Centrifugal fan

Abstract

The centrifugal fan (1) includes a first portion (40) provided on the rotor (5) and a second portion (50) provided on the fan portion (3) and having a linear expansion coefficient larger than that of the first portion (40). The first portion (40) has a first end face portion (42) and a first cylindrical portion (43). The second portion (50) has a second end face portion (52) and a second cylindrical portion (53). The second cylindrical portion (53) has an inner cylindrical surface (53f) facing the outer cylindrical surface (43f) of the first cylindrical portion (43) with a first clearance (S1). The first end face portion (42) has a first plane (42f), and the second end face portion (52) has a second plane (52f) facing the first plane (42f). A convex portion (60) is provided on the first end face portion (42) or the second end face portion (52). The first plane (42f) and the second plane (52f) are adhesively fixed by an adhesive (G) provided in a second clearance (S2) formed by the convex portion (60).

Description

Technical Field

[0001] This invention relates to a centrifugal fan.

Background Art

[0002] A centrifugal fan includes a fan unit having a plurality of blades and a motor unit serving as a drive source for the fan unit. As the fan unit rotates, it sends out the fluid inhaled from the vicinity of the rotation center to the outside in the radial direction of the fan unit. Conventionally, there is known a centrifugal fan in which the fan unit is fixed to the rotor of the motor unit so that the rotor and the fan unit rotate integrally. For example, Patent Document 1 discloses a centrifugal fan in which the outer peripheral surface of a metal rotor holder (rotor) provided on a motor (motor unit) and the inner peripheral surface of the blade support portion of a resin impeller (fan unit) are fixed with an adhesive.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when the outer peripheral surface of the rotor holder and the inner peripheral surface of the blade support portion of the fan unit are adhesively fixed as in Patent Document 1, depending on the usage environment of the centrifugal fan, a shift in the center of gravity due to thermal deformation may occur. Here, the thermal deformation refers to the dimensional changes of the fan unit and the fixing member (the rotor holder in Patent Document 1) to which the fan unit is fixed, respectively, along with the temperature and temperature changes around the centrifugal fan. The fan unit and the fixing member are often formed of different materials. For example, as in Patent Document 1, the fan unit may be made of resin and the fixing member may be made of metal. In this way, when the fan unit is formed of a material with a larger coefficient of linear expansion than the fixing member, the amount of thermal deformation of the fan unit becomes larger than that of the fixing member. Therefore, the center of gravity position of the fan unit relative to the fixing member may shift from the position before thermal deformation (initially). If a shift occurs in the center of gravity position of the fan unit, it may have an adverse effect on the fan balance, and vibration and noise may occur during the operation of the centrifugal fan.

[0005] The centrifugal fan of the present case was devised in view of such problems, and one of its purposes is to suppress the shift in the center of gravity accompanying thermal deformation. Note that, not limited to this purpose, another purpose of the present case is also to exhibit an operational effect that cannot be obtained by the conventional technology, which is an operational effect derived from each configuration shown in the form for carrying out the invention described later.

Means for Solving the Problems

[0006] The disclosed centrifugal fan can be realized as the following disclosed modes (application examples) and solves at least a part of the above problems.

[0007] The centrifugal fan disclosed includes a first part provided on a rotor that rotates integrally with a shaft, and a second part provided on a fan part having a plurality of blade parts and fixed to the rotor, the second part having a linear expansion coefficient larger than that of the first part. The first part extends radially outward from a first hole through which the shaft is inserted, and has a first end face having a first plane facing a first axial direction among the axial directions of the shaft, and a cylindrical first cylinder part extending in a second axial direction opposite to the first axial direction from an end portion on the radially outer side of the first end face. The second part is located in the first axial direction relative to the first end face, extends radially outward from a second hole through which the shaft is inserted, and has a second end face having a second plane facing the first plane, and a cylindrical second cylinder part extending in the second axial direction from an end portion on the radially outer side of the second end face and having an inner cylinder face facing the outer cylinder face of the first cylinder part with a first clearance therebetween. A convex part that protrudes in the first axial direction from the first plane and abuts against the second plane is provided on the first end face, or a convex part that protrudes in the second axial direction from the second plane and abuts against the first plane is provided on the second end face. The first plane and the second plane are adhesively fixed by an adhesive provided in a second clearance formed by the convex part.

Effect of the Invention

[0008] According to the centrifugal fan disclosed, displacement of the center of gravity due to thermal deformation can be suppressed.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0010] With reference to the drawings, the centrifugal fan as an embodiment will be described. The following embodiments are merely examples, and there is no intention to exclude various modifications and applications of technologies not explicitly shown in the following embodiments. Each configuration of the present embodiment can be implemented with various modifications without departing from their gist.

[0011] [1. Overview] Hereinafter, with reference to FIGS. 1 and 2, after explaining the overview of the centrifugal fan 1 of the present embodiment, the configuration of the centrifugal fan 1 will be described in detail. FIG. 1 is an axial cross-sectional view of the centrifugal fan 1 of the present embodiment, and FIG. 2 is an enlarged view of the X part of FIG. 1.

[0012] As shown in FIG. 1, the centrifugal fan 1 includes a motor unit 2 as a drive source and a fan unit 3 driven by the motor unit 2. The motor unit 2 has a shaft 4, a rotor 5 that rotates integrally with the shaft 4, and a stator 6 disposed opposite to the rotor 5. The fan unit 3 is an impeller that rotates coaxially with the shaft 4 to send out the fluid inhaled from the rotation center side to the outside (the direction away from the rotation center), and has a plurality of blade parts 31. The fan unit 3 is attached to one side (the first axial direction C1 side described later) in the axial direction of the shaft 4 with respect to the rotor 5 of the motor unit 2 and is fixed to the rotor 5, so as to rotate integrally with the shaft 4 and the rotor 5.

