JP2002039095A - Press hub for sirocco fan - Google Patents

Abstract

(57) [Summary] [Object] To provide a press hub for a sirocco fan that can reduce the number of parts, machining cost, and material cost to achieve cost reduction. [Structure] It is integrally formed by pressing a metal plate.
In a sirocco fan press hub 10 having a disk-shaped flange portion 10A and a cylindrical boss portion 10B extending integrally from the center of the flange portion 10A in a direction perpendicular to the flange surface, an end of the boss portion 10B A D-shaped hole 10a for rotation prevention is formed in the portion. According to the present invention, since the non-rotating D-shaped hole 10a is formed at the end of the boss 10B of the press hub 10 by press working, a non-rotating part and machining as separate parts are not required, and the number of parts and the number of processing steps are reduced. And cost is reduced. Further, since the press hub 10 is integrally formed by pressing a metal plate, the material cost and the processing cost are reduced, and the cost of the press hub 10 can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a press hub for a sirocco fan for mounting an impeller of a sirocco fan to a drive shaft.

[0002]

2. Description of the Related Art A sirocco fan, which is a kind of centrifugal fan, has a cylindrical impeller that is driven to rotate in a casing, and can be operated in a wide flow rate range. Widely used as such.

[0003] The impeller of such a sirocco fan is attached to a drive shaft of an electric motor or the like via a hub fixed to the center of a support plate.

[0004] The hub is formed by forging an aluminum die-cast hub 110 as shown in FIG. 13 or forging, or integrally formed by pressing a steel plate or the like as shown in FIG. Hub 210
No. 7-107996), and the supporting plate 309 is pressed by pressing the supporting plate 309 as shown in FIG.
09 formed integrally with the hub 310 (Japanese Utility Model Application Laid-Open No. 57-16)
No. 4299) is known.

The aluminum die-cast hub 110 shown in FIG. 13 is formed by integrally forming a boss 110B at the center of a flange 110A, and a drive shaft 105 such as a motor is inserted through the boss 110B. Shaft hole 110
a is penetrated by machining. A concave groove 110b is formed on an end surface of the boss 110B.

The hub 110 has a boss 110
B, the drive shaft 105 is passed through a shaft hole 110a penetrating therethrough, and the screw portion 10 protruding from the boss portion 110B of the drive shaft 105
5a through a plate-shaped washer 111
2 and attached to the drive shaft 105. Here, the screw portion 105 a of the drive shaft 105 is formed by cutting a part of the outer periphery flat to be formed into a D-shape, and a D-shaped hole 111 a is formed in the center of the washer 111. Accordingly, the D-shaped screw portion 105a of the drive shaft 105 is fitted into the D-shaped hole 111a of the washer 111, and the washer 1
11 is a concave groove 1 formed in the boss 110B of the hub 110
The hub 110 is prevented from rotating with respect to the drive shaft 105 by being fitted into the hub 10b.

[0007]

However, the die-cast hub 110 shown in FIG. 13 requires a washer 111 as a detent component,
The groove 110b is formed by machining the boss 110B
Therefore, there is a problem that the number of parts and the number of processing steps are increased because of the necessity of forming, and a cost increase is unavoidable. or,
The die-cast hub 110 has a high material cost ratio to the cost, which also increases the cost of the hub 110.

Accordingly, an object of the present invention is to provide a press hub for a sirocco fan that can reduce the number of parts, the processing cost, and the material cost to reduce the cost.

On the other hand, in the case of the hub 210 which is a stamped product shown in FIG.
Weld nut 214 welded to boss 210B of No. 0
And the bolt 215 that is screwed into the boss portion 215.
OB is deformed by welding heat, and the strength is insufficient.

In a hub 310 formed integrally with a support plate 309 shown in FIG. 15, a set screw 315 is screwed into a female screw portion 310a formed into a cylindrical shape by burring. Is pressed against the folded portion 310b of the hub 310 and the folded portion 310b is brought into close contact with the drive shaft 305 to fix the hub 310 to the drive shaft 305. The hub 310 may have insufficient strength or misalignment.

Accordingly, it is an object of the present invention to provide a press hub for a sirocco fan that can be securely mounted on a drive shaft while preventing insufficient strength, misalignment or thermal deformation.

