centrifugal fan

Abstract

The centrifugal fan of the present invention suppresses the displacement of the center of gravity position associated with thermal deformation. The centrifugal fan (1) includes a first portion (40) provided on a rotor (5) and a second portion (50) provided on a fan portion (3), wherein the second portion (50) has a larger linear expansion coefficient than the first portion (40). The first portion (40) includes a first top portion (42) and a first cylindrical portion (43). The second portion (50) includes a second top portion (52) and a second cylindrical portion (53). The second cylindrical portion (53) includes an inner cylindrical surface (53f) that is opposed to the outer cylindrical surface (43f) of the first cylindrical portion (43) with a first gap (S1) therebetween. The first top portion (42) includes a first plane (42f), and the second top portion (52) includes a second plane (52f) that is opposed to the first plane (42f). A convex portion (60) is provided on the first top portion (42) or the second top portion (52). The first plane (42f) and the second plane (52f) are bonded and fixed by an adhesive (G) provided in a second gap (S2) formed by the convex portion (60).

Description

Technical Field

[0001] The invention relates to a centrifugal fan. Background Art

[0002] A centrifugal fan comprises a fan unit having multiple blades and a motor unit serving as a driving source for the fan unit. The fan unit draws fluid from near its center of rotation as it rotates and delivers it radially outward from the fan unit. Conventionally, a centrifugal fan employs a technique for securing the fan unit to the rotor of the motor unit, thereby rotating the rotor and fan unit together. For example, Patent Document 1 discloses a centrifugal fan in which the outer circumference of a metal rotor holder (rotor) provided on a motor (motor unit) is secured to the inner circumference of a blade support portion of a resin impeller (fan unit) using an adhesive.

[0003]

Prior technical literature

[0004] [Patent Literature]

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-116848 Summary of the Invention

[0006] [Problems to be solved by the invention]

[0007] However, when the outer circumferential surface of the rotor holder and the inner circumferential surface of the blade support portion of the fan unit are bonded together, as in Patent Document 1, the center of gravity may shift due to thermal deformation, depending on the centrifugal fan's operating environment. Thermal deformation refers to dimensional changes in the fan unit and the fixing member (in Patent Document 1, the rotor holder) that secures the fan unit, respectively, as a function of the fan's ambient temperature and temperature fluctuations. The fan unit and the fixing member are often made of different materials. For example, in Patent Document 1, the fan unit may be made of resin and the fixing member may be made of metal. Therefore, when the fan unit is made of a material with a larger linear expansion coefficient than the fixing member, the thermal deformation of the fan unit becomes greater than that of the fixing member. Consequently, the center of gravity of the fan unit relative to the fixing member may shift from its original position before thermal deformation. A shift in the center of gravity of the fan unit can adversely affect the fan's balance, potentially causing vibration and noise during operation.

[0008] The centrifugal fan of the present invention was developed in response to such a problem, and one of its purposes is to suppress the displacement of the center of gravity position associated with thermal deformation. It should be noted that this purpose is not limited to the present invention, and other purposes of the present invention include achieving effects derived from the various structures shown in the specific embodiments described below and not achievable with conventional technologies.

[0009]

Methods for solving the problem

[0010] The disclosed centrifugal fan can be implemented as the following embodiments (application examples) to solve at least a part of the above-mentioned problems.

[0011] The disclosed centrifugal fan comprises: a first portion provided on a rotor that rotates integrally with a shaft; and a second portion provided on a fan portion having a plurality of blades and fixed to the rotor, the second portion having a larger linear expansion coefficient than the first portion. The first portion comprises: a first top portion extending radially outward from a first hole through which the shaft passes and having a first flat surface facing a first axial direction of the shaft; and a first cylindrical portion extending from the radially outer end of the first top portion in a second axial direction opposite to the first axial direction. The second portion comprises: a second top portion located closer to the first axial direction than the first top portion, extending radially outward from a second hole through which the shaft passes and having a second flat surface opposite to the first flat surface; and a second cylindrical portion extending from the radially outer end of the second top portion in the second axial direction and having an inner cylindrical surface facing the outer cylindrical surface of the first cylindrical portion with a first gap therebetween. The first top surface portion is provided with a protrusion that protrudes in the first axial direction relative to the first plane and abuts against the second plane, or the second top surface portion is provided with a protrusion that protrudes in the second axial direction relative to the second plane and abuts against the first plane. The first plane and the second plane are bonded and fixed by an adhesive disposed in a second gap formed by the protrusion.

[0012] Effects of the invention

[0013] According to the disclosed centrifugal fan, it is possible to suppress the displacement of the center of gravity position due to thermal deformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is an axial cross-sectional view of the centrifugal fan according to the embodiment.

[0015] Figure 2 yes Figure 1 Magnified view of the X section.

[0016] Figure 3 is Figure 1 A perspective view of a rotor yoke provided on a rotor of a motor portion of a centrifugal fan.

[0017] Figure 4 is Figure 1 An axial half-section view of a main board with blades provided on the fan portion of a centrifugal fan.

[0018] Figure 5 From the second axis Figure 4 A three-dimensional image of the motherboard with blades. DETAILED DESCRIPTION

[0019] A centrifugal fan according to an embodiment will be described with reference to the accompanying drawings. The embodiments described below are merely illustrative and are not intended to exclude various modifications or technical applications not explicitly described in the following embodiments. The various structures of the present embodiment can be implemented with various modifications without departing from the scope of their main purpose.

[0020] [1. Summary]

[0021] Below, refer to Figure 1 and Figure 2 An overview of centrifugal fan 1 according to the present embodiment will be described below, and the structure of centrifugal fan 1 will be described in detail later. Figure 1 is an axial cross-sectional view of the centrifugal fan 1 of this embodiment. Figure 2 yes Figure 1 Magnified view of the X section.

