JP4724731B2

JP4724731B2 - Mechanical seal and mechanical seal device

Info

Publication number: JP4724731B2
Application number: JP2008103405A
Authority: JP
Inventors: 崇人福本; 正樹宮本
Original assignee: Nippon Pillar Packing Co Ltd
Current assignee: Nippon Pillar Packing Co Ltd
Priority date: 2008-04-11
Filing date: 2008-04-11
Publication date: 2011-07-13
Anticipated expiration: 2028-04-11
Also published as: JP2009250432A

Description

本発明は、ポンプ，ミキサー等の回転機器に軸封手段として使用されるメカニカルシール及びこれを二次シールとして使用するタンデム型シール等のメカニカルシール装置に関するものである。 The present invention relates to a mechanical seal used as a shaft sealing means for a rotary device such as a pump and a mixer, and a mechanical seal device such as a tandem type seal using the same as a secondary seal.

ポンプ，ミキサー等の回転機器に軸封手段として使用されるメカニカルシール装置としては、機内領域側の一次シールたる第１メカニカルシールと大気領域側の二次シールたる第２メカニカルシールとをタンデム配置してなるタンデム型シールが周知である。かかるタンデム型シールにあっては、第１メカニカルシールが、シールケースに固定された静止密封環と、静止密封環の機内領域側に配して、回転軸にＯリングを介して軸線方向に移動可能に保持された回転密封環と、シールケースと回転密封環との間に介装されて回転密封環を静止密封環へと押圧接触させるべく附勢するスプリング部材とを具備して、機内領域たる被密封流体領域と両メカニカルシール間に形成された中間シール領域とを遮蔽シールするように構成されており、第２メカニカルシールが、シールケースにＯリングを介して軸線方向に移動可能に保持された静止密封環と、静止密封環の機内領域側に配して回転軸に固定された回転密封環と、シールケースと静止密封環との間に介装されて静止密封環を回転密封環へと押圧接触させるべく附勢するスプリング部材とを具備して、機外領域たる大気領域と前記中間シール領域とを遮蔽シールするように構成されている（例えば、特許文献１を参照）。 As a mechanical seal device used as a shaft seal means for rotary devices such as pumps and mixers, a first mechanical seal as a primary seal on the in-machine region side and a second mechanical seal as a secondary seal on the air region side are arranged in tandem. A tandem seal is known. In such a tandem type seal, the first mechanical seal is disposed on the in-machine region side of the stationary seal ring fixed to the seal case and the stationary seal ring, and moves in the axial direction via the O-ring on the rotating shaft. An in-flight region comprising: a rotational seal ring that is operatively held; and a spring member that is interposed between the seal case and the rotational seal ring and biases the rotary seal ring into pressure contact with the stationary seal ring. It is configured to shield and seal the sealed fluid region and the intermediate seal region formed between both mechanical seals, and the second mechanical seal is held in the seal case so as to be movable in the axial direction via an O-ring. A stationary sealing ring, a rotational sealing ring disposed on the in-machine region side of the stationary sealing ring and fixed to the rotary shaft, and a stationary sealing ring interposed between the seal case and the stationary sealing ring. Press contact Comprises a spring member for biasing in order to have the said the outboard region serving atmospheric region intermediate the sealing region is configured to shield the seal (e.g., see Patent Document 1).

而して、このように被密封流体領域と大気領域とを中間シール領域を介してシールするタンデム型シールは、単一のメカニカルシールにより被密封流体をシールするシングルシールに比して、被密封流体領域と大気領域とのシールをより確実に行うことができるものであり、しかも第１メカニカルシールによるシール機能が低下，喪失するような非常事態が生じた場合にも、第２メカニカルシールが二次シールないし安全シールとして機能して、被密封流体の大気領域への大量漏れを防止することができるものであり、軸封手段としての信頼性及び安全性に極めて優れるものである。したがって、タンデム型シールにおいて、二次シールたる第２メカニカルシールが適正に機能することが極めて重要である。 Thus, the tandem seal that seals the sealed fluid region and the atmospheric region through the intermediate seal region in this way is more sealed than the single seal that seals the sealed fluid by a single mechanical seal. Sealing between the fluid region and the atmospheric region can be performed more reliably, and even when an emergency situation occurs in which the sealing function of the first mechanical seal is reduced or lost, the second mechanical seal is It functions as a secondary seal or a safety seal, can prevent a large amount of fluid to be sealed from leaking to the atmosphere, and is extremely excellent in reliability and safety as a shaft sealing means. Therefore, in the tandem type seal, it is extremely important that the second mechanical seal as the secondary seal functions properly.

特開２００４−２６６７５６号公報JP 2004-266756 A

しかし、静止密封環は、これとシールケースとの対向周面間にＯリングを適度に圧縮された状態で装填させておくことにより、シールケースとの間のシール機能（二次シール機能）を適正に確保しつつ軸線方向に円滑に移動できる追従性を担保されるものであるが、第２メカニカルシールにあっては、高温条件下では静止密封環の追従性が適正に担保されず、静止密封環の追従不良により適正なメカニカルシール機能が発揮されない虞れがあった。 However, the stationary sealing ring has a sealing function (secondary sealing function) between the stationary sealing ring and the sealing case by loading the O-ring in an appropriately compressed state between the opposed peripheral surfaces of the stationary sealing ring. The second mechanical seal is guaranteed to follow properly and can move smoothly in the axial direction while being properly secured. There is a possibility that an appropriate mechanical seal function may not be exhibited due to poor follow-up of the sealing ring.

すなわち、一般に、シールケースが伝熱効率の高い金属材で構成されると共にＯリングが熱膨張係数の高いゴム材で構成されているために、高温条件下においては、シールケースからＯリングへの伝熱により、Ｏリングが大きく熱膨張して、静止密封環とシールケースとの対向周面間におけるＯリングの圧縮度（締め代）が必要以上に高くなる。その結果、静止密封環とＯリングとの摩擦抵抗が高くなって、静止密封環の軸線方向移動が円滑に行われなくなり、その追従性が不良となる。なお、かかる静止密封環の追従不良の問題は、第２メカニカルシールがシングルシールとして使用される場合においても、同様に生じる。 That is, in general, since the seal case is made of a metal material having a high heat transfer efficiency and the O-ring is made of a rubber material having a high thermal expansion coefficient, the transfer from the seal case to the O-ring is performed under high temperature conditions. Due to the heat, the O-ring expands greatly, and the degree of compression (tightening margin) of the O-ring between the opposed peripheral surfaces of the stationary sealing ring and the sealing case becomes higher than necessary. As a result, the frictional resistance between the stationary seal ring and the O-ring is increased, and the axial movement of the stationary seal ring is not performed smoothly, and the followability is poor. In addition, the problem of the follow-up failure of the stationary seal ring similarly occurs even when the second mechanical seal is used as a single seal.