[0013] Hereinafter, the extending direction of the shaft 4 (the direction of the axis C of the shaft 4) is referred to as the axial direction. Among the axial directions, the direction in which the fan unit 3 is attached to the rotor 5 of the motor unit 2 is referred to as the first axial direction C1, and the direction opposite to the first axial direction C1 is referred to as the second axial direction C2. Also, the direction orthogonal to the axial direction and away from the axis C of the shaft 4 is referred to as the radially outer side, and the same direction and the direction toward the axis C is referred to as the radially inner side. When not distinguishing between the inside and the outside, it is simply referred to as the radial direction. The direction orthogonal to the axial direction and circulating around the axis C is referred to as the circumferential direction.

[0014] On the rotor 5, a first portion 40 is provided on the first axial direction C1 side of the rotor 5. On the fan portion 3 attached to the rotor 5 in the first axial direction C1, a cup-shaped second portion 50 that opens toward the second axial direction C2 is provided on the second axial direction C2 side of the fan portion 3. The second portion 50 is made of a material having a larger linear expansion coefficient than that of the first portion 40.

[0015] In this embodiment, as an example, the rotor yoke 9 of the rotor 5 described later corresponds to the first portion 40. Also, a configuration will be described in which a radially inner portion of the main plate portion 32 (both described later) of the main plate 13 with blades of the fan portion 3 corresponds to the second portion 50. However, the first portion 40 does not have to be the rotor yoke 9, and the second portion 50 does not have to be a part of the main plate 13 with blades. In each figure, in order to make it easy to understand the correspondence between the parts and surfaces (each element) of the first portion 40 and the second portion 50 and each specific example configuration, the reference numeral "40" indicating the first portion is shown in parentheses, and the reference numerals indicating the elements of the first portion 40 and the second portion 50 are shown in parentheses.

[0016] The first portion 40 has a first end face portion 42 extending radially outward from a first hole portion 41 through which the shaft 4 is inserted, and a cylindrical first cylinder portion 43 extending in the second axial direction C2 from an end portion on the radially outer side of the first end face portion 42. The first hole portion 41 is a portion that forms a through hole through which the shaft 4 is inserted around the shaft 4. Here, the term "extending toward" is not limited to extending in a direction (for example, the radial direction) that coincides with (is parallel to) the reference direction, but also includes extending in a direction inclined with respect to the reference direction. The same shall apply when the following description refers to "extending toward".

[0017] The second part 50 has a second end face portion 52 that extends radially outward from a second hole portion 51 through which the shaft 4 is inserted, and a cylindrical second cylinder portion 53 that extends in a second axial direction C2 from the radially outer end of the second end face portion 52 (the boundary position between the second end face portion 52 and a main board portion 32 described later). The second hole portion 51 is a portion that forms a through hole through which the shaft 4 is inserted around the shaft 4. The second end face portion 52 is provided on the first axial direction C1 side with respect to the first end face portion 42. The second cylinder portion 53 is provided on the outer side in the radial direction with respect to the first cylinder portion 43 and is provided at the same position as the first cylinder portion 43 in the axial direction (a position overlapping the first cylinder portion 43 when viewed from the radial direction). That is, the second part 50 is provided so as to cover the first part 40 from the outer side in the radial direction and the first axial direction C1 side.

[0018] As shown in FIG. 2, the first cylinder portion 43 has an outer cylinder surface 43f facing the outer side in the radial direction. The second cylinder portion 53 has an inner cylinder surface 53f facing the inner side in the radial direction. The inner cylinder surface 53f faces the outer cylinder surface 43f with a first clearance S1 provided therebetween. The first clearance S1 is a cylindrical space (gap) with a small radial dimension formed between the inner cylinder surface 53f and the outer cylinder surface 43f.

[0019] The first end face portion 42 has a first plane 42f facing the first axial direction C1. The second end face portion 52 has a second plane 52f facing the second axial direction C2. The first plane 42f and the second plane 52f are planes facing each other. A convex portion 60 for forming a second clearance S2 is provided on the first end face portion 42 or the second end face portion 52 between the first plane 42f and the second plane 52f. The second clearance S2 includes a substantially annular space (gap) with a small axial dimension.

[0020] When the convex portion 60 is provided on the first end face portion 42, it protrudes in the first axial direction C1 from the first plane 42f and abuts (contacts) against the second plane 52f. On the other hand, when the convex portion 60 is provided on the second end face portion 52, the convex portion 60 protrudes in the second axial direction C2 from the second plane 52f and abuts (contacts) against the first plane 42f. By the convex portion 60 abutting against the first plane 42f or the second plane 52f, the first plane 42f and the second plane 52f do not contact each other, and a second clearance S2 having a width (axial dimension) corresponding to the protruding amount of the convex portion 60 is formed between the first plane 42f and the second plane 52f. An adhesive G is provided in the second clearance S2, and the fan portion 3 is adhesively fixed to the rotor 5 by the adhesive G.

[0021] Incidentally, in a conventional centrifugal fan as disclosed in Patent Document 1, for example, an adhesive is interposed between a cylindrical portion of a rotor (rotor holder in Patent Document 1) and a cylindrical portion of a fan portion (blade support portion in Patent Document 1) externally fitted thereto. In contrast to such a configuration, in the centrifugal fan 1 of the present case, a first clearance 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. Further, a second clearance S2 is also provided between the first plane 42f of the first end face portion 42 and the second plane 52f of the second end face portion 52. By interposing the adhesive G in this second clearance S2, the first plane 42f and the second plane 52f are adhesively fixed. With these configurations, as will be described later, the centrifugal fan 1 suppresses the displacement of the center of gravity position of the fan portion 3 due to the thermal deformation of the second portion 50 having a linear expansion coefficient larger than that of the first portion 40.

