JP4068379B2

JP4068379B2 - Sealing device

Info

Publication number: JP4068379B2
Application number: JP2002104318A
Authority: JP
Inventors: 斉下浦; 朋也稲垣
Original assignee: Mitsubishi Cable Industries Ltd
Current assignee: Mitsubishi Cable Industries Ltd
Priority date: 2002-04-05
Filing date: 2002-04-05
Publication date: 2008-03-26
Anticipated expiration: 2022-04-05
Also published as: JP2003301949A

Description

【０００１】
【発明の属する技術分野】
本発明は、カーエアコン用コンプレッサ等の密封装置に係り、特に密封流体が高圧で、回転軸が高速回転するコンプレッサに対応する密封装置に関する。
【０００２】
【従来の技術】
カーエアコン用コンプレッサ等における流体収納室内の流体、即ち、冷媒及び潤滑剤として作用する油の混合物が、回転軸摺接面から漏れるのを防止する密封装置として、回転軸シールが従来より用いられている。近年、地球温暖化対策において、冷媒としてフロン（ＨＦＣ１３４ａ）の使用を制限することが検討されており、次世代冷媒の候補として二酸化炭素（ＣＯ₂）が注目され、ＣＯ₂を用いたコンプレッサの開発が進められている。しかし、冷媒としてＣＯ₂を用いた場合、コンプレッサの流体圧力がＨＦＣ１３４ａを使用した場合に比べて10倍以上高くなり、この高圧化に対応した密封装置の開発が望まれている。
【０００３】
従来の冷媒を密封する密封装置として、図３に示すようなものが用いられている。この密封装置は、コンプレッサ等のハウジング41と回転軸42との間に介装された回転軸シール43を備えたものであって、流体収納室44の冷媒と油からなる流体を密封する。この回転軸シール43は、アウターケース45にゴム製シール部材46を接着したものを備え、回転軸42に摺接する摺接面に切込溝49を形成した樹脂（特にＰＴＦＥ）からなるシールエレメント47と金具（インナーケース）48とをアウターケース45にかしめられて一体化（把持固定）されている。
【０００４】
さらに、回転軸シール43は、シール部材46の先端部が回転軸42の表面に当接してシールを行うが、回転軸42が回転すると完全にシールしきらず、少量の流体漏れを発生させる。この漏れた流体はシールエレメント47によりシールされることとなり、シール部材46とシールエレメント47とにより回転軸シール43全体として流体の漏れを防止する構造となる。つまり、シール部材46を通過しシールエレメント47の摺接面に設けた螺旋状の切込溝49により、少量漏れた流体は流体収納室44側に押し戻されることによって、回転軸シール43全体としてシール機能を果たしている。
【０００５】
【発明が解決しようとする課題】
しかし、ＣＯ₂を冷媒として使用した場合、流体収納室44が高圧となるためゴム製シール部材46が過大な押圧力を受けシール部材46の摺接部が回転軸42へ強く押圧されるため摩耗・発熱が促進され、ゴム製シール部材46の先端部（摺接部）が硬化し、クラックが発生する原因となっていた。さらに、高圧によりシール部材46がシールエレメント47を必要以上に回転軸42方向に押さえつけ、摩擦による熱が高く、シールエレメント47の摩耗が増大し、シール自体の耐久性の悪化を招く結果となっていた。
【０００６】
また、前述のように、この回転軸シール43は、シール部材46から少量の流体を意図的に漏らす構成であり、漏れた流体の油をシール部材46とシールエレメント47の潤滑材として利用するが、高圧によりシール部材46が予想以上に回転軸42に押し付けられると、流体が全くシールエレメント47に供給されなくなり、シール部材46及びシールエレメント47の摩耗が促進することとなり、回転軸シール43が設計通りに機能しないという問題があった。
【０００７】
上述した冷媒（密封流体）の高圧化に対応するため、その後、図４に示すような密封装置（回転軸シール43Ａ）が提案されている。即ち、ゴム製シール部材46を背面から受持するバックアップ金具51を、付加した構造である。
しかしながら、この図４に示した従来の回転軸シール43Ａでも、最近の高圧化した冷媒（密封流体）に対して、上述と同じ理由で耐久性の面で不十分であることが判明してきた。
【０００８】
そこで本発明は、密封流体の高圧化に対応する密封装置として、高圧の流体による摩耗の促進を抑え、摩擦熱等による発熱を低減して、回転軸シールの耐久性を向上させた密封装置を提供することを目的とする。さらに、ハウジングと回転軸との間への装着作業性を良好に保ち、かつ、小型化を図り、信頼性のある密封装置を提供することを、他の目的とする。
【０００９】
【課題を解決するための手段】
上述の目的を達成するために、本発明は、ハウジングと回転軸との間に介装されるコンプレッサ用密封装置に於て、該回転軸に摺接するゴム製シールリップ部を有する主シール部材と、該主シール部材よりも流体収納室側に配設されて該流体収納室側に延伸する摺接リップ部を有する減圧シール部材とを、共通アウターケースによって把持固定して構成され；かつ、上記減圧シール部材は、横断面形状が軸心直交方向に細長い矩形状の外径側基部と、該外径側基部と背面が連続平坦面を有する内径方向に延伸して上記回転軸の外周面に内周端が接近する軸心直交薄肉壁部と、該軸心直交薄肉壁部の該内周端から基端が直角に折曲がって流体収納室側へ延伸する摺接リップ部を、有し；さらに、上記主シール部材と上記減圧シール部材の間に金属製平ワッシャを配設して、該金属製平ワッシャは、外周端は上記共通アウターケースに嵌着されると共に、内周端は上記回転軸の外周面に接近して対面し；かつ、上記外径側基部と上記薄肉壁部の背面の連続平坦面を、上記平ワッシャの上記外周端から内周端の範囲にて密着保持させ；しかも、上記減圧シール部材の材質をポリアミド樹脂としたものである。
