JP2006112512A - Shaft sealing mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shaft sealing mechanism having a plurality of stages of leaf seals and capable of suppressing the length of a rotational shaft. <P>SOLUTION: In a stator 60, a first stage leaf seal 120 and a second stage leaf seal 220 are placed in sequence from a high-pressure side region to a low-pressure side region along the axial direction of the rotational shaft 4. A mounting groove 81 along the circumferential direction is formed on the inner peripheral face of the stator 60, and a shared mounting piece 182 is provided between the leaf seals 120, 220 adjacent to each other. The leaf seals 120, 220 and the mounting piece 182 are integrally fitted into the mounting groove 81 of the stator 6 along the circumferential direction and fixed to the stator 60 by a bolt 183. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、ガスタービン、蒸気タービン、圧縮機、水車、冷凍機、ポンプ等の大型流体機械の回転軸に対しての軸シール機構に関し、特に、回転軸の周面とこの回転軸に同軸状で静止した静止部材の内周面との隙間においての高圧側から低圧側への作動流体の漏れを抑える軸シール機構に関する。   The present invention relates to a shaft seal mechanism for a rotating shaft of a large fluid machine such as a gas turbine, a steam turbine, a compressor, a water turbine, a refrigerator, a pump, and the like, and in particular, is coaxial with the peripheral surface of the rotating shaft and the rotating shaft. The present invention relates to a shaft seal mechanism that suppresses leakage of working fluid from a high pressure side to a low pressure side in a gap with an inner peripheral surface of a stationary member that is stationary.

一般に、ガスタービンや蒸気タービン等の大型流体機械においては、圧縮空気や燃焼ガスや蒸気等の作動流体（以下、単に「ガス」と記すことがある）を本質的に流動させる主流路以外に、回転軸の周面とこの回転軸に同軸状で静止した静止部材（例えば静翼の内周端を保持する環状部材）の内周面との間に環状の隙間が形成されるのは避けられない。その隙間に対して何ら工夫を施さなければ、その隙間を通じてガスが高圧側から低圧側へ向けて不用意に漏れ、結果として流体機械の効率が低下してしまう。従って、その隙間を通じたガスの漏れを最小限に抑えることは極めて重要であり、これを実現すべく、その隙間に軸シール機構が適用される。   In general, in a large fluid machine such as a gas turbine or a steam turbine, in addition to a main flow channel that essentially flows a working fluid such as compressed air, combustion gas, or steam (hereinafter sometimes simply referred to as “gas”), It is unavoidable that an annular gap is formed between the peripheral surface of the rotating shaft and the inner peripheral surface of a stationary member that is coaxial and stationary on the rotating shaft (for example, an annular member that holds the inner peripheral end of the stationary blade). Absent. If no measures are taken with respect to the gap, gas leaks inadvertently from the high-pressure side to the low-pressure side through the gap, resulting in a decrease in the efficiency of the fluid machine. Therefore, it is extremely important to minimize gas leakage through the gap, and in order to realize this, a shaft seal mechanism is applied to the gap.

軸シール機構としては、従来一般には、静止部材の内周面から複数のフィンが突出して成る非接触型のいわゆるラビリンスシールが幅広く用いられる。しかし、ラビリンスシールでは、回転過渡期の軸振動や熱過渡的な熱変形時にもフィン先端が回転軸の周面に接触しないように構成する必要があるため、回転軸の周面とフィン先端との隙間をある程度確保しなければならず、その結果、ガスの漏れを大きく抑えることができないという問題がある。   As the shaft seal mechanism, a non-contact type so-called labyrinth seal in which a plurality of fins protrude from the inner peripheral surface of a stationary member has been widely used. However, the labyrinth seal must be configured so that the tip of the fin does not come into contact with the peripheral surface of the rotating shaft even during axial vibration or thermal transient thermal deformation during the rotational transition period. As a result, there is a problem that gas leakage cannot be greatly suppressed.

一方近年では、ガスの漏れ量を格段に低減できる軸シール機構として、回転軸の軸方向に一定幅を有する平板状の薄板を回転軸の周方向に多重に配置した構造となるいわゆるリーフシールがある（例えば特許文献１参照）。以下、このリーフシールの詳細構成について、図８〜図１５を参照しながら説明していく。なお、ここではリーフシールが適用される大型流体機械として、その代表格であるガスタービンを一例に挙げて説明する。   On the other hand, in recent years, as a shaft seal mechanism that can significantly reduce the amount of gas leakage, a so-called leaf seal having a structure in which flat thin plates having a certain width in the axial direction of the rotating shaft are arranged in the circumferential direction of the rotating shaft is provided. Yes (see, for example, Patent Document 1). Hereinafter, the detailed structure of the leaf seal will be described with reference to FIGS. Here, as a large-sized fluid machine to which a leaf seal is applied, a typical gas turbine will be described as an example.

図８に示すガスタービンＧｔは、多量の空気を内部に取り込んで圧縮する圧縮機１と、圧縮機１にて圧縮された空気に燃料を混合して燃焼させる燃焼器２と、燃焼器２で発生した高温高圧の燃焼ガスが内部に導入されこの燃焼ガスの熱エネルギーを回転エネルギーに変換するタービン３と、タービン３の回転エネルギーを直接受けてその一部を圧縮機１の動力として伝達する回転軸４と、を有している。   A gas turbine Gt shown in FIG. 8 includes a compressor 1 that takes in a large amount of air and compresses it, a combustor 2 that mixes and burns fuel into the air compressed by the compressor 1, and a combustor 2. The generated high-temperature and high-pressure combustion gas is introduced into the turbine 3 that converts the thermal energy of the combustion gas into rotational energy, and the rotation that directly receives the rotational energy of the turbine 3 and transmits a part of it as power for the compressor 1. And a shaft 4.

タービン３では、回転軸４に軸方向で複数段設けられた複数の動翼１０が、吹き付けられた燃焼ガスの圧力を受けることで回転軸４と共に回転する。こうして、燃焼ガスの熱エネルギーを回転軸４の回転という機械的な回転エネルギーに変換して動力が発生する。回転軸４に与えられた回転エネルギーは軸端から取り出されて発電に利用される。また、タービン３には、回転軸４側の動翼１０の他に、タービン３のケーシング９側に複数の静翼１１が設けられていて、これら動翼１０と静翼１１とが、回転軸４の軸方向に交互に配置される。そして、回転軸４と静翼１１（実際には、静翼１１の内周端を保持する環状の静止部材）との間には、その隙間を通じて高圧側から低圧側へ漏れる燃焼ガスの漏れ量を低減するための軸シール機構として、リーフシール２０が設けられる。   In the turbine 3, a plurality of rotor blades 10 provided in a plurality of stages in the axial direction on the rotating shaft 4 rotate together with the rotating shaft 4 by receiving the pressure of the sprayed combustion gas. Thus, power is generated by converting the thermal energy of the combustion gas into mechanical rotational energy called rotation of the rotating shaft 4. The rotational energy given to the rotating shaft 4 is taken out from the shaft end and used for power generation. In addition to the moving blade 10 on the rotating shaft 4 side, the turbine 3 is provided with a plurality of stationary blades 11 on the casing 9 side of the turbine 3. The moving blade 10 and the stationary blade 11 are connected to the rotating shaft. 4 are arranged alternately in the axial direction. The amount of combustion gas that leaks from the high pressure side to the low pressure side through the gap between the rotating shaft 4 and the stationary blade 11 (actually, an annular stationary member that holds the inner peripheral end of the stationary blade 11). A leaf seal 20 is provided as a shaft seal mechanism for reducing the above.

また、圧縮機１は回転軸４にてタービン３と同軸につながれており、タービン３での回転軸４の回転を利用して、外気を吸引するとともに圧縮してこの圧縮空気を燃焼機２に供給する。圧縮機１でもタービン３と同様に、回転軸４に複数の動翼６と、圧縮機１のケーシング５側に複数の静翼７とが設けられており、動翼６と静翼７とが回転軸４の軸方向に交互に配置される。そして、回転軸４と静翼７（ここでも実際には、静翼７の内周端を保持する環状の静止部材）との間には、その隙間を通じて高圧側から低圧側に漏れる圧縮空気の漏れ量を低減するための軸シール機構として、リーフシール２０が設けられる。   The compressor 1 is coaxially connected to the turbine 3 at the rotating shaft 4, and uses the rotation of the rotating shaft 4 in the turbine 3 to suck and compress outside air into the combustor 2. Supply. In the compressor 1, similarly to the turbine 3, a plurality of moving blades 6 are provided on the rotating shaft 4, and a plurality of stationary blades 7 are provided on the casing 5 side of the compressor 1. The rotating shafts 4 are alternately arranged in the axial direction. The compressed air leaking from the high pressure side to the low pressure side through the gap between the rotating shaft 4 and the stationary blade 7 (here, actually, an annular stationary member that holds the inner peripheral end of the stationary blade 7). A leaf seal 20 is provided as a shaft seal mechanism for reducing the amount of leakage.

更に、圧縮機１のケーシング５が回転軸４を支持する軸受け部８や、タービン３のケーシング９が回転軸４を支持する軸受け部１２においても、その隙間を通じて高圧側から低圧側に圧縮空気や燃焼ガスが漏れるのを防止するための軸シール機構として、リーフシール２０が設けられる。   Further, in the bearing portion 8 where the casing 5 of the compressor 1 supports the rotating shaft 4 and the bearing portion 12 where the casing 9 of the turbine 3 supports the rotating shaft 4, compressed air or A leaf seal 20 is provided as a shaft seal mechanism for preventing combustion gas from leaking.

続いて図９及び図１０に示すように、リーフシール２０は、静翼７，１１及び軸受け部９１２（図８参照）に相当する静止部材であるステータ６０に挿入されて、回転軸４の周面とステータ６０の内周面との隙間の環状空間におけるガスの漏れを防ぐための軸シール機構として設置される。このリーフシール２０は、回転軸４の周方向に互いに微小隙間を隔てて多重に積み重ねられた複数の薄板２１より成る環状の薄板群と（図１１（ａ）参照）、この薄板群を薄板２１の外周基端側において軸方向での両側から挟持する各々コの字型のリテーナ２２，２３と、薄板群における高圧側（ガス圧が高い側）に位置する一側と一方のリテーナ２２とで挟み込まれて薄板群のその一側に接触する分割環状の高圧側側板２４と、薄板群における低圧側（ガス圧が低い側）に位置する他側と他方のリテーナ２３とで挟み込まれて薄板群のその他側に接触する分割環状の低圧側側板２５と、リテーナ２２，２３同士を薄板２１の外周側で接続する接続部材２６と、リテーナ２２，２３で狭持された各薄板２１のがたつきを抑制するスペーサ２７と、リテーナ２２，２３で狭持された薄板群が回転軸４に対して一定位置となるように付勢力を与える板バネ２８と、を備える。   Subsequently, as shown in FIGS. 9 and 10, the leaf seal 20 is inserted into the stator 60, which is a stationary member corresponding to the stationary blades 7 and 11 and the bearing portion 912 (see FIG. 8). It is installed as a shaft seal mechanism for preventing gas leakage in the annular space in the gap between the surface and the inner peripheral surface of the stator 60. The leaf seal 20 includes an annular thin plate group composed of a plurality of thin plates 21 (see FIG. 11 (a)) that are stacked in multiple layers in the circumferential direction of the rotating shaft 4 with a minute gap therebetween, and the thin plate group is formed into a thin plate 21. Each of the U-shaped retainers 22 and 23 sandwiched from both sides in the axial direction on the outer peripheral proximal end side, and one side and one retainer 22 located on the high pressure side (the gas pressure side) in the thin plate group The thin plate group is sandwiched between the divided annular high-pressure side plate 24 that is sandwiched and contacts one side of the thin plate group, the other side located on the low-pressure side (the low gas pressure side) of the thin plate group, and the other retainer 23. Of the divided annular low-pressure side plate 25 in contact with the other side, the connecting member 26 that connects the retainers 22 and 23 on the outer peripheral side of the thin plate 21, and rattling of the thin plates 21 held by the retainers 22 and 23. Spacer 27 to suppress Comprises a leaf spring 28 which sheet group that is grasped by the retainer 22, 23 provide a biasing force to be constant position with respect to the rotation axis 4, a.

