Centrifugal blower

Abstract

To provide a centrifugal blower which enhances a static pressure while suppressing vibration during rotation, and which can suppress increase in cost required for materials.SOLUTION: A centrifugal blower includes: a main plate rotating around a rotary shaft; a shroud; and a plurality of blades provided between the main plate and the shroud. The plurality of blades include first to third blades. The first blade includes a first front edge part and a first rear edge part. The second blade includes a second front edge part and a second rear edge part. The third blade includes a third front edge part and a third rear edge part. When the length from the first front edge part to the first rear edge part is defined as a first length, a length from the second front edge part to the second rear edge part is defined as a second length, and a length from the third front edge part to the third rear edge part is defined as a third length, the second length is greater than the first length, the third length is greater than the second length, the first to third blades are equal in number, and the total number of the plurality of blades is a multiple of 3 equal to or greater than 6. The first to third blades are arranged in the order of the first blade, the second blade, and the third blade in the rotation direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] It is known that centrifugal blowers are used in heat exchangers and the like. In such centrifugal blowers, it is necessary to increase the static pressure, which corresponds to the pressure difference before and after passing through the centrifugal blower. Increasing the length of the blades is considered as a means of increasing the static pressure. However, increasing the length of the blades makes the blades heavier, which may cause vibrations during rotation. In addition, increasing the length of the blades may increase the cost of materials. [Prior art documents] [Non-patent literature]

[0003] [Patent Document 1] JP 2017-125408 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a centrifugal blower that can increase static pressure while suppressing vibration during rotation, and can also suppress an increase in material costs. [Means for solving the problem]

[0005] A centrifugal blower according to an embodiment includes a main plate that rotates around a rotation axis, a shroud, and a plurality of blades provided between the main plate and the shroud. The plurality of blades include a first blade, a second blade, and a third blade. The first blade has a first leading edge portion that is an end portion on the central portion side, and a first trailing edge portion that is an end portion on the outer peripheral portion side. The second blade has a second leading edge portion that is an end portion on the central portion side, and a second trailing edge portion that is an end portion on the outer peripheral portion side. The third blade has a third leading edge portion that is an end portion on the central portion side, and a third trailing edge portion that is an end portion on the outer peripheral portion side. When a length from the first leading edge portion to the first trailing edge portion is defined as a first length, a length from the second leading edge portion to the second trailing edge portion is defined as a second length, and a length from the third leading edge portion to the third trailing edge portion is defined as a 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 the same. The total number of the plurality of blades is a multiple of 3 that is equal to or greater than 6, and the first blades, the second blades, and the third blades are arranged in this order in the direction of rotation: the first blade, the second blade, and the third blade. [Brief description of the drawings]

[0006] [Figure 1] 1 is a perspective view illustrating a centrifugal blower according to an embodiment. [Diagram 2] FIG. 1 is a plan view illustrating a centrifugal blower according to an embodiment. [Diagram 3] FIG. 1 is a plan view illustrating a centrifugal blower according to an embodiment. [Figure 4] FIG. 2 is a plan view illustrating a portion of the centrifugal blower according to the embodiment. [Diagram 5] 1 is a perspective view illustrating a centrifugal blower according to an embodiment. [Figure 6] FIG. 1 is a plan view illustrating a centrifugal blower according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Even when the same part is shown, the dimensions and ratios of each part may be different depending on the drawing. In this specification and each drawing, elements similar to those described above with reference to the previous drawings are given the same reference numerals and detailed descriptions thereof will be omitted as appropriate.

[0008] FIG. 1 is a perspective view illustrating a centrifugal blower according to an embodiment. As shown in FIG. 1, a centrifugal blower 100 according to the embodiment includes a main plate 10, a plurality of blades 20, and a shroud 30.

[0009] The main plate 10 rotates in a rotation direction RD around a rotation axis AX. The rotation axis extends along the Z direction. The main plate 10 rotates along an XY plane perpendicular to the Z direction. The XY plane is a plane along an X direction perpendicular to the Z direction and a Y direction perpendicular to the Z direction and the X direction. In this example, the rotation direction RD is counterclockwise in the direction from the shroud 30 toward the main plate 10.

[0010] The main plate 10 has a central portion 10a and an outer peripheral portion 10b. The central portion 10a includes an intersection of the rotation axis AX and the main plate 10. The central portion 10a protrudes in the Z direction. The outer peripheral portion 10b is located outside the central portion 10a. The outer peripheral portion 10b extends along the XY plane.