【００１０】
また、本発明は、ハウジングと回転軸との間に介装されるコンプレッサ用密封装置に於て、該回転軸に摺接するシールエレメントと、該回転軸に摺接するゴム製シールリップ部を有する主シール部材と、流体収納室側に延伸する摺接リップ部を有する減圧シール部材とを、低圧室側から上記流体収納室側に順次配設して共通アウターケースによって把持固定して構成され；かつ、上記減圧シール部材は、横断面形状が軸心直交方向に細長い矩形状の外径側基部と、該外径側基部と背面が連続平坦面を有する内径方向に延伸して上記回転軸の外周面に内周端が接近する軸心直交薄肉壁部と、該軸心直交薄肉壁部の該内周端から基端が直角に折曲がって流体収納室側へ延伸する摺接リップ部を、有し；さらに、上記主シール部材と上記減圧シール部材の間に金属製平ワッシャを配設して、該金属製平ワッシャは、外周端は上記共通アウターケースに嵌着されると共に、内周端は上記回転軸の外周面に接近して対面し；かつ、上記外径側基部と上記薄肉壁部の背面の連続平坦面を、上記平ワッシャの上記外周端から内周端の範囲にて密着保持させ；しかも、上記減圧シール部材の材質をポリアミド樹脂としたものである。
【００１１】
また、共通アウターケースは、流体収納室側端部に内フランジ部を備え、さらに、上記減圧シール部材の上記外径側基部を上記内フランジ部と該平ワッシャにて挾圧されるように、上記共通アウターケースの低圧室側端部をカシメ加工にて、把持固定した。
【００１２】
【発明の実施の形態】
以下、図示の実施の形態に基づき、本発明を詳説する。
【００１３】
図１と図２は、本発明の密封装置の断面側面図を示し、図１は未装着時の自由状態を示し、図２は装着時の使用状態を示す。この密封装置は、コンプレッサのケース等のハウジング１と回転軸２との間に介装され、流体収納室10側に収納されている高圧の冷媒と潤滑剤として作用する油とを有する流体を、低圧室20側に対して、密封するものである。
【００１４】
この密封装置は、回転軸２に摺接するゴム製シールリップ部３を有する主シール部材４と、この主シール部材４よりも流体収納室10側に配設された減圧シール部材Ｓとを、共通アウターケース５によって、把持固定して、構成されている。
【００１５】
減圧シール部材Ｓは、流体収納室10側に延伸して、回転軸２の外周面に摺接する摺接リップ部６を有する。また、主シール部材４は、金属部７とゴム部８とを、接着（融着や溶着や焼付けを含む）等で一体化して構成される。
【００１６】
さらに具体的には、減圧シール部材Ｓは、その材質としてポリアミド樹脂が好ましい。つまり、射出成形等により溶融加工ができて、ＰＴＦＥ等を用いた場合よりも低コストで成形でき、さらに、流体収納室10の密封流体が液体と気体の混ざった流体であるときにも確実な漏洩防止を図り得る。
【００１７】
主シール部材４の金属部７は、円筒板部７ａと軸心直交壁部７ｂとを有した断面アングル型であって、円筒板部７ａを流体収納室10側となるように配設されている。ゴム部８は、この円筒板部７ａの外周面の大半部分を被覆する外周壁部８ａと、軸心直交壁部７ｂの両面を被覆する軸心直交壁部８ｂ，８ｃと、軸心直交壁部７ｂの内周端縁７ｃを被覆すると共に上記軸心直交壁部８ｂと軸心直交壁部８ｃとを連結する連結部８ｄと、この連結部８ｄから流体収納室10側へ延伸したシールリップ部３と、から構成されている。
【００１８】
９は、この主シール部材４を背面と内周面側から受持する断面Ｌ字状のサポート金具である。即ち、このサポート金具９は、主シール部材４のゴム部８の軸心直交壁部８ｂと、連結部８ｄとシールリップ部３を、受持して、流体収納室10側からの圧力がゴム部８に作用したときに、背面及び内周面側からサポート（受持）して、過大な変形を防止する。しかも、このサポート金具９の内周壁部９ａ先端は、緩やかな勾配面を有し、シールリップ部３がスムースに弾性変形するように、内周面側から受持している。
【００１９】
11は金属製平ワッシャであり、回転軸２の軸心Ｌと直交する平面の方向に配設された一文字型断面の円環平板部材から成る。そして、減圧シール部材Ｓは、軸心Ｌと直交する平面に一致する平坦面12を有し、この平坦面12を上記平ワッシャ11にて密着保持する。
【００２０】
さらに具体的に説明すると、主シール部材４の金属部７の円筒板部７ａの流体収納室側端部と、減圧シール部材Ｓの平坦面12との間に、平ワッシャ11を配設して、平ワッシャ11にて、減圧シール部材Ｓを背面側から密着して支持している。
【００２１】
共通アウターケース５は、流体収納室側端部に内フランジ部15を有する。かつ、この共通アウターケース５は、金属板部13とゴム部14とを備え、金属板部13は、流体収納室側内フランジ部13ａと、ハウジング１の内周面に接近して配設される円筒壁部13ｂと、カシメ加工にて最終的に折曲形成される（低圧室20側の）折曲小片部13ｃとを有する略円筒状である。また、ゴム部14は、金属板部13の円筒壁部13ｂの外周面（の流体収納室寄りの範囲）を被覆してハウジング１の内周面に嵌着状態で圧接して密封作用をなす外周密封壁部14ａと、内フランジ部13ａを被覆する断面Ｕ字状のフランジ被覆部14ｂと、から成る。
【００２２】
減圧シール部材Ｓは、横断面が軸心直交方向に細長い矩形状の外径側基部16と、この外径側基部16と背面が連続平坦面を有する内径方向に延伸した軸心直交薄肉壁部17と、この軸心直交薄肉壁部17の内周端から流体収納室10側へ延伸した前記摺接リップ部６と、から成る。
