JP3728476B2

JP3728476B2 - Oil seal

Info

Publication number: JP3728476B2
Application number: JP15798396A
Authority: JP
Inventors: 豊若島
Original assignee: Koyo Seiko Co Ltd
Current assignee: Koyo Seiko Co Ltd
Priority date: 1996-06-19
Filing date: 1996-06-19
Publication date: 2005-12-21
Anticipated expiration: 2016-06-19
Also published as: JPH102423A

Description

【０００１】
【発明の属する技術分野】
本発明は、オイルシールに関する。ここでのオイルシールは、例えば、圧延機のワークロールネック用軸受などといった比較的大型のものに使用するのに適している。
【０００２】
【従来の技術】
一般的に、オイルシールは、周方向に連続する合成ゴムなどで形成されており、回転軸などの摺接相手に対する接触圧を適宜に設定することにより、所要のシール性能を管理するようになっている。
【０００３】
シール性能とは、外部空間に存在する水などが密封空間へ侵入するのを阻むことや、密封空間のグリースやオイルなどの潤滑油が過剰なときに過剰分を外部空間に排出することなどである。
【０００４】
【発明が解決しようとする課題】
ところで、圧延機のワークロールネック用軸受などといった比較的大型のオイルシールでは、シールリップが剛体化して可撓性が低下するために、回転軸の回転振れに対する追従性が悪くなる傾向となる。このように追従性が悪いということは、回転軸の回転振れに伴い、回転軸の外周面との間に隙間ができやすくなってしまい、この隙間から密封空間へ外部から水が容易に侵入することになる、という不具合が生ずる。
【０００５】
これとは別に、回転軸との摺接抵抗の軽減を目的として、オイルシールを、例えばテフロンなどのフッ素系樹脂で形成することがある。このようなフッ素系樹脂からなるオイルシールは、合成ゴムに比べてかなり硬質であるために、上述したような大型でなくとも、回転軸の回転振れに対する追従性が悪いことが指摘され、上記と同様の不具合が生ずる。
【０００６】
したがって、本発明は、オイルシールにおいて、簡易に製作できて、しかも安定なシール性能および回転軸の回転振れに対する良好な追従性を発揮できるようにすることを目的としている。
【０００７】
【課題を解決するための手段】
本発明の第１のオイルシールは、回転軸の外周面に対して斜めに当接させられるオイルシールであって、軸方向に重ね合わされる第１環状シート及び第２環状シート、並びに両環状シートを結合する結合部材とを備え、両環状シートには、それぞれ周方向所要間隔おきに径方向内向きに突出する舌片が設けられていて、舌片と該舌片に隣接する舌片との間には離間領域を有し、前記舌片の周方向他端側には前記環状シートの内周面のうち最も中心側でありかつ中心側へ突出した先鋭角部を備え、前記第１環状シートの舌片の付け根側には周方向他端側から周方向一端側に向かって所要長さの切り込みが設けられ、前記第１環状シールは密封空間側に配設され、前記第２環状シートは外部空間側に前記第１環状シートと同軸に配設され、前記第１環状シートの舌片の前記切り込みに前記第２環状シートの舌片を差し込むことで、前記第１環状シートの先鋭角部が前記第２環状シートの舌片の軸方向外部空間側にある。
また、本発明の第１のオイルシールにおいて、前記両環状シートの各舌片の周方向一端側の一端辺は、径方向外側から中心側に向かうにつれて、他端側に傾斜していることが好ましい。
本発明の第２のオイルシールは、回転軸の外周面に対して斜めに当接させられるオイルシールであって、軸方向に重ね合わされる第１環状シート及び第２環状シート、並びに両環状シートを結合する結合部材とを備え、両環状シートには、それぞれ周方向所要間隔おきに径方向内向きに突出す舌片が設けられていて、舌片と該舌片に隣接する舌片との間には離間領域を有し、前記舌片の周方向両端側には先鋭角部又は先鋭凸部を備え、前記先鋭角部又は先鋭凸部は前記各環状シートの内周面の径方向で最も内側に位置し、前記舌片の両端側の各先鋭角部の間又は各先鋭凸部の間は内径辺であり、前記第１環状シートは外部空間側に配設され、前記第２環状シートは密封空間側に配設され、前記第１環状シートの内径辺と前記第２環状シートの内径辺とが周方向に重ならないように第１環状シートと第２環状シートとを位相をずらして重ね合わせることにより両環状シートの隣り合う舌片間の離間領域に互いに相手となる環状シートの舌片が位置させられている。
本発明の第２のオイルシールにおいて、前記第２環状シートの各舌片の先鋭角部又は先鋭凸部より両端側は径方向外側から中心側に向かうにつれて、内径辺側に傾斜していてもよい。
本発明の第２のオイルシールにおいて、前記第１環状シートの各舌片の先鋭角部又は先鋭凸部より両端側は径方向外側から中心側に向かうにつれて、内径辺側に傾斜していてもよい。
【０００８】
なお、前述のオイルシールにおいて、結合部材は、各環状シートの外周側を軸方向両側から挟持する二つの環状板で構成することができる。両環状シートの各舌片において回転軸の回転方向上流側の端辺は、回転軸の回転方向に傾斜するのが好ましい。両環状シートの各舌片の内径辺において回転軸の回転方向下流側の角部は、径方向内向きに先鋭に突出するのが好ましい。一方の環状シートには、その舌片の付け根部分において回転軸の回転方向下流側から上流側へ向かう所要長さの切り込みを設けるのが好ましい。密封空間側の環状シートの各舌片において、周方向一端辺を回転軸の正回転方向に、また、周方向他端辺を回転軸の逆回転方向に、それぞれ傾斜するのが好ましい。外部空間側の環状シートの各舌片において、周方向一端辺を回転軸の正回転方向に、また、周方向他端辺を回転軸の逆回転方向に、それぞれ傾斜するのが好ましい。両環状シートの各舌片の内径辺は、周方向中央を谷とするような凹状に湾曲して、その曲率を各舌片の内接円径の曲率よりも大に設定するのが好ましい。