[0022] like Figure 1 As shown, the centrifugal fan 1 includes a motor unit 2 serving as a drive source, and a fan unit 3 driven by the motor unit 2. The motor unit 2 includes a shaft 4, a rotor 5 that rotates integrally with the shaft 4, and a stator 6 disposed opposite the rotor 5. The fan unit 3 is an impeller that rotates coaxially with the shaft 4 and delivers fluid drawn in from the center of rotation to the outside (away from the center of rotation). The fan unit 3 has a plurality of blades 31. The fan unit 3 is mounted on one axial side of the shaft 4 (the first axial direction C1 side, described later) relative to the rotor 5 of the motor unit 2. The fan unit 3 is fixed to the rotor 5 so as to rotate integrally with the shaft 4 and the rotor 5.

[0023] Hereinafter, the direction in which the shaft 4 extends (the direction of the axis C of the shaft 4 ) is referred to as the axial direction. The axial direction in which the fan unit 3 is mounted relative to the rotor 5 of the motor unit 2 is referred to as the first axial direction C1, and the axial direction opposite to the first axial direction C1 is referred to as the second axial direction C2. Furthermore, the direction perpendicular to the axial direction and away from the axis C of the shaft 4 is referred to as the radially outward direction, while the direction in the same direction and toward the axis C is referred to as the radially inward direction. Unless otherwise specified, the term "radial direction" is simply used. The direction perpendicular to the axial direction and rotating about the axis C is referred to as the circumferential direction.

[0024] A first portion 40 is provided on the first axial direction C1 side of the rotor 5 within the rotor 5. A cup-shaped second portion 50, open toward the second axial direction C2, is provided on the second axial direction C2 side of the fan unit 3, which is mounted on the rotor 5 along the first axial direction C1. The second portion 50 is made of a material having a larger linear expansion coefficient than the first portion 40.

[0025] It should be noted that in this embodiment, as an example, the rotor yoke 9 of the rotor 5, which will be described later, corresponds to the first portion 40. Furthermore, the radially inner portion of the main plate portion 32 (both described later) of the main plate 13 with blades of the fan unit 3 is described as corresponding to the second portion 50. However, the first portion 40 may not be the rotor yoke 9, and the second portion 50 may not be part of the main plate 13 with blades. In the figures, to facilitate understanding of the correspondence between the parts and surfaces (elements) of the first portion 40 and the second portion 50 and the various structures of the specific examples, the reference numeral "40" representing the first portion is shown in parentheses, and the reference numerals representing the elements of the first portion 40 and the second portion 50 are shown in parentheses.

[0026] The first portion 40 includes a first top portion 42 extending radially outward from a first hole 41 through which the shaft 4 passes, and a cylindrical first barrel portion 43 extending from the radially outer end of the first top portion 42 toward the second axial direction C2. The first hole 41 forms a through-hole around the shaft 4 through which the shaft 4 passes. It should be noted that the term "extending toward..." is not limited to extending in a direction that is consistent with (parallel to) a reference direction (e.g., radial direction), but also includes extending in a direction that is inclined relative to the reference direction. This applies to the following description of "extending toward...".

[0027] The second portion 50 includes a second top surface portion 52 extending radially outward from a second hole portion 51 through which the shaft 4 passes, and a second cylindrical portion 53 extending in the second axial direction C2 from the radially outer end of the second top surface portion 52 (the boundary between the second top surface portion 52 and the main plate portion 32, described later). The second hole portion 51 is a portion around the shaft 4 that forms a through-hole through which the shaft 4 passes. The second top surface portion 52 is positioned closer to the first axial direction C1 than the first top surface portion 42. The second cylindrical portion 53 is radially outward from the first cylindrical portion 43 and axially located at the same position as the first cylindrical portion 43 (overlapping with the first cylindrical portion 43 when viewed radially). In other words, the second portion 50 is arranged to cover the first portion 40 from the radially outer side and the first axial direction C1.

[0028] like Figure 2 As shown, the first cylindrical portion 43 has an outer cylindrical surface 43f facing radially outward. The second cylindrical portion 53 has an inner cylindrical surface 53f facing radially inward. The inner cylindrical surface 53f faces the outer cylindrical surface 43f with a first gap S1 between them. The first gap S1 is a cylindrical space (gap) with a small radial dimension formed between the inner cylindrical surface 53f and the outer cylindrical surface 43f.

[0029] The first top surface portion 42 has a first flat surface 42f oriented in the first axial direction C1. The second top surface portion 52 has a second flat surface 52f oriented in the second axial direction C2. The first flat surface 42f and the second flat surface 52f are opposed to each other. A protrusion 60 is provided on the first top surface portion 42 or the second top surface portion 52 to form a second gap S2 between the first flat surface 42f and the second flat surface 52f. The second gap S2 comprises a generally annular space (gap) with a small axial dimension.

[0030] When the protrusion 60 is provided on the first top surface portion 42, it protrudes in the first axial direction C1 beyond the first plane 42f and abuts (contacts) the second plane 52f. On the other hand, when the protrusion 60 is provided on the second top surface portion 52, it protrudes in the second axial direction C2 beyond the second plane 52f and abuts (contacts) the first plane 42f. The protrusion 60 abuts against either the first plane 42f or the second plane 52f, preventing the first and second planes 42f, 52f from abutting each other. A second gap S2 is formed between the first and second planes 42f, with a width (axial dimension) equal to the protrusion of the protrusion 60. Adhesive G is provided in the second gap S2, and the fan unit 3 is bonded and fixed to the rotor 5 using this adhesive G.

[0031] However, in conventional centrifugal fans, such as those disclosed in Patent Document 1, adhesive is interposed between the cylindrical portion of the rotor (the rotor holder in Patent Document 1) and the cylindrical portion of the fan portion (the blade support portion in Patent Document 1) that is fitted externally to the cylindrical portion of the rotor. In contrast to this structure, in the centrifugal fan 1 of the present invention, a first gap S1 is provided between the outer cylindrical surface 43f of the first cylindrical portion 43 and the inner cylindrical surface 53f of the second cylindrical portion 53. Furthermore, a second gap S2 is provided between the first flat surface 42f of the first top surface portion 42 and the second flat surface 52f of the second top surface portion 52. Adhesive G is interposed in this second gap S2, thereby bonding and securing the first flat surface 42f and the second flat surface 52f. With these structures, the centrifugal fan 1 suppresses shifts in the center of gravity of the fan portion 3 caused by thermal deformation of the second portion 50, which has a larger linear expansion coefficient than the first portion 40, as will be described later.