【００２３】
そして、減圧シール部材Ｓの基部16及び薄肉壁部17によって形成された軸心直交方向の（連続状の）平坦面12を、平ワッシャ11に密着させ、かつ、減圧シール部材Ｓの基部16の流体収納室側平坦面18を、共通アウターケース５の内フランジ部15（のゴム部14のフランジ被覆部14ｂの内壁）に密着させるようにして、共通アウターケース５の低圧室側端部（の折曲小片部13ｃ）のカシメ加工にて把持されている。つまり、減圧シール部材Ｓの外径側基部16を、内フランジ部15と平ワッシャ11にて、挾圧されるように、共通アウターケース５のカシメ加工で、主シール部材４、サポート金具９等と共に、把持固定されて、組立てられている。
【００２４】
また、19はシールエレメントであり、サポート金具９の背面側に配設され、金属製インナーケース21によってこのシールエレメント19はさらに背面側から挾持されている。このインナーケース21は直接に、共通アウターケース５の折曲小片部13ｃに接触し、カシメ加工の押圧力を受ける。
【００２５】
シールエレメント19は、螺旋状切込溝22を有し、例えば、ＰＴＦＥ樹脂製であり、回転軸２が回転すると、ポンピング作用により、流体を流体収納室10の方向へ押し返す。また、このシールエレメント19は、自然状態では円環平板状であり、内径側を流体収納室10側に向けて屈曲させつつ回転軸２を挿入する。回転軸２とは所定幅で接する摺接面を形成する。
【００２６】
このように、図１と図２に示した実施の形態の密封装置は、インナーケース21、シールエレメント19、サポート金具９、ゴム製シールリップ部３を有する主シール部材４、平ワッシャ11、摺接リップ部６を有する減圧シール部材Ｓを、低圧室20側から流体収納室10側に順次配設して、共通アウターケース５によって（その折曲小片部13ｃのカシメ加工によって）把持固定して、一体化した構成である。
【００２７】
なお、主シール部材４のゴム部８の外周壁部８ａに於て、その外周面を凹凸波型として、アウターケース５に嵌合させたときに、圧入状態として、その凹凸波型の（２点鎖線にて示した）凸波部は弾性圧縮変形することにより、この嵌合面からの流体の漏洩を防ぐ。なお、ゴム部14の外周密封壁部14ａとハウジング１の内周面との嵌合面部位も同様の構造とする。
【００２８】
次に、本発明の密封装置におけるシール機能について説明すると、流体収納室10で（冷媒と油等からなる）流体が高圧に保たれると、内フランジ部15と平ワッシャ11により安定して姿勢保持されている減圧シール部材Ｓの摺接リップ部６がその圧力を受けて、摺接リップ部６が回転軸２の外周面に押圧する力が大きくなって、シール力が増大するため、流体収納室10の流体の高い圧力が主シール部材４にそのまま作用することがない。
【００２９】
さらに、減圧シール部材Ｓの材質をポリアミド樹脂としたので、減圧シール部材Ｓにおける流体収納室10からの流体漏れは、ほとんど油（液体）のみとすることができ、この漏れ油が減圧シール部材Ｓの摺接リップ部６の接触面と回転軸２との間に介在し、潤滑効果を兼ねることができる。そして、この油は後方の主シール部材４のシールリップ部３によりシールされる。
【００３０】
また、主シール部材４においては、平ワッシャ11との間に形成された減圧室（中間空室部）23の流体は、シールリップ部３とシールエレメント19とによりシールされることとなる。即ち、シールエレメント19は、シールエレメント19の摺接面に設けた螺旋状の切込溝22により、回転軸２が回転すると、ハイドロダイナミック効果（ポンピング作用）を引き起し、シールエレメント19の摺接面と回転軸２との間の油を減圧室23側に押し戻すため、流体（油）が（大気側の）低圧室20に漏れることがない。
【００３１】
また、本発明は上述の図示の実施の形態に限定されず、設計変更自由である。例えば、主シール部材４の後方にサポート金具９がないものとしたり、また、シールリップ部３やシールエレメント19を２枚以上配設したり、シールエレメント19の摺接面に設ける切込溝22を、同心円状の独立溝としてもよい。また、金属部７、インナーケース21の形状と結合構造等も種々変形自由である。さらに、場合によっては、低圧室20側に副シール部材を追加して、中間空室部23を２個並設しても、自由である。そして、いずれにせよ、共通アウターケース５によって、全体を一体状に把持固定する。
【００３２】
【実施例】
図１と図２に示した形状と構造を備えたものであって、減圧シール部材Ｓの材質をノナンジアミン−テレフタル酸共重合体（株式会社クラレ製ＰＡ９Ｔ）を使用した密封装置を、本発明の実施例とする。
【００３３】
比較例として、図５に示すように、ハウジング41に流体収納室側凹周溝26と、中間凹周溝27を形成し、その間に区画壁部28を形成して、回転軸42を挿入し、さらに、流体収納室側凹周溝26に同じ材質のコの字状の減圧シール部材29を嵌着した。他方、中間凹周溝27には、主シール部材30を一体に有するアウターケース31内に、サポート金具32と、切込溝33を有するシールエレメント34とインナーケース35を、把持固定したシール39を、嵌着したものを、採用した。言い換えると、本発明実施例（図１，図２）のものを、２分割して、装着した構造である。
【００３４】
従来例として、図４の構造のもの（既に説明済み）を採用した。即ち、本発明実施例の減圧シール部材Ｓや、図５に示した比較例のコ字状の減圧シール部材29を、省略した、回転軸シール43Ａのみから成る。
【００３５】
上述の実施例（図１，図２）と、比較例（図５）と、従来例（図４）の各密封装置について、回転耐久試験を行った。その結果を次の表１に示す。なお、表１中に於て、取付部の大きさは、（嵌着孔部の径）×（軸心方向寸法）をもって示す。
【００３６】
【表１】

