JP4481414B2

JP4481414B2 - Fan seal structure

Info

Publication number: JP4481414B2
Application number: JP2000059406A
Authority: JP
Inventors: 行太島田; 孝一郎菊池
Original assignee: T.RAD CO., L T D.
Current assignee: T.RAD CO., L T D.
Priority date: 2000-03-03
Filing date: 2000-03-03
Publication date: 2010-06-16
Anticipated expiration: 2020-03-03
Also published as: JP2001248590A

Description

【０００１】
【発明の属する技術分野】
本発明は自動車用ラジエータ等に使用される軸流型または斜流型のファンのシール構造に関し、詳しくは翼先端を相互に連結するリングとその半径方向外側に配置されるシュラウドの筒状部間に逆流防止用のラビリンスシールを設けたものに関する。
【０００２】
【従来の技術】
従来から、自動車用ラジエータ等に使用されている軸流型または斜流型のファンは、エンジンやモータ等の駆動源により回転するボス部と、ボス部に放射状に突設された複数の翼を備え、翼の回転により軸方向に送風するものである。
自動車用ラジエータ等のファンには、その翼部外周にシュラウドの筒状部が被嵌され、翼部先端付近の逆流を可能な限り防止している。
【０００３】
一方、翼の強度を補強するため、その先端縁間をリングで相互に連結する方法が採用される。このような翼については、リングの遮蔽効果により逆流がある程度減少するのでシュラウドの筒状部は一般に省略される。
しかし上記いずれの逆流防止方法も近年の厳しい性能要求からは満足できるものとは言い難い。そこでさらに効果的な逆流防止の方法として、シュラウドの筒状部とリングの両者を組み合わせて使用し、それらの間にラビリンスシール効果を発揮する部分を形成したものが知られている。（例えば特公昭４０ー４９５３号公報、実開昭５３ー１２８９０６号公報等）
【０００４】
一般にラビリンスシールは回転機器の軸受部のシールを目的として使用され、回転側である軸と固定側である軸受部の間に絞り片と空間部を交互に設けて構成される。そしてシール部の流れは絞り片によって形成される絞り口を通過する際に等エントロピー膨張し、そこで減速し膨張室（空間部）内で等圧のもとで静温度に回復し、さらに次の絞り口に流入するという工程を繰り返すことによりシール効果を奏するものである。
前記公報に記載された方法は回転側をリング、固定側をシュラウドの筒状部とし、シュラウドの筒状部の内周面に設けた凹部に翼の外周部を連結するリングを受け入れ、その凹部にシール部を形成している。
【０００５】
【発明が解決しようとする課題】
しかし、このようにシュラウドの筒状部の凹部にリングを挿入した構造では、シュラウドの筒状部に軸方向からファンを挿入して組み立てることが難かしい。それを解決するには例えばシュラウドの筒状部を分割型とし、各分割部分をファンの外側から組み付ける必要があり、それだけ構造が複雑となりコストアップになるという別の問題が発生する。そこで本発明はこのような問題を解決した新しいファンのシール構造を提供することを課題とするものである。
【０００６】
【課題を解決するための手段】
すなわち請求項１に記載の発明は、ボス部２ａに複数の翼３を放射状に設けた軸流型または斜流型のファン１のシール構造において、
各翼３の先端縁間を互に連結する円形のリング４と、
そのリング４の半径方向外側に間隙を有して被嵌されたシュラウド６の筒状部５と、
そのリング４の外周に環状に突設された第１絞り片Ｓと、
その第１絞り片Ｓに隣接して前記シュラウド６の筒状部５の内周面に環状に突設され、その第１絞り片Ｓの先端外直径よりも小さい先端内直径を有する第１逆絞り片Ｒと、
を有し、
その第１絞り片Ｓに対して、第１逆絞り片Ｒの反対側では、リング４およびシュラウド６の筒状部５に突設される他の絞り片および逆絞り片の夫々の先端直径は、夫々の絞り片と逆絞り片とが干渉することなく、そのリング４がシュラウド６の筒状部５に軸線方向から挿入できる大きさに決定され、
且つ、それら絞り片と逆絞り片と筒状部５並びにリング４によりラビリンスシール部８が形成されたことを特徴とするファンのシール構造である。
【０００７】
