(19)
(11)EP 2 090 787 A1

(12)EUROPEAN PATENT APPLICATION
published in accordance with Art. 153(4) EPC

(43)Date of publication:
19.08.2009 Bulletin 2009/34

(21)Application number: 07831348.3

(22)Date of filing:  07.11.2007
(51)Int. Cl.: 
F04D 29/28  (2006.01)
F04D 29/66  (2006.01)
(86)International application number:
PCT/JP2007/071617
(87)International publication number:
WO 2008/059738 (22.05.2008 Gazette  2008/21)
(84)Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR

(30)Priority: 14.11.2006 JP 2006308291

(71)Applicant: Daikin Industries, Ltd.
Osaka 530-8323 (JP)

(72)Inventor:
  • HIGASHIDA, Masahito
    Sakai-shi Osaka 591-8511 (JP)

(74)Representative: Siegert, Georg 
Hoffmann - Eitle Patent- und Rechtsanwälte Arabellastrasse 4
81925 München
81925 München (DE)

  


(54)BOSS STRUCTURE OF IMPELLER OF BLOWER AND IMPELLER OF BLOWER HAVING SAME


(57) To provide a boss structure of an impeller of a blower that is capable of improving the strength of the impeller and an impeller of a blower equipped with the boss structure. A boss structure (1) is a boss structure to which a rotating shaft (106) of a motor (105) that drives an impeller (100) of a blower to rotate is pivotally attached, and the boss structure (1) comprises: a hub (10) that includes a cylindrical portion (12) that extends in the rotating shaft direction; a vibration isolation member (20) that sandwiches the cylindrical portion (12) from both sides in a radial direction; a first boss (31) that supports a portion of the vibration isolation member (20) that contacts one radial direction side of the cylindrical portion (12), the rotating shaft (106) being pivotally attached to the first boss (31); and a second boss (32) that supports a portion of the vibration isolation member (20) that contacts the other radial direction side of the cylindrical portion (12), the second boss (32) integrally rotating with the first boss (31).




Description

TECHNICAL FIELD



[0001] The present invention relates to a boss structure of an impeller of a blower and to an impeller of a blower equipped with the boss structure and particularly to a boss structure to which a rotating shaft of a motor that drives an impeller of a blower to rotate is pivotally attached and to an impeller equipped with the boss structure.

BACKGROUND ART



[0002] Conventionally, there has been a boss structure of an impeller of a blower where, for the purpose of reducing vibration from a motor, a hub of the impeller of the blower is fixedly attached, via a vibration isolation member comprising a rubber material or the like, to an outer peripheral portion of a boss to which a rotating shaft of the motor that drives the impeller to rotate is pivotally attached (e.g., see patent document 1).

[0003] Patent Document 1: JP-A No. 2003-269382

DISCLOSURE OF THE INVENTION



[0004] However, in a boss structure where the hub is fixedly attached to the outer peripheral portion of the boss via the vibration isolation member, the effect of reducing vibration from the motor is high, but when an external force acts on the vibration isolation member because of imbalance of the impeller or the like, deformation of the vibration isolation member arises, whereby the external force becomes even larger, and, as a result, the problem that vibration and noise of the impeller become larger arises. Particularly in regard to deformation of the vibration isolation member in the radial direction, it is desirable to control this as much as possible because this increases vibration of the impeller in the radial direction and leads to a drop in the strength of the impeller.

[0005] It is an object of the present invention to provide a boss structure of an impeller of a blower that is capable of improving the strength of the impeller and an impeller of a blower equipped with the boss structure.

[0006] A boss structure according to a first aspect of the present invention is a boss structure to which a rotating shaft of a motor that drives an impeller of a blower to rotate is pivotally attached, the boss structure comprising: a hub that includes a cylindrical portion that extends in the rotating shaft direction; a vibration isolation member that sandwiches the cylindrical portion from both sides in a radial direction; a first boss that supports a portion of the vibration isolation member that contacts one radial direction side of the cylindrical portion, the rotating shaft being pivotally attached to the first boss; and a second boss that supports a portion of the vibration isolation member that contacts the other radial direction side of the cylindrical portion, the second boss integrally rotating with the first boss. It will be noted that an elastic material such as a rubber material is used as the material of the vibration isolation member.