[0012]

In order to achieve the above-mentioned object, the invention according to claim 1 is characterized in that a metal plate is integrally formed by press working to form a disk-shaped flange portion and a flange surface from the center of the flange portion. A press hub for a sirocco fan having a cylindrical boss extending integrally in a direction perpendicular to the boss, wherein a D-shaped hole for preventing rotation is formed at an end of the boss.

Therefore, according to the first aspect of the present invention, since the D-shaped hole for detent is formed at the end of the boss by press working, the detent component and the machining as separate components become unnecessary, and the component is eliminated. The number of points and the number of processing steps are reduced, and the cost is reduced. Further, since the hub is integrally formed by pressing a metal plate, the material cost and the processing cost are reduced, and the cost of the hub is also reduced.

According to a second aspect of the present invention, a disk-shaped flange portion is integrally formed by pressing a metal plate.
In a sirocco fan press hub having a cylindrical boss portion integrally extending in a direction perpendicular to the flange surface from the center of the flange portion, the boss portion is folded and formed into a double cylindrical shape, and It is characterized in that a screw hole is provided.

Therefore, according to the second aspect of the present invention, the boss portion of the hap, which is integrally formed by pressing a metal plate, is folded back and formed into a double cylindrical shape, and a screw hole is formed in a side portion thereof. , By directly pressing the tip of a bolt screwed into a screw hole provided in the boss portion against a drive shaft inserted into the boss portion to fix the hub to the drive shaft and to prevent the hub from rotating with respect to the drive shaft. This prevents the hub from being deformed and causing insufficient strength and misalignment of the hub. Further, since the hub is integrally formed by pressing a metal plate, material costs and processing costs are reduced, and the cost of the hub is reduced.

According to a third aspect of the present invention, a press hub for a sirocco fan is integrally formed into a U-shape in a side view by pressing a metal plate, and a shaft through-hole is coaxially formed in a bracket portion which is separated by a predetermined distance and opposed to each other. It is characterized in that a screw hole is formed in a plane portion connecting the two bracket portions and formed on the upper portion.

Therefore, according to the third aspect of the present invention, the drive shaft is passed through the shaft through hole formed in the opposed bracket portion of the hub, and the screw hole is provided through the flat portion connecting the two bracket portions. The hub can be fixed to the drive shaft by directly pressing the tip of the bolt that is screwed into the drive shaft, and the hub can be prevented from rotating with respect to the drive shaft. No misalignment occurs.
Further, since the hub is integrally formed by pressing a metal plate, material costs and processing costs are reduced, and the cost of the hub is reduced. Further, by changing the diameter of the shaft through-holes formed in the opposed bracket portions of the hub, the hub can be shared by sirocco fans having different sizes (driving shafts having different diameters).

[0018]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

<First Embodiment> FIG. 1 is a front view of a sirocco fan, FIG. 2 is a cut-away side view of the sirocco fan (a cross-sectional view in the direction of arrow A in FIG. 1), and FIG. FIG. 4 is an enlarged sectional view taken along the line CC of FIG. 3, and FIG. 5 is an exploded perspective view showing an assembly structure of the press hub according to the present invention.

The sirocco fan 1 shown in FIGS. 1 and 2 is constituted by rotatably housing a cylindrical impeller 3 in a casing 2 made of sheet metal, and the impeller 3 is attached to one end surface of the casing 2. It is attached to the end of the drive shaft 5 of the electric motor 4 in a cantilever state.

The other end surface of the casing 2 (the electric motor 4
A circular suction port 2a is opened on the surface opposite to the surface on which is attached (see FIG. 1), and a bell mouth shape for guiding air to the impeller 3 is formed around the suction port 2a. Inlet ring 6 is attached. A scroll-shaped flow path is formed in the casing 2, and a rectangular discharge port 2b is opened in an upper part of the casing 2 (see FIG. 2).

The impeller 3 is formed in a cylindrical shape by arranging a plurality of blades (blades) 7 at an equal angular pitch in a circumferential direction, and has a reinforcing ring 8 attached to one end thereof. A disc-shaped support plate (back plate) 9 is attached to the other end. A press hub 10 according to the present invention is fixed to the center of the support plate 9, and the impeller 3 is attached to the drive shaft 5 of the electric motor 4 via the press hub 10.

Here, the press hub 10 according to the present invention
Will be described in detail with reference to FIGS.

The press hub 10 according to the present invention is integrally formed by pressing a metal plate such as an iron plate. The press hub 10 has a disk-shaped flange portion 10A and a flange surface from the center of the flange portion 10A. And has a cylindrical boss portion 10B integrally extending in a perpendicular direction.
The inner diameter of the boss 10B is equal to the drive shaft 5 of the electric motor 4.
Is set slightly larger than the outer diameter of.