【００３７】
上記表１から、実施例と比較例は 200時間経過しても漏れを発生せず、従来例よりも優れた耐久シール性を発揮する。このように、実施例と比較例では、回転軸２，42と摺接するシールリップ部３（主シール部材30のシールリップ部）の摩耗や過度の発熱発生もなく、減圧シール部材Ｓ，29の減圧効果が発揮されたことがわかる。
【００３８】
しかし、比較例（図５）では取付ける際に、２個の部品───シール39及び減圧シール部材29───を装着する作業上の面倒さがあり、かつ、ハウジング41自体も複雑な孔形状（２箇所の凹周溝27及び凹周溝26を要する形状）とせねばならないという欠点が残っている。さらに言えば、比較例（図５）では、治具作成時や装着時に、偏心等の不具合を生じる虞があり、シールの信頼性もやや低下するという問題がある。そして、ハウジング41が軸心方向に長くなり、装置全体の小型化・コンパクト化を、阻害するという欠点もある。
【００３９】
これに対し、本発明（実施例）では、減圧シール部材Ｓが一体構造化され、装着作業性に優れ、ハウジング１の孔部の形状もシンプルで済み、軸心Ｌ方向の寸法も減少できて、小型化・コンパクト化を図り得るという著大な効果を奏する。
【００４０】
【発明の効果】
本発明によれば、共通アウターケース５によって密封装置が一体化され、取扱易く、ハウジング１へ装着し易く、作業性に優れ、特に、軸心方向Ｌに小型化を図り得て、ハウジング１自体の軸心方向寸法を短縮可能となり、かつ、ハウジング１の孔部の形状も簡素な形状で済む。かつ、平坦面12を平ワッシャ11の平坦面で受けるので、減圧シール部材Ｓの姿勢と位置が安定して維持される。これによって、回転軸２の外周面に摺接リップ部６が高精度の締め代をもって密封作用をなし、偏摩耗や異常発熱等を防止できて、寿命も延びる。
【００４１】
そして、減圧シール部材Ｓによって、流体収納室10側から作用する高圧を、直接にゴム製シールリップ部３に作用することを防いで、このゴム製シールリップ部３の回転密封性及び回転耐久性を著しく向上できる。特に、（減圧シール部材Ｓをポリアミド樹脂としたことにより、）射出成形等の溶融加工にて、少ない工程で材料ロスを生じないで、低コストで量産できる。そして、特に、ＣＯ₂等の気体を遮断して、カーエアコン用コンプレッサ等の密封装置として好適である。そして、摺接リップ部６として、減圧シールとして直接的に流体収納室10からの圧力変動に耐える剛性と強度を、確保できる。
【００４２】
（請求項２によれば、）さらに、シールエレメント19は回転軸２の回転時にハイドロダイナミック効果にて流体漏れを確実に防止し、ゴム製シールリップ部３は回転時及び静止時の流体漏れを防止するが、減圧シール部材Ｓは、これ等のシール性及び耐久性を向上させる役目をなす。
【００４３】
（請求項３によれば、）一層のコンパクト化を図り得る。さらに、高い密封性を保ちつつ、組付も容易で簡素化を図り得る。
【図面の簡単な説明】
【図１】本発明の密封装置の実施の一形態を示す自由状態における断面側面図である。
【図２】密封装置の装着状態を示す断面側面図である。
【図３】従来例の断面図である。
【図４】別の従来例の断面図である。
【図５】比較例を示す断面図である。
【符号の説明】
Ｓ減圧シール部材
１ハウジング
２回転軸
３シールリップ部
４主シール部材
５アウターケース
６摺接リップ部
10 流体収納室
11 平ワッシャ
12 平坦面
15 内フランジ部
16 外径側基部
17 軸心直交薄肉壁部
19 シールエレメント
20 低圧室[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealing device such as a compressor for a car air conditioner, and more particularly to a sealing device corresponding to a compressor whose sealing fluid has a high pressure and a rotating shaft rotates at a high speed.
[0002]
[Prior art]
A rotary shaft seal has been conventionally used as a sealing device for preventing a fluid in a fluid storage chamber in a car air conditioner compressor, that is, a mixture of oil acting as a refrigerant and a lubricant, from leaking from the sliding surface of the rotary shaft. Yes. In recent years, it has been studied to limit the use of Freon (HFC134a) as a refrigerant in global warming countermeasures, and carbon dioxide (CO ₂ ) has attracted attention as a candidate for the next-generation refrigerant, and development of a compressor using CO ₂ Is underway. However, when CO ₂ is used as the refrigerant, the fluid pressure of the compressor becomes 10 times higher than when HFC134a is used, and it is desired to develop a sealing device that can cope with this high pressure.
[0003]
As a sealing device for sealing a conventional refrigerant, a device as shown in FIG. 3 is used. This sealing device includes a rotary shaft seal 43 interposed between a housing 41 such as a compressor and a rotary shaft 42, and seals a fluid made up of refrigerant and oil in the fluid storage chamber 44. The rotary shaft seal 43 includes a rubber seal member 46 bonded to an outer case 45, and a seal element 47 made of a resin (particularly PTFE) in which a cut groove 49 is formed in a sliding contact surface that is in sliding contact with the rotary shaft 42. And the metal fitting (inner case) 48 are caulked to the outer case 45 and integrated (gripping and fixing).
[0004]
Further, the rotary shaft seal 43 seals the tip of the seal member 46 against the surface of the rotary shaft 42. However, when the rotary shaft 42 rotates, the rotary shaft seal 43 is not completely sealed, and a small amount of fluid leaks. The leaked fluid is sealed by the seal element 47, and the seal member 46 and the seal element 47 constitute a structure that prevents the fluid from leaking as the entire rotary shaft seal 43. That is, a small amount of leaked fluid is pushed back to the fluid storage chamber 44 by the spiral cut groove 49 provided on the sliding contact surface of the seal element 47 through the seal member 46, thereby sealing the rotary shaft seal 43 as a whole. Plays a function.
[0005]
[Problems to be solved by the invention]
However, when CO ₂ is used as a refrigerant, the fluid storage chamber 44 becomes high pressure, so that the rubber seal member 46 receives an excessive pressing force and the sliding contact portion of the seal member 46 is strongly pressed against the rotating shaft 42, so that wear occurs. -Heat generation was promoted, and the tip end portion (sliding contact portion) of the rubber seal member 46 was cured, causing cracks. Furthermore, the seal member 46 presses the seal element 47 in the direction of the rotating shaft 42 more than necessary due to the high pressure, heat due to friction is high, wear of the seal element 47 increases, and the durability of the seal itself is deteriorated. It was.
[0006]
Further, as described above, the rotary shaft seal 43 is configured to intentionally leak a small amount of fluid from the seal member 46, and the oil of the leaked fluid is used as a lubricant for the seal member 46 and the seal element 47. If the seal member 46 is pressed against the rotary shaft 42 more than expected due to the high pressure, no fluid is supplied to the seal element 47 and the wear of the seal member 46 and the seal element 47 is promoted, and the rotary shaft seal 43 is designed. There was a problem that it did not work.
[0007]
In order to cope with the high pressure of the refrigerant (sealing fluid) described above, a sealing device (rotary shaft seal 43A) as shown in FIG. 4 has been proposed. That is, the back-up metal fitting 51 that holds the rubber seal member 46 from the back is added.
However, it has been found that the conventional rotary shaft seal 43A shown in FIG. 4 is insufficient in terms of durability for the same reason as described above against the recent high-pressure refrigerant (sealing fluid).
[0008]
