JP3905398B2

JP3905398B2 - Drive wheel bearing device

Info

Publication number: JP3905398B2
Application number: JP2002045753A
Authority: JP
Inventors: 英児田島; 茂明福島; 光梅木田
Original assignee: NTN Corp
Current assignee: NTN Corp
Priority date: 2002-02-22
Filing date: 2002-02-22
Publication date: 2007-04-18
Anticipated expiration: 2022-02-22
Also published as: JP2003246203A

Description

【０００１】
【発明の属する技術分野】
本発明は、自動車等の駆動車輪を支持する駆動車輪用軸受装置に関するもので、特に、ハブ輪と等速自在継手と複列の転がり軸受とをユニット化した駆動車輪用軸受装置に関するものである。
【０００２】
【従来の技術】
近年、自動車の懸架装置に対して車輪を回転自在に支持する車輪用軸受装置は、燃費向上のための軽量化が進んでいる。特に、ＦＦ車の前輪、ＦＲ車の後輪、およびＲＲ車の後輪、あるいは４ＷＤ車の全輪といった自動車の駆動車輪用軸受装置においては、さらに操縦安定性のための剛性アップを図るためのユニット化が急速に進んでいる。
【０００３】
こうした駆動車輪用軸受装置として例えば特開平６−１９３６４５号公報に記載されたものが知られている。図７は、この公報に記載された従来構造の第１例を示している。この駆動車輪用軸受装置は、ハブ輪５１と、このハブ輪５１に配置した等速自在継手５２の外側継手部材５５と、この外側継手部材５５を介してハブ輪５１に緊締した複列の転がり軸受５３とを備え、外側継手部材５５がハブ輪５１側の開口６７内に底部材５７を嵌合すると共に、この底部材５７にボルト５６を螺合し、ハブ輪５１と等速自在継手５２を分離可能に結合している。
【０００４】
底部材５７は、外側継手部材５５と結合した後に、この外側継手部材５５の内部における継手組立のために必要な空間を有しているので、等速自在継手５２を完全に組立てた後に、ハブ輪５１と外側継手部材５５とを結合することができる。したがって、装置の車両への組立作業を簡便にできると共に、等速自在継手５２の中心と複列の転がり軸受５３との間隔が短縮でき、軽量化を達成することができる。さらに、この結合部に負荷されるモーメント荷重を低減することができ、装置の耐久性を向上させることができる。
【０００５】
ハブ輪５１は、一端部に車輪（図示せず）を取付けるための車輪取付フランジ５４と、円筒状の小径段部５１ｂと、他端部には雄セレーション６２を有している。一方、複列の転がり軸受５３は、ハブ輪５１の小径段部５１ｂに圧入され、外周に内側転走面５９ａを形成した一対の内輪５９、５９と、内周にこの内側転走面５９ａ、５９ａに対向する複列の外側転走面６０ａ、６０ａを一体に形成した外方部材６０と、これらの転走面６０ａ、５９ａ間に収容した複列の転動体６１、６１とからなっている。ここで、図面下半分に示すように、内側転走面５９ａ、５９ａのうち一方をハブ輪５１の外周に直接形成した内側転走面５１ａとする場合もある。
【０００６】
また、等速自在継手５２は、外側継手部材５５と、継手内輪６３とケージ６５と、トルク伝達ボール６４とからなる。外側継手部材５５は中空をなし、カップ状のマウス部６６と、このマウス部６６の底部をなす肩部５８とを有している。この肩部５８の内周にはハブ輪５１の雄セレーション６２に係合する雌セレーション６８を形成し、エンジンからのトルクを、この外側継手部材５５を介してハブ輪５１に伝達している。
【０００７】
ここで、複列の転がり軸受５３を所望の内部すきまに設定し、内輪５９の端面を外側継手部材５５の肩部５８に当接させて位置決め固定すると共に、肩部５８の開口６７に嵌合した底部材５７とボルト５６からなる連結手段で荷重を負荷している。
【０００８】
【発明が解決しようとする課題】
この従来の駆動車輪用軸受装置では、複列の転がり軸受５３に負荷される荷重を、外側継手部材５５の肩部５８を介して底部材５７とボルト５６で受ける構造のため、底部材５７だけでなくボルト５６自体もそれ相当の強度を確保する必要があり、装置の軽量化には未だ制約があった。さらに、底部材５７の変形やボルト５６の伸び、あるいは螺合部の緩み等で軸受すきまが変動する恐れもあり、軸受寿命の面で問題を内在していた。
【０００９】
本発明は、このような事情に鑑みてなされたもので、大きなモーメント荷重が装置に作用しても結合部に緩みが発生せず、かつ装置の剛性向上が図れると共に、複列の転がり軸受と等速自在継手とを容易に分離でき、軽量・コンパクト化を達成することができる駆動車輪用軸受装置を提供することを目的としている。
【００１０】
【課題を解決するための手段】
係る目的を達成すべく、本発明のうち請求項１記載の発明は、内方部材と複列の転がり軸受と等速自在継手とをユニット化した駆動車輪用軸受装置であって、前記内方部材は、一端部に車輪取付フランジを有するハブ輪と、前記複列の転がり軸受の少なくとも一方の内側転走面を有する内輪とを有し、前記等速自在継手の外側継手部材に形成した雌セレーションを介して回転トルクを前記ハブ輪に伝達すると共に、前記内方部材と前記外側継手部材の間に、軸方向に分離可能な連結手段を設けた駆動車輪用軸受装置において、前記外側継手部材の雌セレーションに係合する雄セレーションを外周に形成した連結部材で、前記ハブ輪と複列の転がり軸受とを分離不可にユニット化すると共に、前記連結手段が鋼鈑プレス成形により形成したシールプレートを有し、このシールプレートの大径部を前記外側継手部材に係合し、小径部を前記内方部材に着脱可能に係合した構成を採用した。
【００１１】
このように、連結部材でハブ輪と複列の転がり軸受とを分離不可にユニット化したので、軸受すきまを所望の負すきまに管理、維持する、所謂セルフリテイン構造でサブユニット化でき、装置の組立性を格段に簡便化できると共に、シールプレート等の連結手段には大きな負荷はかからないので、連結手段を強固なものにする必要はなく、シールプレートを鋼鈑のプレス成形で形成でき、低コスト化と一層の軽量化を図ることができる。さらに、シールプレートの大径部を外側継手部材に係合し、小径部を内方部材に着脱可能に係合したので、装置の組立性を簡便化できるだけでなく、補修時に内方部材と等速自在継手とを分離することができ、補修費用を軽減することができる。
【００１２】
また、請求項２に記載の発明のように、前記内方部材が、前記複列の転がり軸受の一方の内側転走面を一体に形成したハブ輪と、他方の内側転走面を形成した内輪と、これらハブ輪と内輪を外嵌し、一端部を前記内輪の端面に係合すると共に、他端部を前記ハブ輪の端部に結合した連結部材とを備えていれば、従来のように、固定ボルト等の締付トルクを管理して軸受のすきま調整をする必要がなく、装置の組立性を格段に簡便化できる。さらに、軸受すきまが変動することもないため、安定した軸受寿命を長期間維持することができる。
【００１３】
また、請求項３に記載の発明のように、前記内方部材が、前記ハブ輪と、前記複列の転がり軸受の内側転走面を形成した一対の内輪と、これらハブ輪と内輪を外嵌し、一端部を前記内輪の端面に係合すると共に、他端部を前記ハブ輪の端部に結合した連結部材とを備えていれば、インボード側の内輪だけでなく、アウトボード側の内輪に転がり疲労寿命に優れたＳＵＪ２等の高炭素クロム鋼を使用することができると共に、ハブ輪に鍛造加工性に優れ、転動疲労寿命を考慮した高価な材料でなく、比較的廉価な材料を選択することができるため、装置の低コスト化を図ることができる。
【００１４】
また、請求項４に記載の発明のように、前記ハブ輪の内周に硬化した凹凸部を形成し、この凹凸部に前記連結部材の結合部を内嵌すると共に、この結合部を拡径して前記凹凸部に食い込ませ、前記ハブ輪と前記連結部材とを一体に塑性結合すれば、大きなモーメント荷重が装置に作用しても結合部に緩みが発生せず、耐久性を向上させることができる。
【００１５】
また、請求項５に記載の発明のように、前記連結部材と前記ハブ輪とを一体に形成し、このハブ輪の端部を前記内輪の端部に結合した構成を採用すると、部品点数を削減することができ、装置の低コスト化と、一層の軽量・コンパクト化を達成することができる。