[0011] The multiple blades 20 are provided between the main plate 10 and the shroud 30. The multiple blades 20 are interposed between the main plate 10 and the shroud 30. The multiple blades 20 are provided, for example, along the Z direction. The multiple blades 20 may be provided, for example, so as to be inclined with respect to the Z direction.

[0012] Each of the blades 20 extends from the central portion 10a of the main plate 10 toward the outer periphery 10b. Each of the blades 20 has a leading edge 20a which is an end portion on the central portion 10a side, and a trailing edge 20b which is an end portion on the outer periphery 10b side. For example, each of the blades 20 extends in a curved manner from the leading edge 20a toward the trailing edge 20b. For example, each of the blades 20 may extend linearly from the leading edge 20a toward the trailing edge 20b.

[0013] The shroud 30 covers the trailing edge portions 20b of the blades 20 in the Z direction. The trailing edge portions 20b of the blades 20 are located between the main plate 10 and the shroud 30 in the Z direction. The shroud 30 is connected to the trailing edge portions 20b of the blades 20. The shroud 30 does not cover the leading edge portions 20a of the blades 20 in the Z direction. The shroud 30 does not have a surface that overlaps with the rotation axis AX in the Z direction.

[0014] As the main plate 10 rotates, the multiple blades 20 and the shroud 30 rotate together with the main plate 10. As a result, the multiple blades 20 take in air along the Z direction as indicated by arrow A in Fig. 1, and generate an air flow (air current) from between the shroud 30 and the main plate 10 toward the outside of the centrifugal blower 100 along the XY plane as indicated by arrow B in Fig. 1.

[0015] The blades 20 will be described in more detail below. FIG. 2 is a plan view illustrating the centrifugal blower according to the embodiment. In FIG. 2, the shroud 30 is omitted. As shown in FIG. 2, the plurality of blades 20 include a first blade 21, a second blade 22, and a third blade 23.

[0016] The first blade 21 has a first leading edge portion 21a and a first trailing edge portion 21b. The first leading edge portion 21a is an end portion on the central portion 10a side. The first trailing edge portion 21b is an end portion on the outer peripheral portion 10b side. The length from the first leading edge portion 21a to the first trailing edge portion 21b is a first length L1.

[0017] The second blade 22 has a second leading edge portion 22a and a second trailing edge portion 22b. The second leading edge portion 22a is an end portion on the central portion 10a side. The second trailing edge portion 22b is an end portion on the outer peripheral portion 10b side. The length from the second leading edge portion 22a to the second trailing edge portion 22b is a second length L2. The second length L2 is longer than the first length L1.

[0018] The third blade 23 has a third leading edge portion 23a and a third trailing edge portion 23b. The third leading edge portion 23a is an end portion on the central portion 10a side. The third trailing edge portion 23b is an end portion on the outer peripheral portion 10b side. The length from the third leading edge portion 23a to the third trailing edge portion 23b is a third length L3. The third length L3 is longer than the second length L2.

[0019] The first length L1 is, for example, 0.9 times or less, preferably 0.5 to 0.8 times, the second length L2. The third length L3 is, for example, 1.1 times or more, preferably 1.2 to 2.0 times, the second length L2.

[0020] In this manner, the centrifugal blower 100 according to the embodiment is provided with three types of blades 20 (first blade 21, second blade 22, and third blade 23) that are different from one another in length from the leading edge portion 20a to the trailing edge portion 20b.

[0021] In the centrifugal blower 100 according to this 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, three sets of three types of blades 20 are provided, each set having the first blade 21, the second blade 22, and the third blade 23 arranged in the rotation direction RD in that order.

[0022] The number of first blades 21, the number of second blades 22, and the number of third blades 23 are the same. Moreover, the total number of the plurality of blades 20 is a multiple of 3 that is 6 or more. 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, 2 or more, respectively. 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. It is preferable that the total number of the plurality of blades 20 is an odd number.