薄板群の構成要素である各薄板２１は、図１０に示すように、外周側基端における回転軸４の軸方向での幅が内周端側の幅に比べて広い略Ｔ字型の薄い鋼板によって構成され、その両側には、その幅の段差部分において切欠き部２１ａ，２１ｂが設けられる。ここで、各薄板２１は、圧延成形された厚さ０．１ｍｍ程度の鋼板（例えばステンレス、インコネル、ハステロイ等の金属鋼板）を素材とし、これをプレス等によって型抜きすることで先ずは一定厚さの所定形状（Ｔ字型）に成形される。そして、図１２に示すように、この薄板２１の外周側基端部をそのまま残しつつ内周端側の片面のみ（図１２の網掛け部分２１ｄに相当）をエッチングして取り除くことで、その厚みに段差が形成される。但し、こうしたＴ字型の輪郭形成と段差形成とをエッチングによって同時に成形することも可能である。   As shown in FIG. 10, each thin plate 21 that is a constituent element of the thin plate group has a substantially T-shaped thin shape in which the width in the axial direction of the rotary shaft 4 at the outer peripheral side base end is wider than the width at the inner peripheral end side. It is made of a steel plate, and on both sides thereof, notches 21a and 21b are provided at the stepped portions of the width. Here, each thin plate 21 is made of a rolled steel plate having a thickness of about 0.1 mm (for example, a metal steel plate made of stainless steel, Inconel, Hastelloy, etc.), and is first die-cut with a press or the like to obtain a constant thickness. It is molded into a predetermined shape (T-shape). Then, as shown in FIG. 12, the thickness of the thin plate 21 is removed by etching and removing only one side (corresponding to the shaded portion 21d in FIG. 12) of the inner peripheral end side while leaving the outer peripheral base end portion as it is. A step is formed. However, it is also possible to simultaneously form such T-shaped contour formation and step formation by etching.

このような薄板２１を回転軸４の軸方向に同一の幅となるように重ねるとともに、図１１（ｂ）に示すように、その外周基端及び外周基端側となる幅広部分の側面に溶接Ｗｄを施して固定し、これにより薄板群が形成される。また、各薄板２１はエッチングされた内周端側の板厚ｔで決まる所定の剛性を回転軸４の周方向に持つように設計されるとともに、回転軸４の回転方向に対して回転軸４の周面となす角θが鋭角となるようにリテーナ２２，２３で保持される。なお、薄板群においては、各薄板２１のエッチングにて取り除かれる部分２１ｄの深さｃが、薄板２１同士の微小隙間となる。   Such thin plates 21 are stacked so as to have the same width in the axial direction of the rotary shaft 4 and, as shown in FIG. 11B, welded to the side surfaces of the outer peripheral base end and the wide portion serving as the outer peripheral base end side. Wd is applied and fixed, whereby a thin plate group is formed. In addition, each thin plate 21 is designed to have a predetermined rigidity in the circumferential direction of the rotating shaft 4 determined by the etched thickness t on the inner peripheral end side, and the rotating shaft 4 with respect to the rotating direction of the rotating shaft 4. Is held by retainers 22 and 23 so that the angle θ formed with the peripheral surface of the above becomes an acute angle. In the thin plate group, the depth c of the portion 21d removed by etching of each thin plate 21 is a minute gap between the thin plates 21.

高圧側側板２４及び低圧側側板２５には、それぞれの外周縁部において、回転軸４の軸方向に突出する突起２４ａ，２５ａが設けられており、この突起２４ａ，２５ａは、薄板群の切欠き部２１ａ，２１ｂにそれぞれ嵌め込まれる。また、高圧側に位置するリテーナ２２は、薄板群における外周基端側の高圧側である一側に対向する面に凹溝２２ａを備え、他方の低圧側に位置するリテーナ２３は、薄板群における外周基端側の低圧側である他側に対向する面に凹溝２３ａを備える。そして、切欠き部２１ａ，２１ｂに高圧側側板２４及び低圧側側板２５それぞれの突起２４ａ，２５ａが嵌め込まれた薄板群は、その外周基端側の高圧側である一側がリテーナ２２の凹溝２２ａに嵌め込まれるとともに、その外周基端側の低圧側である他側がリテーナ２３の凹溝２３ａに嵌め込まれる。   The high-pressure side plate 24 and the low-pressure side plate 25 are provided with protrusions 24a and 25a that protrude in the axial direction of the rotary shaft 4 at the outer peripheral edge portions, and these protrusions 24a and 25a are notches of the thin plate group. The parts 21a and 21b are respectively fitted. Further, the retainer 22 located on the high pressure side has a concave groove 22a on the surface facing the one side which is the high pressure side on the outer peripheral base end side in the thin plate group, and the retainer 23 located on the other low pressure side is in the thin plate group. A groove 23a is provided on the surface facing the other side which is the low pressure side on the outer peripheral base end side. In the thin plate group in which the protrusions 24a and 25a of the high-pressure side plate 24 and the low-pressure side plate 25 are fitted into the notches 21a and 21b, one side which is the high-pressure side on the outer peripheral base end side is the concave groove 22a of the retainer 22. And the other side, which is the low-pressure side of the outer peripheral base end side, is fitted into the recessed groove 23 a of the retainer 23.

ここで、高圧側側板２４は、その内径が回転軸の径よりも若干量大きく、低圧側側板２５は、その内径が高圧側側板２４の内径よりも所定量大きくなっている。従って、薄板群における各薄板２１の内周端部は、高圧側である一側よりも低圧側である他側の方が軸方向での表出域がはるかに大きくなる。   Here, the inner diameter of the high-pressure side plate 24 is slightly larger than the diameter of the rotating shaft, and the inner diameter of the low-pressure side plate 25 is larger than the inner diameter of the high-pressure side plate 24 by a predetermined amount. Accordingly, the inner peripheral end portion of each thin plate 21 in the thin plate group has a much larger exposed area in the axial direction on the other side, which is the low pressure side, than one side, which is the high pressure side.

薄板群の外周基端側が嵌め込まれたリテーナ２２，２３の間には、接続部材２６が挿入されるとともに、この接続部材２６がリテーナ２２，２３と溶接されることで、リテーナ２２，２３が固定される。薄板群の外周基端とリテーナ２２，２３との間には、両者の隙間を埋めるスペーサ２７が挿入される。更に、スペーサ２７が挿入されたリテーナ２２，２３の外周側には凹溝２２ｂ，２３ｂが設けられていて、この凹溝２２ｂ，２３ｂによって形成される１つの凹溝に板バネ２８が嵌め込まれ、これにより板バネ２８がリテーナ２２，２３の外周側に固定される。   A connecting member 26 is inserted between the retainers 22 and 23 in which the outer peripheral proximal end side of the thin plate group is fitted, and the connecting members 26 are welded to the retainers 22 and 23 so that the retainers 22 and 23 are fixed. Is done. A spacer 27 is inserted between the outer peripheral proximal end of the thin plate group and the retainers 22 and 23 to fill the gap between them. Furthermore, concave grooves 22b and 23b are provided on the outer peripheral sides of the retainers 22 and 23 into which the spacers 27 are inserted, and a leaf spring 28 is fitted into one concave groove formed by the concave grooves 22b and 23b. As a result, the leaf spring 28 is fixed to the outer peripheral side of the retainers 22 and 23.

このような構成のリーフシール２０は、図１０に示すように、分割環状の取付け用ピース６２と一体で、ステータ６０側の内周壁面に周方向に沿って形成された環状の取付け用凹溝６１に、リテーナ２２，２３側から周方向に沿って嵌め込まれる。ここで、凹溝６１は、回転軸４の軸方向において、底となる外周側の幅が内周側の幅よりも広くなるように、薄板群の高圧側である一側と対向する側面に段差が設けられた形状とし、この段差の外周側の面６１ａが、リーフシール２０のリテーナ２２の内周面と摺接する摺接面となる。更に、凹溝６１の底である外周面６１ｂが、リーフシール２０の外周側に設けられる板バネ２８と摺接する摺接面となる。また、凹溝６１の内周側の幅は、回転軸４の軸方向の幅において、リーフシール２０の幅よりも十分に広くなるように形成される。   As shown in FIG. 10, the leaf seal 20 having such a configuration is an annular mounting groove formed integrally with a split annular mounting piece 62 and formed along the circumferential direction on the inner peripheral wall surface on the stator 60 side. 61, the retainers 22 and 23 are fitted along the circumferential direction. Here, the concave groove 61 is formed on the side surface facing the one side which is the high pressure side of the thin plate group so that the width on the outer peripheral side serving as the bottom is wider than the width on the inner peripheral side in the axial direction of the rotation shaft 4. The shape is provided with a step, and the surface 61 a on the outer peripheral side of the step is a sliding contact surface that is in sliding contact with the inner peripheral surface of the retainer 22 of the leaf seal 20. Further, the outer peripheral surface 61 b that is the bottom of the concave groove 61 is a sliding contact surface that comes into sliding contact with the leaf spring 28 provided on the outer peripheral side of the leaf seal 20. Further, the inner circumferential side width of the concave groove 61 is formed to be sufficiently wider than the width of the leaf seal 20 in the axial width of the rotating shaft 4.

一方、取付け用ピース６２は、回転軸４の軸方向において、図１０に示すように、外周側の幅が内周側の幅よりも狭くなるように、薄板群の低圧側である他側と対向する側面に段差が設けられた形状とし、この段差の外周側の面６２ａが、リーフシール２０のリテーナ２３の内周面と摺接する摺接面となる。更に、この取付け用ピース６２は、回転軸４の軸方向での幅の広い内周側の部分において、薄板群の低圧側である他側と対向する側面６２ｂが、低圧側側板２５と当接する受圧面となる。なお、この取付け用ピース６２の内周面の一部を突出させた形状とすることで、ラビリンスシール６２ｄを具備する。つまり、リーフシール２０の下流側に取付け用ピース６２が設置され、これにより、リーフシール２０よりも下流において、ガスの漏れ量を更に低減させるラビリンスシール６２ｄが設置されることとなる。   On the other hand, as shown in FIG. 10, in the axial direction of the rotating shaft 4, the mounting piece 62 is connected to the other side, which is the low pressure side of the thin plate group, so that the width on the outer peripheral side is narrower than the width on the inner peripheral side. A step is provided on the opposite side surface, and the outer surface 62a of the step is a sliding contact surface that is in sliding contact with the inner peripheral surface of the retainer 23 of the leaf seal 20. Further, in the mounting piece 62, the side surface 62 b facing the other side which is the low pressure side of the thin plate group is in contact with the low pressure side plate 25 in the wide inner peripheral side portion in the axial direction of the rotating shaft 4. It becomes the pressure receiving surface. Note that a labyrinth seal 62d is provided by projecting a part of the inner peripheral surface of the mounting piece 62. That is, the mounting piece 62 is installed on the downstream side of the leaf seal 20, and thereby, the labyrinth seal 62 d for further reducing the amount of gas leakage is installed downstream of the leaf seal 20.