【０００９】
上記本発明では、要するに、環状シートの内周を周方向で連続したものにせずに、内周の円周数箇所に舌片を設けたものとし、この環状シートを二つ周方向に位相をずらして軸方向に重ね合わせたものとすることにより、柔軟性を持たせている。
【００１０】
また、本発明のオイルシールは、二つの環状シートの外周側を結合するだけであるから、製作上の取り扱いが容易であり、組み立て作業が簡易に行える。
【００１１】
さらに、本発明のオイルシールは、回転軸を正逆いずれか一方のみの回転方向に限定するときに、過剰な潤滑油の排出ならびに水の侵入阻止といったシール性能を良好に発揮できるようにした、一方向回転タイプとしたり、あるいは、回転軸の正逆いずれの回転方向としても、過剰な潤滑油の排出ならびに回転方向に水の侵入阻止といったシール性能を良好に発揮できるようにした、両方向回転タイプとしたりすることができる。つまり、舌片の周方向端部を軸方向で重ねることにより、隣り合う舌片の重ね合わせ部分に段差ができて回転軸との間に微小隙間ができるから、この微小隙間が潤滑油の排出通路となるのである。但し、この微小隙間は、潤滑油の排出後に潤滑油が存在して塞がれるので、水の侵入通路とならずに済む。
【００１２】
しかも、本発明では、舌片の周方向端辺を回転方向に傾斜させれば、潤滑油の排出をスムーズにすることができる。また、舌片の角部を先鋭にすれば、水が排出通路としての微小隙間へ向かわないように跳ね飛ばすことができる。
【００１３】
【発明の実施の形態】
以下、本発明の詳細を図１ないし図９に示す実施例に基づいて説明する。
【００１４】
図１ないし図５は本発明の実施例１にかかり、図１は、オイルシールの正面図、図２は、図１の（２）−（２）線断面矢視図、図３は、図２の（３）−（３）線断面矢視図、図４は、二つの環状シートの組み合わせ手順を示す説明図、図５は、回転軸に対するオイルシールの接触領域を外径側から見た図である。なお、図１では、オイルシールＡの内周を真っすぐにした状態で記載しているが、実際には図２のように内周が湾曲している。
【００１５】
図中、Ａはオイルシールの全体を示しており、Ｂは回転軸である。この実施例のオイルシールＡは、二つの環状シートを重ね合わせた構造として柔軟性を持たせた上で、回転軸Ｂを正逆いずれか一方向に回転する状況で安定なシール性能を発揮できるようにした、一方向回転タイプとしている。
【００１６】
具体的に、オイルシールＡは、軸方向に重ね合わされる二つの環状シート１，２と、これら環状シート１，２それぞれを重ね合わせた状態で保持する二つの環状芯金３，４とから構成されている。
【００１７】
環状シート１，２は、それぞれ周方向所要間隔おきに径方向内向きに突出する舌片１１，２１が設けられていて、ほぼ同じ形状になっているが、第１環状シート１の舌片１１の付け根側にのみ、回転軸Ｂの回転方向下流側から上流側へ向けて所要長さの切り込み１２が設けられている。舌片１１，２１は、平面視ほぼ扇形であって、周方向一端辺（図の左側）１３，２３が回転軸Ｂの一方回転方向（時計方向）に傾斜されているが、周方向他端辺（図の右側）１４，２４は放射方向に沿っていて傾斜されていない。また、舌片１１，２１の内径辺１５，２５において周方向他端側（図の右側）の角１６，２６は、先鋭となるように突出されているが、周方向一端側（図の左側）の角１７，２７はテーパ状に後退されている。なお、これら環状シート１，２は、テフロンなどのフッ素系樹脂あるいは合成ゴムなどで形成することができる。
【００１８】
環状芯金３，４は、上半分の断面が逆さＬ字形に形成されており、軸方向に沿う円筒部３１，４１と、径方向内向きの環状板部３２，４２とからなる。この環状芯金３，４の環状板部３２，４２間に、軸方向で重ねた環状シート１，２の外周部が挟持されるようになっている。この両環状板部３２，４２の円周数箇所には、その間に挟持する環状シート１，２を保持するとともに二つの環状芯金３，４を一体化するためのリベット５が軸方向に貫通する状態で取り付けられている。なお、第２環状芯金４と第１環状シート１との間には、パッキン６が介在されている。
【００１９】
そして、環状芯金３，４に環状シート１，２を取り付けた状態では、環状シート１，２の舌片１１，２１は、回転軸Ｂの外周面に対して斜めから当接するような形状に湾曲させられている。
【００２０】
このようなオイルシールＡの組み立て方法を説明する。つまり、図４に示すように、第１環状シート１の上に第２環状シート２を載せてから、第２環状シート２を第１環状シート１に対して周方向一方へ所要角度だけ回すようにして、第１環状シート１の舌片１１の切り込み１２に第２環状シート２の舌片２１を差し込む。これにより、第１環状シート１の隣り合う舌片１１間の離間領域に第２環状シート２の舌片２１を位置させる。そして、第１環状芯金３を作業台上に、その環状板部３２の外面を下向きにした姿勢で置き、この第１環状芯金３の環状板部３２の内面に対して、前述のように組み合わせた第１，第２環状シート１，２を載せる。こうしてから、第１環状芯金３の円筒部３１に対して第２環状芯金４の円筒部４１を圧入嵌合することにより、両環状芯金３，４の環状板部３２，４２で環状シート１，２の外周側を挟持させる。この状態で、リベット５を順次取り付ける。
【００２１】
このように、実施例１のオイルシールＡは、打ち抜き加工された環状シート１，２を環状芯金３，４に挟持させて、リベット５で止めるだけで製作できるから、作業が簡易で自動化が容易となるなど、製作コストの無駄な上昇を可及的に抑制することができる。
【００２２】