請求項２に記載の発明は、ボス部２ａに複数の翼３を放射状に設けた軸流型または斜流型のファン１のシール構造において、
各翼３の先端縁間を互に連結する円形のリング４と、
そのリング４の半径方向外側に間隙を有して被嵌されたシュラウド６の筒状部５と、
そのリング４の外周に環状に突設された第１絞り片Ｓと、
その第１絞り片Ｓに隣接して前記シュラウド６の筒状部５の内周面に環状に突設され、その第１絞り片Ｓの先端外直径よりも小さい先端内直径を有する第１逆絞り片Ｒと、
を有し、
その第１逆絞り片Ｒに対して、第１絞り片Ｓの反対側では、リング４およびシュラウド６の筒状部５に突設される他の絞り片および逆絞り片の夫々の先端直径が、夫々の絞り片と逆絞り片とが干渉することなく、そのリング４がシュラウド６の筒状部５に軸線方向から挿入できる大きさに決定され、
且つ、それら絞り片と逆絞り片と筒状部５並びにリング４によりラビリンスシール部８が形成されたことを特徴とするファンのシール構造である。
【０００８】
請求項３に記載の発明は、請求項１または請求項２において、
リング４の軸方向の少なくとも一端部が、端に向かってその直径が次第に大きくなるベルマウス状に形成されたファンのシール構造である。
請求項４に記載の発明は、請求項１または請求項２において、
ラビリンスシール部８は、リング４側の軸方向両端部または該両端部と中間部に設けた絞り片と、夫々の絞り片の間に位置し、シュラウド６の筒状部５側の内面に突設された逆絞り片とで形成された食い違い型であるファンのシール構造である。
【０００９】
【発明の実施の形態】
次に、本発明の実施の形態を図面により説明する。
図１（ａ）は本発明のシール構造を自動車用ラジエータ等の熱交換器の冷却ファンに適用した例で、その縦断面図であり（ｂ）はその要部拡大図である。また図２は図１のII−II矢視図である。
【００１０】
軸流型または斜流型のファン１は図示しないエンジンのクランク軸により回転される駆動軸２と、その駆動軸２が連結されるボス部２ａと、そのボス部２ａに放射状に取り付けられた複数の翼３を有している。各翼３の先端縁間は相互にリング４により一体に連結され、リング４の半径方向外側には所定の間隙をもってシュラウド６の筒状部５が配置される。リング４には、半径方向に環状の仕切り片からなる第１絞り片Ｓ〜第４絞り片Ｓ４が所定間隔で複数設けられている。
この例は、リング４の幅方向両端部に空気流の乱れや渦の発生を防止するためにベルマウスＭが設けられたものであり、それらベルマウスＭが両端部の第１絞り片Ｓ，第４絞り片Ｓ４を兼用している。このベルマウスＭは、その端部側に向かって直径が次第に拡開するように形成されている。
【００１１】
次に筒状部５は、浅い漏斗状のシュラウド６の一端の中心部に一体に延在され、その他端開口がラジエータ等の熱交換器７の周縁に接続されている。なお、筒状部５とシュラウド６とは両者を別体に形成し、それらを締結または接着剤で一体化してもよい。筒状部５の内周面には、第１逆絞り片Ｒ〜第３逆絞り片Ｒ３が環状に突設形成されている。そして、第１逆絞り片Ｒは図において、第１絞り片Ｓの左側に隣接して配置され、その先端内直径が第１絞り片Ｓの先端外直径よりも小さく形成され、それにより第１逆絞り片Ｒと第１絞り片Ｓは、軸方向の投影がその先端部で重なるように形成されている。そして、両先端部間には僅かな隙間が軸方向に形成されている。なお、第２絞り片Ｓ２〜第４絞り片Ｓ４の先端部外直径は、第１絞り片Ｓのそれと同一である。
【００１２】
次に、第２逆絞り片Ｒ２は第２絞り片Ｓ２と第３絞り片Ｓ３との中間に突設され、その先端内直径は第１絞り片Ｓ〜第４絞り片Ｓ４の先端外直径よりも大に形成され、それらの軸方向への投影は重ならない。更に、第３逆絞り片Ｒ３は第４絞り片Ｓ４の外側に配置され、その先端内直径は第１絞り片Ｓ〜第４絞り片Ｓ４の先端外直径よりも大に形成されている。
そのため、このようにしてなるファン１をシュラウド６の筒状部５に収納する際、夫々の絞り片および逆絞り片が互いに干渉することなく図の状態に収納することができる。例えば、ファン１をシュラウド内に右方から左方に移動して図の状態に収納できる。そして、この第１逆絞り片Ｒ〜第３逆絞り片Ｒ３を含む筒状部５と第１絞り片Ｓ〜第４絞り片Ｓ４を含むリング４とでいわゆる、食い違い型のラビリンスシール部８が形成される。
【００１３】