このように、リーフシール２０は、取付け用ピース６２と共に、ステータ６０の凹溝６１に対しその外周基端側で保持されることとなる。つまり、リテーナ２２，２３それぞれの内周面が、凹溝６１の摺接面６１ａ及び取付け用ピース６２の摺接面６２ａと摺接するとともに、リテーナ２２，２３の外周側に固定された板バネ２８が凹溝６１の摺接面６１ｂと摺接することで、リーフシール２０がステータ６０に対して嵌め込まれた状態で維持される。ちなみに、取付け用ピース６２を用いてリーフシール２０がステータ６０の凹溝６１に嵌め込まれるため、その組み付け作業を容易に行うことができる。   As described above, the leaf seal 20 is held together with the mounting piece 62 on the outer peripheral proximal end side with respect to the concave groove 61 of the stator 60. That is, the inner peripheral surfaces of the retainers 22 and 23 are in sliding contact with the sliding contact surface 61a of the recessed groove 61 and the sliding contact surface 62a of the mounting piece 62, and are fixed to the outer peripheral side of the retainers 22 and 23. Is in sliding contact with the sliding contact surface 61 b of the concave groove 61, so that the leaf seal 20 is maintained in a state of being fitted to the stator 60. Incidentally, since the leaf seal 20 is fitted into the concave groove 61 of the stator 60 using the mounting piece 62, the assembling work can be easily performed.

このとき、リーフシール２０は、凹溝６１内に対して、回転軸４の軸方向に若干の相対移動が可能である。そのため、高圧側領域から低圧側領域に向かってガスが流れるとき、そのガス圧がリーフシール２０の各薄板２１に作用するため、リーフシール２０が低圧側領域に向かって移動し、後述するように、低圧側側板２５が取付け用ピース６２の受圧面６２ｂと当接するようになる。   At this time, the leaf seal 20 can move slightly in the axial direction of the rotary shaft 4 with respect to the inside of the concave groove 61. Therefore, when gas flows from the high pressure side region toward the low pressure side region, the gas pressure acts on each thin plate 21 of the leaf seal 20, so that the leaf seal 20 moves toward the low pressure side region, as will be described later. The low-pressure side plate 25 comes into contact with the pressure receiving surface 62 b of the mounting piece 62.

引き続き、このように構成されるリーフシール２０の作用について説明する。図１３（ａ）に示すように、高圧側領域から低圧側領域に向かうガス圧が各薄板２１に加わった場合に、各薄板２１に対して、内周端側で且つ最も高圧側領域に位置する角部ｒ１で最もガス圧が高く、対角の角部ｒ２に向かって徐々にガス圧が弱まるガス圧分布７０ａが形成される。なお、図１０では各薄板２１をＴ字型形状としているが、図９や図１３では、便宜上、撓みを生じる長方形部分のみを図示している。   Next, the operation of the leaf seal 20 configured as described above will be described. As shown in FIG. 13A, when a gas pressure from the high pressure side region toward the low pressure side region is applied to each thin plate 21, it is located on the inner peripheral end side and the highest pressure side region with respect to each thin plate 21. A gas pressure distribution 70a is formed in which the gas pressure is highest at the corner r1 and the gas pressure gradually decreases toward the diagonal corner r2. In FIG. 10, each thin plate 21 has a T-shape. However, in FIG. 9 and FIG. 13, only a rectangular portion that causes bending is illustrated for convenience.

また、図１３（ｂ）に示す回転軸４の周方向に沿った断面図のように、各薄板２１の回転軸４に面した面を下面２１ｑとするとともに、その裏側を上面２１ｐとする。そして、各薄板２１に対して高圧側領域から低圧側領域に向かうガス圧が加わって、図１３（ａ）のようなガス圧分布７０ａが形成されるとき、各薄板２１の断面に沿った任意位置における上面２１ｐに加わるガス圧よりも下面２１ｑに加わるガス圧の方が高くなるように、ガス圧が調整される。   Further, as shown in the cross-sectional view along the circumferential direction of the rotating shaft 4 shown in FIG. 13B, the surface facing the rotating shaft 4 of each thin plate 21 is a lower surface 21q, and the back side is an upper surface 21p. And when the gas pressure which goes to a low voltage | pressure side area | region from a high voltage | pressure side area | region is added with respect to each thin plate 21, and the gas pressure distribution 70a as shown to Fig.13 (a) is formed, arbitrary along the cross section of each thin plate 21 The gas pressure is adjusted so that the gas pressure applied to the lower surface 21q is higher than the gas pressure applied to the upper surface 21p at the position.

このとき、高圧側領域から低圧側領域に向かって流れるガスｇは、高圧側側板２４と回転軸４の周面との間から流入する。そして、ガスｇは、図１３（ａ）のように、回転軸４の周面と薄板２１の内周端との間を流れるとともに、互いに隣接する各薄板２１の上面２１ｐ及び下面２１ｑとの隙間に沿って、角部ｒ１から角部ｒ２の方向へ放射状に流れる。このようにガスｇが流れることで、各薄板２１の外周基端に向かって低圧の領域が広がる。そのため、図１３（ｂ）に示すように、各薄板２１の上面２１ｐ及び下面２１ｑに垂直に加わるガス圧分布７０ｂ，７０ｃは、各薄板２１の内周端部分に近いほど大きくなるとともに各薄板２１の外周基端に向かうほど小さくなる三角分布形状となる。   At this time, the gas g flowing from the high pressure side region toward the low pressure side region flows from between the high pressure side plate 24 and the peripheral surface of the rotating shaft 4. As shown in FIG. 13A, the gas g flows between the peripheral surface of the rotating shaft 4 and the inner peripheral end of the thin plate 21, and the gap between the upper surface 21p and the lower surface 21q of the adjacent thin plates 21. , And flows radially from the corner r1 to the corner r2. As the gas g flows in this manner, a low-pressure region expands toward the outer peripheral base end of each thin plate 21. Therefore, as shown in FIG. 13 (b), the gas pressure distributions 70b and 70c applied perpendicularly to the upper surface 21p and the lower surface 21q of each thin plate 21 become larger and closer to the inner peripheral end portion of each thin plate 21 and each thin plate 21. It becomes a triangular distribution shape that becomes smaller as it goes toward the outer periphery base end.

この上面２１ｐ及び下面２１ｑそれぞれにおけるガス圧力分布７０ｂ，７０ｃは、略等しい形状となるが、回転軸４の周面に対する角度θが鋭角となるように各薄板２１が配置されているので、これら上面２１ｐ及び下面２１ｑにおける各ガス圧分布７０ｂ，７０ｃの相対位置が薄板２１に対してずれる。これにより、薄板２１の外周基端側から内周端側に向かう任意の点Ｐにおける上面２１ｐ及び下面２１ｑのガス圧に差が生じる。こうして、各薄板２１において、下面２１ｑに加わるガス圧が上面２１ｐに加わるガス圧よりも高くなることから、回転軸４の周面と薄板２１の内周端との間を流れるガスのガス圧が、各薄板２１の内周端を回転軸４より浮かせる方向に発生する。   The gas pressure distributions 70b and 70c on the upper surface 21p and the lower surface 21q have substantially the same shape, but the thin plates 21 are arranged so that the angle θ with respect to the peripheral surface of the rotating shaft 4 is an acute angle. The relative positions of the gas pressure distributions 70b and 70c on 21p and the lower surface 21q are shifted from the thin plate 21. Thereby, a difference arises in the gas pressure of the upper surface 21p and the lower surface 21q in the arbitrary points P which go to the inner peripheral end side from the outer peripheral base end side of the thin plate 21. Thus, in each thin plate 21, the gas pressure applied to the lower surface 21q is higher than the gas pressure applied to the upper surface 21p, so that the gas pressure of the gas flowing between the peripheral surface of the rotating shaft 4 and the inner peripheral end of the thin plate 21 is reduced. The inner peripheral edge of each thin plate 21 is generated in the direction of floating from the rotary shaft 4.

このように、各薄板２１の上面２１ｐ及び下面２１ｑ間に圧力差を生じさせることで、各薄板２１の内周端が回転軸４の周面より浮くように変形する。つまり、回転軸４の回転停止時には薄板２１の内周端は所定の予圧で回転軸４の周面に接触しているが（図１１（ａ）参照）、回転軸４の回転時には回転軸４が回転することで生じる動圧効果によって薄板２１の内周端が浮上するため、薄板２１と回転軸４の周面が非接触状態となる（図１１（ｃ）参照）。こうして、リーフシール２０は、回転軸４の周囲の空間を高圧側領域と低圧側領域とに分け、回転軸４の外周をシールする。   In this way, by generating a pressure difference between the upper surface 21p and the lower surface 21q of each thin plate 21, the inner peripheral end of each thin plate 21 is deformed so as to float above the peripheral surface of the rotating shaft 4. That is, when the rotation shaft 4 stops rotating, the inner peripheral end of the thin plate 21 is in contact with the peripheral surface of the rotation shaft 4 with a predetermined preload (see FIG. 11A), but when the rotation shaft 4 rotates, the rotation shaft 4 Since the inner peripheral end of the thin plate 21 is lifted by the dynamic pressure effect generated by the rotation, the thin plate 21 and the peripheral surface of the rotary shaft 4 are in a non-contact state (see FIG. 11C). Thus, the leaf seal 20 divides the space around the rotary shaft 4 into a high pressure side region and a low pressure side region, and seals the outer periphery of the rotary shaft 4.

その際、このようにガスｇが高圧側領域から低圧側領域に向かって流れるため、薄板群に対して、図１４（ａ）に示すように、高圧側領域から低圧側領域に向かって流体力Ｆが作用する。この流体力Ｆを薄板群が受けることで、リーフシール２０が高圧側領域から低圧側領域に向かって移動する。そして、図１４（ｂ）に示すように、低圧側側板２５が取付け用ピース６２の受圧面６２ｂに当接することで、リーフシール２０の位置が規制され、このとき、薄板群における低圧側である他側と取付け用ピース６２の受圧面６２ｂとの距離が、低圧側側板２５の厚さと等しくなる。   At this time, since the gas g flows from the high-pressure side region to the low-pressure side region in this way, as shown in FIG. 14 (a), the fluid force is applied from the high-pressure side region to the low-pressure side region. F acts. When the thin plate group receives the fluid force F, the leaf seal 20 moves from the high pressure side region toward the low pressure side region. And as shown in FIG.14 (b), the position of the leaf seal 20 is controlled when the low voltage | pressure side board 25 contact | abuts to the pressure receiving surface 62b of the piece 62 for attachment, At this time, it is the low voltage | pressure side in a thin-plate group. The distance between the other side and the pressure receiving surface 62 b of the mounting piece 62 is equal to the thickness of the low pressure side plate 25.

これは、低圧側側板２５の内径が薄板群の内径よりも大きいため、薄板群における各薄板２１の内周端側において、低圧側側板２５と当接しない表出域が存在することになるからであり、その結果として、薄板群における各薄板２１の内周端側において、低圧側である他側と取付け用ピース６２の受圧面６２ｂとの間に、低圧側側板２５の厚さと等しい隙間を確保できるわけである。一方、高圧側側板２４の内径が低圧側側板２５の内径よりも小さいことから、結果として、薄板群における各薄板２１の内周端側において、高圧側での表出域が低圧側での表出域よりも小さくなる。   This is because, since the inner diameter of the low-pressure side plate 25 is larger than the inner diameter of the thin plate group, there is an exposed area that does not contact the low-pressure side plate 25 on the inner peripheral end side of each thin plate 21 in the thin plate group. As a result, on the inner peripheral end side of each thin plate 21 in the thin plate group, a gap equal to the thickness of the low pressure side plate 25 is provided between the other side which is the low pressure side and the pressure receiving surface 62b of the mounting piece 62. It can be secured. On the other hand, since the inner diameter of the high-pressure side plate 24 is smaller than the inner diameter of the low-pressure side plate 25, as a result, on the inner peripheral end side of each thin plate 21 in the thin plate group, the exposed area on the high pressure side is the surface on the low pressure side. It becomes smaller than the departure area.

