JP2009092010A - Centrifugal blower - Google Patents

Abstract

In a centrifugal blower 1, a circulating flow 15 collides with a main flow 17 flowing into an impeller 6 from a suction cylinder 8 to disturb the flow in the centrifugal direction, and the blowing efficiency is lowered. The suction cylinder 8 as a countermeasure does not have excellent workability and maintainability.
A centrifugal blower 1 includes a casing 7 that surrounds an impeller 6. A suction opening 8 has a suction drum 8. A cylindrical portion 9 and a bell whose inner diameter increases from the cylindrical portion 9 toward the upstream side. A mouth-shaped base 10 and a bell mouth-shaped end portion 11 whose inner diameter increases from the cylindrical portion 9 toward the downstream side are divided into two or more of the impeller side and the suction opening 2 in the vicinity of the minimum diameter portion. Since the main plate 27 is composed of a hub mounting plate 30 that inserts and closes the bell mouth-shaped end portion 11 on the downstream side of the suction drum 8, the main plate 27 is formed in the case after the impeller 6 is assembled. The suction cylinder 8 can be attached, and the effect of improving the blowing performance can be expected.
[Selection] Figure 1

Description

  The present invention relates to a centrifugal blower used for an air-conditioning blower, a ventilation blower, or the like.

  Conventionally, this type of centrifugal blower is fixed by sandwiching a plurality of blade plates in an annular shape between a disk-shaped main plate connected to the rotating shaft of an electric motor and a donut-shaped suction shroud that is concentric with the main plate and has a suction port at the center. There has been known one provided with an impeller and a suction cylinder that guides air to the suction port of the suction shroud (see, for example, Patent Document 1).

  Hereinafter, the centrifugal blower will be described with reference to FIG.

  As shown in the figure, the centrifugal blower 101 of Patent Document 1 includes an impeller 103 including a suction shroud 102, a conical suction cylinder 104 that is tapered toward the impeller 103, and a suction cylinder concentric with the suction cylinder 104. A cylindrical mouse piece 106 connected so that an end portion 105 of 104 protrudes inwardly, and the mouse piece 106 is inserted into a suction port 107 of the impeller 103 and fixed. In addition, when the mouse piece 106 and the suction port 107 come into contact with each other due to run-out of the impeller 103 or vibration due to imbalance, or foreign matter contained in the air to be blown is clogged, loss due to friction or generation of wear, The mouse piece 106 and the suction port 107 are configured to maintain a gap 108 so that destruction due to a collision does not occur.

In the above configuration, when the impeller 103 rotates, the air flowing in from the suction drum 104 due to the pressure increasing action of the impeller 103 passes through the mouth piece 106 and flows into the impeller 103 from the suction port 107 to the impeller 103 and changes its direction in the centrifugal direction. However, since a part of the air flowing out from the suction drum 104 forms a separation vortex 109 with the mouse piece 106 at the portion where the suction drum 104 protrudes inside the mouse piece 106, In order to reduce the pressure in the portion and attract the air flow, the air flowing from the suction cylinder 104 in the direction of the rotation axis is urged to smoothly change the direction in the centrifugal direction.
Japanese Patent No. 3325574

  At this time, since the pressure of the air at the suction port 107 is lower than that of the air flowing out from the impeller 103, a part of the air flowing out from the impeller 103 passes through the gap 108 between the mouth piece 106 and the suction port 107 of the impeller 103. A circulation flow 110 is formed which again flows into the suction port 107 of the impeller 103. In such a conventional centrifugal fan 101, when the circulation flow 110 ejected from the gap 108 in the direction of the rotation axis flows into the suction port 107, the suction cylinder 104 is formed. The air flow from the suction cylinder 104 collides with the air flowing in the centrifugal direction, disturbs the flow in the centrifugal direction, and reduces the blowing performance. The circulating flow 110 collides with the air flowing in from the suction cylinder 104 and flows in the centrifugal direction. Therefore, it is required to improve the air blowing efficiency. In addition, measures that can be realized in assembly are required.

  The present invention solves such a conventional problem, and the circulation flow does not disturb the flow in the centrifugal direction by colliding with the main flow flowing into the impeller from the suction drum, and the blowing efficiency can be improved. And it aims at providing the centrifugal blower characterized by the structure excellent in construction property and maintainability.