[0022] Here, the second portion 50 having a linear expansion coefficient larger than that of the first portion 40 can be thermally deformed more greatly than the first portion 40 when exposed to an environment where the temperature change around it is intense. The inventors of the present case have found that the thermal deformation of the cup-shaped second portion 50 has a tendency to deform such that the second cylindrical portion 53 contracts in diameter with the boundary position between the second end face portion 52 and the second cylindrical portion 53 as a base point, and a tendency to deform such that the second end face portion 52 floats upward on the first axial direction C1 side.

[0023] Also, among these deformation tendencies, it has been found that the latter tendency (i.e., the upward deformation of the second top surface portion 52) is caused by the shift of the center of gravity position of the fan portion 3. Further, in a centrifugal fan in which an adhesive is provided between the cylindrical portion of the rotor and the cylindrical portion of the fan portion as in the prior art, even if the cylindrical portion of the fan portion tries to contract in diameter due to a temperature change, the deformation is inhibited by the adhesive, and to the extent that the deformation of the cylindrical portion is inhibited, it can be replaced by the upward deformation of the top surface portion of the fan portion (the amount of upward deformation increases compared to the case where the deformation of the cylindrical portion is not inhibited).

[0024] Therefore, in the centrifugal fan 1 of the present case, a first clearance S1 is provided between the first cylindrical portion 43 and the second cylindrical portion 53 so as not to inhibit the second cylindrical portion 53 from contracting in diameter. Further, in order to leave this first clearance S1 as a space, the bonding location is changed, and the first top surface portion 42 and the second top surface portion 52 are bonded and fixed.

[0025] As a result, since the contraction in diameter of the second cylindrical portion 53 is allowed, it is not replaced by the upward deformation of the second top surface portion 52, and the force that causes the second cylindrical portion 53 to contract in diameter is suppressed from being converted into the force that deforms the second top surface portion 52. Therefore, the upward deformation of the second top surface portion 52 is suppressed, and the shift of the center of gravity position of the fan portion 3 is suppressed. Further, by providing the convex portion 60, a second clearance S2 is formed between the first plane 42f and the second plane 52f. By providing the adhesive G in the second clearance S2, a higher adhesive strength can be obtained than when the first plane 42f and the second plane 52f are brought into contact and bonded and fixed. Therefore, the fixing strength of the fan portion 3 to the rotor 5 is improved.

[0026] [2. Detailed Configuration of Centrifugal Fan] Hereinafter, with reference to FIGS. 1 to 5, the configuration of the centrifugal fan 1 of the present embodiment will be described in detail. As shown in FIG. 1, the centrifugal fan 1 includes the motor unit 2 and the fan unit 3 described above. The centrifugal fan 1 is configured such that, for example, the motor unit 2 and the fan unit 3 are built into a housing 10 that forms the outer shell of the centrifugal fan 1. The centrifugal fan 1 may be used, for example, as a ventilation fan attached to a vehicle seat.

[0027] As described above, the motor unit 2 has a shaft 4, a rotor 5, and a stator 6. The motor unit 2 of the present embodiment is an outer rotor type motor, and the stator 6 is disposed radially inside the rotor 5. The shaft 4 extends, for example, from the second axial direction C2 side of the stator 6 to the first axial direction C1 side of the fan unit 3. The end portion and the axial intermediate portion of the shaft 4 on the second axial direction C2 side may be rotatably supported by a bearing 11. The bearing 11 is held by a cylindrical bearing holder 12 fixed to the housing 10.

[0028] The stator 6 includes an annular stator core 7 formed by laminating a plurality of steel plates having the same shape. The stator 6 may be provided with a coil (not shown) wound around the stator core 7 via an insulator. The stator core 7 is externally fitted and fixed to the bearing holder 12 with the stacking direction of the steel plates aligned with the axial direction at its center, thereby being fixedly non-rotatable with respect to the housing 10.

[0029] The rotor 5 includes a magnet 8 and a rotor yoke 9 that are disposed to face each other radially with respect to the stator core 7. The magnet 8 is made of, for example, a long rectangular rubber magnet, and is formed by joining both ends of the rubber magnet so as to form an annular shape having 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 disposed to face the outer side in the radial direction of the stator core 7 with a gap therebetween.

[0030] The rotor yoke 9 is a member that fixes the magnet 8 in a non-rotatable manner relative to the shaft 4 and suppresses the leakage of magnetic flux of the magnet 8, and is composed of, for example, a magnetic steel plate (metal). The rotor yoke 9 has, for example, a bottomed cylindrical shape (cup shape) that opens in the second axial direction C2, and covers the stator 6 from the first axial direction C1 side. The rotor yoke 9 is provided with a first boss portion 21 that fits over the shaft 4, a cylindrical fixing portion 23 that is located on the radially outer side of the stator core 7, and a connecting surface portion 22 that connects the first boss portion 21 and the fixing portion 23.

[0031] The first boss portion 21 is a portion that forms a through hole 21h (see FIG. 3) through which the shaft 4 is inserted, and has, for example, a cylindrical shape concentric with the axis C. The rotor yoke 9 is fixed in a non-rotatable manner relative to the shaft 4 by inserting the shaft 4 into the through hole 21h and press-fitting and fixing the first boss portion 21 to the shaft 4.

[0032] The fixing portion 23 is a portion for fixing the magnet 8, and is provided so as to surround the stator core 7 from the radially outer side. The fixing portion 23 has, for example, a cylindrical shape concentric with the axis C and extends in the axial direction. As shown in FIG. 2, the fixing portion 23 has an inner cylindrical surface 23g with 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 in a non-rotatable manner relative to the shaft 4.