従って、図１３（ａ）のように、高圧側側板２４の内周面と回転軸４の周面との隙間を通じて各薄板２１（薄板群）へ流入したガスｇは、各薄板２１の上面２１ｐ及び下面２１ｑに沿って対角に向かって広く流れるとともに、薄板２１の外周基端側に低圧の領域が広がって、各薄板２１の内周端を回転軸４の周面から浮上させ、低圧側側板２５の内周面と回転軸４の周面との隙間を通じて流出する。このように、高圧側側板２４及び低圧側側板２５は、各薄板２１の内周端を有効に浮上させるべく、各薄板２１へのガスの流入量やガス圧を調整するというリーフシール２０にとって重要な機能を果たす。   Therefore, as shown in FIG. 13A, the gas g flowing into each thin plate 21 (thin plate group) through the gap between the inner peripheral surface of the high-pressure side plate 24 and the peripheral surface of the rotary shaft 4 is the upper surface 21p of each thin plate 21. And the lower plate 21q flows widely in a diagonal direction, and a low pressure region spreads on the outer peripheral proximal end side of the thin plate 21, so that the inner peripheral end of each thin plate 21 floats from the peripheral surface of the rotating shaft 4, It flows out through the gap between the inner peripheral surface of the side plate 25 and the peripheral surface of the rotating shaft 4. Thus, the high-pressure side plate 24 and the low-pressure side plate 25 are important for the leaf seal 20 that adjusts the amount of gas flowing into each thin plate 21 and the gas pressure in order to effectively float the inner peripheral end of each thin plate 21. Fulfills the functions.

なお、上記のリーフシール２０では、各薄板２１をＴ字型形状としているが、単なる長方形状としても構わない。また、薄板群とリテーナ２２，２３との間にスペーサ２７がないものとしても構わないし、リテーナ２２，２３と接続部材２６とがボルトで固定されるものとしても構わないし、板バネ２８がないものとしても構わない。   In the leaf seal 20 described above, each thin plate 21 has a T-shape, but may have a simple rectangular shape. Further, there may be no spacer 27 between the thin plate group and the retainers 22 and 23, or the retainers 22 and 23 and the connecting member 26 may be fixed with bolts, and there is no leaf spring 28. It does not matter.

また、リーフシール２０を大型流体機械に組み付ける場合、環状の状態のまま回転軸４に軸方向に沿って挿入して取り付けることは困難であることから、回転軸４の周面に沿って環状に構成されるリーフシール２０は、実際には、図１５に示すように、その周方向に４〜８分割された複数の分割体より構成される。このとき、分割体個々の端面が回転軸４の回転方向に対して回転軸４の周面となす角度は、各薄板２１が回転軸４の周面となす角度と等しい角度となる。
特開２００２−１３６４７号公報 Further, when the leaf seal 20 is assembled to a large fluid machine, it is difficult to insert the leaf seal 20 into the rotary shaft 4 along the axial direction in an annular state, so that the leaf seal 20 is annular along the peripheral surface of the rotary shaft 4. As shown in FIG. 15, the configured leaf seal 20 is actually composed of a plurality of divided bodies that are divided into four to eight in the circumferential direction. At this time, the angle formed by each end face of each divided body with the circumferential surface of the rotating shaft 4 with respect to the rotation direction of the rotating shaft 4 is equal to the angle formed by each thin plate 21 with the circumferential surface of the rotating shaft 4.
JP 2002-13647 A

ところで、高圧側領域と低圧側領域の圧力差が極めて大きい個所のステータ６０に、上記したリーフシール２０を設置しようとする場合は、１つのリーフシール２０では、その圧力差に耐えることが困難であるため、リーフシール２０を回転軸４の軸方向に複数段に亘って設置し、これらのリーフシール２０でその圧力差を分担するようにしている。その一例として、リーフシール２０を２段に設置した状況を図１６に示す。ここでは、高圧側領域から低圧側領域に向けて順に、第１段目のリーフシール１２０、及び最終段である第２段目のリーフシール２２０が設置される。   By the way, when the leaf seal 20 is to be installed in the stator 60 where the pressure difference between the high pressure side region and the low pressure side region is extremely large, it is difficult for one leaf seal 20 to withstand the pressure difference. For this reason, the leaf seals 20 are installed in a plurality of stages in the axial direction of the rotary shaft 4, and the leaf seals 20 share the pressure difference. As an example, FIG. 16 shows a situation where the leaf seals 20 are installed in two stages. Here, a first-stage leaf seal 120 and a final-stage second-stage leaf seal 220 are installed in order from the high-pressure side region to the low-pressure side region.

第１段目のリーフシール１２０は、上記したリーフシール２０の基本構成のもと、多数の薄板１２１が積み重ねられて成る薄板群と、高圧側側板１２４と、低圧側側板１２５と、がリテーナ１２３，１２４によって保持されて成るものであり、同様に、第２段目のリーフシール２２０は、多数の薄板２２１が積み重ねられて成る薄板群と、高圧側側板２２４と、低圧側側板２２５と、がリテーナ２２３，２２４によって保持されて成るものである。ステータ６０の内周面には、第１、第２のリーフシール１２０、２２０それぞれを取り付けるための周方向に沿う環状の取付け用凹溝１６１、２６１が、回転軸４の軸方向に所定間隔をあけて形成されている。第１のリーフシール１２０は、分割環状の取付け用ピース１６２と一体で、凹溝１６１に周方向に沿って嵌め込まれ、同様に、第２のリーフシール２２０は、分割環状の取付け用ピース２６２と一体で、凹溝２６１に周方向に沿って嵌め込まれる。こうして第１、第２のリーフシール１２０、２２０がステータ６０に固定される。   The first-stage leaf seal 120 includes a thin plate group in which a large number of thin plates 121 are stacked, a high-pressure side plate 124, and a low-pressure side plate 125 based on the basic structure of the leaf seal 20 described above. Similarly, the second-stage leaf seal 220 includes a thin plate group in which a large number of thin plates 221 are stacked, a high-pressure side plate 224, and a low-pressure side plate 225. It is held by retainers 223 and 224. On the inner peripheral surface of the stator 60, annular mounting grooves 161, 261 along the circumferential direction for mounting the first and second leaf seals 120, 220 are arranged at predetermined intervals in the axial direction of the rotary shaft 4. Open and formed. The first leaf seal 120 is integral with the split annular mounting piece 162 and is fitted in the concave groove 161 along the circumferential direction. Similarly, the second leaf seal 220 is separated from the split annular mounting piece 262. It is integrally fitted in the concave groove 261 along the circumferential direction. Thus, the first and second leaf seals 120 and 220 are fixed to the stator 60.

また、別例として、図１７に示すように、第１、第２のリーフシール１２０、２２０を分割環状のホルダ９０を中間的に介在して、ステータ６０に取り付ける場合もある。この場合、ステータ６０の内周面には、ホルダ９０を取り付けるための周方向に沿う環状の取付け用凹溝９１が形成されている。一方、ホルダ９０の内周面には、第１、第２のリーフシール１２０、２２０それぞれを取り付けるための周方向に沿う環状の取付け用凹溝１６１、２６１が、図１６と同様に、回転軸４の軸方向に所定間隔をあけて形成されている。第１、第２のリーフシール１２０、２２０は、分割環状の各取付け用ピース１６２、２６２と一体で、各凹溝１６１、２６１に周方向に沿って嵌め込まれ、ホルダ９０に固定される。そして、このホルダ９０は凹溝９１に周方向に沿って嵌め込まれる。こうして第１、第２のリーフシール１２０、２２０がステータ６０に対して固定される。   As another example, as shown in FIG. 17, the first and second leaf seals 120 and 220 may be attached to the stator 60 with a split annular holder 90 interposed therebetween. In this case, an annular mounting groove 91 along the circumferential direction for mounting the holder 90 is formed on the inner peripheral surface of the stator 60. On the other hand, on the inner peripheral surface of the holder 90, annular mounting grooves 161, 261 along the circumferential direction for mounting the first and second leaf seals 120, 220, respectively, are arranged in the same manner as in FIG. 4 are formed at predetermined intervals in the axial direction. The first and second leaf seals 120, 220 are integrated with the split annular mounting pieces 162, 262, fitted in the concave grooves 161, 261 along the circumferential direction, and fixed to the holder 90. The holder 90 is fitted in the concave groove 91 along the circumferential direction. Thus, the first and second leaf seals 120 and 220 are fixed to the stator 60.

しかし、これらのような複数段のリーフシール２０（第１、第２のリーフシール１２０、２２０）の設置態様では、リーフシール２０ごとに、回転軸４の軸方向である程度幅広い凹溝６１（凹溝１６１、２６１）を備える上、各凹溝６１同士の間にもある程度のスペースの確保を必要とする、すなわちリーフシール２０同士の間にある程度の間隔が必要であることから、必然的に回転軸４も長くなる。そうすると、これが適用される流体機械の軸方向への大型化を招き、回転軸４の軸振動の発生にも敏感になるという弊害がある。この問題は、リーフシール２０の設置段数を増すほど顕著である。   However, in the installation mode of the multi-stage leaf seals 20 (first and second leaf seals 120 and 220) as described above, each of the leaf seals 20 has a somewhat wide groove 61 (recessed in the axial direction of the rotating shaft 4). In addition to providing the grooves 161 and 261), it is necessary to ensure a certain amount of space between the concave grooves 61, that is, a certain amount of space between the leaf seals 20 is necessary, and therefore the rotation is necessarily performed. The axis 4 also becomes longer. If it does so, the enlargement to the axial direction of the fluid machine to which this is applied will be caused, and there exists a bad effect that it becomes sensitive also to generation | occurrence | production of the axial vibration of the rotating shaft 4. FIG. This problem becomes more prominent as the number of installation stages of the leaf seal 20 is increased.

もっとも、各リーフシール２０をこれ単体でステータ６０やホルダ９０に取り付けることが可能であれば、取付け用ピース６２（取付け用ピース１６２、２６２）の分軸方向での幅を抑えることができるはずである。ところが現実には、特有の形状を有するリーフシール２０単体を周方向に沿って収めることが可能な凹溝を形成するのは、加工上で不可能に近い。結局のところ、上記したように、加工上で無理のない程度で凹溝６１を幅広く形成し、取付け用ピース６２を持ってしてリーフシール２０との隙間を埋めるようにしたわけである。   However, if each of the leaf seals 20 can be attached to the stator 60 or the holder 90 as a single unit, the width of the mounting piece 62 (the mounting pieces 162 and 262) in the partial axis direction can be suppressed. is there. However, in reality, it is almost impossible to form a concave groove capable of accommodating the leaf seal 20 having a specific shape along the circumferential direction. After all, as described above, the concave groove 61 is formed in a wide range with a reasonable degree of processing, and the gap with the leaf seal 20 is filled by holding the mounting piece 62.

そこで本発明は、上記の問題に鑑みてなされたものであり、リーフシールを複数段備えた軸シール機構であって、回転軸の長さを抑えることのできる軸シール機構を提供することを目的とするものである。   Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a shaft seal mechanism including a plurality of stages of leaf seals and capable of suppressing the length of a rotating shaft. It is what.

