JP4105379B2

JP4105379B2 - Wheel bearing

Info

Publication number: JP4105379B2
Application number: JP2000343550A
Authority: JP
Inventors: 寿志大槻; 孝幸乗松
Original assignee: NTN Corp
Current assignee: NTN Corp
Priority date: 2000-11-10
Filing date: 2000-11-10
Publication date: 2008-06-25
Anticipated expiration: 2020-11-10
Also published as: JP2002147474A

Description

【０００１】
【発明の属する技術分野】
この発明は、自動車等における車輪用軸受に関し、特に回転検出用のエンコーダ格子を一体化した車輪用軸受に関する。
【０００２】
【従来の技術と発明が解決しようとする課題】
従来、図５に示すように転動体１０３を介して転接する内方部材１０１および外方部材１０２間にシール装置１０５を設けた車輪用軸受において、シール装置１０５にエンコーダ格子１０６を一体化させたものが提案されている（例えば、特開平６−２８１０１８号）。シール装置１０５は、各々断面Ｌ字状とされた第１，第２のシール板１０７，１０８を内方部材１０１および外方部材１０２にそれぞれ嵌合させ、第２のシール板１０８にリップ１０９を設けたものである。第１のシール板１０７は、スリンガと呼ばれる。エンコーダ格子１０６は、磁性体粉が混入された弾性部材であり、第１のシール板１０７に加硫接着されている。エンコーダ格子１０６は、円周方向に交互に磁極が形成されたものであり、対面配置された磁気センサ１１０で検出される。
【０００３】
スリンガとなるシール板１０７と回転輪となる内方部材１０１とは、圧入状態に嵌合しているが、外部環境により、この嵌合部に錆が発生することがある。車輪用軸受は、路面状況等により泥水等が降りかかる厳しい環境下にあり、特に、塩泥水等がかかる環境下で使用される場合、錆が発生し易くなる。上記車輪用軸受では、内方部材１０１の外径面とエンコーダ格子１０６の内径面との間に隙間Ｇが生じる構造であるため、この隙間Ｇに錆が発生した場合、錆の成長に伴い、磁性ゴムからなるエンコーダ格子１０６のの内径面を押し広げることになり、磁気特性を劣化させる。そのため、磁気センサ１１０による検出精度の低下を招く恐れがある。
【０００４】
図６は、回転部材と静止部材間の密封装置において、エンコーダ格子を兼用させた他の例を示す（特開平６−２８１０１８号）。このシール装置１１５は、第１のシール板１０７の立板部１０７ｂに軸方向内方側に凹む凹所１０７ｂｂを設け、この凹所１０７ｂｂに一部が埋まるように、立板部１０７ｂの外向き面の略全体に磁性ゴムからなるエンコーダ格子１０６を設けている。また、エンコーダ格子１０６には、第１のシール板１０７が嵌合したシャフト１１１の外径面に先端が接触するリップ１０６ａが一体に形成してある。第２のシール板１０８は、ハウジングからなる外方部材１０２の内径面に嵌合させてある。
【０００５】
このシール装置１１５では、エンコーダ格子１０６のリップ１０６ａがシャフト１１１に接するため、第１のシール板１０７とシャフト１１１との嵌合部から軸方向内方側へ水や泥水が浸入することが阻止できる。しかし、リップ１０６ａによる水等の浸入阻止は、初期には効果が得られるが、ある程度の発錆が生じると、リップ１０６ａの有無によるシール効果の差がなくなるうえ、リップ１０６ａがエンコーダ格子１０６と一体であることから、成長した錆によりリップ１０６ａが押され、却ってエンコーダ格子１０６の変形への影響が大きくなる。
このため、どちらかと言うと、図５の例のように、磁性ゴムのエンコーダ格子１０６と、そのシール板１０７の嵌合した部材１０１との間に、相当量のラジアル隙間Ｇが形成されている方が、影響が少ない。しかし、この隙間Ｇを大きくすると、磁性ゴムのエンコーダ格子本体の面積が減少し、必要な磁気特性を得ることができなくなる。
【０００６】
この発明の目的は、シールと回転側部材との嵌合部で発生する錆によるエンコーダ格子の変形および磁性劣化を防止でき、またエンコーダ格子の面積が十分に得られて必要な磁気特性を確保することのできる車輪用軸受を提供することである。
【０００７】
【課題を解決するための手段】
この発明の車輪用軸受は、内方部材および外方部材と、これら内外の部材間に収容される複数の転動体と、上記内外の部材間の端部環状空間を密封するシール装置とからなり、
上記シール装置が、上記内方部材と外方部材のうちの互いに異なる部材に各々取付けられた第１および第２の環状のシール板を有し、両シール板は、各々円周部と立板部とでなる断面Ｌ字状に形成されて互いに対向し、第１のシール板は上記内方部材および外方部材のうちの回転側の部材に嵌合され、立板部は軸受外方側に配されると共に、この立板部に磁性体粉が混入された弾性部材が加硫接着されて、この弾性部材は周方向に交互に磁極が形成され、第２のシール板は他の弾性部材が加硫接着されてこの弾性部材の一部として上記立板部に摺接する１枚のサイドリップと円筒部に摺接する２枚のラジアルリップとを一体に有し、この第２のシール板の円筒部と上記第１のシール板の立板部の先端とを僅かな径方向間隔をもって対峙させた車輪用軸受において、