[0007] In this boss structure, both radial direction sides of the cylindrical portion of the hub contact the vibration isolation member and the vibration isolation member is sandwiched from both sides in the radial direction by the first boss and the second boss, so, for example, in comparison to a conventional boss structure where the hub is simply fixedly attached to the outer peripheral portion of the boss via the vibration isolation member, the amount of displacement of the vibration isolation member in the radial direction with respect to an external force becomes about half.

[0008] Thus, in this boss structure, deformation of the vibration isolation member in the radial direction with respect to an external force can be reduced, so the strength of the impeller can be improved.

[0009] A boss structure according to a second aspect of the present invention is the boss structure according to the first aspect of the present invention, wherein the second boss is integrally molded with the first boss.

[0010] In this boss structure, the first boss and the second boss are integrally molded, so the number of parts configuring the boss structure can be reduced.

[0011] A boss structure according to a third aspect of the present invention is the boss structure according to the first or second aspect of the present invention, wherein the first boss and the second boss form a space that houses the vibration isolation member.

[0012] In this boss structure, the first boss and the second boss form a space that houses the vibration isolation member, so, for example, in a case where the vibration isolation member comprises a rubber material, the rubber material can, in a state where the cylindrical portion of the hub has been disposed in a predetermined position in this space, be injected into or fill the space and be vulcanization-molded, and in a case where the vibration isolation member comprises a resin material that has elasticity, the resin material can, in a state where the cylindrical portion of the hub has been disposed in a predetermined position in this space, be injected into or fill the space and be insert-molded.

[0013] In this manner, in this boss structure, the material configuring the vibration isolation member can be injected into or fill the space that the first boss and the second boss form, such that the vibration isolation member can be integrally molded with the first boss, the second boss and the hub, so manufacture is easy.

[0014] A boss structure according to a fourth aspect of the present invention is the boss structure according to the third aspect of the present invention, wherein an opening that allows the space to be communicated with the outside is formed in the first boss and/or in the second boss.

[0015] In this boss structure, the opening that allows the space that houses the vibration isolation member to communicate with the outside is formed, such that when the vibration isolation member is to be integrally molded with the first boss, the second boss and the hub, the material configuring the vibration isolation member can be injected into or fill the space from the outside, so manufacture becomes even easier.

[0016] An impeller of a blower according to a fifth aspect of the present invention comprises the boss structure according to any of the first to fourth aspects of the invention and an impeller body that is integrated with the hub or is fixed to the hub.

[0017] In this impeller of a blower, the impeller is equipped with the boss structure where both radial direction sides of the cylindrical portion of the hub contact the vibration isolation member and where the vibration isolation member is sandwiched from both sides in the radial direction by the first boss and the second boss, so deformation of the vibration isolation member in the radial direction with respect to an external force can be reduced, and the strength of the impeller can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS



[0018] 

FIG. 1 is a radial direction cross-sectional view of an impeller of a blower equipped with a boss structure pertaining to an embodiment of the present invention.

FIG. 2 is an enlarged view of just the boss structure of FIG. 1.

FIG. 3 is a view describing integrally molding a vibration isolation member with a first boss, a second boss and a hub.

FIG. 4 is a view showing a boss structure pertaining to modification 1 and corresponds to FIG. 2.

FIG. 5 is a view describing integrally molding a vibration isolation member pertaining to modification 1 with a first boss, a second boss and a hub.

FIG. 6 is a view showing a boss structure pertaining to modification 2 and corresponds to FIG. 2.

FIG. 7 is a view showing the boss structure pertaining to modification 2 and corresponds to FIG. 4.


EXPLANATION OF THE REFERENCE NUMERALS



[0019] 
1
Boss Structure
10
Hub
12
Cylindrical Portion
20
Vibration Isolation Member
30a, 30b
Opening
31
First Boss
32
Second Boss
100
Impeller
101
Impeller Body
105
Motor
106
Rotating Shaft
S1
Space

BEST MODE FOR CARRYING OUT THE INVENTION



[0020] Below, an embodiment of a boss structure of an impeller of a blower pertaining to the present invention and of an impeller of a blower equipped with the boss structure will be described on the basis of the drawings.

(1) Configurations of Boss Structure of Impeller of Blower and of Impeller of Blower Equipped with the Boss Structure



[0021] FIG. 1 shows a radial direction cross-sectional view of an impeller 100 of a blower equipped with a boss structure 1 pertaining to an embodiment of the present invention. FIG. 2 shows an enlarged view of just the boss structure 1 of FIG. 1.

