JP3810919B2

JP3810919B2 - Dust seal for constant velocity universal joint

Info

Publication number: JP3810919B2
Application number: JP07595498A
Authority: JP
Inventors: 健太山崎; 哲郎門田
Original assignee: NTN Corp
Current assignee: NTN Corp
Priority date: 1998-03-24
Filing date: 1998-03-24
Publication date: 2006-08-16
Anticipated expiration: 2018-03-24
Also published as: JPH11270575A

Description

【０００１】
【発明の属する技術分野】
本発明は、自動車や各種産業機械で使用される等速自在継手を被覆して継手内へのダスト類の侵入防止と継手内のグリース等の漏洩を防止するダストシールに関する。
【０００２】
【従来の技術】
二軸間の角度変位を許容する固定型等速自在継手の内部グリースの漏洩防止と外部ダストの侵入防止の目的で装着される蛇腹形状のブーツは、外側継手部材に対するシャフトの作動角が大きくなると蛇腹同士が干渉して耐久性低下に到ることがある。そこで、大きな作動角で使用される固定型等速自在継手においては、外側継手部材を包み込む球体構造のダストシールが蛇腹形ブーツに代わり使用される傾向にある。
【０００３】
かかるダストシールは、本出願人の先願である特開平２−２７８０１６号公報等に開示されているように、固定型等速自在継手の外側継手部材の外周とシャフトの外周に両端部が嵌着された椀状の球体を基本構造とする。この椀状球体は単層或いは複層構造のもので、その中央部に形成した円筒部がシャフトにバンド締め等で固定され、円筒部から椀状に延在する球状内面の開口部分が外側継手部材の外周に摺動可能に嵌着される。また、球体と外側継手部材の間には外側継手部材外周から球体内にダスト類の侵入を防止するダストシール部品や、球体内から外側継手部材外周へのグリースの漏洩を防止するグリースシール部品、これらシール部品を良好な状態に維持させるための別部品が組込まれる。更に、球体と各種シール部品を外側継手部材とシャフトに取付けるための各種取付部品が使用されて、耐久性とシール機能に優れたダストシールが構成され、実用化されている。
【０００４】
【発明が解決しようとする課題】
上記ダストシールは、継手内へのダスト侵入と継手外へのグリース漏洩を防止するシール性と、外側継手部材に対してシャフトの作動角が大きくなっても摩損の可能性が少なくて耐久性に優れることから、大きな作動角で使用される固定型等速自在継手に高信頼製品として実用化されている。しかし、高シール性や高耐久性を達成するために部品点数が多くなってダストシール自体の原価低減化が難しく、また、構造が複雑化して等速自在継手への組付工数が多くなり、ダストシール付等速自在継手の製造コストの低減化を難しくしている。
【０００５】
本発明の目的は、部品点数を少なくして原価低減化を容易にし、等速自在継手への組付性を改善した等速自在継手用ダストシールを提供することにある。
【０００６】
【課題を解決するための手段】
上記目的を達成する本発明の技術的手段は、等速自在継手の外側継手部材の円筒外周面に嵌着される円筒状内面、及び、等速自在継手のジョイント中心を中心とする凸球状外面を有する内シール部材と、内シール部材の凸球状外面と同一中心の球面で内シール部材の凸球状外面に摺接可能に被嵌される凹球状内面、及び、この凹球状内面と同一中心の凸球状外面、及び、中央部に等速自在継手のシャフトに嵌着されてシールするシール穴部を有する可撓性の中間シール部材と、中間シール部材の凸球状外面に一体的に被嵌される凹球状内面と、中央部に等速自在継手のシャフトに嵌着された中間シール部材のシール穴部を被覆してシャフトに嵌着されるシール筒部を有する椀状の外シール部材で構成したことにある。
【０００７】
中間シール材は、ゴムや軟質樹脂のようなシール性に適した可撓性材料からなる椀状のもので、外シール部材と一体的に等速自在継手のシャフトに取付けられる。シャフトが外側継手部材に対してジョイント中心を中心に角度変位すると、中間シール部材はシャフト及び外シール部材に伴って角度変位し、外側継手部材に固定された内シール部材の凸球状外面に常時摺接して、継手内部をシールする。
【０００８】
内シール部材と外シール部材の少なくとも一方を可撓性材料で形成することにより、中間シール部材に被嵌した外シール部材を中間シール部材を介して内シール部材に被嵌するときに、内シール部材と外シール部材の一方あるいは両方を弾性変形させて内外両シール部材を組付けることができる。そのため、ダストシール自体の組付性、さらにはこのダストシールの等速自在継手への組付性が良好なものになる。ここでの可撓性材料としては、例えばプラスチック、ゴム、薄肉金属を用いることができる。
【０００９】
外シール部材のシール筒部に、等速自在継手のシャフトに中間シール部材のシール穴部を嵌挿する際のシール穴部の弾性変形部位の逃げ用凹部を形成すると良い。このようにすることで、等速自在継手のシャフトに中間シール部材のシール穴部を弾性変形させて弾圧的に嵌挿することが容易になり、中間シール部材のシール穴部をシャフトに弾圧的に高シール性で嵌着することが容易になる。
【００１０】
また、外シール部材のシール筒部に、逃げ用凹部とシャフト及び中間シール部材との間に形成される空隙の空気を逃がす空気抜き穴を形成すると良い。このようにすることで、等速自在継手のシャフトに中間シール部材のシール穴部を嵌挿する際の作業が容易になる。
【００１１】
中間シール部材のシール穴部と等速自在継手のシャフトとの密着性を高めるため、シール穴部にシール補強手段を付設しても良い。このシール補強手段として、シール穴部を部分的に厚肉に形成する手段や、シール穴部を外径側から弾圧的に締付けるスプリング手段を採用することができる。
【００１２】
外シール部材の逃げ用凹部とシャフト及び中間シール部材との間に形成される空隙に、シリコーン樹脂等の硬化性樹脂を充填しても良い。硬化性樹脂の充填は、例えば上記空気抜き穴を利用して行なうことができる。硬化性樹脂の充填により、中間シール部材のシール穴部とシャフトとの間、外シール部材のシール筒部とシャフトとの間のシール性をより一層向上させることができる。
【００１３】
内シール部材の凸球状外面と中間シール部材の凹球状内面との間に、両者の密着性および摺動性を強化する潤滑剤を塗布することができる。このようにすることで、シール性を高め、かつ、等速自在継手の屈曲抵抗を下げることができる。
【００１４】
内シール部材の凸球状外面に、中間シール部材との局部的な密着性を強化する円環状突起を付設することができる。このようにすることで、内シール部材と中間シール部材との間のシール性をより一層向上させることができる。
【００１５】
中間シール部材の凸球状外面と外シール部材の凹球状内面との間を接着剤で固定したり、あるいは、かみ合わせ手段を用いて相互にかみ合わせることにより、両者の密着性を強化しても良い。
【００１６】
【発明の実施の形態】
以下、本発明の実施形態を図１乃至図６を参照して説明する。尚、図１乃至図４は第１の実施形態を、図５は第２の実施形態を、図６は第３の実施形態を示し、全図を通じて同一、又は、相当部分には同一符号が付してある。
【００１７】
図１および図２は、固定型等速自在継手１の外側継手部材２とシャフト３に装着された第１の実施形態のダストシール４の断面を示し、図２は外側継手部材２とシャフト３が最大作動角をとった時の状態を示している。外側継手部材２は円筒状外周面２ａを有し、この外側継手部材２の中心線上に在るジョイント中心Ｐを中心にシャフト３が最大作動角の範囲内で角度変位する。シャフト３は、一端を固定型等速自在継手１の内側継手部材（図示省略）に連結される。例えば、シャフト３の一端に近い部分は小径に形成され（小径軸部３’）、角度変位時の外側継手部材２との干渉範囲を小さくとることで、最大作動角の増大が図られている。
【００１８】
ダストシール４は、外側継手部材２の円筒状外周面２ａに嵌着される内シール部材５と、内シール部材５およびシャフト３に嵌着される中間シール部材６と、中間シール部材６およびシャフト３に嵌着される外シール部材７の３つのシール部材で構成される。内シール部材５は外側継手部材２の円筒状外周面２ａに嵌着される略円筒状をなし、中間シール部材６と外シール部材７は同一球面中心を有する椀状をなす。内シール部材５と外シール部材７の少なくとも一方はプラスチック材、ゴム材、薄肉金属材料等の可撓性材料で成形され、中間シール部材６はゴム材、軟質樹脂材等のシール性に適した可撓性材料で形成される。この実施形態では、内シール部材５が金属材料、外シール部材７がプラスチック材、ゴム材、薄肉金属材料等の可撓性材料で成形されている。
【００１９】
図３に示すように、内シール部材５は、外側継手部材２の円筒状外周面２ａの全体に気密にシール性良く嵌着されて固定される円筒状内面５ａと、外側継手部材２に嵌着したときにジョイント中心Ｐを球面中心とする凸球状外面５ｂを有する略円筒体である。内シール部材５のシャフト３側の開口端部には、外側継手部材２の端面周縁部に当接する内突片５ｃが一体に形成される。
【００２０】
中間シール部材６は、内シール部材５の凸球状外面５ｂと同一中心（ジョイント中心Ｐ）の凹球状内面６ａと凸球状外面６ｂを有する椀状体で、一端の開口部６ｃから内シール部材５に嵌着される。開口部６ｃの外周には、ストッパー部６ｄが一体に突設される。中間シール部材６の他端の中央部にシール穴部６ｅが形成され、このシール穴部６ｅがシャフト３の小径軸部３’に嵌挿されて、小径軸部３’の外周をシールする。
【００２１】
外シール部材７は、中間シール部材６の凸球状外面６ｂと同一中心（ジョイント中心Ｐ）の凹球状内面７ａと凸球状外面７ｂを有する薄椀状体で、一端の開口部７ｃから中間シール部材６に嵌着される。外シール部材７の他端の中央部にシール筒部７ｄが形成され、このシール筒部７ｄにシャフト３に嵌挿される。シャフト３の小径軸部３’より他端側は大径軸部３”で、この大径軸部３”にシール筒部７ｄが嵌挿されて大径軸部３”をシールする。
【００２２】
外シール部材７のシール筒部７ｄは、シャフト３の大径軸部３”と同一径の均一円筒でもよいが、後述するダストシール組付性を改善する目的で、シール筒部７ｄの一部に逃げ用凹部８と空気抜き穴９を形成するのが良い。また、外シール部材７の外面形状は球面に限らないが、凹球状内面７ａと同一中心の凸球状外面７ｂにして外シール部材７の全体を略球椀状に薄肉化することが、ダストシール４の全体を小径小形化する上で望ましい。
【００２３】
以上の３つのシール部材５、６、７の相互の組付けは、等速自在継手１に組付ける前に、次の要領で行われる。
【００２４】
先ず、図３に示す外シール部材７に中間シール部材６を嵌着する。この場合、中間シール部材６の凸球状外面６ｂの直径Ｄ３が外シール部材７の円形開口部７ｃの内径Ｄ４より少し大きく設定されて、外シール部材７内に中間シール部材６はその可撓性により少し縮径されて圧入嵌挿される。外シール部材７に中間シール部材６が嵌挿されると、中間シール部材６のストッパー部６ｄに外シール部材７の開口部７ｃが当接して、両シール部材６、７が同軸に密着して一体化される。
【００２５】