Thus, the press hub 1 according to the present embodiment
At 0, a D-shaped hole 10a for preventing rotation is formed integrally with the tip of the boss 10B by press working (see FIGS. 4 and 5). Here, the inner diameter (shaft hole diameter) of the boss 10B and the inner diameter of the D-shaped hole 10a for rotation prevention are set to be the same.

Also, six cylindrical projections 10b are formed by burring on the same circumference of one end surface (the surface on which the boss portion 10B extends) of the flange portion 10A of the press hub 10.
Are protruded integrally at an equal angle pitch (60 ° pitch).

For the deep drawing of a cylinder with a large flange by press working (the flange diameter is twice or more the shaft diameter and the drawing depth is twice or more the shaft diameter), the deep drawing of the boss portion 10B is performed. Since each step of the D-shaped hole 10a for rotation prevention and the cylindrical projection 10b was also performed separately in multiple steps, the press hub 10 was integrally formed by press working.

Next, the mounting structure of the press hub 10 having the above configuration to the support plate 9 and the drive shaft 5 will be described.

As shown in FIG. 3, a circular hole 9a through which a boss 10B of the press hub 10 penetrates is formed at the center of the support plate 9, and a flange 10A of the press hub 10 is formed therearound. Are formed at equal angular pitches (60 ° pitch) on the same circumference to allow the cylindrical projection 10b formed therethrough to penetrate.

The boss 10B of the press hub 10 is passed through the circular hole 9a formed in the center of the support plate 9 as shown in FIG.
A, the cylindrical projections 10b of the press hub 10 are passed through the circular holes 9b formed in the support plate 9 so that the flange portions 10A of the press hub 10 are in close contact with the support plate 9. The press hub 10 is securely fixed to the center portion of the support plate 9 by pressing and spreading the portion protruding from the support plate 9 of the support plate 9 outward, and the boss portion 10B of the press hub 10 penetrates the center portion of the support plate 9. And protrudes inward of the impeller 3.

As described above, the impeller 3 formed by fixing the press hub 10 to the support plate 9 by caulking (eyelet caulking) is attached to the drive shaft 5 of the electric motor 4 as shown in FIG.
And the inlet ring 6 shown in FIG.
After being removed from the casing 2, the impeller 3 is pushed into the casing 2 from the suction port 2a of the casing 2 with the press hub 10 as the tip side, and the drive shaft 5 of the electric motor 4 is passed through the boss 10B of the press hub 10.

Here, a screw 5a is provided at the tip of the drive shaft 5.
Is formed, and a part of the outer periphery of the screw portion 5a is cut flat to form a D-shape (see FIG. 5).
A snap ring 11 as a stopper is fitted at a predetermined position of the drive shaft 5.

In this state, the impeller 3 is further moved forward along the drive shaft 5 until the flange portion 10A of the press hub 10 contacts the snap ring 11 (the electric motor 4).
Side), and the D-shaped screw portion 5a of the drive shaft 5 is passed through the D-shaped hole 10a for rotation prevention formed at the tip of the boss portion 10B of the press hub 10.

Finally, the nut 12 is screwed into a screw portion 5a protruding from the boss 10B of the press hub 10 of the drive shaft 5 and tightened, so that the entire impeller 3 is driven via the press hub 10 by the drive shaft 5. 5, the D-shaped screw portion 5a of the drive shaft 5 is engaged with a detent D-shaped hole 10a formed integrally with the boss portion 10B of the press hub 10, whereby the drive shaft 5 of the impeller 3 is engaged. Is reliably stopped. The nut 12 is provided with a reverse screw, and its tightening direction matches the rotation direction of the drive shaft 5.

As described above, the impeller 3 is
When it is attached to the drive shaft 5 of the electric motor 4 inside, the inlet ring 6 is attached to the periphery of the intake port 2a of the casing 2, and all the assembling work is completed.

When the drive shaft 5 is rotated at a predetermined speed by the drive of the electric motor 4, the impeller 3 mounted on the drive shaft 5 via the press hub 10 has the same speed in the casing 2. With the rotation of the impeller 3, air is introduced from the intake port 2a of the casing 2 into the impeller 3 while being guided by the inlet ring 6,
This air is given kinetic energy by the impeller 3 and pressurized, and then is discharged radially outward from the periphery of the impeller 3 by centrifugal force, and passes through the scroll-shaped flow path in the casing 2 to cause the casing 2 Is discharged from a discharge port 2b to a duct or the like (not shown), thereby ventilating a room or the like.