上記第１のシール板はステンレス製であって、その円筒部と立板部の間に軸受外方側に突曲する折曲重合部を有し、前記第１のシール板に加硫接着される弾性部材は、第１のシール板の立板部の軸方向外向きの面と前記折曲重合部との間で形成される凹所に、前記折曲重合部の突出端まで埋設し、上記２枚のラジアルリップは、互いに軸方向の内外に位置し、その内側のラジアルリップは先端が内側に向き、外側のラジアルリップは先端が外側に向き、上記第２のシール板に加硫接着された弾性部材は、第２のシール板の円筒部の内径面から先端外径面までを覆う先端覆い部を有することを特徴とする。
この構成によると、第１のシール板の立板部に、磁性体粉が混入された弾性部材が加硫接着され、周方向に交互に磁極が形成されているため、この弾性部材でいわゆるエンコーダ格子が構成され、これに対面する磁気センサで回転検出を行うことができる。
内外の部材間のシールについては、第２のシール板に設けられた各シールリップの摺接と、第２のシール板の円筒部に第１のシール板の立板部先端が僅かな径方向隙間で対峙することで構成されるラビリンスシールとで得られる。
第１のシール板には円筒部と立板部の間に軸受外方側に突曲する折曲重合部が設けられているので、第１のシール板の嵌合部と弾性部材とが折曲重合部で遮断されて、嵌合部で発生した錆が弾性部材の形成部に進展することが阻止される。回転側の部材における第１のシール板の嵌合部に錆が発生したとしても、その錆の成長により弾性部材が圧迫されることがない。そのため、錆の発生し易い厳しい環境下で使用されても、エンコーダ格子となる弾性部材の変形および磁性劣化を防止できる。また、折曲重合部は、湾曲部に比べて径方向の厚さが薄くて済み、そのためエンコーダ格子となる弾性部材の面積を大きく得ることができて、磁気特性の確保が容易となる。
【０００８】
この発明において、上記第１のシール板の立板部に設けた凹所の深さを、その第１のシール板の板厚よりも深くしても良い。
このように凹所を深く形成することにより、エンコーダ格子となる弾性部材の厚みを厚くすることができ、弾性部材の軸受外側に向く面が小さくても、磁気特性の確保が容易となる。
【００１０】
この発明において、上記折曲重合部の突出端面と上記回転側部材の端面とを略同一平面内に位置させても良い。
【００１１】
この発明において、上記弾性部材の軸受外方側に向く端面と上記回転側部材の端面とを略同一平面内に位置させても良い。
このように構成することにより、車輪用軸受の幅寸法を大きくすることなく弾性部材の厚みを十分確保できる。
【００１２】
この発明において、上記弾性部材の軸受外方側に向く端面が、上記第２のシール板の円筒部の軸受外方側に向く端面に対して、略同一平面内に位置し、または僅かに軸受内方側に後退しているものとしても良い。この構成の場合、上記弾性部材と第２のシール板の円筒部との間で、常に、所定軸方向幅のラビリンスシールが維持され、シール性が向上する。また、弾性部材を後退させるだけで良いため、シール板に複雑な形状の加工を施すことが不要で、シール板の形状が簡素なもので済み、また密封手段の配置空間を大きくすることなく、シール性を向上させることができる。
【００１４】
【発明の実施の形態】
この発明の基礎となる提案例を図１〜図３と共に説明する。この提案例は、駆動輪の支持に用いる車輪用軸受に適用した例であって、着磁エンコーダがシールスリンガを兼用した例である。
図１に示すように、この車輪用軸受は、内方部材１および外方部材２と、これら内外の部材１，２間に収容される複数の転動体３と、内外の部材１，２間の端部環状空間を密封するシール装置５，１３とを備える。一端のシール装置５は、着磁エンコーダ２０付きのものである。内方部材１および外方部材２は、転動体３の軌道面１ａ，２ａを有しており、各軌道面１ａ，２ａは溝状に形成されている。内方部材１および外方部材２は、各々転動体３を介して互いに回転自在となった内周側の部材および外周側の部材のことであり、軸受内輪および軸受外輪の単独であっても、これら軸受内輪や軸受外輪と別の部品とが組合わさった組立部材であっても良い。また、内方部材１は、軸であっても良い。転動体３は、ボールまたはころからなり、この例ではボールが用いられている。
【００１５】
この車輪用軸受は、複列の転がり軸受、詳しくは複列のアンギュラ玉軸受とされていて、その軸受内輪は、各転動体列の軌道面１ａ，１ａがそれぞれ形成された一対の分割型の内輪１Ａ，１Ｂからなる。これら内輪１Ａ，１Ｂは、ハブ輪６の軸部の外周に嵌合し、ハブ輪６と共に上記内方部材１を構成する。なお、内方部材１は、上記のようにハブ輪６および一対の分割型の内輪１Ａ，１Ｂからなる３部品の組立部品とする代わりに、ハブ輪６および片方の内輪１Ｂが一体化された軌道面付きのハブ輪と、もう片方の内輪１Ａとで構成される２部品からなるものとしても良い。
【００１６】
ハブ輪６には、等速自在継手７の一端（例えば外輪）が連結され、ハブ輪６のフランジ部６ａに車輪（図示せず）がボルト８で取付けられる。等速自在継手７は、その他端（例えば内輪）が駆動軸に連結される。
外方部材２は、軸受外輪からなり、懸架装置におけるナックル等からなるハウジング（図示せず）に取付けられる。転動体３は各列毎に保持器４で保持されている。
【００１７】
図３は、着磁エンコーダ付きのシール装置５を拡大して示す。このシール装置５は、内方部材１と外方部材２に各々取付けられた第１および第２の環状のシール板１１，１２を有する。これらシール板１１，１２は、各々内方部材１および外方部材２に圧入状態に嵌合させることで取付けられている。両シール板１１，１２は、各々円筒部１１ａ，１２ａと立板部１１ｂ，１２ｂとでなる断面Ｌ字状に形成されて互いに対向する。