[0022] The impeller 100 is an impeller of a double-suction type multiblade blower and is mainly equipped with an impeller body 101 and the boss structure 1. Here, O-O in the drawing is an axis-of-rotation line of the impeller 100. The impeller body 101 is configured such that one end each of numerous blades 103 is fixed to an outer peripheral portion of both sides of a disc-shaped end plate 102 and such that outer peripheral edges of the other ends of these blades 143 are joined together by annular end rings 104. A hub 10 that configures the boss structure 1 is fixed in the center of the end plate 102. It will be noted that, in the present embodiment, the end plate 102 of the impeller body 101 is fixed to the hub 10, but the end plate 102 is not limited to this and may also be integrated with the hub 10.

[0023] The boss structure 1 is a structure to which a rotating shaft 106 of a motor 105 that drives the impeller 1000 to rotate is pivotally attached, and the boss structure 1 is configured as a result of the hub 10 being fixedly attached to a boss 30 via a vibration isolation member 20.

[0024] The hub 10 is, in the present embodiment, a member made of sheet metal and mainly includes an annular portion 11 and a cylindrical portion 12. The annular portion 11 is, in the present embodiment, an annular portion whose outer peripheral end is fixed to the inner peripheral portion of the end plate 102 of the impeller body 101. The cylindrical portion 12 is a cylindrical portion that extends in the direction of the axis of rotation, and, in the present embodiment, the cylindrical portion 12 extends from the inner peripheral end of the annular portion 11 toward one side (here, the motor 105 side) in the rotating shaft direction.

[0025] The vibration isolation member 20 comprises, in the present embodiment, a rubber material or a resin material that has elasticity, and the vibration isolation member 20 is disposed so as to sandwich at least part of the cylindrical portion 12 from both sides in the radial direction. The vibration isolation member 20 includes, in the present embodiment, an inner cylinder portion 21, an outer cylinder portion 22 and an extension portion 23. The inner cylinder portion 21 is a cylindrical portion that contacts the inner peripheral surface of the cylindrical portion 12, and the inner cylinder portion 21 extends from the vicinity of the annular portion side (here, the side opposite the motor 105 side) of the cylindrical portion 12 in the rotating shaft direction to the side opposite the annular portion side (here, the motor 105 side) of the cylindrical portion 12 in the rotating shaft direction. The outer cylinder portion 22 is a cylindrical portion that contacts the outer peripheral surface of the cylindrical portion 12, and the outer cylinder portion 22 extends from the end of the inner cylinder portion 21 on the side opposite the annular portion side in the rotating shaft direction, turns back toward the annular portion 11 side of the cylindrical portion 12 in the rotating shaft direction and extends to the end of the cylindrical portion 12 on the annular portion 11 side in the rotating shaft direction. The extension portion 23 is an annular portion that contacts a surface of the annular portion 11 on one side (here, the motor 105 side) in the rotating shaft direction, and the extension portion 23 extends from the end of the outer cylinder portion 22 on the annular portion 11 side in the rotating shaft direction to a position more on the inner peripheral side than the position where the annular portion 11 is fixed to the end plate 102. Here, the length of the portion of the vibration isolation member 20 where the inner cylinder portion 21 and the outer cylinder portion 22 sandwich the cylindrical portion 12 from both sides in the radial direction is a length L1.

