JP5519346B2 - Dry contact mechanical seal - Google Patents
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- JP5519346B2 JP5519346B2 JP2010059109A JP2010059109A JP5519346B2 JP 5519346 B2 JP5519346 B2 JP 5519346B2 JP 2010059109 A JP2010059109 A JP 2010059109A JP 2010059109 A JP2010059109 A JP 2010059109A JP 5519346 B2 JP5519346 B2 JP 5519346B2
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本発明は、医薬，食品，化学品，半導体等の分野で使用される回転機器であってガスを扱う攪拌機等の回転機器に軸封装置として装備されるドライコンタクトメカニカルシールに関するものである。 The present invention relates to a dry contact mechanical seal which is a rotary device used in the fields of medicine, food, chemicals, semiconductors and the like and is installed as a shaft seal device in a rotary device such as a stirrer for handling gas.
従来のドライコンタクトメカニカルシールとして、シールケースに固定された静止密封環と回転軸に軸線方向移動可能に保持された回転密封環との対向端面である密封端面の相対回転摺接作用により機内ガス領域（高圧ガス領域）と機外ガス領域（低圧ガス領域である大気領域）とをシールするように構成されたものが周知である(例えば、特許文献１を参照)。 As a conventional dry contact mechanical seal, the in-machine gas region is caused by the relative rotational sliding contact of the sealing end surface, which is the opposite end surface of the stationary sealing ring fixed to the sealing case and the rotating sealing ring held axially movable on the rotating shaft. It is well known that it is configured to seal the (high pressure gas region) and the external gas region (atmosphere region which is a low pressure gas region) (see, for example, Patent Document 1).
このようなドライコンタクトメカニカルシールにあっては、両密封環の密封端面が圧接状態で相対回転されるが、その相対回転摺接部分が液体潤滑されないドライ雰囲気（ガス雰囲気）で運転されることから、両密封環の相対回転摺接部分（密封端面）が摩擦により発熱し、密封環の温度上昇による異常摩耗や熱歪による密封端面の変形による多量漏れを生じる等、良好なメカニカルシール機能を発揮できない虞れがある。また、このような多量漏れを生じない場合にも、密封端面間からの漏れを完全に阻止することはできず、機内ガスの漏れを許容しない条件下においては使用できないものであった。 In such a dry contact mechanical seal, the sealing end faces of both sealing rings are relatively rotated in a pressure contact state, but the relative rotational sliding contact portion is operated in a dry atmosphere (gas atmosphere) in which liquid lubrication is not performed. The relative rotational sliding contact portion (sealed end face) of both seal rings generates heat due to friction, and exhibits excellent mechanical seal functions such as abnormal wear due to temperature rise of the seal ring and large amount of leakage due to deformation of the sealed end face due to thermal strain. There is a possibility that it cannot be done. Further, even when such a large amount of leakage does not occur, leakage from between the sealed end faces cannot be completely prevented, and it cannot be used under conditions that do not allow leakage of in-machine gas.
本発明は、上記のような問題を生じることなく、良好なシール機能を発揮しうるドライコンタクトメカニカルシールを提供することを目的とするものである。 An object of the present invention is to provide a dry contact mechanical seal capable of exhibiting a good sealing function without causing the above problems.
本発明は、シールケースに固定された静止密封環と回転軸に軸線方向移動可能に保持され且つスプリングにより静止密封環へと押圧附勢された回転密封環との対向端面たる密封端面の相対回転摺接作用によりガス領域である当該相対回転摺接部分の内周側領域と外周側領域とを遮蔽シールするように構成されたドライコンタクトメカニカルシールにおいて、上記の目的を達成すべく、特に、回転軸を先端円筒部とこれより大径の中間円筒部とこれより大径の基端円筒部とからなる円筒構造のスプリングリテーナを嵌合固定したものとし、回転密封環は、スプリングリテーナの先端円筒部に軸線方向に摺動自在に嵌合された本体部とスプリングリテーナの中間円筒部に遊嵌された二次シール部とからなる円筒体であって、二次シール部とスプリングリテーナの先端円筒部との間にＯリングを介在させた二次シール状態で回転軸に軸線方向移動可能に嵌合保持されており、内径が回転密封環の密封端面の内径より大きく且つ外径が回転密封環の密封端面の外径より小さい静止密封環の密封端面に、回転密封環の密封端面により閉塞された環状のバリア空間を凹設すると共に、シールケース及び静止密封環に、これらを貫通してバリア空間にバリア流体を供給する一連のバリア流体供給路を形成してあり、静止密封環の内外径、回転密封環の二次シール部の内径及びスプリングリテーナの先端円筒部の外径並びにバリア空間内のバリア流体圧力を、前記内周側領域が高圧ガス領域であり且つ前記外周側領域が低圧ガス領域である場合及び当該外周側領域が高圧ガス領域であり且つ当該内周側領域が低圧ガス領域である場合の何れにおいても当該バリア流体圧力を高圧ガス領域の圧力より０．０５〜０．３ＭＰａ高圧となるように保持すると共にバリア空間内のバリア流体圧力により回転密封環を静止密封環から離間する方向へと押圧する開力がスプリングの附勢力及び前記ガス領域の流体圧力により回転密封環を静止密封環へと押圧する閉力とバランスされて両密封端面が接触面圧を生じない状態で相対回転摺接されるように、設定しておくことを提案するものである。 The present invention relates to a relative rotation of a sealing end face as an opposite end face between a stationary sealing ring fixed to a sealing case and a rotating sealing ring which is held axially movable on a rotary shaft and pressed and biased to a stationary sealing ring by a spring. In the dry contact mechanical seal configured to shield and seal the inner peripheral side region and the outer peripheral side region of the relative rotational sliding contact portion which is the gas region by the sliding contact action, in order to achieve the above-mentioned purpose, in particular, the rotation A shaft-type spring retainer consisting of a tip cylindrical part, an intermediate cylindrical part having a larger diameter than this, and a proximal cylindrical part having a larger diameter than this is fitted and fixed, and the rotary seal ring is the tip cylindrical part of the spring retainer. A cylindrical body comprising a main body portion slidably fitted in the axial direction and a secondary seal portion loosely fitted to an intermediate cylindrical portion of the spring retainer, the secondary seal portion and the spring It is fitted and held on the rotary shaft so that it can move in the axial direction in a secondary seal state with an O-ring interposed between the end cylindrical part of the grinder and the inner diameter is larger than the inner diameter of the sealing end face of the rotary seal ring and the outer diameter. An annular barrier space closed by the sealing end surface of the rotary sealing ring is recessed in the sealing end surface of the stationary sealing ring that is smaller than the outer diameter of the sealing end surface of the rotating sealing ring. A series of barrier fluid supply passages that pass through and supply barrier fluid to the barrier space are formed. The inner and outer diameters of the stationary seal ring, the inner diameter of the secondary seal portion of the rotary seal ring, and the outer diameter of the tip cylindrical portion of the spring retainer And the barrier fluid pressure in the barrier space when the inner peripheral region is a high pressure gas region and the outer peripheral region is a low pressure gas region, and when the outer peripheral region is a high pressure gas region and the inner periphery The rotary seal ring by the barrier fluid pressure in the barrier space together with region to hold the barrier fluid pressure in either case is a low pressure gas region so that 0.05~0.3MPa pressure than the pressure of the high-pressure gas region The opening force that pushes away from the stationary seal ring is balanced by the biasing force of the spring and the closing force that pushes the rotary seal ring to the stationary seal ring by the fluid pressure in the gas region, so that both sealing end faces are in contact surface pressure. It is proposed to set the relative rotational sliding contact in a state that does not cause the problem.