次に、上記オイルシールＡの動作を説明する。なお、回転軸Ｂの回転方向は、図３の矢印で示すように、時計方向のみに限定される。オイルシールＡは、回転軸Ｂの外周面に対して第１，第２環状シート１，２の舌片１１，２１はその片面における長手方向ほぼ半分領域が接触することになる。この状態では、第１環状シート１の舌片１１と第２環状シート２の舌片２１との重合に伴い形成される段差が原因で、図３に示すように、回転軸Ｂとの間に微小隙間が形成されることになる。
【００２３】
このようなオイルシールＡでは、密封空間に存在するグリースまたはオイルなどの潤滑油が過剰であると、図５の実線矢印で示すように、環状シート１，２の舌片１１，２１の一端辺１３，２３により回転方向下流へ導かれて、前述の微小隙間から外部へ排出されることになる。この微小隙間は、過剰な潤滑油を排出した後、潤滑油が残存するために塞がれることになる。
【００２４】
また、オイルシールＡの外部空間側に水がかかったとき、水は、第１、第２環状シート１，２の舌片１１，２１の内径辺１５，２５および先鋭角部１６，２６によって、図５の一点鎖線矢印のように、上記潤滑油排出通路となる微小隙間から遠ざけるように跳ね飛ばされることになり、密封空間側へ水が侵入するのを阻む。
【００２５】
ところで、回転軸Ｂの回転振れが起こった場合、オイルシールＡの各々独立する舌片１１，２１が必要に応じて比較的柔軟に撓んで回転軸Ｂの振れに追従するため、回転軸Ｂとの間に隙間が形成されずに済む。したがって、このような回転軸Ｂの回転振れが起こったときでも外部空間から水が密封空間へ侵入するのを阻むことができる。
【００２６】
図６ないし図９は本発明の実施例２にかかり、図６は、図１に対応するオイルシールの正面図、図７は、図３に対応する図、図８は、図４に対応する図、図９は、図５に対応する図である。
【００２７】
この実施例２では、回転軸Ｂを正逆いずれの方向に回転する場合でも安定なシール性能を発揮できるようにした、両方向回転タイプにしている。そのために、環状シート１，２の舌片１１，２１の形状を上記実施例１のものと異ならせている。
【００２８】
具体的に、第１，第２環状シート１，２は、舌片１１，２１の形状が若干相違するが、いずれも舌片１１，２１が、周方向前後で対称な形になっている。
【００２９】
第１環状シート１の舌片１１は、平面視ほぼ扇形であって、周方向の一端辺１３が回転軸Ｂの正回転方向（例えば時計方向）に、また、周方向の他端辺１４が回転軸Ｂの逆回転方向（例えば反時計方向）にそれぞれ所要角度傾斜されている。さらに、舌片１１の内径辺１５は、周方向中央を谷とするような凹状に湾曲されていて、その曲率が内接円径の曲率よりも大に設定されており、それによって内径辺１５の周方向両端の角１６，１７が先鋭な形状に形成されている。
【００３０】
一方、第２環状シート２の舌片２１は、第１環状シート１の舌片１１の周方向両端を延ばした形状になっている。この舌片２１の周方向一端辺２３は回転軸Ｂの正回転方向（例えば時計方向）に、また、周方向の他端辺２４は回転軸Ｂの逆回転方向（例えば反時計方向）にそれぞれ所要角度傾斜されている。また、舌片２１の内径辺２５は、二つの先鋭凸部２６，２７を形成するような波打ち形状に形成されている。この内径辺２５において二つの先鋭凸部２６，２７の間の領域の曲率は、内接円径の曲率よりも大に設定されている。
【００３１】
このようなオイルシールＡの組み立て方法を説明する。つまり、第１環状芯金３を作業台上に、その環状板部３２の外面を下向きにした姿勢で置き、この第１環状芯金３の環状板部３２の内面に対して、まず、第１環状シート１を載せて、その後、第１環状シート１に対して第２環状シート２を位相をずらして重ね合わせることにより、第１環状シート１の隣り合う舌片１１間の離間領域に第２環状シート２の舌片２１を位置させる。このとき、第１環状シート１の舌片１１の両端に第２環状シート２の舌片２１の両端を重ねる。こうしてから、第１環状芯金３の円筒部３１に対して第２環状芯金４の円筒部４１を圧入嵌合することにより、両環状芯金３，４の環状板部３２，４２で環状シート１，２の外周側を挟持させる。この状態で、リベット５を順次取り付ける。
【００３２】
この場合、上記実施例１のように第１環状シート１と第２環状シート２とを一体化する作業が不要であるから、より簡単に製作できるようになる。
【００３３】
次に、上記オイルシールＡの動作は、実施例１と基本的に同じであるが、回転軸Ｂの回転方向が正逆どちらであっても、過剰潤滑油の排出ならびに水侵入防止といったシール性能を良好に発揮するようになっている。なお、過剰な潤滑油の流れは、回転軸Ｂの回転方向が時計方向の場合だと、図９の実線矢印で示すように、また、回転軸Ｂの回転方向が反時計方向の場合だと、図９の破線矢印で示すようになる。水の流れは、回転軸Ｂの回転方向が時計方向の場合だと、図９の一点鎖線矢印で示すように、また、回転軸Ｂの回転方向が反時計方向の場合だと、図９の二点鎖線矢印で示すようになる。
【００３４】
なお、本発明は上記実施例のみに限定されるものではなく、種々な応用や変形が考えられる。
【００３５】
（１）環状シート１，２の舌片１１，２１の数は、例えば回転軸Ｂの外径寸法などに応じて任意に設定すればよい。
【００３６】
（２）二つの環状芯金３，４を用いているが、一方のみの環状芯金を用いるようにしてもよいし、また、環状芯金を用いずにリベット５のみで環状シート１，２を結合するようにしてもよい。さらに、二つの環状芯金３，４を圧入のみで比較的強固に結合すればリベット５を用いなくてもよい。
【００３７】
（３）上記実施例１において、第１環状シート１に切り込み１２を設けないようにしてもよい。
【００３８】
（４）上記実施例２では、二つの環状シート１，２を若干相違する形状にしているが、二つの環状シート１，２の形状を全く同じに設定してもよい。この場合だと、環状シート１，２が一種類で事足りるから、製造コストの低減に貢献できるようになる。
【００３９】
【発明の効果】