次に、外シール部材７と中間シール部材６の組付け後に内シール部材５を圧入嵌着する。この場合、内シール部材５の凸球状外面５ｂの直径Ｄ１が中間シール部材６の開口部６ｃの内径Ｄ２より少し大きく設定されている。そこで、外シール部材７を可撓性の有るプラスチック材、ゴム材、薄肉金属材料等で形成し、内シール部材５を圧入するときに外シール部材７が弾性変形できるようにする。あるいは、内シール部材５を可撓性の有るプラスチック材、ゴム材、薄肉金属材料等で形成し、内シール部材５を圧入する時に、それが弾性変形できるようにしても良い。もちろん、内シール部材５と外シール部材７の双方を可撓性材料で形成し、双方が弾性変形できるようにしても良い。このようにすれば、３つのシール部材５、６、７の組付けが簡易に行え、また、組付後の弾性復元力で３つのシール部材５、６、７が安定した密着性をもった状態で、１つのダストシール４が組立られる。
【００２６】
ダストシール４は、図４に示すように、シャフト３から外側継手部材２へと嵌挿される。ダストシール４の中間シール部材６のシール穴部６ｅがシャフト３の大径軸部３”から小径軸部３’に嵌挿され、外シール部材７のシール筒部７ｄが大径軸部３”に嵌挿され、内シール部材５が外側継手部材２に嵌挿されて、ダストシール４の取付けが完了する。この取付けの場合、中間シール部材６のシール穴部６ｅは、シャフト３の大径軸部３”に押し広げられて弾性変形した状態で大径軸部３”に挿通され、大径軸部３”を離れたところで弾性復元して小径軸部３’に弾性的に嵌着される。
【００２７】
そこで、中間シール部材６のシール穴部６ｅがシャフト３の大径軸部３”で拡径され易いように、外シール部材７のシール筒部７ｄに逃げ用凹部８を形成して、シール穴部６ｅが大径軸部３”で拡径されたときの弾性変形部位を逃がすようにする。また、ダストシール４をシャフト３に挿通するときに中間シール部材６のシール穴部６ｅと外シール部材７のシール筒部７ｄの逃げ用凹部８とシャフト３の間に密閉空隙ｇが形成されてシール穴部６ｅの上記弾性変形を難しくし、ダストシール４のシャフト３への挿通を難しくすることがあるので、これを回避するためにシール筒部７ｄに空隙ｇの空気を抜く空気抜き穴９を形成する。このようにシール筒部７ｄに凹部８と空気抜き穴９を形成すれば、ダストシール４のシャフト３への挿通が容易になり、挿通後のダストシール４とシャフト３のシール性が強固で安定したものとなる。
【００２８】
以上のように等速自在継手１に装着されたダストシール４は、シャフト３と外側継手部材２とが作動角をとって回転する際、中間シール部材６の凹球状内面６ａが内シール部材５の凸球状外面５ｂに常時密着して円滑に摺動し、一方、中間シール部材６のシール穴部６ｅと外シール部材７のシール筒部７ｄがシャフト３の外周面に常時密着して、継手内部をシールするので、継手内へのダスト侵入と継手外へのグリース漏洩が防止される。特に、中間シール部材６は、内外両シール部材５、７の間のシール性を確保すると同時に、シャフト３との密着性を外シール部材７とで２段階的に行って、ダストシール４全体のシール性を安定したものにする上で有効である。
【００２９】
図１のダストシール４の外側継手部材２及びシャフト３との間のシール性をより安定した良好なものにするため、外側継手部材２に内シール部材５を接着剤等で固定してもよい。また、ダストシール４とシャフト３との間のシール性を確実にするため、図５の第２の実施形態のように、或いは、図６の第２の実施形態のようにしてもよい。
【００３０】
図５に示す第２の実施形態のダストシール４は、中間シール部材６のシール穴部６ｅを円筒状に形成して、このシール穴部６ｅの円筒部外周にシール補強手段１０を追加形成したものである。このシール補強手段１０は、シール穴部６ｅをシャフト３の小径軸部３’に弾圧的に締付ける別体のスプリング、或いは、シール穴部６ｅと一体の増肉部が有効である。このようなシール補強手段１０は、シール穴部６ｅを小径軸部３’に強く密着させ、その密着力を保持して中間シール部材６とシャフト３との間のシール性を高いものにする。
【００３１】
図６に示す第３の実施形態のダストシール４は、外シール部材７のシール筒部７ｄと中間シール部材６のシール穴部６ｅ及びシャフト３との間の空隙ｇにシリコーン樹脂などの硬化性樹脂１１を充填したものである。この硬化性樹脂１１の空隙ｇへの充填は、外シール部材７のシール筒部７ｄに形成された空気抜き穴９から行うことができる。空隙ｇに硬化性樹脂１１を充填させることで、外シール部材７および中間シール部材６とシャフト３との間のシール性がより一層向上する。
【００３２】
図７に示す第４の実施形態のダストシール４は、内シール部材５の凸球状外面に円環状突起５ｄを付設したものである。円環状突起５ｄを付設することにより、中間シール部材６の凹球状内面６ａとの局部的な密着性を高め、中間シール部材６と内シール部材５との間のシール性をより一層向上させることができる。尚、このような円環状突起５ｄはＯリング等によって代用しても良い。
【００３３】
図８に示す第５の実施形態のダストシール４は、中間シール部材６の凸球状外面６ｂに円環状突起６ｆを設け、外シール部材７の凹球状内面７ａに円環状溝７ｇを設けたものである。円環状突起６ｆと円環状溝７ｇとが相互にかみ合うことにより、中間シール部材６と外シール部材７との間のシール性が向上し、また両者のずれが防止される。中間シール部材６の凸球状外面６ｂは、外シール部材７の凹球状内面７ａに接着剤で固定しても良い。
【００３４】
また、内シール部材５と中間シール部材６との間に潤滑剤を塗布することにより、シール性、摺動性が向上する。また、内シール部材５の凸球面状外面に円環状突起を付設することにより、内シール部材５と中間シール部材６との間のシール性が向上する。また、中間シール部材６と外シール部材７とを接着剤で相互に固定し、あるいは、かみ合わせ手段により相互にかみ合わせることにより、密着性を向上させることができる。
【００３５】
【発明の効果】
本発明によれば、内シール部材、中間シール部材、及び外シール部材の３つのシール部材を組付けてダストシールを構成したので、ダストシール自体の構造簡素化、原価低減化が可能となり、かつ、等速自在継手へのダストシール組付工数の低減化が可能となる。また、可撓性の中間シール部材が内外両シール部材間のシール性とシャフトとの間のシール性を確保して、高シール構造のダストシールを実現する。
【００３６】
また、内シール部材と外シール部材の少なくとも一方を可撓性材料で形成することで、その一方あるいは両方の弾性変形を利用して、ダストシールの各部材の組付け、ダストシールの等速自在継手への組み付けを容易に行うことができる。さらに、外シール部材のシール筒部に、逃げ用凹部を形成し、また、空気抜き穴を形成することにより、ダストシールの等速自在継手への組み付けをより一層容易に行うことができる。
【００３７】
また、中間シール部材のシール穴部にこのシール穴部とシャフトとの密着性を強化するシール補強手段を付設することにより、中間シール部材とシャフトとの間のシール性が向上する。
【００３８】
また、外シール部材のシール筒部とシャフト及び中間シール部材との間に形成される空隙に硬化性樹脂を充填することにより、外シール部材および中間シール部材とシャフトとの間のシール性がより一層向上する。
【００３９】
また、内シール部材の凸球状外面と中間シール部材の凹球状内面との間に、両者の密着性および摺動性を強化する潤滑剤を塗布することにより、シール性を高め、かつ、等速自在継手の屈曲抵抗を下げることができる。
【００４０】
また、内シール部材の凸球状外面に、中間シール部材との局部的な密着性を強化する円環状突起を付設することにより、内シール部材と中間シール部材との間のシール性をより一層向上させることができる。
【００４１】
また、中間シール部材の凸球状外面と外シール部材の凹球状内面との間を接着剤で固定したり、あるいは、かみ合わせ手段を用いて相互にかみ合わせることにより、両者の密着性が向上する。
【図面の簡単な説明】
【図１】本発明の第１の実施形態を示す固定型等速自在継手に設置されたダストシールの断面図。
【図２】図１等速自在継手のシャフトを最大作動角で回転させたときの断面図。
【図３】図１ダストシールだけの分解断面図。
【図４】図１ダストシールを等速自在継手に組付けるときの断面図。
【図５】本発明の第２の実施形態を示すダストシールの部分断面図。
【図６】本発明の第３の実施形態を示すダストシールの部分断面図。
【図７】本発明の第４の実施形態を示すダストシールの部分断面図。
【図８】本発明の第５の実施形態を示すダストシールの部分断面図。
【符号の説明】
１等速自在継手
２外側継手部材
２ａ円筒状外周面
３シャフト
４ダストシール
５内シール部材
５ａ円筒状内面
５ｂ凸球状外面
５ｄ突起
６中間シール部材
６ａ凹球状内面
６ｂ凸球状外面
６ｅシール穴部
６ｆ円環状突起
７外シール部材
７ａ凹球状内面
７ｄシール筒部
７ｇ円環状溝
８逃げ用凹部
９空気抜き穴
１０シール補強手段
ｇ空隙[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dust seal that covers a constant velocity universal joint used in automobiles and various industrial machines to prevent dust from entering the joint and prevent leakage of grease and the like in the joint.
[0002]
[Prior art]
A bellows-shaped boot mounted for the purpose of preventing leakage of internal grease and preventing intrusion of external dust in a fixed type constant velocity universal joint that allows angular displacement between two shafts increases the operating angle of the shaft relative to the outer joint member. The bellows may interfere with each other, leading to a decrease in durability. Therefore, in a fixed type constant velocity universal joint used at a large operating angle, a spherical structure dust seal that wraps the outer joint member tends to be used instead of the bellows type boot.
[0003]