かかるドライコンタクトメカニカルシールの好ましい実施の形態にあっては、バリア流体の消費量を可及的に減じつつバリア空間内を上記した圧力に保持しておくためにバリア流体供給路に絞り器を配設しておくことが好ましく、当該絞り器はシールケースに形成されたバリア流体供給路部分に配設しておくことがより好ましい。また、バリア流体としては窒素ガス等の気体や水等の液体を使用することができるが、気体を使用する場合には、当該バリア空間内の圧力をこれが高圧ガス領域の圧力より０．０５〜０．１ＭＰａ高くなるように保持させておくことが好ましい。 In a preferred embodiment of such a dry contact mechanical seal, a restrictor is provided in the barrier fluid supply path in order to keep the pressure in the barrier space at the above-mentioned pressure while reducing the consumption of the barrier fluid as much as possible. It is preferable that the restrictor is provided, and it is more preferable that the restrictor is provided in a barrier fluid supply path portion formed in the seal case. In addition, a gas such as nitrogen gas or a liquid such as water can be used as the barrier fluid. However, when using a gas, the pressure in the barrier space is 0.05 to It is preferable to keep the pressure higher by 0.1 MPa .
本発明のドライコンタクトメカニカルシールは、両密封環の対向端面である密封端面が接触面圧を生じない状態で相対回転摺接するように構成されたものであるから、ドライ雰囲気で運転される端面接触形メカニカルシールに宿命的な問題（摩擦熱による歪の発生や異常摩耗）を排除することができ、さらにバリア空間に高圧ガス領域より高圧のバリア流体を封入させることにより、密封端面間からのガス漏れを確実に阻止して、完璧なシール機能を発揮することができるものである。しかも、バリア空間からのバリア流体の流出量（消費量）が少ないため、バリア流体を使用することによるランニングコスト等の経済的負担が小さい。 Since the dry contact mechanical seal of the present invention is configured so that the sealing end face which is the opposite end face of both sealing rings is in relative rotational sliding contact with no contact surface pressure, it is end face contact operated in a dry atmosphere. It is possible to eliminate fatal problems (strain generation due to frictional heat and abnormal wear) in the mechanical seal, and by sealing the barrier space with a higher-pressure barrier fluid than the high-pressure gas region, Leakage can be reliably prevented and a perfect sealing function can be exhibited. In addition, since the outflow amount (consumption amount) of the barrier fluid from the barrier space is small, the economic burden such as running cost due to the use of the barrier fluid is small.
以下、本発明を実施するための形態を図１〜図３に基づいて具体的に説明する。図１は本発明に係るドライコンタクトメカニカルシールの一例を示す縦断正面図であり、図２は当該メカニカルシールの縦断側面図であり、図３は図１の要部を拡大して示す詳細図である。 Hereinafter, the form for implementing this invention is demonstrated concretely based on FIGS. 1-3. FIG. 1 is a longitudinal front view showing an example of a dry contact mechanical seal according to the present invention, FIG. 2 is a longitudinal side view of the mechanical seal, and FIG. 3 is a detailed view showing an enlarged main part of FIG. is there.
この実施の形態におけるドライコンタクトメカニカルシールは、医薬，食品，化学，半導体等の分野において使用される攪拌機等の回転機器であってガスを扱う回転機器の軸封手段として使用されるものであり、本発明に従って、次のように構成されている。 The dry contact mechanical seal in this embodiment is a rotating device such as a stirrer used in the fields of medicine, food, chemistry, semiconductor, etc., and is used as a shaft sealing means of a rotating device that handles gas, According to the present invention, it is configured as follows.
すなわち、図１に示すドライコンタクトメカニカルシールは、回転機器のハウジング１にシールケース２を取り付け、このシールケース２に静止密封環３を固定し、静止密封環３を同心状に貫通する当該回転機器の回転軸（攪拌軸等）４に回転密封環５をＯリング６を介して軸線方向移動可能に嵌合保持し、回転密封環５をこれと回転軸４との間に介装したスプリング７により静止密封環３へと押圧附勢して、両密封環３，５の対向端面たる密封端面３ａ，５ａの相対回転摺接作用により、当該相対回転摺接部分３ａ，５ａの内周側領域である機内ガス領域Ａとその外周側領域である機外ガス領域Ｂとを遮蔽シールするように構成された端面接触形メカニカルシールである。この例では、機外ガス領域Ｂは大気領域である低圧ガス領域であり、機内ガス領域Ａは大気圧より高い高圧ガス領域である。なお、以下において使用する圧力はすべてゲージ圧力を意味するものとする。 That is, in the dry contact mechanical seal shown in FIG. 1, a seal case 2 is attached to a housing 1 of a rotary device, a stationary seal ring 3 is fixed to the seal case 2, and the rotary device penetrates the stationary seal ring 3 concentrically. A rotary seal ring 5 is fitted and held on the rotary shaft 4 (stirring shaft or the like) 4 through an O-ring 6 so as to be movable in the axial direction, and the rotary seal ring 5 is interposed between the rotary shaft 4 and the spring 7. The inner peripheral region of the relative rotational sliding contact portions 3a and 5a is pressed and urged to the stationary sealing ring 3 by the relative rotational sliding contact action of the sealing end surfaces 3a and 5a which are the opposite end surfaces of the both sealing rings 3 and 5. Is an end surface contact type mechanical seal configured to shield and seal the in-machine gas region A and the out-of-machine gas region B which is the outer peripheral side region. In this example, the out-of-machine gas region B is a low-pressure gas region that is an atmospheric region, and the in-machine gas region A is a high-pressure gas region that is higher than atmospheric pressure. In addition, the pressure used below shall mean a gauge pressure.
シールケース２は、図１及び図２に示す如く、ハウジング１にその軸封部端面１ａに衝合する状態で取り付けられた円筒体であり、ステンレス鋼等の金属材（例えば、ＳＵＳ３０４等）で構成されている。 As shown in FIGS. 1 and 2, the seal case 2 is a cylindrical body attached to the housing 1 so as to abut against the end face 1a of the shaft seal portion, and is made of a metal material such as stainless steel (for example, SUS304). It is configured.