第１のシール板１１は、内方部材１および外方部材２のうちの回転側の部材である内方部材１に嵌合され、スリンガとなる。第１のシール板１１の立板部１１ｂは、軸受外方側に配され、その外方側の側面に、磁性体粉が混入された弾性部材１４が加硫接着されている。この弾性部材１４は、第１のシール板１１と共に着磁エンコーダ２０を構成するエンコーダ格子となるものであり、周方向に交互に磁極Ｎ，Ｓ（図２）が形成され、いわゆるゴム磁石とされている。磁極Ｎ，Ｓは、ピッチ円直径（ＰＣＤ）において、所定のピッチｐとなるように形成されている。この着磁エンコーダ２０の弾性部材１４に対面して、同図のように磁気センサ１５を配置することにより、車輪回転速度の検出用のロータリエンコーダが構成される。
弾性部材１４は、第１のシール板１１の立板部１１ｂの先端部から先端内側面を覆う先端覆い部１４ａを有している。なお、この先端覆い部１４ａは、省略しても良い。
【００１８】
第２のシール板１２は、第１のシール板１１の立板部１１ｂに摺接するサイドリップ１６ａと円筒部１１ａに摺接するラジアルリップ１６ｂ，１６ｃとを一体に有する。これらリップ１６ａ〜１６ｃは、第２のシール板１２に加硫接着された弾性部材１６の一部として設けられている。図３の例では、１枚のサイドリップ１６ａと、軸方向の内外に位置する２枚のラジアルリップ１６ｃ，１６ｂとを設けている。第２のシール板１２は、固定側部材である外方部材２との嵌合部に弾性部材１６を抱持したものとしてある。すなわち、弾性部材１６は、円筒部１２ａの内径面から先端部外径までを覆う先端覆い部１６ｄを有するものとし、この先端覆い部１６ｄが、第２のシール板１２と外方部材２との嵌合部に介在する。第２のシール板１２の円筒部１２ａの先端部１２ａａは、円筒部１２ａの他の部分よりも薄肉とされて斜め内径側へ屈曲しており、この屈曲した先端部１２ａａを先端覆い部１６ｄが覆っている。
【００１９】
第２のシール板１２の円筒部１２ａと第１のシール板１１の立板部１１ｂの先端とは僅かな径方向隙間をもって対峙させ、その隙間でラビリンスシール１７を構成している。第１，第２のシール板１１，１２の弾性部材１４，１６に先端覆い部１４ａ，１６ｄを設けた場合は、これら先端覆い部１４ａ，１６ｄ間の隙間が上記ラビリンスシール１７を構成する隙間となる。
【００２０】
第１のシール板１１の立板部１１ｂには、軸受内方側に凹む凹所１１ｂｂが設けられ、この凹所１１ｂｂに弾性部材１４が埋設されている。その凹所１１ｂｂの深さは、第１のシール板１１の板厚よりも深く設定されている。この提案例の場合、第１のシール板１１の円筒部１１ａと立板部１１ｂの間に軸受外方側に突曲する湾曲部１１ｃが形成され、この湾曲部１１ｃの突出端面は回転側の部材である内方部材１の端面と略同一平面内に位置している。すなわち、この車輪用軸受の軸心に対する同一の垂直面内に略位置している。
また、弾性部材１４の軸受外方側に向く端面は、回転側の部材である内方部材１の端面に対しても、略同一平面内に位置している。
さらに、弾性部材１４の軸受外方側に向く端面は、第２のシール板１２の円筒部１２ａの軸受外方側に向く端面に対して、略同一平面内に位置させるか、または僅かに軸受内方側に後退させてある。
【００２１】
各部材の材質例を説明する。内方部材１、外方部材２、および転動体３は、いずれも軸受鋼等の炭素鋼からなる。第１のシール板１１は、磁性体でかつ防錆性を有する鋼板であり、強磁性体等の磁性体の鋼板、例えばフェライト系のステンレス鋼板（ＪＩＳ規格のＳＵＳ４３０系等）が用いられる。第２のシール板１２は、鋼板、例えば非磁性体であるオーステナイト系のステンレス鋼板（ＳＵＳ３０４系等）や、防錆処理された圧延鋼板等が用いられる。例えば、第１のシール板１１をフェライト系のステンレス鋼板とし、第２のシール板１２をオーステナイト系のステンレス鋼板としても良い。
【００２２】
この構成の車輪用軸受によると、第１のシール板１１の立板部１１ｂに、磁性体粉の混入された弾性部材１４が加硫接着され、周方向に交互に磁極Ｎ，Ｓが形成されているため、この弾性部材１４と第１のシール板１１とでパルサリングとなる着磁エンコーダ２０が構成され、弾性部材１４に対面する磁気センサ１５で回転検出を行うことができる。
内外の部材１，２間のシールについては、第２のシール板１２に設けられた各シールリップ１６ａ〜１６ｃの摺接と、第２のシール板１２の円筒部１２ａに第１のシール板１１の立板部１１ｂの先端が僅かな径方向隙間で対峙することで構成されるラビリンスシール１７とで得られる。
【００２３】
スリンガとなる第１のシール板１１の立板部１１ｂには軸受内方側に凹む凹所１１ｂｂが設けられ、この凹所１１ｂｂにエンコーダ格子となる弾性部材１４が埋設されているので、回転側部材である内方部材１における第１のシール板１１の円筒部１１ａの嵌合部に錆が発生したとしても、その錆の成長により弾性部材１４が圧迫されることがなく、弾性部材１４の変形および磁性劣化を防止できる。したがって、磁気センサ１５による回転検出精度が維持される。
また、第１のシール板１１の立板部１１ｂに設けた凹所１１ｂｂの深さは、その第１のシール板１１の板厚よりも深くされているので、弾性部材１４の全体を凹所１１ｂｂ内に設けながら、弾性部材１４の肉厚を十分に得ることができる。そのため、弾性部材１４の軸方向に向く面の面積が小さくても、磁気特性を確保することができる。
第１のシール板１１の円筒部１１ａと立板部１１ｂとの間には、軸受外方側に突曲する湾曲部１１ｃが形成されていて、この湾曲部１１ｃの突出端面が回転側部材である内方部材１の端面と略同一平面内に位置させてあるので、内方部材１における第１のシール板１１の嵌合部に発生した錆が弾性部材１４に進展するのを阻止できる。湾曲部１１ｃは、第１のシール板１１の剛性を増大する補強効果を得ることもできる。