[0023] When viewed in the Z direction, the length of the first blade 21 in the direction in which the first blade 21 extends (i.e., the direction from the first leading edge 21a along the first blade 21 toward the first trailing edge 21b) is shorter than the length of the second blade 22 in the direction in which the second blade 22 extends (i.e., the direction from the second leading edge 22a along the second blade 22 toward the second trailing edge 22b) when viewed in the Z direction, and is shorter than the length of the third blade 23 in the direction in which the third blade 23 extends (i.e., the direction from the third leading edge 23a along the third blade 23 toward the third trailing edge 23b) when viewed in the Z direction. The length of each blade in the direction in which it extends is represented, for example, by the length of the center line between one surface (a surface to which positive pressure is applied during rotation) and the other surface (a surface to which negative pressure is applied during rotation) in a cross section of each blade along the Z direction.

[0024] By providing three types of blades 20 (first blade 21, second blade 22, and third blade 23) with different lengths from the leading edge 20a to the trailing edge 20b, the blades are less likely to become heavy compared to, for example, a case in which all the blades are the third blades 23. This makes it possible to suppress vibration during rotation. Also, compared to a case in which all the blades are the third blades 23, it is possible to suppress an increase in material costs.

[0025] In addition, by arranging the first blade 21, the second blade 22, and the third blade 23 in the rotation direction RD in this order, the flow path between the second blade 22 and the third blade 23 is less likely to become narrower than when, for example, the third blade 23, the second blade 22, and the first blade 21 are arranged in this order in the rotation direction RD, and therefore flow path resistance is less likely to increase in the flow path between the second blade 22 and the third blade 23. This makes it possible to increase the static pressure. In addition, by arranging the first blade 21, the second blade 22, and the third blade 23 in the rotation direction RD in this order, for example, particularly when the air volume is relatively small (for example, 1500 to 1750 m 3 / h), the static pressure can be increased.

[0026] In addition, by making the total number of the plurality of blades 20 an odd number, it is possible to suppress the generation of periodic noise (Nz sound) compared to when the total number of the plurality of blades 20 is an even number. In addition, by making the total number of the plurality of blades 20 nine, it is possible to increase the static pressure compared to when the total number of the plurality of blades 20 is six or twelve.

[0027] The arrangement angles of the first blade 21, the second blade 22, and the third blade 23 will be described in more detail below. FIG. 3 is a plan view illustrating the centrifugal blower according to the embodiment. In FIG. 3, the shroud 30 is omitted. 3, a straight line connecting the rotation axis AX and the first trailing edge 21b of the first blade 21 is defined 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 defined 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 defined as a third imaginary line IL3.

[0028] The angle (minor angle) between the first virtual line IL1 and the second virtual line IL2 that are adjacent to each other is defined as a first arrangement angle θ1. The angle (minor angle) between the second virtual line IL2 and the third virtual line IL3 that are adjacent to each other is defined as a second arrangement angle θ2. The angle (minor angle) between the third virtual line IL3 and the first virtual line IL1 that are adjacent to each other is defined as a third arrangement angle θ3.

[0029] In the centrifugal blower 100 according to the embodiment, for example, the third arrangement angle θ3 is greater than at least one of the first arrangement angle θ1 and the second arrangement angle θ2. For example, when the third arrangement angle θ3 is greater than the first arrangement angle θ1, the third arrangement angle θ3 may be greater than the second arrangement angle θ2, may be the same as the second arrangement angle θ2, or may be smaller than the second arrangement angle θ2. For example, when the third arrangement angle θ3 is greater than the second arrangement angle θ2, the third arrangement angle θ3 may be greater than the first arrangement angle θ1, may be the same as the first arrangement angle θ1, or may be smaller than the first arrangement angle θ1. The second arrangement angle θ2 may be greater than the first arrangement angle θ1, may be the same as the first arrangement angle θ1, or may be smaller than the first arrangement angle θ1. In this example, the third arrangement angle θ3 is greater than the first arrangement angle θ1 and greater than the second arrangement angle θ2. Also, in this example, the second arrangement angle θ2 is greater than the first arrangement angle θ1.

[0030] When the third arrangement angle θ3 is greater than the first arrangement angle θ1, the difference between the third arrangement angle θ3 and the first arrangement angle θ1 is, for example, 1° to 5°. When the third arrangement angle θ3 is greater than the second arrangement angle θ2, the difference between the third arrangement angle θ3 and the second arrangement angle θ2 is, for example, 1° to 5°.

