JP2005264734A

JP2005264734A - Turbo fan

Info

Publication number: JP2005264734A
Application number: JP2004074177A
Authority: JP
Inventors: Masakazu Shimamoto; 昌和島本
Original assignee: Nidec Servo Corp
Current assignee: Nidec Advanced Motor Corp
Priority date: 2004-03-16
Filing date: 2004-03-16
Publication date: 2005-09-29

Abstract

PROBLEM TO BE SOLVED: To realize silencing by suppressing turbulent flow of air near the peripheral edge of a suction port in a turbo fan. SOLUTION: In this turbo fan, a shroud edge is arranged in overlapping proximity to the outer peripheral side of a bellmouth edge. When the axial height b1 of a multiblade impeller is 1, the axial height (b1-b2) of a shroud is formed within a range of 0.27-0.31, and when the outer diameter D2 of the multiblade impeller is 1, the inlet end inner diameter D1 of the shroud is formed within a range of 0.81-0.85. When the inlet end inner diameter D1 of the shroud is 1, a clearance S between the inlet end inner peripheral surface of the shroud and the outer peripheral surface of the bellmouth tip edge formed at a scroll casing is formed within a range of 0.009-0.011, and when the outer diameter D2 of the multiblade impeller is 1, an overlap quantity P of the inlet edge of the shroud and the bellmouth tip edge is formed within a range of 0.009-0.011. COPYRIGHT: (C)2005,JPO&NCIPI

Description

本発明はターボファン、特に吸込口における乱流を抑止し静音化の実現が可能なターボファンに関する。 The present invention relates to a turbofan, and more particularly to a turbofan capable of suppressing turbulent flow at a suction port and realizing noise reduction.

軸方向に開口する吸込口と、円周方向に開口する吐出口を有し、環状内周面とインペラ外周端縁とで形成される通風路の広さが、上流側から下流側に向かって順次拡大する形状を備えるスクロールケーシングと、該スクロールケーシングに内装配置される回転自在の多翼羽根車とを有するターボファンは周知の技術であるので詳細は省くが、図３は従来技術に成るターボファンの例を示す要部断面略図である。 There is a suction port that opens in the axial direction and a discharge port that opens in the circumferential direction, and the width of the ventilation path formed by the annular inner peripheral surface and the outer peripheral edge of the impeller is from the upstream side toward the downstream side. A turbofan having a scroll casing having a shape that expands sequentially and a rotatable multi-blade impeller disposed in the scroll casing is a well-known technique, so that details are omitted, but FIG. It is principal part sectional schematic drawing which shows the example of a fan.

流入する気流を整流する目的で、ケーシングの側面に形成された吸込口に端縁断面が円弧状を成すベルマウスが形成されると共に、内装される多翼羽根車のベルマウスに対向する側の端縁には、ベルマウスに連接するようにこれも円弧状断面を示すシュラウドが形成されている。 For the purpose of rectifying the inflowing airflow, a bell mouth having an arcuate cross section is formed at the suction port formed on the side surface of the casing, and on the side facing the bell mouth of the multi-blade impeller to be installed. A shroud having an arcuate cross section is formed on the end edge so as to be connected to the bell mouth.

特開平１１−３２４９９１号公報）(Japanese Patent Laid-Open No. 11-324991)

上述の如き従来の構成は、吸込口周縁のベルマウスと、これに連接するシュラウド形成による整流効果は認められれるが、十分とはいえず、改善の余地を残していた。 In the conventional configuration as described above, the rectifying effect by the bell mouth around the suction port and the shroud connected to the bell mouth is recognized, but it is not sufficient, and there is room for improvement.