【００１６】
好ましくは、請求項６に記載の発明のように、前記内輪の内周に硬化した凹凸部を形成し、この凹凸部に前記ハブ輪の結合部を内嵌すると共に、この結合部を拡径して前記凹凸部に食い込ませ、前記内輪と前記ハブ輪とを一体に塑性結合すれば、凹凸部の硬化処理を内輪の内側転走面等の硬化処理と同時に廉価なズブ焼入れを適用することができる。
【００１７】
また、前記連結手段が、請求項７に記載の発明のように、前記シールプレートと、このシールプレートの小径部に螺合する固定ボルトとを有し、この固定ボルトの頭部を前記ハブ輪の端部に係合するようにしても良いし、また、請求項８に記載の発明のように、前記シールプレートと、このシールプレートの小径部に螺合する固定ナットとを有し、この固定ナットを前記ハブ輪の端部に係合するようにしても良い。
【００１８】
また、請求項９に記載の発明のように、前記シールプレートの小径部が複数の爪部を有し、この爪部を前記内方部材の内周に形成した環状の係止溝に弾性的に係合するようにすれば、ワンタッチで内方部材と外側継手部材とを着脱することができ、部品点数を削減できて低コスト化を図ることができると共に、装置の組立性を簡便化できる。
【００１９】
【発明の実施の形態】
以下、本発明の実施の形態を図面に基づいて詳細に説明する。図１（ａ）は、本発明に係る駆動車輪用軸受装置の第１の実施形態を示す縦断面図である。
【００２０】
この駆動車輪用軸受装置は、内方部材１と、複列の転がり軸受８と、等速自在継手２０とをユニット化して構成している。なお、以下の説明では、車両に組み付けた状態で車両の外側寄りとなる側をアウトボード側（図面左側）、中央寄り側をインボード側（図面右側）という。
【００２１】
内方部材１は、ハブ輪２と、このハブ輪２と突き合せ状態で配設した別体内輪３と、これらハブ輪２と内輪３を連結する連結部材４とからなる。ハブ輪２のアウトボード側端部には車輪（図示せず）を取付けるための車輪取付フランジ５をを有し、この車輪取付フランジ５には、円周等配位置に車輪締結用のハブボルト６を植設している。また、ハブ輪２の外周には、後述する複列の転がり軸受８の一方の内側転走面２ａを形成し、この内側転走面２ａに続き軸方向に延びる円筒部７を一体に有している。この円筒部７の端面７ａと衝合する内輪３の外周には、複列の転がり軸受８の他方の内側転走面３ａを形成している。
【００２２】
一方、外方部材１０は、内周に前記内側転走面２ａ、３ａに対向する複列の外側転走面１０ａ、１０ａを一体に形成し、外周には車体に取付けるための車体取付フランジ１０ｂを一体に有している。複列の転がり軸受８は、この外方部材１０と前記した内方部材１、および、これら外方部材１０と内方部材１間に収容した複列の転動体９、９を主たる構成としている。複列の転動体９、９を、合成樹脂を射出成形してなるスナップオン形式の保持器１１によって転動自在に保持すると共に、複列の転がり軸受８の端部には、外部からの雨水やダストの侵入と、軸受内部に充填した潤滑グリースの流出を防止するためのシール１２、１３を装着している。この複列の転がり軸受８は、転動疲労寿命向上と剛性アップのために、その内部すきまを負に設定している。ここで、転動体９、９をボールとした複列アンギュラ玉軸受を例示したが、これに限らず転動体に円すいころを使用した複列円すいころ軸受であっても良い。
【００２３】
ハブ輪２の端部内周面には凹凸部１４を形成し、熱処理によって表面硬さを５８〜６４ＨＲＣの範囲に硬化層を形成している。熱処理として、その有効硬化層深さを比較的容易に調整できる高周波誘導加熱による焼入れが好適である。この凹凸部１４は、複数列の溝を交叉させたアヤメローレット状に形成している。また、凹凸部１４の凸部は食い込み性を確保するために、四角錐等の尖端形状に形成している。
【００２４】
連結部材４は、内輪３の端面に当接し位置決め固定する鍔部４ａと、この鍔部４ａから軸方向に延びる小径段部４ｂと、この小径段部４ｂの先端部に結合部４ｃを有している。また、鍔部４ａの外周には雄レーション（またはスプライン）１５を形成している。連結部材４において、このセレーション１５と、少なくとも内輪３に当接する鍔部４ａには、熱処理により表面硬さを５８〜６４ＨＲＣの範囲に硬化層を形成し、耐摩耗性と捩じり強度を向上させている。そして、ハブ輪２の内周に形成した凹凸部１４に結合部４ｃを内嵌し、この結合部４ｃの内径にマンドレルを挿入・抜脱させる等、適宜な手段で拡径して凹凸部１４に食い込ませる。したがって、結合部４ｃは鍛造後の素材硬さ２８ＨＲＣ以下の未焼入れ部とし、凹凸部１４の表面硬さ５８〜６４ＨＲＣとの硬度差３０ＨＲＣ以上に設定するのが好ましい。これにより、結合部４ｃが凹凸部１４に容易に、かつ深く食い込み、凹凸部１４の先端が潰れることなく強固にハブ輪２と連結部材４を塑性結合することができる。
【００２５】
ここではハブ輪２と連結部材４を拡径加締による塑性結合を例示したが、これに限らず、例えば、連結部材４の端部を径方向外方に塑性変形させ、ハブ輪２の端面に加締めて塑性結合する、所謂端面加締構造であっても良い。また、ハブ輪２と連結部材４との端部を電子ビーム溶接等で一体結合しても良い。
【００２６】
前述したハブ輪２は、Ｓ５３Ｃ等の炭素０．４０〜０．８０ｗｔ％を含む中炭素鋼で形成し、シール１２のリップが摺接するシールランド部、内側転走面２ａ、および円筒部７の端面７ａに亙って熱処理によって表面硬さを５８〜６４ＨＲＣの範囲に硬化層を形成し、耐摩耗性と疲労寿命を向上させている。また、内輪３はＳＵＪ２等の高炭素クロム鋼をズブ焼入れにより硬化し、耐摩耗性と疲労寿命を向上させている。
【００２７】
等速自在継手２０は外側継手部材２１と図示しない継手内輪２２、ケージ２３、およびトルク伝達ボール２４とからなる。外側継手部材２１はカップ状のマウス部２５、このマウス部２５から軸方向に延びる中空の肩部２６を有している。マウス部２５の内周には軸方向に延びる曲線状のトラック溝２１ａを形成し、このトラック溝２１ａに対向し、継手内輪２２の外周には曲線状のトラック溝２２ａを形成している。これらトラック溝２１ａ、２２ａの曲率中心は、継手中心に対して互いに軸方向に等距離だけオフセットしている。したがって、両トラック溝２１ａ、２２ａ間に収容したトルク伝達ボール２４を、如何なる作動角においても常にその作動角の二等分面上に保持して等速性を確保している。
【００２８】
外側継手部材２１の肩部２６内周には、前述した雄セレーション１５に噛合する雌セレーション（またはスプライン）２７を形成し、エンジンからのトルクを、この外側継手部材２１を介して連結部材４、およびハブ輪２に伝達している。ここで、雌セレーション２７を鍔部４ａの高さ分、内輪３の内径よりも大径に形成したので、その分歯数を多くできる。したがって、許容伝達トルクを低下させることなく、雌セレーション２７の幅を短くでき、等速自在継手２０の中心と複列の転がり軸受８との間隔を短縮でき、軽量化を達成することができる。さらに、この結合部に負荷されるモーメント荷重を低減することができ、装置の耐久性を向上させることができる。ここで、連結部材４の雄セレーション１５を未焼入れとし、軸線に対して僅かに傾斜させて形成し、雌セレーション２７に噛合することにより弾性変形させ、周方向の予圧によって歯面の耐摩耗性向上とセレーション部のガタを抑制するようにしても良い。
【００２９】
また、図１（ｂ）に拡大して示すように、肩部２６の端面には、前記インボード側のシール１３のリップ１６ａが摺接し、肩部２６と内輪３との当接部から雨水やダストがセレーション部に侵入し、発錆するのを防止している。シール１３は、内輪３に外嵌するＬ字状断面をなすスリンガ１６と、このスリンガ１６に対向配置し、同じくＬ字状断面をなすシール部材１７とからなり、このシール部材１７には、スリンガ１６の内周面に摺接するサイドリップ１７ａとラジアルリップ１７ｂを加硫接着等で溶着している。前記リップ１６ａは、先端に向け径方向外方に傾斜し、スリンガ１６の外周面に一体溶着している。
【００３０】
外側継手部材２１は、Ｓ５３Ｃ等の炭素０．４０〜０．８０ｗｔ％を含む中炭素鋼で形成し、前記トラック溝２１ａと肩部２６、およびセレーション２７を高周波焼入れによって硬さ５８〜６４ＨＲＣの範囲に表面硬化層を形成し、耐摩耗性と疲労寿命を向上させている。なお、外側継手部材２１をＳＣｒ４３０等の肌焼き鋼で形成し、全表面に浸炭焼入れによる硬化層を形成することもできる。
【００３１】