本発明は、このような問題を生じることなく、高温条件下においても静止密封環の追従性を適正に担保することができる信頼性の高いメカニカルシールを提供すると共に、かかるメカニカルシールを第２メカニカルシールとして使用することにより良好且つ安全なシールを行いうる信頼性の高いメカニカルシール装置を提供することを目的とするものである。 The present invention provides a highly reliable mechanical seal that can appropriately ensure the followability of the stationary seal ring even under high temperature conditions without causing such problems, and this mechanical seal is a second mechanical seal. An object of the present invention is to provide a highly reliable mechanical seal device that can perform a good and safe seal by using it as a seal.

本発明は、第１に、回転軸（２）に回転密封環（１５）を固定すると共に、回転軸（２）が洞貫する金属製のシールケース（１）に、回転密封環（１５）の大気領域側に配して、回転密封環（１５）へと押圧附勢された静止密封環（１４）をゴム製のＯリング（１７）を介して軸線方向移動可能に保持したコンタクトシールであるメカニカルシールにおいて、シールケース（１）が、ケース本体（５）とその大気領域側の端部から内方に突出する環状壁部（７ａ）とその内周端部から機内領域側へと突出する円筒状部（７ｂ）とを具備する円筒状構造物であり、静止密封環（１４）が、シールケース（１）と非接触の状態で円筒状部（７ｂ）にＯリング（１７）を介して外嵌保持されたものであって、回転密封環（１５）に押圧接触する密封端面（１４ａ）にこれと同心をなす連続的な環状形状又は断続的な環状形状の凹溝（２１）を形成すると共に当該凹溝（２１）から当該静止密封環（１４）と環状壁（７ａ）との間へと貫通する連通路（２２）を形成したものであり、環状壁部（７ａ）、円筒状部（７ｂ）及び両密封環（１４，１５）と回転軸（２）との対向周面間には大気領域（Ｂ）へと連通する環状隙間が形成されており、シールケース（１）の環状壁部（７ａ）における大気領域（Ｂ）に臨む面に放熱フィン（３１）を突設すると共に、回転軸（２）に、大気領域（Ｂ）における放熱フィン（３１）の対向位置に配して、回転軸（２）の回転に伴って当該放熱フィン（３１）へと送風すべく回転せしめられる送風ファン（３２）を設けてあることを特徴とするメカニカルシールを提案するものである。 The present invention, in the first, to fix the rotary seal ring (15) to the rotating shaft (2), a metal seal case the rotary shaft (2) is Horanuki (1), the rotary seal ring (15) of disposing the atmosphere region side, the rotary seal ring (15) to the pressing biased been stationary seal ring (14) contacts the seal which holds axially movably through a rubber O-ring (17) In the mechanical seal, the seal case (1) includes a case body (5), an annular wall portion (7a) projecting inwardly from an end on the atmosphere region side, and an inner peripheral end portion toward the inboard region side. A cylindrical structure having a protruding cylindrical portion (7b), and the stationary seal ring (14) is in contact with the cylindrical portion (7b) in an O-ring (17) without contact with the seal case (1). Which is externally held through the seal and presses and contacts the rotary seal ring (15). A continuous annular or intermittent annular groove (21) concentric with the surface (14a) is formed on the surface (14a), and the stationary sealing ring (14) and the annular wall (7a) are formed from the groove (21). ), And the annular wall portion (7a), the cylindrical portion (7b), both the sealing rings (14, 15) and the rotating shaft (2). An annular gap communicating with the atmospheric region (B) is formed between the opposed peripheral surfaces, and a heat radiating fin (31) is formed on the surface facing the atmospheric region (B) in the annular wall portion (7a) of the seal case (1 ). while projecting a, the rotary shaft (2), by arranging a position facing the heat radiating fins (31) in the air region (B), to in accordance with the rotation of the rotary shaft (2) the heat radiating fins (31) Mechanica, characterized in that is provided with a blower fan is rotated in order to blast (32) It is intended to propose a seal.

また、本発明は、第２に、回転機器のハウジングに取り付けられた金属製のシールケース（１）とこれを洞貫する当該回転機器の回転軸（２）との間に、機内領域側の第１メカニカルシール（３）と機外領域側の第２メカニカルシール（４）とを軸線方向に並列配置してなるメカニカルシール装置であって、第２メカニカルシール（４）が、シールケース（１）にゴム製のＯリング（１７）を介して軸線方向に移動可能に保持された静止密封環（１４）と、静止密封環（１４）の機内領域側に配して回転軸に固定された回転密封環（１５）と、シールケース（１）と静止密封環（１４）との間に介装されて静止密封環（１４）を回転密封環（１５）へと押圧接触させるべく附勢するスプリング部材（１６）とを具備して、機外領域たる大気領域（Ｂ）と両メカニカルシール（３，４）間に形成される中間シール領域（Ｃ）とを遮蔽シールするように構成されたコンタクトシールであるメカニカルシール装置において、シールケース（１）が、ケース本体（５）とその大気領域側の端部から内方に突出する環状壁部（７ａ）とその内周端部から機内領域側へと突出する円筒状部（７ｂ）とを具備する円筒状構造物であり、第２メカニカルシール（４）の静止密封環（１４）が、シールケース（１）と非接触の状態で円筒状部（７ｂ）にＯリング（１７）を介して外嵌保持されたものであって、回転密封環（１５）に押圧接触する密封端面（１４ａ）にこれと同心をなす連続的な環状形状又は断続的な環状形状の凹溝（２１）を形成すると共に当該凹溝（２１）から当該静止密封環（１４）と環状壁（７ａ）との間へと貫通する連通路（２２）を形成したものであり、環状壁部（７ａ）、円筒状部（７ｂ）及び第２メカニカルシール（４）の両密封環（１４，１５）と回転軸（２）との対向周面間には大気領域（Ｂ）へと連通する環状隙間が形成されており、シールケース（１）の環状壁部（７ａ）における大気領域（Ｂ）に臨む面に放熱フィン（３１）を突設すると共に、回転軸（２）に、大気領域（Ｂ）における放熱フィン（３１）の対向位置に配して、回転軸（２）の回転に伴って当該放熱フィン（３１）へと送風すべく回転せしめられる送風ファン（３２）を設けてあることを特徴とするメカニカルシール装置を提案するものである。 In addition, the present invention secondly, between the metal seal case (1) attached to the housing of the rotating device and the rotating shaft (2) of the rotating device penetrating the metal sealing case (1) , A mechanical seal device in which a first mechanical seal (3) and a second mechanical seal (4) on the outside region side are arranged in parallel in the axial direction, wherein the second mechanical seal (4) is a seal case (1 ) And a stationary seal ring (14) held movably in the axial direction via a rubber O-ring (17) , and the stationary seal ring (14) disposed on the in-machine region side and fixed to the rotating shaft. The rotary seal ring (15) is interposed between the seal case (1) and the stationary seal ring (14) to urge the stationary seal ring (14) so as to press and contact the rotary seal ring (15) . It comprises a spring member (16), outside the region serving air territory In the mechanical seal device is a contact seal that is configured to shield seals the intermediate seal region (C) which is formed (B) and between both mechanical seals (3, 4), the seal case (1), Case A cylindrical shape comprising a main body (5), an annular wall portion (7a) projecting inward from the end on the atmosphere region side, and a cylindrical portion (7b) projecting from the inner peripheral end portion toward the in-machine region side. The stationary seal ring (14) of the second mechanical seal (4) is externally fitted to the cylindrical part (7b) via the O-ring (17) in a non-contact state with the seal case (1). And forming a continuous annular or intermittent annular groove (21) concentric with the sealing end face (14a) in pressure contact with the rotary sealing ring (15). The stationary sealing ring (1 ) And the annular wall (7a), a communication passage (22) is formed, and both the annular wall portion (7a), the cylindrical portion (7b), and the second mechanical seal (4) are sealed. An annular gap communicating with the atmosphere region (B) is formed between the opposed peripheral surfaces of the rings (14, 15) and the rotating shaft (2), and the annular wall (7a) of the seal case (1) is formed . while projecting radiation fins (31) on the surface facing the air space (B), the rotary shaft (2), by arranging a position facing the heat radiating fins (31) in the air region (B), the rotation shaft (2 ) Is provided with a blower fan (32) that is rotated to blow air to the heat dissipating fin (31) .