  In order to achieve the above object, the centrifugal blower of the present invention has an electric motor, a disk-shaped main plate coupled to a rotating shaft of the electric motor, and an outer shell provided with a suction opening for sucking air and a discharge opening for discharging air. A donut-shaped suction shroud concentrically with the main plate and having a suction port for sucking air in the center, an impeller formed by sandwiching a plurality of blades between the main plate and the suction shroud, and an outer suction to the suction shroud suction port A suction cylinder fixed so as to guide air from the opening for use, the downstream end of the suction cylinder is inserted into the impeller through the suction port of the suction shroud, and a gap is provided between the suction cylinder and the suction shroud. In the centrifugal blower, a part of the air that flows out of the impeller flows into the suction port from the gap between the suction drum and the suction shroud. The suction cylinder is directed in the centrifugal direction, and the suction cylinder has a section of a section, and is divided into two or more parts on the impeller side and the suction opening side in the vicinity of the minimum diameter part. And the main plate is a centrifugal blower characterized in that it is constituted by a hub mounting plate that inserts and closes a bell mouth shape portion on the downstream side of the suction drum.

  By this means, a part of the air flowing out from the impeller can be directed to the centrifugal direction in which the circulation flow formed by flowing into the impeller suction port again through the gap between the suction cylinder and the suction shroud is blown out from the gap. , The direction in which the circulating flow blows out can flow along the main flow that flows into the impeller from the suction cylinder and flows in the centrifugal direction, and the circulating flow collides with the main flow, thereby disturbing the flow in the centrifugal direction and reducing the blowing performance. It is possible to obtain a centrifugal blower with improved workability and maintainability in which the suction cylinder can be removed while the impeller can be attached while the blower efficiency can be improved.

  Another means is that the suction cylinder has a diaphragm-shaped cross section, and has a divided portion that is divided into two or more on the impeller side and the suction opening side in the vicinity of the minimum diameter portion, and the main plate is The centrifugal blower is characterized in that it is constituted by a hub mounting plate for inserting and closing the bell mouth shape portion on the downstream side of the suction drum, and the connecting cylindrical portion is attached to the divided portion. The cylindrical part of the joint has an L shape, a tapered shape that contacts obliquely on the suction opening side, a tapered shape that contacts obliquely on the circulating flow side, a molded Z shape, , Molded U-shaped.

  By this means, it is possible to obtain a centrifugal blower with improved workability and maintainability in which the suction drum can be removed with the impeller assembled.

  Another means is that the suction cylinder has a diaphragm-shaped cross section, and has a divided portion that is divided into two or more on the impeller side and the suction opening side in the vicinity of the minimum diameter portion, and the main plate is The centrifugal blower is characterized in that it is constituted by a hub mounting plate for inserting and closing the bell mouth shape portion on the downstream side of the suction drum, and the positioning portion is attached to the divided portion. The positioning part is provided with two or more uneven dowels, provided with two or more slits and convex dowels, or provided with an uneven ring.

  By this means, it is possible to obtain a centrifugal blower with improved workability and maintainability in which the suction drum can be removed with the impeller assembled.

  Further, the other means is that the suction cylinder has a diaphragm-shaped cross section, and has a divided portion that is divided into two or more on the impeller side and the suction opening side in the vicinity of the minimum diameter portion, and the main plate has the suction suction portion. The centrifugal blower is characterized in that it is composed of a hub mounting plate for inserting and closing the bell mouth shape portion on the downstream side of the body, and an H-shaped coupling member molded in the divided portion is attached.

  By this means, it is possible to obtain a centrifugal blower with improved workability and maintainability in which the suction drum can be removed with the impeller assembled.

  According to the present invention, the centrifugal blower can improve the blowing efficiency without colliding with the main flow flowing into the impeller from the suction cylinder and disturbing the flow in the centrifugal direction, and has excellent workability and maintainability. Can provide.

