centrifugal fan

Abstract

To provide a centrifugal fan that is improved in airflow performance and has sufficient strength and durability at high speed rotation.SOLUTION: A centrifugal fan in the present disclosure has a main plate provided with an engaging portion at the center of rotation, which engages with a rotating shaft or the like, and a ring on the inlet side of fluid to be sucked. The centrifugal fan has, on the outer peripheral portion of the main plate, blades erected substantially perpendicular to the surface of the ring. The outer diameter of the ring is equal to the outer diameter of the centrifugal fan, and the blades are erected on the surface of the ring on the main plate side. A part of the blade extends outward in the radial direction of the main plate, and the width of the blade in the rotation axis direction gradually decreases toward the center of rotation of the centrifugal fan.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a centrifugal fan (sirocco fan) used in, for example, an air conditioner. [Background technology]

[0002] Patent Document 1 discloses a conventional centrifugal fan. As shown in Fig. 5, this centrifugal fan has an engagement portion 7 arranged in the center of a main plate 5 that engages with a motor shaft (not shown), blades 2 arranged perpendicularly on the outer periphery of the main plate 5, a ring 6 on the outside of the blade suction portion (upper portion), and blades 2 on the outer periphery of the main plate 5-A. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-215324 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a centrifugal fan that can improve suction performance from the center of the fan and ensure the strength of the fan while improving air volume performance by forming a sufficient flow field in the air passage below the main plate. [Means for solving the problem]

[0005] The centrifugal fan of the present disclosure is a centrifugal fan having a main plate with an engaging portion at the center of rotation that engages with a rotating shaft or the like, and a ring on the inlet side of the fluid to be sucked in, with blades erected on the outer periphery of the main plate approximately perpendicular to the surfaces of the main plate and the ring, the outer diameter of the ring being equal to the outer diameter of the centrifugal fan, the blades erected on the surface of the ring facing the main plate, some of the blades extending radially outward from the main plate, and the width of the blades in the direction of the rotational axis gradually decreasing towards the center of rotation of the centrifugal fan. [Effects of the Invention]

[0006] The centrifugal fan according to the present disclosure can ensure the strength of the fan while improving the airflow performance. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1A is a front view of a centrifugal blower according to a first embodiment of the present invention; [Figure 2] (a) is a front view of a centrifugal blower according to a second embodiment of the present invention; (b) is a cross-sectional view of the centrifugal blower; [Figure 3] (a) is a front view of a centrifugal blower according to a third embodiment of the present invention; (b) is a cross-sectional view of the centrifugal blower; [Figure 4] FIG. 10A is a front view of a centrifugal blower according to a fourth embodiment of the present invention; [Figure 5] (a) Front view and (b) cross-sectional view of a conventional centrifugal blower DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments will be described in detail with reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of already well-known matters or redundant description of substantially the same configuration may be omitted.

[0009] The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0010] (Embodiment 1) Hereinafter, the first embodiment will be described with reference to FIG. A first embodiment of the present invention will be described with reference to FIG. 1(a) which is a front view of an impeller 1 of a centrifugal fan, and FIG. 1(b) which is a cross-sectional view of the impeller 1 of a centrifugal fan.

[0011] In Figure 1, the blades 2 are attached vertically to the outer periphery of the main plate 5, and a ring 6 is attached to the blade suction section (upper part) 2-A. The blades 2 are also attached to the outer periphery 5-A of the main plate. The blade suction height H1 (the blade height of the suction section, i.e., the width in the direction of the rotation axis) gradually becomes lower (smaller) toward the center. In other words, H1 > H2, and there is a gradual change. In this way, by placing the blades in the center, the suction performance near the center is improved, and the blowing performance is also improved. Furthermore, the gradual lowering (smaller) attenuates flow turbulence near the center, which also leads to noise reduction.

[0012] (Embodiment 2) A second embodiment of the present invention will be described with reference to FIG. 2(a) which is a front view of the impeller 1 of a centrifugal fan, and FIG. 2(b) which is a cross-sectional view of the impeller 1 of a centrifugal fan.

[0013] The blade suction height H1 (blade height at the suction part, i.e. width in the direction of the rotation axis) is the same as the blade height HR at the inner diameter of the ring (H1 = HB), and gradually becomes lower (smaller) towards the center. In other words, H1 > H2, and there is a gradual change. In this way, since the height (width) becomes gradually lower (smaller) from the same height (width) as the inner diameter of the ring towards the main plate, the air blowing performance is significantly improved near the ring position.

[0014] (Embodiment 3) A third embodiment of the present invention will be described with reference to FIG. 3(a) which is a front view of the impeller 1 of a centrifugal fan, and FIG. 3(b) which is a cross-sectional view of the impeller 1 of a centrifugal fan.

[0015] The blade suction height H1 (the blade height at the suction part, i.e. the width in the direction of the rotation axis) gradually becomes lower (smaller) towards the center. In other words, H1 > H2, and there is a gradual change. This change can be made into an arc or any curve. This ensures optimal suction performance at any height (width), improving air blowing performance.

[0016] (Fourth embodiment) A fourth embodiment of the present invention will be described with reference to FIG. 4(a) which is a front view of the impeller 1 of a centrifugal fan, and FIG. 4(b) which is a cross-sectional view of the impeller 1 of a centrifugal fan.

[0017] In the blades 2 attached vertically to the outer periphery of the main plate 5 in Figure 4, a ring 6 is attached to the outside of the blade suction section (upper part) 2-A. The blade suction height H1 (the blade height of the suction section, i.e., the width in the direction of the rotation axis) gradually decreases (reduced) toward the center. In other words, H1 > H2, and there is a gradual change. In this way, by placing the blade in the center, the suction performance near the center is improved, and the airflow performance is also improved. Furthermore, blade 2-B is placed below main plate 5, i.e., on the opposite side from the suction part. This creates a sufficient flow field in the airflow path below the main plate, improving airflow performance. [Industrial Applicability]

[0018] The present disclosure can be applied to centrifugal fans installed in air conditioners, dehumidifiers, air purifiers, etc., which can improve blowing performance and reduce noise. [Explanation of symbols]

[0019] 1 Sirocco fan (centrifugal fan) 2 blades 5 Main plate 6 Ring

Claims

1. a centrifugal fan comprising: a main plate having an engaging portion at the center of rotation that engages with a rotation shaft; and a ring on the inlet side of a fluid to be sucked in; blades arranged on the outer periphery of the main plate and standing approximately perpendicular to the surfaces of the main plate and the ring, wherein the outer diameter of the ring is equal to the outer diameter of the centrifugal fan; the blades are arranged on the surface of the ring facing the main plate, and some of the blades extend radially outward from the main plate; the width of the blades in the direction of the rotation axis gradually decreases towards the center of rotation of the centrifugal fan; and the shape of the inlet side end of the blade is curved when viewed from the front.

2. 2. The centrifugal fan according to claim 1, wherein the width of the blade in the direction of the rotation axis is greatest at a position where the blade contacts the inner diameter portion of the ring.

3. 3. The centrifugal fan according to claim 1, wherein blades are also provided on a surface of the main plate opposite to the surface on the ring side.

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