Fixing structure and blower

Abstract

To provide a fixing structure capable of suppressing damage of an impeller, and a blower.SOLUTION: A fixing structure according to a preferred embodiment of the present invention is a fixing structure that fixes an impeller and a rotor rotatable about a central axis. The impeller includes a tubular portion arranged radially outside of the rotor, and a top plate portion arranged on the first axial side of the rotor. An end portion of the tubular portion on one side in the axial direction is connected to an end portion of the top plate portion on the outer side in the radial direction. The tubular portion has an adhesive portion that is larger than an outer diameter of the rotor and is fixed by an adhesive. An adhering fixing portion of the tubular portion that is fixed to the rotor by an adhesive is separated from the top plate portion to the other side in the axial direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fixing structure and a blower. [Background technology]

[0002] A blower for cooling and ventilating home appliances, office automation equipment, etc. includes an impeller unit with multiple blades arranged in the circumferential direction, and a motor that rotates the impeller unit. For example, Patent Document 1 describes a blower configured such that a motor is disposed inside a resin impeller unit, and the outer peripheral surface of a metal rotor of the motor is fixed to the inner peripheral surface of the impeller unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-122399 Summary of the Invention [Problem to be solved by the invention]

[0004] Because the resin impeller and the metal rotor have different linear expansion coefficients, the radially extending top plate of the impeller undergoes radial dimensional changes in accordance with the linear expansion coefficients due to temperature fluctuations. Meanwhile, the dimensional changes of the impeller's cylindrical portion, which is bonded to the rotor, are affected by the bond to the rotor. This can result in greater thermal stress being applied to the area where the cylindrical portion and the top plate connect than to other areas. In particular, in configurations where the cylindrical portion and the rotor are bonded near the area where the top plate connects, there is little of the cylindrical portion that can elastically deform without being affected by the bond. This makes it difficult to absorb the stress applied to the area where the top plate connects due to the elastic deformation of the cylindrical portion. This can result in damage to the radially outer edge of the top plate.

[0005] In view of the above circumstances, an object of the present invention is to provide a fixing structure and a blower that can prevent damage to an impeller. [Means for solving the problem]

[0006] One aspect of the fixing structure of the present invention is a fixing structure for fixing an impeller to a rotor rotatable about a central axis. The impeller has a cylindrical tubular portion disposed radially outward of the rotor and a top plate portion disposed on one axial side of the rotor. One axial end of the tubular portion is connected to the radially outer end of the top plate portion. The tubular portion is larger than the outer diameter of the rotor and has an adhesive portion fixed thereto with adhesive. The adhesive portion of the tubular portion fixed to the rotor with the adhesive is spaced from the top plate portion on the other axial side.

[0007] One aspect of the blower of the present invention includes the impeller and the rotor fixed to each other by the above-described fixing structure, and a case that houses the impeller and the rotor, respectively. [Effects of the Invention]

[0008] According to one aspect of the present invention, in a fixing structure and a blower, damage to the impeller can be suppressed. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing a blower according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing a blower according to an embodiment. [Figure 3] FIG. 3 is a perspective view showing a rotor case according to one embodiment. [Figure 4] FIG. 4 is a perspective view showing an impeller according to one embodiment. [Figure 5] FIG. 5 is a first partially enlarged cross-sectional view showing a blower according to an embodiment. [Figure 6] FIG. 6 is a partially enlarged cross-sectional view showing a first step of the blower of the embodiment. [Figure 7] FIG. 7 is a partially enlarged cross-sectional view showing a second step of the blower of the embodiment. [Figure 8] FIG. 8 is a second partially enlarged cross-sectional view showing the blower of the embodiment. [Figure 9] FIG. 9 is a third partially enlarged cross-sectional view showing the blower of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a blower according to an embodiment of the present invention will be described with reference to the drawings. Note that the scope of the present invention is not limited to the following embodiments, and can be modified as desired within the scope of the technical concept of the present invention. In addition, in the following drawings, the scale and number of components may differ from the actual structure in order to make each component easier to understand.

[0011] In the following description, the Z axis is indicated in the figures where appropriate. The Z axis is the direction in which the central axis J of the blower in the embodiment described below extends. The central axis J shown in each figure is a virtual axis. In the following description, the direction in which the central axis J extends, i.e., the direction parallel to the Z axis, is referred to as the "axial direction." The radial direction centered on the central axis J is simply referred to as the "radial direction." The circumferential direction centered on the central axis J is simply referred to as the "circumferential direction." The side of the axial direction toward which the arrow of the Z axis points (+Z side) is referred to as the "one axial side" or "upper side." The side of the axial direction opposite to the side toward which the arrow of the Z axis points (-Z side) is referred to as the "other axial side" or "lower side." Note that the terms "upper side" and "lower side" are simply names used to describe the relative positional relationships of the various parts, and the actual positional relationships may be other than those indicated by these names.

[0012] The circumferential direction is indicated by the arrow θ in each figure. The side of the circumferential direction toward which the arrow θ points (+θ side) is called the "one circumferential side." The opposite side of the circumferential direction to the side toward which the arrow θ points (-θ side) is called the "other circumferential side." The one circumferential side is the side that moves counterclockwise around the central axis J when viewed from above (+Z side). The other circumferential side is the side that moves clockwise around the central axis J when viewed from above.