[0032] Here, the second portion 50, which has a larger linear expansion coefficient than the first portion 40, may be thermally deformed to a greater extent than the first portion 40 when exposed to an environment with drastic temperature fluctuations. The inventors of the present invention have discovered that the thermal deformation of the cup-shaped second portion 50 has characteristics such that the second cylindrical portion 53 is deformed in such a manner that the diameter thereof is reduced with the boundary between the second top surface portion 52 and the second cylindrical portion 53 as a base point, and that the second top surface portion 52 is deformed in such a manner that it rises toward the first axial direction C1.

[0033] Furthermore, it was discovered that the latter of these deformation characteristics (i.e., the upward deformation of the second top surface portion 52) is caused by the displacement of the center of gravity of the fan unit 3. Furthermore, the following insight was obtained: in conventional centrifugal fans in which an adhesive is provided between the rotor cylinder and the fan cylinder, even if the fan cylinder were to deform in diameter due to temperature changes, this deformation would be inhibited by the adhesive, and this deformation would instead be caused by upward deformation corresponding to the amount of the inhibition of deformation between the top surface portion and the cylinder of the fan unit (the amount of upward deformation would be greater than in a case where deformation of the cylinder was not inhibited).

[0034] Therefore, in the centrifugal fan 1 of the present invention, a first gap S1 is provided between the first cylindrical portion 43 and the second cylindrical portion 53. Even if the second cylindrical portion 53 is deformed and reduced in diameter, this gap S1 does not obstruct the movement. Furthermore, to create space for this first gap S1, the bonding location is changed, and the first top surface portion 42 and the second top surface portion 52 are bonded and fixed.

[0035] Thus, the diameter reduction deformation of the second cylindrical portion 53 is allowed, and therefore will not be replaced by the floating deformation of the second top surface portion 52, and the situation in which the force of the diameter reduction deformation of the second cylindrical portion 53 is converted into the force of deforming the second top surface portion 52 is suppressed. Therefore, the floating deformation of the second top surface portion 52 is suppressed, and the deviation of the center of gravity position of the fan portion 3 is suppressed. In addition, by providing the protrusion 60, a second gap S2 is formed between the first plane 42f and the second plane 52f. By providing the adhesive G in the second gap S2, a higher bonding strength can be obtained than by abutting the first plane 42f and the second plane 52f and bonding them together. Therefore, the fixing strength of the fan portion 3 relative to the rotor 5 is improved.

[0036] [2. Detailed Structure of Centrifugal Fan]

[0037] Below, refer to Figures 1 to 5 The structure of the centrifugal fan 1 according to this embodiment will be described in detail.

[0038] like Figure 1 As shown, centrifugal fan 1 includes the aforementioned motor unit 2 and fan unit 3. Centrifugal fan 1 is configured by, for example, housing motor unit 2 and fan unit 3 within a housing 10 that forms the outer shell of centrifugal fan 1. Centrifugal fan 1 can be used, for example, as a ventilation fan mounted on a seat in a vehicle.

[0039] As described above, the motor unit 2 includes a shaft 4, a rotor 5, and a stator 6. The motor unit 2 of this embodiment is an outer rotor type motor, and the stator 6 is arranged radially inward of the rotor 5. The shaft 4 extends, for example, from a position closer to the second axial direction C2 than the stator 6 to a position closer to the first axial direction C1 than the fan unit 3. The end portion of the shaft 4 on the second axial direction C2 and the axial middle portion can be rotatably supported by the bearing 11. The bearing 11 is held by a cylindrical bearing holder 12 fixed to the housing 10.

[0040] The stator 6 includes an annular stator core 7 formed by stacking a plurality of identically shaped steel plates. A coil (not shown) wound around the stator core 7 via an insulator can be provided on the stator 6. The stator core 7 is fixed to the housing 10 in a non-rotatable manner by being fitted onto the bearing holder 12, with the stacking direction of the steel plates aligned with the axial direction at its center.

[0041] The rotor 5 includes a magnet 8 and a rotor yoke 9, which are arranged radially opposite to the stator core 7. The magnet 8 is formed, for example, from a long rectangular rubber magnet, joined at both ends to form a ring with an inner diameter larger than the outer diameter of the stator core 7. The magnet 8 is fixed to the rotor yoke 9 and is arranged radially outside the stator core 7, facing each other with a gap therebetween.

[0042] The rotor yoke 9 is a member that secures the magnets 8 against relative rotation with respect to the shaft 4 and prevents leakage of the magnets 8's magnetic flux lines. It is made, for example, of a magnetic steel plate (metal). The rotor yoke 9 has, for example, a bottomed cylindrical (cup-shaped) shape that opens in the second axial direction C2 and covers the stator 6 from the first axial direction C1. The rotor yoke 9 includes a first protrusion 21 that fits over the shaft 4, a cylindrical fixing portion 23 located radially outward of the stator core 7, and a connecting surface portion 22 that connects the first protrusion 21 to the fixing portion 23.

[0043] The first protrusion 21 forms a through hole 21h (see Figure 3 ) is, for example, cylindrical and concentric with the axis C. The rotor yoke 9 is fixed to the shaft 4 so as not to rotate relative to the shaft 4 by inserting the shaft 4 into the through hole 21h and press-fitting the first protrusion 21 to the shaft 4.