  According to a first aspect of the present invention, in order to achieve the above object, an electric motor and a disk connected to a rotating shaft of the electric motor are provided in an outer shell having a suction opening for sucking air and a discharge opening for discharging air. -Shaped main plate, a donut-shaped suction shroud that is concentric with the main plate and has a suction port for sucking air in the center, an impeller formed by sandwiching a plurality of blades between the main plate and the suction shroud, and suction suction of the suction shroud A suction cylinder fixed to guide air from the outer suction opening of the outer shell, the downstream end of the suction cylinder is inserted into the impeller from the suction opening of the suction shroud, and the suction cylinder and the suction shroud This is a centrifugal blower with a gap in between. A part of the air that flows out of the impeller flows into the suction port from the gap between the suction cylinder and the suction shroud. The suction flow direction from the gap of the ring flow is directed to the centrifugal direction, and the suction cylinder has a constricted cross section, and is divided into two or more on the impeller side and the suction opening side in the vicinity of the minimum diameter portion. The main plate is configured by a hub mounting plate that inserts and closes the bell mouth shape portion on the downstream side of the suction cylinder, and a cylindrical portion of the joint is attached to the divided portion. . The cylindrical part of the joint has an L shape, a tapered shape that contacts obliquely on the suction opening side, a tapered shape that contacts obliquely on the circulating flow side, a molded Z shape, The molded U-shaped one has the effect of improving the workability and maintainability of removing the suction drum while the impeller is assembled.

  The suction cylinder has a narrowed cross section, and has a divided portion that is divided into two or more on the impeller side and the suction opening side in the vicinity of the minimum diameter portion, and the main plate is downstream of the suction cylinder. It is comprised with the hub mounting plate which inserts and closes the bell mouth shape part of this, and set it as the structure which attached the positioning part to the division | segmentation part. The positioning part has two or more concave and convex dowels, two or more slits and convex dowels, and one with concave and convex rings. A centrifugal blower with improved maintainability can be obtained.

  The suction cylinder has a narrowed cross section, and has a divided portion that is divided into two or more on the impeller side and the suction opening side in the vicinity of the minimum diameter portion, and the main plate is downstream of the suction cylinder. It is composed of a hub mounting plate that inserts and closes the bell mouth shape part of the bellows, and has a structure in which an H-shaped coupling member molded in the divided part is attached, and the workability and maintainability that can remove the suction cylinder It has the effect | action of improving.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
As shown in FIG. 1 to FIG. 3, the centrifugal blower 1 includes a suction opening 2 for sucking air on a side surface and a discharge opening 3 for discharging air on another side surface, and an electric motor 4 and a rotating shaft 5 of the motor 4 An impeller 6 that is connected and blows air by rotation of the electric motor 4 and a casing 7 that surrounds the impeller 6 are provided. The suction opening 2 has a suction cylinder 8 composed of a bell mouth shape base portion 10 and a bell mouth shape end portion 11 which are divided into an upstream side and a downstream side. The suction drum 8 includes a cylindrical portion 9, a bell mouth shape base portion 10 whose inner diameter increases from the cylindrical portion 9 toward the upstream side, and a bell mouth shape end portion 11 whose inner diameter increases from the cylindrical portion 9 toward the downstream side. Since it is provided, the minimum inner diameter position is a cylindrical portion 9 integrated with the suction cylinder 8. The downstream end 16 of the suction cylinder 8 is located inside the impeller 6, that is, closer to the impeller 6 than the upper end of the suction shroud 13 and closer to the main plate 27.

  In the above configuration, when the impeller 6 is rotated by the electric motor 4, the outside air communicating with the suction opening 2 is introduced into the impeller 6 through the suction cylinder 8 by the pressure increasing action caused by the rotation of the blade plate 28 of the impeller 6. The air blown out from the impeller 6 is discharged outside the discharge opening 3.

  At this time, since a portion of the suction cylinder 8 is inserted into the impeller 6, the air from the suction cylinder 8 is reliably introduced into the impeller 6, but the impeller is more than the air that has flowed out of the impeller 6. 6 has a lower pressure than the air at the suction port 12, a part of the air flowing out of the impeller 6 flows into the gap 14 between the suction cylinder 8 and the suction shroud 13 to form a circulating flow 15. Since the suction cylinder 8 includes the bell mouth-shaped end portion 11 whose inner diameter increases from the cylindrical portion 9 toward the downstream end 16, the downstream end 16 of the suction cylinder 8 is bent in the centrifugal direction, and the circulation flow 15 is drawn from the gap 14. The direction to blow out can be directed to the centrifugal direction, and therefore, it can be along the main flow 17, and the circulation flow 15 collides with the main flow 17 to inhibit the centrifugal flow from being disturbed and reduce the blowing performance. It is possible to improve the ventilation efficiency.