As disclosed in Japanese Patent Application Laid-Open No. 2-278016, which is a prior application of the present applicant, such a dust seal is fitted at both ends to the outer periphery of the outer joint member of the fixed type constant velocity universal joint and the outer periphery of the shaft. The basic structure is a bowl-shaped sphere. This bowl-shaped sphere has a single-layer or multi-layer structure, and a cylindrical portion formed in the center thereof is fixed to the shaft by band fastening or the like, and an opening portion of a spherical inner surface extending from the cylindrical portion in a bowl shape is an outer joint. The outer periphery of the member is slidably fitted. Also, between the sphere and the outer joint member, a dust seal part that prevents dust from entering the sphere from the outer periphery of the outer joint member, a grease seal part that prevents leakage of grease from the sphere to the outer periphery of the outer joint member, etc. A separate part is installed to keep the sealing part in good condition. Further, various attachment parts for attaching the sphere and various seal parts to the outer joint member and the shaft are used, and a dust seal excellent in durability and a sealing function is constructed and put into practical use.
[0004]
[Problems to be solved by the invention]
The above dust seal has excellent durability and sealability to prevent dust intrusion into the joint and leakage of grease to the outside of the joint, and there is little possibility of wear even if the operating angle of the shaft is large with respect to the outer joint member. Therefore, a fixed type constant velocity universal joint used at a large operating angle has been put into practical use as a highly reliable product. However, in order to achieve high sealing performance and high durability, the number of parts increases, making it difficult to reduce the cost of the dust seal itself, and the structure becomes complicated and the number of assembly steps to the constant velocity universal joint increases. This makes it difficult to reduce the manufacturing cost of the constant velocity universal joint.
[0005]
An object of the present invention is to provide a dust seal for a constant velocity universal joint that reduces the number of parts, facilitates cost reduction, and improves the assemblage to the constant velocity universal joint.
[0006]
[Means for Solving the Problems]
The technical means of the present invention for achieving the above object includes a cylindrical inner surface fitted on a cylindrical outer peripheral surface of an outer joint member of a constant velocity universal joint, and a convex spherical outer surface centering on a joint center of the constant velocity universal joint. An inner seal member having a spherical surface having the same center as the convex spherical outer surface of the inner seal member, and a concave spherical inner surface fitted to be slidable on the convex spherical outer surface of the inner seal member, and having the same center as the concave spherical inner surface A flexible intermediate seal member having a convex spherical outer surface and a seal hole portion that is fitted and sealed in the shaft of the constant velocity universal joint at the center, and is integrally fitted on the convex spherical outer surface of the intermediate seal member. Containing a concave spherical inner surface and a bowl-shaped outer seal member having a seal cylinder portion fitted to the shaft so as to cover the seal hole portion of the intermediate seal member fitted to the shaft of the constant velocity universal joint at the center portion It is to have done.
[0007]
The intermediate sealing material is a bowl-shaped material made of a flexible material suitable for sealing properties such as rubber and soft resin, and is attached to the shaft of the constant velocity universal joint integrally with the outer sealing member. When the shaft is angularly displaced about the joint center with respect to the outer joint member, the intermediate seal member is angularly displaced along with the shaft and the outer seal member, and always slides on the convex spherical outer surface of the inner seal member fixed to the outer joint member. Touch and seal the inside of the joint.
[0008]
When at least one of the inner seal member and the outer seal member is formed of a flexible material, the inner seal member is fitted when the outer seal member fitted to the intermediate seal member is fitted to the inner seal member via the intermediate seal member. The inner and outer seal members can be assembled by elastically deforming one or both of the member and the outer seal member. Therefore, the assembling property of the dust seal itself and the assembling property of the dust seal to the constant velocity universal joint are good. As the flexible material here, for example, plastic, rubber, or thin metal can be used.
[0009]
It is preferable to form a relief recess in the elastically deformed portion of the seal hole when the seal hole of the intermediate seal member is fitted into the shaft of the constant velocity universal joint in the seal cylinder of the outer seal member. In this way, it becomes easy to elastically deform and elastically insert the seal hole portion of the intermediate seal member into the shaft of the constant velocity universal joint, and the seal hole portion of the intermediate seal member is elastically inserted into the shaft. It becomes easy to fit in with high sealing performance.