弾性部材１４の軸受外方側に向く端面は、回転側部材である内方部材１の端面と略同一平面内とされているので、この点でも、内方部材１における第１のシール板１１の嵌合部に発生した錆が、弾性部材１４に進展することが阻止される。
【００２４】
防錆性能を向上させるために、第１のシール板１１は、磁性体で、かつ防錆性を有する鋼板で形成するのが好ましい。このように磁性体で、かつ、防錆性を有する鋼板により第１のシール板１１を形成することにより、着磁エンコーダの磁気コアとなる第１のシール板１１において十分な磁束密度を確保できると共に、この第１のシール板１１と回転側部材である内方部材１との嵌合部での防錆性が向上する。
【００２５】
図４は、この発明の一実施形態を示す。上記提案例では、第１のシール板１１における円筒部１１ａと立板部１１ｂとの間に、軸受外方側に突曲する湾曲部１１ｃを形成したが、この実施形態では、上記湾曲部１１ｃに代えて、軸受外方側に突曲する折曲重合部１１ｄを形成し、その折曲重合部１１ｄの突出端面が回転側部材である内方部材１の端面と略同一平面となるようにする。
このように構成した場合、内方部材１における第１のシール板１１の嵌合部に発生した錆が弾性部材１４に進展することを折曲重合部１１ｄによって阻止することができる。また、折曲重合部１１ｄは、湾曲部１１ｃに比べて径方向の厚さが薄くて済み、そのためエンコーダ格子となる弾性部材１４の面積を大きく得ることができて、磁気特性の確保が容易となる。
【００２６】
【発明の効果】
この発明の車輪用軸受は、スリンガとなる第１のシール板の円筒部と立板部の間に軸受外方側に突曲する折曲重合部を有し、前記第１のシール板に加硫接着される弾性部材は、第１のシール板の立板部の軸方向外向きの面と前記折曲重合部との間で形成される凹所に、前記折曲重合部の突出端まで埋設したため、回転側の部材における第１のシール板の嵌合部に錆が発生したとしても、その錆の成長により弾性部材が圧迫されることがなく、エンコーダ格子となる弾性部材の変形および磁性劣化を防止できる。そのため、厳しい環境下で使用されても、エンコーダ格子の検出による回転検出精度が維持される。
【図面の簡単な説明】
【図１】この発明の基礎となる提案例にかかる車輪用軸受を設置した車輪支持装置の断面図である。
【図２】そのエンコーダ格子となる弾性部材の部分正面図である。
【図３】同車輪用軸受の部分断面図である。
【図４】この発明の一実施形態にかかる車輪用軸受の部分断面図である。
【図５】従来例の断面図である。
【図６】他の従来例の断面図である。
【符号の説明】
１…内方部材
２…外方部材
３…転動体
５…シール装置
１１…第１のシール板
１１ｂｂ…凹所
１１ｃ…湾曲部
１１ｄ…折曲重合部
１２…第２のシール板
１１ａ，１２ａ…円筒部
１１ｂ，１２ｂ…立板部
１４…弾性部材
１６ａ〜１６ｃ…リップ部
Ｎ，Ｓ…磁極[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wheel bearing in an automobile or the like, and more particularly to a wheel bearing integrated with an encoder grid for detecting rotation.
[0002]
[Prior art and problems to be solved by the invention]
Conventionally, in a wheel bearing in which a seal device 105 is provided between an inner member 101 and an outer member 102 that are in rolling contact with each other via a rolling element 103 as shown in FIG. 5, an encoder lattice 106 is integrated with the seal device 105. Some have been proposed (for example, JP-A-6-281018). The sealing device 105 has first and second sealing plates 107 and 108 each having an L-shaped cross section fitted to the inner member 101 and the outer member 102, respectively, and a lip 109 is attached to the second sealing plate 108. It is provided. The first seal plate 107 is called a slinger. The encoder lattice 106 is an elastic member mixed with magnetic powder, and is vulcanized and bonded to the first seal plate 107. The encoder grating 106 is formed by alternately forming magnetic poles in the circumferential direction, and is detected by the magnetic sensor 110 arranged face-to-face.