  At this time, since the suction cylinder 8 is configured to be wound inside the suction shroud 13, it is impossible to assemble the above configuration with the integrated type. Below, the structure and assembly method of the suction cylinder 8 and the impeller 6 will be described.

  The main plate 27 of the impeller 6 includes a hub mounting plate 30 whose central portion is removable. The diameter of the hub mounting plate 30 is larger than the diameter of the bell mouth shaped end portion 11. With the hub mounting plate 30 removed, the bell mouth shaped end portion 11 is inserted into the impeller 6. The hub attachment plate 30 is attached to the main plate 27, and the hub 29 attached to the hub attachment plate 30 and the rotary shaft 5 are connected. The bell mouth shape end portion 11 is connected to the bell mouth shape base portion 10 by the cylindrical portion 9 from the suction opening 2. As shown in FIG. 3, the bell mouth shape base portion 10 and the bell mouth shape end portion 11 are connected by bonding and caulking as in the joint 18, and the cross section is a drawing type, and the impeller 6 is near the minimum diameter portion. The main plate 27 is composed of a hub mounting plate 30 for inserting and closing the bell mouth-shaped end portion 11 on the downstream side of the suction cylinder 8. Therefore, after the impeller 6 is attached to the electric motor 4 and assembled, the suction cylinder 8 can be attached to the case while assembling. The centrifugal blower 1 assembled in this way can be expected to improve the air blowing performance as described above.

  Further, as shown in FIG. 7, an L-shape 22 may be provided in the cylindrical portion 9 of the joint 18, and the bell mouth-shaped end portion 11 may be connected by facing surfaces of the L-shape 22.

  Further, as shown in FIG. 8, the cylindrical portion 9 of the joint 18 is provided with a tapered shape 23 that is obliquely in contact with the suction opening 2 side, and the opposing surfaces of the tapered shape 23 are in contact with the bell mouth shape end portion 11. You may connect with.

  Further, as shown in FIG. 9, a tapered shape 24 that is obliquely contacted on the circulating flow 15 side is provided on the cylindrical portion 9 of the joint 18, and the bell mouth shape portion 9 is connected in a state where the opposing surfaces of the tapered shape 24 are in contact with each other. May be.

  Further, as shown in FIG. 10, a Z-shape 25 molded in the cylindrical portion 9 of the joint 18 may be provided, and the bell mouth-shaped end portion 11 may be connected to the step surface of the Z-shape 25.

  Further, as shown in FIG. 11, a U-shape 26 molded in the cylindrical portion 9 of the joint 18 may be provided, and the bell mouth shape end portion 11 may be inserted into the gap of the U-shape 26 to be connected.

  Further, as shown in FIG. 4, two or more positioning dowels are provided on the cylindrical portion 9 of the joint 18, and the bell mouth-shaped end portion 11 is connected to the dowel of the positioning portion 19 in a state of being fitted. May be.

  Further, as shown in FIG. 5, the cylindrical portion 9 of the joint 18 is provided with two or more positioning portions 20 with slits and convex dowels, and the bell mouth shape end portion 11 is fitted into the slit of the positioning portion 20 until the convex dowels are fitted to the end. You may connect in the state where it was.

  Further, as shown in FIG. 6, a concave / convex ring positioning portion 21 is provided in the cylindrical portion 9 of the joint 18, and the bell mouth shape end portion 11 is connected in a state of being fitted into the concave and convex rings of the positioning portion 21. May be.

  Further, as shown in FIG. 12, an H-shaped coupling member 31 formed on the cylindrical portion 9 of the joint 18 is provided, and the bell mouth-shaped end portion 11 is connected to the gap of the H-shaped coupling member 31 in a state where it is completely inserted. May be.