[0010]
Moreover, it is good to form the air vent hole which escapes the air of the space | gap formed between the recessed part for escape, a shaft, and an intermediate | middle seal member in the seal cylinder part of an outer seal member. By doing in this way, the operation | work at the time of inserting and inserting the seal hole part of an intermediate seal member in the shaft of a constant velocity universal joint becomes easy.
[0011]
In order to improve the adhesion between the seal hole portion of the intermediate seal member and the shaft of the constant velocity universal joint, a seal reinforcing means may be attached to the seal hole portion. As the seal reinforcing means, a means for forming the seal hole portion partially thick or a spring means for elastically tightening the seal hole portion from the outer diameter side can be employed.
[0012]
A gap formed between the escape recess of the outer seal member and the shaft and the intermediate seal member may be filled with a curable resin such as a silicone resin. The filling of the curable resin can be performed using, for example, the air vent hole. By filling the curable resin, it is possible to further improve the sealability between the seal hole portion of the intermediate seal member and the shaft and between the seal tube portion of the outer seal member and the shaft.
[0013]
Between the convex spherical outer surface of the inner seal member and the concave spherical inner surface of the intermediate seal member, it is possible to apply a lubricant that enhances the adhesion and slidability of both. By doing in this way, a sealing performance can be improved and the bending resistance of a constant velocity universal joint can be reduced.
[0014]
An annular projection that reinforces local adhesion with the intermediate seal member can be attached to the convex spherical outer surface of the inner seal member. By doing in this way, the sealing performance between an inner seal member and an intermediate seal member can be improved further.
[0015]
The adhesiveness between the convex spherical outer surface of the intermediate seal member and the concave spherical inner surface of the outer seal member may be enhanced by fixing with an adhesive, or by engaging with each other using a meshing means. .
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 6. 1 to 4 show the first embodiment, FIG. 5 shows the second embodiment, and FIG. 6 shows the third embodiment. The same reference numerals are used for the same or corresponding parts throughout the drawings. It is attached.
[0017]
1 and 2 show a cross section of the dust seal 4 of the first embodiment mounted on the outer joint member 2 and the shaft 3 of the fixed type constant velocity universal joint 1, and FIG. 2 shows the outer joint member 2 and the shaft 3. The state when the maximum operating angle is taken is shown. The outer joint member 2 has a cylindrical outer peripheral surface 2 a, and the shaft 3 is angularly displaced within the range of the maximum operating angle around the joint center P on the center line of the outer joint member 2. One end of the shaft 3 is connected to an inner joint member (not shown) of the fixed type constant velocity universal joint 1. For example, the portion close to one end of the shaft 3 is formed with a small diameter (small diameter shaft portion 3 ′), and the maximum operating angle is increased by reducing the interference range with the outer joint member 2 at the time of angular displacement. .
[0018]
The dust seal 4 includes an inner seal member 5 fitted to the cylindrical outer peripheral surface 2 a of the outer joint member 2, an intermediate seal member 6 fitted to the inner seal member 5 and the shaft 3, and the intermediate seal member 6 and the shaft 3. It is comprised by three seal members of the outer seal member 7 fitted by. The inner seal member 5 has a substantially cylindrical shape fitted to the cylindrical outer peripheral surface 2a of the outer joint member 2, and the intermediate seal member 6 and the outer seal member 7 have a bowl shape having the same spherical center. At least one of the inner seal member 5 and the outer seal member 7 is formed of a flexible material such as a plastic material, a rubber material, or a thin metal material, and the intermediate seal member 6 is suitable for sealing properties such as a rubber material or a soft resin material. Made of flexible material. In this embodiment, the inner seal member 5 is molded from a metal material, and the outer seal member 7 is molded from a flexible material such as a plastic material, a rubber material, or a thin metal material.
[0019]