本発明では、過剰潤滑油の排出ならびに水侵入阻止といったシール性能を安定に発揮する構造とするとともに、柔軟性を持たせて回転軸の回転振れに対する追従性を高める構造としながら、製作を簡易にして製品価格の低減を図るようにしている。つまり、本発明のオイルシールは、比較的大きな外径に設定した場合でも、回転軸との摺接抵抗を軽減する硬質なフッ素系樹脂を素材とした場合でも、好適なシール性能を発揮できるようになる。特に本発明では、二つの環状シートを重ね合わせるだけで製作できるようにしているから、製作が容易で自動化が可能であるなど、製作コストが従来のワンピース構造のものに比べて著しく増加するのを回避できる。
【図面の簡単な説明】
【図１】本発明の実施例１のオイルシールの正面図
【図２】図１の（２）−（２）線断面矢視図
【図３】図２の（３）−（３）線断面矢視図
【図４】実施例１のオイルシールの二つの環状シートの組み合わせ手順を示す説明図
【図５】実施例１のオイルシールの回転軸に対する接触領域を外径側から見た図
【図６】本発明の実施例２のオイルシールの正面図
【図７】実施例２で、図３に対応する図
【図８】実施例２で、図４に対応する図
【図９】実施例２で、図５に対応する図
【符号の説明】
Ａオイルシール
Ｂ回転軸
１第１環状シート
１１第１環状シートの舌片
１２第１環状シートの切り込み
１３舌片の一端辺
１４舌片の他端辺
１５舌片の内径辺
１６舌片の内径辺の先鋭角部
２第２環状シート
２１第２環状シートの舌片
２３舌片の一端辺
２４舌片の他端辺
２５舌片の内径辺
２６舌片の内径辺の先鋭角部
３第１環状芯金
４第２環状芯金
５リベット[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an oil seal. The oil seal here is suitable for use in a relatively large size such as a work roll neck bearing of a rolling mill.
[0002]
[Prior art]
Generally, an oil seal is formed of a synthetic rubber or the like that is continuous in the circumferential direction, and the required sealing performance is managed by appropriately setting the contact pressure against a sliding contact partner such as a rotating shaft. ing.
[0003]
Sealing performance refers to preventing water, etc., existing in the external space from entering the sealed space, and discharging excess oil to the external space when there is excessive lubricating oil such as grease or oil in the sealed space. is there.
[0004]
[Problems to be solved by the invention]
By the way, in a relatively large oil seal such as a work roll neck bearing of a rolling mill, the sealing lip becomes rigid and the flexibility is lowered, so that the followability to the rotational runout of the rotating shaft tends to be deteriorated. Such poor followability means that a gap is easily formed between the rotating shaft and the outer peripheral surface of the rotating shaft, and water easily enters the sealed space from the gap. The trouble that it will become.
[0005]
Apart from this, for the purpose of reducing sliding contact resistance with the rotating shaft, the oil seal may be formed of a fluorine-based resin such as Teflon. Since the oil seal made of such a fluororesin is considerably harder than the synthetic rubber, it is pointed out that the followability to the rotational runout of the rotating shaft is poor even if it is not large as described above. A similar problem occurs.
[0006]
Accordingly, an object of the present invention is to make it possible to easily manufacture an oil seal, and to exhibit a stable sealing performance and a good followability to the rotational runout of a rotating shaft.