Accordingly, the present invention provides a sealing device that improves the durability of the rotary shaft seal by suppressing the acceleration of wear caused by the high-pressure fluid, reducing the heat generated by frictional heat, etc. The purpose is to provide. It is another object of the present invention to provide a reliable sealing device that maintains good mounting workability between the housing and the rotating shaft, and that is downsized.
[0009]
[Means for Solving the Problems]
In order to achieve the above-described object, the present invention provides a compressor sealing device interposed between a housing and a rotary shaft, and a main seal member having a rubber seal lip portion slidably contacting the rotary shaft. A pressure reducing seal member having a sliding contact lip portion that is disposed closer to the fluid storage chamber than the main seal member and extends toward the fluid storage chamber is held and fixed by a common outer case; and The decompression seal member has a rectangular outer diameter side base having a cross-sectional shape elongated in the direction perpendicular to the axial center, and the outer diameter side base and the back surface extend in the inner diameter direction having a continuous flat surface, and extend to the outer peripheral surface of the rotating shaft. the axis orthogonal thin wall portion whose inner peripheral end approaches the sliding lip portion proximal from the inner peripheral end of the shaft center orthogonal thin wall portion extends bent at right angles to the fluid storing chamber side, has Further, gold is interposed between the main seal member and the vacuum seal member. A flat washer is provided, and the metal flat washer has an outer peripheral end fitted into the common outer case, and an inner peripheral end facing the outer peripheral surface of the rotating shaft and facing; and A continuous flat surface of the outer diameter side base portion and the back surface of the thin wall portion is closely held in a range from the outer peripheral end to the inner peripheral end of the flat washer; and the material of the vacuum seal member is a polyamide resin It is.
[0010]
In the compressor sealing device interposed between the housing and the rotating shaft, the present invention includes a seal element that is in sliding contact with the rotating shaft, and a rubber seal lip portion that is in sliding contact with the rotating shaft. A seal member and a decompression seal member having a sliding lip portion extending toward the fluid storage chamber are sequentially disposed from the low pressure chamber side to the fluid storage chamber side and are held and fixed by a common outer case; and The decompression seal member has an outer diameter side base portion having a rectangular cross-sectional shape elongated in the direction perpendicular to the axis, and the outer diameter side base portion and the back surface extending in the inner diameter direction having a continuous flat surface, and the outer periphery of the rotating shaft. An axially orthogonal thin wall portion whose inner peripheral end approaches the surface, and a sliding contact lip portion whose base end is bent at a right angle from the inner peripheral end of the axially orthogonal thin wall portion and extends toward the fluid storage chamber. The main seal member and the vacuum seal A metal flat washer is disposed between the materials, and the metal flat washer has an outer peripheral end fitted into the common outer case, and an inner peripheral end facing the outer peripheral surface of the rotating shaft. And holding the continuous flat surface of the outer diameter side base portion and the back surface of the thin wall portion in a range from the outer peripheral end to the inner peripheral end of the flat washer; It is a polyamide resin.
[0011]
Further, the common outer case includes an inner flange portion at an end portion on the fluid storage chamber side, and further, the outer diameter side base portion of the decompression seal member is pressed by the inner flange portion and the flat washer. The end portion on the low pressure chamber side of the common outer case was held and fixed by caulking.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on the illustrated embodiment.
[0013]
1 and 2 are sectional side views of the sealing device of the present invention, FIG. 1 shows a free state when not mounted, and FIG. 2 shows a used state when mounted. This sealing device is interposed between a housing 1 such as a compressor case and a rotating shaft 2, and contains a fluid having a high-pressure refrigerant stored in the fluid storage chamber 10 and oil acting as a lubricant. The low pressure chamber 20 side is sealed.
[0014]
In this sealing device, a main seal member 4 having a rubber seal lip portion 3 slidably contacting the rotating shaft 2 and a decompression seal member S disposed closer to the fluid storage chamber 10 than the main seal member 4 are shared. The outer case 5 is configured to be held and fixed.
[0015]
The decompression seal member S has a sliding contact lip portion 6 that extends toward the fluid storage chamber 10 and comes into sliding contact with the outer peripheral surface of the rotary shaft 2. The main seal member 4 is configured by integrating the metal portion 7 and the rubber portion 8 by bonding (including fusion, welding, and baking) or the like.
[0016]
More specifically, the decompression seal member S is preferably made of polyamide resin. That is, it can be melt-processed by injection molding or the like, can be molded at a lower cost than when PTFE or the like is used, and moreover, it is reliable even when the sealing fluid in the fluid storage chamber 10 is a fluid mixture of liquid and gas. Leakage prevention can be achieved.
[0017]
The metal portion 7 of the main seal member 4 is an angle section having a cylindrical plate portion 7a and an axial center orthogonal wall portion 7b, and is disposed so that the cylindrical plate portion 7a is on the fluid storage chamber 10 side. Yes. The rubber portion 8 includes an outer peripheral wall portion 8a that covers most of the outer peripheral surface of the cylindrical plate portion 7a, axial center