As shown in FIG. 3, the inner seal member 5 is fitted to the outer joint member 2 and the cylindrical inner surface 5 a that is airtightly fitted and fixed to the entire cylindrical outer peripheral surface 2 a of the outer joint member 2. It is a substantially cylindrical body having a convex spherical outer surface 5b with the joint center P as the spherical center when worn. An inner projecting piece 5 c that comes into contact with the peripheral edge portion of the outer joint member 2 is integrally formed at the opening end portion of the inner seal member 5 on the shaft 3 side.
[0020]
The intermediate seal member 6 is a bowl-shaped body having a concave spherical inner surface 6a and a convex spherical outer surface 6b having the same center (joint center P) as the convex spherical outer surface 5b of the inner seal member 5, and the inner seal member 5 from the opening 6c at one end. To be fitted. A stopper portion 6d is integrally projected on the outer periphery of the opening 6c. A seal hole 6e is formed at the center of the other end of the intermediate seal member 6, and this seal hole 6e is fitted into the small diameter shaft 3 'of the shaft 3 to seal the outer periphery of the small diameter shaft 3'.
[0021]
The outer seal member 7 is a thin bowl-shaped body having a concave spherical inner surface 7a and a convex spherical outer surface 7b having the same center (joint center P) as the convex spherical outer surface 6b of the intermediate seal member 6, and the intermediate seal member from the opening 7c at one end. 6. A seal cylinder portion 7d is formed at the center of the other end of the outer seal member 7, and the shaft 3 is fitted into the seal cylinder portion 7d. The other end side of the small-diameter shaft portion 3 ′ of the shaft 3 is a large-diameter shaft portion 3 ″, and a seal cylinder portion 7d is fitted into the large-diameter shaft portion 3 ″ to seal the large-diameter shaft portion 3 ″.
[0022]
The seal cylinder portion 7d of the outer seal member 7 may be a uniform cylinder having the same diameter as the large-diameter shaft portion 3 ″ of the shaft 3. However, for the purpose of improving the dust seal assemblage described later, It is preferable to form a recess 8 for escape and an air vent hole 9. The outer surface shape of the outer seal member 7 is not limited to a spherical surface, but a convex spherical outer surface 7b having the same center as the concave spherical inner surface 7a is used. It is desirable to reduce the thickness of the entire dust seal 4 to a small diameter and a small size.
[0023]
The above three seal members 5, 6, 7 are assembled in the following manner before being assembled to the constant velocity universal joint 1.
[0024]
First, the intermediate seal member 6 is fitted to the outer seal member 7 shown in FIG. In this case, the diameter D3 of the convex spherical outer surface 6b of the intermediate seal member 6 is set to be slightly larger than the inner diameter D4 of the circular opening 7c of the outer seal member 7, and the intermediate seal member 6 is flexible in the outer seal member 7. Is slightly reduced in diameter and press-fitted and inserted. When the intermediate seal member 6 is inserted into the outer seal member 7, the opening 7c of the outer seal member 7 comes into contact with the stopper portion 6d of the intermediate seal member 6, and both the seal members 6 and 7 are coaxially in close contact with each other. It becomes.
[0025]
Next, after the outer seal member 7 and the intermediate seal member 6 are assembled, the inner seal member 5 is press-fit. In this case, the diameter D 1 of the convex spherical outer surface 5 b of the inner seal member 5 is set to be slightly larger than the inner diameter D 2 of the opening 6 c of the intermediate seal member 6. Therefore, the outer seal member 7 is formed of a flexible plastic material, rubber material, thin metal material or the like so that the outer seal member 7 can be elastically deformed when the inner seal member 5 is press-fitted. Alternatively, the inner seal member 5 may be formed of a flexible plastic material, rubber material, thin metal material, or the like so that when the inner seal member 5 is press-fitted, it can be elastically deformed. Of course, both the inner seal member 5 and the outer seal member 7 may be formed of a flexible material so that both can be elastically deformed. In this way, the three seal members 5, 6, 7 can be easily assembled, and the three seal members 5, 6, 7 have stable adhesion due to the elastic restoring force after the assembly. In the state, one dust seal 4 is assembled.
[0026]
As shown in FIG. 4, the dust seal 4 is fitted into the outer joint member 2 from the shaft 3. The seal hole portion 6e of the intermediate seal member 6 of the dust seal 4 is fitted into the small diameter shaft portion 3 ′ from the large diameter shaft portion 3 ″ of the shaft 3, and the seal cylinder portion 7d of the outer seal member 7 is changed to the large diameter shaft portion 3 ″. The inner seal member 5 is inserted into the outer joint member 2 and the attachment of the dust seal 4 is completed. In the case of this attachment, the seal hole portion 6e of the intermediate seal member 6 is inserted into the large diameter shaft portion 3 ″ in a state of being elastically deformed by being pushed over the large diameter shaft portion 3 ″ of the shaft 3, and the large diameter shaft portion 3 It is elastically restored to the small diameter shaft portion 3 ′ at a distance away from “”.