[0013] 1 includes a case 40, a motor unit 15, and an impeller 60. In this embodiment, the blower 10 is a blower fan that sends air outward in the radial direction by rotating the impeller 60 about a central axis J.

[0014] The case 40 accommodates the motor unit 15 and the impeller 60. The case 40 has a first case portion 41 and a second case portion .

[0015] The first case portion 41 has a first side wall portion 41a, a top wall portion 41b, and a first opening portion 41c. As shown in FIG. 2, the first side wall portion 41a has a generally cylindrical shape extending in the axial direction. The first side wall portion 41a opens downward. The first side wall portion 41a surrounds the upper portion of the impeller 60 from the radially outer side. The top wall portion 41b has a generally annular plate shape extending radially. The radial outer edge of the top wall portion 41b is connected to the upper end of the first side wall portion 41a. The top wall portion 41b is provided with an intake port 41d. The intake port 41d is a hole that penetrates the top wall portion 41b in the axial direction. When viewed in the axial direction, the intake port 41d has a generally circular shape centered on the central axis J. As shown in FIG. 1, the first opening portion 41c opens to one circumferential side (+θ side). As shown in FIG. 2, a portion of the inner surface of first case portion 41 that is positioned radially outward from impeller 60 constitutes an upper portion of air passage 40a.

[0016] As shown in FIG. 1, the second case portion 42 has a second side wall portion 42a, a bottom wall portion 42c, and a second opening 42b. As shown in FIG. 2, the second side wall portion 42a has a generally cylindrical shape extending in the axial direction. The second side wall portion 42a opens upward. The second side wall portion 42a surrounds the lower portion of the impeller 60 from the radially outer side. The upper end of the second side wall portion 42a contacts the lower end of the first side wall portion 41a in the axial direction. The bottom wall portion 42c has a generally annular plate shape extending in the radial direction. The radial outer edge of the bottom wall portion 42c is connected to the lower end of the second side wall portion 42a. A bottom wall hole 42h is provided in the bottom wall portion 42c. The bottom wall hole 42h is a hole that penetrates the bottom wall portion 42c in the axial direction. When viewed in the axial direction, the bottom wall hole 42h has a generally circular shape centered on the central axis J. As shown in FIG. 1, the second opening 42b opens to one circumferential side (+θ side). When viewed in the axial direction, the second opening 42b overlaps with the first opening 41c. The first opening 41c and the second opening 42b form the exhaust port 40b. As shown in FIG. 2, a portion of the inner surface of the second case portion 42 that is located radially outward of the impeller 60 forms a lower portion of the air passage 40a. Air flowing toward one circumferential side in the air passage 40a flows out to the outside of the blower 10 via the exhaust port 40b.

[0017] The motor section 15 is disposed inside the impeller 60. The motor section 15 includes a sleeve 50, a rotor 20, a shaft 23, a stator 30, and a circuit board 70. Thus, the case 40 accommodates the rotor 20 inside.

[0018] The sleeve 50 has a generally cylindrical shape and extends axially about the central axis J. The lower end of the sleeve 50 is fixed to the inner circumferential surface of the bottom wall hole 42h. An upper portion of the inner circumferential surface of the sleeve 50 holds a bearing 92, and a lower portion holds a bearing 91.

[0019] The rotor 20 is rotatable around a central axis J. The impeller 60 and the rotor 20 are fixed to each other by a fixing structure 19. In this embodiment, the fixing structure 19 is a structure that fixes the rotor 20 and the impeller 60. In this embodiment, the rotor 20 is made of metal. The rotor 20 has a rotor case 21 and a magnet 22.

[0020] The rotor case 21 is disposed inside the impeller 60. As shown in FIG. 3, the rotor case 21 is cylindrical and extends in the axial direction around the central axis J. When viewed in the axial direction, the outer peripheral surface of the rotor case 21 is circular. In this embodiment, the outer peripheral surface of the rotor case 21 is the outer peripheral surface of the rotor 20. Therefore, when viewed in the axial direction, the outer peripheral surface of the rotor 20 is circular. The rotor case 21 is open on both the upper and lower sides. As shown in FIG. 2, the shaft 23 and the sleeve 50 are passed through the rotor case 21 in the axial direction. The magnet 22 is fixed to the inner peripheral surface of the rotor case 21. The magnet 22 has a plurality of magnetic poles arranged along the circumferential direction.

[0021] The shaft 23 has a generally cylindrical shape and extends axially along the central axis J. An upper portion of the shaft 23 is fixed to the impeller 60. The shaft 23 is supported by bearings 91 and 92 so as to be rotatable about the central axis J. This allows the shaft 23, the rotor 20, and the impeller 60 to rotate about the central axis J.

[0022] The stator 30 is disposed radially inside the rotor 20. The stator 30 faces the rotor 20 with a gap therebetween in the radial direction. The stator 30 includes a stator core 31, an insulator 32, and a plurality of coils 33.

[0023] The stator core 31 has a substantially circular ring shape centered on the central axis J. The inner peripheral surface of the stator core 31 is fixed to the outer peripheral surface of the sleeve 50. The stator core 31 faces the rotor 20 with a gap therebetween in the radial direction. The insulator 32 is attached to the stator core 31. Each coil 33 is attached to the stator core 31 via the insulator 32. The coils 33 are arranged at intervals from one another in the circumferential direction.