上記目的を達成するため、本発明による軸シール機構は、回転軸の周面とこの回転軸に同軸状で静止した静止部材の内周面との隙間においての高圧側から低圧側への作動流体の漏れを抑える軸シール機構であって、前記回転軸の軸方向に一定幅を有し、各々が前記回転軸の周方向へ互いに微小隙間を隔てながら前記回転軸の周面に対して鋭角に積み重ねられつつ、各々の内周端が回転停止時の前記回転軸の周面に接触する可撓性のある多数の薄板より成る環状の薄板群と、この薄板群における軸方向での両側のうちの高圧側に位置する一側に当接し、前記回転軸の径よりも所定量大きい内径を有する環状の高圧側側板と、前記薄板群における軸方向での両側のうちの低圧側に位置する他側に当接し、前記高圧側側板の内径よりも所定量大きい内径を有する環状の低圧側側板と、前記薄板群、前記高圧側側板、及び前記低圧側側板をこれらの外周部で一体に保持する環状の保持部材と、より成る周方向に分割可能な軸シール部材を、前記静止部材に対して軸方向へ複数段取り付けた軸シール機構において、以下の点を特徴とする。   In order to achieve the above object, the shaft seal mechanism according to the present invention provides a working fluid from a high pressure side to a low pressure side in a gap between a peripheral surface of a rotating shaft and an inner peripheral surface of a stationary member that is coaxial and stationary on the rotating shaft. A shaft seal mechanism that suppresses leakage of the rotary shaft, and has a certain width in the axial direction of the rotary shaft, and each of them has an acute angle with respect to the peripheral surface of the rotary shaft with a small gap therebetween in the circumferential direction of the rotary shaft. An annular thin plate group consisting of a plurality of flexible thin plates whose inner peripheral ends are in contact with the peripheral surface of the rotating shaft when rotation is stopped, and both sides of the thin plate group in the axial direction. An annular high-pressure side plate that has an inner diameter that is a predetermined amount larger than the diameter of the rotary shaft, and that is located on the low-pressure side of both sides in the axial direction of the thin plate group. A predetermined amount larger than the inner diameter of the high-pressure side plate. An axial low-pressure side plate having a diameter, an annular holding member that integrally holds the thin plate group, the high-pressure side plate, and the low-pressure side plate at their outer peripheral portions, and a shaft seal that can be divided in the circumferential direction. The shaft sealing mechanism in which a plurality of members are axially attached to the stationary member in the axial direction is characterized by the following points.

第１の特徴点としては、前記静止部材の内周面に周方向に沿う取付け用溝が形成されていて、互いに隣接する前記各段の前記各軸シール部材同士の間に共用の取付け用部材を備えており、前記各シール部材及び前記各取付け用部材は、一体で前記取付け用溝に周方向に沿って嵌め込まれて前記静止部材に固定される。   As a first feature point, a mounting groove is formed on the inner peripheral surface of the stationary member along the circumferential direction, and the mounting member is shared between the shaft seal members of the adjacent stages. The seal members and the mounting members are integrally fitted in the mounting grooves along the circumferential direction and fixed to the stationary member.

このようにすれば、複数の軸シール部材すなわちリーフシールを静止部材に取り付けるための取付け用溝が１つで済み、しかも、回転軸の軸方向でのリーフシール同士の間隔は、両者に共用の取付け用部材が収まる程度で足りる。従って、互いに隣接するリーフシール同士の間隔を大幅に抑えることができる。勿論、その取付け用溝を静止部材に形成するにあたって、その幅が加工上で十分許容できるリーフシール及び取付け用部材をすべて含む寸法であることから、その加工にはまったく支障はない。   In this way, only one mounting groove for mounting a plurality of shaft seal members, that is, leaf seals, to the stationary member is required, and the interval between the leaf seals in the axial direction of the rotary shaft is shared by both. It is sufficient to fit the mounting member. Therefore, the interval between the leaf seals adjacent to each other can be greatly reduced. Of course, when the mounting groove is formed in the stationary member, the width thereof is a dimension including all the leaf seals and mounting members that are sufficiently allowable in processing, and therefore there is no problem in the processing.

ここで、静止部材に対するリーフシール及び取付け用部材の固定状態の安定性を確保する観点から、前記各取付け用部材は、前記静止部材へ径方向に貫通するボルトで締結されて固定されることが好ましい。同様の観点から、前記各取付け用部材は、この外周面に周方向に沿って形成された補助突起が、前記取付け用溝の底に周方向に沿って形成された補助溝に嵌合して固定されてもよい。   Here, from the viewpoint of securing the stability of the fixed state of the leaf seal and the mounting member with respect to the stationary member, each of the mounting members may be fastened and fixed to the stationary member with a bolt penetrating in the radial direction. preferable. From the same point of view, each of the mounting members has an auxiliary protrusion formed along the circumferential direction on the outer peripheral surface thereof fitted into an auxiliary groove formed along the circumferential direction at the bottom of the mounting groove. It may be fixed.

第２の特徴点としては、前記静止部材の内周面に周方向に沿う取付け用溝が形成されていて、内周面に周方向に沿う中間取付け用溝が形成された中間取付け用部材と、互いに隣接する前記各段の前記各軸シール部材同士の間に共用の取付け用部材とを備えており、前記各シール部材及び前記各取付け用部材は、一体で前記中間取付け用溝に周方向に沿って嵌め込まれて前記中間取付け用部材に固定され、前記各シール部材及び前記各取付け用部材が固定された前記中間取付け用部材は、前記取付け用溝に周方向に沿って嵌め込まれて前記静止部材に固定される。   As a second feature point, an intermediate mounting member in which a mounting groove along the circumferential direction is formed on the inner peripheral surface of the stationary member, and an intermediate mounting groove along the circumferential direction is formed on the inner peripheral surface; A common mounting member between the shaft seal members of the adjacent stages, and the seal member and the mounting member are integrated with the intermediate mounting groove in the circumferential direction. The intermediate mounting member fixed to the intermediate mounting member and fixed to the intermediate mounting member is fixed to the mounting groove along the circumferential direction. Fixed to a stationary member.

このようにすれば、複数の軸シール部材すなわちリーフシールが中間取付け用部材を介在して静止部材に取り付けられるわけであるが、それらのリーフシールを中間取付け用部材に取り付けるための取付け用溝が１つで済み、しかも、回転軸の軸方向でのリーフシール同士の間隔は、両者に共用の取付け用部材が収まる程度で足りる。従って、互いに隣接するリーフシール同士の間隔を大幅に抑えることができる。勿論、その取付け用溝を中間取付け用部材に形成するにあたって、その幅が加工上で十分許容できるリーフシール及び取付け用部材をすべて含む寸法であることから、その加工にはまったく支障はない。   In this way, a plurality of shaft seal members, i.e., leaf seals, are attached to the stationary member with the intermediate attachment member interposed therebetween, but there are mounting grooves for attaching these leaf seals to the intermediate attachment member. One spacing is sufficient, and the interval between the leaf seals in the axial direction of the rotating shaft is sufficient to accommodate a common mounting member for both. Therefore, the interval between the leaf seals adjacent to each other can be greatly reduced. Of course, when the mounting groove is formed in the intermediate mounting member, the width thereof is a dimension including all the leaf seals and mounting members that are sufficiently acceptable for processing, and therefore there is no problem in the processing.

ここで、静止部材に対するリーフシール及び取付け用部材の固定状態の安定性を確保する観点から、前記各取付け用部材は、前記中間取付け用部材を径方向に貫通するボルトで締結されて固定されることが好ましい。同様の観点から、前記各取付け用部材は、前記中間取付け用部材を軸方向に貫通するボルトで締結されて固定されてもよいし、前記各取付け用部材は、この外周面に周方向に沿って形成された補助突起が、前記中間取付け用溝の底に周方向に沿って形成された中間補助溝に嵌合して固定されてもよい。   Here, from the viewpoint of securing the stability of the fixed state of the leaf seal and the mounting member with respect to the stationary member, each of the mounting members is fastened and fixed by a bolt that penetrates the intermediate mounting member in the radial direction. It is preferable. From the same point of view, each of the mounting members may be fastened and fixed by a bolt that penetrates the intermediate mounting member in the axial direction, and each of the mounting members is arranged on the outer peripheral surface along the circumferential direction. The auxiliary protrusion formed in this manner may be fitted and fixed to the intermediate auxiliary groove formed along the circumferential direction on the bottom of the intermediate mounting groove.

また、シール機構全体としての部品点数を削減する目的で、前記各取付け用部材は、互いに隣接する前記各段の前記各シール部材を構成する前記保持部材の一部を兼ねることが好ましい。   Further, for the purpose of reducing the number of parts as a whole sealing mechanism, it is preferable that each mounting member also serves as a part of the holding member constituting each sealing member of each stage adjacent to each other.

本発明の軸シール機構によれば、回転軸の軸方向で互いに隣接するリーフシール同士の間隔を大幅に抑えることができるため、これに伴って回転軸の長さを抑えることが可能になり、リーフシールが適用される流体機械の軸方向への大型化を招くことはない。   According to the shaft seal mechanism of the present invention, the distance between the leaf seals adjacent to each other in the axial direction of the rotating shaft can be significantly suppressed, and accordingly, the length of the rotating shaft can be suppressed. The size of the fluid machine to which the leaf seal is applied is not increased in the axial direction.

以下に、本発明の実施形態であるリーフシールを採用した軸シール機構について、図面を参照しながら詳述する。先ず、本発明の第１実施形態について説明する。図１は第１実施形態におけるリーフシールを複数段備えた大型流体機械の要部を示す回転軸の軸方向に沿う断面図である。なお、図中で図８〜図１７と同じ名称で同じ機能を果たす部分には同一の符号を付し、重複する説明は適宜省略するとともに、本発明の特徴点について特筆する。特に本実施形態では、リーフシール２０を２段に設置した場合を一例として示す。後述する第２〜第７実施形態においても同様とする。   Hereinafter, a shaft seal mechanism employing a leaf seal as an embodiment of the present invention will be described in detail with reference to the drawings. First, a first embodiment of the present invention will be described. FIG. 1 is a cross-sectional view taken along the axial direction of a rotary shaft, showing the main part of a large fluid machine having a plurality of leaf seals according to the first embodiment. In the figure, parts having the same names and the same functions as those in FIGS. 8 to 17 are denoted by the same reference numerals, and redundant description will be omitted as appropriate, and feature points of the present invention will be noted. In particular, in this embodiment, the case where the leaf seals 20 are installed in two stages is shown as an example. The same applies to the second to seventh embodiments described later.

図１に示すように、ステータ６０には、回転軸４の軸方向に沿って高圧側領域から低圧側領域に向けて順に、第１段目のリーフシール１２０、及び最終段である第２段目のリーフシール２２０が設置される。ステータ６０の内周面には、第１、第２のリーフシール１２０、２２０を取り付けるための周方向に沿う環状の取付け用凹溝８１が１つだけ形成されている。第１、第２のリーフシール１２０、２２０は、これらの両者の間に軸方向で挟み込まれた分割環状の取付け用ピース１８２と一体で、凹溝８１に周方向に沿って嵌め込まれる。   As shown in FIG. 1, the stator 60 includes a first-stage leaf seal 120 and a second-stage second stage in order from the high-pressure side region to the low-pressure side region along the axial direction of the rotating shaft 4. An eye leaf seal 220 is installed. On the inner peripheral surface of the stator 60, only one annular mounting concave groove 81 is formed along the circumferential direction for mounting the first and second leaf seals 120, 220. The first and second leaf seals 120 and 220 are integrally fitted into the recessed groove 81 along the circumferential direction, integrally with a split annular mounting piece 182 sandwiched between them in the axial direction.

ここで、凹溝８１は、回転軸４の軸方向において、底となる外周側の幅が内周側の幅よりも広くなるように、第１のリーフシール１２０における薄板群の高圧側である一側と対向する側面に段差が設けられるとともに、最終段である第２のリーフシール２２０における薄板群の低圧側である他側と対向する側面に段差が設けられた形状である。これらの段差のうち、高圧側領域の方に位置する段差の外周側の面８１ａが、第１のリーフシール１２０のリテーナ１２２の内周面と摺接する摺接面となり、低圧側領域の方に位置する段差の外周側の面８１ｅが、最終段である第２のリーフシール２２０のリテーナ２２３の内周面と摺接する摺接面となる。更に、最終段である第２のリーフシール２２０における薄板群の低圧側である他側と対向する側面８１ｇが、その低圧側側板２２５と当接する受圧面となる。   Here, the concave groove 81 is on the high-pressure side of the thin plate group in the first leaf seal 120 so that the width on the outer peripheral side serving as the bottom is wider than the width on the inner peripheral side in the axial direction of the rotating shaft 4. A step is provided on the side facing the one side, and a step is provided on the side facing the other side which is the low pressure side of the thin plate group in the second leaf seal 220 which is the final stage. Of these steps, the outer peripheral surface 81a of the step located toward the high-pressure side region becomes a slidable contact surface that makes sliding contact with the inner peripheral surface of the retainer 122 of the first leaf seal 120, and toward the low-pressure side region. The surface 81e on the outer peripheral side of the step that is positioned serves as a sliding contact surface that is in sliding contact with the inner peripheral surface of the retainer 223 of the second leaf seal 220 that is the final step. Furthermore, a side surface 81 g facing the other side which is the low pressure side of the thin plate group in the second leaf seal 220 which is the final stage is a pressure receiving surface which comes into contact with the low pressure side plate 225.