このようなラビリンスシール部８においては、リング４の各絞り片と、筒状部５の各逆絞り片により複数の絞り口が形成され、翼３の下流側からの逆流ｆが各絞り口および逆絞り口を通過する度に、等エントロピ膨張し、減速した逆流ｆは近接する各縁の中間にある空間部（膨張室）において、等圧で静温度に回復するという作業を繰り返すことにより、ラビリンスシール効果を有効に発揮させている。
更に、第１絞り片Ｓの先端部における軸方向への投影は、第１逆絞り片Ｒの先端部に重なるため、それらの間におけるシール効果は特に高い。なぜならば、軸方向に流通する逆流ｆが第１逆絞り片Ｒと第１絞り片Ｓとの間を通過する流通抵抗が高くなるからである。
このようなラビリンスシール効果の高い構造にも係わらず、ファン１をシュラウド６の筒状部５に軸方向から容易に挿入して組立てることが可能である。
【００１４】
次に図３は、図１の変形例を示す部分断面図であり、この例では第１逆絞り片Ｒが第１絞り片Ｓの内側に配置され、且つ第１逆絞り片Ｒの先端部を軸方向に投影すると、第１絞り片Ｓに重なり合うものである。そして、第１逆絞り片Ｒに対し第１絞り片Ｓの反対側に位置する第２逆絞り片Ｒ２，第３逆絞り片Ｒ３の先端内直径が第３絞り片Ｓ３，第４絞り片Ｓ４の先端外直径よりも大きく形成されている。それと共に、第２絞り片Ｓ２の先端外直径よりも第１逆絞り片Ｒの先端外直径の方が大きく形成されている。そのため、リング４は図３において、左方から右方に軸方向に移動して、同図の状態に組立てることができる。この実施の形態は、請求項２に相当する発明内容を具現したものである。
【００１５】
次に図４は、本発明の第３の実施の形態を示す要部縦断面図であり、この例はリング４の幅方向両縁部に形成された第１絞り片Ｓ，第２絞り片Ｓ２が夫々ベルマウスＭを構成する。そして、第１絞り片Ｓの軸方向の投影が第１逆絞り片Ｒの先端部に重なり合うものであり、第２絞り片Ｓ２の先端部外直径よりも第２逆絞り片Ｒ２の先端部外直径の方が大に形成され、且つ第２逆絞り片Ｒ２の外側に第２絞り片Ｓ２が配置されたものである。
次に図５は、本発明の第４の実施の形態を示し、この例が図４のそれと異なる点は、第２絞り片Ｓ２が第２逆絞り片Ｒ２の内側に位置された点のみにある。
【００１６】
次に図６は、本発明の第５の実施の形態を示し、この例は第１逆絞り片Ｒの先端部が第１絞り片Ｓ側に断面Ｌ字状に曲折され、第１絞り片Ｓの先端部が第１逆絞り片Ｒ側に断面逆Ｌ字状に形成され、それらにより逆流ｆの流通をより困難にし、シール効果を高くしたものである。
この例でも、前記各実施の形態と同様に、第１絞り片Ｓの軸方向の投影が第１逆絞り片Ｒに重なるものである。そして、第１逆絞り片Ｓの先端部外直径は第２逆絞り片Ｒ２の先端部内直径よりも小に形成され、リング４を筒状部５に右方から左方に挿入して組立てることができるものである。また、第２絞り片Ｓ２は第２逆絞り片Ｒ２の外側に位置し、第２絞り片Ｓ２の先端外直径は、第２逆絞り片Ｒ２の先端内直径よりも大に形成されている。それにより、シール効果がさらに高くなる。
【００１７】
次に図７は、本発明の第６の実施の形態であり、第１絞り片Ｓ，第２絞り片Ｓ２が第１逆絞り片Ｒ，第２逆絞り片Ｒ２の内部に位置すると共に、第３絞り片Ｓ３が第２逆絞り片Ｒ２の外側に位置するものである。そして、第１絞り片Ｓ〜第３絞り片Ｓ３の先端部外直径がほぼ等しく、且つその外直径は第２逆絞り片Ｒ２の先端部内直径よりも小に形成されている。
次に図８は、本発明の第７の実施の形態を示し、この例では第３逆絞り片Ｒ３の断面が斜め外側に形成されている。なお、この斜め外側の代わりに斜め内側に形成してもよい。或いは筒状部５の先端に断面円形状の膨出部を設けてもよい。
次に図９は、本発明の第８の実施の形態であり、この例は筒状部５の先端部が平坦に形成されたものである。
そして、図４〜図９のいずれの例もリング４を図において右方から左方に挿入して組立てることができると共に、第１絞り片Ｓを軸方向に投影したとき、その投影と第１逆絞り片Ｒとが重なるものである。
【００１８】
【発明の効果】
以上のように本発明のファンのシール構造によれば、リングとシュラウドの筒状部との間に有効なラビリンスシール部が形成されると共に、リングで連結された各翼をシュラウドの筒状部内に軸方向から容易に挿入することができる。しかも、少なくとも、第１逆絞り片Ｒの先端部と第１絞り片Ｓの先端部とが軸方向の投影において重なるように形成され、そこにおけるシール効果がより大きくなるものである。
【図面の簡単な説明】
【図１】本発明のシール構造を自動車用熱交換器の冷却ファンに適応した例で、その縦断面図およびその要部拡大図。
【図２】図１のII−II矢視図。
【図３】本発明の第２の実施の形態を示す要部縦断面図。