[0024] The circuit board 70 supplies current to each coil 33. The circuit board 70 is disposed below the stator 30. The circuit board 70 is plate-shaped and extends in the radial direction. The circuit board 70 is fixed to the bottom wall portion 42c. The circuit board 70 has a first through hole 70a. The first through hole 70a is a hole that passes through the circuit board 70 in the axial direction. The sleeve 50 and the shaft 23 are passed through the first through hole 70a in the axial direction.

[0025] The impeller 60 has a cup portion 60a, a connecting portion 63, blade portions 64, and an annular portion 65. The cup portion 60a accommodates the motor portion 15 therein. The cup portion 60a is open downward. The cup portion 60a has a top plate portion 61 and a cylindrical portion 62. In this embodiment, the impeller 60 is made of resin.

[0026] The top plate portion 61 has a generally hemispherical shell shape that is convex upward and is centered on the central axis J. The top plate portion 61 is disposed above the rotor 20, i.e., on one axial side (+Z side). The top plate portion 61 has a top plate base portion 61a and multiple positioning portions 61d.

[0027] The top plate base 61a has a generally hemispherical shell shape that is convex upward and is centered on the central axis J. The top plate base 61a covers the rotor 20 from above. The radial outer edge of the top plate base 61a is located radially outward from the rotor 20. The top plate base 61a is provided with an impeller through-hole 61b that passes through the top plate base 61a in the axial direction. When viewed from the axial direction, the impeller through-hole 61b has a generally circular shape centered on the central axis J. An upper portion of the shaft 23 is fixed to the inner circumferential surface of the impeller through-hole 61b.

[0028] As shown in Fig. 4, each positioning portion 61d is a columnar portion that protrudes downward from the top plate base portion 61a. The positioning portions 61d are spaced apart from one another in the circumferential direction. As shown in Fig. 2, each positioning portion 61d contacts the upper end of the rotor case 21 in the axial direction. This determines the axial position of the rotor 20 relative to the impeller 60.

[0029] The cylindrical portion 62 has a cylindrical shape and is disposed radially outward of the rotor 20. In this embodiment, the cylindrical portion 62 has a substantially cylindrical shape that extends in the axial direction around the central axis J. The upper end of the cylindrical portion 62, i.e., the end on one axial side (+Z side), is connected to the radially outer end of the top plate portion 61. The impeller connection portion 60c shown in FIG. 5 is a portion of the impeller 60 where the top plate portion 61 and the cylindrical portion 62 are connected. As shown in FIG. 2, the cylindrical portion 62 has a small diameter portion 62a, an adhesive portion 62c, a storage portion 62e, an opening 62g, and an adhesive fixing portion 62h. The opening 62g opens downward, i.e., to the other axial side (-Z side).

[0030] The small diameter portion 62a is the upper portion of the cylindrical portion 62. The small diameter portion 62a has a cylindrical shape extending in the axial direction. More specifically, the small diameter portion 62a has a substantially cylindrical shape centered on the central axis J. The upper end of the small diameter portion 62a is the upper end of the cylindrical portion 62. The upper end of the small diameter portion 62a is connected to the radially outer end of the top plate portion 61. The small diameter portion 62a is located above the adhesive portion 62c, i.e., on one axial side (+Z side). As shown in FIG. 5, the inner diameter of the small diameter portion 62a is smaller than the inner diameter of the adhesive portion 62c. The inner diameter of the small diameter portion 62a is smaller than the outer diameter of the rotor case 21. In other words, the inner diameter of the small diameter portion 62a is smaller than the outer diameter of the rotor 20. Although not shown, in this embodiment, an adhesive G is disposed between the rotor 20 and the lower portion of the small diameter portion 62a. In this embodiment, the lower portion of the small diameter portion 62a is fixed to the rotor 20 by an adhesive G. The small diameter portion 62a does not have to be fixed to the rotor 20 by an adhesive G.

[0031] According to this embodiment, the inner diameter of small diameter portion 62a is smaller than the inner diameter of adhesive portion 62c. Therefore, in fixing structure 19 of this embodiment, it is easy to reduce the gap between the inner peripheral surface of small diameter portion 62a and the outer peripheral surface of rotor case 21 in the radial direction, which makes it easy to improve the coaxiality between the central axis of impeller 60 and the central axis of rotor 20. Therefore, when blower 10 is operating, it is possible to stabilize the rotation of impeller 60 and the rotation of rotor 20. This makes it possible to suitably suppress noise and vibration when blower 10 is operating.

[0032] According to this embodiment, the inner diameter of small diameter portion 62a is smaller than the outer diameter of rotor 20. Therefore, in fixing structure 19 of this embodiment, rotor 20 can be press-fitted and fixed to impeller 60 by press-fitting rotor 20 into small diameter portion 62a. This more suitably improves the coaxiality between the central axis of impeller 60 and the central axis of rotor 20. Therefore, when blower 10 is operating, the rotation of impeller 60 and the rotation of rotor 20 can each be more suitably stabilized. This more suitably reduces noise and vibration when blower 10 is operating.