本発明のメカニカルシールにあっては、シールケースを空冷することができるから、高温条件下においても、ゴム製のＯリングがシールケースからの伝熱により熱膨張することがなく、シールケースと静止密封環との間におけるＯリングの締め代を適正に維持することができる。したがって、静止密封環がシールケースとの間を適正に二次シールされた状態で良好な追従機能を発揮して、信頼性の高いメカニカルシール機能を発揮することができる。しかも、シールケースの空冷手段の駆動源として回転軸を利用するため、格別の冷却設備を必要とせず、メカニカルシールのイニシャルコスト及びランニングコストが高くなることもない。 In the mechanical seal of the present invention, since the seal case can be air-cooled, the rubber O-ring does not thermally expand due to heat transfer from the seal case even under high temperature conditions, and the seal case is stationary. The interference of the O-ring with the sealing ring can be properly maintained. Therefore, a good follow-up function can be exhibited in a state where the stationary seal ring is properly secondary-sealed with the seal case, and a highly reliable mechanical seal function can be exhibited. In addition, since the rotating shaft is used as a drive source for the air cooling means of the seal case, no special cooling equipment is required, and the initial cost and running cost of the mechanical seal are not increased.

また、本発明のメカニカルシール装置にあっては、高温条件下においても第２メカニカルシールにおける静止密封環の追従性を適正に担保することができ、第２メカニカルシールを二次シールないし安全シールとして適正に機能させることができる。したがって、本発明によれば、信頼性の高いメカニカルシール装置を提供することができる。 In the mechanical seal device of the present invention, the followability of the stationary seal ring in the second mechanical seal can be properly ensured even under high temperature conditions , and the second mechanical seal can be used as a secondary seal or safety seal. It can function properly. Therefore, according to the present invention, a highly reliable mechanical seal device can be provided.

以下、本発明の実施の形態を図面に基づいて具体的に説明する。図１は本発明に係るメカニカルシールを二次シール（第２メカニカルシール）として使用するメカニカルシール装置の一例を示す半截の縦断側面図であり、図２は図１の要部を拡大して示す詳細図であり、図３は当該メカニカルシール装置の要部（空冷手段）を立体的に示す斜視図である。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a vertical side view of a half-pitch showing an example of a mechanical seal device using a mechanical seal according to the present invention as a secondary seal (second mechanical seal), and FIG. 2 is an enlarged view of the main part of FIG. FIG. 3 is a detailed perspective view, and FIG. 3 is a perspective view three-dimensionally showing the main part (air cooling means) of the mechanical seal device.

図１に示すメカニカルシール装置は、ポンプ，ミキサー等の回転機器に装備されるものであり、回転機器のハウジングに取り付けられたシールケース１とこれを同心状に洞貫する当該回転機器の回転軸２との間に、機内領域側に位置する第１メカニカルシール３と機外領域側に位置する第２メカニカルシール４とを軸線方向に並列状にタンデム配置してなるタンデム型シールである。 The mechanical seal device shown in FIG. 1 is mounted on a rotary device such as a pump and a mixer, and has a seal case 1 attached to a housing of the rotary device and a rotary shaft of the rotary device concentrically penetrating therethrough. 2 is a tandem type seal in which a first mechanical seal 3 located on the in-machine region side and a second mechanical seal 4 located on the outside region side are arranged in tandem in parallel in the axial direction.

シールケース１は、図１に示す如く、ケース本体５の内周部に第１及び第２静止密封環保持部６，７を突出形成した金属製（例えばステンレス鋼）の円筒状構造物である。第２静止密封環保持部７は、ケース本体５の機外領域側（図１における左側）の端部から内方に突出する環状壁部７ａとその内周端部から機内領域側（図１における右側）へと突出する円筒状部７ｂとからなる。回転軸２は、図１に示す如く、軸本体８とこれに嵌挿固定された金属製のスリープ９とからなり、スリーブ９には環状の第１及び第２回転密封環保持部９ａ，９ｂが突出形成されている。 As shown in FIG. 1, the seal case 1 is a metal (for example, stainless steel) cylindrical structure in which first and second stationary seal ring holding portions 6 and 7 protrude from the inner peripheral portion of the case body 5. . The second stationary seal ring holding portion 7 includes an annular wall portion 7a projecting inwardly from an end of the case body 5 on the outboard region side (left side in FIG. 1) and an inboard region side from the inner peripheral end (see FIG. 1). And a cylindrical portion 7b projecting to the right side. As shown in FIG. 1, the rotary shaft 2 includes a shaft main body 8 and a metal sleep 9 fitted and fixed thereto. The sleeve 9 has annular first and second rotary sealing ring holding portions 9a and 9b. Projectingly formed.