[0007]
[Means for Solving the Problems]
The first oil seal of the present invention is an oil seal that is brought into contact with the outer peripheral surface of the rotating shaft at an angle, and is a first annular sheet and a second annular sheet that are overlapped in the axial direction, and both annular sheets. The annular sheets are provided with tongue pieces projecting radially inward at required intervals in the circumferential direction, and a tongue piece and a tongue piece adjacent to the tongue piece are provided on both annular sheets . There is a space between them, the other end in the circumferential direction of the tongue piece is provided with a sharp corner portion which is the most central side of the inner peripheral surface of the annular sheet and protrudes toward the center side, and the first annular A notch of a required length is provided on the base side of the tongue piece of the sheet from the other circumferential end to the one circumferential end, the first annular seal is disposed on the sealed space side, and the second annular sheet Is disposed coaxially with the first annular sheet on the outer space side, By inserting the tongue of the second annular seat in said notch in the tongue of the annular seat, the previous sharp portion of the first annular sheet is in the axially outer space side of the tongue of the second annular sheet.
Further, in the first oil seal of the present invention, one end side of one end side in the circumferential direction of each tongue piece of both the annular sheets is inclined toward the other end side from the radially outer side toward the center side. preferable.
The second oil seal according to the present invention is an oil seal that is obliquely brought into contact with the outer peripheral surface of the rotating shaft, and is a first annular sheet and a second annular sheet that are overlapped in the axial direction, and both annular sheets. The annular sheets are provided with tongue pieces projecting radially inward at every required interval in the circumferential direction, and the tongue piece and the tongue piece adjacent to the tongue piece are provided. There is a space between them, and both ends of the tongue piece in the circumferential direction are provided with sharp corners or sharp projections, and the sharp corners or sharp projections are in the radial direction of the inner circumferential surface of each annular sheet. The innermost edge is located between the sharp corners or the sharp projections on both end sides of the tongue, and the first annular sheet is disposed on the outer space side, and the second annular sheet The sheet is disposed on the sealed space side, and the inner diameter side of the first annular sheet and the second annular sheet The first annular sheet and the second annular sheet are shifted in phase so that the radial sides do not overlap with each other in the circumferential direction, whereby the annular sheets that are mating to each other are separated from each other in the separation region between the adjacent tongue pieces of both annular sheets. The tongue is positioned.
In the second oil seal of the present invention, even if both end sides of the second annular sheet are inclined toward the inner diameter side from the radially outer side toward the center side than the sharp corner portion or the sharp convex portion of each tongue piece, Good.
In the second oil seal of the present invention, both end sides of the tongue pieces of the first annular sheet may be inclined toward the inner diameter side from the radially outer side toward the center side than the sharpened corner part or the sharpened convex part. Good.
[0008]
In the above oil seal, the coupling member can be constituted by two annular plates that sandwich the outer peripheral side of each annular sheet from both axial sides. In each tongue piece of both annular sheets, it is preferable that the end on the upstream side in the rotation direction of the rotation shaft is inclined in the rotation direction of the rotation shaft. It is preferable that the corner portion on the downstream side in the rotation direction of the rotation shaft on the inner diameter side of each tongue piece of both annular sheets projects sharply inward in the radial direction. One annular sheet is preferably provided with a cut having a required length from the downstream side in the rotational direction of the rotary shaft to the upstream side at the base of the tongue. In each tongue piece of the annular sheet on the sealed space side, it is preferable that one end side in the circumferential direction is inclined in the forward rotation direction of the rotation shaft and the other end side in the circumferential direction is inclined in the reverse rotation direction of the rotation shaft. In each tongue piece of the annular sheet on the outer space side, it is preferable that one end side in the circumferential direction is inclined in the forward rotation direction of the rotation shaft, and the other end side in the circumferential direction is inclined in the reverse rotation direction of the rotation shaft. It is preferable that the inner diameter side of each tongue piece of both annular sheets bend in a concave shape with the center in the circumferential direction as a trough, and set the curvature to be larger than the curvature of the inscribed circle diameter of each tongue piece.
[0009]
In the present invention, in short, the inner periphery of the annular sheet is not continuous in the circumferential direction, and tongue pieces are provided at circumferential positions on the inner periphery. By shifting and superimposing them in the axial direction, flexibility is provided.
[0010]
Moreover, since the oil seal of the present invention only couples the outer peripheral sides of the two annular sheets, it can be easily handled in manufacture and can be easily assembled.
[0011]
Furthermore, the oil seal of the present invention is capable of exhibiting excellent sealing performance such as excessive lubricating oil discharge and water intrusion prevention when limiting the rotation axis to only one of the forward and reverse rotation directions. A bi-directional rotating type that can be used as a one-way rotating type, or that can perform excellent sealing performance, such as discharging excess lubricant and preventing water from entering the rotating direction, regardless of whether the rotating shaft is rotating forward or backward. It can be done. In other words, by overlapping the end portions in the circumferential direction of the tongue pieces in the axial direction, a step is created in the overlapping portion of the adjacent tongue pieces and a minute gap is formed between the rotating shafts. It becomes a passage. However, the minute gap does not become a water intrusion passage because the lubricating oil exists and is closed after the lubricating oil is discharged.
[0012]
Moreover, in the present invention, the lubricating oil can be smoothly discharged by inclining the circumferential edge of the tongue piece in the rotational direction. Moreover, if the corner | angular part of a tongue piece is sharpened, it can jump off so that water may not go to the micro clearance gap as a discharge channel.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Details of the present invention will be described below based on the embodiments shown in FIGS.