【図４】本発明の第３の実施の形態を示す要部縦断面図。
【図５】本発明の第４の実施の形態を示す要部縦断面図。
【図６】本発明の第５の実施の形態を示す要部縦断面図。
【図７】本発明の第６の実施の形態を示す要部縦断面図。
【図８】本発明の第７の実施の形態を示す要部縦断面図。
【図９】本発明の第８の実施の形態を示す要部縦断面図。
【符号の説明】
１ファン
２駆動軸
２ａボス部
３翼
４リング
５筒状部
６シュラウド
７熱交換器
８ラビリンスシール部
Ｓ第１絞り片
Ｓ２第２絞り片
Ｓ３第３絞り片
Ｓ４第４絞り片
Ｒ第１逆絞り片
Ｒ２第２逆絞り片
Ｒ３第３逆絞り片
Ｍベルマウス
ｆ逆流
ｗ主流[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a seal structure of an axial flow type or mixed flow type fan used in a radiator for an automobile, and more particularly, between a ring connecting blade tips to each other and a cylindrical portion of a shroud disposed radially outside thereof. It is related with what provided the labyrinth seal for backflow prevention.
[0002]
[Prior art]
Conventionally, an axial flow type or mixed flow type fan used in an automotive radiator or the like has a boss portion that is rotated by a driving source such as an engine or a motor, and a plurality of blades that are radially projected on the boss portion. It is provided and blows in the axial direction by rotation of the blade.
A fan such as a radiator for an automobile has a shroud cylindrical portion fitted on the outer periphery of the wing to prevent backflow near the tip of the wing as much as possible.
[0003]
On the other hand, in order to reinforce the strength of the blade, a method of connecting the tip edges to each other with a ring is adopted. For such wings, the shroud tube is generally omitted because the backflow is reduced to some extent by the shielding effect of the ring.
However, none of the above-described backflow prevention methods can be said to be satisfactory from recent severe performance requirements. Therefore, as a more effective backflow prevention method, a combination of both the cylindrical portion of the shroud and the ring and a portion that exhibits a labyrinth seal effect between them is known. (For example, Japanese Patent Publication No. 40-4953, Japanese Utility Model Publication No. 53-128906, etc.)