１８はシールプレートで、鋼鈑をプレス成形によってハット状に形成している。このシールプレート１８の大径部１８ａは、連結部材４の端面に対峙して外側継手部材２１のアウトボード側開口部２８に嵌合し、外部から雨水やダストの侵入と、等速自在継手２０内に充填した潤滑グリースが外部へ流出するのを防止すると共に、内方部材１と外側継手部材２１とを結合している。
【００３２】
シールプレート１８は、大径部１８ａと小径部１８ｂを溶接で一体に形成し、この小径部１８ｂを連結部材４の内径に嵌合すると共に、中心部に形成したねじ部に固定ボルト１９を螺合し、この固定ボルト１９の頭部をハブ輪２のアウトボード側端面にワッシャ１９ａを介して係合させ、内方部材１と外側継手部材２１とを着脱可能に結合している。ここでは、内方部材１における内輪３を、連結部材４の鍔部４ａで軸方向に結合し、ハブ輪２の凹凸部１４に連結部材４の結合部４ｃを食い込ませて塑性結合したので、軸受すきまを所望の負すきまに管理、維持する、所謂セルフリテイン構造でサブユニット化できる。したがって、複列の転がり軸受８に負荷された曲げモーメント荷重は、ハブ輪２の円筒部７と連結部材４の小径段部４ｂとの円筒嵌合部で受け、スラスト荷重やラジアル荷重によって誘起されるスラスト荷重はこの鍔部４ａで受けることになる。故に、シールプレート１８や固定ボルト１９には大きな負荷はかからないので、シールプレート１８や固定ボルト１９を強固なものにする必要はなく、一層の軽量化を図ることができる。また、従来のように、固定ボルト１９の締付トルクを管理して軸受のすきま調整をする必要もなく、装置の組立性を格段に簡便化できる。さらに、ここではワッシャ１９ａにロッキングワッシャを採用し、固定ボルト１９の緩みを防止しているが、万一この固定ボルト１９が緩んでも軸受すきまが変動することはないため、安定した軸受寿命を長期間維持することができる。
【００３３】
図２は本発明に係る駆動車輪用軸受装置の第２の実施形態を示す縦断面図である。図１に例示した実施形態と異なる点は、ハブ輪とシールプレートの構成のみで、前述した第１の実施形態と同一部位、同一部品には同一符号を付け、その詳細な説明を省略する。
【００３４】
この駆動車輪用軸受装置は、内方部材１’と、複列の転がり軸受８’と、等速自在継手２０とをユニット化して構成している。内方部材１’は、ハブ輪２’と内輪３、２９、および連結部材４とからなり、ハブ輪２’は車輪（図示せず）を取付けるための車輪取付フランジ５を有している。また、連結部材４の小径段部４ｂには別体の内輪３、２９を圧入し、ハブ輪２’と鍔部４ａによってこれら内輪３、２９を挟持して軸方向に位置決め固定している。また、ハブ輪２’の内周に形成した凹凸部１４に連結部材４の結合部４ｃを嵌合し、この結合部４ｃの内径を拡径して凹凸部１４に食い込ませて塑性結合し、ハブ輪２’と連結部材４とを一体に結合している。複列の転がり軸受８’は、外方部材１０とこれら一対の内輪３、２９と、それぞれの転走面１０ａ、２９ａと１０ａ、３ａ間に収容した複列の転動体９、９とからなる。ここでは、インボード側の内輪３よりもアウトボード側の内輪２９を幅広に形成し、耐曲げモーメント荷重を向上させた構成を例示したが、これに限らず、同一幅の一対の内輪で構成しても良い。
【００３５】
この第２の実施形態では、インボード側の内輪３だけでなく、アウトボード側の内輪２９に転がり疲労寿命に優れたＳＵＪ２等の高炭素クロム鋼を使用することができると共に、ハブ輪２’に鍛造加工性に優れ、転動疲労寿命を考慮した高価な材料でなく、比較的廉価な材料を選択することができるため、装置の低コスト化を図ることができる。
【００３６】
シールプレート１８’は、大径部１８ａと小径部１８ｂ’を一体に鋼鈑をプレス加工して形成している。なお、固定ボルト１９をこの小径部１８ｂ’に形成したねじ部に螺合する際、シールプレート１８’の供回りを防止するため、円筒状の小径部１８ｂ’の外周に係止部（図示せず）を形成し、連結部材４の内径に係止させても良い。
【００３７】
図３は、本発明に係る駆動車輪用軸受装置の第３の実施形態を示す縦断面図である。なお、前述した第１の実施形態と異なる点は、シールプレートを含めた結合部材のみで、その他同一部位、同一部品には同一符号を付け、その詳細な説明を省略する。
【００３８】
３０は外側継手部材２１のアウトボード側開口部２８に嵌合したシールプレートで、鋼鈑をプレス成形によってハット状に形成している。このシールプレート３０の大径部３１は、連結部材４の端面に対峙して外側継手部材２１のアウトボード側開口部２８に嵌合し、外部から雨水やダストの侵入と、等速自在継手２０内に充填した潤滑グリースが外部へ流出するのを防止している。大径部３１と、ねじ部３２ａを先端に有する円筒状の小径部３２とを溶接して一体に形成している。ねじ部３２ａには固定ナット３３を螺合し、ワッシャ３３ａを介してハブ輪２に係合して内方部材１と外側継手部材２１とを結合している。こうした構造を採用することにより、装置の組立性を向上させ、一層の軽量化を図ることができる。なお、３３ｂは固定ナット３３に装着したキャップで、中空の嵌合部３２内に外部から雨水やダストが侵入し、発錆するのを防止している。
【００３９】
図４は、本発明に係る駆動車輪用軸受装置の第４の実施形態を示す縦断面図である。なお、前述した第１の実施形態と異なる点は、シールプレートを含めた結合部材のみで、その他同一部位、同一部品には同一符号を付け、その詳細な説明を省略する。
【００４０】
３４はシールプレートで、鋼鈑をプレス成形によってハット状に形成している。このシールプレート３４の大径部３１は、連結部材４の端面に当接して外側継手部材２１のアウトボード側開口部２８に嵌合し、外部から雨水やダストの侵入と、等速自在継手２０内に充填した潤滑グリースが外部へ流出するのを防止している。この大径部３１と、係止部３６を先端に有する円筒状の小径部３５とを溶接して一体に形成している。係止部３６は、小径部３５に軸方向に延びる複数のスリット３６ａを形成し、これらスリット３６ａ、３６ａ間の爪部３６ｂを径方向外方に膨出させている。一方、連結部材４’の内周には環状の係止溝３７を形成し、この爪部３６ｂを弾性変形させて装着して内方部材１と外側継手部材２１とを結合している。こうした構造を採用することにより、装置の組立性をさらに向上させ、一層の軽量化を図ることができる。なお、３８はハブ輪２の開口部に装着したキャップで、内方部材１内に外部から雨水やダストが侵入し、発錆するのを防止している。
【００４１】
次に、このシールプレート３４を連結部材４’の内径に脱着する方法を、図５を用いて説明する。（ａ）はシールプレート３４の係止部３６を示し、スリット３６ａ、３６ａ間の爪部３６ｂは、自然な状態では円筒状の小径部３５の外径から膨出して大径に形成している。シールプレート３４を連結部材４’のインボード側開口部から挿入すると、スリット３６ａの間隔が狭くなるのと相俟ってこの爪部３６ｂが（ｂ）に示すように弾性変形し、爪部３６ｂが縮径する。さらにシールプレート３４を連結部材４’の係止溝３７位置まで挿入すると、この爪部３６ｂが復元して係止溝３７にワンタッチで係止させることができる。なお、係止溝３７を鋸刃状に形成しているので、シールプレート３４は、振動等で外れることはなく、安定して内方部材１と外側継手部材２１とを結合することができる。
【００４２】
一方、シールプレート３４を外す場合は、（ｃ）に示すように、連結部材４’の内径に分離治具Ｚを矢印の方向に嵌挿し、先端に形成した凹所のテーパ部Ｚ１で、係止部３６の先端部３６ｃを押圧し、スリット３６ａを狭め、爪部３６ｂを縮径させて係止溝３７から外す。
【００４３】
この第４の実施形態では、シールプレート３４のみで内方部材１と外側継手部材２１とをワンタッチで結合することができ、装置の組立性を格段に簡便化することができる。また、前述した固定ボルト１９や固定ナット３３が不要となるため、一層の低コスト化と軽量化を達成することができる。
【００４４】
図６は、本発明に係る駆動車輪用軸受装置の第５の実施形態を示す縦断面図である。なお、前述した第１の実施形態と異なる点は、内方部材のみで、その他同一部位、同一部品には同一符号を付け、その詳細な説明を省略する。
【００４５】
この駆動車輪用軸受装置は、内方部材１”と、複列の転がり軸受８”と、等速自在継手２０とをユニット化して構成している。内方部材１”は、ハブ輪２”と内輪３’とからなり、ハブ輪２”は車輪（図示せず）を取付けるための車輪取付フランジ５を有している。また、ハブ輪２”の外周には複列の転がり軸受８”の一方の内側転走面２ａと、この内側転走面２ａから軸方向に延びる円筒状の小径段部３９と、その先端に結合部３９ａを一体に形成している。