静止密封環３は、図１及び図２に示す如く、シール条件に応じて選定された適宜の材料（カーボン，炭化珪素等のセラミックス，ポリテトラフルオロエチレン（ＰＴＦＥ）を主成分とする複合材，超硬合金等）で構成された円環状体であり、シールケース２の内周部に一対のＯリング８，９を介して同心状に内嵌固定されている。静止密封環３の先端面は、軸線に直交する円環状の平滑平面である密封端面（以下「静止側密封端面」という）３ａに構成されている。この静止側密封端面３ａの内外径Ｄ１，Ｄ２は、図３に示す如く、その内径Ｄ１が回転密封環５の密封端面（以下「回転側密封端面」という）５ａの内径より大きく且つその外径Ｄ２が回転側密封端面５ａの外径より小さくなるように、設定されている。 As shown in FIGS. 1 and 2, the stationary seal ring 3 is made of an appropriate material selected according to the sealing conditions (carbon, ceramics such as silicon carbide, composite material mainly composed of polytetrafluoroethylene (PTFE), An annular body made of cemented carbide or the like, and is concentrically fitted and fixed to the inner peripheral portion of the seal case 2 via a pair of O-rings 8 and 9. The distal end surface of the stationary seal ring 3 is configured as a sealed end surface (hereinafter referred to as “stationary side sealed end surface”) 3 a which is an annular smooth plane orthogonal to the axis. As shown in FIG. 3, the inner and outer diameters D1 and D2 of the stationary side sealing end surface 3a have an inner diameter D1 larger than the inner diameter of the sealing end surface (hereinafter referred to as “rotation side sealing end surface”) 5a of the rotary sealing ring 5 and its outer diameter. D2 is set so as to be smaller than the outer diameter of the rotation-side sealing end surface 5a.
回転軸４は、図１及び図２に示す如く、ハウジング１から機外領域Ｂへと延びてシールケース２及び静止密封環３を同心状に貫通する軸本体１１とこれに嵌合固定されたスプリングリテーナ１２とからなる。スプリングリテーナ１２は、ステンレス鋼等の金属材（例えば、ＳＵＳ３１６等）で構成されたもので、図１及び図２に示す如く、先端円筒部１２ａとこれより大径の中間円筒部１２ｂとこれより大径の基端円筒部１２ｃとからなる円筒体であり、基端円筒部１２ｃに螺合させた適当数のセットスクリュー１３(図２参照)を締め付けることにより、静止密封環３より機外ガス領域側に配して軸本体１１に固定されている。 As shown in FIGS. 1 and 2, the rotary shaft 4 is fitted and fixed to a shaft main body 11 that extends from the housing 1 to the outside region B and passes through the seal case 2 and the stationary seal ring 3 concentrically. It consists of a spring retainer 12. The spring retainer 12 is made of a metal material such as stainless steel (for example, SUS316). As shown in FIGS. 1 and 2, the tip cylindrical portion 12a and the intermediate cylindrical portion 12b having a larger diameter than the leading cylindrical portion 12a are used. It is a cylindrical body composed of a large-diameter base end cylindrical part 12c, and by tightening an appropriate number of set screws 13 (see FIG. 2) screwed into the base end cylindrical part 12c, the gas outside the machine is removed from the stationary sealing ring 3. Arranged on the region side and fixed to the shaft body 11.
回転密封環５は、図１及び図２に示す如く、スプリングリテーナ１２の先端円筒部１２ａに軸線方向に摺動自在に嵌合された本体部５ｂとスプリングリテーナ１２の中間円筒部１２ｂに遊嵌された二次シール部５ｃとからなる円筒体であり、二次シール部５ｃとスプリングリテーナ１２の先端円筒部１２ａとの間にＯリング６を介在させた二次シール状態で回転軸４に軸線方向移動可能に嵌合保持されている。回転密封環５は、シール条件及び静止密封環３の構成材に応じて選定された適宜の材料（カーボン，炭化珪素等のセラミックス，ポリテトラフルオロエチレン（ＰＴＦＥ）を主成分とする複合材，超硬合金等）で構成されており、本体部５ｂの先端面は、軸線に直交する円環状の平滑平面である密封端面（回転側密封端面）５ａに構成されている。回転密封環５は、図２に示す如く、その基端部（二次シール部５ｃの基端部）にこれと同一内外径の金属製（ステンレス鋼等）のドライブカラー１４をドライブピン１５（及びスプリング部材７）により相対回転不能に衝合連結すると共に、このドライブカラー１４に固着したドライブピン１６をスプリングリテーナ１２の基端円筒部１２ｃに形成した貫通孔１２ｄに挿通させることにより、軸線方向移動を所定範囲で許容した状態で回転軸４に対して相対回転不能に保持されている。なお、Ｏリング６の軸線方向移動は、スプリングリテーナ１２の中間円筒部１２ｂと回転密封環５の本体部５ｂとの対向端面によって係止規制されている。 As shown in FIGS. 1 and 2, the rotary seal ring 5 is loosely fitted to a main body portion 5 b that is slidably fitted in the tip cylindrical portion 12 a of the spring retainer 12 in an axial direction and an intermediate cylindrical portion 12 b of the spring retainer 12. The secondary seal portion 5c is a cylindrical body, and the rotary shaft 4 is in the secondary seal state with the O-ring 6 interposed between the secondary seal portion 5c and the tip cylindrical portion 12a of the spring retainer 12. It is fitted and held so that it can move in the direction. The rotary seal ring 5 is made of an appropriate material selected according to the sealing conditions and the constituent material of the stationary seal ring 3 (a composite material mainly composed of carbon, ceramics such as silicon carbide, polytetrafluoroethylene (PTFE), super The distal end surface of the main body portion 5b is configured as a sealed end surface (rotary side sealed end surface) 5a which is an annular smooth plane orthogonal to the axis. As shown in FIG. 2, the rotary seal ring 5 has a drive collar 14 made of a metal (stainless steel or the like) having the same inner and outer diameters as a drive pin 15 (base end portion of the secondary seal portion 5c). And the spring member 7) are connected to each other so as not to rotate relative to each other, and the drive pin 16 fixed to the drive collar 14 is inserted into the through hole 12d formed in the proximal cylindrical portion 12c of the spring retainer 12, thereby In a state where the movement is allowed within a predetermined range, the rotation shaft 4 is held so as not to rotate relative to the rotation shaft 4. The movement of the O-ring 6 in the axial direction is restricted by the opposed end surfaces of the intermediate cylindrical portion 12 b of the spring retainer 12 and the main body portion 5 b of the rotary seal ring 5.
スプリング７は、図１に示す如く、スプリングリテーナ１２の基端円筒部１２ｃとドライブカラー１４との間に周方向に等間隔を隔てて装填した複数本の圧縮コイルスプリング７ａで構成されており、回転密封環５を静止密封環３へと押圧附勢している。 As shown in FIG. 1, the spring 7 is composed of a plurality of compression coil springs 7 a loaded at equal intervals in the circumferential direction between the base cylindrical portion 12 c of the spring retainer 12 and the drive collar 14. The rotary seal ring 5 is urged against the stationary seal ring 3.
而して、上記構成のドライコンタクトメカニカルシールにあっては、本発明に従って、密封端面３ａ，５ａ間での摩擦熱，摩耗の発生及び密封端面３ａ，５ａ間からの漏れを確実に防止すべく、次のような工夫が施されている。 Thus, according to the present invention, in the dry contact mechanical seal having the above-described configuration, frictional heat and wear between the sealed end surfaces 3a and 5a and leakage from the sealed end surfaces 3a and 5a should be reliably prevented. The following measures have been taken.