[0004]
Generally, the labyrinth seal is used for the purpose of sealing a bearing portion of a rotating device, and is configured by alternately providing a throttle piece and a space portion between a shaft on the rotating side and a bearing portion on the fixed side. The flow of the seal part isentropically expanded when passing through the throttle port formed by the throttle piece, decelerates there, and recovers to a static temperature under an equal pressure in the expansion chamber (space part). A sealing effect is achieved by repeating the process of flowing into the throttle port.
The method described in the above publication accepts a ring that connects the outer peripheral part of the wing to a concave part provided on the inner peripheral surface of the cylindrical part of the shroud, with the rotating side as a ring and the stationary side as a cylindrical part of the shroud, and the concave part A seal portion is formed.
[0005]
[Problems to be solved by the invention]
However, in such a structure in which the ring is inserted into the concave portion of the cylindrical portion of the shroud, it is difficult to assemble the fan by inserting the fan into the cylindrical portion of the shroud from the axial direction. In order to solve this problem, for example, the cylindrical portion of the shroud needs to be divided, and each divided portion needs to be assembled from the outside of the fan, resulting in another problem that the structure becomes complicated and the cost is increased. Therefore, an object of the present invention is to provide a new fan seal structure that solves such problems.
[0006]
[Means for Solving the Problems]
That is, the invention according to claim 1 is a seal structure of an axial flow type or mixed flow type fan 1 in which a plurality of blades 3 are provided radially on a boss portion 2a.
A circular ring 4 connecting the tip edges of each wing 3 to each other;
A cylindrical portion 5 of the shroud 6 fitted with a gap on the radially outer side of the ring 4;
A first throttle piece S projecting annularly on the outer periphery of the ring 4;
Adjacent to the first throttle piece S, a first reverse having a tip inner diameter smaller than the outer diameter of the tip of the first throttle piece S is provided on the inner peripheral surface of the cylindrical portion 5 of the shroud 6 in an annular shape. A diaphragm piece R;
Have
On the opposite side of the first reverse throttle piece R with respect to the first throttle piece S, the tip diameters of the other throttle pieces and the reverse throttle pieces protruding from the ring 4 and the cylindrical portion 5 of the shroud 6 are as follows. The size of the ring 4 is determined so that the ring 4 can be inserted into the cylindrical portion 5 of the shroud 6 from the axial direction without the interference between the respective diaphragm pieces and the reverse diaphragm pieces.
The fan seal structure is characterized in that a labyrinth seal portion 8 is formed by the throttle piece, the reverse throttle piece, the tubular portion 5 and the ring 4.
[0007]
The invention according to claim 2 is the seal structure of the axial flow or mixed flow type fan 1 in which a plurality of blades 3 are provided radially on the boss portion 2a.
A circular ring 4 connecting the tip edges of each wing 3 to each other;
A cylindrical portion 5 of the shroud 6 fitted with a gap on the radially outer side of the ring 4;
A first throttle piece S projecting annularly on the outer periphery of the ring 4;
Adjacent to the first throttle piece S, a first reverse having a tip inner diameter smaller than the outer diameter of the tip of the first throttle piece S is provided on the inner peripheral surface of the cylindrical portion 5 of the shroud 6 in an annular shape. A diaphragm piece R;
Have
With respect to the first reverse throttle piece R, on the opposite side of the first throttle piece S, the tip diameters of the other throttle pieces and the reverse throttle pieces protruding from the ring 4 and the cylindrical portion 5 of the shroud 6 are set. The size of the ring 4 is determined so that the ring 4 can be inserted into the cylindrical portion 5 of the shroud 6 from the axial direction without the interference between the respective diaphragm pieces and the reverse diaphragm pieces.
The fan seal structure is characterized in that a labyrinth seal portion 8 is formed by the throttle piece, the reverse throttle piece, the tubular portion 5 and the ring 4.
[0008]
The invention according to claim 3 is the invention according to claim 1 or 2,
At least one end in the axial direction of the ring 4 is a fan sealing structure formed in a bell mouth shape whose diameter gradually increases toward the end.
The invention according to claim 4 is the invention according to claim 1 or claim 2,
The labyrinth seal portion 8 is positioned between both the axial end portions on the ring 4 side or the throttle pieces provided at the both end portions and the intermediate portion, and between the respective throttle pieces, and protrudes from the inner surface of the shroud 6 on the cylindrical portion 5 side. This is a seal structure of a staggered fan formed by a reverse throttle piece provided.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1A is an example in which the sealing structure of the present invention is applied to a cooling fan of a heat exchanger such as a radiator for an automobile, and FIG. 1B is a longitudinal sectional view thereof, and FIG. 2 is a view taken in the direction of arrows II-II in FIG.