[0003]
The seal plate 107 serving as a slinger and the inner member 101 serving as a rotating ring are fitted in a press-fit state, but rust may be generated in the fitting portion depending on the external environment. The wheel bearing is in a severe environment where muddy water or the like falls depending on the road surface condition or the like, and particularly when used in an environment where salt muddy water or the like is applied, rust is likely to occur. In the wheel bearing, since the gap G is generated between the outer diameter surface of the inner member 101 and the inner diameter surface of the encoder grating 106, when rust is generated in the gap G, along with the growth of rust, The inner diameter surface of the encoder grating 106 made of magnetic rubber is expanded to deteriorate the magnetic characteristics. For this reason, the detection accuracy of the magnetic sensor 110 may be reduced.
[0004]
FIG. 6 shows another example in which the encoder grating is also used in the sealing device between the rotating member and the stationary member (Japanese Patent Laid-Open No. Hei 6-281018). This sealing device 115 is provided with a recess 107bb that is recessed inward in the axial direction in the standing plate portion 107b of the first sealing plate 107, and the standing plate portion 107b faces outward so that a part thereof is buried in the recess 107bb. An encoder grid 106 made of magnetic rubber is provided on substantially the entire surface. The encoder lattice 106 is integrally formed with a lip 106a whose tip contacts the outer diameter surface of the shaft 111 with which the first seal plate 107 is fitted. The second seal plate 108 is fitted to the inner diameter surface of the outer member 102 made of a housing.
[0005]
In this sealing device 115, since the lip 106a of the encoder lattice 106 contacts the shaft 111, it is possible to prevent water and muddy water from entering the axially inward side from the fitting portion between the first seal plate 107 and the shaft 111. . However, the prevention of intrusion of water or the like by the lip 106a is effective in the initial stage, but if a certain amount of rusting occurs, the difference in the sealing effect due to the presence or absence of the lip 106a is eliminated, and the lip 106a is integrated with the encoder grid 106 Therefore, the lip 106a is pushed by the grown rust, and the influence on the deformation of the encoder grating 106 is increased.
For this reason, a considerable amount of radial gap G is formed between the encoder lattice 106 of magnetic rubber and the member 101 fitted with the seal plate 107, as in the example of FIG. The effect is less. However, if the gap G is increased, the area of the magnetic rubber encoder grid body decreases, and the required magnetic characteristics cannot be obtained.
[0006]
The object of the present invention is to prevent deformation and magnetic deterioration of the encoder grid due to rust generated at the fitting portion between the seal and the rotation side member, and to ensure sufficient magnetic properties by sufficiently obtaining the area of the encoder grid. It is providing the wheel bearing which can be performed.
[0007]
[Means for Solving the Problems]
The wheel bearing according to the present invention includes an inner member and an outer member, a plurality of rolling elements accommodated between the inner and outer members, and a seal device that seals the end annular space between the inner and outer members. ,
The sealing device includes first and second annular sealing plates respectively attached to different members of the inner member and the outer member, and both the sealing plates have a circumferential portion and a vertical plate, respectively. The first seal plate is fitted to the rotating member of the inner member and the outer member, and the upright plate portion is on the outer side of the bearing. In addition, an elastic member in which magnetic powder is mixed is vulcanized and bonded to the standing plate portion, the magnetic poles are alternately formed in the circumferential direction of the elastic member, and the second seal plate is made of another elastic material. The second seal plate is integrally provided with one side lip that is slidably contacted with the upright plate portion and two radial lips that are slidably contacted with the cylindrical portion as a part of the elastic member after the member is vulcanized and bonded. The cylindrical portion of the first seal plate and the tip of the upright plate portion of the first seal plate are opposed to each other with a slight radial interval. In the wheel bearing,
The first seal plate is made of stainless steel, and has a bent overlapping portion that protrudes outward from the bearing between the cylindrical portion and the upright plate portion, and is vulcanized and bonded to the first seal plate. The elastic member is embedded in a recess formed between the axially outward surface of the upright plate portion of the first seal plate and the bent overlapping portion up to the protruding end of the bent overlapping portion, The two radial lips are positioned inward and outward in the axial direction, the inner radial lip is pointed inward, the outer radial lip is pointed outward, and vulcanized and bonded to the second seal plate. The elastic member has a tip cover portion that covers from the inner diameter surface to the outer diameter surface of the cylindrical portion of the second seal plate.
According to this configuration, the elastic member mixed with the magnetic powder is vulcanized and bonded to the standing plate portion of the first seal plate, and the magnetic poles are alternately formed in the circumferential direction. A lattice is formed, and rotation detection can be performed by a magnetic sensor facing the lattice.
Regarding the seal between the inner and outer members, the sliding contact of each seal lip provided on the second seal plate and the front end of the first seal plate on the cylindrical portion of the second seal plate are slightly in the radial direction. It is obtained with a labyrinth seal constructed by confronting with a gap.
Since the first seal plate is provided with a bent overlapping portion that protrudes outwardly from the bearing between the cylindrical portion and the standing plate portion, the fitting portion of the first seal plate and the elastic member are folded. It is interrupted | blocked by a bending superposition | polymerization part, and it prevents that the rust which generate | occur | produced in the fitting part progresses to the formation part of an elastic member. Even if rust is generated at the fitting portion of the first seal plate in the rotation side member, the elastic member is not pressed by the growth of the rust. Therefore, even when used in a harsh environment where rust is likely to occur, deformation of the elastic member serving as the encoder lattice and magnetic deterioration can be prevented. In addition, the bending overlapping portion only needs to be thinner in the radial direction than the bending portion. Therefore, the area of the elastic member serving as the encoder lattice can be increased, and the magnetic characteristics can be easily ensured.