また、凹溝８１の底には、取付け用ピース１８２の外周面に周方向に沿って形成された補助突起１８２ｃと嵌合する補助凹溝８１ｃが形成されていて、この補助凹溝８１ｃに対しての高圧側に位置する外周面８１ｂが、第１のリーフシール１２０の外周側に設けられる板バネ１２８と摺接する摺接面となり、他方の低圧側に位置する外周面８１ｆが、第１のリーフシール１２０に隣接する第２のリーフシール２２０の外周側に設けられる板バネ２２８と摺接する摺接面となる。   Further, an auxiliary ditch 81c is formed on the bottom of the ditch 81 so as to be fitted to an auxiliary projection 182c formed along the circumferential direction on the outer peripheral surface of the mounting piece 182. The outer peripheral surface 81b positioned on the high-pressure side is a sliding contact surface that is in sliding contact with the leaf spring 128 provided on the outer peripheral side of the first leaf seal 120, and the outer peripheral surface 81f positioned on the other low-pressure side is the first It becomes a sliding contact surface in sliding contact with a leaf spring 228 provided on the outer peripheral side of the second leaf seal 220 adjacent to the leaf seal 120.

一方、取付け用ピース１８２は、回転軸４の軸方向において、外周側の幅が内周側の幅よりも狭くなるように、第１のリーフシール１２０における薄板群の低圧側である他側と対向する側面に段差が設けられるとともに、最終段である第２のリーフシール２２０における薄板群の高圧側である一側と対向する側面に段差が設けられた形状である。これらの段差のうち、高圧側領域の方に位置する段差の外周側の面１８２ａが、第１のリーフシール１２０のリテーナ１２３の内周面と摺接する摺接面となり、低圧側領域の方に位置する段差の外周側の面１８２ｅが、第１のリーフシール１２０に隣接する第２のリーフシール２２０のリテーナ２２２の内周面と摺接する摺接面となる。更に、この取付け用ピース１８２は、回転軸４の軸方向での幅の広い内周側の部分において、第１のリーフシール１２０における薄板群の低圧側である他側と対向する側面１８２ｂが、その低圧側側板１２５と当接する受圧面となる。   On the other hand, the mounting piece 182 is arranged so that, in the axial direction of the rotary shaft 4, the width on the outer peripheral side is narrower than the width on the inner peripheral side. A step is provided on the opposite side surface, and a step is provided on the side surface facing the high pressure side of the thin plate group in the second leaf seal 220 as the final stage. Of these steps, the outer peripheral surface 182a of the step located toward the high-pressure side region becomes a sliding contact surface that is in sliding contact with the inner peripheral surface of the retainer 123 of the first leaf seal 120, and toward the low-pressure side region. The surface 182e on the outer peripheral side of the step is located as a sliding contact surface that is in sliding contact with the inner peripheral surface of the retainer 222 of the second leaf seal 220 adjacent to the first leaf seal 120. Furthermore, the mounting piece 182 has a side surface 182b facing the other side which is the low pressure side of the thin plate group in the first leaf seal 120 in the wide inner peripheral side portion in the axial direction of the rotating shaft 4. The pressure receiving surface comes into contact with the low pressure side plate 125.

こうして、取付け用ピース１８２は、軸方向で互いに隣接する第１、第２のリーフシール１２０、２２０に共用となり、第１、第２のリーフシール１２０、２２０は、共用の取付け用ピース１８２と共に、ステータ６０の凹溝８１に対しその外周基端側で保持されることとなる。つまり、リテーナ１２２，１２３それぞれの内周面が、凹溝８１の摺接面８１ａ及び取付け用ピース１８２の摺接面１８２ａと摺接するとともに、リテーナ１２２，１２３の外周側に固定された板バネ１２８が凹溝８１の摺接面８１ｂと摺接し、他方では、リテーナ２２２，２２３それぞれの内周面が、取付け用ピース１８２の摺接面１８２ｅ及び凹溝８１の摺接面８１ｅと摺接するとともに、リテーナ２２２，２２３の外周側に固定された板バネ２２８が凹溝８１の摺接面８１ｆと摺接することで、第１、第２のリーフシール１２０、２２０がステータ６０に対して嵌め込まれた状態で維持される。   Thus, the mounting piece 182 is shared by the first and second leaf seals 120, 220 that are axially adjacent to each other, and the first and second leaf seals 120, 220, together with the shared mounting piece 182, The groove 60 of the stator 60 is held on the outer peripheral base end side. That is, the inner peripheral surfaces of the retainers 122 and 123 are in sliding contact with the sliding contact surface 81 a of the recessed groove 81 and the sliding contact surface 182 a of the mounting piece 182, and are fixed to the outer peripheral side of the retainers 122 and 123. Is in sliding contact with the sliding contact surface 81b of the recessed groove 81, and on the other hand, the inner peripheral surfaces of the retainers 222 and 223 are in sliding contact with the sliding contact surface 182e of the mounting piece 182 and the sliding contact surface 81e of the recessed groove 81, respectively. A state in which the first and second leaf seals 120 and 220 are fitted into the stator 60 by the leaf spring 228 fixed to the outer peripheral side of the retainers 222 and 223 being in sliding contact with the sliding contact surface 81f of the concave groove 81. Maintained at.

そして、共用の取付け用ピース１８２が、その内周面から径方向外方へ貫通するボルト１８３の締結によってステータ６０に固定されることで、第１、第２のリーフシール１２０、２２０がステータ６０に固定される。これにより、ステータ６０に対するリーフシール１２０、２２０及び取付け用ピース１８２の固定状態が十分に安定して確保できる。   The common mounting piece 182 is fixed to the stator 60 by fastening bolts 183 penetrating radially outward from the inner peripheral surface thereof, so that the first and second leaf seals 120 and 220 are fixed to the stator 60. Fixed to. Thereby, the fixed state of the leaf seals 120 and 220 and the mounting piece 182 with respect to the stator 60 can be secured sufficiently stably.

このような構成にすれば、第１、第２のリーフシール１２０、２２０をステータ６０に取り付けるための取付け用凹溝８１が１つで済み、しかも、回転軸４の軸方向でのリーフシール１２０、２２０同士の間隔は、両者に共用の取付け用ピース１８２が収まる程度で足りる。従って、互いに隣接するリーフシール１２０、２２０同士の間隔を大幅に抑えることができ、これに伴って回転軸４の長さを抑えることが可能になり、流体機械の軸方向への大型化を招くことはない。また、その取付け用凹溝８１をステータ６０に形成するにあたって、その幅がリーフシール１２０、２２０及び取付け用ピース１８２をすべて含む寸法であることから、加工上で十分許容でき、その加工にはまったく支障はない。   With this configuration, only one mounting concave groove 81 for mounting the first and second leaf seals 120 and 220 to the stator 60 is required, and the leaf seal 120 in the axial direction of the rotating shaft 4 is sufficient. , 220 is sufficient to accommodate a common mounting piece 182 for both. Therefore, the interval between the leaf seals 120 and 220 adjacent to each other can be greatly suppressed, and accordingly, the length of the rotating shaft 4 can be suppressed, resulting in an increase in the size of the fluid machine in the axial direction. There is nothing. In addition, when forming the mounting concave groove 81 in the stator 60, the width thereof is a dimension including all of the leaf seals 120, 220 and the mounting piece 182. There is no hindrance.

次に、本発明の第２実施形態について図２を参照しながら説明する。図２は第２実施形態におけるリーフシールを複数段備えた大型流体機械の要部を示す回転軸の軸方向に沿う断面図である。なお、図中で図１と同じ名称で同じ機能を果たす部分には同一の符号を付し、重複する説明は適宜省略する。後述する第３〜第７実施形態においても同様とする。本第２実施形態の特徴は、第１実施形態における取付け用ピース１８２の固定手法を変形した点にある。   Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a cross-sectional view along the axial direction of the rotary shaft showing the main part of a large fluid machine having a plurality of leaf seals according to the second embodiment. In the figure, the same reference numerals are given to the portions having the same names and the same functions as those in FIG. The same applies to third to seventh embodiments described later. The feature of the second embodiment is that the method for fixing the mounting piece 182 in the first embodiment is modified.

つまり本実施形態では、図２に示すように、ステータ６０の凹溝８１の底に形成された補助凹溝８１ｃがあり溝形状になっていて、この補助凹溝８１ｃに取付け用ピース１８２の補助突起１８２ｃが周方向に沿って嵌め込まれることで、そのまま、取付け用ピース１８２が第１、第２のリーフシール１２０、２２０と共にステータ６０に固定される。   That is, in this embodiment, as shown in FIG. 2, there is an auxiliary groove 81 c formed in the bottom of the groove 81 of the stator 60 and has a groove shape, and the auxiliary groove 81 c has an auxiliary piece 182 for assisting the mounting piece 182. By fitting the protrusion 182c along the circumferential direction, the attachment piece 182 is fixed to the stator 60 together with the first and second leaf seals 120 and 220 as they are.

このようにしても、ステータ６０に対するリーフシール１２０、２２０及び取付け用ピース１８２の固定状態が十分に安定して確保できる。しかもこの場合、第１実施形態のようなボルト１８３が一切不要であることから、部品調達や組立工数に関する製造コストの低減に対して有利であるし、流体機械の運転に伴って生じ得るボルト１８３の緩みによる脱落の懸念も一切ないことから、流体機械の性能保障に対しても有利である。   Even in this case, the fixed state of the leaf seals 120 and 220 and the mounting piece 182 to the stator 60 can be secured sufficiently stably. In addition, in this case, since the bolt 183 as in the first embodiment is not required at all, it is advantageous for reduction of manufacturing costs related to parts procurement and assembly man-hours, and the bolt 183 that can be generated with the operation of the fluid machine. Since there is no fear of falling off due to loosening of the fluid, it is advantageous for ensuring the performance of the fluid machine.

次に、本発明の第３実施形態について図３を参照しながら説明する。図３は第３実施形態におけるリーフシールを複数段備えた大型流体機械の要部を示す回転軸の軸方向に沿う断面図である。本第３実施形態の特徴は、第１、第２実施形態に対して部品点数の削減を図った点にある。なお、図３では第２実施形態の変形例を示している。   Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 3 is a cross-sectional view along the axial direction of the rotating shaft showing the main part of a large fluid machine having a plurality of leaf seals according to the third embodiment. The feature of the third embodiment is that the number of parts is reduced compared to the first and second embodiments. FIG. 3 shows a modification of the second embodiment.

つまり本実施形態では、図３に示すように、共用の取付け用ピース１８２と隣接する第１、第２のリーフシール１２０、２２０のうちの高圧側領域の方に位置する第１のリーフシール１２０の構成要素である低圧側のリテーナ１２３を取付け用ピース１８２と一体成形し、そのリテーナ１２３の機能を取付け用ピース１８２に兼用させるようにしている。これにより、部品としてのリテーナ１２３を削減でき、経済性に優位である。   That is, in the present embodiment, as shown in FIG. 3, the first leaf seal 120 located toward the high-pressure side region of the first and second leaf seals 120 and 220 adjacent to the common mounting piece 182. The retainer 123 on the low-pressure side, which is a component of the above, is formed integrally with the mounting piece 182 so that the function of the retainer 123 is also used as the mounting piece 182. Thereby, the retainer 123 as a part can be reduced and it is advantageous in economical efficiency.