[0033] As shown in FIG. 2, the adhesive portion 62c has a substantially cylindrical shape extending in the axial direction around the central axis J. The upper end of the adhesive portion 62c is axially connected to the lower end of the small diameter portion 62a. When viewed in the axial direction, the inner circumferential surface of the adhesive portion 62c is circular. In this embodiment, the adhesive portion 62c annularly surrounds the radially outer side of the rotor 20. As shown in FIG. 5, the inner diameter of the adhesive portion 62c is larger than the outer diameter of the rotor 20. That is, the adhesive portion 62c is larger than the rotor 20. The inner diameter of the adhesive portion 62c is larger than the inner diameter of the small diameter portion 62a. The inner circumferential surface of the adhesive portion 62c faces the outer circumferential surface of the rotor 20 with a radial gap therebetween. An adhesive G is disposed between the rotor 20 and the adhesive portion 62c in the radial direction. The adhesive portion 62c is fixed to the rotor 20 by the adhesive G. Although not shown in the drawings, in the fixing structure 19 of this embodiment, the entire inner circumferential surface of the adhesive portion 62c is fixed to the outer circumferential surface of the rotor 20. As a result, the cylindrical portion 62 is fixed to the rotor 20 by the adhesive G. In other words, the impeller 60 is fixed to the rotor 20 by the adhesive G.

[0034] As shown in FIG. 2, the accommodation portion 62e has a cylindrical shape centered on the central axis J. More specifically, the accommodation portion 62e has a substantially cylindrical shape extending in the axial direction centered on the central axis J. The accommodation portion 62e is located below the adhesive portion 62c, i.e., on the other axial side (-Z side). The upper end of the accommodation portion 62e is axially connected to the lower end of the adhesive portion 62c. The lower end of the accommodation portion 62e is the lower end of the cylindrical portion 62. The accommodation portion 62e surrounds the radially outer side of the rotor 20 in an annular shape. As shown in FIG. 5, the inner circumferential surface of the accommodation portion 62e faces the outer circumferential surface of the rotor 20 with a radial gap therebetween. The inner diameter of the accommodation portion 62e is larger than the inner diameter of the adhesive portion 62c. The volume of the space between the rotor 20 and the accommodation portion 62e is larger than the volume of the space between the rotor 20 and the adhesive portion 62c. An adhesive G is disposed in at least a portion of the space between the rotor 20 and the accommodating portion 62e in the radial direction. In this embodiment, an upper portion of the accommodating portion 62e is fixed to the rotor 20 by the adhesive G. As a result, the cylindrical portion 62 is fixed to the rotor 20 by the adhesive G. The accommodating portion 62e does not have to be fixed to the rotor 20 by the adhesive G.

[0035] In this embodiment, a thermosetting adhesive such as an epoxy resin adhesive, a melamine resin adhesive, a phenol resin adhesive, or a mixture of these adhesives can be used as the adhesive G. In this embodiment, the adhesive G is an epoxy resin adhesive.

[0036] The adhesive fixing portion 62h is a portion of the cylindrical portion 62 that is fixed to the rotor 20 with the adhesive G. In the present embodiment, as described above, although not shown in the drawings, the lower portion of the small diameter portion 62a is fixed to the rotor 20 with the adhesive G. As described above, the entire inner circumferential surface of the adhesive portion 62c is fixed to the rotor 20 with the adhesive G. As described above, the upper portion of the accommodating portion 62e is fixed to the rotor 20 with the adhesive G. Therefore, the upper end of the adhesive fixing portion 62h is the upper end of the portion of the small diameter portion 62a that is fixed to the rotor 20 with the adhesive G. The lower end of the adhesive fixing portion 62h is the lower end of the portion of the accommodating portion 62e that is fixed to the rotor 20 with the adhesive G. The adhesive fixing portion 62h annularly surrounds the radially outer side of the rotor 20.

[0037] In the axial direction, an upper portion of the small diameter portion 62a is disposed between the top plate portion 61 and the adhesive fixing portion 62h. As a result, the adhesive fixing portion 62h is disposed below the top plate portion 61, i.e., away from the top plate portion 61 on the other axial side (-Z side). In this embodiment, the axial distance Lb between the top plate portion 61 and the adhesive fixing portion 62h is 25% or more of the axial dimension Lc of the cylindrical portion 62. The axial distance Lb between the top plate portion 61 and the adhesive fixing portion 62h may be less than 25% of the axial dimension Lc of the cylindrical portion 62. In this embodiment, the axial dimension La of the adhesive fixing portion 62h is 50% or more of the axial dimension Lc of the cylindrical portion 62. The axial dimension La of the adhesive fixing portion 62h may be less than 50% of the axial dimension Lc of the cylindrical portion 62.

[0038] According to this embodiment, the axial dimension La of the adhesive fixing portion 62h is 50% or more of the axial dimension Lc of the cylindrical portion 62. Therefore, it is easy to increase the axial dimension La of the adhesive fixing portion 62h, and therefore it is easy to increase the adhesive area between the adhesive fixing portion 62h and the rotor 20. This makes it possible to suitably increase the adhesive strength between the impeller 60 and the rotor 20. Therefore, it is possible to prevent the impeller 60 from coming off the rotor 20.