[0008]
In the present invention, the depth of the recess provided in the standing plate portion of the first seal plate may be deeper than the thickness of the first seal plate.
By forming the recesses deeply in this way, it is possible to increase the thickness of the elastic member serving as the encoder lattice, and it is easy to ensure the magnetic characteristics even if the surface of the elastic member facing the outside of the bearing is small.
[0010]
In the present invention, but it may also be allowed to position the end face of the projecting end surface and the rotation-side member of the bent polymerization unit in substantially the same plane.
[0011]
In the present invention, the end face of the elastic member facing the bearing outward side and the end face of the rotating side member may be positioned in substantially the same plane.
By comprising in this way, sufficient thickness of an elastic member is securable, without enlarging the width dimension of the wheel bearing.
[0012]
In the present invention, the end face of the elastic member facing the bearing outward side is located substantially in the same plane with respect to the end face of the cylindrical portion of the second seal plate facing the bearing outward side or is slightly in the bearing. It may be retreated inward. In the case of this configuration, a labyrinth seal having a predetermined axial width is always maintained between the elastic member and the cylindrical portion of the second seal plate, and the sealing performance is improved. In addition, since it is only necessary to retract the elastic member, it is not necessary to process a complicated shape on the seal plate, the shape of the seal plate is simple, and without increasing the arrangement space of the sealing means, Sealability can be improved.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
An example of a proposal that is the basis of the present invention will be described with reference to FIGS. This proposed example is an example applied to a wheel bearing used to support a drive wheel, and an example in which a magnetized encoder also serves as a seal slinger.
As shown in FIG. 1, the wheel bearing includes an inner member 1 and an outer member 2, a plurality of rolling elements 3 accommodated between the inner and outer members 1 and 2, and the inner and outer members 1 and 2. Sealing devices 5 and 13 for sealing the end annular space. The sealing device 5 at one end has a magnetizing encoder 20. The inner member 1 and the outer member 2 have raceway surfaces 1a and 2a of the rolling element 3, and each raceway surface 1a and 2a is formed in a groove shape. The inner member 1 and the outer member 2 are an inner peripheral member and an outer peripheral member that are rotatable with respect to each other via the rolling elements 3, respectively. An assembly member in which the bearing inner ring and the bearing outer ring are combined with another component may be used. Further, the inner member 1 may be a shaft. The rolling element 3 consists of a ball or a roller, and a ball is used in this example.
[0015]
This wheel bearing is a double-row rolling bearing, more specifically, a double-row angular contact ball bearing, and the inner ring of the bearing is a pair of split type in which the raceway surfaces 1a and 1a of the respective rolling element rows are respectively formed. It consists of inner rings 1A and 1B. The inner rings 1 </ b> A and 1 </ b> B are fitted to the outer periphery of the shaft portion of the hub wheel 6 and constitute the inner member 1 together with the hub wheel 6. The inner member 1 is integrated with the hub wheel 6 and one inner ring 1B instead of the three-piece assembly part including the hub ring 6 and the pair of split inner rings 1A and 1B as described above. It is good also as what consists of two components comprised by the hub ring with a raceway surface, and the other inner ring | wheel 1A.
[0016]
One end (for example, an outer ring) of the constant velocity universal joint 7 is connected to the hub wheel 6, and a wheel (not shown) is attached to the flange portion 6 a of the hub wheel 6 with a bolt 8. The other end (for example, inner ring) of the constant velocity universal joint 7 is connected to the drive shaft.
The outer member 2 includes a bearing outer ring, and is attached to a housing (not shown) including a knuckle or the like in the suspension device. The rolling elements 3 are held by a holder 4 for each row.
[0017]
FIG. 3 shows an enlarged view of the sealing device 5 with a magnetized encoder. The sealing device 5 includes first and second annular sealing plates 11 and 12 attached to the inner member 1 and the outer member 2, respectively. The seal plates 11 and 12 are attached to the inner member 1 and the outer member 2 by being fitted in a press-fitted state. Both seal plates 11 and 12 are formed in an L-shaped cross section composed of cylindrical portions 11a and 12a and upright plate portions 11b and 12b, and face each other.
The first seal plate 11 is fitted to the inner member 1 which is a rotating side member of the inner member 1 and the outer member 2, and becomes a slinger. The standing plate portion 11b of the first seal plate 11 is disposed on the bearing outer side, and an elastic member 14 mixed with magnetic powder is vulcanized and bonded to the outer side surface. This elastic member 14 becomes an encoder lattice that constitutes the magnetized encoder 20 together with the first seal plate 11, and magnetic poles N and S (FIG. 2) are alternately formed in the circumferential direction, which is a so-called rubber magnet. ing. The magnetic poles N and S are formed to have a predetermined pitch p in the pitch circle diameter (PCD). By facing the elastic member 14 of the magnetized encoder 20 and arranging the magnetic sensor 15 as shown in the figure, a rotary encoder for detecting the wheel rotation speed is configured.
The elastic member 14 has a tip cover portion 14 a that covers the tip inner surface from the tip portion of the standing plate portion 11 b of the first seal plate 11. In addition, you may abbreviate | omit this front end cover part 14a.