[0033] The connection surface portion 22 is a portion that covers the magnet 8 and the stator 6 from the first axis direction C1 side. The connection surface portion 22 may be configured by combining, for example, a flat surface portion, a curved surface portion, a stepped or tapered surface portion (site) that extends radially outward from the end portion on the second axis direction C2 side of the first boss portion 21 and is connected to the end portion on the first axis direction C1 side of the fixing portion 23, as shown in FIGS. 1 and 3. The connection surface portion 22 exemplified here includes an inner flat surface portion 24, a stepped portion 25, an intermediate flat surface portion 26, an inclined surface portion 27, and an outer flat surface portion 28, and these portions 24 to 28 are connected in this order from the radially inner side to the radially outer side. 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 all in an annular shape concentric with the axis C when viewed from the axial direction, as shown in FIG. 3. The stepped portion 25 is in a cylindrical shape concentric with the axis C and extends in the axial direction.

[0034] As shown in FIG. 1, the inner flat surface portion 24 is connected to the second axis direction C2 side of the first boss portion 21 and extends radially outward. The stepped portion 25 is connected to the radially outer side of the inner flat surface portion 24 and extends in the second axis direction C2. The intermediate flat surface portion 26 is connected to the second axis direction C2 side of the stepped portion 25 and extends radially outward. The inclined surface portion 27 is connected to the radially outer side of the intermediate flat surface portion 26 and extends (obliquely) radially outward and in the second axis direction C2 side. The outer flat surface portion 28 is connected to the radially outer side of the inclined surface portion 27 and extends radially outward. The end portion on the first axis direction C1 side of the fixing portion 23 is connected to the radially outer end portion of the outer flat surface portion 28. The connection surface portion 22 extends as a whole radially outward and in the second axis direction C2 side from the first boss portion 21 by these portions 24 to 28. Note that the "connection" referred to in this specification means that two portions are connected, and does not mean connecting (attaching) two separately provided portions.

[0035] In this embodiment, the rotor yoke 9 is provided as the above-described first portion 40. The first boss portion 21 corresponds to the above-described first hole portion 41, the connection surface portion 22 corresponds to the above-described first end surface portion 42, and the fixing portion 23 corresponds to the above-described first cylindrical portion 43. Further, an outer cylindrical surface 23f (see FIGS. 2 and 3) facing the radially outer side of the fixing portion 23 corresponds to the above-described outer cylindrical surface 43f. A surface (hereinafter referred to as "adhesive surface 22f") of the intermediate plane portion 26 of the connection surface portion 22 facing the first axial direction C1 corresponds to the above-described first plane 42f.

[0036] The fan unit 3 is an impeller that discharges the fluid sucked from the radially inner side to the radially outer side, and includes a plurality of blade portions 31 erected in the axial direction as shown in FIG. 4. The plurality of blade portions 31 are arranged at equal intervals in the circumferential direction around the axis C. The fan unit 3 may be provided with a main board portion 32 that supports the ends of the plurality of blade portions 31 on the second axial direction C2 side.

[0037] As shown in FIG. 1, the fan unit 3 may include a main board 13 with blades in which a plurality of blade portions 31 and the main board portion 32 are integrally formed, and a shroud 14. The fan unit 3 is configured, for example, by attaching and fixing the shroud 14 to the main board 13 with blades on the first axial direction C1 side. The main board 13 with blades and the shroud 14 are separately molded, for example, from a resin having a larger linear expansion coefficient than the rotor yoke 9, and then combined.

[0038] The shroud 14 is a plate material fixed to the ends of the plurality of blade portions 31 on the first axial direction C1 side, and has an annular shape in which air passage holes 14h for the suction air guide passage are formed on the radially inner side. The shroud 14 is fixed to the main board 13 with blades, for example, by ultrasonic welding.

[0039] The main board 13 with blades includes the above-described blade portions 31 and the main board portion 32. The main board portion 32 of this embodiment is provided on the radially outer side of the fixing portion 23 of the rotor yoke 9. The main board portion 32 has, for example, a flat plate shape with a uniform axial dimension (thickness, plate thickness) and an annular shape concentric with the axis C when viewed from the axial direction.

[0040] In this embodiment, a portion corresponding to the second portion 50 described above is provided inside the main plate portion 32 of the main plate 13 with blades in the radial direction. Further, in this embodiment, the convex portion 60 described above is provided on the main plate 13 with blades. On the main plate 13 with blades, a second boss portion 33, a top surface portion 34, and a cylindrical portion 35 are provided as portions corresponding to the second portion 50.

[0041] The second boss portion 33 is a portion corresponding to the second hole portion 51 of the second portion 50 described above, and is a portion forming a through hole 33h (see FIGS. 4 and 5) through which the shaft 4 is inserted, and for example, has a cylindrical shape concentric with the axis C. The inner diameter of the second boss portion 33 is set to be, for example, equal to the outer diameter of the shaft 4 or slightly larger than the outer diameter of the shaft 4. Note that the second boss portion 33 may or may not be fixed to the shaft 4.

[0042] The top surface portion 34 is a portion corresponding to the second top surface portion 52 of the second portion 50 described above. As shown in FIG. 1, the top surface portion 34 extends radially outward from the second boss portion 33 and is connected to the inner side in the radial direction of the main plate portion 32, thereby covering the rotor yoke 9 from the first axial direction C1 side.

[0043] On the top surface portion 34 of this embodiment, a main surface portion 36 extending (obliquely) radially outward and toward the second axial direction C2 side is provided corresponding to the extending direction of the connection surface portion 22 of the rotor yoke 9 described above. The main surface portion 36 is a substantially plate-shaped portion having an annular shape concentric with the axis C when viewed from the axial direction, and extends from the second boss portion 33 to the inner side in the radial direction of the main plate portion 32. It can also be said that the main surface portion 36 extends obliquely with respect to the axial direction so as to form a mountain shape protruding toward the first axial direction C1 side when viewed from the radial direction. Due to such a main surface portion 36, the fluid sucked from the first axial direction C1 side is easily guided along the extending direction of the main surface portion 36 to the second axial direction C2 side and radially outward.