[0044] The fixing portion 23 is a portion for fixing the magnet 8 and is provided to surround the stator core 7 from the radially outer side. The fixing portion 23 is, for example, cylindrical and concentric with the axis C and extends in the axial direction. Figure 2 As shown, the inner cylindrical surface 23g has a diameter larger than the outer diameter of the stator core 7. The magnet 8 is fixed to the inner cylindrical surface 23g of the fixing portion 23. The magnet 8 is thereby fixed so as to be non-rotatable relative to the shaft 4.

[0045] The connecting surface portion 22 is a portion covering the magnet 8 and the stator 6 from the first axial direction C1 side. The connecting surface portion 22 may be, for example, Figure 1 and Figure 3As shown, the first protrusion 21 is extended radially outward from the end portion on the second axial direction C2 side and connected to the end portion on the first axial direction C1 side of the fixing portion 23 by a combination of a flat surface portion, a curved surface portion, a stepped surface portion, and a tapered surface portion (part). Here, the connecting surface portion 22 shown as an example includes an inner flat surface portion 24, a stepped surface portion 25, an intermediate flat surface portion 26, an inclined surface portion 27, and an outer flat surface portion 28. These parts 24 to 28 are arranged in this order from the radial inside to the radial outside. The inner flat surface portion 24, the intermediate flat surface portion 26, the inclined surface portion 27, and the outer flat surface portion 28 are shown as follows. Figure 3 As shown, when viewed from the axial direction, they are in the shape of a ring concentric with the axis C. The step portion 25 is in the shape of a cylinder concentric with the axis C and extends in the axial direction.

[0046] like Figure 1 As shown, the inner flat portion 24 is connected to the second axial direction C2 side of the first protrusion 21 and extends radially outward. The step portion 25 is connected to the radially outward side of the inner flat portion 24 and extends radially outward in the second axial direction C2. The intermediate flat portion 26 is connected to the second axial direction C2 side of the step portion 25 and extends radially outward. The inclined portion 27 is connected to the radially outward side of the intermediate flat portion 26 and extends radially outward (at an angle) toward the second axial direction C2. The outer flat portion 28 is connected to the radially outward side of the inclined portion 27 and extends radially outward. The radially outward end of the outer flat portion 28 is connected to the end of the fixing portion 23 on the first axial direction C1 side. The connecting surface portion 22 extends radially outward and toward the second axial direction C2 from the first protrusion 21 as a whole, through these portions 24-28. It should be noted that the term "connected" in this specification refers to connecting two portions, not connecting (adjoining) two separate portions.

[0047] In this embodiment, the rotor yoke 9 is provided as the first portion 40. The first protrusion 21 corresponds to the first hole 41, the connecting surface 22 corresponds to the first top surface 42, and the fixing portion 23 corresponds to the first cylindrical portion 43. In addition, the outer cylindrical surface 23f of the fixing portion 23 facing radially outward (see Figure 2 and Figure 3 ) corresponds to the outer cylindrical surface 43f described above. The surface of the intermediate flat surface portion 26 of the connecting surface portion 22 facing the first axial direction C1 (hereinafter referred to as the "adhesive surface 22f") corresponds to the first flat surface 42f described above.

[0048] The fan section 3 is an impeller that sends the fluid sucked in from the radial inside to the radial outside. Figure 4 As shown, the fan unit 3 includes a plurality of blades 31 standing in the axial direction. The blades 31 are arranged at equal intervals in the circumferential direction around the axis C. The fan unit 3 may be provided with a main plate 32 that supports the ends of the blades 31 on the second axial direction C2 side.

[0049] Fan unit 3 Figure 1 As shown, the fan unit 3 may include a bladed main plate 13 integrally formed with a plurality of blade portions 31 and a main plate portion 32, and a shroud 14. The fan unit 3 is configured, for example, by having the shroud 14 attached and fixed to the bladed main plate 13 on the first axial direction C1 side. The bladed main plate 13 and the shroud 14 are assembled, for example, by separately molding a resin having a larger linear expansion coefficient than that of the rotor yoke 9.

[0050] The shroud 14 is a plate fixed to the ends of the plurality of blades 31 on the first axial direction C1 side and has an annular shape with air passage holes 14h for the suction air duct formed radially inward. The shroud 14 is fixed to the bladed main plate 13 by, for example, ultrasonic welding.

[0051] The bladed main plate 13 includes the blade portion 31 and the main plate portion 32. The main plate portion 32 of this embodiment is provided radially outward of the fixing portion 23 of the rotor yoke 9. For example, the main plate portion 32 Figure 1 、 Figure 4 、 Figure 5 As shown, it is in the shape of a flat plate with uniform axial dimensions (thickness, plate thickness), and is in the shape of a ring concentric with the axis C when viewed from the axial direction.

[0052] In this embodiment, a portion corresponding to the second portion 50 is provided radially inward of the main plate portion 32 of the main plate 13 with blades. Furthermore, in this embodiment, the protrusion 60 is provided on the main plate 13 with blades. The main plate 13 with blades includes a second protrusion 33, a top surface portion 34, and a cylindrical portion 35 as portions corresponding to the second portion 50.

[0053] The second protrusion 33 is a portion corresponding to the second hole 51 of the second portion 50, and forms a through hole 33h (see FIG. Figure 4 and Figure 5 ), for example, in a cylindrical shape concentric with the axis C. The inner diameter of the second protrusion 33 is set, for example, to be equal to or slightly larger than the outer diameter of the shaft 4. It should be noted that the second protrusion 33 may or may not be fixed to the shaft 4.

[0054] The top surface portion 34 is a portion corresponding to the second top surface portion 52 of the second portion 50. Figure 1 As shown, the second protrusion 33 extends radially outward and is connected to the radially inner side of the main plate portion 32 , thereby covering the rotor yoke 9 from the first axial direction C1 side.