第１メカニカルシール３は、図１に示す如く、シールケース１の第１静止密封環保持部６に固定された静止密封環（以下「第１静止密封環」という）１０と、第１静止密封環１０の機内領域側に配して、回転軸２に軸線方向移動可能に保持された回転密封環（以下「第１固定密封環」という）１１と、第１回転密封環１１を第１静止密封環１０へと押圧接触させるべく附勢するスプリング部材１２とを具備して、両密封環１０，１１の対向端面たる密封端面１０ａ，１１ａの相対回転摺接作用により機内領域たる被密封流体領域Ａと両メカニカルシール３，４間に形成される中間シール領域Ｃとを遮蔽するように構成されたコンタクトシールである。 As shown in FIG. 1, the first mechanical seal 3 includes a stationary sealing ring (hereinafter referred to as “first stationary sealing ring”) 10 fixed to a first stationary sealing ring holding portion 6 of the seal case 1, and a first stationary sealing. A rotary seal ring (hereinafter referred to as a “first fixed seal ring”) 11 disposed on the in-machine region side of the ring 10 and held on the rotary shaft 2 so as to be movable in the axial direction, and the first rotary seal ring 11 are first stationary. A sealed fluid region which is an in-machine region due to the relative rotational sliding contact action of the sealed end surfaces 10a and 11a, which are the opposed end surfaces of the seal rings 10 and 11, A contact seal configured to shield A and an intermediate seal region C formed between the mechanical seals 3 and 4.

第１回転密封環１１は、回転軸２のスリーブ９にゴム製のＯリング１３を介して軸線方向移動可能に保持されており、スプリング部材１２は、スリーブ９の第１回転密封環保持部９ａと第１回転密封環１１との間に介装された複数のコイルスプリング（１つのみ図示）で構成されている。両密封環１０，１１の構成材はシール条件等に応じて適宜に選定されるが、一般に、固定部材である第１静止密封環１０はセラミックス，超硬合金等の硬質材で構成されており、可動部材である第１回転密封環１１は第１静止密封環６より軟質で自己潤滑性を有するカーボン等で構成されている。なお、図示していないが、第１回転密封環１１は、これと第１回転密封環保持部９ａとの間に配設したドライブピン手段により、所定範囲での軸線方向移動を許容しつつ回転軸２に対する相対回転を阻止されている。 The first rotary seal ring 11 is held on the sleeve 9 of the rotary shaft 2 so as to be movable in the axial direction via a rubber O-ring 13, and the spring member 12 is a first rotary seal ring holding portion 9 a of the sleeve 9. And a plurality of coil springs (only one shown) interposed between the first rotary seal ring 11 and the first rotary seal ring 11. The constituent materials of both the sealing rings 10 and 11 are appropriately selected according to the sealing conditions and the like. In general, the first stationary sealing ring 10 as a fixing member is made of a hard material such as ceramics or cemented carbide. The first rotary seal ring 11 that is a movable member is made of carbon or the like that is softer and self-lubricating than the first stationary seal ring 6. Although not shown, the first rotary seal ring 11 is rotated while allowing axial movement within a predetermined range by a drive pin means disposed between the first rotary seal ring 11 and the first rotary seal ring holding portion 9a. Relative rotation with respect to the shaft 2 is prevented.

第２メカニカルシール４は、図１及び図２に示す如く、シールケース１の第２静止密封環保持部７に軸線方向に移動可能に保持された静止密封環（以下「第１静止密封環」という）１４と、第２静止密封環１４の機内領域側に配して回転軸２に固定された回転密封環１５と、第２密封環保持部７と第１静止密封環１４との間に介装されて静止密封環１４を回転密封環１５へと押圧接触させるべく附勢するスプリング部材１６とを具備して、両密封環１４，１５の対向端面たる密封端面１４ａ，１５１ａの相対回転摺接作用により前記中間シール領域Ｃと機外領域たる大気領域Ｂとを遮蔽シールするように構成されたコンタクトシールである。 As shown in FIGS. 1 and 2, the second mechanical seal 4 is a stationary sealing ring (hereinafter referred to as “first stationary sealing ring”) held in a second stationary sealing ring holding portion 7 of the sealing case 1 so as to be movable in the axial direction. 14), between the second stationary seal ring 14 and the rotary seal ring 15 disposed on the in-flight region side of the second stationary seal ring 14 and fixed to the rotary shaft 2, and between the second seal ring holder 7 and the first stationary seal ring 14. And a spring member 16 that is interposed to urge the stationary seal ring 14 into a pressing contact with the rotary seal ring 15, so that the sealing end faces 14 a and 151 a that are the opposite end faces of the seal rings 14 and 15 are relatively rotated. The contact seal is configured to shield and seal the intermediate seal region C and the air region B which is an out-of-machine region by contact action.

第２静止密封環１４は、第２静止密封環保持部７の円筒状部７ｂにゴム製のＯリング１７を介して軸線方向移動可能に外嵌保持されている。第２回転密封環１５は、回転軸２の第２回転密封環保持部９ｂに固定されている。スプリング部材１６は、第２静止密封環保持部７の環状壁部７ａと第２静止密封環１４との間に介装された複数のコイルスプリング（１つのみ図示）で構成されている。両密封環１４，１５の構成材はシール条件等に応じて適宜に選定されるが、一般に、固定部材である第２回転密封環１５はセラミックス，超硬合金等の硬質材で構成されており、可動部材である第２静止密封環１４は第２回転密封環１５より軟質で自己潤滑性を有するカーボン等で構成されている。なお、図示していないが、第２静止密封環１４は、これと第２静止密封環保持部７の環状壁部７ａとの間に配設したドライブピン手段により、所定範囲での軸線方向移動を許容しつつシールケース１に対する相対回転を阻止されている。 The second stationary seal ring 14 is externally fitted and held on the cylindrical portion 7b of the second stationary seal ring holding portion 7 via a rubber O-ring 17 so as to be movable in the axial direction. The second rotary seal ring 15 is fixed to the second rotary seal ring holding portion 9 b of the rotary shaft 2. The spring member 16 is composed of a plurality of coil springs (only one is shown) interposed between the annular wall 7 a of the second stationary seal ring holding portion 7 and the second stationary seal ring 14. The constituent materials of both the sealing rings 14 and 15 are appropriately selected according to the sealing conditions and the like, but in general, the second rotary sealing ring 15 as a fixing member is made of a hard material such as ceramics or cemented carbide. The second stationary seal ring 14 that is a movable member is made of carbon or the like that is softer and self-lubricating than the second rotary seal ring 15. Although not shown, the second stationary sealing ring 14 is moved in the axial direction within a predetermined range by drive pin means disposed between the second stationary sealing ring 14 and the annular wall 7a of the second stationary sealing ring holding part 7. Is prevented from rotating relative to the seal case 1.