[0044] As shown in FIGS. 1 and 4, the ends of the plurality of blade portions 31 on the second axis 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, together with the main plate portion 32, perform the function of the main plate portion 32 (the function of supporting the ends of the plurality of blade portions 31 on the second axis direction C2 side). The thickness of the plate-shaped main surface portion 36 is preferably made equal to the thickness of the main plate portion 32.

[0045] As shown in FIG. 2, the top surface portion 34 may further be provided with a rib portion 37 that projects from the main surface portion 36 in the second axis direction C2 to reinforce the main surface portion 36. Here, the end surface 37f of the rib portion 37 on the second axis direction C2 side corresponds to the above-described second plane 52f. For this reason, the rib portion 37 is provided at a position where its end surface 37f faces the adhesion surface 22f of the rotor yoke 9. The rib portion 37 is preferably provided at a position radially inwardly spaced from the radially outer end of the main surface portion 36 (i.e., the position where the cylindrical portion 35 is provided) as shown in FIGS. 1 and 4, and is radially outwardly spaced from the second boss portion 33.

[0046] As shown in FIG. 5, an annular rib portion 38 and an auxiliary rib portion 39 may be provided as the rib portion 37 on the top surface portion 34. The annular rib portion 38 is a portion that projects from the main surface portion 36 in the second axis direction C2 so as to form a cylindrical shape concentric with the axis C, and forms an annular shape concentric with the axis C when viewed from the second axis direction C2 side.

[0047] The auxiliary rib portion 39 is a portion that projects from the main surface portion 36 in the second axis direction C2 and extends radially outward from a part of the annular rib portion 38, and forms, for example, a rectangular shape when viewed from the second axis direction C2 side. In the present embodiment, as described above, since the main surface portion 36 extends radially outward and toward the second axis direction C2 side, the auxiliary rib portion 39 projecting from the main surface portion 36 forms a substantially triangular prism shape with the circumferential direction as the height direction.

[0048] Note that, as shown in the figure, a plurality of auxiliary rib portions 39 may be provided. Here, twelve auxiliary rib portions 39 are provided. The twelve auxiliary rib portions 39 all have the same shape, are spaced apart from each other at equal intervals in the circumferential direction, and extend radially outward from the radially outer side of the annular rib portion 38. In FIG. 5, only one of the twelve auxiliary rib portions 39 is labeled.

[0049] As shown in FIGS. 2 and 5, both the annular rib portion 38 and the auxiliary rib portion 39 project to the same position in the axial direction. That is, the annular end face 38f on the second axial direction C2 side of the annular rib portion 38 and the rectangular end face 39f on the second axial direction C2 side of the auxiliary rib portion 39 form a single continuous plane (a plane perpendicular to the axial direction), forming the end face 37f of the rib portion 37.

[0050] In the present embodiment, as shown in FIGS. 2 and 5, the convex portion 60 projects from the rectangular end face 39f of the auxiliary rib portion 39 in the second axial direction C2. The protruding amount of the convex portion 60 with respect to the rectangular end face 39f is preferably set to be equivalent to the optimum film thickness of the adhesive G. The optimum film thickness here means the film thickness when the adhesive strength by the adhesive G exhibits a strength capable of withstanding the load assumed when used as the centrifugal fan 1. The optimum film thickness may be determined, for example, based on the verification results of the relationship between the film thickness and the adhesive strength through experiments, simulations, etc. for the adhesive G that satisfies the specifications of the centrifugal fan 1.

[0051] Here, as shown in FIG. 5, three convex portions 60 having the same shape are provided at equal intervals in the circumferential direction, spaced apart from each other. Each of the three convex portions 60 is provided on each of three of the twelve auxiliary rib portions 39. More specifically, each of the three convex portions 60 is provided on each of the three auxiliary rib portions 39 provided at every third one among the twelve auxiliary rib portions 39.

[0052] The three convex portions 60 are set such that the protruding amounts with respect to the rectangular end face 39f are the same. When these three convex portions 60 abut (contact) against the adhesion surface 22f of the rotor yoke 9, the end face 37f of the rib portion 37 is arranged parallel to the adhesion surface 22f. Therefore, the axial width of the second clearance S2 formed between the adhesion surface 22f and the end face 37f becomes uniform, and the adhesion balance of the fan portion 3 with respect to the rotor 5 is improved.

[0053] The second clearance S2 is formed between the annular end face 38f and the rectangular end face 39f and the adhesion surface 22f. For this reason, the second clearance S2 includes, when viewed from the axial direction, an annular space (gap) and a space (gap) radially extending outward from the annular space in the radial direction. The adhesive G is provided in these spaces. That is, the adhesive G is provided so as to go around the circumferential direction in the above-described annular space and is also provided so as to extend radially outward from the annular space.

[0054] Note that the radial width of the annular rib portion 38 and the circumferential width of the auxiliary rib portion 39 are preferably set to be equal. The radial width of the annular rib portion 38 and the circumferential width of the auxiliary rib portion 39 are more preferably widths that can secure an adhesion area capable of obtaining an adhesion strength that satisfies the specifications of the centrifugal fan 1, and are preferably set to be slightly larger than the thicknesses of the main surface portion 36 and the main board portion 32. Thereby, when molding the main board 13 with blades, shape distortion caused by a difference in curing time due to a difference in the amount of resin is suppressed.