[0055] The top surface portion 34 of this embodiment is provided with a main surface portion 36 extending radially outward (at an angle) toward the second axial direction C2, corresponding to the extending direction of the connection surface portion 22 of the rotor yoke 9. The main surface portion 36 is a generally plate-shaped portion that is annular and concentric with the axis C when viewed axially. It extends from the second protrusion 33 to the radially inner side of the main plate portion 32. Alternatively, the main surface portion 36 can be described as extending at an angle relative to the axial direction, forming an arcuate shape that projects toward the first axial direction C1 when viewed radially. This main surface portion 36 facilitates the guidance of fluid drawn in from the first axial direction C1 toward the second axial direction C2 and radially outward along the extending direction of the main surface portion 36.

[0056] It should be noted that if Figure 1 and Figure 4 As shown, the ends of the plurality of blade portions 31 on the second axial direction C2 side may be connected not only to the main plate portion 32 but also to the main surface portion 36. That is, the main surface portion 36 may share the function of the main plate portion 32 (the function of supporting the ends of the plurality of blade portions 31 on the second axial direction C2 side) with the main plate portion 32. The thickness of the plate-shaped main surface portion 36 is preferably the same as that of the main plate portion 32.

[0057] like Figure 2 As shown, the top surface portion 34 may further be provided with a rib 37 that protrudes from the main surface portion 36 in the second axial direction C2 to reinforce the main surface portion 36. Here, the end surface 37f of the rib 37 on the second axial direction C2 side corresponds to the second plane 52f described above. Therefore, the rib 37 is provided so that its end surface 37f is positioned opposite to the bonding surface 22f of the rotor yoke 9. The rib 37 is preferably as follows: Figure 1 and Figure 4 As shown, it is provided at a position separated radially inward from the radially outer end of the main surface portion 36 (ie, the position where the cylindrical portion 35 is provided) and radially outward from the second protrusion 33 .

[0058] On the top surface 34 Figure 5 As shown, an annular rib 38 and an auxiliary rib 39 may be provided as the rib 37. The annular rib 38 is a portion protruding from the main surface portion 36 toward the second axial direction C2 in a cylindrical shape concentric with the axis C, and has an annular shape concentric with the axis C when viewed from the second axial direction C2.

[0059] The auxiliary rib 39 is a portion that projects from the main surface portion 36 toward the second axial direction C2 and extends radially outward from a portion of the annular rib portion 38. For example, it has a rectangular shape when viewed from the second axial direction C2. In this embodiment, as described above, the main surface portion 36 extends radially outward and toward the second axial direction C2. Therefore, the auxiliary rib 39 that projects from the main surface portion 36 has a generally triangular prism shape with the circumferential direction being the height direction.

[0060] It should be noted that there can be multiple auxiliary ribs 39 as shown in the figure. Here, twelve auxiliary ribs 39 are provided. The twelve auxiliary ribs 39 are all of the same shape, separated from each other in the circumferential direction and arranged at equal intervals, and radially extending toward the radial outside of the annular rib 38. It should be noted that in Figure 5 In FIG. 1 , only one auxiliary rib 39 among the twelve auxiliary ribs 39 is denoted by a reference numeral.

[0061] The annular rib 38 and the auxiliary rib 39 are as shown in FIG. Figure 2 and Figure 5 That is, the annular end surface 38f of the annular rib 38 on the second axial direction C2 side and the rectangular end surface 39f of the auxiliary rib 39 on the second axial direction C2 side form a continuous plane (a plane perpendicular to the axial direction) and form the end surface 37f of the rib 37.

[0062] In this embodiment, the convex portion 60 is as follows Figure 2 and Figure 5 As shown, the rib 39 protrudes from the rectangular end surface 39f of the auxiliary rib 39 in the second axial direction C2. The protrusion 60 relative to the rectangular end surface 39f is preferably set to an amount equivalent to the optimal film thickness of the adhesive G. The optimal film thickness herein refers to the film thickness at which the adhesive G exhibits a strength sufficient to withstand the loads expected during use as the centrifugal fan 1. For example, the relationship between film thickness and adhesive strength can be verified through experiments, simulations, etc. for adhesive G that meets the specifications of the centrifugal fan 1, and the optimal film thickness can be determined based on the verification results.

[0063] Here, if Figure 5 As shown, three protrusions 60 of the same shape are separated from each other and arranged at equal intervals along the circumferential direction. The three protrusions 60 are each provided on three of the twelve auxiliary ribs 39. More specifically, the three protrusions 60 are each provided on every other three of the twelve auxiliary ribs 39.

[0064] The three protrusions 60 are designed to protrude the same amount relative to the rectangular end surface 39f. These three protrusions 60 abut (contact) the bonding surface 22f of the rotor yoke 9, aligning the end surface 37f of the rib 37 parallel to the bonding surface 22f. Consequently, the axial width of the second gap S2 formed between the bonding surface 22f and the end surface 37f is uniform, improving the bonding balance of the fan unit 3 to the rotor 5.

[0065] The second gap S2 is formed between the annular end surface 38f and the bonding surface 22f, and between the rectangular end surface 39f and the bonding surface 22f. Therefore, when viewed axially, the second gap S2 comprises a circular annular space (gap) and spaces (gaps) extending radially outward from the circular annular space. The adhesive G is disposed in these spaces. Specifically, the adhesive G is disposed so as to circumferentially surround the circular annular space and also extend radially outward from the circular annular space.

[0066] It should be noted that the radial width of the annular rib 38 and the circumferential width of the auxiliary rib 39 are preferably set to be equal. Furthermore, the radial width of the annular rib 38 and the circumferential width of the auxiliary rib 39 are preferably set to ensure a bonding area sufficient to achieve a bonding strength that meets the specifications of the centrifugal fan 1 , and are preferably set slightly larger than the thickness of the main surface portion 36 and the main plate portion 32 . This prevents deformation of the bladed main plate 13 caused by differences in curing time due to differences in resin volume during molding.