【００４６】
内輪３’をハブ輪２”の小径段部３９に圧入し、この内輪３’の端部に延設した連結部４０の外周には、雄セレーション１５を、また、内周には凹凸部４１を形成している。また、内輪３’はＳＵＪ２等の高炭素鋼からなり、ズブ焼きによって５８〜６４ＨＲＣの範囲に硬化させている。この凹凸部４１は、複数列の溝を交叉させたアヤメローレット状に形成し、食い込み性を確保するために四角錐等の尖端形状に形成している。
【００４７】
ハブ輪２”の結合部３９ａは、鍛造後の素材硬さ２８ＨＲＣ以下の未焼入れ部とし、内輪３’の内周に形成した凹凸部４１の表面硬さ５８〜６４ＨＲＣとの硬度差３０ＨＲＣ以上に設定するのが好ましい。これにより、結合部３９ａが凹凸部４１に容易に、かつ深く食い込み、凹凸部４１の先端が潰れることなく強固にハブ輪２”と内輪３’とを塑性結合することができる。
【００４８】
また、ハブ輪２”は、Ｓ５３Ｃ等の炭素０．４０〜０．８０ｗｔ％を含む中炭素鋼で形成し、前記結合部３９ａを残し、シール１２のリップが摺接するシールランド部、内側転走面２ａ、および小径段部３９に亙って熱処理によって表面硬さを５８〜６４ＨＲＣの範囲に硬化層を形成し、耐摩耗性と疲労寿命を向上させている。
【００４９】
こうした第４の実施形態では、前述したものと異なり、ハブ輪２”の小径段部３９を延長し、内輪３’と直接塑性結合して、ハブ輪２”と内輪３’とを一体に結合したため、前述した他の実施形態における連結部材４、４’が不要となる。したがって、一層、軽量・コンパクト化を達成することができる。
【００５０】
以上、本発明の実施の形態について説明を行ったが、本発明はこうした実施の形態に何等限定されるものではなく、あくまで例示であって、本発明の要旨を逸脱しない範囲内において、さらに種々なる形態で実施し得ることは勿論のことであり、本発明の範囲は、特許請求の範囲の記載によって示され、さらに特許請求の範囲に記載の均等の意味、および範囲内のすべての変更を含む。
【００５１】
【発明の効果】
以上詳述したように、本発明に係る駆動車輪用軸受装置は、内方部材と複列の転がり軸受と等速自在継手とをユニット化した駆動車輪用軸受装置であって、前記内方部材は、一端部に車輪取付フランジを有するハブ輪と、前記複列の転がり軸受の少なくとも一方の内側転走面を有する内輪とを有し、前記等速自在継手の外側継手部材に形成した雌セレーションを介して回転トルクを前記ハブ輪に伝達すると共に、前記内方部材と前記外側継手部材の間に、軸方向に分離可能な連結手段を設けた駆動車輪用軸受装置において、前記外側継手部材の雌セレーションに係合する雄セレーションを外周に形成した連結部材で、前記ハブ輪と複列の転がり軸受とを分離不可にユニット化すると共に、前記連結手段が鋼鈑プレス成形により形成したシールプレートを有し、このシールプレートの大径部を前記外側継手部材に係合し、小径部を前記内方部材に着脱可能に係合した構成を採用したので、軸受すきまを所望の負すきまに管理、維持する、所謂セルフリテイン構造でサブユニット化でき、装置の組立性を格段に簡便化できると共に、シールプレート等の連結手段には大きな負荷はかからないので、連結手段を強固なものにする必要はなく、シールプレートを鋼鈑のプレス成形で形成でき、低コスト化と一層の軽量化を図ることができる。さらに、補修時に内方部材と等速自在継手とを分離することができ、補修費用を軽減することができる。
【図面の簡単な説明】
【図１】（ａ）は、本発明に係る駆動車輪用軸受装置の第１の実施形態を示す縦断面図である。
（ｂ）は同上、要部拡大断面図である。
【図２】本発明に係る駆動車輪用軸受装置の第２の実施形態を示す縦断面図である。
【図３】本発明に係る駆動車輪用軸受装置の第３の実施形態を示す縦断面図である。
【図４】本発明に係る駆動車輪用軸受装置の第４の実施形態を示す縦断面図である。
【図５】（ａ）は同上、シールプレートの自然状態を示す側面図である。
（ｂ）は同上、シールプレートの縮径した状態を示す側面図である。
（ｃ）は同上、シールプレートの外し方を示す説明図である。
【図６】本発明に係る駆動車輪用軸受装置の第５の実施形態を示す縦断面図である。
【図７】従来の駆動車輪用軸受装置を示す縦断面図である。
【符号の説明】
１、１’、１”・・・・・・・・・内方部材
２、２’、２”、２９・・・・・・ハブ輪
２ａ、３ａ、２９ａ・・・・・・内側転走面
３、３’・・・・・・・・・・・・内輪
４、４’・・・・・・・・・・・・連結部材
４ａ・・・・・・・・・・・・・鍔部
４ｂ、３９・・・・・・・・・・小径段部
４ｃ、３９ａ・・・・・・・・・結合部
５・・・・・・・・・・・・・・車輪取付フランジ
６・・・・・・・・・・・・・・ハブボルト
７・・・・・・・・・・・・・・円筒部
７ａ・・・・・・・・・・・・・端面
８、８’、８”・・・・・・・・・複列の転がり軸受
９・・・・・・・・・・・・・・転動体
１０・・・・・・・・・・・・・外方部材
１０ａ・・・・・・・・・・・・外側転走面
１０ｂ・・・・・・・・・・・・車体取付フランジ
１１・・・・・・・・・・・・・保持器
１２、１３・・・・・・・・・・シール
１４、４１・・・・・・・・・・凹凸部
１５・・・・・・・・・・・・・雄セレーション
１６・・・・・・・・・・・・・スリンガ
１６ａ・・・・・・・・・・・・リップ
１７・・・・・・・・・・・・・シール部材
１７ａ・・・・・・・・・・・・サイドリップ
１７ｂ・・・・・・・・・・・・ラジアルリップ
１８、１８’、３０、３４・・・・シールプレート
１８ａ、３１・・・・・・・・・大径部
１８ｂ、１８ｂ’、３２、３５・・小径部
１９・・・・・・・・・・・・・固定ボルト
１９ａ、３３ａ・・・・・・・・ワッシャ
２０・・・・・・・・・・・・・等速自在継手
２１・・・・・・・・・・・・・外側継手部材
２１ａ、２２ａ・・・・・・・・トラック溝
２２・・・・・・・・・・・・・継手内輪
２３・・・・・・・・・・・・・ケージ
２４・・・・・・・・・・・・・トルク伝達ボール
２５・・・・・・・・・・・・・マウス部
２６・・・・・・・・・・・・・肩部
２７・・・・・・・・・・・・・雌セレーション
２８・・・・・・・・・・・・・開口部
３２ａ・・・・・・・・・・・・ねじ部
３３・・・・・・・・・・・・・固定ナット
３３ｂ、３８・・・・・・・・・キャップ
３６・・・・・・・・・・・・・係止部
３６ａ・・・・・・・・・・・・スリット
３６ｂ・・・・・・・・・・・・爪部
３６ｃ・・・・・・・・・・・・先端部
３７・・・・・・・・・・・・・係止溝
５１・・・・・・・・・・・・・ハブ輪
５１ａ、５９ａ・・・・・・・・内側転走面
５１ｂ・・・・・・・・・・・・小径段部
５２・・・・・・・・・・・・・等速自在継手
５３・・・・・・・・・・・・・複列の転がり軸受
５４・・・・・・・・・・・・・車輪取付フランジ
５５・・・・・・・・・・・・・外側継手部材
５６・・・・・・・・・・・・・ボルト
５７・・・・・・・・・・・・・底部材
５８・・・・・・・・・・・・・肩部
５９・・・・・・・・・・・・・内輪
６０・・・・・・・・・・・・・外方部材
６０ａ・・・・・・・・・・・・外側転走面
６１・・・・・・・・・・・・・転動体
６２・・・・・・・・・・・・・雄セレーション
６３・・・・・・・・・・・・・継手内輪
６４・・・・・・・・・・・・・トルク伝達ボール
６５・・・・・・・・・・・・・ケージ
６６・・・・・・・・・・・・・マウス部
６７・・・・・・・・・・・・・開口
６８・・・・・・・・・・・・・雌セレーション
Ｚ・・・・・・・・・・・・・・分離治具
Ｚ１・・・・・・・・・・・・・テーパ部[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a drive wheel bearing device for supporting a drive wheel of an automobile or the like, and more particularly to a drive wheel bearing device in which a hub wheel, a constant velocity universal joint, and a double row rolling bearing are unitized. .