[0055] The cylindrical portion 35 is a portion corresponding to the second cylindrical portion 53 of the second portion 50 described above. As shown in FIGS. 1 and 2, the cylindrical portion 35 extends in the second axial direction C2 from the radially outer end of the top surface portion 34 to a position overlapping the fixing portion 23 of the rotor yoke 9 when viewed in the radial direction. The cylindrical portion 35 has, for example, a cylindrical shape in which the inner cylindrical surface 35f facing the radially inner side and the outer cylindrical surface facing the radially outer side each have a uniform diameter in the axial direction and is concentric with the axis C.

[0056] The inner cylindrical surface 35f of the cylindrical portion 35 corresponds to the inner cylindrical surface 53f of the second portion 50 described above. As shown in FIG. 2, the diameter of the inner cylindrical surface 35f is set to a size that can form a first clearance S1 with the outer cylindrical surface 23f of the fixing portion 23. The first clearance S1 is set to a size such that, for example, even when the cylindrical portion 35 is deformed with a reduced diameter, the cylindrical portion 35 does not come into contact with the fixing portion 23. Thereby, since the reduction in diameter deformation of the cylindrical portion 35 is suppressed by the fixing portion 23, the deformation of the top surface portion 34 is suppressed as well.

[0057] In the present embodiment, as shown in FIG. 2, the portion that is the boundary position between the plate-shaped main surface portion 36 and the cylindrical portion 35 having a uniform diameter in the axial direction can be relatively thicker than other portions of the main plate 13 with blades. Here, the so-called "thicker" means that the resin of the fan portion 3 is gathered due to the confluence of each portion constituting the fan portion 3. Hereinafter, this portion will be referred to as the "thick portion 35a".

[0058] In the present 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. Therefore, as shown in FIG. 4, at the location where the root portion of the blade portion 31 in the second axial direction C2 and the root portion on the radially inner side of the main plate portion 32 gather in the thick portion 35a, the thickness can become even greater.

[0059] By forming such a thick portion 35a, in the fan portion 3, the tendency of thermal deformation of the top surface portion 34 and the cylindrical portion 35 provided as the second portion 50 becomes more likely to occur. However, since the reduction in diameter deformation of the cylindrical portion 35 starting from the thick portion 35a is allowed by the first clearance S1, the deformation of the top surface portion 34 is suppressed. In the present embodiment, it can also be said that the above-described annular rib portion 38 and the auxiliary rib portion 39 are provided at positions separated from the cylindrical portion 35, that is, at positions separated from the thick portion 35a.

[0060] [3. Action, Effect] (1) In the centrifugal fan 1 described above, a first clearance S1 is formed between the outer cylindrical surface 43f (outer cylindrical surface 23f) of the first cylindrical portion 43 (fixed portion 23) and the inner cylindrical surface 53f (inner cylindrical surface 35f) of the second cylindrical portion 53 (cylindrical portion 35). Thus, even if the centrifugal fan 1 is used in an environment with a large temperature change, the reduction in diameter deformation of the second cylindrical portion 53 due to the temperature change is allowed, so that the lifting deformation of the second top surface portion 52 (top surface portion 34) caused by the inhibition of the reduction in diameter deformation of the second cylindrical portion 53 can be suppressed. Therefore, the deviation of the center of gravity position of the fan portion 3 can be suppressed.

[0061] Further, the adhesion position between the first portion 40 provided on the rotor 5 and the second portion 50 provided on the fan portion 3 is changed from the positions of the cylindrical portions 43, 53 to the positions of the top surface portions 42, 52. In this way, the second top surface portion 52 adhesively fixed to the first portion 40 (rotor yoke 9) instead of the second cylindrical portion 53 is provided with a second plane 52f (end face 37f) facing the first plane 42f (adhesion surface 22f) and a convex portion 60 protruding in the first axial direction C1 from the second plane 52f and abutting against the first plane 42f. A second clearance S2 is formed by the convex portion 60 between the first plane 42f and the second plane 52f. Then, the first plane 42f and the second plane 52f are adhesively fixed by the adhesive G provided in the second clearance S2, so that the adhesion strength of these planes 42f, 52f is further increased. Therefore, according to the centrifugal fan 1 described above, while ensuring the adhesion strength of the fan portion 3 to the rotor 5, the deviation of the center of gravity position due to thermal deformation can be effectively suppressed.

[0062] (2) When the protruding amount of the convex portion 60 is set to the optimum film thickness of the adhesive G, the first plane 42f and the second plane 52f can be fixed more firmly.

[0063] (3) On the top surface portion 34 serving as the second-day face portion 52, a main surface portion 36 extending radially outward and toward the second axial direction C2 from the second boss portion 33 serving as the second hole portion 51 is provided. Thereby, the fan portion 3 can smoothly extrude the fluid sucked from the first axial direction C1 side along the main surface portion 36 outward in the second axial direction C2 and in the radial direction. Therefore, the blowing efficiency of the fan portion 3 can be improved. In addition, since it is possible to suppress the fluid from swirling radially inside the fan portion 3, noise suppression of the fan portion 3 can be achieved.

[0064] (4) On the top surface portion 34, a rib portion 37 protruding in the second axial direction C2 from the main surface portion 36 and reinforcing the main surface portion 36 is provided. By utilizing the end face 37f of the rib portion 37 as the second plane 52f, it is possible to realize the adhesive fixation of the top surface portion 34 serving as the second-day face portion 52 to the connection face portion 22 serving as the first-day face portion 42 without deliberately providing a portion forming the second plane 52f on the top surface portion 34. In addition, by adding the rib portion 37 to the top surface portion 34, the fluidity of the resin during molding is improved, and the finish accuracy such as the flatness and parallelism of the fan portion 3 can be improved.