  The present invention realizes a centrifugal blower that can improve the blowing efficiency without impinging the flow in the centrifugal direction by colliding with the main flow flowing into the impeller from the suction cylinder, and providing a centrifugal blower with good workability. It is.

The front view which shows the centrifugal air blower of Embodiment 1 of this invention. Side sectional view showing the centrifugal blower Sectional drawing which shows attachment of the suction drum of the centrifugal blower Sectional drawing which shows attachment of the suction drum of the centrifugal blower Sectional drawing which shows attachment of the suction drum of the centrifugal blower Sectional drawing which shows attachment of the suction drum of the centrifugal blower Sectional drawing which shows attachment of the suction drum of the centrifugal blower Sectional drawing which shows attachment of the suction drum of the centrifugal blower Sectional drawing which shows attachment of the suction drum of the centrifugal blower Sectional drawing which shows attachment of the suction drum of the centrifugal blower Sectional drawing which shows attachment of the suction drum of the centrifugal blower Sectional drawing which shows attachment of the suction drum of the centrifugal blower Side sectional view showing a conventional centrifugal blower

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Centrifugal blower 2 Suction opening 3 Discharge opening 4 Electric motor 5 Rotating shaft 6 Impeller 7 Casing 8 Suction cylinder 9 Cylindrical part 10 Bell mouth shape base part 11 Bell mouth shape end part 12 Suction port 13 Suction shroud 14 Gap 15 Circulating flow 16 Downstream End 17 Main flow 18 Joint 19 Positioning portion 20 Positioning portion 21 Positioning portion 22 L-shape 23 Taper shape 24 Taper shape 25 Z-shape 26 U-shape 27 Main plate 29 Hub 30 Hub mounting plate 31 H-shaped coupling member

Claims (11)

A donut having an electric motor, a disk-shaped main plate connected to the rotating shaft of the electric motor, and a suction port for concentrating the air concentrically with the main plate in an outer shell provided with a suction opening for sucking air and a discharge opening for discharging air -Shaped suction shroud, an impeller formed by sandwiching a plurality of blades between the main plate and the suction shroud, and a suction cylinder fixed to guide air from the outer suction opening to the suction port of the suction shroud A centrifugal blower in which the downstream end of the suction cylinder is inserted into the impeller from the suction port of the suction shroud, and a gap is provided between the suction cylinder and the suction shroud. The blowing direction from the gap of the circulating flow generated by flowing into the suction port from the gap between the suction cylinder and the suction shroud is directed to the centrifugal direction. And the suction cylinder has a narrowed cross section, and has a divided portion that is divided into two or more on the impeller side and the suction opening side in the vicinity of the minimum diameter portion, and the main plate is formed of the suction cylinder. A centrifugal blower characterized by comprising a hub mounting plate for inserting and closing a bellmouth shaped portion on the downstream side. The centrifugal blower according to claim 1, wherein a cylindrical portion of a joint formed integrally with the divided portion of the suction drum is attached. The centrifugal blower according to claim 1 or 2, wherein two or more concave and convex dowels are provided in the divided part of the suction drum to form a positioning part. The centrifugal blower according to claim 1 or 2, wherein two or more slits and convex dowels are provided in the divided part of the suction cylinder to form a positioning part. 2. The centrifugal blower according to claim 1, wherein a concave / convex ring is provided in a divided portion of the suction drum to form a positioning portion. The centrifugal blower according to claim 1 or 2, wherein a cylindrical portion of an L-shaped joint is provided in a divided portion of the suction drum. The centrifugal blower according to claim 1 or 2, wherein a cylindrical portion of a tapered joint that obliquely contacts the suction cylinder at the suction opening side is provided in the divided portion of the suction cylinder. The centrifugal blower according to claim 1 or 2, wherein a cylindrical portion of a taper-shaped joint that is in contact with the dividing portion of the suction cylinder obliquely on the circulating flow side is provided. The centrifugal blower according to claim 1 or 2, wherein a cylindrical portion formed by a Z-shaped joint is formed in a divided portion of the suction drum. The centrifugal blower according to claim 1 or 2, wherein a cylindrical portion of a U-shaped joint formed in a divided portion of the suction drum is provided. The centrifugal blower according to claim 1 or 2, further comprising an H-shaped coupling member molded at a divided portion of the suction drum.

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