orthogonal wall portions

8b and 8c that cover both surfaces of the axial center orthogonal wall portion 7b, and an axial center orthogonal wall. A connecting portion 8d that covers the inner peripheral edge 7c of the portion 7b and connects the axially orthogonal wall portion 8b and the axially orthogonal wall portion 8c, and a seal lip extending from the connecting portion 8d toward the fluid storage chamber 10 Part 3.
[0018]
Reference numeral 9 denotes a support fitting having an L-shaped cross section for receiving the main seal member 4 from the back surface and the inner peripheral surface side. That is, the support fitting 9 receives the axially orthogonal wall portion 8b of the rubber portion 8 of the main seal member 4, the connecting portion 8d, and the seal lip portion 3 so that the pressure from the fluid storage chamber 10 side is rubber. When acting on the portion 8, it is supported (received) from the back surface and the inner peripheral surface side to prevent excessive deformation. Moreover, the tip of the inner peripheral wall portion 9a of the support fitting 9 has a gently inclined surface, and is supported from the inner peripheral surface side so that the seal lip portion 3 can be elastically deformed smoothly.
[0019]
Reference numeral 11 denotes a metal flat washer, which is formed of a circular plate member having a single-character cross section disposed in a plane direction orthogonal to the axis L of the rotating shaft 2. The decompression seal member S has a flat surface 12 that coincides with a plane orthogonal to the axis L, and this flat surface 12 is held tightly by the flat washer 11.
[0020]
More specifically, a flat washer 11 is disposed between the fluid storage chamber side end of the cylindrical plate portion 7a of the metal portion 7 of the main seal member 4 and the flat surface 12 of the decompression seal member S. The decompression seal member S is supported in close contact with the flat washer 11 from the back side.
[0021]
The common outer case 5 has an inner flange portion 15 at the end portion on the fluid storage chamber side. The common outer case 5 includes a metal plate portion 13 and a rubber portion 14. The metal plate portion 13 is disposed close to the fluid storage chamber side inner flange portion 13a and the inner peripheral surface of the housing 1. The cylindrical wall portion 13b and the bent small piece portion 13c (on the low pressure chamber 20 side) that is finally bent by caulking are formed in a substantially cylindrical shape. Further, the rubber part 14 covers the outer peripheral surface of the cylindrical wall part 13b of the metal plate part 13 (a range close to the fluid storage chamber) and press-contacts with the inner peripheral surface of the housing 1 in a fitted state to form a sealing action. It comprises an outer peripheral sealing wall portion 14a and a flange covering portion 14b having a U-shaped cross section that covers the inner flange portion 13a.
[0022]
The decompression seal member S has a rectangular outer diameter side base portion 16 whose cross section is elongated in the direction orthogonal to the axial center, and an axially orthogonal thin wall portion extending in the inner diameter direction, the outer diameter side base portion 16 and the back surface having a continuous flat surface. 17 and the sliding contact lip portion 6 extending from the inner peripheral end of the axially orthogonal thin wall portion 17 to the fluid storage chamber 10 side.
[0023]
Then, a flat surface 12 in a direction orthogonal to the axial center formed by the base portion 16 and the thin wall portion 17 of the decompression seal member S is brought into close contact with the flat washer 11, and the base portion 16 of the decompression seal member S is The fluid storage chamber side flat surface 18 is brought into close contact with the inner flange portion 15 of the common outer case 5 (the inner wall of the flange covering portion 14b of the rubber portion 14). The bent small piece portion 13c) is gripped by caulking. That is, the main seal member 4, the support fitting 9, and the like are obtained by caulking the common outer case 5 so that the outer diameter side base portion 16 of the decompression seal member S is pressed by the inner flange portion 15 and the flat washer 11. At the same time, it is held and fixed and assembled.
[0024]
Reference numeral 19 denotes a seal element, which is disposed on the back side of the support fitting 9 and is further clamped from the back side by a metal inner case 21. The inner case 21 directly contacts the bent piece 13c of the common outer case 5 and receives a pressing force for caulking.
[0025]
The seal element 19 has a spiral cut groove 22 and is made of, for example, PTFE resin. When the rotary shaft 2 rotates, the fluid is pushed back toward the fluid storage chamber 10 by a pumping action. The seal element 19 is an annular flat plate in a natural state, and the rotating shaft 2 is inserted while the inner diameter side is bent toward the fluid storage chamber 10 side. A sliding contact surface that is in contact with the rotating shaft 2 with a predetermined width is formed.
[0026]
As described above, the sealing device of the embodiment shown in FIGS. 1 and 2 includes the inner case 21, the seal element 19, the support fitting 9, the main seal member 4 having the rubber seal lip portion 3, the flat washer 11, the slide. The decompression seal member S having the contact lip portion 6 is sequentially arranged from the low pressure chamber 20 side to the fluid storage chamber 10 side, and is held and fixed by the common outer case 5 (by caulking of the bent small piece portion 13c). This is an integrated configuration.