シールケース１のケース本体５と第２静止密封環１４との対向周面間は、図２に示す如く、軸線方向において第２静止密封環保持部７の環状壁部７ａから密封端面１４ａの近傍まで延びる円筒体１８をケース本体５の内周部に嵌着することによって、狭小の環状隙間である第１絞り路１９とされている。また、ケース本体５と第２回転密封環保持部９ｂとの対向周面間は、図２に示す如く、ケース本体５の内周部に環状凸部５ａを形成することにより、狭小の環状隙間である第２絞り路２０とされている。したがって、中間シール領域Ｃは、これらの絞り路１９，２０によって、第１絞り路１９より機外領域側の中間シール領域部分つまり第２静止密封環１４と第２密封環保持部７の環状壁部７ａとの間のスプリング部材１６が配設されている空間（以下「第１中間シール領域部分」という）Ｃ１と、両絞り路１９，２０間の中間シール領域部分つまり密封端面１４ａ，１５ａの外周側空間（以下「第２中間シール領域部分」という）Ｃ２と、第２絞り路２０より機内領域側の中間シール領域部分つまり第２回転密封環保持部９ｂの機内領域側空間（以下「第３中間シール領域部分」という）Ｃ３とに区画されている。なお、絞り路１９，２０の半径方向幅（内外周面の半径差）は、ガス２５の流れの円滑性や後述する圧力損失の効果等を考慮して適宜に設定されるが、通常、２５〜２５０μｍ程度としておくことが好ましい。 As shown in FIG. 2, the space between the opposing peripheral surfaces of the case body 5 and the second stationary sealing ring 14 of the sealing case 1 is in the vicinity of the sealing end surface 14a from the annular wall portion 7a of the second stationary sealing ring holding portion 7 in the axial direction. By fitting the cylindrical body 18 extending to the inner peripheral part of the case body 5, the first throttle path 19 which is a narrow annular gap is formed. Further, as shown in FIG. 2, a narrow annular gap is formed between the opposing peripheral surfaces of the case main body 5 and the second rotary seal ring holding portion 9b by forming an annular convex portion 5a on the inner peripheral portion of the case main body 5. The second throttle path 20 is. Therefore, the intermediate seal region C is formed by the throttle passages 19 and 20 in the intermediate seal region portion on the outside region side of the first throttle passage 19, that is, the annular wall of the second stationary seal ring 14 and the second seal ring holding portion 7. The space (hereinafter referred to as “first intermediate seal region portion”) C1 between which the spring member 16 is disposed between the portion 7a and the intermediate seal region portion between the throttle paths 19 and 20, that is, the sealing end surfaces 14a and 15a. An outer peripheral side space (hereinafter referred to as “second intermediate seal region portion”) C2 and an intermediate seal region portion closer to the in-machine region side than the second throttle path 20, that is, an in-machine region side space (hereinafter referred to as “second” 3) (referred to as “3 intermediate seal region portion”). The radial widths (radial differences between the inner and outer peripheral surfaces) of the throttle paths 19 and 20 are appropriately set in consideration of the smoothness of the flow of the gas 25, the effect of pressure loss described later, and the like. It is preferable to set it to about ˜250 μm.

第２静止密封環１４の密封端面１４ａには、図１及び図２に示す如く、これと同心をなす連続的な環状形状又は断続的な環状形状の凹溝２１が形成されている。すなわち、この凹溝２１により、密封端面１４ａ，１５ａ間には、図２に示す如く、環状空間２１ａ又は環状をなして同心状に並列する複数の円弧状空間２１ｂが形成される。また、第２静止密封環１４には、図１及び図２に示す如く、当該凹溝２１から第１中間シール領域部分Ｃ１へと貫通する連通路２２が形成されている。なお、連通路２２の本数は、第２静止密封環１４の強度を必要以上に低下させない範囲で適宜に設定することができる。例えば、凹溝２１が連続的な環状形状をなす場合には、一般に、３〜１６本程度の連通路２２を形成しておく。また、凹溝２１が断続的な環状形状をなす場合、つまり複数の円弧状の凹溝２１が環状をなして同心状に並列する場合には、かかる円弧状の凹溝２１の数を３〜１６個として、選択された複数の凹溝２１に夫々連通する連通路２２を形成しておくか、すべての凹溝２１に夫々連通する連通路２２を形成しておく。 As shown in FIGS. 1 and 2, a continuous annular shape or an intermittent annular groove 21 is formed on the sealing end surface 14 a of the second stationary sealing ring 14. That is, the concave groove 21 forms an annular space 21a or a plurality of arcuate spaces 21b that are concentrically arranged in parallel with each other as shown in FIG. 2 between the sealed end faces 14a and 15a. Further, as shown in FIGS. 1 and 2, the second stationary seal ring 14 is formed with a communication path 22 that penetrates from the concave groove 21 to the first intermediate seal region portion C <b> 1. Note that the number of the communication passages 22 can be set as appropriate as long as the strength of the second stationary sealing ring 14 is not lowered more than necessary. For example, when the concave groove 21 has a continuous annular shape, generally, about 3 to 16 communication paths 22 are formed. Further, when the concave grooves 21 have an intermittent annular shape, that is, when a plurality of arc-shaped concave grooves 21 are concentrically arranged in an annular shape, the number of the circular arc-shaped concave grooves 21 is 3 to 3. The communication paths 22 communicating with the plurality of selected concave grooves 21 are formed as 16 or the communication paths 22 communicating with all the concave grooves 21 are formed.

