the second mounting angle φ2 is the same as the first mounting angle φ1.

[0069] When the third mounting angle φ3 is smaller than the first mounting angle φ1, the difference between the third mounting angle φ3 and the first mounting angle φ1 is, for example, 1° or more and 5° or less. When the third mounting angle φ3 is smaller than the second mounting angle φ2, the difference between the third mounting angle φ3 and the second mounting angle φ2 is, for example, 1° or more and 5° or less.

[0070] By making the third mounting angle φ3 smaller than at least one of the first mounting angle φ1 and the second mounting angle φ2, the flow path between the first blade 21 and the third blade 23 is less likely to be narrowed, compared with the case where the third mounting angle φ3 is set to be greater than the first mounting angle φ1 or the case where the third mounting angle φ3 is set to be greater than the second mounting angle φ2. Therefore, the flow path resistance is less likely to increase in the flow path between the first blade 21 and the third blade 23. As a result, the static pressure can be increased.

[0071] The embodiment may also include the following configurations.

[0072] (Composition 1)

[0073] A centrifugal blower, comprising:

[0074] The main board rotates around the rotation axis;

[0075] Shield; and

[0076] A plurality of blades are arranged between the main board and the shield;

[0077] The main board has a central portion and a peripheral portion, wherein the peripheral portion is located outside the central portion.

[0078] The plurality of blades include a first blade, a second blade, and a third blade.

[0079] The first blade has a first leading edge portion as an end portion on the side of the central portion and a first trailing edge portion as an end portion on the side of the outer peripheral portion.

[0080] The second blade has a second leading edge portion which is an end portion on the side of the central portion, and a second trailing edge portion which is an end portion on the side of the outer peripheral portion.

[0081] The third blade has a third leading edge portion which is an end portion on the central portion side and a third trailing edge portion which is an end portion on the peripheral portion side.

[0082] When the length from the first front edge to the first rear edge is set as the first length, the length from the second front edge to the second rear edge is set as the second length, and the length from the third front edge to the third rear edge is set as the third length,

[0083] The second length is greater than the first length,

[0084] The third length is greater than the second length.

[0085] The number of the first blades, the number of the second blades, and the number of the third blades are respectively the same,

[0086] The first blade, the second blade, and the third blade are arranged in the order of the first blade, the second blade, and the third blade in the rotation direction.

[0087] (Composition 2)

[0088] In the centrifugal blower described in configuration 1,

[0089] When a straight line connecting the rotation axis and the first rear edge is set as a first imaginary line, a straight line connecting the rotation axis and the second rear edge is set as a second imaginary line, a straight line connecting the rotation axis and the third rear edge is set as a third imaginary line, an angle between the first imaginary line and the second imaginary line adjacent to each other is set as a first configuration angle, an angle between the second imaginary line and the third imaginary line adjacent to each other is set as a second configuration angle, and an angle between the third imaginary line and the first imaginary line adjacent to each other is set as a third configuration angle,

[0090] The third arrangement angle is larger than at least any one of the first arrangement angle and the second arrangement angle.

[0091] (Composition 3)

[0092] In the centrifugal blower described in Configuration 1 or Configuration 2,

[0093] When the maximum thickness of the first blade in a direction perpendicular to the extension direction of the first blade is set as the first maximum thickness, the maximum thickness of the second blade in a direction perpendicular to the extension direction of the second blade is set as the second maximum thickness, and the maximum thickness of the third blade in a direction perpendicular to the extension direction of the third blade is set as the third maximum thickness,

[0094] The first maximum thickness is smaller than the second maximum thickness,

[0095] The first maximum thickness is smaller than the third maximum thickness.

[0096] (Composition 4)

[0097] In the centrifugal blower according to any one of configurations 1 to 3,

[0098] When the maximum height of the first blade in the extending direction of the rotating shaft is set as the first maximum height, the maximum height of the second blade in the extending direction of the rotating shaft is set as the second maximum height, and the maximum height of the third blade in the extending direction of the rotating shaft is set as the third maximum height,

[0099] The second maximum height is smaller than the first maximum height.

[0100] The third maximum height is smaller than the first maximum height.

[0101] (Composition 5)

[0102] In the centrifugal blower according to any one of configurations 1 to 4,

[0103] When a straight line connecting the rotation axis and the first rear edge is set as a first imaginary line, a straight line connecting the rotation axis and the second rear edge is set as a second imaginary line, a straight line connecting the rotation axis and the third rear edge is set as a third imaginary line, a straight line connecting the first rear edge and the first front edge is set as a fourth imaginary line, a straight line connecting the second rear edge and the second front edge is set as a fifth imaginary line, a straight line connecting the third rear edge and the third front edge is set as a sixth imaginary line, an angle between the first imaginary line and the fourth imaginary line adjacent to each other is set as a first installation angle, an angle between the second imaginary line and the fifth imaginary line adjacent to each other is set as a second installation angle, and an angle between the third imaginary line and the sixth imaginary line adjacent to each other is set as a third installation angle,

[0104] The third mounting angle is smaller than at least any one of the first mounting angle and the second mounting angle.