[0018]
The second seal plate 12 integrally includes a side lip 16a that is in sliding contact with the standing plate portion 11b of the first seal plate 11 and radial lips 16b and 16c that are in sliding contact with the cylindrical portion 11a. These lips 16a~16c is that provided as part of the second sealing plate 12 bonded by vulcanization to the elastic member 16. In the example of FIG. 3, one side lip 16a and two radial lips 16c and 16b positioned inside and outside in the axial direction are provided. The second seal plate 12 is configured such that an elastic member 16 is held in a fitting portion with the outer member 2 that is a fixed side member. That is, the elastic member 16 has a tip cover portion 16d that covers from the inner diameter surface of the cylindrical portion 12a to the outer diameter of the tip portion, and this tip cover portion 16d is formed between the second seal plate 12 and the outer member 2. Intervenes in the fitting part. The distal end portion 12aa of the cylindrical portion 12a of the second seal plate 12 is thinner than the other portions of the cylindrical portion 12a and is bent toward the oblique inner diameter side. The bent distal end portion 12aa is covered by a distal end covering portion 16d. that covered.
[0019]
The cylindrical portion 12a of the second seal plate 12 and the tip of the standing plate portion 11b of the first seal plate 11 are opposed to each other with a slight radial gap, and the labyrinth seal 17 is configured by the gap. When the tip cover portions 14 a and 16 d are provided on the elastic members 14 and 16 of the first and second seal plates 11 and 12, the gap between the tip cover portions 14 a and 16 d is the gap constituting the labyrinth seal 17. Become.
[0020]
The standing plate portion 11b of the first seal plate 11 is provided with a recess 11bb that is recessed inward of the bearing, and an elastic member 14 is embedded in the recess 11bb. The depth of the recess 11bb is set deeper than the thickness of the first seal plate 11. In the case of this proposed example , a curved portion 11c that projects outwardly from the bearing is formed between the cylindrical portion 11a and the upright plate portion 11b of the first seal plate 11, and the projecting end surface of the curved portion 11c is on the rotation side. It is located in the substantially same plane as the end surface of the inner member 1 which is a member. That is, it is substantially located in the same vertical plane with respect to the axis of the wheel bearing.
Further, the end face of the elastic member 14 facing the outer side of the bearing is located in substantially the same plane with respect to the end face of the inner member 1 that is a member on the rotation side.
Further, the end face of the elastic member 14 facing the bearing outward side is positioned substantially in the same plane with respect to the end face of the cylindrical portion 12a of the second seal plate 12 facing the bearing outward side, or is slightly in the bearing. It is retracted inward.
[0021]
An example of the material of each member will be described. The inner member 1, the outer member 2, and the rolling element 3 are all made of carbon steel such as bearing steel. The first seal plate 11 is a steel plate that is a magnetic material and has rust prevention properties, and a magnetic steel plate such as a ferromagnetic material, for example, a ferritic stainless steel plate (JIS standard SUS430 or the like ) is used. The second seal plate 12 is made of a steel plate, for example, an austenitic stainless steel plate (SUS304 type or the like) that is a non-magnetic material, a rust-proof rolled steel plate, or the like. For example, the first seal plate 11 may be a ferritic stainless steel plate, and the second seal plate 12 may be an austenitic stainless steel plate.
[0022]
According to the wheel bearing of this configuration, the elastic member 14 mixed with magnetic powder is vulcanized and bonded to the standing plate portion 11b of the first seal plate 11, and the magnetic poles N and S are alternately formed in the circumferential direction. Thus, the elastic member 14 and the first seal plate 11 constitute a magnetizing encoder 20 that becomes pulsar ring, and rotation detection can be performed by the magnetic sensor 15 facing the elastic member 14.
Regarding the seal between the inner and outer members 1, 2, the first seal plate 11 is brought into sliding contact with the seal lips 16 a to 16 c provided on the second seal plate 12 and the cylindrical portion 12 a of the second seal plate 12. It is obtained by the labyrinth seal 17 comprised by the front-end | tip of the standing plate part 11b facing each other with a slight radial clearance.
[0023]
The standing plate portion 11b of the first seal plate 11 serving as a slinger is provided with a recess 11bb recessed inward of the bearing, and an elastic member 14 serving as an encoder lattice is embedded in the recess 11bb. Even if rust is generated in the fitting portion of the cylindrical portion 11a of the first seal plate 11 in the inner member 1 which is a member, the elastic member 14 is not compressed by the growth of the rust, and the elastic member 14 Deformation and magnetic deterioration can be prevented. Therefore, the rotation detection accuracy by the magnetic sensor 15 is maintained.
Further, since the depth of the recess 11bb provided in the standing plate portion 11b of the first seal plate 11 is deeper than the thickness of the first seal plate 11, the entire elastic member 14 is recessed. While providing in 11bb, the thickness of the elastic member 14 can be sufficiently obtained. Therefore, even if the area of the surface facing the axial direction of the elastic member 14 is small, the magnetic characteristics can be ensured.
Between the cylindrical portion 11a and the upright plate portion 11b of the first seal plate 11, there is formed a curved portion 11c that bends outwardly of the bearing, and the protruding end surface of the curved portion 11c is a rotation side member. Since the inner member 1 is positioned in substantially the same plane as the end surface of the inner member 1, it is possible to prevent rust generated at the fitting portion of the first seal plate 11 in the inner member 1 from progressing to the elastic member 14. The curved portion 11 c can also obtain a reinforcing effect that increases the rigidity of the first seal plate 11.