[0027]
In the outer peripheral wall 8a of the rubber portion 8 of the main seal member 4, the outer peripheral surface of the main seal member 4 is an uneven corrugated shape, and when the outer seal is fitted to the outer case 5, the concave and convex corrugated (2 The convex wave portion (shown by a dotted line) is elastically deformed to prevent fluid leakage from the fitting surface. The fitting surface portion between the outer peripheral sealing wall portion 14a of the rubber portion 14 and the inner peripheral surface of the housing 1 has the same structure.
[0028]
Next, the sealing function of the sealing device of the present invention will be described. When the fluid (consisting of refrigerant and oil) is kept at a high pressure in the fluid storage chamber 10, the inner flange portion 15 and the flat washer 11 stabilize the posture. Since the sliding contact lip portion 6 of the pressure-reducing seal member S being held receives the pressure, the force with which the sliding contact lip portion 6 presses against the outer peripheral surface of the rotating shaft 2 increases, and the sealing force increases. The high pressure of the fluid in the storage chamber 10 does not act on the main seal member 4 as it is.
[0029]
Further, since the material of the decompression seal member S is made of polyamide resin, fluid leakage from the fluid storage chamber 10 in the decompression seal member S can be almost oil (liquid). It is interposed between the contact surface of the sliding contact lip portion 6 and the rotary shaft 2 and can also serve as a lubricating effect. This oil is sealed by the seal lip portion 3 of the rear main seal member 4.
[0030]
In the main seal member 4, the fluid in the decompression chamber (intermediate empty chamber portion) 23 formed between the flat washer 11 is sealed by the seal lip portion 3 and the seal element 19. That is, the seal element 19 causes a hydrodynamic effect (pumping action) when the rotary shaft 2 rotates by the spiral cut groove 22 provided on the sliding contact surface of the seal element 19, and the seal element 19 slides. Since the oil between the contact surface and the rotary shaft 2 is pushed back to the decompression chamber 23 side, the fluid (oil) does not leak into the low pressure chamber 20 (at the atmosphere side).
[0031]
Further, the present invention is not limited to the above-described illustrated embodiment, and can be freely changed in design. For example, the support metal fitting 9 is not provided behind the main seal member 4, or two or more seal lip portions 3 or seal elements 19 are provided, or a cut groove 22 provided on the sliding contact surface of the seal element 19. May be concentric independent grooves. Further, the shape of the metal part 7 and the inner case 21, the coupling structure, and the like can be variously modified. Furthermore, depending on the case, it is also possible to add a secondary seal member on the low pressure chamber 20 side and arrange two intermediate vacant chambers 23 side by side. In any case, the entire outer case 5 is held and fixed integrally.
[0032]
【Example】
A sealing device having the shape and structure shown in FIG. 1 and FIG. 2, and using a nonanediamine-terephthalic acid copolymer (PA9T manufactured by Kuraray Co., Ltd.) as the material of the vacuum seal member S. Example.
[0033]
As a comparative example, as shown in FIG. 5, a fluid storage chamber side concave circumferential groove 26 and an intermediate concave circumferential groove 27 are formed in a housing 41, a partition wall portion 28 is formed therebetween, and a rotating shaft 42 is inserted. Furthermore, a U-shaped decompression seal member 29 made of the same material was fitted into the concave groove 26 on the fluid storage chamber side. On the other hand, the intermediate concave circumferential groove 27 is provided with a seal 39 holding and fixing a support fitting 32, a sealing element 34 having a cut groove 33, and an inner case 35 in an outer case 31 integrally having a main seal member 30. The one that was fitted was used. In other words, the embodiment of the present invention (FIGS. 1 and 2) is divided into two and mounted.
[0034]
As a conventional example, the structure shown in FIG. 4 (already described) was adopted. In other words, the pressure reducing seal member S of the embodiment of the present invention and the U-shaped pressure reducing seal member 29 of the comparative example shown in FIG.
[0035]
A rotation durability test was performed on each of the sealing devices of the above-described examples (FIGS. 1 and 2), the comparative example (FIG. 5), and the conventional example (FIG. 4). The results are shown in Table 1 below. In Table 1, the size of the mounting portion is indicated by (diameter of fitting hole portion) × (axis direction dimension).
[0036]
[Table 1]

[0037]
From Table 1 above, the Examples and Comparative Examples do not leak even after 200 hours, and exhibit superior durability sealability than the conventional examples. As described above, in the example and the comparative example, there is no wear of the seal lip portion 3 (seal lip portion of the main seal member 30) slidably contacting the