[0067] The barrel portion 35 is equivalent to the second barrel portion 53 of the second portion 50. Figure 1 and Figure 2 As shown in FIG. 1 , the cylindrical portion 35 extends from the radially outer end of the top portion 34 in the second axial direction C2 to a position overlapping with the fixing portion 23 of the rotor yoke 9 when viewed from the radial direction. Figure 5 As shown, the inner cylindrical surface 35f facing radially inward and the outer cylindrical surface facing radially outward are cylindrical in shape with the same diameter in the axial direction and are concentric with the axis C.

[0068] The inner cylindrical surface 35f of the cylindrical portion 35 corresponds to the inner cylindrical surface 53f of the second portion 50. The diameter of the inner cylindrical surface 35f is as follows: Figure 2 As shown, the size is set to form a first gap S1 between the outer cylindrical surface 23f of the fixing portion 23. The first gap S1 is set to a size such that the cylindrical portion 35 does not contact the fixing portion 23 even when the cylindrical portion 35 is deformed by reducing its diameter. This prevents the fixing portion 23 from hindering the reduction in diameter of the cylindrical portion 35, thereby further suppressing deformation of the top surface portion 34.

[0069] In this embodiment, the portion forming the boundary position between the plate-shaped main surface portion 36 and the cylindrical portion 35 having the same diameter in the axial direction is as shown in FIG. Figure 2 As shown, the wall thickness of the fan section 35a can be relatively thick compared to the rest of the main bladed plate 13. It should be noted that the term "thick wall" here refers to the convergence of the various components that make up the fan section 3, resulting in the convergence of the wall (resin) of the fan section 3. This portion will be referred to as the "thick wall portion 35a" below.

[0070] In this embodiment, as described above, the ends of the plurality of blade portions 31 on the second axial direction C2 side are connected to the main surface portion 36, and the radially inner end of the main plate portion 32 is connected to the radially outer end of the main surface portion 36. Figure 4 As shown, the thickness of the thick portion 35 a can be further increased where the root portion of the blade portion 31 in the second axial direction C2 and the root portion of the main plate portion 32 on the radially inner side converge.

[0071] By forming such a thick portion 35a, the thermal deformation characteristics of the top surface portion 34 and the cylindrical portion 35 provided as the second portion 50 of the fan unit 3 are more easily manifested. However, the first gap S1 allows the cylindrical portion 35 to deform in diameter starting from the thick portion 35a, thereby suppressing deformation of the top surface portion 34. It should be noted that in this embodiment, it is also possible to state that the annular rib 38 and the auxiliary rib 39 are provided at a position separated from the cylindrical portion 35, that is, at a position separated from the thick portion 35a.

[0072] [3. Action, effect]

[0073] (1) In the centrifugal fan 1 described above, a first gap S1 is formed between the outer cylindrical surface 43f (outer cylindrical surface 23f) of the first cylindrical portion 43 (fixing portion 23) and the inner cylindrical surface 53f (inner cylindrical surface 35f) of the second cylindrical portion 53 (cylinder portion 35). Thus, even when the centrifugal fan 1 is used in an environment subject to significant temperature fluctuations, the second cylindrical portion 53 is allowed to undergo diameter reduction deformation due to such temperature fluctuations. This prevents the second top surface portion 52 (top surface portion 34) from floating upward due to the obstruction of the diameter reduction deformation of the second cylindrical portion 53. Consequently, the center of gravity of the fan unit 3 is prevented from shifting.

[0074] Furthermore, the bonding position between the first portion 40 provided on the rotor 5 and the second portion 50 provided on the fan unit 3 is changed to the top surface portions 42 and 52, rather than the cylindrical portions 43 and 53. Thus, instead of the second cylindrical portion 53, the second top surface portion 52, which is bonded to the first portion 40 (rotor yoke 9), includes a second flat surface 52f (end surface 37f) that faces the first flat surface 42f (bonding surface 22f), and a protrusion 60 that protrudes in the first axial direction C1 relative to the second flat surface 52f and abuts against the first flat surface 42f. The protrusion 60 forms a second gap S2 between the first flat surface 42f and the second flat surface 52f. Furthermore, the adhesive G provided in this second gap S2 bonds the first flat surface 42f and the second flat surface 52f together, thereby enhancing the bonding strength between the flat surfaces 42f and 52f. Consequently, the centrifugal fan 1 described above effectively suppresses the shift in the center of gravity associated with thermal deformation while maintaining the bonding strength of the fan unit 3 to the rotor 5.

[0075] (2) When the protrusion amount of the convex portion 60 is set to the optimum film thickness of the adhesive G, the first flat surface 42 f and the second flat surface 52 f can be fixed more firmly.

[0076] (3) A main surface portion 36 is provided on the top surface portion 34, which serves as the second top surface portion 52, extending from the second protrusion 33, which serves as the second hole portion 51, toward the radially outer side and the second axial direction C2. The fan portion 3 is thereby able to smoothly push the fluid drawn in from the first axial direction C1 along the main surface portion 36 toward the second axial direction C2 and the radially outer side. Consequently, the air supply efficiency of the fan portion 3 can be improved. Furthermore, the formation of vortices in the fluid radially inside the fan portion 3 can be suppressed, thereby also achieving noise reduction in the fan portion 3.

[0077] (4) A rib 37 is provided on the top surface portion 34 so as to protrude from the main surface portion 36 in the second axial direction C2 to reinforce the main surface portion 36. By utilizing the end surface 37f of the rib 37 as the second flat surface 52f, the portion forming the second flat surface 52f is not rigidly provided on the top surface portion 34, and the top surface portion 34 serving as the second top surface portion 52 can be bonded and fixed to the connecting surface portion 22 serving as the first top surface portion 42. In addition, by adding the rib 37 to the top surface portion 34, the fluidity of the resin during molding becomes better, and the finishing accuracy of the fan portion 3, such as the flatness and parallelism, can be improved.