Since the end surface of the elastic member 14 facing the bearing outer side is substantially in the same plane as the end surface of the inner member 1 that is the rotation side member, the first seal plate 11 in the inner member 1 is also in this respect. The rust generated in the fitting portion is prevented from progressing to the elastic member 14.
[0024]
In order to improve the rust prevention performance, the first seal plate 11 is preferably formed of a magnetic material and a steel plate having rust prevention properties. Thus, by forming the 1st seal board 11 with the magnetic body and the steel plate which has rust prevention property, sufficient magnetic flux density can be ensured in the 1st seal board 11 used as the magnetic core of a magnetization encoder. At the same time, the rust prevention property at the fitting portion between the first seal plate 11 and the inner member 1 which is the rotation side member is improved.
[0025]
FIG. 4 shows an embodiment of the present invention. In the proposed example , the curved portion 11c that protrudes outward from the bearing is formed between the cylindrical portion 11a and the upright plate portion 11b of the first seal plate 11, but in this embodiment, the curved portion 11c is bent. instead, to form a folded overlapping portion 11d for projecting curved axially受外hand side, so that the projecting end face of that occasion songs polymerization unit 11d is an end surface substantially flush of the inner member 1 is rotatable member to.
Thus constituted case, it is possible to first seal plate 11 rust generated in the fitting portion of the inner member 1 is prevented by folding overlapping portion 11d that develop into the elastic member 14. Further, the bending overlap portion 11d has a smaller radial thickness than the bending portion 11c, so that the area of the elastic member 14 serving as the encoder lattice can be increased, and the magnetic characteristics can be easily ensured. Become.
[0026]
【The invention's effect】
The wheel bearing of the present invention has a bent overlapping portion that protrudes outward from the bearing between the cylindrical portion and the standing plate portion of the first seal plate serving as a slinger, and is added to the first seal plate. The elastic member to be sulfur bonded is in a recess formed between the axially outward surface of the upright plate portion of the first seal plate and the bent overlapping portion, up to the protruding end of the bent overlapping portion. Even if rust is generated at the fitting portion of the first seal plate in the rotating side member, the elastic member is not compressed by the growth of the rust, and the deformation and magnetic properties of the elastic member serving as the encoder lattice are prevented. Deterioration can be prevented. Therefore, even when used in a harsh environment, the rotation detection accuracy by detecting the encoder grating is maintained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a wheel support device provided with wheel bearings according to a proposed example as the basis of the present invention.
FIG. 2 is a partial front view of an elastic member serving as the encoder lattice.
FIG. 3 is a partial sectional view of the wheel bearing.
FIG. 4 is a partial cross-sectional view of a wheel bearing according to an embodiment of the present invention.
FIG. 5 is a cross-sectional view of a conventional example.
FIG. 6 is a cross-sectional view of another conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Inner member 2 ... Outer member 3 ... Rolling body 5 ... Sealing device 11 ... 1st sealing board 11bb ... Recess 11c ... Curved part 11d ... Bending superposition | polymerization part 12 ... 2nd sealing board 11a, 12a ... Cylindrical part 11b, 12b ... Standing plate part 14 ... Elastic members 16a-16c ... Lip part N, S ... Magnetic pole

Claims

An inner member and an outer member, a plurality of rolling elements housed between these inner and outer members, and a sealing device for sealing the end annular space between the inner and outer members,
The sealing device includes first and second annular sealing plates respectively attached to different members of the inner member and the outer member, and both the sealing plates have a circumferential portion and a vertical plate, respectively. The first seal plate is fitted to the rotating member of the inner member and the outer member, and the upright plate portion is on the outer side of the bearing. In addition, an elastic member mixed with magnetic powder is vulcanized and bonded to the upright plate portion, the magnetic pole is alternately formed in the circumferential direction of the elastic member, and the second seal plate is made of another elastic material. The second seal plate is integrally provided with one side lip that is slidably contacted with the upright plate part and two radial lips that are slidably contacted with the cylindrical part as a part of the elastic member after the member is vulcanized and bonded. The cylindrical portion of the first seal plate and the tip of the upright plate portion of the first seal plate are opposed to each other with a slight radial interval. In the wheel bearing,
The first seal plate is made of stainless steel, and has a bent overlapping portion that protrudes outward from the bearing between the cylindrical portion and the upright plate portion, and is vulcanized and bonded to the first seal plate. The elastic member is embedded in a recess formed between the axially outward surface of the upright plate portion of the first seal plate and the bent overlapping portion up to the protruding end of the bent overlapping portion, The two radial lips are positioned inward and outward in the axial direction, the inner radial lip is pointed inward, the outer radial lip is pointed outward, and vulcanized and bonded to the second seal plate. The formed elastic member has a tip cover portion that covers from the inner diameter surface of the cylindrical portion of the second seal plate to the outer diameter surface of the tip.

The wheel bearing according to claim 1, wherein the depth of the recess formed in the standing plate portion of the first seal plate is deeper than the plate thickness of the first seal plate.

The wheel bearing according to claim 1 or 2, wherein the protruding end surface of the bent overlapping portion and the end surface of the rotating side member are positioned in substantially the same plane.

The end face facing the bearing outer side of the elastic member vulcanized and bonded to the first seal plate is substantially in the same plane with respect to the end face facing the bearing outer side of the cylindrical portion of the second seal plate. The wheel bearing according to any one of claims 1 to 3, wherein the wheel bearing is positioned or slightly retracted toward the inside of the bearing.