[0002]
[Prior art]
In recent years, a wheel bearing device that rotatably supports a wheel with respect to a suspension device of an automobile has been reduced in weight for improving fuel efficiency. In particular, in drive wheel bearing devices for automobiles such as front wheels of FF cars, rear wheels of FR cars, rear wheels of RR cars, or all wheels of 4WD cars, the rigidity for driving stability is further improved. Unitization is progressing rapidly.
[0003]
As such a drive wheel bearing device, for example, one described in JP-A-6-193645 is known. FIG. 7 shows a first example of the conventional structure described in this publication. This bearing device for a drive wheel includes a hub wheel 51, an outer joint member 55 of a constant velocity universal joint 52 disposed on the hub wheel 51, and a double row rolling tightly fastened to the hub wheel 51 via the outer joint member 55. The outer joint member 55 is fitted with a bottom member 57 in the opening 67 on the hub wheel 51 side, and a bolt 56 is screwed to the bottom member 57 so that the hub wheel 51 and the constant velocity universal joint 52 are provided. Are separable.
[0004]
Since the bottom member 57 has a space necessary for assembling the joint inside the outer joint member 55 after being joined to the outer joint member 55, the hub 57 is completely assembled after the constant velocity universal joint 52 is completely assembled. The wheel 51 and the outer joint member 55 can be coupled. Therefore, the assembly work of the apparatus to the vehicle can be simplified, the distance between the center of the constant velocity universal joint 52 and the double row rolling bearing 53 can be shortened, and the weight can be reduced. Furthermore, the moment load applied to the coupling portion can be reduced, and the durability of the apparatus can be improved.
[0005]
The hub wheel 51 has a wheel mounting flange 54 for mounting a wheel (not shown) at one end portion, a cylindrical small-diameter step portion 51b, and a male serration 62 at the other end portion. On the other hand, the double-row rolling bearing 53 is press-fitted into the small-diameter step portion 51b of the hub wheel 51 and has a pair of inner rings 59, 59 having an inner rolling surface 59a on the outer periphery, and the inner rolling surface 59a on the inner periphery. The outer member 60 which integrally formed the double row outer side rolling surfaces 60a and 60a facing 59a, and the double row rolling elements 61 and 61 accommodated between these rolling surfaces 60a and 59a are comprised. . Here, as shown in the lower half of the drawing, one of the inner rolling surfaces 59a, 59a may be an inner rolling surface 51a formed directly on the outer periphery of the hub wheel 51.
[0006]
The constant velocity universal joint 52 includes an outer joint member 55, a joint inner ring 63, a cage 65, and a torque transmission ball 64. The outer joint member 55 is hollow and has a cup-shaped mouth portion 66 and a shoulder portion 58 that forms the bottom of the mouth portion 66. A female serration 68 that engages with the male serration 62 of the hub wheel 51 is formed on the inner periphery of the shoulder portion 58, and torque from the engine is transmitted to the hub wheel 51 via the outer joint member 55.
[0007]
Here, the double-row rolling bearing 53 is set to a desired internal clearance, the end surface of the inner ring 59 is brought into contact with the shoulder portion 58 of the outer joint member 55 and positioned and fixed, and fitted into the opening 67 of the shoulder portion 58. A load is applied by the connecting means including the bottom member 57 and the bolt 56.
[0008]
[Problems to be solved by the invention]
In this conventional drive wheel bearing device, the load applied to the double row rolling bearing 53 is received by the bottom member 57 and the bolt 56 via the shoulder 58 of the outer joint member 55, so that only the bottom member 57 is provided. In addition, the bolt 56 itself needs to have an equivalent strength, and there is still a restriction on the weight reduction of the device. Furthermore, there is a possibility that the bearing clearance may fluctuate due to deformation of the bottom member 57, elongation of the bolt 56, loosening of the threaded portion, etc., and this has a problem in terms of bearing life.
[0009]
The present invention has been made in view of such circumstances, and even if a large moment load acts on the apparatus, the coupling portion does not loosen, and the rigidity of the apparatus can be improved. An object of the present invention is to provide a bearing device for a drive wheel that can be easily separated from a constant velocity universal joint and can achieve light weight and compactness.
[0010]
[Means for Solving the Problems]
In order to achieve such an object, the invention according to claim 1 of the present invention is a drive wheel bearing device in which an inner member, a double row rolling bearing, and a constant velocity universal joint are unitized. The member has a hub ring having a wheel mounting flange at one end and an inner ring having at least one inner rolling surface of the double row rolling bearing, and is a female formed on the outer joint member of the constant velocity universal joint. In the bearing device for a drive wheel, in which a rotational torque is transmitted to the hub wheel via a serration, and an axially separable connecting means is provided between the inner member and the outer joint member, the outer joint member A connecting member formed on the outer periphery of the male serration that engages the female serration, and the hub wheel and the double row rolling bearing are unitized in a separable unit, and the connecting means is a sheet formed by steel plate press forming. Has a plate, engage the larger diameter portion of the seal plate to the outer joint member, employing the configuration engaged detachably diameter portion to said inner member.
[0011]
In this way, since the hub wheel and the double row rolling bearing are unitized in a non-separable unit by the connecting member, the so-called self-retained structure that manages and maintains the bearing clearance at the desired negative clearance can be made into a subunit, and the device Assemblability can be remarkably simplified, and there is no heavy load on the connecting means such as the seal plate, so there is no need to make the connecting means strong, and the seal plate can be formed by press forming of steel sheet and is low in cost. And further weight reduction can be achieved. Furthermore, since the large diameter portion of the seal plate is engaged with the outer joint member and the small diameter portion is detachably engaged with the inner member, not only the assembly of the apparatus can be simplified, but also the inner member during repair, etc. The speed universal joint can be separated, and the repair cost can be reduced.
[0012]
Further, as in the invention according to claim 2, the inner member formed a hub ring integrally formed with one inner rolling surface of the double row rolling bearing and the other inner rolling surface. If it has an inner ring and a connecting member that externally fits the hub ring and the inner ring, engages one end of the inner ring with the end surface of the inner ring, and connects the other end to the end of the hub ring, As described above, it is not necessary to adjust the bearing clearance by managing the tightening torque of the fixing bolts, etc., and the assembly of the apparatus can be greatly simplified. Furthermore, since the bearing clearance does not fluctuate, a stable bearing life can be maintained for a long time.