[0065] (5) If the rib portion 37 having the end face 37f adhesively fixed to the adhesive surface 22f is provided at a position radially separated from the cylindrical portion 35, it is possible to suppress the reduction in diameter deformation of the cylindrical portion 35 from being inhibited by the rib portion 37. Thereby, it is possible to suppress the force causing the reduction in diameter deformation of the cylindrical portion 35 from being replaced by the upward deformation of the top surface portion 34, and thus it is possible to effectively suppress the deviation of the center of gravity position of the fan portion 3. In addition, if the rib portion 37 is provided at a position separated from the cylindrical portion 35, it is possible to suppress the resin from gathering around the cylindrical portion 35, and thus it is possible to suppress the reduction in diameter deformation of the cylindrical portion 35. The root portion of the cylindrical portion 35 on the main surface portion 36 side is a location where the axial root portion of the blade portion 31 and the radially inner root portion of the main board portion 32 merge. If the rib portion 37 is provided at a position separated from the cylindrical portion 35, it leads to a reduction in the wall thickness of the thick wall portion 35a, that is, it is possible to suppress the reduction in diameter deformation of the cylindrical portion 35, the upward deformation of the top surface portion 34, and the warping deformation of the main board portion 32. From this, it is possible to suppress the deviation of the center of gravity position of the fan portion 3.

[0066] (6) If the rib portion 37 is provided at a position radially separated from the second boss portion 33, the protruding amount of the rib portion 37 with respect to the main surface portion 36 extending radially outward and toward the second axial direction C2 side can be suppressed. Therefore, the moldability of the main plate 13 with blades having the second boss portion 33, the top surface portion 34, and the cylindrical portion 35 as the second portion 50 can be improved. Further, when the annular rib portion 38 is provided at a position separated from the second boss portion 33, the area of the annular end surface 38f of the annular rib portion 38 is enlarged. Therefore, the adhesive area is enlarged and the adhesive strength can be improved.

[0067] (7) In the centrifugal fan 1 described above, the convex portion 60 protrudes from the end surface 37f of the rib portion 37. Thereby, the moldability of the main plate 13 with blades can be improved. In particular, when the main plate 13 with blades is made of resin, if the rib portion 37 and the convex portion 60 are provided separately, a problem may occur in that the portion that becomes the convex portion 60 is not sufficiently filled with resin during molding of the main plate 13 with blades. However, by protruding the convex portion 60 from the end surface 37f of the rib portion 37, such a problem can be suppressed. Further, by protruding the convex portion 60 from the end surface 37f of the rib portion 37, the error in the protruding amount of the convex portion 60 with respect to the end surface 37f of the rib portion 37 can be reduced. Therefore, a space (second clearance S2) for interposing an appropriate amount (film thickness) of the adhesive G between the end surface 37f and the adhesive surface 22f can be secured.

[0068] (8) In the centrifugal fan 1 described above, as the rib portion 37, an annular rib portion 38 and an auxiliary rib portion 39 extending radially outward from the annular rib portion 38 are provided. By providing the auxiliary rib portion 39 on the radially outer side rather than on the radially inner side of the annular rib portion 38, the protruding amount of the auxiliary rib portion 39 with respect to the main surface portion 36 can be suppressed. Further, when the main plate 13 with blades is made of resin, by suppressing the protruding amount of the auxiliary rib portion 39, the shape distortion caused by the difference in the curing time due to the difference in the resin amount during molding can be suppressed.

[0069] In addition, in the centrifugal fan 1 described above, the convex portions 60 protrude from the rectangular end face 39f of the auxiliary rib portion 39. Thereby, the adhesive G can be applied in an annular shape to the annular space (a part of the second clearance S2) between the annular end face 38f of the annular rib portion 38 and the adhesive surface 22f. Therefore, the adhesion balance of the fan portion 3 to the rotor 5 can be made better.

[0070] (9) In the centrifugal fan 1 described above, the three convex portions 60 are provided at equal intervals in the circumferential direction, separated from each other. Thereby, the flattening of the end face 37f with respect to the adhesive surface 22f (arranging the end face 37f parallel to the adhesive surface 22f) can be performed, so that the axial width of the second clearance S2 can be made uniform. Therefore, uneven adhesion of the adhesive G can be suppressed, and the adhesion balance of the fan portion 3 to the rotor 5 can be improved. In addition, if three or more convex portions 60 are provided on the auxiliary rib portion 39 located radially outside the annular rib portion 38, the accuracy of flattening the end face 37f can be further improved.

[0071] (10) When the main plate 13 with blades having the second boss portion 33, the top face portion 34, and the cylindrical portion 35 as the second portion 50 is made of resin and the rotor yoke 9 as the first portion 40 is made of metal, if the convex portion 60 is provided on the side of the main plate 13 with blades, the main plate 13 with blades including the convex portion 60 can be easily molded with a resin having higher moldability than metal.

[0072] [4. Others] The configuration of the centrifugal fan 1 described above is an example and is not limited to the configuration described above. For example, the motor portion 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 face portion 42 and the first cylindrical portion 43, and is not limited to the rotor yoke 9. Also, the first portion 40 does not have to be cup-shaped. The first portion 40 only needs to be made of a material having a smaller linear expansion coefficient than at least the second portion 50, and does not have to be made of metal.

[0073] On the first day, the face portion 42 only needs to have at least a first plane 42f that extends radially outward from the first hole portion 41 and faces the first axial direction C1. That is, the face portion 42 on the first day does not necessarily have to be a face portion that extends radially outward and toward the second axial direction C2 side like the connection face portion 22 described above. Also, the face portion 42 on the first day does not necessarily have to include a plurality of portions 24 to 28 with different extending directions like the connection face portion 22 described above. The first cylindrical portion 43 only needs to extend in the second axial direction C2 from at least the radially outer end of the face portion 42 on the first day, and does not necessarily have to surround the stator core 7 from the radially outer side like the fixing portion 23 described above.