[0010]
The axial flow type or mixed flow type fan 1 includes a drive shaft 2 that is rotated by a crankshaft of an engine (not shown), a boss portion 2a to which the drive shaft 2 is coupled, and a plurality of radially attached to the boss portion 2a. The wing 3 is provided. The tip edges of the blades 3 are integrally connected to each other by a ring 4, and the cylindrical portion 5 of the shroud 6 is disposed on the radially outer side of the ring 4 with a predetermined gap. The ring 4 is provided with a plurality of first to fourth throttle pieces S4 to S4 made of annular partition pieces in the radial direction at predetermined intervals.
In this example, bell mouths M are provided at both ends in the width direction of the ring 4 in order to prevent air flow turbulence and vortex generation, and these bell mouths M are connected to the first throttle pieces S, The fourth aperture piece S4 is also used. The bell mouth M is formed so that its diameter gradually expands toward the end side.
[0011]
Next, the cylindrical part 5 is integrally extended to the center part of one end of the shallow funnel-shaped shroud 6, and the other end opening is connected to the peripheral edge of the heat exchanger 7 such as a radiator. In addition, the cylindrical part 5 and the shroud 6 may be formed separately from each other, and may be integrated by fastening or an adhesive. On the inner peripheral surface of the cylindrical portion 5, a first reverse throttle piece R to a third reverse throttle piece R3 are formed to project in an annular shape. The first reverse throttle piece R is disposed adjacent to the left side of the first throttle piece S in the drawing, and the inner diameter of the tip is formed smaller than the outer diameter of the tip of the first throttle piece S, whereby the first The reverse aperture piece R and the first aperture piece S are formed so that the axial projections overlap at the tip. A slight gap is formed in the axial direction between the two end portions. It should be noted that the outer diameters of the tips of the second diaphragm pieces S2 to S4 are the same as those of the first diaphragm pieces S.
[0012]
Next, the second reverse diaphragm piece R2 is provided in the middle between the second diaphragm piece S2 and the third diaphragm piece S3, and the inner diameter of the tip is larger than the outer diameters of the first diaphragm piece S to the fourth diaphragm piece S4. And their axial projections do not overlap. Further, the third reverse throttle piece R3 is disposed outside the fourth throttle piece S4, and the inner diameter of the tip is formed larger than the outer diameters of the first throttle piece S to the fourth throttle piece S4.
Therefore, when the fan 1 constructed as described above is housed in the cylindrical portion 5 of the shroud 6, the respective diaphragm pieces and the reverse diaphragm pieces can be housed in the state shown in the figure without interfering with each other. For example, the fan 1 can be moved from right to left in the shroud and stored in the state shown in the figure. A so-called staggered labyrinth seal portion 8 is formed by the cylindrical portion 5 including the first reverse throttle piece R to the third reverse throttle piece R3 and the ring 4 including the first throttle piece S to the fourth throttle piece S4. It is formed.
[0013]
In such a labyrinth seal portion 8, a plurality of throttle openings are formed by each throttle piece of the ring 4 and each reverse throttle piece of the tubular portion 5, and a reverse flow f from the downstream side of the blade 3 By repeating the work of isentropic expansion and decelerating backflow f every time it passes through the reverse throttle opening, the space portion (expansion chamber) in the middle of each adjacent edge is restored to a static temperature with equal pressure, The labyrinth seal effect is effectively demonstrated.
Furthermore, since the projection in the axial direction at the tip of the first throttle piece S overlaps the tip of the first reverse throttle piece R, the sealing effect between them is particularly high. This is because the flow resistance in which the backflow f flowing in the axial direction passes between the first reverse throttle piece R and the first throttle piece S becomes high.
Despite such a structure having a high labyrinth sealing effect, the fan 1 can be easily inserted into the cylindrical portion 5 of the shroud 6 from the axial direction and assembled.