ケーシング吸込口周縁に形成されたベルマウスに対向する、多翼羽根車のシュラウドの入口端縁が、前記ベルマウス先端縁の外周側で重なり・近接するように形成配置され、 The inlet edge of the shroud of the multi-blade impeller facing the bell mouth formed on the peripheral edge of the casing suction port is formed and arranged so as to overlap and approach the outer peripheral side of the bell mouth tip edge,

好ましくは、前記多翼羽根車の軸方向高さｂ１を１としたとき、シュラウドの軸方向高さ（ｂ１−ｂ２）が、０．２７〜０．３１の範囲に形成され、 Preferably, when the axial height b1 of the multiblade impeller is 1, the axial height (b1-b2) of the shroud is formed in the range of 0.27 to 0.31.

加えて、前記多翼羽根車の外径Ｄ２を１としたとき、シュラウドの入口端内径Ｄ１が、０．８１〜０．８５の範囲に形成され、 In addition, when the outer diameter D2 of the multi-blade impeller is set to 1, the shroud inlet end inner diameter D1 is formed in a range of 0.81 to 0.85,

更に加えて、前記シュラウドの入口端内径Ｄ１を１としたとき、該シュラウド入口端内周面とスクロールケーシングに形成されたベルマウス先端縁の外周面との隙間Ｓが、０．００９〜０．０１１の範囲に形成され、 In addition, when the inner diameter D1 of the inlet end of the shroud is 1, a clearance S between the inner peripheral surface of the shroud inlet end and the outer peripheral surface of the bell mouth tip edge formed in the scroll casing is 0.009 to 0.00. 011 is formed,

更に加えて、前記多翼羽根車の外径Ｄ２を１としたとき、シュラウドの入口端縁と、前記ベルマウス先端縁との重なり量Ｐが、０．００９〜０．０１１の範囲に形成される。 In addition, when the outer diameter D2 of the multi-blade impeller is 1, the overlapping amount P between the shroud inlet edge and the bell mouth tip edge is formed in the range of 0.009 to 0.011. The

上述の如き本願発明に成るターボファンは、吸込口近傍での乱流の抑制をもたらし、静音化を実現している。 The turbofan according to the present invention as described above suppresses turbulent flow in the vicinity of the suction port, and achieves noise reduction.

図２は上述本願発明に成る構成での性能改善の例を示し、図（ａ）は従来技術構成での性能：破線表示と本願構成での性能：実線表示で、 FIG. 2 shows an example of performance improvement in the configuration according to the present invention described above, and FIG. 2A is a performance in the prior art configuration: broken line display and performance in the present configuration: solid line display

同図（ｂ）は、最大風量の７５％近傍において、従来構造での性能を１として、ｂ2／ｂ1をパラメータとしたときの性能の変化を示すもので、ノイズは改善領域にあり、風量はほぼ同等で、ｂ2／ｂ1が０．７もしくはこれよりわずかに小さい時ノイズの極小値があり、風量の低下は上記割合が０．６近傍で顕著になっていることが確認されている。 (B) shows the change in performance when the performance of the conventional structure is 1 and b2 / b1 is a parameter in the vicinity of 75% of the maximum airflow. The noise is in the improvement region, and the airflow is It is confirmed that there is a minimum value of noise when b2 / b1 is 0.7 or slightly smaller than this, and it is confirmed that the reduction of the air volume is remarkable in the vicinity of 0.6.

以下図面によって本発明の実施例を説明する。 Embodiments of the present invention will be described below with reference to the drawings.

図１は本発明に成るターボファンのケーシングと内装される多翼羽根車とを略示する要部断面図で、ケーシングに形成されたベルマウスと、内装される多翼羽根車のシュラウドとの対向の様子を示すものである。 FIG. 1 is a cross-sectional view schematically showing a turbofan casing and a multi-blade impeller according to the present invention. A bell mouth formed in the casing and a shroud of the multi-blade impeller built in the casing are shown in FIG. It shows the state of opposition.

図に見るように、本願発明の構成は、ベルマウス端縁の外周側にシュラウド端縁内周面が重なり近接するように配置される。 As shown in the figure, the configuration of the present invention is arranged such that the inner peripheral surface of the shroud edge overlaps and is close to the outer peripheral side of the bell mouth edge.