すなわち、静止側密封端面３ａに、回転側密封端面５ａにより閉塞された環状のバリア空間１７を凹設すると共に、シールケース２及び静止密封環３に、これらを貫通してバリア空間１７に連通する一連のバリア流体供給路１８を形成し、バリア流体供給路１８からバリア空間１７にバリア流体１９を供給してバリア空間１７内の圧力ｐを高圧ガス領域（機内ガス領域）Ａの圧力Ｐより０．０５〜０．３ＭＰａ高圧となるように保持することにより、バリア空間１７内のバリア流体圧力ｐにより回転密封環５を静止密封環３から離間する方向へと押圧する開力Ｆｏがスプリング７の附勢力及び前記ガス領域の流体圧力Ｐにより回転密封環５を静止密封環３へと押圧する閉力Ｆｓ，Ｆｃとバランスされて、両密封端面３ａ，５ａが接触面圧を生じない状態で相対回転摺接されるように構成してある。 That is, an annular barrier space 17 closed by the rotation-side sealing end surface 5a is recessed in the stationary-side sealing end surface 3a, and the seal case 2 and the stationary sealing ring 3 are passed through and communicated with the barrier space 17. A series of barrier fluid supply paths 18 are formed, the barrier fluid 19 is supplied from the barrier fluid supply path 18 to the barrier space 17, and the pressure p in the barrier space 17 is reduced from the pressure P in the high-pressure gas region (in-machine gas region) A to 0. By holding the pressure of 0.05 to 0.3 MPa, the opening force Fo that presses the rotary seal ring 5 in the direction away from the stationary seal ring 3 by the barrier fluid pressure p in the barrier space 17 is applied to the spring 7. Balanced with the closing forces Fs and Fc that press the rotary seal ring 5 against the stationary seal ring 3 by the urging force and the fluid pressure P in the gas region, both sealed end surfaces 3a and 5a generate a contact surface pressure. It is configured to be relatively rotated in sliding contact with the absence.
バリア空間１７は、図３に示す如く、静止側密封端面３ａに形成された凹溝により形成されている。なお、バリア空間１７ないし凹溝の内外径ｄ１，ｄ２は静止側密封端面３ａの内外径Ｄ１，Ｄ２とｄ１＞Ｄ１，ｄ２＜Ｄ２の関係を有するものであることはいうまでもない。 As shown in FIG. 3, the barrier space 17 is formed by a concave groove formed in the stationary-side sealed end surface 3 a. Needless to say, the inner and outer diameters d1 and d2 of the barrier space 17 or the concave groove have a relationship of inner and outer diameters D1 and D2 of the stationary-side sealed end surface 3a and d1> D1, d2 <D2.
バリア流体供給路１８は、図１に示す如く、シールケースに形成されたケース側通路１８ａと静止密封環３に形成された密封環側通路１８ｂとケース側通路１８ａの適所に配設された絞り器１８ｃとからなり、シールケース２外に設けたバリア流体供給・制御装置２０によりバリア流体１９が供給され、バリア空間１７内が上記した圧力ｐ（高圧ガス領域Ａより０．０５〜０．３ＭＰａ高圧となる圧力）に保持される。ケース側通路１８ａは、図１に示す如く、シールケース２を径方向に貫通するもので、その一端部はシールケース２の外周部に開口して後述するバリア流体供給装置２０に接続されており、その他端部はシールケース２の内周部に開口された環状の凹溝１８ｄに形成されている。密封環側通路１８ｂは、図１に示す如く、静止密封環３の外周面から静止側密封端面３ａへと貫通されたもので、複数本（1本のみ図示）形成されている。各密封環側通路１８ａの一端部は凹溝１８ｄに開口されており、その他端部はバリア空間１７に開口されている。なお、凹溝１８ｄ及びこれと密封環側通路通路１８ｂとの接続部分はＯリング８，９によりシールされている。 As shown in FIG. 1, the barrier fluid supply passage 18 includes a case-side passage 18a formed in the seal case, a sealing-ring-side passage 18b formed in the stationary sealing ring 3, and a throttle disposed at appropriate positions of the case-side passage 18a. The barrier fluid 19 is supplied by a barrier fluid supply / control device 20 provided outside the seal case 2 and the pressure in the barrier space 17 is 0.05 to 0.3 MPa from the high pressure gas region A described above. Maintained at a high pressure). As shown in FIG. 1, the case side passage 18 a penetrates the seal case 2 in the radial direction, and one end thereof opens to the outer peripheral portion of the seal case 2 and is connected to a barrier fluid supply device 20 described later. The other end portion is formed in an annular concave groove 18 d opened in the inner peripheral portion of the seal case 2. As shown in FIG. 1, the sealing ring side passage 18 b penetrates from the outer peripheral surface of the stationary sealing ring 3 to the stationary side sealing end surface 3 a, and a plurality of (only one is shown) are formed. One end portion of each seal ring side passage 18 a is opened in the groove 18 d, and the other end portion is opened in the barrier space 17. The concave groove 18d and the connecting portion between the groove 18d and the sealing ring side passage 18b are sealed by O-rings 8 and 9.
絞り器１８ｃは、この例では、図１及び図３に示す如く、ケース側通路１８ａの適所であって凹溝１８ｄより上流側の部位に配設されており、オリフィス、毛細管又は多孔質部材等で構成されている。 In this example, as shown in FIGS. 1 and 3, the restrictor 18c is disposed at an appropriate position of the case-side passage 18a and upstream of the concave groove 18d. The restrictor 18c is an orifice, a capillary, a porous member, or the like. It consists of
バリア流体供給・制御装置２０は、バリア流体１９をバリア流体供給経路１８からバアリ空間１７に供給すると共に、バリア空間１７内を高圧ガス領域（機内ガス領域）Ａの圧力Ｐより０．０５〜０．３ＭＰａ高い圧力ｐに保持すべく圧力制御するものである（Ｐ＋０．０５ＭＰａ≦ｐ≦Ｐ＋０．３ＭＰａ）。 The barrier fluid supply / control device 20 supplies the barrier fluid 19 from the barrier fluid supply path 18 to the barrier space 17 and 0.05 to 0 from the pressure P of the high-pressure gas region (in-machine gas region) A in the barrier space 17. The pressure is controlled so as to keep the pressure p high by 3 MPa (P + 0.05 MPa ≦ p ≦ P + 0.3 MPa).
ところで、回転密封環５に作用する閉力は、スプリング７の附勢力により回転密封環５を静止密封環３へと押圧する押圧力Ｆｓと機内ガス領域Ａの流体（ガス）による背圧Ｐにより回転密封環５を静止密封環３へと押圧する押圧力Ｆｃであり、背圧Ｐによる閉力Ｆｃは、図３に示す如く、回転密封環５に作用する背圧つまり機内ガス領域の圧力Ｐと静止側密封端面３ａの内径Ｄ１とＯリング６による回転密封環５の二次シール面の径つまり回転密封環５の二次シール部５ｃの内径Ｄ３とによって決定され、Ｆｃ＝Ｐ(π／４)（(Ｄ３)2-(Ｄ１)2）で与えられる。一方、回転密封環５に作用する開力は、バリア空間１７内のバリア流体圧力ｐにより回転密封環５を静止密封環３から離間させる方向へと押圧する押圧力Ｆｏであり、この開力Ｆｏは、図３に示す如く、バリア流体１９の圧力ｐとバリア空間１７の内外径ｄ１，ｄ２によって決定され、Ｆｏ＝ｐ(π／４)（(ｄ２)2-(ｄ１)2）で与えられる。 By the way, the closing force acting on the rotary seal ring 5 is based on the pressing force Fs that presses the rotary seal ring 5 against the stationary seal ring 3 by the biasing force of the spring 7 and the back pressure P due to the fluid (gas) in the in-machine gas region A. This is a pressing force Fc that presses the rotary seal ring 5 to the stationary seal ring 3, and the closing force Fc due to the back pressure P is a back pressure acting on the rotary seal ring 5, that is, a pressure P in the in-machine gas region, as shown in FIG. And the inner diameter D1 of the stationary side sealing end surface 3a and the diameter of the secondary seal surface of the rotary seal ring 5 by the O-ring 6, that is, the inner diameter D3 of the secondary seal portion 5c of the rotary seal ring 5, Fc = P (π / 4) ((D3) 2- (D1) 2 ). On the other hand, the opening force acting on the rotary seal ring 5 is a pressing force Fo that presses the rotary seal ring 5 away from the stationary seal ring 3 by the barrier fluid pressure p in the barrier space 17. 3 is determined by the pressure p of the barrier fluid 19 and the inner and outer diameters d1 and d2 of the barrier space 17, and is given by Fo = p (π / 4) ((d2) 2 − (d1) 2 ). .