[0014]
1 to 5 relate to a first embodiment of the present invention, FIG. 1 is a front view of an oil seal, FIG. 2 is a sectional view taken along line (2)-(2) in FIG. 1, and FIG. (3)-(3) cross-sectional arrow view of FIG. 2, FIG. 4 is an explanatory view showing the procedure of combining two annular sheets, and FIG. 5 is a view of the contact area of the oil seal with the rotating shaft viewed from the outer diameter side. FIG. In FIG. 1, the inner periphery of the oil seal A is illustrated as being straight, but in reality, the inner periphery is curved as illustrated in FIG. 2.
[0015]
In the figure, A shows the entire oil seal, and B is a rotating shaft. The oil seal A of this embodiment can exhibit a stable sealing performance in a situation where the rotating shaft B is rotated in one of the forward and reverse directions while giving flexibility as a structure in which two annular sheets are overlapped. This is a one-way rotation type.
[0016]
Specifically, the oil seal A is composed of two annular sheets 1 and 2 that are overlapped in the axial direction, and two annular core bars 3 and 4 that hold the annular sheets 1 and 2 in an overlapped state. Has been.
[0017]
The annular sheets 1 and 2 are provided with tongue pieces 11 and 21 that protrude inward in the radial direction at required intervals in the circumferential direction, and have substantially the same shape, but the tongue pieces 11 of the first annular sheet 1. A cut 12 having a required length is provided only on the base side from the downstream side in the rotation direction of the rotary shaft B to the upstream side. The tongue pieces 11 and 21 are substantially fan-shaped in plan view, and one end side (left side in the figure) 13 and 23 in the circumferential direction is inclined in one rotation direction (clockwise direction) of the rotation axis B, but the other end in the circumferential direction The sides (right side in the figure) 14, 24 are along the radial direction and are not inclined. In addition, the corners 16 and 26 on the other end side in the circumferential direction (right side in the figure) of the inner diameter sides 15 and 25 of the tongue pieces 11 and 21 protrude so as to be sharp, but one end side in the circumferential direction (left side in the figure). ) Corners 17 and 27 are tapered. The annular sheets 1 and 2 can be formed of a fluorine-based resin such as Teflon or a synthetic rubber.
[0018]
The cross-sections of the upper half of the annular core bars 3 and 4 are formed in an inverted L shape, and are composed of cylindrical portions 31 and 41 along the axial direction and annular plate portions 32 and 42 radially inward. Between the annular plate portions 32 and 42 of the annular core bars 3 and 4, the outer peripheral portions of the annular sheets 1 and 2 stacked in the axial direction are sandwiched. A rivet 5 for holding the annular sheets 1 and 2 sandwiched between the annular plate portions 32 and 42 and for integrating the two annular core bars 3 and 4 penetrates in the axial direction. It is attached in the state to do. A packing 6 is interposed between the second annular core 4 and the first annular sheet 1.
[0019]
And in the state which attached the cyclic | annular sheet | seats 1 and 2 to the cyclic | annular metal cores 3 and 4, the tongue pieces 11 and 21 of the cyclic | annular sheets 1 and 2 are made into the shape which contact | abuts diagonally with respect to the outer peripheral surface of the rotating shaft B. It is curved.
[0020]
A method for assembling such an oil seal A will be described. That is, as shown in FIG. 4, after the second annular sheet 2 is placed on the first annular sheet 1, the second annular sheet 2 is rotated by a required angle in one circumferential direction with respect to the first annular sheet 1. Thus, the tongue piece 21 of the second annular sheet 2 is inserted into the notch 12 of the tongue piece 11 of the first annular sheet 1. Thereby, the tongue piece 21 of the second annular sheet 2 is positioned in the separation region between the adjacent tongue pieces 11 of the first annular sheet 1. Then, the first annular cored bar 3 is placed on the workbench in a posture in which the outer surface of the annular plate part 32 faces downward, with respect to the inner surface of the annular plate part 32 of the first annular cored bar 3 as described above. The first and second annular sheets 1 and 2 combined together are placed. Thereafter, the cylindrical portion 41 of the second annular cored bar 4 is press-fitted into the cylindrical part 31 of the first annular cored bar 3 so that the annular plate parts 32 and 42 of the two annular cored bars 3 and 4 are annular. The outer peripheral side of the sheets 1 and 2 is clamped. In this state, the rivets 5 are sequentially attached.
[0021]
As described above, the oil seal A according to the first embodiment can be manufactured simply by sandwiching the punched annular sheets 1 and 2 between the annular core bars 3 and 4 and stopping them with the rivets 5. Therefore, the operation is simple and automatic. For example, it is possible to suppress as much as possible a wasteful increase in production cost.
[0022]
Next, the operation of the oil seal A will be described. In addition, the rotation direction of the rotating shaft B is limited to only clockwise as shown by the arrow in FIG. In the oil seal A, the tongue pieces 11 and 21 of the first and second annular sheets 1 and 2 are in contact with the outer peripheral surface of the rotating shaft B at approximately half the longitudinal direction on one side. In this state, as shown in FIG. 3, the gap between the tongue piece 11 of the first annular sheet 1 and the tongue piece 21 of the second annular sheet 2 is caused between the rotation axis B as shown in FIG. A minute gap is formed.
[0023]
In such an oil seal A, if the lubricating oil such as grease or oil existing in the sealed space is excessive, as shown by solid line arrows in FIG. 13 and 23 are guided downstream in the rotational direction, and are discharged to the outside through the minute gap. The minute gap is closed because the lubricating oil remains after the excessive lubricating oil is discharged.