次に、本発明の第４実施形態について図４を参照しながら説明する。図４は第４実施形態におけるリーフシールを複数段備えた大型流体機械の要部を示す回転軸の軸方向に沿う断面図である。本第４実施形態の特徴は、第１実施形態における第１、第２のリーフシール１２０、２２０を分割環状のホルダ９０を中間的に介在して、ステータ６０に取り付けた点にある。   Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 4 is a cross-sectional view along the axial direction of the rotary shaft showing the main part of a large-sized fluid machine having a plurality of stages of leaf seals in the fourth embodiment. The feature of the fourth embodiment is that the first and second leaf seals 120 and 220 in the first embodiment are attached to the stator 60 with a split annular holder 90 interposed therebetween.

つまり本実施形態では、図４に示すように、ステータ６０の内周面には、ホルダ９０を取り付けるための周方向に沿う環状の取付け用凹溝９１が形成されている。一方、ホルダ９０の内周面には、上記した第１実施形態と同様に、第１、第２のリーフシール１２０、２２０を取り付けるための周方向に沿う環状の取付け用凹溝８１が１つだけ形成されている。第１、第２のリーフシール１２０、２２０は、共用の取付け用ピース１８２と一体で、ホルダ９０の凹溝８１に周方向に沿って嵌め込まれる。続いて、共用の取付け用ピース１８２が、ホルダ９０の外周面から径方向内方へ貫通するボルト１８３の締結によってホルダ６０に固定されることで、第１、第２のリーフシール１２０、２２０がホルダ６０に十分に安定した状態で固定される。そして、このホルダ９０はステータ６０の凹溝９１に周方向に沿って嵌め込まれる。こうして、ステータ６０に対してリーフシール１２０、２２０及び取付け用ピース１８２が取り付けられる。   That is, in this embodiment, as shown in FIG. 4, an annular mounting groove 91 is formed on the inner peripheral surface of the stator 60 along the circumferential direction for mounting the holder 90. On the other hand, on the inner peripheral surface of the holder 90, there is one annular mounting groove 81 along the circumferential direction for mounting the first and second leaf seals 120 and 220, as in the first embodiment. Only formed. The first and second leaf seals 120 and 220 are integrated with the common mounting piece 182 and are fitted in the concave groove 81 of the holder 90 along the circumferential direction. Subsequently, the common mounting piece 182 is fixed to the holder 60 by fastening bolts 183 penetrating radially inward from the outer peripheral surface of the holder 90, whereby the first and second leaf seals 120, 220 are secured. It is fixed to the holder 60 in a sufficiently stable state. The holder 90 is fitted in the concave groove 91 of the stator 60 along the circumferential direction. Thus, the leaf seals 120 and 220 and the mounting piece 182 are attached to the stator 60.

このような構成にすれば、第１、第２のリーフシール１２０、２２０がホルダ９０を介在してステータ６０に取り付けられるわけであるが、第１実施形態と同様、それらのリーフシール１２０、２２０をホルダ９０に取り付けるための取付け用凹溝８１が１つで済み、しかも、回転軸４の軸方向でのリーフシール１２０、２２０同士の間隔は、両者に共用の取付け用ピース１８２が収まる程度で足りる。従って、互いに隣接するリーフシール１２０、２２０同士の間隔を大幅に抑えることができ、これに伴って回転軸４の長さを抑えることが可能になり、流体機械の軸方向への大型化を招くことはない。また、その取付け用凹溝８１をホルダ９０に形成するにあたって、その幅がリーフシール１２０、２２０及び取付け用ピース１８２をすべて含む寸法であることから、加工上で十分許容でき、その加工にはまったく支障はない。   With this configuration, the first and second leaf seals 120 and 220 are attached to the stator 60 with the holder 90 interposed therebetween. However, as in the first embodiment, these leaf seals 120 and 220 are attached. The mounting groove 81 for attaching the holder 90 to the holder 90 is sufficient, and the spacing between the leaf seals 120 and 220 in the axial direction of the rotating shaft 4 is such that the common mounting piece 182 fits in both. It ’s enough. Therefore, the interval between the leaf seals 120 and 220 adjacent to each other can be greatly suppressed, and accordingly, the length of the rotating shaft 4 can be suppressed, resulting in an increase in the size of the fluid machine in the axial direction. There is nothing. Further, when the mounting concave groove 81 is formed in the holder 90, the width thereof is a dimension including all of the leaf seals 120 and 220 and the mounting piece 182. There is no hindrance.

特に本実施形態では、取付け用ピース１８２をホルダ９０に締結するボルト１８３が、ステータ６０の凹溝８１内に収容された格好になるため、例え大きく緩んだとしても、脱落に至ることはない。なお、上記した第１実施形態と同様にして、取付け用ピース１８２の内周面から径方向外方へ貫通するボルト１８３により、ホルダ９０に対して取付け用ピース１８２を締結しても構わない。   In particular, in the present embodiment, the bolt 183 that fastens the mounting piece 182 to the holder 90 is housed in the concave groove 81 of the stator 60, so that even if the bolt 183 is loosened greatly, it does not fall off. In the same manner as in the first embodiment described above, the mounting piece 182 may be fastened to the holder 90 with a bolt 183 that penetrates radially outward from the inner peripheral surface of the mounting piece 182.

次に、本発明の第５実施形態について図５を参照しながら説明する。図５は第５実施形態におけるリーフシールを複数段備えた大型流体機械の要部を示す回転軸の軸方向に沿う断面図である。本第５実施形態の特徴は、第４実施形態における取付け用ピース１８２のボルト１８３による締結手法を変形した点にある。   Next, a fifth embodiment of the present invention will be described with reference to FIG. FIG. 5 is a cross-sectional view along the axial direction of the rotary shaft showing the main part of a large fluid machine having a plurality of leaf seals according to the fifth embodiment. The feature of the fifth embodiment is that the fastening method using the bolt 183 of the mounting piece 182 in the fourth embodiment is modified.

つまり本実施形態では、図５に示すように、ホルダ９０の凹溝８１に嵌め込まれた取付け用ピース１８２が、ホルダ９０の側面から回転軸４の軸方向に沿って貫通するボルト１８３の締結によってホルダ６０に固定される。   That is, in this embodiment, as shown in FIG. 5, the mounting piece 182 fitted in the concave groove 81 of the holder 90 is fastened by a bolt 183 that penetrates from the side surface of the holder 90 along the axial direction of the rotary shaft 4. It is fixed to the holder 60.

このようにしても、ホルダ９０に対するリーフシール１２０、２２０及び取付け用ピース１８２の固定状態が十分に安定して確保できる。しかもこの場合、ボルト１８３の負担できる許容強度を増すべくその径を太くすることが可能であることから、その所要本数を少なくしても、ホルダ９０に対しての取付け用ピース１８２の安定的な固定を十分に確保できる。第４実施形態のような径方向でのボルト１８３による締結では、回転軸４の軸方向でのスペースの制約から、ボルト１８３の径の拡大は制限されるからである。   Even in this case, the fixed state of the leaf seals 120 and 220 and the mounting piece 182 to the holder 90 can be secured sufficiently stably. In this case, the diameter of the bolt 183 can be increased so as to increase the allowable strength that the bolt 183 can bear. Therefore, even if the required number is reduced, the mounting piece 182 for the holder 90 can be stably mounted. Fixing can be secured sufficiently. This is because in the fastening with the bolt 183 in the radial direction as in the fourth embodiment, the expansion of the diameter of the bolt 183 is limited due to the space restriction in the axial direction of the rotary shaft 4.

次に、本発明の第６、第７実施形態について図６、図７に示す。図６、図７はそれぞれ第６、第７実施形態におけるリーフシールを複数段備えた大型流体機械の要部を示す回転軸の軸方向に沿う断面図である。第６実施形態では、図６に示すように、第１実施形態に対しての第２実施形態の変形態様と同様にして、第４、第５実施形態における取付け用ピース１８２の固定手法を変形している。第７実施形態では、図７に示すように、第１、第２実施形態に対しての第３実施形態の変形態様と同様にして、第４、第５実施形態に対しての部品点数の削減を図っている。   Next, FIGS. 6 and 7 show sixth and seventh embodiments of the present invention. 6 and 7 are cross-sectional views along the axial direction of the rotary shaft showing the main part of a large-sized fluid machine provided with a plurality of leaf seals in the sixth and seventh embodiments, respectively. In the sixth embodiment, as shown in FIG. 6, the fixing method of the mounting piece 182 in the fourth and fifth embodiments is modified in the same manner as the modification of the second embodiment with respect to the first embodiment. is doing. In the seventh embodiment, as shown in FIG. 7, the number of parts for the fourth and fifth embodiments is the same as the modification of the third embodiment for the first and second embodiments. We are trying to reduce it.

なお、上記した各実施形態では、リーフシール２０を２段に設置した構成について説明したが、３段以上であってもよい。その場合、互いに隣接するリーフシール２０同士の間にそれぞれ取付け用ピース１８２を備えれば足りる。   In each of the above-described embodiments, the configuration in which the leaf seals 20 are installed in two stages has been described, but three or more stages may be used. In that case, it is only necessary to provide the attachment pieces 182 between the leaf seals 20 adjacent to each other.

その他本発明は上記の各実施形態に限定されず、本発明の趣旨を逸脱しない範囲で、種々の変更が可能である。例えば、図８に示すガスタービンにリーフシールを採用しているものを例示しているが、それに限定されるものではなく、蒸気タービン、圧縮機、水車、冷凍機、ポンプ等の大型流体機械のように、軸の回転と作動流体の流動の関係でエネルギーを仕事に変換するものに広く採用することができる。また、回転軸の周面に沿った軸方向での作動流体の流動を抑えるためにも用いることができる。   In addition, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, although the thing which employ | adopted the leaf seal is illustrated in the gas turbine shown in FIG. 8, it is not limited to it, Large-sized fluid machinery, such as a steam turbine, a compressor, a water turbine, a refrigerator, a pump, is shown. As described above, it can be widely applied to those that convert energy into work due to the relationship between the rotation of the shaft and the flow of the working fluid. It can also be used to suppress the flow of the working fluid in the axial direction along the peripheral surface of the rotating shaft.

本発明は、大型流体機械の回転軸に対しての軸シール機構として有用である。   The present invention is useful as a shaft seal mechanism for a rotating shaft of a large fluid machine.