[0078] (5) If the rib 37 having the end surface 37f bonded to the bonding surface 22f is provided at a position separated from the cylinder 35 in the radial direction, the rib 37 can be used to suppress the diametrical deformation of the cylinder 35 from being hindered. As a result, the force that suppresses the diametrical deformation of the cylinder 35 is replaced by the upward deformation of the top surface 34, thereby effectively suppressing the displacement of the center of gravity of the fan 3. In addition, if the rib 37 is provided at a position separated from the cylinder 35, the resin can be suppressed from gathering around the cylinder 35, thereby suppressing the diametrical deformation of the cylinder 35. The root portion of the main surface 36 side of the cylinder 35 is the point where the axial root portion of the blade portion 31 and the radially inner root portion of the main plate portion 32 meet. If the rib 37 is provided at a position separated from the cylinder 35, the wall thickness of the thick portion 35a is reduced, that is, the diametrical deformation of the cylinder 35, the upward deformation of the top surface 34, and the warping deformation of the main plate portion 32 can be suppressed. This can suppress the displacement of the center of gravity of the fan unit 3 .

[0079] (6) If the rib 37 is provided at a position separated from the second protrusion 33 in the radial direction, the amount of protrusion of the rib 37 relative to the main surface portion 36 extending radially outward and in the second axial direction C2 can be reduced. Consequently, the formability of the bladed main plate 13 as the second portion 50, which includes the second protrusion 33, the top surface portion 34, and the cylindrical portion 35, can be improved. Furthermore, when the annular rib 38 is provided at a position separated from the second protrusion 33, the area of ​​the annular end surface 38f of the annular rib 38 is increased. Consequently, the bonding area is increased, and the bonding strength can be improved.

[0080] (7) In the centrifugal fan 1 described above, the protrusion 60 protrudes from the end surface 37f of the rib 37. This improves the moldability of the main plate 13 with blades. In particular, when the main plate 13 with blades is made of resin, if the rib 37 and the protrusion 60 are provided separately, there is a possibility that the resin is not fully filled in the protrusion 60 during the molding of the main plate 13 with blades. However, by making the protrusion 60 protrude from the end surface 37f of the rib 37, such a problem can be suppressed. In addition, by making the protrusion 60 protrude from the end surface 37f of the rib 37, the error in the amount of protrusion of the protrusion 60 relative to the end surface 37f of the rib 37 can be reduced. Therefore, a space (second gap S2) in which a more appropriate amount (film thickness) of adhesive G is interposed between the end surface 37f and the bonding surface 22f can be ensured.

[0081] (8) In the centrifugal fan 1 described above, an annular rib 38 and an auxiliary rib 39 extending radially outward from the annular rib 38 are provided as the rib 37. The auxiliary rib 39 is provided radially outward, not radially inward, of the annular rib 38, thereby suppressing the amount of protrusion of the auxiliary rib 39 relative to the main surface 36. Furthermore, when the main plate 13 with blades is made of resin, suppressing the amount of protrusion of the auxiliary rib 39 can suppress deformation of the shape caused by differences in curing time due to differences in the amount of resin during molding.

[0082] Furthermore, in the centrifugal fan 1 described above, the protrusion 60 protrudes from the rectangular end surface 39f of the auxiliary rib 39. This allows adhesive G to be applied in an annular shape to the annular space (a portion of the second gap S2) between the annular end surface 38f of the annular rib 38 and the bonding surface 22f. This improves the bonding balance between the fan unit 3 and the rotor 5.

[0083] (9) In the centrifugal fan 1 described above, the three protrusions 60 are separated from each other and arranged at equal intervals in the circumferential direction. This allows the end surface 37f to be flattened relative to the bonding surface 22f (the end surface 37f is arranged parallel to the bonding surface 22f), thereby making the axial width of the second gap S2 uniform. Consequently, uneven bonding of the adhesive G can be suppressed, thereby improving the bonding balance of the fan unit 3 relative to the rotor 5. It should be noted that if three or more protrusions 60 are provided on the auxiliary rib 39 located radially outward of the annular rib 38, the accuracy of flattening the end surface 37f can be further improved.

[0084] (10) In a case where the main plate 13 with blades having the second protrusion 33, the top surface portion 34, and the cylindrical portion 35 as the second part 50 is made of resin, and the rotor yoke 9 as the first part 40 is made of metal, if the protrusion 60 is provided on the side of the main plate 13 with blades, the main plate 13 with blades including the protrusion 60 can be easily molded by a resin having a higher moldability than metal.

[0085] [4. Others]

[0086] The structure of the centrifugal fan 1 described above is an example, and the present invention is not limited to the structure described above.

[0087] For example, the motor unit 2 may be an inner rotor type motor. The first portion 40 provided on the rotor 5 only needs to include at least the first top portion 42 and the first cylindrical portion 43 and is not limited to the rotor yoke 9. Furthermore, the first portion 40 does not need to be cup-shaped. The first portion 40 only needs to be made of a material with a smaller linear expansion coefficient than the second portion 50 and does not need to be made of metal.

[0088] The first top surface portion 42 only needs to have a first flat surface 42f extending radially outward from the first hole portion 41 and toward the first axial direction C1. That is, the first top surface portion 42 may not be a surface extending radially outward and toward the second axial direction C2 like the aforementioned connecting surface portion 22. In addition, the first top surface portion 42 may not have multiple portions 24 to 28 extending in different directions like the aforementioned connecting surface portion 22. The first cylindrical portion 43 may only need to extend from at least the radially outer end portion of the first top surface portion 42 toward the second axial direction C2, and may not surround the stator core 7 from the radially outer side like the aforementioned fixing portion 23.

[0089] The fan portion 3 only needs to have a plurality of blade portions 31. The shroud 14 may be omitted, and the blade portion 31 and the main plate portion 32 may not be formed integrally as the main plate 13 with blades. The second portion 50 provided in the fan portion 3 only needs to be a portion having at least the second top portion 52 and the second cylindrical portion 53, and may also be a portion (component) provided separately from the main plate 13 with blades. The second portion 50 may be made of at least a material having a larger linear expansion coefficient than that of the first portion 40, and may not be a resin product. The first portion 40 and the second portion 50 may both be made of resin or metal products if they satisfy the relationship between the linear expansion coefficients.