[0014]
Next, FIG. 3 is a partial cross-sectional view showing a modification of FIG. 1. In this example, the first reverse throttle piece R is disposed inside the first throttle piece S, and the front end of the first reverse throttle piece R is shown. Is overlapped with the first diaphragm piece S when projected in the axial direction. The inner diameters of the tips of the second reverse throttle piece R2 and the third reverse throttle piece R3 located on the opposite side of the first throttle piece S with respect to the first reverse throttle piece R are the third throttle piece S3 and the fourth throttle piece S4. It is formed larger than the outer diameter of the tip. At the same time, the tip outer diameter of the first reverse throttle piece R is formed larger than the tip outer diameter of the second throttle piece S2. Therefore, the ring 4 can be assembled in the state shown in FIG. 3 by moving in the axial direction from left to right in FIG. This embodiment embodies the content of the invention corresponding to claim 2.
[0015]
Next, FIG. 4 is a longitudinal sectional view showing a main part of a third embodiment of the present invention. This example shows a first throttle piece S and a second throttle piece formed at both edges in the width direction of the ring 4. S2 constitutes the bell mouth M, respectively. The projection in the axial direction of the first diaphragm piece S overlaps the tip part of the first reverse diaphragm piece R, and the outer diameter of the tip part of the second reverse diaphragm piece R2 is larger than the outer diameter of the tip part of the second diaphragm piece S2. The diameter is larger, and the second diaphragm piece S2 is arranged outside the second reverse diaphragm piece R2.
Next, FIG. 5 shows a fourth embodiment of the present invention. This example is different from that of FIG. 4 only in that the second diaphragm piece S2 is positioned inside the second reverse diaphragm piece R2. is there.
[0016]
Next, FIG. 6 shows a fifth embodiment of the present invention. In this example, the tip of the first reverse throttle piece R is bent in a L-shaped cross section on the first throttle piece S side. The tip of S is formed in an inverted L-shaped cross section on the first reverse throttle piece R side, thereby making the flow of the reverse flow f more difficult and enhancing the sealing effect.
Also in this example, the projection in the axial direction of the first diaphragm piece S overlaps the first reverse diaphragm piece R as in the above-described embodiments. The outer diameter of the tip of the first reverse throttle piece S is formed smaller than the inner diameter of the tip of the second reverse throttle piece R2, and the ring 4 is inserted into the cylindrical part 5 from right to left and assembled. It is something that can be done. The second diaphragm piece S2 is located outside the second reverse diaphragm piece R2, and the outer diameter of the distal end of the second diaphragm piece S2 is formed larger than the inner diameter of the distal end of the second reverse diaphragm piece R2. Thereby, the sealing effect is further enhanced.
[0017]
Next, FIG. 7 shows a sixth embodiment of the present invention, in which the first diaphragm piece S and the second diaphragm piece S2 are located inside the first reverse diaphragm piece R and the second reverse diaphragm piece R2, The third diaphragm piece S3 is located outside the second reverse diaphragm piece R2. The outer diameters of the distal end portions of the first throttle piece S to the third throttle piece S3 are substantially equal, and the outer diameters are smaller than the inner diameter of the distal end portion of the second reverse throttle piece R2.
Next, FIG. 8 shows a seventh embodiment of the present invention. In this example, the cross section of the third reverse diaphragm piece R3 is formed obliquely outside. In addition, you may form diagonally inside instead of this diagonally outer side. Alternatively, a bulging portion having a circular cross section may be provided at the tip of the cylindrical portion 5.
Next, FIG. 9 shows an eighth embodiment of the present invention. In this example, the tip of the cylindrical portion 5 is formed flat.
4 to 9 can be assembled by inserting the ring 4 from the right to the left in the drawing, and when the first aperture piece S is projected in the axial direction, the projection and the first The reverse aperture piece R overlaps.
[0018]
【The invention's effect】
As described above, according to the fan seal structure of the present invention, an effective labyrinth seal portion is formed between the ring and the cylindrical portion of the shroud, and each blade connected by the ring is placed in the cylindrical portion of the shroud. Can be easily inserted from the axial direction. Moreover, at least the tip of the first reverse throttle piece R and the tip of the first throttle piece S are formed so as to overlap in the axial projection, and the sealing effect there is greater.
[Brief description of the drawings]
FIG. 1 is an example in which the seal structure of the present invention is applied to a cooling fan of an automotive heat exchanger, and a longitudinal sectional view and an enlarged view of a main part thereof.