[0026] The boss 30 is, in the present embodiment, a member made of metal and mainly includes a first boss 31 and a second boss 32. The first boss 31 is a circular cylinder-shaped portion that supports the portion (here, the inner cylinder portion 21) of the vibration isolation member 20 that contacts one radial direction side (here, the inner peripheral side in the radial direction) of the cylindrical portion 12, and a through hole 31a in which the rotating shaft 106 is pivotally attached is formed in the first boss 31. Here, the length of the first boss 31 in the rotating shaft direction is a length L2. The second boss 32 is a portion that supports the portion (here, the outer cylinder portion 22) of the vibration isolation member 20 that contacts the other radial direction side (here, the outer peripheral side in the radial direction) of the cylindrical portion 12, and the second boss 32 rotates integrally with the first boss 31. In the present embodiment, the second boss 32 includes an annular portion 32a and a cylindrical portion 32b and is integrally molded with the first boss 31. The annular portion 32a is an annular portion that contacts the end of the inner cylinder portion 21 of the vibration isolation member 20 on the side opposite the annular portion 11 side in the rotating shaft direction and the end of the outer cylinder portion 22 on the side opposite the annular portion 11 side in the rotating shaft direction, and the annular portion 32a extends from a position in the substantial center of the first boss 31 in the rotating shaft direction toward the outer peripheral side in the radial direction. The cylindrical portion 32b is a cylindrical portion that contacts the outer peripheral surface of the outer cylinder portion 22 of the vibration isolation member 20, and the cylindrical portion 32b extends from the end of the annular portion 32a on the outer peripheral side in the radial direction to a position where the cylindrical portion 32b contacts a surface of the extension portion 32 on one side (here, the motor 105 side) in the rotating shaft direction. Additionally, the boss 30 (that is, the first boss 31 and the second boss 32) forms an annular space S 1 that is surrounded by the outer peripheral surface of the first boss 31, the surface of the annular portion 32a of the second boss 32 on the other side (here, the side opposite the motor 105 side) in the rotating shaft direction, and the inner peripheral surface of the annular portion 32b of the second boss 32, and the vibration isolation member 20 is housed in this space S1 in a state where the vibration isolation member 20 sandwiches the cylindrical portion 12 of the hub 10 from both sides in the radial direction. Here, in a case where the length of the portion of the boss 30 (that is, the first boss 31 and the second boss 32) that corresponds to the portion of the vibration isolation member 20 (here, the inner cylinder portion 21 and the outer cylinder portion 22) that sandwiches the hub 10 (here, the cylindrical portion 12) from both sides in the radial direction is L3, this length L3 and the aforementioned length L1 of the portion of the vibration isolation member 20 that sandwiches the hub 10 from both sides in the radial direction have a length that is equal to or greater than 1/4 times the length L2.

(2) Characteristics of Boss Structure of Impeller of Blower of Present Embodiment and of Impeller of Blower Equipped with the Boss Structure



[0027] The boss structure 1 of the present embodiment (the same is also true of the impeller 100 of a blower equipped with this boss structure 1) has the following characteristics. (A)

[0028] In the boss structure 1 of the present embodiment, both radial direction sides of the cylindrical portion 12 of the hub 10 contact the vibration isolation member 20 and the vibration isolation member 20 is sandwiched from both sides in the radial direction by the first boss 31 and the second boss 32, so, for example, in comparison to a conventional boss structure where the hub is simply fixedly attached to the outer peripheral portion of the boss via the vibration isolation member, the amount of displacement of the vibration isolation member 20 in the radial direction with respect to an external force becomes about half, and thus deformation of the vibration isolation member 20 in the radial direction with respect to an external force can be reduced, so the strength of the impeller 100 can be improved.

[0029] Further, the length L1 of the portion of the vibration isolation member 20 that sandwiches the hub 10 from both sides in the radial direction and the length L3 of the portion of the boss 30 that corresponds to the portion of the vibration isolation member 20 that sandwiches the hub 10 from both sides in the radial direction have a length that is equal to or greater than 1/4 times the length L2 of the boss 30 in the rotating shaft direction, so the area in which the hub 10, the vibration isolation member 20 and the boss 30 contact each other can be sufficiently ensured, and the effect of reducing deformation of the vibration isolation member 20 in the radial direction with respect to an external force can be reliably obtained.

[0030] Moreover, the hub 10 (here, part of the annular portion 11) is fixedly attached to the end portion of the boss 30 on the other side (here, the cylindrical portion 32b side of the second boss 32 opposite the motor 105 side) in the rotating shaft direction via the vibration isolation member 20 (here, the extension portion 23), so deformation of the vibration isolation member 20 in the rotating shaft direction (here, the motor 105 side) can be reduced. (B)

[0031] In the boss structure 1 of the present embodiment, the first boss 31 and the second boss 32 are integrally molded, so the number of parts configuring the boss structure can be reduced. (C)

[0032] In the boss structure 1 of the present embodiment, the boss 30 (that is, the first boss 31 and the second boss 32) forms the space S 1 that houses the vibration isolation member 20, so the vibration isolation member 20 can be integrally molded with the boss 30 (that is, the first boss 31 and the second boss 32) and the hub 10 as described below.