而して、バリア空間１７内の圧力ｐ並びにバリア空間１７の内外径ｄ１，ｄ２、静止側密封端面３ａの内径Ｄ１、二次シール部５ｃの内径Ｄ３及びスプリング７の附勢力は、下記（１）（２）の条件が満足されるように制御，設定される。 And Thus, inner and outer diameters d1, d2 of the pressure p and the barrier space 17 within the barrier space 17, the biasing force of the internal diameter D3 and the spring 7 of an inner diameter D1, the secondary sealing portion 5c of the stationary side sealing end face 3a are following (1 ) It is controlled and set so that the condition of (2) is satisfied.
(１)バリア空間１７内の圧力（バリア流体圧）ｐが高圧ガス領域（機内ガス領域）Ａの圧力Ｐより０．０５〜０．３ＭＰａ高いこと。すなわち、Ｐ＋０．０５ＭＰａ≦ｐ≦Ｐ＋０．３ＭＰａであること。 (1) The pressure (barrier fluid pressure) p in the barrier space 17 is 0.05 to 0.3 MPa higher than the pressure P in the high-pressure gas region (in-machine gas region) A. That is, P + 0.05 MPa ≦ p ≦ P + 0.3 MPa.
(２)開力Ｆｏと閉力Ｆｓ，Ｆｃとがバランスされること。すなわち、Ｆｏ＝Ｆｓ＋Ｆｃであり、具体的にはｐ(π／４)（(ｄ２)2-(ｄ１)2）＝Ｆｓ＋Ｐ(π／４)（(Ｄ３)2-(Ｄ１)2）であること。 (2) The opening force Fo and the closing forces Fs and Fc are balanced. That is, Fo = Fs + Fc, specifically, p (π / 4) ((d2) 2- (d1) 2 ) = Fs + P (π / 4) ((D3) 2- (D1) 2 ). .
すなわち、機内ガス領域Ａの圧力Ｐに応じて上記(１)の範囲でバリア流体１９の圧力ｐを想定し、この想定されたバリア流体圧力ｐ及び機内ガス領域圧力Ｐに基づいて(２)の条件、つまりｐ(π／４)（(ｄ２)2-(ｄ１)2）＝Ｆｓ＋Ｐ(π／４)（(Ｄ３)2-(Ｄ１)2）の条件が満足されるように、バリア空間１７の内外径ｄ１，ｄ２、静止側密封端面３ａの内径Ｄ１、二次シール部５ｃの内径Ｄ３及びスプリング７の附勢力（各圧縮コイルスプリング７ａのバネ力）を設定する。そして、バリア流体供給・制御装置２０により、上記(２)の条件が満足されるように、上記(１)の範囲内でバリア空間１７内の圧力ｐを制御するのである。なお、このようなバリア流体・制御供給装置２０による圧力制御システムは格別のものではなく、周知，公知の圧力制御システムを使用することができる。 That is, the pressure p of the barrier fluid 19 is assumed in the range of the above (1) according to the pressure P in the in-machine gas region A, and based on the assumed barrier fluid pressure p and the in-machine gas region pressure P of (2) The barrier space 17 is such that the condition, that is, p (π / 4) ((d2) 2- (d1) 2 ) = Fs + P (π / 4) ((D3) 2- (D1) 2 ) is satisfied. The inner and outer diameters d1 and d2, the inner diameter D1 of the stationary sealing end surface 3a, the inner diameter D3 of the secondary seal portion 5c, and the biasing force of the spring 7 (spring force of each compression coil spring 7a) are set. The barrier fluid supply / control device 20 controls the pressure p in the barrier space 17 within the range of (1) so that the condition (2) is satisfied. In addition, the pressure control system by such a barrier fluid / control supply apparatus 20 is not special, and a well-known and well-known pressure control system can be used.
以上のように構成されたドライコンタクトメカニカルシールにあっては、バリア流体１９をバリア空間１７に供給して、バリア空間１７内を上記(１)(２)の条件を満足する圧力ｐに制御，保持させることにより、密封端面３ａ，５ａが接触面圧を生じない状態で相対回転摺接されることになる。 In the dry contact mechanical seal constructed as described above, the barrier fluid 19 is supplied to the barrier space 17, and the pressure in the barrier space 17 is controlled to satisfy the conditions (1) and (2). By holding, the sealing end faces 3a and 5a are brought into relative rotational sliding contact with no contact surface pressure.
したがって、密封端面３ａ，５ａ間に接触面圧が生じないことから、密封環３，５が如何なる構成材料で構成されていても、密封端面３ａ，５ａには摩擦熱や摩耗が殆ど生じない。その結果、密封端面３ａ，５ａにシール機能に悪影響を及ぼすような熱歪や異常摩耗が生じることがなく、良好なシール機能が発揮される。 Therefore, no contact surface pressure is generated between the sealed end faces 3a and 5a, so that no matter what the constituent material of the seal rings 3 and 5 is, frictional heat and wear hardly occur on the sealed end faces 3a and 5a. As a result, the sealing end surfaces 3a and 5a are free from thermal distortion and abnormal wear that adversely affect the sealing function, and a good sealing function is exhibited.
また、密封端面３ａ，５ａは接触面圧が生じないものの相対回転摺接すること及びバリア空間１７内のバリア流体圧ｐが上記(１)の条件を満足することから、高圧ガス領域である機内ガス領域Ａから大気領域である機外ガス領域Ｂに機内ガスが漏洩することが全くなく、完璧なシール機能を発揮することができる。 In addition, since the sealing end surfaces 3a and 5a do not generate contact surface pressure but are in relative rotational sliding contact and the barrier fluid pressure p in the barrier space 17 satisfies the above condition (1), the in-machine gas which is a high-pressure gas region. No in-machine gas leaks from the area A to the out-of-machine gas area B, which is the atmospheric area, and a perfect sealing function can be exhibited.