[0105] As described above, according to the embodiment, there is provided a centrifugal blower capable of suppressing vibration during rotation, improving static pressure, and suppressing an increase in material cost.

[0106] The above examples illustrate the embodiments of the present invention, which are presented as examples and are not intended to limit the scope of the invention. The new embodiments can be implemented in various other ways, and various omissions, substitutions, changes, etc. can be made without departing from the scope of the invention. The embodiments and their variations are included in the scope and purpose of the invention, and are included in the invention described in the technical solution and the scope equivalent thereto.

Claims

1. A centrifugal blower, comprising: The main board rotates around the rotation axis; Shield; and A plurality of blades are arranged between the main board and the shield; The main board has a central portion and a peripheral portion, wherein the peripheral portion is located outside the central portion. The plurality of blades include a first blade, a second blade, and a third blade. The first blade has a first leading edge portion as an end portion on the side of the central portion and a first trailing edge portion as an end portion on the side of the outer peripheral portion. The second blade has a second leading edge portion which is an end portion on the side of the central portion, and a second trailing edge portion which is an end portion on the side of the outer peripheral portion. The third blade has a third leading edge portion which is an end portion on the central portion side and a third trailing edge portion which is an end portion on the peripheral portion side. When the length from the first front edge to the first rear edge is set as the first length, the length from the second front edge to the second rear edge is set as the second length, and the length from the third front edge to the third rear edge is set as the third length, The second length is greater than the first length, The third length is greater than the second length. The number of the first blades, the number of the second blades, and the number of the third blades are respectively the same, The total number of the plurality of blades is a multiple of 3 that is greater than 6, The first blade, the second blade, and the third blade are arranged in the order of the first blade, the second blade, and the third blade in the rotation direction.

2. The centrifugal blower according to claim 1, wherein: When a straight line connecting the rotation axis and the first rear edge is set as a first imaginary line, a straight line connecting the rotation axis and the second rear edge is set as a second imaginary line, a straight line connecting the rotation axis and the third rear edge is set as a third imaginary line, an angle between the first imaginary line and the second imaginary line adjacent to each other is set as a first configuration angle, an angle between the second imaginary line and the third imaginary line adjacent to each other is set as a second configuration angle, and an angle between the third imaginary line and the first imaginary line adjacent to each other is set as a third configuration angle, The third arrangement angle is larger than at least any one of the first arrangement angle and the second arrangement angle.

3. The centrifugal blower according to claim 1, wherein: When the maximum thickness of the first blade in a direction perpendicular to the extension direction of the first blade is set as the first maximum thickness, the maximum thickness of the second blade in a direction perpendicular to the extension direction of the second blade is set as the second maximum thickness, and the maximum thickness of the third blade in a direction perpendicular to the extension direction of the third blade is set as the third maximum thickness, The first maximum thickness is smaller than the second maximum thickness, The first maximum thickness is smaller than the third maximum thickness.

4. The centrifugal blower according to claim 1, wherein: When the maximum height of the first blade in the extending direction of the rotating shaft is set as the first maximum height, the maximum height of the second blade in the extending direction of the rotating shaft is set as the second maximum height, and the maximum height of the third blade in the extending direction of the rotating shaft is set as the third maximum height, The second maximum height is smaller than the first maximum height. The third maximum height is smaller than the first maximum height.

5. The centrifugal blower according to any one of claims 1 to 4, wherein: When a straight line connecting the rotation axis and the first rear edge is set as a first imaginary line, a straight line connecting the rotation axis and the second rear edge is set as a second imaginary line, a straight line connecting the rotation axis and the third rear edge is set as a third imaginary line, a straight line connecting the first rear edge and the first front edge is set as a fourth imaginary line, a straight line connecting the second rear edge and the second front edge is set as a fifth imaginary line, a straight line connecting the third rear edge and the third front edge is set as a sixth imaginary line, an angle between the first imaginary line and the fourth imaginary line adjacent to each other is set as a first installation angle, an angle between the second imaginary line and the fifth imaginary line adjacent to each other is set as a second installation angle, and an angle between the third imaginary line and the sixth imaginary line adjacent to each other is set as a third installation angle, The third mounting angle is smaller than at least any one of the first mounting angle and the second mounting angle.

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