EP2090787B1

EP2090787B1 - Boss structure of impeller of blower and impeller of blower having same

Info

Publication number: EP2090787B1
Application number: EP07831348.3A
Authority: EP
Inventors: Masahito Higashida
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 2006-11-14
Filing date: 2007-11-07
Publication date: 2020-01-01
Anticipated expiration: 2027-11-07
Also published as: WO2008059738A1; CN101542127B; ES2779524T3; EP2090787A1; JP4063308B1; JP2008121610A; EP2090787A4; CN101542127A

Description

The present invention relates to a boss structure, attachable pivotally to a rotating shaft of a motor for driving, rotationally, an impeller of a blower.
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).
Patent Document 1: JP-A No. 2003-269382
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.
United States patent publication no. US 3,409,489 describes a method of making a resilient hub assembly, the assembly lacking optimised strength with regard to the mounting of a fan spider on the hub.
It is therefore desirable 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.
The invention provides a boss structure attachable pivotally to a rotating shaft of a motor for driving, rotationally, an impeller of a blower, 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 an inner cylinder portion of the vibration isolation member, which inner cylinder portion contacts the inner peripheral side, in the radial direction, of the cylindrical portion, the rotating shaft being attachable pivotally to the first boss; and a second boss that supports an outer cylinder portion of the vibration isolation member, which outer cylinder portion contacts the outer peripheral side, in the radial direction, of the cylindrical portion, the second boss being arranged to rotate integrally with the first boss, wherein the first boss and the second boss form a space that houses the vibration isolation member and sandwiches the cylindrical portion of the hub.
The second boss is optionally integrally molded with the first boss. In this boss structure, the number of parts configuring the boss structure can be reduced.
The first boss and the second boss form a space that houses the vibration isolation member. In this boss structure, 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. 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.
Optionally, an opening that allows the space to be communicated with the outside is formed in the first boss and/or in the second boss. 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.
Herein is disclosed an impeller of a blower comprising any one of the above boss structures and an impeller body that is integrated with the hub or is fixed to the hub. 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.
In order that the invention will be more readily understood, embodiments thereof will now be described, given by way of example only, in relation to the drawings, and in which:-

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

EXPLANATION OF THE REFERENCE NUMERALS

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

In the boss structure of an embodiment of the invention, 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.
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.
Below, a boss structure and 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

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.
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 103 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.
The boss structure 1 is a structure to which a rotating shaft 106 of a motor 105 that drives the impeller 100 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.
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.
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.
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 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 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

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) 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.
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.
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) 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) 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 S1 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.
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) 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 S1 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.

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

In the preceding embodiment, the boss structure has a structure where the space S1 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 S1 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.
Below, the boss structure 1 of the present modification will be described using FIG. 4 and FIG. 5.
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.
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.
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.
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.
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 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. 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.
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

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.
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

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 without departing from the scope of the claimed invention.
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.
By utilizing embodiments of 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

A boss structure (1) attachable pivotally to a rotating shaft (106) of a motor (105) for driving, rotationally, an impeller (100) of a blower, 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 an inner cylinder portion (21) of the vibration isolation member, which inner cylinder portion contacts the inner peripheral side, in the radial direction, of the cylindrical portion, the rotating shaft being attachable pivotally to the first boss; and

a second boss (32) that supports an outer cylinder portion (22) of the vibration isolation member, which outer cylinder portion contacts the outer peripheral side, in the radial direction, of the cylindrical portion, the second boss being arranged to rotate integrally with the first boss,

wherein the first boss and the second boss form a space (S1) that houses the vibration isolation member and sandwiches the cylindrical portion of the hub.
The boss structure according to Claim 1, wherein the second boss is integrally molded with the first boss.
The boss structure according to Claim 1 or Claim 2, wherein an opening (30a, 30b) that allows the space to be communicated with the outside is formed in the first boss and/or in the second boss.
The boss structure according to Claim 3 when dependent on Claim 2, wherein a portion of the vibration isolation member that sandwiches the hub from both sides in the radial direction has a length (L1) and the integrally-molded first and second bosses has another length (L2) in the rotating shaft direction, and the first-mentioned length is equal to, or greater than, one quarter of the other length.
An impeller (100) of a blower, comprising:
the boss structure according to any one of Claims 1 to 4; and

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