[0024]
Further, when water is applied to the outer space side of the oil seal A, the water is caused by the inner diameter sides 15 and 25 and the sharp corners 16 and 26 of the tongue pieces 11 and 21 of the first and second annular sheets 1 and 2, respectively. As indicated by the one-dot chain line arrow in FIG. 5, the water is splashed away from the minute gap serving as the lubricating oil discharge passage, thereby preventing water from entering the sealed space.
[0025]
By the way, when rotational runout of the rotary shaft B occurs, the independent tongue pieces 11 and 21 of the oil seal A flex relatively flexibly as necessary to follow the runout of the rotary shaft B. No gap is formed between the two. Therefore, even when such a rotational shake of the rotary shaft B occurs, it is possible to prevent water from entering the sealed space from the external space.
[0026]
6 to 9 relate to a second embodiment of the present invention, FIG. 6 is a front view of an oil seal corresponding to FIG. 1, FIG. 7 is a diagram corresponding to FIG. 3, and FIG. FIG. 9 and FIG. 9 correspond to FIG.
[0027]
In the second embodiment, a bi-directional rotating type is employed in which stable sealing performance can be exhibited even when the rotating shaft B rotates in either the forward or reverse direction. Therefore, the shapes of the tongue pieces 11 and 21 of the annular sheets 1 and 2 are different from those of the first embodiment.
[0028]
Specifically, the first and second annular sheets 1 and 2 are slightly different in the shape of the tongue pieces 11 and 21, but the tongue pieces 11 and 21 are both symmetrical in the circumferential direction.
[0029]
The tongue piece 11 of the first annular sheet 1 is substantially fan-shaped in plan view, and one end side 13 in the circumferential direction is in the positive rotation direction (for example, clockwise) of the rotation axis B, and the other end side 14 in the circumferential direction is The rotation axis B is inclined at a required angle in the reverse rotation direction (for example, counterclockwise). Furthermore, the inner diameter side 15 of the tongue piece 11 is curved in a concave shape having a valley at the center in the circumferential direction, and the curvature thereof is set to be larger than the curvature of the inscribed circle diameter. The corners 16 and 17 at both ends in the circumferential direction are formed in a sharp shape.
[0030]
On the other hand, the tongue piece 21 of the second annular sheet 2 has a shape in which both circumferential ends of the tongue piece 11 of the first annular sheet 1 are extended. One end side 23 in the circumferential direction of the tongue piece 21 is in the forward rotation direction (for example, clockwise) of the rotation axis B, and the other end side 24 in the circumferential direction is in the reverse rotation direction (for example, counterclockwise direction) of the rotation axis B. The required angle is inclined. In addition, the inner diameter side 25 of the tongue piece 21 is formed in a corrugated shape that forms two sharp convex portions 26 and 27. The curvature of the region between the two sharp convex portions 26 and 27 in the inner diameter side 25 is set to be larger than the curvature of the inscribed circle diameter.
[0031]
A method for assembling such an oil seal A will be described. That is, the first annular cored bar 3 is placed on the workbench in a posture with the outer surface of the annular plate part 32 facing downward, and the first annular cored bar 3 is first placed against the inner surface of the annular plate part 32 of the first annular cored bar 3. The first annular sheet 1 is placed, and then the second annular sheet 2 is overlapped with the first annular sheet 1 while shifting the phase. The tongue piece 21 of the two annular sheet 2 is positioned. At this time, both ends of the tongue piece 21 of the second annular sheet 2 are overlapped with both ends of the tongue piece 11 of the first annular sheet 1. Thereafter, the cylindrical portion 41 of the second annular cored bar 4 is press-fitted into the cylindrical part 31 of the first annular cored bar 3 so that the annular plate parts 32 and 42 of the two annular cored bars 3 and 4 are annular. The outer peripheral side of the sheets 1 and 2 is clamped. In this state, the rivets 5 are sequentially attached.
[0032]
In this case, since the operation | work which integrates the 1st annular sheet 1 and the 2nd annular sheet 2 like the said Example 1 is unnecessary, it can manufacture now more easily.
[0033]
Next, the operation of the oil seal A is basically the same as that of the first embodiment. However, regardless of whether the rotation direction of the rotary shaft B is normal or reverse, the sealing performance such as discharge of excess lubricating oil and prevention of water intrusion is achieved. Is designed to perform well. It should be noted that the excessive lubricating oil flow occurs when the rotation direction of the rotation shaft B is clockwise, as indicated by the solid line arrow in FIG. 9, and when the rotation direction of the rotation shaft B is counterclockwise. As shown by the broken line arrows in FIG. When the rotation direction of the rotation axis B is clockwise, as shown by a one-dot chain line arrow in FIG. 9, and when the rotation direction of the rotation axis B is counterclockwise, the water flow is as shown in FIG. As shown by a two-dot chain arrow.
[0034]
In addition, this invention is not limited only to the said Example, Various application and deformation | transformation can be considered.
[0035]
(1) The number of the tongue pieces 11 and 21 of the annular sheets 1 and 2 may be arbitrarily set according to, for example, the outer diameter of the rotating shaft B.
[0036]
(2) Although two annular core bars 3 and 4 are used, only one of the annular core bars may be used, or the annular sheets 1 and 2 may be formed by using only the rivet 5 without using the annular core bar. May be combined. Furthermore, the rivet 5 may not be used if the two annular core bars 3 and 4 are joined relatively firmly only by press-fitting.