[0027]
Therefore, a relief recess 8 is formed in the seal cylinder portion 7d of the outer seal member 7 so that the seal hole portion 6e of the intermediate seal member 6 is easily expanded in diameter by the large diameter shaft portion 3 ″ of the shaft 3. The elastic deformation part when the part 6e is expanded by the large diameter shaft part 3 ″ is allowed to escape. Further, when the dust seal 4 is inserted through the shaft 3, a seal gap g is formed between the seal hole 6 e of the intermediate seal member 6 and the escape recess 8 of the seal cylinder portion 7 d of the outer seal member 7 and the shaft 3. Since the elastic deformation of the hole 6e is difficult and the insertion of the dust seal 4 into the shaft 3 may be difficult, an air vent hole 9 is formed in the seal cylinder portion 7d to remove air from the gap g in order to avoid this. . If the concave portion 8 and the air vent hole 9 are formed in the seal cylinder portion 7d in this way, the dust seal 4 can be easily inserted into the shaft 3, and the sealing performance of the dust seal 4 and the shaft 3 after insertion is strong and stable. Become.
[0028]
As described above, the dust seal 4 attached to the constant velocity universal joint 1 has the concave spherical inner surface 6a of the inner seal member 5 when the shaft 3 and the outer joint member 2 rotate at an operating angle. The convex spherical outer surface 5b is always in close contact and smoothly slides, while the seal hole portion 6e of the intermediate seal member 6 and the seal cylinder portion 7d of the outer seal member 7 are always in close contact with the outer peripheral surface of the shaft 3, Prevents dust from entering the joint and leakage of grease to the outside of the joint. In particular, the intermediate seal member 6 secures the sealability between the inner and outer seal members 5 and 7 and at the same time performs the adhesion with the shaft 3 in two steps with the outer seal member 7, thereby sealing the dust seal 4 as a whole. It is effective in stabilizing the sex.
[0029]
In order to make the sealing performance between the outer joint member 2 and the shaft 3 of the dust seal 4 of FIG. 1 more stable and good, the inner seal member 5 may be fixed to the outer joint member 2 with an adhesive or the like. Moreover, in order to ensure the sealing performance between the dust seal 4 and the shaft 3, the second embodiment shown in FIG. 5 or the second embodiment shown in FIG. 6 may be used.
[0030]
In the dust seal 4 of the second embodiment shown in FIG. 5, the seal hole 6e of the intermediate seal member 6 is formed in a cylindrical shape, and the seal reinforcing means 10 is additionally formed on the outer periphery of the cylindrical portion of the seal hole 6e. It is. The seal reinforcing means 10 is effective as a separate spring for elastically tightening the seal hole 6e to the small-diameter shaft 3 'of the shaft 3, or a thickened part integral with the seal hole 6e. Such a seal reinforcing means 10 brings the seal hole 6e into close contact with the small-diameter shaft portion 3 ′ and maintains the close contact force to improve the sealing performance between the intermediate seal member 6 and the shaft 3.
[0031]
The dust seal 4 of the third embodiment shown in FIG. 6 has a curable resin such as a silicone resin in the gap g between the seal cylinder portion 7d of the outer seal member 7, the seal hole portion 6e of the intermediate seal member 6, and the shaft 3. 11 is filled. Filling the gap g with the curable resin 11 can be performed from the air vent hole 9 formed in the seal tube portion 7 d of the outer seal member 7. By filling the gap g with the curable resin 11, the sealing performance between the outer seal member 7 and the intermediate seal member 6 and the shaft 3 is further improved.
[0032]
The dust seal 4 according to the fourth embodiment shown in FIG. 7 has an annular protrusion 5 d attached to the convex spherical outer surface of the inner seal member 5. By providing the annular protrusion 5d, local adhesion to the concave spherical inner surface 6a of the intermediate seal member 6 is enhanced, and the sealing performance between the intermediate seal member 6 and the inner seal member 5 is further improved. Can do. Such an annular projection 5d may be substituted by an O-ring or the like.
[0033]
The dust seal 4 of the fifth embodiment shown in FIG. 8 is provided with an annular protrusion 6f on the convex spherical outer surface 6b of the intermediate seal member 6 and an annular groove 7g on the concave spherical inner surface 7a of the outer seal member 7. is there. Since the annular projection 6f and the annular groove 7g are engaged with each other, the sealing performance between the intermediate seal member 6 and the outer seal member 7 is improved, and the shift between both is prevented. The convex spherical outer surface 6b of the intermediate seal member 6 may be fixed to the concave spherical inner surface 7a of the outer seal member 7 with an adhesive.