ケース本体５と円筒体１８との対向周面間には環状の給気空間２３ａ，２３ｂが形成されている。この給吸空間は、図２に示す如く、第１給気空間２３ａとこれに連なって機外領域側へと延びる第２給気空間２３ｂとからなる一連の環状空間であって、第２給気空間２３ｂは第１給気空間２３ａより狭小なものとされている。円筒体１８には、図２に示す如く、第２給気空間２３ｂと第１中間シール領域部分Ｃ１とを連通する複数（１つのみ図示）の給気口２４が周方向に所定間隔を隔てて穿設されている。ケース本体５には、図１及び図２に示す如く、中間シール領域Ｃにシールガスないしバージガス２５を給排させる給気通路２６及び排気通路２７が形成されている。給気通路２６は、図１及び図２に示す如く、第１給気空間２３ａに開口されていて、シールガス２５を第１給気空間２３ａ、第２給気空間２３ｂ及び給気口２４を経て、第１中間シール領域部分Ｃ１に供給させる。排気通路２７は、図１及び図２に示す如く、第３中間シール領域部分Ｃ３に開口されており、シールガス２５をシールケース１外に排出する。シールガスないしパージガス２５としては、被密封流体領域Ａ又は大気領域Ｃに漏洩しても支障のないガスが使用されるが、通常、被密封流体と不活性であり且つ無害な窒素ガスが使用される。 Between the opposed peripheral surfaces of the case body 5 and the cylindrical body 18, annular air supply spaces 23 a and 23 b are formed. As shown in FIG. 2, the air supply / intake space is a series of annular spaces including a first air supply space 23a and a second air supply space 23b that extends to the outside region side. The air space 23b is narrower than the first air supply space 23a. As shown in FIG. 2, the cylindrical body 18 has a plurality of (only one shown) air supply ports 24 communicating with the second air supply space 23b and the first intermediate seal region portion C1 at predetermined intervals in the circumferential direction. Have been drilled. As shown in FIGS. 1 and 2, the case body 5 is provided with an air supply passage 26 and an exhaust passage 27 for supplying and discharging seal gas or barge gas 25 to and from the intermediate seal region C. As shown in FIGS. 1 and 2, the air supply passage 26 is opened to the first air supply space 23 a, and seal gas 25 is passed through the first air supply space 23 a, the second air supply space 23 b, and the air supply port 24. After that, the first intermediate seal region portion C1 is supplied. As shown in FIGS. 1 and 2, the exhaust passage 27 is opened to the third intermediate seal region portion C <b> 3 and discharges the seal gas 25 out of the seal case 1. As the seal gas or purge gas 25, a gas that does not interfere with leakage into the sealed fluid region A or the atmospheric region C is used. Usually, nitrogen gas that is inert and harmless with the sealed fluid is used. The

而して、シールケース１と回転軸２との間には、本発明に従って次のような空冷手段が設けられている。 Thus, the following air cooling means is provided between the seal case 1 and the rotating shaft 2 according to the present invention.

すなわち、この空冷手段は、図１〜図３に示す如く、シールケース１における大気領域Ｂに臨む面に放熱フィン３１を突設すると共に、回転軸２に、大気領域Ｂにおける放熱フィン３１の対向位置に配して、回転軸２の回転に伴って当該放熱フィン３１へと送風すべく回転せしめられる送風ファン３２を設けてなる。 That is, as shown in FIGS. 1 to 3, this air-cooling means projects the radiating fins 31 on the surface facing the atmospheric region B in the seal case 1 and faces the radiating fins 31 in the atmospheric region B on the rotary shaft 2. A blower fan 32 that is disposed at a position and is rotated to blow air to the heat radiating fins 31 as the rotary shaft 2 rotates is provided.

放熱フィン３１は、シールケース１における大気領域Ｂに臨む面であってＯリング１７に可及的に近いシールケース部分の面に形成することが好ましく、この例では、図１〜図３に示す如く、第２静止密封環保持部７の環状壁部７ａにおける大気領域側の面に、回転軸２と同心をなす複数の放熱フィン３１を突設してある。 The radiating fins 31 are preferably formed on the surface of the seal case 1 facing the atmospheric region B and on the surface of the seal case portion as close as possible to the O-ring 17. In this example, it is shown in FIGS. As described above, a plurality of heat radiating fins 31 concentric with the rotary shaft 2 are provided on the surface of the annular wall portion 7 a of the second stationary seal ring holding portion 7 on the atmosphere region side.

送風ファン３２は、図１〜図３に示す如く、放熱フィン３１に直対向する位置に配置されており、回転軸２のスリーブ９に嵌合固定された円筒状のハブ３２ａとその外周面に周方向に一定間隔を隔てて突設された複数枚の羽根３２ｂとからなる。ハブ３２ａは、これに螺合させた適当数（１つのみ図示）のスクリュー３３を締め付けることにより、スリーブ９に固定されている。この例では、ハブ３２ａに螺合させた適当数（１つのみ図示）のセットスクリュー３４をスリーブ９を貫通して軸本体８に締め付けることにより、当該ハブ３２ａがスリーブ９と軸本体８との間の連結具（固定具）として兼用されている。羽根３２ｂの形状（回転軸２の軸線に対する傾斜角度等）は、回転軸２の回転方向に応じて、放熱フィン３１への送風機能を発揮しうるように設定されている。羽根３２ｂの枚数は適宜に設定することができるが、一般には、４〜６枚程度としておくことが好ましい。 As shown in FIGS. 1 to 3, the blower fan 32 is disposed at a position directly opposite to the heat dissipating fins 31, and a cylindrical hub 32 a fitted and fixed to the sleeve 9 of the rotating shaft 2 and an outer peripheral surface thereof. It consists of a plurality of blades 32b projecting at a constant interval in the circumferential direction. The hub 32a is fixed to the sleeve 9 by tightening an appropriate number (only one shown) of screws 33 screwed into the hub 32a. In this example, an appropriate number (only one is shown) of set screws 34 screwed into the hub 32 a is passed through the sleeve 9 and fastened to the shaft body 8, so that the hub 32 a is connected between the sleeve 9 and the shaft body 8. It is also used as a connecting tool (fixing tool). The shape of the blades 32b (such as an inclination angle with respect to the axis of the rotary shaft 2) is set so as to exhibit a function of blowing air to the radiating fins 31 in accordance with the rotation direction of the rotary shaft 2. The number of blades 32b can be set as appropriate, but in general, it is preferably about 4-6.

以上のように構成されたタンデム型シールにあっては、回転軸２の回転に伴って送風ファン３２が回転され、放熱フィン３１に向けて送風されることから、放熱フィン３１による放熱と送風ファン３２による送風によってシールケース１が効果的に冷却されることになる。その結果、Ｏリング１７の熱膨張が抑制され、その締め代が適正に維持され、第２静止密封環１４の追従性が高温条件下においても適正に維持，担保される。したがって、第２メカニカルシール４によるシール機能が良好に発揮され、タンデム型シールの信頼性が高くなる。 In the tandem seal configured as described above, the blower fan 32 is rotated with the rotation of the rotary shaft 2 and is blown toward the radiating fins 31. The sealing case 1 is effectively cooled by the air blow by 32. As a result, the thermal expansion of the O-ring 17 is suppressed, the tightening margin is properly maintained, and the followability of the second stationary seal ring 14 is properly maintained and secured even under high temperature conditions. Therefore, the sealing function by the second mechanical seal 4 is satisfactorily exhibited, and the reliability of the tandem seal is increased.