[0031] By making the third arrangement angle θ3 larger than at least one of the first arrangement angle θ1 and the second arrangement angle θ2, the flow path between the first blade 21 and the third blade 23 is less likely to narrow compared to when the third arrangement angle θ3 is equal to or smaller than the first arrangement angle θ1 or when the third arrangement angle θ3 is equal to or smaller than the second arrangement angle θ2, and therefore flow path resistance is less likely to increase in the flow path between the first blade 21 and the third blade 23. This makes it possible to increase the static pressure.

[0032] The thicknesses of the first blade 21, the second blade 22, and the third blade 23 will be described in more detail below. FIG. 4 is a plan view illustrating a part of the centrifugal blower according to the embodiment. In FIG. 4, the shroud 30 is omitted. 4, the maximum thickness of the first blade 21 is defined as a first maximum thickness T1, the maximum thickness of the second blade 22 is defined as a second maximum thickness T2, and the maximum thickness of the third blade 23 is defined as a third maximum thickness T3.

[0033] The first maximum thickness T1 is the maximum thickness of the first blade 21 in a direction perpendicular to the direction in which the first blade 21 extends (i.e., from the first leading edge 21a along the first blade 21 toward the first trailing edge 21b) when viewed along the Z direction. The second maximum thickness T2 is the maximum thickness of the second blade 22 in a direction perpendicular to the direction in which the second blade 22 extends (i.e., from the second leading edge 22a along the second blade 22 toward the second trailing edge 22b) when viewed along the Z direction. The third maximum thickness T3 is the maximum thickness of the third blade 23 in a direction perpendicular to the direction in which the third blade 23 extends (i.e., from the third leading edge 23a along the third blade 23 toward the third trailing edge 23b) when viewed along the Z direction.

[0034] In the centrifugal blower 100 according to the embodiment, for example, the first maximum thickness T1 is smaller than the second maximum thickness T2. Also, the first maximum thickness T1 is 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.

[0035] 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.

[0036] For example, when the above-mentioned first arrangement angle θ1 is reduced, the maximum pressure applied to the first blade 21 during rotation becomes 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.

[0037] The heights of the first blade 21, the second blade 22, and the third blade 23 will be described in more detail below. FIG. 5 is a perspective view illustrating a centrifugal blower according to the embodiment. 5, the maximum height of the first blade 21 is defined as a first maximum height H1, the maximum height of the second blade 22 is defined as a second maximum height H2, and the maximum height of the third blade 23 is defined as a third maximum height H3.

[0038] The first maximum height H1 is the maximum length of the first blade 21 in the direction in which the rotation axis AX extends (Z direction). The second maximum height H2 is the maximum length of the second blade 22 in the direction in which the rotation axis AX extends (Z direction). The third maximum height H3 is the maximum length of the third blade 23 in the direction in which the rotation axis AX extends (Z direction).

[0039] In the centrifugal blower 100 according to this embodiment, for example, the second maximum height H2 is smaller than the first maximum height H1. Also, 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.

[0040] 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.

[0041] For example, at the side edge portions (end portions in the Z direction) of the second blades 22 and the side edge portions (end portions in the Z direction) of the third blades 23, airflow separation is likely to occur during rotation, which may result in excessive load and pressure loss. In response to this, by making the second maximum height H2 and the second maximum height H3 smaller than the first maximum height H1, airflow separation at the side edge portions of the second blades 22 and the side edge portions of the third blades 23 is suppressed, and excessive load and pressure loss at the side edge portions of the second blades 22 and the side edge portions of the third blades 23 can be suppressed.

[0042] The mounting angles of the first blade 21, the second blade 22, and the third blade 23 will be described in more detail below. FIG. 6 is a plan view illustrating the centrifugal blower according to the embodiment. In FIG. 6, the shroud 30 is omitted. As shown in FIG. 6, the straight line connecting the rotation axis AX and the first rear edge portion 21b of the first blade 21 is defined as the first imaginary line IL1. The straight line connecting the rotation axis AX and the second rear edge portion 22b of the second blade 22 is defined as the second imaginary line IL2. The straight line connecting the rotation axis AX and the third rear edge portion 23b of the third blade 23 is defined as the third imaginary line IL3. The straight line connecting the first rear edge portion 21b and the first leading edge portion 21a of the first blade 21 is defined as the fourth imaginary line IL4. The straight line connecting the second rear edge portion 22b and the second leading edge portion 22a of the second blade 22 is defined as the fifth imaginary line IL5. The straight line connecting the third rear edge portion 23b and the third leading edge portion 23a of the third blade 23 is defined as the sixth imaginary line IL6.