[0034]
Further, by applying a lubricant between the inner seal member 5 and the intermediate seal member 6, the sealing performance and the sliding performance are improved. Further, by providing an annular projection on the convex spherical outer surface of the inner seal member 5, the sealing performance between the inner seal member 5 and the intermediate seal member 6 is improved. Also, the intermediate seal member 6 and the outer seal member 7 can be fixed to each other with an adhesive, or can be improved by contact with each other by means of engagement.
[0035]
【The invention's effect】
According to the present invention, since the dust seal is configured by assembling the three seal members of the inner seal member, the intermediate seal member, and the outer seal member, the structure of the dust seal itself can be simplified, the cost can be reduced, and the like. It is possible to reduce the number of man-hours for attaching the dust seal to the quick universal joint. Further, the flexible intermediate seal member ensures the sealability between the inner and outer seal members and the sealability between the shafts, and realizes a dust seal with a high seal structure.
[0036]
Further, by forming at least one of the inner seal member and the outer seal member with a flexible material, the elastic deformation of one or both of them can be used to assemble each member of the dust seal, or to a constant velocity universal joint of the dust seal. Can be easily assembled. Furthermore, by forming a recess for escape in the seal cylinder portion of the outer seal member and forming an air vent hole, the dust seal can be more easily assembled to the constant velocity universal joint.
[0037]
Moreover, the sealing performance between the intermediate seal member and the shaft is improved by providing the seal hole portion of the intermediate seal member with a seal reinforcing means for enhancing the adhesion between the seal hole portion and the shaft.
[0038]
Further, by filling the gap formed between the seal cylinder portion of the outer seal member and the shaft and the intermediate seal member with a curable resin, the sealability between the outer seal member and the intermediate seal member and the shaft is further improved. Further improvement.
[0039]
Further, by applying a lubricant that enhances the adhesion and sliding property between the convex spherical outer surface of the inner seal member and the concave spherical inner surface of the intermediate seal member, the sealing performance is improved and the constant velocity is achieved. The bending resistance of the universal joint can be lowered.
[0040]
In addition, by providing an annular protrusion on the convex spherical outer surface of the inner seal member to enhance local adhesion with the intermediate seal member, the sealing performance between the inner seal member and the intermediate seal member is further improved. Can be made.
[0041]
Further, by fixing the convex spherical outer surface of the intermediate seal member and the concave spherical inner surface of the outer seal member with an adhesive, or by engaging each other using a meshing means, the adhesion between the two is improved.
[Brief description of the drawings]
FIG. 1 is a sectional view of a dust seal installed in a fixed type constant velocity universal joint according to a first embodiment of the present invention.
2 is a sectional view of the constant velocity universal joint when the shaft of the constant velocity universal joint is rotated at the maximum operating angle. FIG.
FIG. 3 is an exploded cross-sectional view of only the dust seal of FIG.
4 is a cross-sectional view when the dust seal is assembled to the constant velocity universal joint. FIG.
FIG. 5 is a partial cross-sectional view of a dust seal showing a second embodiment of the present invention.
FIG. 6 is a partial cross-sectional view of a dust seal showing a third embodiment of the present invention.
FIG. 7 is a partial cross-sectional view of a dust seal showing a fourth embodiment of the present invention.
FIG. 8 is a partial cross-sectional view of a dust seal showing a fifth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Constant velocity universal joint 2 Outer joint member 2a Cylindrical outer peripheral surface 3 Shaft 4 Dust seal 5 Inner seal member 5a Cylindrical inner surface 5b Convex spherical outer surface 5d Protrusion 6 Intermediate seal member 6a Concave spherical inner surface 6b Convex spherical outer surface 6e Seal hole 6f Circle Annular projection 7 Outer seal member 7a Concave spherical inner surface 7d Seal cylinder portion 7g Annular groove 8 Recessed recess 9 Air vent hole 10 Seal reinforcing means g Air gap