As described above, in the present embodiment, the detent D-shaped hole 10c is formed at the end of the boss 10B of the press hub 10 by press working. This eliminates the need for mechanical processing of the non-rotating parts and the concave grooves for fitting the non-rotating parts, thereby reducing the number of parts and the number of processing steps of the press hub 10, thereby reducing the cost. That is, according to the present embodiment, the rotation preventing function can be added to the press hub 10 without increasing the weight and increasing the cost.
In the press hub 10, the support to the drive shaft 5 is provided by the boss 10B, and the D-shaped hole 1
0a has only a detent function, so that the drive shaft 5a
Does not affect the positioning accuracy of the press hub 10.

Further, since the press hub 10 is integrally formed by pressing a metal plate, the material cost and the processing cost are reduced as compared with the conventional hub formed by aluminum die casting or forging. Cost can be reduced.

Further, the press hub 10 according to the present embodiment
As described above, since the inner diameter (shaft hole diameter) of the boss 10B and the inner diameter of the detent D-shaped hole 10a are set to be the same as described above, the shape of the tip thread 5a of the drive shaft 5 needs to be stepped. And the structure of the drive shaft 5 can be simplified.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a front view of the press hub according to the present embodiment, and FIG.
FIG. 8 is a partial sectional view showing an assembly structure of the press hub, and FIG. 9 is an exploded perspective view of the same.

The press hub 20 according to the present embodiment is also integrally formed by pressing a metal plate such as an iron plate, and the press hub 20 has a disc-shaped flange portion 20A.
And a cylindrical boss portion 20B extending integrally from the center of the flange portion 20A in a direction perpendicular to the flange surface, but the boss portion 20B is folded inward to form a double cylindrical shape. Have been. A screw hole 20a is formed through a side portion of the boss portion 20B formed in a double cylindrical shape.
The reason why the boss portion 20B is formed in a double cylindrical shape is that the screw hole 2
This is to ensure the effective number of peaks of 0a. The boss 20
The inner diameter of B is set slightly larger than the outer diameter of the drive shaft 5.

Also, six cylindrical projections 20b are equiangularly formed by burring on one end surface of the flange portion 20A of the press hub 20 (the surface opposite to the side from which the boss portion 20B extends). Projections are provided integrally at a pitch (60 ° pitch).

Next, the press hub 20 having the above configuration will be described.
The structure for mounting the support plate 9 and the drive shaft 5 will be described with reference to FIGS.

As shown in FIG. 8, a circular hole 9a through which a boss 20B of the press hub 20 penetrates is formed in the center of the support plate 9, and a flange 20A of the press hub 20 is formed therearound. Are formed at equal angular pitches (60 ° pitch) on the same circumference to allow the cylindrical projection 20b formed therethrough to penetrate.

The boss 20B of the press hub 20 is passed through the circular hole 9a formed in the center of the support plate 9 as shown in FIG.
A, the cylindrical projections 20b of the press hub 20 are brought into close contact with the support plate 9 by passing the cylindrical projections 20b projecting through the circular holes 9b drilled in the support plate 9, and the cylindrical projections of the press hub 20. The press hub 20 is securely fixed to the center portion of the support plate 9 by pressing the portion protruding from the support plate 20b outward and expanding and caulking.

As described above, in order to mount the impeller having the press hub 20 fixed to the support plate 9 by swaging (eyelet swaging) to the drive shaft 5 of the electric motor, the drive shaft 5 is passed through the boss portion 20B of the press hub 20. , Boss 20B
Bolt 21 that is screwed into a screw hole 20a penetrating through the side of
Should be tightened. Then, the flat portion 5b of the drive shaft 5 in which the tip of the bolt 21 is inserted into the boss portion 20B (see FIG. 9).
The press hub 20 (impeller) is fixed to the drive shaft 5, and the press hub 20 (impeller) is reliably prevented from rotating with respect to the drive shaft 5.

As described above, according to the press hub 20 according to the present embodiment, the bolt 21 is tightened and its tip is pressed against the flat portion 5b of the drive shaft 5 to thereby drive the drive shaft 5 of the press hub 20 (impeller). To the drive shaft 5 and the rotation of the drive shaft 5.
Is not deformed and the press hub 20 does not have insufficient strength or misalignment. Further, since welding is not required for the press hub 20, the press hub 20 is not thermally deformed by welding heat.