[0013]
According to a third aspect of the present invention, the inner member includes the hub ring, a pair of inner rings forming an inner rolling surface of the double row rolling bearing, and the hub ring and the inner ring. And a connecting member that has one end engaged with the end face of the inner ring and the other end connected to the end of the hub ring, not only the inner ring on the inboard side but also the outboard side. It is possible to use high-carbon chromium steel such as SUJ2 with excellent rolling fatigue life on the inner ring of the steel, and excellent forging workability for the hub wheel, which is not an expensive material considering the rolling fatigue life and is relatively inexpensive. Since the material can be selected, the cost of the apparatus can be reduced.
[0014]
Further, as in the invention described in claim 4, a hardened uneven portion is formed on the inner periphery of the hub wheel, and the connecting portion of the connecting member is fitted into the uneven portion, and the connecting portion is expanded in diameter. When the hub ring and the connecting member are integrally plastically joined into the uneven portion, even if a large moment load acts on the device, the joint does not loosen and the durability is improved. Can do.
[0015]
Further, as in the invention described in claim 5, when the structure in which the connecting member and the hub ring are integrally formed and the end portion of the hub ring is coupled to the end portion of the inner ring is adopted, the number of parts is reduced. The cost can be reduced, and further reduction in weight and size can be achieved.
[0016]
Preferably, as in the invention described in claim 6, a hardened uneven portion is formed on the inner periphery of the inner ring, and the connecting portion of the hub ring is fitted into the uneven portion, and the connecting portion is expanded in diameter. Then, if the inner ring and the hub ring are integrally plastically bonded to the uneven portion, the uneven portion is hardened simultaneously with the hardening treatment of the inner raceway surface of the inner ring and the like. Can do.
[0017]
Further, as in the invention described in claim 7, the connecting means includes the seal plate and a fixing bolt screwed into a small diameter portion of the seal plate, and the head of the fixing bolt is connected to the hub wheel. It is also possible to engage with the end of the seal plate, and as in the invention according to claim 8, the seal plate and a fixing nut screwed into the small diameter portion of the seal plate are provided. A fixing nut may be engaged with the end of the hub wheel.
[0018]
According to a ninth aspect of the present invention, the small diameter portion of the seal plate has a plurality of claw portions, and the claw portions are elastically formed in an annular locking groove formed on the inner periphery of the inner member. The inner member and the outer joint member can be attached and detached with a single touch, the number of parts can be reduced and the cost can be reduced, and the assembly of the apparatus can be simplified. .
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Fig.1 (a) is a longitudinal cross-sectional view which shows 1st Embodiment of the bearing apparatus for drive wheels which concerns on this invention.
[0020]
This bearing device for a drive wheel is constituted by unitizing an inner member 1, a double row rolling bearing 8, and a constant velocity universal joint 20. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outboard side (left side in the drawing), and the side closer to the center is referred to as the inboard side (right side in the drawing).
[0021]
The inner member 1 includes a hub ring 2, another inner ring 3 disposed in abutment with the hub ring 2, and a connecting member 4 that connects the hub ring 2 and the inner ring 3. A hub mounting flange 5 for mounting a wheel (not shown) is provided at an end portion on the outboard side of the hub wheel 2. The wheel mounting flange 5 includes a hub bolt 6 for fastening the wheel at a circumferentially equidistant position. Have been planted. Further, on the outer periphery of the hub wheel 2, one inner rolling surface 2a of a double row rolling bearing 8 to be described later is formed, and a cylindrical portion 7 extending in the axial direction is integrally formed following the inner rolling surface 2a. ing. The other inner rolling surface 3a of the double row rolling bearing 8 is formed on the outer periphery of the inner ring 3 that abuts the end surface 7a of the cylindrical portion 7.
[0022]
On the other hand, the outer member 10 is integrally formed with double row outer rolling surfaces 10a, 10a facing the inner rolling surfaces 2a, 3a on the inner periphery, and a vehicle body mounting flange 10b for mounting to the vehicle body on the outer periphery. Is integrated. The double row rolling bearing 8 mainly includes the outer member 10, the inner member 1, and the double row rolling elements 9, 9 accommodated between the outer member 10 and the inner member 1. . The double-row rolling elements 9 and 9 are held by a snap-on type retainer 11 formed by injection molding of synthetic resin so as to be freely rollable. At the end of the double-row rolling bearing 8, rainwater from the outside is provided. Seals 12 and 13 are installed to prevent the intrusion of dust and the outflow of lubricating grease filled in the bearing. The double row rolling bearing 8 has a negative internal clearance for improving rolling fatigue life and increasing rigidity. Here, although the double row angular contact ball bearing which used the rolling elements 9 and 9 as a ball | bowl was illustrated, it may be a double row tapered roller bearing which uses a tapered roller for not only this but a rolling element.
[0023]
Concave and convex portions 14 are formed on the inner peripheral surface of the end portion of the hub wheel 2, and a hardened layer is formed in a surface hardness range of 58 to 64 HRC by heat treatment. As the heat treatment, quenching by high-frequency induction heating that can adjust the effective hardened layer depth relatively easily is suitable. The concavo-convex portion 14 is formed in an iris knurl shape in which a plurality of rows of grooves are crossed. Moreover, the convex part of the uneven | corrugated | grooved part 14 is formed in tip shape, such as a quadrangular pyramid, in order to ensure biting property.
[0024]
The connecting member 4 has a flange 4a that contacts and fixes the end face of the inner ring 3, a small-diameter step 4b that extends in the axial direction from the flange 4a, and a coupling portion 4c at the tip of the small-diameter step 4b. ing. Further, a male relation (or spline) 15 is formed on the outer periphery of the flange portion 4a. In the connecting member 4, the serration 15 and at least the flange portion 4 a that contacts the inner ring 3 are formed with a hardened layer with a surface hardness of 58 to 64 HRC by heat treatment to improve wear resistance and torsional strength. I am letting. Then, the coupling portion 4c is fitted into the concavo-convex portion 14 formed on the inner periphery of the hub wheel 2, and the concavo-convex portion 14 is expanded by an appropriate means such as inserting / withdrawing a mandrel from / into the inner diameter of the coupling portion 4c. To bite into. Therefore, it is preferable that the joint portion 4c is an unquenched portion having a material hardness of 28HRC or less after forging, and is set to have a hardness difference of 30HRC or more with respect to the surface hardness of 58 to 64HRC of the uneven portion 14. As a result, the coupling portion 4c can easily and deeply bite into the concavo-convex portion 14, and the hub wheel 2 and the connecting member 4 can be firmly plastic-bonded without the tip of the concavo-convex portion 14 being crushed.
[0025]
Here, the plastic coupling by expanding and caulking the hub wheel 2 and the connecting member 4 is illustrated. However, the present invention is not limited to this, and for example, the end of the hub wheel 2 is plastically deformed radially outward. It may be a so-called end face caulking structure that is caulked and plastically bonded. Further, the end portions of the hub wheel 2 and the connecting member 4 may be integrally coupled by electron beam welding or the like.
[0026]
The hub wheel 2 described above is formed of medium carbon steel containing carbon of 0.40 to 0.80 wt%, such as S53C, and the seal land portion where the lip of the seal 12 comes into sliding contact, the inner rolling surface 2a, and the cylindrical portion 7 are formed. A hardened layer is formed in the range of 58 to 64 HRC by heat treatment over the end face 7a to improve wear resistance and fatigue life. Further, the inner ring 3 hardens high carbon chrome steel such as SUJ2 by quenching to improve wear resistance and fatigue life.
[0027]
The constant velocity universal joint 20 includes an outer joint member 21, a joint inner ring 22 (not shown), a cage 23, and a torque transmission ball 24. The outer joint member 21 has a cup-shaped mouth portion 25 and a hollow shoulder portion 26 extending from the mouth portion 25 in the axial direction. A curved track groove 21 a extending in the axial direction is formed on the inner periphery of the mouse portion 25, and the curved track groove 22 a is formed on the outer periphery of the joint inner ring 22 so as to face the track groove 21 a. The centers of curvature of the track grooves 21a and 22a are offset from each other by an equal distance in the axial direction with respect to the joint center. Therefore, the torque transmission ball 24 accommodated between the track grooves 21a and 22a is always held on a bisector of the operating angle at any operating angle to ensure constant velocity.