[0043] The angle (minor angle) between the first virtual line IL1 and the fourth virtual line IL4, which are adjacent to each other, is defined as the first attachment angle φ1. The angle (minor angle) between the second virtual line IL2 and the fifth virtual line IL5, which are adjacent to each other, is defined as the second attachment angle φ2. The angle (minor angle) between the third virtual line IL3 and the sixth virtual line IL6, which are adjacent to each other, is defined as the third attachment angle φ3.

[0044] In the centrifugal blower 100 according to 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. Also, in this example, the second mounting angle φ2 is the same as the first mounting angle φ1.

[0045] 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.

[0046] 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 passage between the first blade 21 and the third blade 23 is less likely to narrow compared to when the third mounting angle φ3 is equal to or larger than the first mounting angle φ1 or when the third mounting angle φ3 is equal to or larger than the second mounting angle φ2, and therefore flow passage resistance is less likely to increase in the flow passage between the first blade 21 and the third blade 23. This makes it possible to increase the static pressure.

[0047] The embodiment may include the following features.

[0048] (Configuration 1) A main plate that rotates around a rotation axis; The shroud, A plurality of blades provided between the main plate and the shroud; Equipped with The plurality of blades includes a first blade, a second blade, and a third blade, The first blade has a first leading edge portion which is an end portion on the central portion side and a first trailing edge portion which is an end portion on the outer circumferential portion side, the second blade has a second leading edge portion which is an end portion on the central portion side and a second trailing edge portion which is an end portion on the outer circumferential portion side, 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 outer circumferential portion side, When a length from the first leading edge portion to the first trailing edge portion is defined as a first length, a length from the second trailing edge portion to the second trailing edge portion is defined as a second length, and a length from the third trailing edge portion to the third trailing edge portion is defined as a 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 the same, The centrifugal blower, wherein the first blade, the second blade, and the third blade are arranged in this order in a rotational direction: the first blade, the second blade, and the third blade.

[0049] (Configuration 2) When a straight line connecting the rotation axis and the first rear edge portion is defined as a first virtual line, a straight line connecting the rotation axis and the second rear edge portion is defined as a second virtual line, a straight line connecting the rotation axis and the third rear edge portion is defined as a third virtual line, an angle between the first virtual line and the second virtual line that are adjacent to each other is defined as a first arrangement angle, an angle between the second virtual line and the third virtual line that are adjacent to each other is defined as a second arrangement angle, and an angle between the third virtual line and the first virtual line that are adjacent to each other is defined as a third arrangement angle, 2. The centrifugal blower according to configuration 1, wherein the third arrangement angle is greater than at least one of the first arrangement angle and the second arrangement angle.

[0050] (Configuration 3) When the maximum thickness of the first blade in a direction perpendicular to the extension direction of the first blade is defined as a first maximum thickness, the maximum thickness of the second blade in a direction perpendicular to the extension direction of the second blade is defined as a second maximum thickness, and the maximum thickness of the third blade in a direction perpendicular to the extension direction of the third blade is defined as a third maximum thickness, the first maximum thickness is less than the second maximum thickness; 3. The centrifugal blower of configuration 1 or 2, wherein the first maximum thickness is less than the third maximum thickness.

[0051] (Configuration 4) When the maximum height in the direction in which the rotation shaft extends is defined as a first maximum height of the first blade, the maximum height of the second blade in the direction in which the rotation shaft extends is defined as a second maximum height, and the maximum height of the third blade in the direction in which the rotation shaft extends is defined as a third maximum height, the second maximum height is less than the first maximum height; The centrifugal blower according to any one of configurations 1 to 3, wherein the third maximum height is smaller than the first maximum height.

[0052] (Configuration 5) A straight line connecting the rotation axis and the first trailing edge portion is a first virtual line, a straight line connecting the rotation axis and the second trailing edge portion is a second virtual line, a straight line connecting the rotation axis and the third trailing edge portion is a third virtual line, a straight line connecting the first trailing edge portion and the first leading edge portion is a fourth virtual line, a straight line connecting the second trailing edge portion and the second leading edge portion is a fifth virtual line, a straight line connecting the third trailing edge portion and the third leading edge portion is a sixth virtual line, an angle between the first virtual line and the fourth virtual line adjacent to each other is a first mounting angle, an angle between the second virtual line and the fifth virtual line adjacent to each other is a second mounting angle, and an angle between the third virtual line and the sixth virtual line adjacent to each other is a third mounting angle, 5. The centrifugal blower according to any one of configurations 1 to 4, wherein the third mounting angle is smaller than at least one of the first mounting angle and the second mounting angle.