多翼羽根車の軸方向高さｂ１を１としたとき、シュラウドの軸方向高さ（ｂ１−ｂ２）が、０．２７〜０．３１の範囲に形成され、 When the axial height b1 of the multiblade impeller is 1, the axial height (b1-b2) of the shroud is formed in the range of 0.27 to 0.31.

更に加えて、前記多翼羽根車の外径Ｄ２を１としたとき、シュラウドの入口端縁と、前記ベルマウス先端縁と重なり量Ｐが、０．００９〜０．０１１の範囲に形成される。 In addition, when the outer diameter D2 of the multi-blade impeller is set to 1, an overlapping amount P between the shroud inlet edge and the bell mouth tip edge is formed in the range of 0.009 to 0.011. .

本発明に成るターボファンは、最大風量の８０〜６０％の範囲において、騒音の低減を実現することが出来る。 The turbofan according to the present invention can realize noise reduction in the range of 80 to 60% of the maximum air volume.

本発明に成る例の、ケーシングに形成されたベルマウスと、多翼羽根車に形成されたシュラウドの対向の様子を示す断面略図である。It is a cross-sectional schematic diagram which shows the mode of the opposition of the bellmouth formed in the casing of the example which concerns on this invention, and the shroud formed in the multiblade impeller. 本発明に成るベルマウスとシュラウドとの位置関係と実現効果の例を示す説明図である。It is explanatory drawing which shows the example of the positional relationship of a bell mouth and shroud which concerns on this invention, and an implementation effect. 従来技術に成る例の、ベルマウスとシュラウドの対向の様子を示す断面略図である。It is a cross-sectional schematic diagram which shows the mode of the opposing of a bell mouth and a shroud of the example which becomes a prior art.

Explanation of symbols

１ケーシング
１−１ベルマウス
２多翼羽根車
２−１シュラウド
ｂ１羽根車の全高さ
ｂ２シュラウド出口の高さ
Ｄ１多翼羽根車のシュラウド入口端内径
Ｄ２多翼羽根車の外径
Ｐベルマウス先端縁とシュラウド入口端縁との重なり量
Ｓベルマウス先端縁外周面とシュラウド入口端内周面との隙間 DESCRIPTION OF SYMBOLS 1 Casing 1-1 Bellmouth 2 Multi-blade impeller 2-1 Shroud b1 Overall height b2 of shroud D1 Height of shroud outlet D1 Shroud inlet end inner diameter D2 of multi-blade impeller Outer diameter P of multi-blade impeller Bellmouth tip The amount of overlap S between the edge and the shroud inlet edge The clearance between the outer peripheral surface of the bell mouth tip edge and the inner peripheral surface of the shroud inlet end

Claims

A scroll casing having a suction opening that opens in the axial direction and a discharge opening that opens in the circumferential direction, and an annular inner peripheral surface that sequentially expands from the upstream side toward the downstream side, and an interior of the scroll casing In a turbofan having a rotatable multi-blade impeller disposed, a bell mouth tip formed at the inlet edge of the scroll casing is formed at the inlet edge of the shroud provided on the suction port side of the multi-blade impeller A turbofan characterized by being formed and arranged so as to overlap and be close to each other on the outer peripheral side of the edge.

The axial height (b1-b2) of the shroud is formed in the range of 0.27 to 0.31, where the axial height b1 of the multiblade impeller is 1. The turbofan according to claim 1.

3. The shroud inlet end inner diameter D 1 is formed in a range of 0.81 to 0.85, where the outer diameter D 2 of the multi-blade impeller is 1, 3. Turbo fan.

When the inner diameter D1 of the inlet end of the shroud is 1, the gap S between the inner peripheral surface of the shroud inlet end and the outer peripheral surface of the bell mouth tip edge formed in the scroll casing is in the range of 0.009 to 0.011. The turbofan according to claim 1, wherein the turbofan is formed.

When the outer diameter D2 of the multi-blade impeller is 1, the overlapping amount P between the shroud inlet edge and the bell mouth tip edge is formed in the range of 0.009 to 0.011. The turbofan according to any one of claims 1 to 4, wherein