[0090] The second top surface portion 52 may be a portion that extends radially outward from at least the second hole portion 51 and has a second flat surface 52f that opposes the first flat surface 42f. Alternatively, the second top surface portion 52 may be a portion that does not include the aforementioned main surface portion 36 or rib portion 37 and simply extends perpendicularly to the axial direction from the second hole portion 51 to form the second flat surface 52f that opposes the first flat surface 42f. The configuration of the rib portion 37 is merely an example; for example, either the annular rib portion 38 or the auxiliary rib portion 39 may be omitted.

[0091] The first cylindrical portion 43 may be at least cylindrical and have an outer cylindrical surface 43f facing radially outward, and the second cylindrical portion 53 may be at least cylindrical and have an inner cylindrical surface 53f facing the outer cylindrical surface 43f with a first gap S1 therebetween. The first cylindrical portion 43 and the second cylindrical portion 53 may not be cylindrical, and may be, for example, cylindrical with a polygonal outer shape when viewed from the axial direction.

[0092] In the centrifugal fan 1 described above, the protrusion 60 protrudes from the rectangular end surface 39f of the auxiliary rib 39 in the second axial direction C2. However, the protrusion 60 may also protrude from the annular end surface 38f of the annular rib 38. Furthermore, the protrusion 60 does not need to protrude from the end surface 37f. For example, the protrusion 60 may protrude from the main surface portion 36 in the second axial direction C2 rather than from the rib 37. The protrusion 60 may also be provided on the first top surface portion 42 of the rotor 5.

[0093] [Description of Reference Numerals]

[0094] 1 centrifugal fan

[0095] 3 Fan unit

[0096] 4-axis

[0097] 5 rotor

[0098] 21 First protrusion (first hole)

[0099] 22 Connecting face (first top face)

[0100] 22f bonding surface (first plane)

[0101] 23. Fixing portion (first cylinder)

[0102] 23f outer cylinder surface

[0103] 31 blade

[0104] 33 Second protrusion (second hole)

[0105] 34 Top face (second top face)

[0106] 35 Cylinder (Second Cylinder)

[0107] 35f inner cylinder surface

[0108] 36 Main face

[0109] 37 ribs

[0110] 37f end face (second plane)

[0111] 38 annular ribs

[0112] 38f annular end surface (second plane)

[0113] 39 Auxiliary ribs

[0114] 39f rectangular end face (second plane)

[0115] 40 Part 1

[0116] 41 First hole

[0117] 42 First Facial

[0118] 42f First plane

[0119] 43 First tube

[0120] 43f outer cylinder surface

[0121] 50 Part 2

[0122] 51 Second hole

[0123] 52 Second facial

[0124] 52f Second Plane

[0125] 53 Second tube

[0126] 53f inner cylinder surface

[0127] 60 bulge

[0128] C1 First Axis

[0129] C2 Second Axis

[0130] G Adhesive

[0131] S1 First gap

[0132] S2 Second gap.

Claims

1. A centrifugal fan, characterized in that: The centrifugal fan has: A first portion is provided on a rotor that rotates integrally with the shaft; and The second portion is provided in a fan portion having a plurality of blades and fixed to the rotor, and has a larger linear expansion coefficient than the first portion. The first part has: a first top surface portion extending from a first hole portion through which the shaft passes toward a radially outer side of the shaft and having a first flat surface facing a first axial direction of the shaft; and a cylindrical first cylindrical portion extending from the radially outer end portion of the first top surface portion in a second axial direction opposite to the first axial direction, The second part has: a second top surface portion located closer to the first axial direction than the first top surface portion, extending from a second hole portion through which the shaft passes toward the radially outer side, and having a second flat surface opposed to the first flat surface; and a cylindrical second cylindrical portion extending from the radially outer end of the second top surface portion toward the second axial direction and having an inner cylindrical surface opposed to the outer cylindrical surface of the first cylindrical portion with a first gap therebetween; The first top surface portion is provided with a convex portion that protrudes from the first plane toward the first axial direction and abuts against the second plane, or the second top surface portion is provided with a convex portion that protrudes from the second plane toward the second axial direction and abuts against the first plane. The first flat surface and the second flat surface are bonded and fixed by an adhesive provided in a second gap formed by the protrusion.

2. The centrifugal fan according to claim 1, wherein: The amount of protrusion of the convex portion relative to the first plane or the second plane is set to an optimum film thickness of the adhesive.

3. The centrifugal fan according to claim 1, wherein: The second top surface portion has a main surface portion extending from the second hole portion toward the radially outer side and the second axial direction side.

4. The centrifugal fan according to claim 3, wherein: The second top surface portion further includes a rib portion protruding from the main surface portion toward the second axial direction to reinforce the main surface portion. The end surface of the rib on the second axial side forms the second plane.

5. The centrifugal fan according to claim 4, wherein: The convex portion protrudes from the second plane of the second top surface portion.

6. The centrifugal fan according to claim 5, characterized in that: The rib portion includes an annular rib portion that projects from the main surface portion toward the second axial direction and is annular when viewed from the second axial direction side, and an auxiliary rib portion that projects from the main surface portion toward the second axial direction and extends radially outward from the annular rib portion. The projection protrudes from the end surface of the auxiliary rib on the second axial side.

7. The centrifugal fan according to any one of claims 4 to 6, characterized in that: The rib portion is provided at a position spaced apart from the second cylindrical portion in the radial direction.

8. The centrifugal fan according to claim 7, wherein: The rib portion is provided at a position spaced apart from the second hole portion in the radial direction.

9. The centrifugal fan according to claim 1, wherein: The first part is a metal product, The second part is a resin product, The convex portion is provided on the second top surface portion.

10. The centrifugal fan according to claim 1, wherein: At least three protrusions are provided on the first top surface portion or the second top surface portion, At least three of the protrusions are separated from each other and arranged at equal intervals in the circumferential direction of the shaft.

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