また、シールガスないしバージガス２５は、給気路２６から環状の第１給気空間２３ａに供給され、更に環状の第２給気空間２３ｂを経て複数の吸気口２４から第１中間シール領域部分Ｃ１に導入される。このとき、第２給気空間２３ｂが第１給気空間２３ａより狭小とされていることから、給気路２６から第１給気空間２３ａへのガス導入が一箇所で行われるにも拘わらず、環状の第２給気空間２３ｂ内においては、その全周に亘ってガス２５が均一に導入されることになる。したがって、複数の吸気口２４から第１中間シール領域部分Ｃ１へのガス導入も、当該領域部分Ｃ１にその全域に亘って均一に行われる。なお、第１給気空間２３ａへのガス導入箇所（給気路２６と第１給気空間２３ａとの連通箇所）を基準として、吸気口２４相互の間隔（ピッチ）を周方向において当該箇所から遠ざかるに従って小さくなるように設定しておくことも、第１中間シール領域部分Ｃ１への均一なガス導入に有効となる。而して、第１中間シール領域部分Ｃ１に供給されたガス２５は、第１絞り路１９を通過して第２中間シール領域部分Ｃ２に導入され、更に第２絞り路２０を通過して第３中間シール領域部分Ｃ２に導入され、第３中間シール領域部分Ｃ３から排気路２７へと排出される。このとき、連通路２２から密封端面１４ａ，１５ａ間の空間２１ａ，２１ｂにもガス２５が導入されるが、この空間２１ａ，２１ｂからガス漏れ量、つまり相対回転摺接する密封端面１４ａ，１５ａ間から第２中間シール領域部分Ｃ２へのガス漏れ量は極く僅かであるため、空間２１ａ，２１ｂ及び連通路２２においてはガス流動が生じず、これら２１ａ，２１ｂ，２２の内圧は第１中間シール領域部分Ｃ１のガス圧と略同一に保持される。一方、第１中間シール領域部分Ｃ１から第２中間シール領域部分Ｃ２へのガス導入は狭小の第１絞り路１９を介して行われ、ガス２５が第１絞り路１９を通過する際に圧力損失が生じることから、第２中間シール領域部分Ｃ２のガス圧は第１中間シール領域部分Ｃ１より低くなる。したがって、空間２１ａ，２１ｂ内の圧力つまり密封端面１４ａ，１５ａ間の圧力は、当該密封端面１４ａ，１５ａの外周領域である第２中間シール領域部分Ｃ２の圧力よりも高くなることから、密封端面１４ａ，１５ａは非接触でも接触でもない半接触状態となり、良好なドライコンタクトシール機能が発揮される。特に、凹溝２１を断続的な環状形状をなす場合、つまり密封端面１４ａ，１５ａ間に複数の空間２１ｂが並列形成される場合には、密封端面１４ａ，１５ａの相対回転に伴って当該空間２１ｂに動圧が発生することから、密封端面１４ａ，１５ａの上記半接触状態が有効に維持されることなる。また、第２中間シール領域部分Ｃ２から第３中間シール領域部分Ｃ３へのガス導入も狭小な第２絞り路２０を介して行われることから、第２絞り路２０による圧力損失により、第３中間シール領域部分Ｃ３の圧力は第２中間シール領域部分Ｃ２よりも低くなる。したがって、被密封流体が一次シールたる第１メカニカルシール３の密封端面１０ａ，１１ａから第３中間シール領域部分Ｃ３へと漏洩することがあっても、その漏洩流体は第２中間シール領域部分Ｃ２へと侵入することがなく、そのまま第３中間シール領域部分Ｃ３から排気路２７へ排出される。したがって、被密封流体が低沸点流体，有毒流体，スラリ流体等である場合にも、その漏洩流体が第２メカニカルシール４のシール機能に悪影響を及ぼすことがなく、大気領域Ｂに放出されることもない。 Further, the seal gas or the barge gas 25 is supplied from the air supply passage 26 to the annular first air supply space 23a, and further passes through the annular second air supply space 23b to be supplied from the plurality of intake ports 24 to the first intermediate seal region portion C1. To be introduced. At this time, since the second air supply space 23b is narrower than the first air supply space 23a, the gas introduction from the air supply path 26 to the first air supply space 23a is performed at one place. In the annular second air supply space 23b, the gas 25 is uniformly introduced over the entire circumference. Therefore, gas introduction from the plurality of intake ports 24 to the first intermediate seal region portion C1 is also performed uniformly over the entire region portion C1. Note that the interval (pitch) between the intake ports 24 in the circumferential direction is determined from the location in the circumferential direction with reference to a gas introduction location (a communication location between the supply passage 26 and the first supply space 23a) to the first supply space 23a. It is effective to uniformly introduce gas into the first intermediate seal region portion C1 so as to decrease as the distance increases. Thus, the gas 25 supplied to the first intermediate seal region portion C1 passes through the first constriction passage 19 and is introduced into the second intermediate seal region portion C2, and further passes through the second constriction passage 20 to be the second. It is introduced into the third intermediate seal region portion C2 and discharged from the third intermediate seal region portion C3 to the exhaust passage 27. At this time, the gas 25 is also introduced from the communication passage 22 into the spaces 21a and 21b between the sealed end faces 14a and 15a. The amount of gas leakage from the spaces 21a and 21b, that is, between the sealed end faces 14a and 15a that are in relative rotational sliding contact. Since the amount of gas leakage to the second intermediate seal region portion C2 is very small, no gas flows in the spaces 21a, 21b and the communication passage 22, and the internal pressure of these 21a, 21b, 22 is the first intermediate seal region. It is kept substantially the same as the gas pressure in the portion C1. On the other hand, the gas introduction from the first intermediate seal region portion C1 to the second intermediate seal region portion C2 is performed through the narrow first narrow passage 19, and pressure loss occurs when the gas 25 passes through the first narrow passage 19. Therefore, the gas pressure in the second intermediate seal region portion C2 is lower than that in the first intermediate seal region portion C1. Accordingly, the pressure in the spaces 21a and 21b, that is, the pressure between the sealed end surfaces 14a and 15a is higher than the pressure in the second intermediate seal region portion C2 that is the outer peripheral region of the sealed end surfaces 14a and 15a. 15a is in a semi-contact state that is neither non-contact nor contact, and a good dry contact sealing function is exhibited. In particular, when the concave groove 21 has an intermittent annular shape, that is, when a plurality of spaces 21b are formed in parallel between the sealed end surfaces 14a and 15a, the space 21b is associated with the relative rotation of the sealed end surfaces 14a and 15a. Therefore, the half-contact state of the sealing end surfaces 14a and 15a is effectively maintained. In addition, since the gas introduction from the second intermediate seal region portion C2 to the third intermediate seal region portion C3 is also performed through the narrow second restricting path 20, the third intermediate seal is caused by the pressure loss caused by the second restricting path 20. The pressure in the seal region portion C3 is lower than that in the second intermediate seal region portion C2. Therefore, even if the fluid to be sealed leaks from the sealed end faces 10a and 11a of the first mechanical seal 3 serving as a primary seal to the third intermediate seal region portion C3, the leaked fluid flows to the second intermediate seal region portion C2. Without intruding, and is directly discharged from the third intermediate seal region C3 to the exhaust path 27. Therefore, even when the fluid to be sealed is a low boiling point fluid, a toxic fluid, a slurry fluid, etc., the leaked fluid does not adversely affect the sealing function of the second mechanical seal 4 and is released to the atmosphere region B. Nor.