[0039] According to this embodiment, the adhesive fixing portion 62h annularly surrounds the radially outer side of the rotor 20. Therefore, the adhesive fixing portion 62h can be adhesively fixed to the rotor 20 all around the circumference. This makes it easier to increase the adhesive area between the adhesive fixing portion 62h and the rotor 20, thereby more preferably increasing the adhesive strength between the impeller 60 and the rotor 20. Therefore, it is possible to more preferably prevent the impeller 60 from coming off the rotor 20.

[0040] As shown in FIG. 2, the connecting portion 63 has a cylindrical shape that extends radially outward toward the bottom. The connecting portion 63 is disposed radially outward from the tubular portion 62. The connecting portion 63 surrounds the tubular portion 62 from the radially outward side. The upper end of the connecting portion 63 is connected to the outer peripheral surface of the tubular portion 62. In the fixing structure 19 of this embodiment, the connecting portion 63 is connected to the surface of the adhesive portion 62c that faces radially outward. Note that the connecting portion 63 may be connected to the surface of the accommodating portion 62e that faces radially outward, or may be connected across the surface of the adhesive portion 62c that faces radially outward and the surface of the accommodating portion 62e that faces radially outward.

[0041] As shown in FIG. 4, the impeller 60 has a plurality of blade portions 64. When viewed in the axial direction, each blade portion 64 protrudes from the radially inner side toward the radially outer side. Each blade portion 64 has a plate shape extending in the axial direction. The blade portions 64 are arranged at intervals from one another in the circumferential direction. As shown in FIG. 2, each blade portion 64 is arranged radially outward from the cylindrical portion 62. More specifically, each blade portion 64 is arranged radially outward from the connecting portion 63. As shown in FIG. 4, the lower end of the radially inner end of each blade portion 64 is connected to the radially outer end of the connecting portion 63. In this way, the connecting portion 63 connects the plurality of blade portions 64 together.

[0042] As shown in Fig. 2, the annular portion 65 has a substantially circular ring shape centered on the central axis J. As shown in Fig. 4, the annular portion 65 connects to the radially outer portions of the upper ends of each of the blades 64. In this way, the annular portion 65 connects the plurality of blades 64 together.

[0043] In this embodiment, impeller 60 rotates toward one circumferential side (+θ side) around central axis J together with rotor 20 and shaft 23. When impeller 60 rotates toward one circumferential side around central axis J, air is taken into blower 10 through intake port 41d shown in Fig. 1, and the air is sent out radially outward and toward one circumferential side from impeller 60 by multiple blades 64, and then sent out to the outside of blower 10 through exhaust port 40b.

[0044] Next, in this embodiment, the rotor fixing process Pf for fixing the rotor 20 to the impeller 60 will be described. The rotor fixing process Pf is part of the assembly process of the blower 10. In this embodiment, the rotor fixing process Pf includes a first process P1 for applying adhesive G to the rotor 20, a second process P2 for inserting the rotor 20 into the impeller 60, and a third process P3 for curing the adhesive G to fix the rotor 20 to the impeller 60. In this specification, the term "workers, etc." includes workers and assembly equipment, etc., who perform each task. Each task may be performed by a worker alone, by an assembly equipment alone, or by a worker and an assembly equipment.

[0045] In the first step P1, adhesive G is applied to the rotor 20, which has the magnets 22 fixed to the rotor case 21 in advance. As shown in FIG. 6 , an operator applies adhesive G to the outer peripheral surface of the rotor case 21, i.e., the outer peripheral surface of the rotor 20. The adhesive G is applied to at least a portion of the outer peripheral surface of the rotor 20 that will radially face the adhesive portion 62c when the rotor 20 is fixed to the impeller 60. The thickness of the adhesive G applied to the outer peripheral surface of the rotor 20, i.e., the radial dimension of the adhesive G, is preferably greater than the difference between the inner diameter of the adhesive portion 62c and the outer diameter of the rotor 20. This allows the adhesive G to fill the gap between the inner peripheral surface of the adhesive portion 62c and the outer peripheral surface of the rotor 20 without leaving any gaps, thereby increasing the adhesive strength between the impeller 60 and the rotor 20. Note that in this embodiment, adhesive G is applied around the entire circumference of the rotor 20, but adhesive G may be applied only to a portion of the circumference of the rotor 20. When the worker applies adhesive G to the rotor 20, the first step P1 is completed.

[0046] In the second step P2, the rotor 20 is inserted into the impeller 60. The worker moves the rotor 20 from the bottom to the top of the impeller 60. As a result, the worker inserts the rotor 20 into the impeller 60 through the opening 62g, as shown in FIG. 7. At this time, a portion of the adhesive G applied to the outer peripheral surface of the rotor 20 is scraped off by the downward-facing surface of the adhesive portion 62c and is contained between the rotor 20 and the accommodating portion 62e. In other words, the excess adhesive G is contained between the rotor 20 and the accommodating portion 62e. The worker inserts the rotor 20 into the impeller 60 until the rotor 20 contacts each positioning portion 61d in the axial direction, and the second step P2 is completed. At this time, the adhesive G is filled between the inner peripheral surface of the adhesive portion 62c and the outer peripheral surface of the rotor 20. The upper portion of the rotor 20 is press-fitted into the small-diameter portion 62a. Although not shown in the drawings, part of the adhesive G gets into the gap between the inner circumferential surface of the lower part of the small diameter portion 62 a and the outer circumferential surface of the rotor 20 .