The press hub 2 according to the present embodiment
Since 0 is also integrally formed by pressing a metal plate,
Material cost and processing cost are reduced, and the press hub 2
0 cost reduction is achieved.

Third Embodiment Next, a third embodiment of the present invention will be described with reference to FIGS. Note that FIG.
FIG. 11 is an exploded perspective view of the sirocco fan, FIG. 11 is a side sectional view of the sirocco fan, and FIG. 12 is an exploded perspective view showing an assembly structure of the press hub according to the present embodiment.

In FIG. 10, reference numeral 3 denotes an impeller formed by arranging a plurality of blades (blades) 7 at a constant angular pitch in a circumferential direction and forming a cylindrical shape, 9 denotes a support plate, and 30 denotes a press hub according to the present invention. A circular hole 9a is formed in the center of the support plate 9 through which the drive shaft 5 of the electric motor passes, and three small-diameter circular holes 9b are formed around the circular hole 9a on the same circumference. Drilled at an angular pitch (120 ° pitch).

Thus, the press hub 3 according to the present embodiment
No. 0 is integrally formed in a U-shape in a side view by pressing a metal plate, and includes a bracket portion 30A, 30B and a pair of bracket portions 3A, 30B facing each other at a predetermined distance.
A plane portion 30C that connects 0A and 30B is provided. Shaft through holes 31 and 32 are formed coaxially in the opposed bracket portions 30A and 30B, and a screw hole 30a (see FIG. 12) is formed in a flat portion 30C connecting the bracket portions 30A and 30B. Three bracket-shaped projections 30b are provided on one bracket portion 30B in the horizontal direction at an equal angular pitch (60 ° pitch) on the same circumference. The inner diameters of the shaft through-holes 31 and 32 formed in the bracket portions 30A and 30B are set slightly larger than the outer diameter of the drive shaft 5. The press hub 30 has screw holes 3
A material having a thickness enough to ensure an effective number of peaks of 0a is used.

Next, the press hub 30 having the above-described configuration will be described.
The structure for mounting the support plate 9 and the drive shaft 5 will be described with reference to FIGS.

In order to attach the press hub 10 to the support plate 9, three claw-shaped projections 30b projecting from the bracket portion 30B of the press hub 30 are passed through the respective circular holes 9b of the support plate 9, and each claw-shaped projection 30b is The press hub 30 is securely fixed to the center of the support plate 9 by pressing and expanding a portion protruding from the support plate 9.

As described above, to mount the impeller 3 (see FIG. 11) formed by fixing the press hub 30 to the support plate 9 by caulking to the drive shaft 5 of the electric motor, the brackets 30A and 30B of the press hub 30 need to be attached. The drive shaft 5 may be passed through the shaft through-holes 31 and 32 formed coaxially, and the bolt 33 screwed into the screw hole 30a provided through the flat portion 30C of the press hub 30 may be tightened. Then, the tip of the bolt 33 is pressed directly against the flat portion 5b of the drive shaft 5, whereby the press hub 30 (the impeller 3) is fixed to the drive shaft 5 and the drive shaft of the press hub 30 (the impeller 3). 5 is reliably stopped.

As described above, according to the press hub 30 according to the present embodiment, the bolt 3
The press hub 30 (impeller 3) can be fixed to the drive shaft 5 and can be prevented from rotating with respect to the drive shaft 5 by tightening and pressing the tip of the press hub 30 against the flat portion 5b of the drive shaft 5. Even if deformed, the press hub 30 will not be misaligned. Also, press hub 30
Does not require welding, the press hub 30 is not thermally deformed by welding heat.

The press hub 3 according to the present embodiment
Since 0 is also integrally formed by pressing a metal plate,
Material cost and processing cost are reduced, and the press hub 3
0 cost reduction is achieved.

Further, in the press hub 30 according to the present embodiment, the diameters of the shaft through holes 31 and 32 formed in the opposed bracket portions 30A and 30B are changed to change the size (of the drive shaft 5). There is an advantage that the press hub 30 can be shared with a sirocco fan having a different diameter.

Although the present invention has been described with reference to the embodiment in which the present invention is applied particularly to the press hub of a single-suction sirocco fan, the present invention can be similarly applied to a press hub of a double-suction sirocco fan. Of course.