[0033] First, as shown in FIG. 3, the cylindrical portion 12 of the hub 10 is disposed in a predetermined position in the space S1 (that is, an annular clearance S2 is disposed between the annular portion 11 of the hub 10 and the end of the cylindrical portion 32b of the second boss 32 on the opposite side of the motor 105 side in the rotating shaft direction and it is ensured that the cylindrical portion 12 of the hub 10 does not contact the outer peripheral surface of the first boss 31 or the inner peripheral surface of the cylindrical portion 32b of the second boss 32). Then, for example, in a case where the vibration isolation member 20 is to be configured by a rubber material, this rubber material can be injected into or fill the space S1 and the clearance S2 and be vulcanization-molded. Further, for example, when the vibration isolation member 20 is to be configured by a resin material that has elasticity, this resin material can be injected into or fill the space S1 and the clearance S2 and be insert-molded. In this manner, in the boss structure 1, the material configuring the vibration isolation member 20 can be injected into or fill the space S1 that the boss 30 (that is, the first boss 31 and the second boss 32) forms and the clearance S2, such that the vibration isolation member 20 can be integrally molded with the first boss 31, the second boss 32 and the hub 10, so manufacture is easy. (D)

[0034] In the boss structure 1 of the present embodiment, an annular opening 30a is formed in the end portion (here, the portion between the end portion of the first boss 31 on the side opposite the motor 105 side and the end portion of the cylindrical portion 32b of the second boss 32 on the side opposite the motor 105 side in the radial direction) of the boss 30 on the other side (here, the side opposite the motor 105 side) in the rotating shaft direction, and the opening 30a makes it easier to dispose the cylindrical portion 12 of the hub 10 in a predetermined position in the space S1 and allows the space S1 that houses the vibration isolation member 20 to be communicated with the outside. In this manner, in this boss structure 1, the opening 30a that allows the space S 1 that houses the vibration isolation member 20 to be communicated with the outside is formed, such that when the vibration isolation member 20 is to be integrally molded with the first boss 31, the second boss 32 and the hub 10 as mentioned above, the material configuring the vibration isolation member 20 can be injected into or fill the space S1 through the opening 30a from the other side in the rotating shaft direction (here, the side opposite the motor 105 side), so manufacture becomes even easier.

[0035] Further, in order to ensure that the material configuring the vibration isolation member 20 can be injected into or fill the space S1 from one side (here, the motor 105 side) in the rotating shaft direction, an opening 30b may also be formed in the annular portion 32a of the second boss 32 of the boss 30, for example, separately from the opening 30a. Thus, the material configuring the vibration isolation member 20 can be injected into or fill the space S1 through the opening 30b from one side (here, the motor 105 side) in the rotating shaft direction without using the opening 30a or can be injected into or fill the space S1 in conjunction with the opening 30a.

(3) Modification 1



[0036] In the preceding embodiment, the boss structure has a structure where the space S 1 that opens to the other side (here, the side opposite the motor 105 side) in the rotating shaft direction is formed in the boss 30 and where the cylindrical portion 12 of the hub 10 is inserted into the space S1 from the side of the boss 30 opposite the motor 105 side, but the boss structure may also have a structure where a space S 1 that opens to one side (here, the motor 105 side) in the rotating shaft direction is formed in the boss 30 and where the cylindrical portion 12 of the hub 10 is inserted into the space S1 from the motor 105 side of the boss 30.

[0037] Below, the boss structure 1 of the present modification will be described using FIG. 4 and FIG. 5.

[0038] The boss structure 1 is configured as a result of the hub 10 being fixedly attached to the boss 30 via the vibration isolation member 20.

[0039] The hub 10 is, in the present modification, a member made of sheet metal and mainly includes an annular portion 11 and a cylindrical portion 12. The annular portion 11 is, in the present modification, an annular portion whose outer peripheral end is fixed to the inner peripheral portion of the end plate 102 of the impeller body 101. The cylindrical portion 12 is a cylindrical portion that extends in the direction of the axis of rotation, and, in the present modification, the cylindrical portion 12 extends from the inner peripheral end of the annular portion 11 toward one side (here, the side opposite the motor 105 side) in the rotating shaft direction.

