JP2010163871A - Multiblade centrifugal blower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multiblade centrifugal blower capable of suppressing the increase of noise without enlarging the dimensions of a fan casing. <P>SOLUTION: A multiblade impeller 9 is integrally provided with a wide ring 13 at the outer periphery of a blade suction port 10 side end of a blade group 8. The wide ring 13 is disposed on the main plate 6 side from the end of blades 7 and has a width to prevent a circulating flow that circulates passing between the blades 7 from the blade suction port 10 and returning to the blade suction port 10 side. The circulating flow causing turbulent flow that becomes a factor of causing noise, can thereby be prevented by the wide ring 13 with simple constitution without enlarging the dimensions of the fan casing 5. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention provides a multi-blade impeller comprising a group of blades in which a large number of blades are erected on the outer peripheral side of a circular main plate in a scroll-shaped fan casing having a bell mouth-shaped casing suction port. The present invention relates to a multiblade centrifugal blower including a blade suction port facing the casing suction port.

  Conventionally, in this type of multiblade centrifugal blower, various means for reducing noise have been proposed. As an example, a configuration that suppresses a circulating flow between blades at an axial end of an impeller is used. A multiblade centrifugal blower is known (see, for example, Patent Document 1).

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

As shown in the figure, a scroll type fan casing 101 provided with a bell mouth 103 serving as an air suction port, and a multi-blade centrifugal type impeller that is included in the fan casing 101 and has a large number of blades 104 arranged in an annular shape. 102, the suction port 105 of the impeller 102 is disposed to face the bell mouth 103 of the fan casing 101, and the multi-blade centrifugal blower that blows out the air sucked from the suction port 105 from between the blades 104 in the centrifugal direction. A cylindrical body 107 is integrally extended to an axially outer end of a holding ring 106 that is provided at an axial end of the outer periphery of the impeller 102 and integrally holds a large number of blades 104. The circulation flow toward the suction side is suppressed at the axial direction end side.
JP 2007-146709 A

  In such a conventional multiblade centrifugal blower, the axial length of the impeller 102 is increased, the size of the fan casing 101 is increased, and the size of the multiblade centrifugal blower itself has to be increased. is there.

  This invention solves such a conventional subject, and it aims at providing the multiblade centrifugal blower which can suppress the increase in a noise, without enlarging the dimension of a fan casing.

  In order to achieve the above object, the multiblade centrifugal blower of the present invention has a scroll-shaped fan casing having a bell mouth-shaped casing suction port and a large number of blades standing in an annular shape on the outer peripheral side of the circular main plate. A multi-blade centrifugal fan including a multi-blade impeller provided with a set of blades and having a blade suction port opposed to the casing suction port, wherein the multi-blade impeller includes the blade suction of the blade group. A wide ring is integrally provided on the outer periphery of the end portion on the mouth side, and the wide ring is disposed on the main plate side from the end portion of the blade, and passes between the blades from the blade suction port to the blade suction port side. It has a width that prevents the circulating flow from circulating back.

  Another means is to provide an R shape at the outer peripheral end of the wide ring on the blade inlet side.

  Another means is to form a wide C-shaped outer peripheral end of the wide ring on the blade inlet side.

  According to the present invention, the multiblade impeller is integrally provided with a wide ring on the outer periphery of the blade suction port side end of the blade group, and the wide ring is disposed on the main plate side from the blade end, A wide ring that creates a turbulent flow without increasing the size of the fan casing by preventing the circulating flow from passing through the blades and returning to the blade inlet side. Therefore, it is possible to provide a multiblade centrifugal fan that has an effect of suppressing noise increase and increasing fan efficiency.

  In addition, by providing an R shape at the outer peripheral end of the wide ring on the blade suction port side, there is no injury even when touched when cleaning, and it can be maintained without protective equipment. .

  Moreover, cost reduction can be aimed at by making the outer peripheral side edge part of the blade inlet port side of a wide ring into the wide C surface shape.

  In the multi-blade centrifugal fan according to claim 1 of the present invention, the multi-blade impeller is integrally provided with a wide ring on the outer periphery of the blade suction port side of the blade group, and the wide ring extends from the end of the blade to the main plate. Disposed on the side and having a width to prevent a circulating flow from passing through the blades from the blade suction port and returning to the blade suction port side, and passing between the blades from the blade suction port side. It has the effect of preventing the circulating flow that flows to the suction port side.