FIG. 2 is a view taken along the line II-II in FIG.
FIG. 3 is a longitudinal sectional view of an essential part showing a second embodiment of the present invention.
FIG. 4 is a longitudinal sectional view of an essential part showing a third embodiment of the present invention.
FIG. 5 is a longitudinal sectional view showing a main part of a fourth embodiment of the present invention.
FIG. 6 is a longitudinal sectional view showing a main part of a fifth embodiment of the present invention.
FIG. 7 is a longitudinal sectional view showing an essential part of a sixth embodiment of the present invention.
FIG. 8 is a longitudinal sectional view of an essential part showing a seventh embodiment of the present invention.
FIG. 9 is a longitudinal sectional view showing a main part of an eighth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fan 2 Drive shaft 2a Boss part 3 Wing | blade 4 Ring 5 Cylindrical part 6 Shroud 7 Heat exchanger 8 Labyrinth seal part S 1st aperture piece S2 2nd aperture piece S3 3rd aperture piece S4 4th aperture piece R 1st reverse Restriction piece R2 Second reverse restriction piece R3 Third reverse restriction piece M Bellmouth f Reverse flow w Mainstream

Claims

In the seal structure of the axial flow or mixed flow type fan 1 in which a plurality of blades 3 are provided radially on the boss portion 2a,
A circular ring 4 connecting the tip edges of each wing 3 to each other;
A cylindrical portion 5 of the shroud 6 fitted with a gap on the radially outer side of the ring 4;
A first throttle piece S projecting annularly on the outer periphery of the ring 4;
Adjacent to the first throttle piece S, a first reverse having a tip inner diameter smaller than the outer diameter of the tip of the first throttle piece S is provided on the inner peripheral surface of the cylindrical portion 5 of the shroud 6 in an annular shape. A diaphragm piece R;
Have
On the opposite side of the first reverse throttle piece R with respect to the first throttle piece S, the tip diameters of the other throttle pieces and the reverse throttle pieces protruding from the ring 4 and the cylindrical portion 5 of the shroud 6 are as follows. The size of the ring 4 is determined so that the ring 4 can be inserted into the cylindrical portion 5 of the shroud 6 from the axial direction without the interference between the respective diaphragm pieces and the reverse diaphragm pieces.
The fan seal structure is characterized in that a labyrinth seal portion 8 is formed by the throttle piece, the reverse throttle piece, the cylindrical portion 5 and the ring 4.

In the seal structure of the axial flow or mixed flow type fan 1 in which a plurality of blades 3 are provided radially on the boss portion 2a,
A circular ring 4 connecting the tip edges of each wing 3 to each other;
A cylindrical portion 5 of the shroud 6 fitted with a gap on the radially outer side of the ring 4;
A first throttle piece S projecting annularly on the outer periphery of the ring 4;
Adjacent to the first throttle piece S, a first reverse having a tip inner diameter smaller than the outer diameter of the tip of the first throttle piece S is provided on the inner peripheral surface of the cylindrical portion 5 of the shroud 6 in an annular shape. A diaphragm piece R;
Have
On the opposite side of the first throttle piece S with respect to the first reverse throttle piece R, the respective tip diameters of the other throttle pieces and the reverse throttle piece protruding from the cylindrical portion 5 of the ring 4 and the shroud 6 are as follows. The size of the ring 4 is determined such that the ring 4 can be inserted into the cylindrical portion 5 of the shroud 6 from the axial direction without interference between the respective diaphragm pieces and the reverse diaphragm pieces.
The fan seal structure is characterized in that the labyrinth seal portion 8 is formed by the throttle piece, the reverse throttle piece, the cylindrical portion, and the ring.

In claim 1 or claim 2,
A fan sealing structure in which at least one end portion in the axial direction of the ring 4 is formed in a bell mouth shape whose diameter gradually increases toward the end.

In claim 1 or claim 2,
The labyrinth seal portion 8 is positioned between both the axial end portions on the ring 4 side or the throttle pieces provided at the both end portions and the intermediate portion, and between the respective throttle pieces, and protrudes from the inner surface of the shroud on the cylindrical portion 5 side. The seal structure of the fan which is a discrepancy type formed by the reverse throttle piece.