すなわち、バリア空間１７内の流体圧ｐが機内ガス領域Ａの圧力Ｐより高圧であることから、機内ガスが密封端面３ａ，５ａから漏洩することがなく、機内ガスの漏洩が完璧に阻止される。 That is, since the fluid pressure p in the barrier space 17 is higher than the pressure P in the in-machine gas region A, the in-machine gas does not leak from the sealed end faces 3a and 5a, and the leak of the in-machine gas is completely prevented. .
ところで、バリア空間１７内の圧力ｐと機内ガス領域Ａの圧力Ｐとの差圧ΔＰ（＝ｐ−Ｐ）が０．０５ＭＰａ未満であると、機内ガスの漏洩を確実に阻止することができず、かかる漏洩の確実な阻止を図るためにはΔＰ≧０．０５ＭＰａであることが必要である。一方、当該差圧ΔＰが０．３ＭＰａを超えると、バリア空間１７内のバリア流体１９が密封端面３ａ，５ａ間から機内ガス領域Ａへ漏れ続けることになり、バリア空間１７内を(２)の条件を満足する圧力ｐに保持しておくことが困難となり、密封端面３ａ，５ａが非接触状態となり易い。しかし、ΔＰ≦０．３ＭＰａであれば、バリア空間１７から機内ガス領域Ａへのバリア流体１９の漏れが殆どないか、あってもその漏洩量は極く僅かなものとなる。特に、バリア流体１９が窒素ガス等の気体である場合には、ΔＰ≦０．１ＭＰａとしておくことにより、上記(２)の条件を満足しつつバリア流体１９の密封端面３ａ，５ａ間からの漏洩を必要最小限に抑制することができる。したがって、バリア流体１９の圧力ｐは上記(１)の範囲（０．０５ＭＰａ≦ΔＰ≦０．３ＭＰａ）としておく必要があり、バリア流体１９が気体である場合には０．０５ＭＰａ≦ΔＰ≦０．１ＭＰａとしておくのが良い。また、密封端面３ａ，５ａから機内ガス領域Ａ（及び機外ガス領域Ｂ）へのバリア流体１９の漏れ量は、バリア流体供給路１８に絞り器１８ｃを配設しておくことにより、より抑制されることになる。 By the way, when the pressure difference ΔP (= p−P) between the pressure p in the barrier space 17 and the pressure P in the in-machine gas region A is less than 0.05 MPa, it is not possible to reliably prevent leakage of the in-machine gas. In order to surely prevent such leakage, it is necessary that ΔP ≧ 0.05 MPa. On the other hand, when the differential pressure ΔP exceeds 0.3 MPa, the barrier fluid 19 in the barrier space 17 continues to leak from between the sealed end faces 3a and 5a to the in-machine gas region A, and the inside of the barrier space 17 is (2). It becomes difficult to maintain the pressure p that satisfies the conditions, and the sealed end faces 3a and 5a are likely to be in a non-contact state. However, if ΔP ≦ 0.3 MPa, there is little or no leakage of the barrier fluid 19 from the barrier space 17 to the in-machine gas region A. In particular, when the barrier fluid 19 is a gas such as nitrogen gas, by setting ΔP ≦ 0.1 MPa, leakage from between the sealed end faces 3a and 5a of the barrier fluid 19 while satisfying the condition (2) is satisfied. Can be minimized. Therefore, the pressure p of the barrier fluid 19 needs to be in the range of (1) (0.05 MPa ≦ ΔP ≦ 0.3 MPa), and when the barrier fluid 19 is a gas, 0.05 MPa ≦ ΔP ≦ 0. It is good to set it as 1 MPa. Further, the leakage amount of the barrier fluid 19 from the sealed end faces 3a and 5a to the in-machine gas region A (and the out-of-machine gas region B) is further suppressed by disposing the restrictor 18c in the barrier fluid supply path 18. Will be.
このように、上記したドライコンタクメカニカルシールは、端面接触形メカニカルシールの欠点である密封端面３ａ，５ａの摩擦熱や摩耗の発生を可及的に排除しつつ、端面接触形メカニカルシールの利点である被密封流体（機内ガス領域Ａの流体）の漏れ阻止性を更に完璧なものに改善したものであり、ドライ雰囲気において漏れを許容しない用途にも好適に使用することができるものである。 Thus, the dry contact mechanical seal described above has the advantages of the end face contact type mechanical seal while eliminating the frictional heat and wear of the sealed end faces 3a and 5a, which are disadvantages of the end face contact type mechanical seal, as much as possible. The leak prevention property of a certain sealed fluid (fluid in the in-machine gas region A) is further improved, and can be suitably used for applications that do not allow leakage in a dry atmosphere.
ところで、静止側密封端面３ａの外径Ｄ２は、上記(１)(２)を条件を満足するに十分な大きなバリア空間１７を確保しておくために（バリア空間形成用凹溝の径方向幅ｄ２−ｄ１を十分に大きくしておくために）バリア空間１７を形成しない場合に比して大きくしておく必要がある（静止側密封端面３ａの内径Ｄ１の大きさは回転軸４（軸本体１１）の外径により必然的に決定される）。したがって、両密封端面３ａ，５ａの相対回転摺接作用により所定の端面接触形メカニカルシール機能が発揮されるためには、Ｏリング６の外径によって決定されるバランス径Ｄ３を静止側密封端面３ａの外径Ｄ２に応じて大きく設定しておく必要がある。一方、Ｏリング６が回転密封環５と回転軸４（軸本体１１）との間に装填されている場合、バランス径Ｄ３は回転軸４の外径と当該Ｏリング６の断面径によって必然的に決定されることになる（バランス径Ｄ３は回転軸４の外径とＯリング６の断面径との合計値で与えられる）から、Ｏリング６として市販の規格品（ＪＩＳ規格（例えば、ＪＩＳ Ｂ ２４０１，ＪＩＳ Ｗ １５１６，ＪＩＳ Ｗ １５１７等）に定められたＯリング）を使用したのではバランス径Ｄ３を大きく設定することができず、規格品より断面径の大きな特殊Ｏリングを使用せざるを得ない。 By the way, the outer diameter D2 of the stationary-side sealing end surface 3a is set so as to secure a sufficiently large barrier space 17 satisfying the conditions (1) and (2) (the radial width of the groove for forming the barrier space). In order to make d2-d1 sufficiently large, it is necessary to make it larger than when the barrier space 17 is not formed (the size of the inner diameter D1 of the stationary-side sealed end surface 3a is the rotating shaft 4 (shaft body). 11) is inevitably determined by the outer diameter of 11). Therefore, in order for a predetermined end face contact type mechanical seal function to be exhibited by the relative rotational sliding contact action of both the sealing end faces 3a, 5a, the balance diameter D3 determined by the outer diameter of the O-ring 6 is set to the stationary side sealing end face 3a. It is necessary to set large according to the outer diameter D2 . On the other hand, when the O-ring 6 is loaded between the rotary seal ring 5 and the rotary shaft 4 (shaft body 11), the balance diameter D3 is inevitably dependent on the outer diameter of the rotary shaft 4 and the cross-sectional diameter of the O-ring 6. (The balance diameter D3 is given by the total value of the outer diameter of the rotating shaft 4 and the cross-sectional diameter of the O-ring 6). Therefore, a commercially available standard product (JIS standard (for example, JIS B 2401, JIS W 1516, JIS W 1517, etc.), the balance diameter D3 cannot be set larger, and a special O-ring having a larger cross-sectional diameter than standard products must be used. I do not get.