[0028]
A female serration (or spline) 27 that meshes with the male serration 15 described above is formed on the inner periphery of the shoulder portion 26 of the outer joint member 21, and the torque from the engine is connected to the connecting member 4 through the outer joint member 21. And transmitted to the hub wheel 2. Here, since the female serration 27 is formed to have a larger diameter than the inner diameter of the inner ring 3 by the height of the flange portion 4a, the number of teeth can be increased. Therefore, the width of the female serration 27 can be shortened without reducing the allowable transmission torque, the distance between the center of the constant velocity universal joint 20 and the double row rolling bearing 8 can be shortened, and weight reduction can be achieved. Furthermore, the moment load applied to the coupling portion can be reduced, and the durability of the apparatus can be improved. Here, the male serration 15 of the connecting member 4 is not hardened, is formed to be slightly inclined with respect to the axis, is elastically deformed by meshing with the female serration 27, and wear resistance of the tooth surface by circumferential preload. You may make it suppress improvement and the play of a serration part.
[0029]
1B, the lip 16a of the seal 13 on the inboard side is slidably contacted with the end surface of the shoulder portion 26, and rainwater is brought into contact with the contact portion between the shoulder portion 26 and the inner ring 3. As shown in FIG. Prevents dust from entering the serrations and rusting. The seal 13 includes a slinger 16 having an L-shaped cross section that is fitted on the inner ring 3 and a seal member 17 that is disposed opposite to the slinger 16 and also has an L-shaped cross section. A side lip 17a and a radial lip 17b slidably in contact with the inner peripheral surface of 16 are welded by vulcanization adhesion or the like. The lip 16 a is inclined radially outward toward the tip and is integrally welded to the outer peripheral surface of the slinger 16.
[0030]
The outer joint member 21 is formed of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the track groove 21a, the shoulder portion 26, and the serration 27 are in a range of hardness 58 to 64HRC by induction hardening. A hardened surface layer is formed to improve wear resistance and fatigue life. In addition, the outer joint member 21 can be formed of case-hardened steel such as SCr430, and a hardened layer by carburizing and quenching can be formed on the entire surface.
[0031]
Reference numeral 18 denotes a seal plate, and a steel plate is formed into a hat shape by press molding. The large-diameter portion 18a of the seal plate 18 is fitted to the outboard side opening 28 of the outer joint member 21 so as to face the end surface of the connecting member 4, so that rainwater or dust enters from the outside, and the constant velocity universal joint 20 The inner grease 1 and the outer joint member 21 are coupled together while preventing the lubricating grease filled therein from flowing out.
[0032]
The seal plate 18 has a large-diameter portion 18a and a small-diameter portion 18b integrally formed by welding, the small-diameter portion 18b is fitted to the inner diameter of the connecting member 4, and a fixing bolt 19 is screwed into a screw portion formed in the center portion. The head of the fixing bolt 19 is engaged with the end face of the hub wheel 2 via the washer 19a, so that the inner member 1 and the outer joint member 21 are detachably connected. Here, the inner ring 3 in the inner member 1 is joined in the axial direction by the flange portion 4a of the connecting member 4, and the connecting portion 4c of the connecting member 4 is bitten into the uneven portion 14 of the hub wheel 2 and is plastically joined. A so-called self-retained structure that manages and maintains the bearing clearance at a desired negative clearance can be used as a subunit. Therefore, the bending moment load applied to the double row rolling bearing 8 is received by the cylindrical fitting portion between the cylindrical portion 7 of the hub wheel 2 and the small diameter step portion 4b of the connecting member 4, and is induced by a thrust load or a radial load. The thrust load to be received is received by the flange 4a. Therefore, since a large load is not applied to the seal plate 18 and the fixing bolt 19, it is not necessary to make the seal plate 18 and the fixing bolt 19 strong and further weight reduction can be achieved. Further, unlike the prior art, it is not necessary to adjust the bearing clearance by managing the tightening torque of the fixing bolt 19, and the assembly of the apparatus can be greatly simplified. Further, here, a locking washer is used for the washer 19a to prevent the fixing bolt 19 from loosening. However, the bearing clearance does not fluctuate even if the fixing bolt 19 is loosened. The period can be maintained.
[0033]
FIG. 2 is a longitudinal sectional view showing a second embodiment of the drive wheel bearing device according to the present invention. The difference from the embodiment illustrated in FIG. 1 is only the configuration of the hub wheel and the seal plate. The same parts and the same parts as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
[0034]
This drive wheel bearing device is constituted by unitizing an inner member 1 ′, a double row rolling bearing 8 ′, and a constant velocity universal joint 20. The inner member 1 ′ includes a hub wheel 2 ′, inner rings 3, 29, and a connecting member 4. The hub wheel 2 ′ has a wheel mounting flange 5 for mounting a wheel (not shown). Further, separate inner rings 3 and 29 are press-fitted into the small-diameter step portion 4b of the connecting member 4, and the inner rings 3 and 29 are sandwiched and fixed in the axial direction by the hub ring 2 'and the flange portion 4a. Further, the coupling portion 4c of the connecting member 4 is fitted to the concavo-convex portion 14 formed on the inner periphery of the hub wheel 2 ', the inner diameter of the coupling portion 4c is expanded, and the concavo-convex portion 14 is bitten and plastically coupled, The hub wheel 2 'and the connecting member 4 are integrally coupled. The double row rolling bearing 8 'includes an outer member 10, a pair of inner rings 3, 29, and double row rolling elements 9, 9 accommodated between the respective rolling surfaces 10a, 29a and 10a, 3a. . Here, the configuration in which the inner ring 29 on the outboard side is formed wider than the inner ring 3 on the inboard side and the bending moment load is improved is exemplified. However, the configuration is not limited thereto, and the inner ring 29 includes a pair of inner rings of the same width. You may do it.
[0035]
In the second embodiment, not only the inner ring 3 on the inboard side but also the high-carbon chrome steel such as SUJ2 having excellent rolling fatigue life can be used for the inner ring 29 on the outboard side, and the hub ring 2 ′. In addition, since it is possible to select a relatively inexpensive material instead of an expensive material that is excellent in forging workability and takes the rolling fatigue life into consideration, the cost of the apparatus can be reduced.
[0036]
The seal plate 18 'is formed by pressing a steel plate with the large diameter portion 18a and the small diameter portion 18b' integrated. When the fixing bolt 19 is screwed into the threaded portion formed in the small diameter portion 18b ′, a locking portion (not shown) is provided on the outer periphery of the cylindrical small diameter portion 18b ′ in order to prevent the seal plate 18 ′ from rotating. May be formed and locked to the inner diameter of the connecting member 4.
[0037]
FIG. 3 is a longitudinal sectional view showing a third embodiment of the drive wheel bearing device according to the present invention. Note that the difference from the first embodiment described above is only the coupling member including the seal plate, and other identical parts and parts are denoted by the same reference numerals, and detailed description thereof is omitted.
[0038]
Reference numeral 30 denotes a seal plate fitted to the outboard side opening 28 of the outer joint member 21, and a steel plate is formed into a hat shape by press molding. The large-diameter portion 31 of the seal plate 30 is fitted to the outboard side opening 28 of the outer joint member 21 so as to face the end surface of the connecting member 4, and rainwater and dust enter from the outside, and the constant velocity universal joint 20. It prevents the lubricating grease filled inside from flowing out. The large-diameter portion 31 and the cylindrical small-diameter portion 32 having a threaded portion 32a at the tip are welded and formed integrally. A fixing nut 33 is screwed into the threaded portion 32a, and the inner member 1 and the outer joint member 21 are joined by engaging with the hub wheel 2 via the washer 33a. By adopting such a structure, it is possible to improve the assembly of the device and further reduce the weight. Reference numeral 33b denotes a cap attached to the fixing nut 33 to prevent rainwater and dust from entering the hollow fitting portion 32 from the outside and rusting.
[0039]
FIG. 4 is a longitudinal sectional view showing a fourth embodiment of the drive wheel bearing device according to the present invention. The difference from the first embodiment described above is only the coupling member including the seal plate, and the same reference numerals are assigned to the same parts and the same parts, and detailed description thereof is omitted.