[0074] The fan portion 3 only needs to have at least a plurality of blade portions 31. The shroud 14 may be omitted, and the blade portion 31 and the main board portion 32 do not necessarily have to be integrally formed as a main board 13 with blades. The second portion 50 provided in the fan portion 3 only needs to be at least a portion including a second face portion 52 and a second cylindrical portion 53, and may be a portion (component) provided separately from the main board 13 with blades. The second portion 50 only needs to be made of a material having a larger coefficient of linear expansion than at least the first portion 40, and does not necessarily have to be made of resin. As long as the relationship between the coefficients of linear expansion of the first portion 40 and the second portion 50 is satisfied, both may be made of resin or metal.

[0075] The second face portion 52 only needs to be a portion that extends radially outward from the second hole portion 51 and has a second plane 52f facing the first plane 42f. It does not have to include the main face portion 36 or the rib portion 37 described above, and may simply be a portion that extends perpendicularly to the axial direction from the second hole portion 51 to form a second plane 52f facing the first plane 42f. The configuration of the rib portion 37 is an example, and for example, either the annular rib portion 38 or the auxiliary rib portion 39 may be omitted.

[0076] The first cylindrical portion 43 only needs to be cylindrical with at least an outer cylindrical surface 43f facing radially outward, and the second cylindrical portion 53 only needs to be cylindrical with at least an inner cylindrical surface 53f facing the outer cylindrical surface 43f with a first clearance S1 therebetween. The first cylindrical portion 43 and the second cylindrical portion 53 do not have to be cylindrical. For example, they may be cylindrical with an outer shape that is polygonal when viewed in the axial direction.

[0077] In the centrifugal fan 1 described above, the convex portion 60 protruded from the rectangular end face 39f of the auxiliary rib portion 39 in the second axial direction C2, but the convex portion 60 may protrude from the annular end face 38f of the annular rib portion 38. Further, the convex portion 60 does not have to protrude from the end face 37f. The convex portion 60 may be, for example, a portion that protrudes from the main surface portion 36 in the second axial direction C2 separately from the rib portion 37. The convex portion 60 may be provided on the first top surface portion 42 of the rotor 5.

Explanation of Signs

[0078] 1 Centrifugal fan 3 Fan portion 4 Shaft 5 Rotor 21 First boss portion (first hole portion) 22 Connection surface portion (first top surface portion) 22f Adhesive surface (first plane) 23 Fixing portion (first cylindrical portion) 23f Outer cylindrical surface 31 Blade portion 33 Second boss portion (second hole portion) 34 Top surface portion (second top surface portion) 35 Cylindrical portion (second cylindrical portion) 35f Inner cylindrical surface 36 Main surface portion 37 Rib portion 37f End face (second plane) 38 Annular rib portion 38f Annular end face (second plane) 39 Auxiliary rib portion 39f Rectangular end face (second plane) 40 First part 41 First hole portion 42 First top surface portion 42f First plane 43 First cylindrical part 43f Outer cylindrical surface 50 Second part 51 Second hole part 52 Second end face 52f Second plane 53 Second cylindrical part 53f Inner cylindrical surface 60 Protrusion C1 First axis direction C2 Second axis direction G Adhesive S1 First clearance S2 Second clearance

Claims

1. a first portion provided on a rotor that rotates integrally with a shaft; a second portion provided on a fan portion having a plurality of blade portions and fixed to the rotor, the second portion having a coefficient of linear expansion larger than that of the first portion; the first portion is a first end face portion having a first plane facing a first axial direction in an axial direction of the shaft, extending radially outward from a first hole portion through which the shaft is inserted; a first cylindrical portion extending in a second axial direction opposite to the first axial direction from an end portion on the radially outer side of the first end face portion; the second portion is a second end face portion having a second plane facing the first plane, located in the first axial direction with respect to the first end face portion, extending radially outward from a second hole portion through which the shaft is inserted; a second cylindrical portion extending in the second axial direction from an end portion on the radially outer side of the second end face portion, having an inner cylindrical surface facing an outer cylindrical surface of the first cylindrical portion with a first clearance therebetween; a convex portion protruding in the first axial direction from the first plane and abutting against the second plane is provided on the first end face portion, or a convex portion protruding in the second axial direction from the second plane and abutting against the first plane is provided on the second end face portion; the first plane and the second plane are adhesively fixed by an adhesive provided in a second clearance formed by the convex portion A centrifugal fan characterized by the above.

2. The amount of protrusion of the convex portion with respect to the first plane or the second plane is set to the optimum film thickness of the adhesive. The centrifugal fan according to claim 1, characterized by the above.

3. The second end face portion has a main face portion extending radially outward and in the second axial direction from the second hole portion. The centrifugal fan according to claim 1, characterized by the above.

4. The second end face portion further has a rib portion protruding in the second axial direction from the main face portion to reinforce the main face portion, An end face on the second axial direction side of the rib portion forms the second plane. The centrifugal fan according to claim 3, characterized by the above.

5. The convex portion protrudes from the second plane of the second end face portion. The centrifugal fan according to claim 4, characterized by the above.

6. The rib portion has an annular rib portion that projects from the main surface portion in 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 in the second axial direction and extends radially outward from the annular rib portion. The convex portion projects from an end surface on the second axial direction side of the auxiliary rib portion. The centrifugal fan according to claim 5, characterized in that.

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

8. The rib portion is provided at a position radially separated from the second hole portion. The centrifugal fan according to claim 7, characterized in that.

9. The first part is made of metal. The second part is made of resin. The convex portion is provided on the second main surface portion. The centrifugal fan according to claim 1, characterized in that.

10. At least three of the convex portions are provided on the first main surface portion or the second main surface portion. The at least three convex portions are provided at equal intervals in the circumferential direction of the shaft, spaced apart from each other. The centrifugal fan according to claim 1, characterized in that.

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