[0047] As described above, in the first step P1, when the adhesive G is applied only to a portion of the rotor 20 in the circumferential direction, it is preferable to rotate the rotor 20 in the circumferential direction in the second step P2 after inserting the rotor 20 into the impeller 60. This allows the adhesive G to be filled between the adhesive portion 62c and the rotor 20 over the entire circumferential direction.

[0048] In the third step P3, the adhesive G is hardened to fix the rotor 20 to the impeller 60. For example, if the adhesive G is a thermosetting adhesive, the worker fixes the rotor 20 and the impeller 60 to each other using a jig (not shown) while the rotor 20 and each positioning portion 61d are in axial contact with each other, and then heats and hardens the adhesive G in a heating furnace (not shown). As a result, the adhesive fixing portion 62h is adhesively fixed to the rotor 20, and the rotor 20 and the impeller 60 are fixed to each other. Once the adhesive G has hardened and the rotor 20 and the impeller 60 are fixed to each other, the worker removes the rotor 20 and the impeller 60 from the heating furnace, and the third step P3 is completed. When the third step P3 is completed, the rotor fixing step Pf is completed.

[0049] According to this embodiment, the fixing structure 19 is a fixing structure that fixes the rotor 20, which can rotate about the central axis J, and the impeller 60. The impeller 60 has a cylindrical portion 62 arranged radially outward of the rotor 20 and a top plate portion 61 arranged above the rotor 20, i.e., on one axial side (+Z side). The upper end of the cylindrical portion 62 is connected to the radially outer end of the top plate portion 61. The cylindrical portion 62 is larger than the outer diameter of the rotor 20 and has an adhesive portion 62c fixed thereto with adhesive G. An adhesive fixing portion 62h of the cylindrical portion 62, which is fixed to the rotor 20 with adhesive G, is spaced below the top plate portion 61, i.e., on the other axial side (-Z side). When the top plate portion 61 is thermally deformed in the radial direction due to temperature fluctuations, a large thermal stress is applied to the impeller connection portion 60c of the impeller 60, which is a portion where the top plate portion 61 and the cylindrical portion 62 are connected. More specifically, when the top plate portion 61 thermally expands radially outward due to a temperature rise, a thermal stress St1 directed radially outward is applied to the impeller connection portion 60c, as shown in Fig. 8. Furthermore, when the top plate portion 61 thermally contracts radially inward due to a temperature drop, a thermal stress St2 directed radially inward is applied to the impeller connection portion 60c, as shown in Fig. 9. In a configuration in which the vicinity of the upper end of the cylindrical portion 62 is adhesively fixed to the rotor 20, the upper portion of the cylindrical portion 62 is less likely to elastically deform due to thermal stresses St1, St2 applied to the impeller connection portion 60c. Therefore, since the thermal stresses St1, St2 applied to the impeller connection portion 60c are less likely to be absorbed by the elastic deformation of the cylindrical portion 62, there is a risk that the radial outer edge of the top plate portion 61 will be damaged. In contrast, in the fixing structure 19 of this embodiment, as described above, the adhesive-fixing portion 62h of the cylindrical portion 62, which is adhesively fixed to the rotor 20, is spaced axially from the top plate portion 61. Therefore, when thermal stresses St1 and St2 are applied to the impeller connection portion 60c due to temperature fluctuations, the portion of the cylindrical portion 62 above the adhesive-fixing portion 62h elastically deforms. More specifically, as shown in FIG. 8, when thermal stress St1 is applied to the impeller connection portion 60c, the upper portion of the cylindrical portion 62 elastically deforms in direction D1, which is substantially the same direction as the direction of thermal stress St1. Furthermore, as shown in FIG. 9, when thermal stress St2 is applied to the impeller connection portion 60c, the upper portion of the cylindrical portion 62 elastically deforms in direction D2, which is substantially the same direction as the direction of thermal stress St2. As a result, in the fixing structure 19 of this embodiment, the thermal stresses St1 and St2 applied to the impeller connecting portion 60c can be absorbed by elastic deformation of the portion of the cylindrical portion 62 above the adhesive fixing portion 62h, thereby preventing damage to the radial outer edge of the top plate portion 61. Therefore, damage to the impeller 60 can be prevented.

[0050] According to this embodiment, the axial distance Lb between the top plate portion 61 and the adhesive-fixed portion 62h is 25% or more of the axial dimension Lc of the cylindrical portion 62. This makes it easy to increase the distance between the top plate portion 61 and the adhesive-fixed portion 62h. This makes it easy to increase the amount of elastic deformation of the portion of the cylindrical portion 62 above the adhesive-fixed portion 62h when thermal stresses St1 and St2 are applied to the impeller connection portion 60c due to thermal deformation of the top plate portion 61. Therefore, the thermal stresses St1 and St2 applied to the impeller connection portion 60c can be more effectively absorbed by the elastic deformation of the portion of the cylindrical portion 62 above the adhesive-fixed portion 62h, thereby more effectively preventing damage to the radial outer edge of the top plate portion 61. This more effectively prevents damage to the impeller 60.