[0037]
(3) In Example 1 described above, the cuts 12 may not be provided in the first annular sheet 1.
[0038]
(4) In the second embodiment, the two annular sheets 1 and 2 are slightly different in shape, but the shapes of the two annular sheets 1 and 2 may be set exactly the same. In this case, since only one kind of the annular sheets 1 and 2 is sufficient, the production cost can be reduced.
[0039]
【The invention's effect】
In the present invention, a structure that stably exhibits sealing performance such as discharge of excess lubricating oil and prevention of water intrusion is provided, and the structure is made flexible so that followability to rotational runout of the rotating shaft is simplified, and the manufacturing is simplified. Therefore, the product price is reduced. In other words, the oil seal of the present invention can exhibit suitable sealing performance even when it is set to a relatively large outer diameter, or when it is made of a hard fluorine resin that reduces sliding contact resistance with the rotating shaft. become. In particular, in the present invention, since the two annular sheets can be manufactured simply by overlapping them, the manufacturing cost is significantly increased compared to the conventional one-piece structure, such as easy manufacturing and automation. Can be avoided.
[Brief description of the drawings]
1 is a front view of an oil seal according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line (2)-(2) in FIG. 1. FIG. 3 is a line (3)-(3) in FIG. FIG. 4 is an explanatory view showing a procedure for combining two annular sheets of the oil seal of the first embodiment. FIG. 5 is a view of the contact area of the oil seal of the first embodiment viewed from the outer diameter side. 6 is a front view of an oil seal according to a second embodiment of the present invention. FIG. 7 is a diagram corresponding to FIG. 3 in the second embodiment. FIG. 8 is a diagram corresponding to FIG. FIG. 5 is a diagram corresponding to FIG. 5 in the second embodiment.
A Oil seal B Rotating shaft 1 First annular sheet 11 Tongue piece 12 of first annular sheet 13 Notch 13 of first annular sheet One end side 14 of tongue piece 15 Other side 15 of tongue piece Inner side 16 of tongue piece Inner diameter of tongue piece Edge sharp edge 2 of the second annular sheet 21 Tongue piece 23 of the second annular sheet One end side 24 of the tongue piece 25 Other end side 25 of the tongue piece Inner side edge 26 of the tongue piece Sharp edge part 3 of the inner diameter side of the tongue piece Annular core 4 Second annular core 5 Rivet

Claims

An oil seal that is obliquely brought into contact with the outer peripheral surface of the rotating shaft,
A first annular sheet and a second annular sheet that are overlapped in the axial direction, and a coupling member that couples both annular sheets;
Each annular sheet is provided with a tongue piece projecting radially inward at a required interval in the circumferential direction , and has a separation region between the tongue piece and the tongue piece adjacent to the tongue piece, The other end in the circumferential direction of the tongue is provided with a sharp corner that is the most central of the inner circumferential surfaces of the annular sheet and protrudes toward the center, and on the base of the tongue of the first annular sheet A notch of a required length is provided from the other circumferential end to the one circumferential end, the first annular seal is disposed on the sealed space side, and the second annular seat is disposed on the outer space side. The tongue portion of the second annular sheet is inserted into the notch of the tongue piece of the first annular sheet, and the acute angle portion of the first annular sheet is the tongue of the second annular sheet. An oil seal characterized by being on the side of the outer space in the axial direction of the piece .

2. The oil seal according to claim 1, wherein one end side on one end side in the circumferential direction of each tongue piece of each of the annular sheets is inclined toward the other end side from the radially outer side toward the center side. .

An oil seal that is obliquely brought into contact with the outer peripheral surface of the rotating shaft,
A first annular sheet and a second annular sheet that are overlapped in the axial direction, and a coupling member that couples both annular sheets;
Each annular sheet is provided with a tongue piece projecting radially inward at a required interval in the circumferential direction, and has a separation region between the tongue piece and the tongue piece adjacent to the tongue piece, The tongue piece is provided with a sharp angle portion or a sharp convex portion at both ends in the circumferential direction, and the sharp corner portion or the sharp convex portion is located on the innermost side in the radial direction of the inner peripheral surface of each annular sheet, Between each sharp angle part or each sharp convex part on both ends of the inner diameter side,
The first annular sheet is disposed on the outer space side, and the second annular sheet is disposed on the sealed space side,
The first annular sheet and the second annular sheet are overlapped with each other by shifting the phases so that the inner diameter side of the first annular sheet and the inner diameter side of the second annular sheet do not overlap in the circumferential direction. An oil seal , characterized in that a tongue piece of an annular sheet which is a partner is positioned in a separation region between the matching tongue pieces .

The both end sides from the acute angle part or the sharp convex part of each tongue piece of the second annular sheet are inclined toward the inner diameter side from the radially outer side toward the central side. Oil seal.

The both end sides from the acute angle part or the sharp convex part of each tongue piece of the first annular sheet are inclined toward the inner diameter side from the radially outer side toward the center side. Oil seal as described in

The inner diameter side of each piece of both annular sheets is curved in a concave shape with the center in the circumferential direction as a valley, and the curvature is set to be larger than the curvature of the inscribed circle diameter of each tongue piece, The oil seal according to any one of claims 3 to 5, wherein:

The oil seal according to any one of claims 1 to 6, wherein the coupling member includes two annular plates that sandwich the outer peripheral side of each annular sheet from both axial sides .