本発明に係るメカニカルシールを装備したメカニカルシール装置（タンデムシール）の一例を示す半截の縦断側面図である。It is a vertical side view of a half-pitch showing an example of a mechanical seal device (tandem seal) equipped with a mechanical seal according to the present invention. 図１の要部を拡大して示す詳細図である。FIG. 2 is an enlarged detailed view showing a main part of FIG. 1. 当該メカニカルシール装置の要部（空冷手段）を立体的に示す斜視図である。It is a perspective view which shows the principal part (air cooling means) of the said mechanical seal apparatus in three dimensions.

Explanation of symbols

１シールケース
２回転軸
３第１メカニカルシール
４第２メカニカルシール
７ａ環状壁部
７ｂ円筒状部
１４第２静止密封環
１４ａ第２静止密封環の密封端面
１５第２回転密封環
１６スプリング部材
１７Ｏリング
２１凹溝
２２連通路
３１放熱フィン
３２送風ファン
Ａ被密封流体領域（機内領域）
Ｂ大気領域（機外領域）
Ｃ中間シール領域部分
DESCRIPTION OF SYMBOLS 1 Seal case 2 Rotating shaft 3 1st mechanical seal 4 2nd mechanical seal
7a Annular wall
7b Cylindrical part 14 Second stationary seal ring
14a Sealing end face 15 of the second stationary sealing ring 15 Second rotating sealing ring 16 Spring member 17 O-ring
21 groove
22 Communication path 31 Radiation fin 32 Blower fan A Sealed fluid area (in-machine area)
B Atmosphere (outside the aircraft)
C Middle seal area

Claims

Fixes the rotary seal ring (15) to the rotating shaft (2), a metal seal case the rotary shaft (2) is Horanuki (1), by disposing the atmosphere region side of the rotary seal ring (15) In the mechanical seal that is a contact seal that holds the stationary seal ring (14) pressed and urged to the rotary seal ring (15) through the rubber O-ring (17) so as to be movable in the axial direction.
The seal case (1) includes a case main body (5), an annular wall portion (7a) projecting inward from an end portion on the atmosphere region side, and a cylindrical portion projecting from the inner peripheral end portion toward the in-machine region side ( 7b) and a cylindrical structure,
The stationary seal ring (14) is fitted and held on the cylindrical portion (7b) via the O-ring (17) in a non-contact state with the seal case (1), and the rotary seal ring (15). A continuous annular groove or an intermittent annular groove (21) concentric with the sealing end surface (14a) that is pressed against the groove is formed, and the stationary sealing ring (14) is formed from the groove (21). And a communication passage (22) penetrating between and the annular wall (7a),
An annular gap communicating with the atmospheric region (B) is formed between the annular wall (7a), the cylindrical portion (7b), and the opposed peripheral surfaces of both the sealing rings (14, 15) and the rotating shaft (2). And
Annular wall portion of the seal case (1) (7a) as well as projecting radiation fins (31) on the surface facing the air space (B) in the rotating shaft (2), the heat radiation in the air region (B) fins (31 ) And a blower fan (32) that is rotated to blow air to the heat radiating fin (31) as the rotary shaft (2) rotates.

Between the metal seal case (1) attached to the housing of the rotating device and the rotating shaft (2) of the rotating device penetrating therethrough, the first mechanical seal (3) on the in-machine region side and the outside of the device A mechanical seal device in which a region-side second mechanical seal (4) is arranged in parallel in the axial direction, wherein the second mechanical seal (4) is attached to a seal case (1) with a rubber O-ring (17). via the stationary sealing ring is held movably in the axial direction (14), a rotary seal ring fixed to the rotating shaft disposed inboard region side of the stationary seal ring (14) (15), the seal case (1) and comprises a spring member (16) for biasing to the to pressure contact interposed has been stationary seal ring (14) to the rotary seal ring (15) between the stationary seal ring (14) , outside the region serving as the atmosphere area and (B) both mechanical shea In the mechanical seal device is a contact seal that is configured to shield seals the intermediate seal region (C) formed between Le (3,4),
The seal case (1) includes a case main body (5), an annular wall portion (7a) projecting inward from an end portion on the atmosphere region side, and a cylindrical portion projecting from the inner peripheral end portion toward the in-machine region side ( 7b) and a cylindrical structure,
The stationary seal ring (14) of the second mechanical seal (4) is externally held by the cylindrical portion (7b) via the O-ring (17) in a non-contact state with the seal case (1). Thus, a continuous annular shape or an intermittent annular groove (21) concentric with the sealing end face (14a) that press-contacts the rotary seal ring (15) is formed and the groove (21). A communication passage (22) penetrating from the stationary sealing ring (14) to the annular wall (7a).
Between the circumferential surfaces of the annular wall (7a), the cylindrical portion (7b) and the second mechanical seal (4), both of the sealing rings (14, 15) and the rotary shaft (2), go to the atmospheric region (B). An annular gap communicating with the
Annular wall portion of the seal case (1) (7a) as well as projecting radiation fins (31) on the surface facing the air space (B) in the rotating shaft (2), the heat radiation in the air region (B) fins (31 The mechanical seal device is provided with a blower fan (32) which is disposed at a position opposite to the fan shaft and is rotated so as to blow air to the heat radiating fin (31) as the rotary shaft (2) rotates. .