[0051] According to this embodiment, the cylindrical portion 62 has an opening 62g that opens downward, i.e., toward the other axial side (-Z side), and a cylindrical housing portion 62e located below the adhesive portion 62c. The volume of the space between the rotor 20 and the housing portion 62e is larger than the volume of the space between the rotor 20 and the adhesive portion 62c. This makes it easy to increase the volume of the space between the housing portion 62e and the rotor 20. As described above, in the second step P2 of the rotor fixing step Pf, when the rotor 20, having adhesive G applied to its outer circumferential surface, is inserted into the impeller 60 through the opening 62g, excess adhesive G scraped off by the downward-facing surface of the adhesive portion 62c is contained in the space between the rotor 20 and the housing portion 62e. Therefore, the fixing structure 19 of this embodiment can increase the volume of excess adhesive G that can be contained in the space between the rotor 20 and the housing portion 62e. This prevents excess adhesive G from leaking out of the impeller 60 through the opening 62g. Therefore, when blower 10 is operating, it is possible to prevent hardened excess adhesive G from coming off rotor 20 and impeller 60 and becoming caught between rotor 20 and stator 30, for example. This makes it possible to improve the operational stability of blower 10.

[0052] According to this embodiment, the impeller 60 has a plurality of blades 64 arranged radially outward from the cylindrical portion 62 and a connecting portion 63 connecting the blades 64 together, and the connecting portion 63 is connected to the radially outward surface of the adhesive portion 62c. As described above, the adhesive portion 62c is adhesively fixed to the rotor 20 arranged radially inward. Therefore, when the blower 10 is operating, the centrifugal force acting on each blade 64 and the connecting portion 63 is applied to the adhesive portion 62c of the cylindrical portion 62 that is fixed to the rotor 20. This prevents the cylindrical portion 62 from deforming radially outward due to this centrifugal force. Therefore, when the blower 10 is operating, the rotation of the impeller 60 can be stabilized.

[0053] According to this embodiment, the inner peripheral surface of the adhesive portion 62c and the outer peripheral surface of the rotor 20 are each circular when viewed in the axial direction, and the entire inner peripheral surface of the adhesive portion 62c is adhesively fixed to the outer peripheral surface of the rotor 20. Therefore, because the outer peripheral surface of the rotor 20 is circular when viewed in the axial direction, the fixing structure 19 of this embodiment does not have any protrusions, such as ribs, on the outer peripheral surface of the rotor 20. This makes it possible to easily apply the adhesive G to the outer peripheral surface of the rotor 20 in the first step P1 described above. Therefore, an increase in the number of steps in the first step P1 can be suppressed, and therefore an increase in the number of steps in the rotor fixing step Pf can be suppressed.

[0054] Furthermore, in this embodiment, the inner peripheral surface of the adhesive portion 62c is adhesively fixed to the rotor 20 around the entire circumference in the circumferential direction, which makes it possible to suppress variations in the adhesive strength between the adhesive portion 62c and the rotor 20 in the circumferential direction. This makes it possible to more suitably increase the adhesive strength between the impeller 60 and the rotor 20. Therefore, it is possible to more suitably suppress detachment of the impeller 60 from the rotor 20.

[0055] According to this embodiment, the blower 10 includes the impeller 60 and the rotor 20 fixed to each other by the fixing structure 19, and the case 40 that houses the impeller 60 and the rotor 20. As described above, in the fixing structure 19 of this embodiment, the adhesive fixing portion 62h of the cylindrical portion 62, which is adhesively fixed to the rotor 20, is spaced axially from the top plate portion 61. Therefore, when thermal stresses St1 and St2 are applied to the impeller connection portion 60c due to temperature fluctuations, the portion of the cylindrical portion 62 above the adhesive fixing portion 62h elastically deforms. As a result, the thermal stresses St1 and St2 applied to the impeller connection portion 60c can be absorbed by the elastic deformation of the portion of the cylindrical portion 62 above the adhesive fixing portion 62h, thereby preventing damage to the radial outer edge of the top plate portion 61. This effectively prevents damage to the impeller 60. Therefore, the temperature range in which the fan 10 can be used can be suitably expanded, and the durability of the fan 10 can be suitably improved.

[0056] Although one embodiment of the present invention has been described above, the configurations and combinations thereof in the embodiment are merely examples, and additions, omissions, substitutions, and other modifications of the configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiment. For example, the uses of the blower shown in the above embodiment are not particularly limited.

[0057] At least a portion of the inner diameter of the small diameter portion may be larger than or equal to the inner diameter of the adhesive portion. Furthermore, at least a portion of the inner diameter of the small diameter portion may be larger than or equal to the outer diameter of the rotor. Even in these cases, by arranging the adhesive portion axially away from the top plate portion, damage to the impeller can be suppressed even when temperature fluctuations occur.

[0058] The volume of the space between the rotor and the housing may be smaller than the volume of the space between the rotor and the adhesive portion, or may be the same as the volume of the space between the rotor and the adhesive portion. Even in these cases, by appropriately adjusting the amount of adhesive applied to the outer circumferential surface of the rotor in the first step, it is possible to prevent excess adhesive from leaking out of the impeller through the opening in the impeller.

[0059] The shape of the top plate of the impeller is not limited to the shape of this embodiment, and may be, for example, an annular plate extending in a direction perpendicular to the axial direction. Even in this case, by arranging the adhesive part axially away from the top plate, damage to the impeller can be suppressed even when temperature fluctuations occur.

[0060] The configurations described in this specification can be combined as appropriate within the scope of not contradicting each other.