[0040] The vibration isolation member 20 comprises, in the present modification, a rubber material or a resin material that has elasticity, and the vibration isolation member 20 is disposed so as to sandwich at least part of the cylindrical portion 12 from both sides in the radial direction. The vibration isolation member 20 includes, in the present modification, an inner cylinder portion 21, an outer cylinder portion 22 and an extension portion 23. The inner cylinder portion 21 is a cylindrical portion that contacts the inner peripheral surface of the cylindrical portion 12, and the inner cylinder portion 21 extends from the vicinity of the annular portion side (here, the motor 105 side) of the cylindrical portion 12 in the rotating shaft direction to the side opposite the annular portion side (here, the side opposite the motor 105 side) of the cylindrical portion 12 in the rotating shaft direction. The outer cylinder portion 22 is a cylindrical portion that contacts the outer peripheral surface of the cylindrical portion 12, and the outer cylinder portion 22 extends from the end of the inner cylinder portion 21 on the side opposite the annular portion side in the rotating shaft direction, turns back toward the annular portion 11 side of the cylindrical portion 12 in the rotating shaft direction and extends to the end of the cylindrical portion 12 on the annular portion 11 side in the rotating shaft direction. The extension portion 23 is an annular portion that contacts a surface of the annular portion 11 on one side (here, the side opposite the motor 105 side) in the rotating shaft direction, and the extension portion 23 extends from the end of the outer cylinder portion 22 on the annular portion 11 side in the rotating shaft direction to a position more on the inner peripheral side than the position where the annular portion 11 is fixed to the end plate 102. Here, the length of the portion of the vibration isolation member 20 where the inner cylinder portion 21 and the outer cylinder portion 22 sandwich the cylindrical portion 12 from both sides in the radial direction is a length L1.

[0041] The boss 30 is, in the present modification, a member made of metal and mainly includes a first boss 31 and a second boss 32. The first boss 31 is a circular cylinder-shaped portion that supports the portion (here, the inner cylinder portion 21) of the vibration isolation member 20 that contacts one radial direction side (here, the inner peripheral side in the radial direction) of the cylindrical portion 12, and a through hole 31a in which the rotating shaft 106 is pivotally attached is formed in the first boss 31. Here, the length of the first boss 31 in the rotating shaft direction is a length L2. The second boss 32 is a portion that supports the portion (here, the outer cylinder portion 22) of the vibration isolation member 20 that contacts the other radial direction side (here, the outer peripheral side in the radial direction) of the cylindrical portion 12, and the second boss 32 rotates integrally with the first boss 31. In the present modification, the second boss 32 includes an annular portion 32a and a cylindrical portion 32b and is integrally molded with the first boss 31. The annular portion 32a is an annular portion that contacts the end of the inner cylinder portion 21 of the vibration isolation member 20 on the side opposite the annular portion 11 side in the rotating shaft direction and the end of the outer cylinder portion 22 on the side opposite the annular portion 11 side in the rotating shaft direction, and the annular portion 32a extends from the end of the first boss on the side opposite the annular portion 11 side in the rotating shaft direction toward the outer peripheral side in the radial direction. The cylindrical portion 32b is a cylindrical portion that contacts the outer peripheral surface of the outer cylinder portion 22 of the vibration isolation member 20, and the cylindrical portion 32b extends from the end of the annular portion 32a on the outer peripheral side in the radial direction to a position where the cylindrical portion 32b contacts a surface of the extension portion 32 on one side (here, the side opposite the motor 105 side) in the rotating shaft direction. Additionally, the boss 30 (that is, the first boss 31 and the second boss 32) forms an annular space S1 that is surrounded by the outer peripheral surface of the first boss 31, the surface of the annular portion 32a of the second boss 32 on the other side (here, the motor 105 side) in the rotating shaft direction, and the inner peripheral surface of the annular portion 32b of the second boss 32, and the vibration isolation member 20 is housed in this space S1 in a state where the vibration isolation member 20 sandwiches the cylindrical portion 12 of the hub 10 from both sides in the radial direction. Here, in a case where the length of the portion of the boss 30 (that is, the first boss 31 and the second boss 32) that corresponds to the portion of the vibration isolation member 20 (here, the inner cylinder portion 21 and the outer cylinder portion 22) that sandwiches the hub 10 (here, the cylindrical portion 12) from both sides in the radial direction is L3, this length L3 and the aforementioned length L1 of the portion of the vibration isolation member 20 that sandwiches the hub 10 from both sides in the radial direction have a length that is equal to or greater than 1/4 times the length L2.