[0053] As described above, according to the embodiment, a centrifugal blower is provided that can increase static pressure while suppressing vibration during rotation, and can also suppress an increase in material costs.

[0054] Although the embodiment of the present invention has been illustrated above, this embodiment is presented as an example and is not intended to limit the scope of the invention. This new embodiment can be implemented in various other forms, and various omissions, substitutions, modifications, etc. can be made without departing from the gist of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0055] 10: Main plate 10a: Central part 10b: Outer periphery 20: Multiple wings 20a: Leading edge 20b: Trailing edge 21: First feather 21a: First leading edge 21b: 1st trailing edge 22: Second feather 22a: Second leading edge 22b: Second trailing edge 23: Third feather 23a: Third leading edge 23b: Third trailing edge 30: Shroud 100: Centrifugal blower AX: Rotation axis H1~H3: 1st~3rd maximum height IL1~IL6: 1st to 6th virtual lines L1~L3: 1st~3rd length RD: Rotation direction T1~T3: 1st~3rd maximum thickness θ1~θ3: 1st~3rd arrangement angle φ1~φ3: 1st~3rd installation angles

Claims

1. A main plate that rotates around a rotation axis; The shroud, A plurality of blades provided between the main plate and the shroud; Equipped with The plurality of blades includes a first blade, a second blade, and a third blade, The first blade has a first leading edge portion which is an end portion on the central portion side and a first trailing edge portion which is an end portion on the outer circumferential portion side, the second blade has a second leading edge portion which is an end portion on the central portion side and a second trailing edge portion which is an end portion on the outer circumferential portion side, 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 outer circumferential portion side, When a length from the first leading edge portion to the first trailing edge portion is defined as a first length, a length from the second leading edge portion to the second trailing edge portion is defined as a second length, and a length from the third leading edge portion to the third trailing edge portion is defined as a 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 the same, The total number of the plurality of blades is a multiple of 3 that is equal to or greater than 6, The centrifugal blower, wherein the first blade, the second blade, and the third blade are arranged in this order in a rotational direction: the first blade, the second blade, and the third blade.

2. When a straight line connecting the rotation axis and the first rear edge portion is defined as a first virtual line, a straight line connecting the rotation axis and the second rear edge portion is defined as a second virtual line, a straight line connecting the rotation axis and the third rear edge portion is defined as a third virtual line, an angle between the first virtual line and the second virtual line that are adjacent to each other is defined as a first arrangement angle, an angle between the second virtual line and the third virtual line that are adjacent to each other is defined as a second arrangement angle, and an angle between the third virtual line and the first virtual line that are adjacent to each other is defined as a third arrangement angle, The centrifugal blower according to claim 1 , wherein the third arrangement angle is greater than at least one of the first arrangement angle and the second arrangement angle.

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

4. When the maximum height in the direction in which the rotation shaft extends is defined as a first maximum height of the first blade, the maximum height of the second blade in the direction in which the rotation shaft extends is defined as a second maximum height, and the maximum height of the third blade in the direction in which the rotation shaft extends is defined as a third maximum height, the second maximum height is less than the first maximum height; The centrifugal blower of claim 1 , wherein the third maximum height is less than the first maximum height.

5. When a straight line connecting the rotation axis and the first rear edge portion is a first virtual line, a straight line connecting the rotation axis and the second rear edge portion is a second virtual line, a straight line connecting the rotation axis and the third rear edge portion is a third virtual line, a straight line connecting the first rear edge portion and the first front edge portion is a fourth virtual line, a straight line connecting the second rear edge portion and the second front edge portion is a fifth virtual line, a straight line connecting the third rear edge portion and the third front edge portion is a sixth virtual line, an angle between the first virtual line and the fourth virtual line adjacent to each other is a first mounting angle, an angle between the second virtual line and the fifth virtual line adjacent to each other is a second mounting angle, and an angle between the third virtual line and the sixth virtual line adjacent to each other is a third mounting angle, 5. The centrifugal blower according to claim 1, wherein the third mounting angle is smaller than at least one of the first mounting angle and the second mounting angle.

Images