[0061] The present technology can be configured as follows. (1) A fixing structure for fixing an impeller to a rotor rotatable around a central axis, the impeller having a cylindrical portion arranged radially outward of the rotor and a top plate portion arranged on one axial side of the rotor, an end portion on one axial side of the cylindrical portion connected to an end portion on the radially outer side of the top plate portion, the cylindrical portion having an adhesive portion larger than the outer diameter of the rotor and fixed to the rotor by the adhesive, and an adhesive fixing portion of the cylindrical portion fixed to the rotor by the adhesive spaced apart from the top plate portion on the other axial side. (2) The fixing structure according to (1), wherein the axial distance between the top plate portion and the adhesive fixing portion is 25% or more of the axial dimension of the cylindrical portion. (3) The fixing structure according to (1) or (2), wherein the axial dimension of the adhesive fixing portion is 50% or more of the axial dimension of the cylindrical portion. (4) The fixing structure according to any one of (1) to (3), wherein the adhesive fixing portion surrounds the radially outer side of the rotor in an annular shape. (5) A fixing structure according to any one of (1) to (4), wherein the tubular portion has a tubular small diameter portion located on one axial side of the adhesive portion, and the inner diameter of the small diameter portion is smaller than the inner diameter of the adhesive portion. (6) The fixing structure according to (5), wherein the inner diameter of the small diameter portion is smaller than the outer diameter of the rotor. (7) A fixing structure described in any one of (1) to (6), wherein the cylindrical portion has an opening that opens to the other axial side and a cylindrical accommodating portion that is located on the other axial side of the adhesive portion, and the volume of the space between the rotor and the accommodating portion is larger than the volume of the space between the rotor and the adhesive portion. (8) A fixing structure described in any one of (1) to (7), wherein the impeller has a plurality of blade portions arranged radially outward from the cylindrical portion, and a connecting portion connecting the plurality of blade portions together, and the connecting portion is connected to a surface of the adhesive portion facing radially outward. (9) A fixing structure described in any one of (1) to (8), wherein, when viewed from the axial direction, the inner surface of the adhesive portion and the outer surface of the rotor are each circular, and the entire inner surface of the adhesive portion is adhesively fixed to the outer surface of the rotor. (10) A blower comprising the impeller and the rotor fixed to each other by the fixing structure described in any one of (1) to (9), and a case that houses each of the impeller and the rotor. [Explanation of symbols]

[0062] 10...blower, 19...fixing structure, 20...rotor, 40...case, 60...impeller, 61...top plate portion, 62...cylindrical portion, 62a...small diameter portion, 62c...bonding portion, 62e...accommodation portion, 62g...opening, 62h...bonding fixing portion, 63...connecting portion, 64...blade portion, G...adhesive, J...central axis, La...axial dimension of bonding portion, Lb...axial distance between top plate portion and bonding portion, Lc...axial dimension of cylindrical portion

Claims

1. A fixing structure for fixing a rotor rotatable around a central axis and an impeller, the impeller has a cylindrical portion disposed radially outward of the rotor and a top plate portion disposed on one axial side of the rotor, an end portion on one axial side of the cylindrical portion is connected to an end portion on the radially outer side of the top plate portion, the cylindrical portion is larger than the outer diameter of the rotor and has an adhesive portion fixed thereto by an adhesive; a fixing structure in which an adhesive fixing portion of the cylindrical portion that is fixed to the rotor by the adhesive is spaced apart from the top plate portion on the other axial side;

2. The fixing structure according to claim 1 , wherein the axial distance between the top plate portion and the adhesive fixing portion is 25% or more of the axial dimension of the cylindrical portion.

3. The fixing structure according to claim 1 or 2, wherein the axial dimension of the adhesive fixing portion is 50% or more of the axial dimension of the cylindrical portion.

4. The fixing structure according to claim 1 or 2, wherein the adhesive fixing portion surrounds the outer side of the rotor in a radial direction in an annular shape.

5. the cylindrical portion has a cylindrical small diameter portion located on one axial side of the adhesive portion, The fixing structure according to claim 1 or 2, wherein an inner diameter of the small diameter portion is smaller than an inner diameter of the adhesive portion.

6. The fixing structure according to claim 5 , wherein the inner diameter of the small diameter portion is smaller than the outer diameter of the rotor.

7. the cylindrical portion has an opening that opens to the other axial side, and a cylindrical containing portion that is located on the other axial side of the adhesive portion, The fixing structure according to claim 1 or 2, wherein a volume of a space between the rotor and the housing portion is larger than a volume of a space between the rotor and the adhesive portion.

8. the impeller has a plurality of blade portions disposed radially outward from the cylindrical portion and a connection portion connecting the plurality of blade portions together, The fixing structure according to claim 1 or 2, wherein the connecting portion is connected to a surface of the adhesive portion facing radially outward.

9. When viewed from the axial direction, an inner circumferential surface of the adhesive portion and an outer circumferential surface of the rotor each have a circular shape, 3. The fixing structure according to claim 1, wherein the entire inner peripheral surface of the adhesive portion is adhesively fixed to the outer peripheral surface of the rotor.

10. The impeller and the rotor are fixed to each other by the fixing structure according to claim 1; a case that accommodates the impeller and the rotor, respectively; A blower comprising:

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