  Further, the multi-blade centrifugal blower according to claim 2 is provided with an R shape at the outer peripheral end portion of the wide ring on the blade suction port side, and even if touched by hand, the end portion has an R shape so that it is injured. I don't have to.

  The multi-blade centrifugal blower according to claim 3 is such that the outer peripheral side end portion of the wide ring on the blade suction port side has a wide C surface shape, and the wide ring is wide to prevent the circulation flow. However, the amount of material used can be reduced as much as possible by the C-plane shape.

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

(Embodiment 1)
As shown in FIGS. 1 and 2, the multi-blade centrifugal blower has a box-shaped main body frame 3 having an intake port 1 opened at the lower surface and an exhaust port 2 on the side surface, and a bell mouth-shaped casing. A scroll-shaped fan casing 5 having a suction port 4 and a blade group 8 in which a large number of blades 7 are arranged in an annular shape on the outer peripheral side of a circular main plate 6 are provided. The blade suction port 10 is connected to the casing suction port 4. And a multi-blade impeller 9 enclosed in the fan casing 5, and an electric motor 12 that is provided on the main body frame 3 with the rotation shaft 11 in the vertical direction and rotationally drives the multi-blade impeller 9. The impeller 9 is integrally provided with a wide ring 13 at the outer periphery of the blade suction port 10 side end of the blade group 8, and the wide ring 13 is disposed on the main plate 6 side from the end of the blade 7. The blade inlet 1 from the 10 side through the blade 7 It has a width which prevents the circulating flow circulating back to the side.

  As shown in FIG. 3, an R shape 14 is provided at the outer peripheral side end of the wide ring 13 on the blade inlet 10 side, and a wide C surface shape 15 is provided at the other end.

  With the above configuration, when the multiblade centrifugal fan is operated, in the vicinity of the blade suction port 10 of the multiblade impeller 9, an air flow flows from the blade suction port 10 side to the outside through the blades 7, and the blade suction port 10. Although the circulating flow returning to the side tends to flow, the wide ring 13 prevents the circulating flow from flowing, thereby preventing the generation of noise and the generation of turbulent flow that leads to a reduction in blowing efficiency.

  As described above, according to the multiblade centrifugal fan of Embodiment 1, an increase in noise can be suppressed with a simple configuration without increasing the size of the fan casing 5, and a low-noise multiblade centrifugal fan can be provided.

  Moreover, since the R shape 14 is provided in the outer peripheral side edge part by the side of the blade | wing inlet 10 of the wide ring 13, even if it touches with a hand, it will not be injured. In addition, by making the other end portion a wide C-surface shape 15, the amount of material used can be reduced as much as possible while maintaining the function of preventing circulation flow.

  The wide ring of the multiblade impeller according to the present invention can be widely applied to a multiblade centrifugal fan in which a circulating flow is generated.

The longitudinal cross-sectional view which shows the multiblade centrifugal blower of Embodiment 1 of this invention Perspective view of the multiblade impeller of the multiblade centrifugal fan Enlarged view of the multi-blade impeller near the wide ring Sectional view of a conventional multiblade centrifugal blower

4 Casing suction port 5 Fan casing 6 Main plate 7 Blade 8 Blade group 9 Multi-blade impeller 10 Blade suction port 13 Wide ring 14 R shape 15 C surface shape

Claims (3)

A multi-blade impeller having a blade group in which a large number of blades are erected on the outer peripheral side of a circular main plate in a scroll-shaped fan casing having a bell mouth-shaped casing suction port, and the blade suction port A multi-blade centrifugal fan including a wide ring integrally formed on an outer periphery of an end portion of the blade group on the blade suction port side. Is arranged on the main plate side from the end of the blade, and has a width for preventing a circulating flow from the blade suction port through the blades and returning to the blade suction port side. Multi-blade centrifugal blower. The multiblade centrifugal blower according to claim 1, wherein an R shape is provided at an outer peripheral side end of the wide ring on the blade inlet side. The multiblade centrifugal fan according to claim 1 or 2, wherein the outer peripheral side end of the wide ring on the blade suction port side has a wide C surface shape.

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