[0059]

As is apparent from the above description, claim 1
According to the described invention, the D-shaped hole for detent is formed at the end of the boss by pressing, so that the detent component and machining as separate components are not required, and the number of parts and the number of processing steps are reduced. Cost reduction is achieved. Further, since the hub is integrally formed by pressing a metal plate, the material cost and the processing cost are reduced, and the cost of the hub is also reduced.

According to the second aspect of the present invention, the boss portion of the hap, which is integrally formed by pressing a metal plate, is turned into a double cylindrical shape, and a screw hole is formed in a side portion thereof. , By directly pressing the tip of a bolt screwed into a screw hole provided in the boss portion against a drive shaft inserted into the boss portion to fix the hub to the drive shaft and to prevent the hub from rotating with respect to the drive shaft. This prevents the hub from being deformed and causing insufficient strength and misalignment of the hub. Further, since the hub is integrally formed by pressing a metal plate, material costs and processing costs are reduced, and the cost of the hub is reduced.

Further, according to the third aspect of the present invention, the drive shaft is passed through the shaft through hole formed in the opposite bracket portion of the hub, and the screw hole is provided through the flat portion connecting the two bracket portions. The hub can be fixed to the drive shaft by directly pressing the tip of the bolt that is screwed into the drive shaft, and the hub can be prevented from rotating with respect to the drive shaft. No misalignment occurs.
Further, since the hub is integrally formed by pressing a metal plate, material costs and processing costs are reduced, and the cost of the hub is reduced. Further, by changing the diameter of the shaft through-holes formed in the opposed bracket portions of the hub, the hub can be shared by sirocco fans having different sizes (driving shafts having different diameters).

[Brief description of the drawings]

FIG. 1 is a front view of a sirocco fan.

FIG. 2 is a cutaway side view of the sirocco fan (a cutaway view in the direction of arrow A in FIG. 1).

FIG. 3 is an enlarged sectional view of a portion B in FIG. 2;

FIG. 4 is an enlarged sectional view taken along line CC of FIG. 3;

FIG. 5 is an exploded perspective view showing an assembling structure of the press hub according to the first embodiment of the present invention.

FIG. 6 is a front view of a press hub according to Embodiment 2 of the present invention.

FIG. 7 is a sectional view taken along line DD of FIG. 6;

FIG. 8 is a partial sectional view showing an assembly structure of a press hub according to a second embodiment of the present invention.

FIG. 9 is an exploded perspective view showing an assembly structure of a press hub according to a second embodiment of the present invention.

FIG. 10 is an exploded perspective view of a sirocco fan including a press hub according to Embodiment 3 of the present invention.

FIG. 11 is a side sectional view of a sirocco fan including a press hub according to Embodiment 3 of the present invention.

FIG. 12 is an exploded perspective view showing an assembling structure of a press hub according to Embodiment 3 of the present invention.

FIG. 13 is an exploded perspective view showing an assembly structure of a conventional sirocco fan hub made of aluminum die-cast.

FIG. 14 is a perspective view of a conventional press hub.

FIG. 15 is a sectional view of a conventional press hub.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sirocco fan 10 Press hub 10A Flange part 10a D-shaped hole for rotation prevention 10B Boss part 20 Press hub 20A Flange part 20a Screw hole 20B Boss part 30 Press hub 30A, 30B Bracket part 30a Screw hole 30C Plane part 31, 32 Shaft through hole

Claims (3)

[Claims] 1. A sirocco integrally formed by pressing a metal plate and having a disk-shaped flange portion and a cylindrical boss portion integrally extending from a center of the flange portion in a direction perpendicular to the flange surface. A press hub for a sirocco fan, wherein a D-shaped hole for preventing rotation is formed at an end of the boss. 2. A sirocco integrally formed by press working of a metal plate and having a disk-shaped flange portion and a cylindrical boss portion integrally extending from a center of the flange portion in a direction perpendicular to the flange surface. A press hub for a sirocco fan, wherein the boss portion is folded back and formed into a double cylindrical shape, and a screw hole is provided in a side portion thereof. 3. A metal plate is press-formed to be integrally formed in a U-shape in a side view, and a shaft through-hole is formed coaxially in a bracket portion which is separated by a predetermined distance and opposed to each other.
A press hub for a sirocco fan, wherein a screw hole is formed through a flat portion connecting both bracket portions.