Claims

等速自在継手の外側継手部材の円筒状外周面に嵌着される円筒状内面、及び、等速自在継手のジョイント中心を球面中心とする凸球状外面を有する内シール部材と、
内シール部材の凸球状外面と同一中心の球面で内シール部材の凸球状外面に摺接可能に被嵌される凹球状内面、この凹球状内面と同一中心の凸球状外面、及び、中央部に等速自在継手のシャフトに嵌着されてシールするシール穴部を有する可撓性の中間シール部材と、
中間シール部材の凸球状外面に一体的に被嵌される凹球状内面、及び、中央部に等速自在継手のシャフトに嵌着された中間シール部材のシール穴部を被覆してシャフトに嵌着されるシール筒部を有する椀状の外シール部材と、
を具備したことを特徴とする等速自在継手用ダストシール。A cylindrical inner surface fitted to the cylindrical outer peripheral surface of the outer joint member of the constant velocity universal joint, and an inner seal member having a convex spherical outer surface with the joint center of the constant velocity universal joint as a spherical center;
A concave spherical inner surface that is slidably fitted to the convex spherical outer surface of the inner seal member with a spherical surface having the same center as the convex spherical outer surface of the inner seal member, a convex spherical outer surface that is the same center as the concave spherical inner surface, and a central portion A flexible intermediate seal member having a seal hole fitted and sealed to the shaft of the constant velocity universal joint;
The concave spherical inner surface that is integrally fitted to the convex spherical outer surface of the intermediate seal member, and the seal hole portion of the intermediate seal member that is fitted to the shaft of the constant velocity universal joint at the center are covered with the shaft. A bowl-shaped outer seal member having a sealed tube portion;
A dust seal for a constant velocity universal joint.

内シール部材と外シール部材の少なくとも一方が可撓性材料で形成されていることを特徴とする請求項１記載の等速自在継手用ダストシール。The dust seal for a constant velocity universal joint according to claim 1, wherein at least one of the inner seal member and the outer seal member is formed of a flexible material.

外シール部材のシール筒部に、等速自在継手のシャフトに中間シール部材のシール穴部を嵌挿する際のシール穴部の弾性変形部位の逃げ用凹部を形成したことを特徴とする請求項１又は２記載の等速自在継手用ダストシール。5. A relief recess for an elastically deformed portion of the seal hole portion when the seal hole portion of the intermediate seal member is fitted into the shaft of the constant velocity universal joint is formed in the seal cylinder portion of the outer seal member. A dust seal for a constant velocity universal joint according to 1 or 2.

外シール部材のシール筒部に、逃げ用凹部と等速自在継手のシャフト及び中間シール部材との間に形成される空隙の空気を逃がす空気抜き穴を形成したことを特徴とする請求項３記載の等速自在継手用ダストシール。The air cylinder according to claim 3, wherein an air vent hole is formed in the seal tube portion of the outer seal member for releasing air in a gap formed between the escape recess and the shaft of the constant velocity universal joint and the intermediate seal member. Dust seal for constant velocity universal joint.

中間シール部材のシール穴部に、このシール穴部と等速自在継手のシャフトとの密着性を強化するシール補強手段を付設したことを特徴とする請求項３又は４記載の等速自在継手用ダストシール。5. The constant velocity universal joint according to claim 3, wherein a seal reinforcing means for reinforcing adhesion between the seal hole portion and the shaft of the constant velocity universal joint is attached to the seal hole portion of the intermediate seal member. Dust seal.

外シール部材の逃げ用凹部と、等速自在継手のシャフト及び中間シール部材との間に形成される空隙に硬化性樹脂を充填したことを特徴とする請求項３、４又は５記載の等速自在継手用ダストシール。6. The constant velocity according to claim 3, 4 or 5, characterized in that a curable resin is filled in a gap formed between the escape recess of the outer seal member and the shaft and intermediate seal member of the constant velocity universal joint. Dust seal for universal joints.

内シール部材と中間シール部材との間に密着性および摺動性を強化する潤滑剤を塗布したことを特徴とする請求項３、４、５又は６記載の等速自在継手用ダストシール。7. The dust seal for a constant velocity universal joint according to claim 3, wherein a lubricant that enhances adhesion and slidability is applied between the inner seal member and the intermediate seal member.

内シール部材の凸球状外面に、中間シール部材との局部的な密着性を強化する円環状突起を付設したことを特徴とする請求項３、４、５、６又は７記載の等速自在継手用ダストシール。The constant velocity universal joint according to claim 3, 4, 5, 6, or 7, wherein an annular projection for reinforcing local adhesion with the intermediate seal member is attached to the convex spherical outer surface of the inner seal member. Dust seal.

中間シール部材の凸球状外面と外シール部材の凹球状内面との間に、中間シール部材と外シール部材との密着性を強化する接着剤、又はかみ合わせ手段を付設したことを特徴とする請求項３、４、５、６、７又は８記載の等速自在継手用ダストシール。The adhesive or meshing means for reinforcing the adhesion between the intermediate seal member and the outer seal member is provided between the convex spherical outer surface of the intermediate seal member and the concave spherical inner surface of the outer seal member. The dust seal for a constant velocity universal joint according to 3, 4, 5, 6, 7 or 8.