rotary shafts

2 and 42, and excessive heat generation is not caused. It can be seen that the decompression effect was exhibited.
[0038]
However, in the comparative example (FIG. 5), there are troublesome work in mounting two parts --- the seal 39 and the pressure-reducing seal member 29--when mounting, and the housing 41 itself has a complicated hole. The drawback remains that it must have a shape (a shape requiring two concave grooves 27 and 26). Furthermore, in the comparative example (FIG. 5), there is a possibility that problems such as eccentricity may occur when a jig is created or mounted, and there is a problem that the reliability of the seal is slightly lowered. Further, the housing 41 is elongated in the axial direction, and there is a drawback that the downsizing and downsizing of the entire apparatus is hindered.
[0039]
On the other hand, in the present invention (Example), the decompression seal member S is integrated, excellent in mounting workability, the shape of the hole portion of the housing 1 is simple, and the dimension in the axis L direction can be reduced. It has a remarkable effect that it can be reduced in size and size.
[0040]
【The invention's effect】
According to the present invention, the sealing device is integrated by the common outer case 5 and is easy to handle, easy to attach to the housing 1, excellent in workability, and in particular, can be downsized in the axial direction L, and the housing 1 itself The axial dimension of the housing 1 can be shortened, and the shape of the hole of the housing 1 can be simple. In addition, since the flat surface 12 is received by the flat surface of the flat washer 11, the posture and position of the decompression seal member S are stably maintained. As a result, the sliding contact lip 6 on the outer peripheral surface of the rotary shaft 2 has a high-accuracy tightening allowance, and can prevent uneven wear and abnormal heat generation, thereby extending the life.
[0041]
Then, the decompression seal member S prevents the high pressure acting from the fluid storage chamber 10 side from directly acting on the rubber seal lip portion 3, and the rotational sealability and rotational durability of the rubber seal lip portion 3 are prevented. Can be significantly improved. In particular, by using a polyamide resin as the decompression seal member S, mass production can be performed at low cost without causing material loss in a small number of steps in melt processing such as injection molding. In particular, it is suitable as a sealing device for a car air conditioner compressor by blocking gas such as CO ₂ . Further, the sliding contact lip portion 6 can ensure rigidity and strength that can withstand pressure fluctuations directly from the fluid storage chamber 10 as a reduced pressure seal.
[0042]
(According to claim 2) Furthermore, the sealing element 19 reliably prevents fluid leakage by the hydrodynamic effect when the rotary shaft 2 rotates, and the rubber seal lip 3 prevents fluid leakage during rotation and at rest. The pressure reducing seal member S serves to improve the sealing performance and durability.
[0043]
(According to claim 3), it is possible to further reduce the size. Furthermore, assembly can be facilitated and simplified while maintaining high sealing performance.
[Brief description of the drawings]
FIG. 1 is a cross-sectional side view in a free state showing an embodiment of a sealing device of the present invention.
FIG. 2 is a sectional side view showing a mounting state of the sealing device.
FIG. 3 is a cross-sectional view of a conventional example.
FIG. 4 is a cross-sectional view of another conventional example.
FIG. 5 is a cross-sectional view showing a comparative example.
[Explanation of symbols]
S Pressure reducing seal member 1 Housing 2 Rotating shaft 3 Seal lip portion 4 Main seal member 5 Outer case 6 Sliding contact lip portion
10 Fluid storage room
11 Flat washer
12 Flat surface
15 Inner flange
16 Outer diameter side base
17 Axial orthogonal thin wall
19 Seal element
20 Low pressure chamber

Claims

In a compressor sealing device interposed between a housing and a rotating shaft, a main seal member having a rubber seal lip portion slidably contacting the rotating shaft, and a fluid storage chamber side of the main seal member. A pressure reducing seal member having a sliding contact lip portion which is provided and extends toward the fluid storage chamber, and is configured to be held and fixed by a common outer case,
The decompression seal member has an outer diameter side base portion having a rectangular cross-sectional shape that is elongated in the direction perpendicular to the axis, and the outer diameter side base portion and the back surface extend in the inner diameter direction having a continuous flat surface. An axially orthogonal thin wall portion whose inner peripheral end approaches the outer peripheral surface, and a sliding contact lip portion whose base end is bent at a right angle from the inner peripheral end of the axially orthogonal thin wall portion and extends toward the fluid storage chamber. Have
Furthermore, a metal flat washer is disposed between the main seal member and the decompression seal member, and the metal flat washer has an outer peripheral end fitted into the common outer case, and an inner peripheral end of the metal flat washer. Approach the outer peripheral surface of the rotating shaft and face each other
And the continuous flat surface of the back surface of the outer diameter side base and the thin wall portion is tightly held in the range from the outer peripheral end to the inner peripheral end of the flat washer,
Moreover, the sealing device is characterized in that the pressure reducing seal member is made of a polyamide resin.

In a compressor sealing device interposed between a housing and a rotating shaft, a seal element that is in sliding contact with the rotating shaft, a main seal member having a rubber seal lip portion that is in sliding contact with the rotating shaft, and fluid storage A decompression seal member having a sliding contact lip portion extending to the chamber side is configured by being sequentially disposed from the low pressure chamber side to the fluid storage chamber side and held and fixed by a common outer case,
The decompression seal member has an outer diameter side base portion having a rectangular cross-sectional shape that is elongated in the direction perpendicular to the axis, and the outer diameter side base portion and the back surface extend in the inner diameter direction having a continuous flat surface. An axially orthogonal thin wall portion whose inner peripheral end approaches the outer peripheral surface, and a sliding contact lip portion whose base end is bent at a right angle from the inner peripheral end of the axially orthogonal thin wall portion and extends toward the fluid storage chamber. Have
Furthermore, a metal flat washer is disposed between the main seal member and the decompression seal member, and the metal flat washer has an outer peripheral end fitted into the common outer case, and an inner peripheral end of the metal flat washer. Approach the outer peripheral surface of the rotating shaft and face each other
And the continuous flat surface of the back surface of the outer diameter side base and the thin wall portion is tightly held in the range from the outer peripheral end to the inner peripheral end of the flat washer,
Moreover, the sealing device is characterized in that the pressure reducing seal member is made of a polyamide resin.

The common outer case is provided with an inner flange portion at the end portion on the fluid storage chamber side, and further, the common outer case is pressed against the outer diameter side base portion of the decompression seal member by the inner flange portion and the flat washer. The sealing device according to claim 1 or 2, wherein the end portion of the outer case on the low pressure chamber side is held and fixed by caulking.