[0042] Further, in the boss structure 1 of the present modification also, as shown in FIG. 5, the cylindrical portion 12 of the hub 10 is disposed in a predetermined position in the space S1 (that is, an annular clearance S2 is disposed between the annular portion 11 of the hub 10 and the end of the cylindrical portion 32b of the second boss 32 on the motor 105 side in the rotating shaft direction, and it is ensured that the cylindrical portion 12 of the hub 10 does not contact the outer peripheral surface of the first boss 31 or the inner peripheral surface of the cylindrical portion 32b of the second boss 32), and the material configuring the vibration isolation member 20 is injected into or fills the space S 1 that the boss 30 (that is, the first boss 31 and the second boss 32) forms and the clearance S2, such that the vibration isolation member 20 can be integrally molded with the first boss 31, the second boss 32 and the hub 10. Moreover, the material configuring the vibration isolation member 20 can be injected into or fill the space S1 from the rotating shaft direction side through the annular opening 30a that has been formed in the end portion (here, the portion between the end portion of the first boss 31 on the motor 105 side and the end portion of the cylindrical portion 32b of the second boss 32 on the motor 105 side in the radial direction) of the boss 30 on the other side (here, the motor 105 side) in the rotating shaft direction and the opening 30b that has been formed in the annular portion 32a of the second boss 32 of the boss 30.

[0043] In the boss structure 1 of the present modification that has this configuration also, similar to the preceding embodiment, the strength of the impeller 100 can be improved, and the vibration isolation member 20 can be integrally molded with the boss 30 (that is, the first boss 31 and the second boss 32).

(4) Modification 2



[0044] In the preceding embodiment and modification 1, the boss 30 is a boss where the first boss 31 and the second boss 32 are integrally molded, but as shown in FIG. 6 and FIG. 7, the first boss 31 and the second boss 32 may also be separate members.

[0045] In the boss structure 1 of the present modification that has such a configuration, except for the point that the number of parts configuring the boss structure increases, similar to the preceding embodiment and modification 1, the strength of the impeller 100 can be improved, and the vibration isolation member 20 can be integrally molded with the first boss 31, the second boss 32 and the hub 10.

(5) Other Embodiments



[0046] An embodiment of the present invention and modifications thereof have been described on the basis of the drawings, but the specific configuration is not limited to the embodiment and the modifications thereof and is alterable in a range that does not depart from the gist of the invention.

[0047] For example, in the preceding embodiment and the modifications thereof, the boss structure of the present invention was applied to an impeller of a double-suction type multiblade blower, but the boss structure of the present invention is also applicable to impellers of various blowers, such as a single-suction type multiblade blower, a radial fan, a turbo fan, and a propeller fan.

INDUSTRIAL APPLICABILITY



[0048] By utilizing the present invention, there can be provided a boss structure of an impeller of a blower that is capable of improving the strength of the impeller and an impeller of a blower equipped with the boss structure.


Claims

1. A boss structure (1) to which a rotating shaft (106) of a motor (105) that drives an impeller (100) of a blower to rotate is pivotally attached, the boss structure comprising:

a hub (10) that includes a cylindrical portion (12) that extends in the rotating shaft direction;

a vibration isolation member (20) that sandwiches the cylindrical portion from both sides in a radial direction;

a first boss (31) that supports a portion of the vibration isolation member that contacts one radial direction side of the cylindrical portion, the rotating shaft being pivotally attached to the first boss; and

a second boss (32) that supports a portion of the vibration isolation member that contacts the other radial direction side of the cylindrical portion, the second boss integrally rotating with the first boss.


 
2. The boss structure (1) according to claim 1, wherein the second boss (32) is integrally molded with the first boss (31).
 
3. The boss structure (1) according to claim 1 or 2, wherein the first boss (31) and the second boss (32) form a space (S1) that houses the vibration isolation member (20).
 
4. The boss structure (1) according to claim 3, wherein an opening (30a, 30b) that allows the space (S1) to be communicated with the outside is formed in the first boss (31) and/or in the second boss (32).
 
5. An impeller (100) of a blower comprising:

the boss structure (1) according to any of claims 1 to 4; and

an impeller body (101) that is integrated with the hub (10) or is fixed to the hub.


 




Drawing






















REFERENCES CITED IN THE DESCRIPTION



This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description