本発明の第１実施形態におけるリーフシールを複数段備えた大型流体機械の要部を示す回転軸の軸方向に沿う断面図である。It is sectional drawing which follows the axial direction of the rotating shaft which shows the principal part of the large sized fluid machine provided with the leaf seal in multiple steps in 1st Embodiment of this invention. 本発明の第２実施形態におけるリーフシールを複数段備えた大型流体機械の要部を示す回転軸の軸方向に沿う断面図である。It is sectional drawing which follows the axial direction of the rotating shaft which shows the principal part of the large sized fluid machine provided with the leaf seal in 2nd Embodiment of this invention. 本発明の第３実施形態におけるリーフシールを複数段備えた大型流体機械の要部を示す回転軸の軸方向に沿う断面図である。It is sectional drawing in alignment with the axial direction of the rotating shaft which shows the principal part of the large sized fluid machine provided with the leaf seal in 3rd Embodiment of this invention. 本発明の第４実施形態におけるリーフシールを複数段備えた大型流体機械の要部を示す回転軸の軸方向に沿う断面図である。It is sectional drawing which follows the axial direction of the rotating shaft which shows the principal part of the large sized fluid machine provided with the multi-stage leaf seal in 4th Embodiment of this invention. 本発明の第５実施形態におけるリーフシールを複数段備えた大型流体機械の要部を示す回転軸の軸方向に沿う断面図である。It is sectional drawing in alignment with the axial direction of the rotating shaft which shows the principal part of the large sized fluid machine provided with the leaf seal in 5th Embodiment of this invention. 本発明の第６実施形態におけるリーフシールを複数段備えた大型流体機械の要部を示す回転軸の軸方向に沿う断面図である。It is sectional drawing which follows the axial direction of the rotating shaft which shows the principal part of the large sized fluid machine provided with the leaf seal in 6th Embodiment of this invention. 本発明の第７実施形態におけるリーフシールを複数段備えた大型流体機械の要部を示す回転軸の軸方向に沿う断面図である。It is sectional drawing which follows the axial direction of the rotating shaft which shows the principal part of the large sized fluid machine provided with the leaf seal in 7th Embodiment of this invention. 従来一般のリーフシールを備えた大型流体機械の一例であるガスタービンの構成を示す概略図である。It is the schematic which shows the structure of the gas turbine which is an example of the large sized fluid machine provided with the conventional general leaf seal. 従来一般のリーフシールの基本構成を示す斜視図である。It is a perspective view which shows the basic composition of the conventional general leaf seal. 従来一般のリーフシールを備えた大型流体機械の要部を示す回転軸の軸方向に沿う断面図である。It is sectional drawing which follows the axial direction of the rotating shaft which shows the principal part of the large sized fluid machine provided with the conventional general leaf seal. 従来一般のリーフシールの基本構成を示す回転軸の周方向に沿う側面図及び断面図である。It is the side view and sectional drawing which follow the circumferential direction of the rotating shaft which shows the basic composition of the conventional general leaf seal. 従来一般のリーフシールの構成要素である薄板の側面図である。It is a side view of the thin plate which is a component of the conventional general leaf seal. 従来一般のリーフシールの作用を説明するための模式図である。It is a schematic diagram for demonstrating the effect | action of the conventional general leaf seal. 従来一般のリーフシールの作用を説明するための模式図である。It is a schematic diagram for demonstrating the effect | action of the conventional general leaf seal. 従来一般のリーフシールを環状に配置した状態を示す平面図である。It is a top view which shows the state which has arrange | positioned the conventional general leaf seal in cyclic | annular form. 従来におけるリーフシールを複数段備えた大型流体機械の要部を示す回転軸の軸方向に沿う断面図である。It is sectional drawing in alignment with the axial direction of the rotating shaft which shows the principal part of the large sized fluid machine provided with the conventional leaf seal in multiple steps. 従来におけるリーフシールを複数段備えた他の大型流体機械の要部を示す回転軸の軸方向に沿う断面図である。It is sectional drawing in alignment with the axial direction of the rotating shaft which shows the principal part of the other large sized fluid machine provided with the multi-stage leaf seal in the past.

符号の説明Explanation of symbols

４ 回転軸
２０，１２０，２２０ リーフシール
２１，１２１，２２１ 薄板
２２，２３，１２２，１２３，２２２，２２３ リテーナ
２４，１２４，２２４ 高圧側側板
２５，１２５，２２５ 低圧側側板
２８，１２８，２２８ 板バネ
６０ ステータ
６１，８１ 取付け用凹溝
９０ ホルダ
９１ 取付け用凹溝
１８２ 取付け用ピース
１８３ ボルト 4 Rotating shaft 20, 120, 220 Leaf seal 21, 121, 221 Thin plate 22, 23, 122, 123, 222, 223 Retainer 24, 124, 224 High pressure side plate 25, 125, 225 Low pressure side plate 28, 128, 228 Plate Spring 60 Stator 61, 81 Mounting groove 90 Holder 91 Mounting groove 182 Mounting piece 183 Bolt

Claims (8)

回転軸の周面とこの回転軸に同軸状で静止した静止部材の内周面との隙間においての高圧側から低圧側への作動流体の漏れを抑える軸シール機構であって、
前記回転軸の軸方向に一定幅を有し、各々が前記回転軸の周方向へ互いに微小隙間を隔てながら前記回転軸の周面に対して鋭角に積み重ねられつつ、各々の内周端が回転停止時の前記回転軸の周面に接触する可撓性のある多数の薄板より成る環状の薄板群と、この薄板群における軸方向での両側のうちの高圧側に位置する一側に当接し、前記回転軸の径よりも所定量大きい内径を有する環状の高圧側側板と、前記薄板群における軸方向での両側のうちの低圧側に位置する他側に当接し、前記高圧側側板の内径よりも所定量大きい内径を有する環状の低圧側側板と、前記薄板群、前記高圧側側板、及び前記低圧側側板をこれらの外周部で一体に保持する環状の保持部材と、より成る周方向に分割可能な軸シール部材を、前記静止部材に対して軸方向へ複数段取り付けた軸シール機構において、
前記静止部材の内周面に周方向に沿う取付け用溝が形成されていて、互いに隣接する前記各段の前記各軸シール部材同士の間に共用の取付け用部材を備えており、
前記各シール部材及び前記各取付け用部材は、一体で前記取付け用溝に周方向に沿って嵌め込まれて前記静止部材に固定されたことを特徴とする軸シール機構。 A shaft seal mechanism that suppresses leakage of working fluid from the high pressure side to the low pressure side in the gap between the peripheral surface of the rotating shaft and the inner peripheral surface of a stationary member that is coaxial and stationary with respect to the rotating shaft,
Each inner peripheral end rotates while having a certain width in the axial direction of the rotating shaft and being stacked at an acute angle with respect to the peripheral surface of the rotating shaft, with each having a small gap in the circumferential direction of the rotating shaft. An annular thin plate group consisting of a large number of flexible thin plates that come into contact with the peripheral surface of the rotating shaft when stopped, and one side located on the high pressure side of both sides of the thin plate group in the axial direction. An annular high-pressure side plate having an inner diameter larger than the diameter of the rotary shaft by contact with the other side located on the low-pressure side of both sides of the thin plate group in the axial direction, and the inner diameter of the high-pressure side plate An annular low-pressure side plate having an inner diameter larger than a predetermined amount, an annular holding member that integrally holds the thin plate group, the high-pressure side plate, and the low-pressure side plate at their outer peripheral portions, in a circumferential direction. The separable shaft seal member is pivoted with respect to the stationary member. In the shaft sealing mechanism with several setup to direction,
A mounting groove along the circumferential direction is formed on the inner peripheral surface of the stationary member, and a common mounting member is provided between the shaft seal members of the adjacent stages.
The shaft seal mechanism, wherein the seal members and the attachment members are integrally fitted in the attachment grooves along the circumferential direction and fixed to the stationary member. 前記各取付け用部材は、前記静止部材へ径方向に貫通するボルトで締結されて固定されたことを特徴とする請求項１に記載の軸シール機構。   2. The shaft seal mechanism according to claim 1, wherein each of the attachment members is fastened and fixed to the stationary member by a bolt that penetrates in a radial direction. 前記各取付け用部材は、この外周面に周方向に沿って形成された補助突起が、前記取付け用溝の底に周方向に沿って形成された補助溝に嵌合して固定されたことを特徴とする請求項１に記載の軸シール機構。   Each of the mounting members has an auxiliary projection formed on the outer peripheral surface along the circumferential direction fitted and fixed to an auxiliary groove formed on the bottom of the mounting groove along the circumferential direction. The shaft seal mechanism according to claim 1, wherein 回転軸の周面とこの回転軸に同軸状で静止した静止部材の内周面との隙間においての高圧側から低圧側への作動流体の漏れを抑える軸シール機構であって、
前記回転軸の軸方向に一定幅を有し、各々が前記回転軸の周方向へ互いに微小隙間を隔てながら前記回転軸の周面に対して鋭角に積み重ねられつつ、各々の内周端が回転停止時の前記回転軸の周面に接触する可撓性のある多数の薄板より成る環状の薄板群と、この薄板群における軸方向での両側のうちの高圧側に位置する一側に当接し、前記回転軸の径よりも所定量大きい内径を有する環状の高圧側側板と、前記薄板群における軸方向での両側のうちの低圧側に位置する他側に当接し、前記高圧側側板の内径よりも所定量大きい内径を有する環状の低圧側側板と、前記薄板群、前記高圧側側板、及び前記低圧側側板をこれらの外周部で一体に保持する環状の保持部材と、より成る周方向に分割可能な軸シール部材を、前記静止部材に対して軸方向へ複数段取り付けた軸シール機構において、
前記静止部材の内周面に周方向に沿う取付け用溝が形成されていて、内周面に周方向に沿う中間取付け用溝が形成された中間取付け用部材と、互いに隣接する前記各段の前記各軸シール部材同士の間に共用の取付け用部材とを備えており、
前記各シール部材及び前記各取付け用部材は、一体で前記中間取付け用溝に周方向に沿って嵌め込まれて前記中間取付け用部材に固定され、前記各シール部材及び前記各取付け用部材が固定された前記中間取付け用部材は、前記取付け用溝に周方向に沿って嵌め込まれて前記静止部材に固定されたことを特徴とする軸シール機構。 A shaft seal mechanism that suppresses leakage of working fluid from the high pressure side to the low pressure side in the gap between the peripheral surface of the rotating shaft and the inner peripheral surface of a stationary member that is coaxial and stationary with respect to the rotating shaft,
Each inner peripheral end rotates while having a certain width in the axial direction of the rotating shaft and being stacked at an acute angle with respect to the peripheral surface of the rotating shaft, with each having a small gap in the circumferential direction of the rotating shaft. An annular thin plate group consisting of a large number of flexible thin plates that come into contact with the peripheral surface of the rotating shaft when stopped, and one side located on the high pressure side of both sides of the thin plate group in the axial direction. An annular high-pressure side plate having an inner diameter larger than the diameter of the rotary shaft by contact with the other side located on the low-pressure side of both sides of the thin plate group in the axial direction, and the inner diameter of the high-pressure side plate An annular low-pressure side plate having an inner diameter larger than a predetermined amount, an annular holding member that integrally holds the thin plate group, the high-pressure side plate, and the low-pressure side plate at their outer peripheral portions, in a circumferential direction. The separable shaft seal member is pivoted with respect to the stationary member. In the shaft sealing mechanism with several setup to direction,
A mounting groove is formed on the inner peripheral surface of the stationary member along the circumferential direction, and the intermediate mounting member is formed on the inner peripheral surface with an intermediate mounting groove along the circumferential direction. A common mounting member is provided between the shaft seal members,
The seal members and the attachment members are integrally fitted in the intermediate attachment grooves along the circumferential direction and fixed to the intermediate attachment members, and the seal members and the attachment members are fixed. The intermediate mounting member is fitted in the mounting groove along the circumferential direction and fixed to the stationary member. 前記各取付け用部材は、前記中間取付け用部材を径方向に貫通するボルトで締結されて固定されたことを特徴とする請求項４に記載の軸シール機構。   The shaft seal mechanism according to claim 4, wherein each of the mounting members is fastened and fixed by a bolt that penetrates the intermediate mounting member in a radial direction. 前記各取付け用部材は、前記中間取付け用部材を軸方向に貫通するボルトで締結されて固定されたことを特徴とする請求項４に記載の軸シール機構。   The shaft seal mechanism according to claim 4, wherein each of the mounting members is fastened and fixed by a bolt that penetrates the intermediate mounting member in the axial direction. 前記各取付け用部材は、この外周面に周方向に沿って形成された補助突起が、前記中間取付け用溝の底に周方向に沿って形成された中間補助溝に嵌合して固定されたことを特徴とする請求項４に記載の軸シール機構。   Each of the mounting members is fixed by fitting an auxiliary projection formed on the outer peripheral surface along the circumferential direction into an intermediate auxiliary groove formed along the circumferential direction on the bottom of the intermediate mounting groove. The shaft seal mechanism according to claim 4, wherein 前記各取付け用部材は、互いに隣接する前記各段の前記各シール部材を構成する前記保持部材の一部を兼ねることを特徴とする請求項１から７のいずれかに記載の軸シール機構。   8. The shaft seal mechanism according to claim 1, wherein each of the attachment members also serves as a part of the holding member that constitutes each of the seal members of the respective stages adjacent to each other.

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