しかし、上記したドライコンタクトシールにあっては、図３に示す如く、Ｏリング６を回転密封環５（二次シール部５ｃ）とスプリングリテーナ１２の先端円筒部１２ａとの間に装填していることから、Ｏリング６として上記規格品（回転軸４の外径に応じて断面径が規定されているもの）を使用しても、先端円筒部１２ａの径方向厚みつまりその外径Ｄ４を調整することによりバランス径Ｄ３を自由に設定することができる。 However, in the dry contact seal described above, as shown in FIG. 3, the O-ring 6 is loaded between the rotary seal ring 5 (secondary seal portion 5 c) and the tip cylindrical portion 12 a of the spring retainer 12. Therefore, even if the above-mentioned standard product (having a cross-sectional diameter defined according to the outer diameter of the rotating shaft 4) is used as the O-ring 6, the radial thickness of the tip cylindrical portion 12a , that is, the outer diameter D4 is adjusted By doing so, the balance diameter D3 can be set freely.
また、先端円筒部１２ａの外径Ｄ４を適宜に設定しておくことにより、当該ドライコンタクトシールを装備した回転機器の運転状況変化等により、高圧ガス領域Ａと低圧ガス領域Ｂとの圧力関係が逆転した場合にも、上記した場合と同様に良好なシール機能を発揮することができる。 In addition, by appropriately setting the outer diameter D4 of the distal end cylindrical portion 12a, the pressure relationship between the high pressure gas region A and the low pressure gas region B is changed due to a change in the operating condition of the rotating equipment equipped with the dry contact seal. Even in the case of reverse rotation, a good sealing function can be exhibited as in the case described above.
例えば、機内ガス領域Ａが正圧である図３に示す状態から、機内ガス領域Ａが負圧となって機内ガス領域Ａと機外ガス領域Ｂとの圧力関係が高低逆転した場合、つまり大気領域である機外ガス領域Ｂが高圧ガス領域となり、負圧ガス領域である機内ガス領域Ａが低圧ガス領域となった場合、閉力Ｆｃを決定するための要素が異なるものの、機内ガス領域Ａの圧力（負圧）を−Ｐとすると、背圧による閉力Ｆｃは、図４に示す如く、静止側密封端面３ａの外径Ｄ１及びＯリング６による回転軸４の二次シール面の径つまりスプリングリテーナ１２の先端円筒部１２ａの外径Ｄ４によって決定され（Ｆｃ＝Ｐ（π／４）（（Ｄ２）2−（Ｄ４）2）で与えられる）、下記（３）（４）の条件を満足することにより、機内ガス領域Ａが図３に示す如く正圧である場合と同一の作用効果が奏せられる。
For example, from the state shown in FIG. 3 where the in-machine gas region A is positive pressure, the in-machine gas region A becomes negative pressure, and the pressure relationship between the in-machine gas region A and the out-of-machine gas region B is reversed, that is, the atmosphere When the out-of-machine gas region B, which is a region, becomes a high-pressure gas region, and the in-machine gas region A, which is a negative pressure gas region, becomes a low-pressure gas region, although the elements for determining the closing force Fc are different, the in-machine gas region A Assuming that the pressure (negative pressure) is −P, the closing force Fc due to the back pressure is such that the outer diameter D1 of the stationary-side sealing end surface 3a and the diameter of the secondary seal surface of the rotating shaft 4 by the O-ring 6 are shown in FIG. That is, it is determined by the outer diameter D4 of the tip cylindrical portion 12a of the spring retainer 12 ( Fc = P (π / 4) (given by (D2) 2 − (D4) 2 )), and the following conditions (3) and (4) As shown in FIG. Same effects as the case of positive pressure are obtained if.
(３)バリア室１７内のバリア流体圧ｐが高圧ガス領域（機外ガス領域）Ｂの圧力(大気圧)より０．０５〜０．３ＭＰａ高いこと。すなわち、０．０５ＭＰａ≦ｐ≦０．３ＭＰａであること。この条件においても、バリア流体１９として窒素ガス等の気体を使用する場合には０．０５ＭＰａ≦ｐ≦０．１ＭＰａとしておくことが好ましい。 (3) The barrier fluid pressure p in the barrier chamber 17 is 0.05 to 0.3 MPa higher than the pressure (atmospheric pressure) in the high pressure gas region (external gas region) B. That is, 0.05 MPa ≦ p ≦ 0.3 MPa. Even under this condition, when a gas such as nitrogen gas is used as the barrier fluid 19, it is preferable that 0.05 MPa ≦ p ≦ 0.1 MPa.
(４)Ｆｏ＝Ｆｓ＋Ｆｃであること。すなわち、ｐ(π／４)（(ｄ２)2-(ｄ１)2）＝Ｆｓ＋Ｐ（π／４）（（Ｄ２）2−（Ｄ４）2）となること。 (4) Fo = Fs + Fc. That is, p (π / 4) ((d2) 2 − (d1) 2 ) = Fs + P (π / 4) ((D2) 2 − (D4) 2 ).
なお、本発明は上記した実施の形態に限定されるものではなく、本発明の基本原理を逸脱しない範囲において適宜に改良，変更することができる。 It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately improved and changed without departing from the basic principle of the present invention.
例えば、図３及び図４に示すドライコンタクトメカニカルシールでは、密封環３，５の相対回転摺接部分３ａ，５ａの内周側領域を機内ガス領域Ａとし、その外周側領域を機外ガス領域Ｂとしたが、本発明は、当該相対回転摺接部分３ａ，５ａの外周側領域を機内ガス領域とし、その内周側領域を機外ガス領域たる大気領域とするドライコンタクトメカニカルシールにも同様に適用することができる。この場合において、機内ガス領域が正圧（Ｐ）の高圧ガス領域となるときは、前記(１)(４)の条件を満足するようにバリア空間１７内の圧力ｐを制御すればよく、機内ガス領域が負圧(−Ｐ)の低圧ガス領域となるときは、前記(２)(３)の条件を満足するようにバリア空間１７内の圧力ｐを制御すればよい。 For example, in the dry contact mechanical seal shown in FIGS. 3 and 4, the inner peripheral region of the relative rotational sliding contact portions 3 a and 5 a of the sealing rings 3 and 5 is an in-machine gas region A, and the outer peripheral region is the out-of-machine gas region. However, the present invention also applies to a dry contact mechanical seal in which the outer peripheral side region of the relative rotational sliding contact portions 3a and 5a is an in-machine gas region, and the inner peripheral region is an atmospheric region which is an outer gas region. Can be applied to. In this case, when the in-machine gas region becomes a positive pressure (P) high-pressure gas region, the pressure p in the barrier space 17 may be controlled so as to satisfy the conditions (1) and (4). When the gas region is a low pressure gas region having a negative pressure (-P), the pressure p in the barrier space 17 may be controlled so as to satisfy the conditions (2) and (3).
１ 回転機器のハウジング
２ シールケース
３ 静止密封環
３ａ 静止側密封端面（静止密封環の密封端面）
４ 回転軸
５ 回転密封環
５ａ 回転側密封端面（回転密封環の密封端面）
６ Ｏリング
７ スプリング
１２ スプリングリテーナ
１２ａ 先端円筒部
１７ バリア空間
１８ バリア流体供給路
１８ａ ケース側通路
１８ｂ 密封環側通路
１８ｃ 絞り器
１９ バリア流体
Ａ 機内ガス領域（高圧ガス領域又は低圧ガス領域）
Ｂ 機外ガス領域（低圧ガス領域又は高圧ガス領域）
DESCRIPTION OF SYMBOLS 1 Housing of rotary equipment 2 Seal case 3 Static sealing ring 3a Static side sealing end surface (sealing end surface of static sealing ring)
4 Rotating shaft 5 Rotating sealing ring 5a Rotating side sealing end face (sealing end face of rotating sealing ring)
6 O-ring 7 Spring 12 Spring retainer 12a End cylindrical part 17 Barrier space 18 Barrier fluid supply path 18a Case side path 18b Sealing ring side path 18c Restrictor 19 Barrier fluid A In-machine gas area (high pressure gas area or low pressure gas area)
B External gas area (low pressure gas area or high pressure gas area)
Claims (3)
回転軸（４）を先端円筒部（１２ａ）とこれより大径の中間円筒部（１２ｂ）とこれより大径の基端円筒部（１２ｃ）とからなる円筒構造のスプリングリテーナ（１２）を嵌合固定したものとし、
回転密封環（５）は、スプリングリテーナ（１２）の先端円筒部（１２ａ）に軸線方向に摺動自在に嵌合された本体部（５ｂ）とスプリングリテーナ（１２）の中間円筒部（１２ｂ）に遊嵌された二次シール部（５ｃ）とからなる円筒体であって、二次シール部（５ｃ）とスプリングリテーナ（１２）の先端円筒部（１２ａ）との間にＯリング（６）を介在させた二次シール状態で回転軸（４）に軸線方向移動可能に嵌合保持されており、
内径（Ｄ１）が回転密封環（５）の密封端面（５ａ）の内径より大きく且つ外径（Ｄ２）が回転密封環（５）の密封端面（５ａ）の外径より小さい静止密封環（３）の密封端面（３ａ）に、回転密封環（５）の密封端面（５ａ）により閉塞された環状のバリア空間（１７）を凹設すると共に、シールケース（２）及び静止密封環（３）に、これらを貫通してバリア空間（１７）にバリア流体（１９）を供給する一連のバリア流体供給路（１８）を形成してあり、
静止密封環（３）の内外径（Ｄ１，Ｄ２）、回転密封環（５）の二次シール部（５ｃ）の内径（Ｄ３）及びスプリングリテーナ（１２）の先端円筒部（１２ａ）の外径（Ｄ４）並びにバリア空間（１７）内のバリア流体圧力を、前記内周側領域（Ａ）が高圧ガス領域であり且つ前記外周側領域（Ｂ）が低圧ガス領域である場合及び当該外周側領域（Ｂ）が高圧ガス領域であり且つ当該内周側領域（Ａ）が低圧ガス領域である場合の何れにおいても当該バリア流体圧力を高圧ガス領域の圧力より０．０５〜０．３ＭＰａ高圧となるように保持すると共にバリア空間（１７）内のバリア流体圧力により回転密封環（５）を静止密封環（３）から離間する方向へと押圧する開力（Ｆｏ）がスプリング（７）の附勢力及び前記ガス領域の流体圧力により回転密封環（５）を静止密封環（３）へと押圧する閉力（Ｆｓ，Ｆｃ）とバランスされて両密封端面（３ａ，５ａ）が接触面圧を生じない状態で相対回転摺接されるように、設定しておくことを特徴とするドライコンタクトメカニカルシール。 A stationary seal ring (3) fixed to the seal case (2) and a rotary seal held by the rotary shaft (4) so as to be movable in the axial direction and pressed and biased to the stationary seal ring (3) by a spring (7). The inner peripheral side area (A) and the outer peripheral side area of the relative rotational sliding contact portion (3a, 5a), which is a gas region, by the relative rotational sliding contact action of the sealing end faces (3a, 5a ) which are opposed to the ring (5) . In the dry contact mechanical seal configured to shield and seal (B) ,
The rotary shaft (4) is fitted with a cylindrical spring retainer (12) consisting of a distal cylindrical portion (12a), an intermediate cylindrical portion (12b) having a larger diameter than this, and a proximal cylindrical portion (12c) having a larger diameter than that. It shall be fixed,
The rotary seal ring (5) includes a main body portion (5b) that is slidably fitted in an axial direction on the tip cylindrical portion (12a) of the spring retainer (12), and an intermediate cylindrical portion (12b) of the spring retainer (12). And a secondary seal portion (5c) loosely fitted to the O-ring (6) between the secondary seal portion (5c) and the tip cylindrical portion (12a) of the spring retainer (12). Is fitted and held on the rotary shaft (4) so that it can move in the axial direction in a secondary seal state with
A stationary sealing ring (3 ) whose inner diameter (D1) is larger than the inner diameter of the sealing end face (5a) of the rotating sealing ring (5) and whose outer diameter (D2) is smaller than the outer diameter of the sealing end face (5a) of the rotating sealing ring (5). sealing end face of) (in 3a), with recessing the occluded annular barrier space (17) by the seal end faces of the rotary seal ring (5) (5a), the seal case (2) and stationary seal ring (3) And a series of barrier fluid supply passages (18) for supplying the barrier fluid (19) to the barrier space (17) through them.
Inner and outer diameters (D1, D2) of the stationary seal ring (3), inner diameter (D3) of the secondary seal portion (5c) of the rotary seal ring (5), and outer diameter of the tip cylindrical portion (12a) of the spring retainer (12) (D4) and the barrier fluid pressure in the barrier space (17) when the inner peripheral region (A) is a high pressure gas region and the outer peripheral region (B) is a low pressure gas region, and the outer peripheral region. In any case where (B) is the high pressure gas region and the inner peripheral region (A) is the low pressure gas region, the barrier fluid pressure is 0.05 to 0.3 MPa higher than the pressure in the high pressure gas region. The opening force (Fo) that holds the rotating seal ring (5) in the direction away from the stationary seal ring (3) by the barrier fluid pressure in the barrier space (17) is biased by the spring (7) . And the fluid pressure in the gas region Pressing the rotary seal ring (5) to the stationary seal ring (3) closing force (Fs, Fc) and balanced with both sealing end faces (3a, 5a) are relatively rotated in sliding contact in a state that does not result in contact surface pressure The dry contact mechanical seal is characterized in that it is set in advance.
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| JP7054638B2 (en) | 2018-03-16 | 2022-04-14 | 東京エレクトロン株式会社 | Seal structure and sealing method |
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|---|---|---|---|---|
| JPS6110052Y2 (en) * | 1979-11-20 | 1986-04-01 | ||
| JP3354524B2 (en) * | 1999-08-16 | 2002-12-09 | 日本ピラー工業株式会社 | Non-contact mechanical seal |
| JP4315394B2 (en) * | 2006-06-27 | 2009-08-19 | 日本ピラー工業株式会社 | mechanical seal |
-
2010
- 2010-03-16 JP JP2010059109A patent/JP5519346B2/en active Active
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| Publication number | Publication date |
|---|---|
| JP2011190902A (en) | 2011-09-29 |
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