[0040]
34 is a seal plate, and a steel plate is formed into a hat shape by press molding. The large-diameter portion 31 of the seal plate 34 abuts on the end surface of the connecting member 4 and fits into the outboard side opening 28 of the outer joint member 21, so that rainwater and dust can enter from the outside, and the constant velocity universal joint 20. It prevents the lubricating grease filled inside from flowing out. The large-diameter portion 31 and a cylindrical small-diameter portion 35 having a locking portion 36 at the tip are welded and formed integrally. The locking portion 36 has a plurality of slits 36a extending in the axial direction in the small diameter portion 35, and the claw portions 36b between the slits 36a, 36a are bulged outward in the radial direction. On the other hand, an annular locking groove 37 is formed on the inner periphery of the connecting member 4 ′, and the claw portion 36 b is elastically deformed and attached to couple the inner member 1 and the outer joint member 21. By adopting such a structure, it is possible to further improve the assembly of the apparatus and further reduce the weight. Reference numeral 38 denotes a cap attached to the opening of the hub wheel 2 to prevent rainwater and dust from entering the inner member 1 from the outside and rusting.
[0041]
Next, a method of detaching the seal plate 34 from the inner diameter of the connecting member 4 ′ will be described with reference to FIG. (A) shows the latching | locking part 36 of the seal plate 34, and the nail | claw part 36b between slit 36a, 36a bulges from the outer diameter of the cylindrical small diameter part 35 in a natural state, and is formed in the large diameter. . When the seal plate 34 is inserted from the opening on the inboard side of the connecting member 4 ′, the claw portion 36b is elastically deformed as shown in FIG. Decreases in diameter. Further, when the seal plate 34 is inserted to the position of the locking groove 37 of the connecting member 4 ′, the claw portion 36 b is restored and can be locked to the locking groove 37 with one touch. Since the locking groove 37 is formed in a saw blade shape, the seal plate 34 does not come off due to vibration or the like, and the inner member 1 and the outer joint member 21 can be coupled stably.
[0042]
On the other hand, when removing the seal plate 34, as shown in (c), the separating jig Z is inserted into the inner diameter of the connecting member 4 'in the direction of the arrow, and the concave taper portion Z1 formed at the tip is engaged. The distal end portion 36 c of the stop portion 36 is pressed, the slit 36 a is narrowed, and the claw portion 36 b is reduced in diameter to be removed from the locking groove 37.
[0043]
In the fourth embodiment, the inner member 1 and the outer joint member 21 can be coupled with only the seal plate 34 with one touch, and the assembly of the apparatus can be greatly simplified. Further, since the fixing bolt 19 and the fixing nut 33 described above are unnecessary, further cost reduction and weight reduction can be achieved.
[0044]
FIG. 6 is a longitudinal sectional view showing a fifth embodiment of the drive wheel bearing device according to the present invention. Note that the difference from the first embodiment described above is only the inward member, the same reference numerals are assigned to the same parts and parts, and the detailed description thereof is omitted.
[0045]
This drive wheel bearing device is constituted by unitizing an inward member 1 ″, a double row rolling bearing 8 ″, and a constant velocity universal joint 20. The inner member 1 "is composed of a hub wheel 2" and an inner ring 3 ', and the hub wheel 2 "has a wheel mounting flange 5 for mounting a wheel (not shown). The hub wheel 2" The inner peripheral surface 2a of the double-row rolling bearing 8 ", the cylindrical small-diameter step portion 39 extending in the axial direction from the inner rolling surface 2a, and the coupling portion 39a at the tip are integrally formed on the outer periphery of Forming.
[0046]
The inner ring 3 ′ is press-fitted into the small-diameter step portion 39 of the hub wheel 2 ″. The male serration 15 is provided on the outer periphery of the connecting portion 40 extending to the end of the inner ring 3 ′, and the uneven portion 41 is provided on the inner periphery. The inner ring 3 'is made of a high carbon steel such as SUJ2, and is hardened to a range of 58 to 64 HRC by sub-firing.The uneven part 41 is an iris that intersects multiple rows of grooves. It is formed in a knurled shape, and is formed in a pointed shape such as a quadrangular pyramid in order to ensure bite.
[0047]
The connecting portion 39a of the hub wheel 2 "is an unquenched portion with a material hardness of 28HRC or less after forging, and the hardness difference between the surface hardness 58 to 64HRC of the uneven portion 41 formed on the inner periphery of the inner ring 3 'is 30HRC or more. In this way, the connecting portion 39a can easily and deeply bite into the concavo-convex portion 41, and the hub wheel 2 "and the inner ring 3 'can be plastically joined firmly without the tip of the concavo-convex portion 41 being crushed. it can.
[0048]
The hub wheel 2 ″ is made of medium carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C, leaving the coupling part 39a, and the seal land part where the lip of the seal 12 is in sliding contact, and the inner rolling. A hardened layer having a surface hardness of 58 to 64 HRC is formed by heat treatment over the surface 2a and the small-diameter stepped portion 39 to improve wear resistance and fatigue life.
[0049]
In the fourth embodiment, unlike the foregoing, the small-diameter step portion 39 of the hub wheel 2 ″ is extended and directly plastically coupled to the inner ring 3 ′, so that the hub wheel 2 ″ and the inner ring 3 ′ are integrally coupled. Therefore, the connecting members 4 and 4 ′ in the other embodiments described above are not necessary. Therefore, further reduction in weight and size can be achieved.
[0050]
The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.
[0051]
【The invention's effect】
As described above in detail, the drive wheel bearing device according to the present invention is a drive wheel bearing device in which an inner member, a double row rolling bearing, and a constant velocity universal joint are unitized, and the inner member Is a female serration formed on the outer joint member of the constant velocity universal joint, having a hub wheel having a wheel mounting flange at one end and an inner ring having at least one inner rolling surface of the double row rolling bearing. In the drive wheel bearing device in which the rotational torque is transmitted to the hub wheel via the inner wheel and the connecting member that can be separated in the axial direction is provided between the inner member and the outer joint member. A connecting member in which a male serration engaging with a female serration is formed on the outer periphery, and the hub wheel and the double row rolling bearing are unitized in a non-separable unit, and the connecting means is formed by steel plate press molding. Since the seal plate has a structure in which the large diameter portion of the seal plate is engaged with the outer joint member and the small diameter portion is detachably engaged with the inner member, the bearing clearance is set to a desired negative clearance. The so-called self-retained structure that can be managed and maintained can be sub-united, and the assembly of the device can be greatly simplified, and the connecting means such as the seal plate is not subjected to a heavy load, so it is necessary to strengthen the connecting means. In other words, the seal plate can be formed by press forming of a steel plate, so that the cost and the weight can be further reduced. Furthermore, the inner member and the constant velocity universal joint can be separated at the time of repair, and the repair cost can be reduced.
[Brief description of the drawings]
FIG. 1A is a longitudinal sectional view showing a first embodiment of a drive wheel bearing device according to the present invention.
(B) is the principal part expanded sectional view same as the above.
FIG. 2 is a longitudinal sectional view showing a second embodiment of the drive wheel bearing device according to the present invention.
FIG. 3 is a longitudinal sectional view showing a third embodiment of a drive wheel bearing device according to the present invention.
FIG. 4 is a longitudinal sectional view showing a fourth embodiment of a drive wheel bearing device according to the present invention.
FIG. 5A is a side view showing the natural state of the seal plate.
(B) is a side view which shows the state which diameter-reduced the seal plate same as the above.
(C) is explanatory drawing which shows how to remove a seal plate same as the above.
FIG. 6 is a longitudinal sectional view showing a fifth embodiment of the bearing device for a drive wheel according to the present invention.
FIG. 7 is a longitudinal sectional view showing a conventional drive wheel bearing device.
[Explanation of symbols]
1, 1 ', 1 "... inward member
2, 2 ', 2 ", 29 ... ・ Hub wheel
2a, 3a, 29a ... Inside rolling surface
3, 3 '・・・・・・・・・・・ Inner ring
4, 4 '... Connection member
4a ... Tsubaki
4b, 39 ... Small diameter step
4c, 39a...
5 .... Wheel mounting flange
6 ..... hub bolt
7 ・・・・・・・・・・・ Cylinder part
7a ・・・・・・・・ End face
8, 8 ', 8 ".... Double row rolling bearings
9 ..... rolling element
10 ... Outer member
10a ............ Outer rolling surface
10b ..... Body mounting flange
11 ... Cage
12, 13 ... Seal
14, 41 ... concavo-convex part
15 ... male serration
16 ... Slinger
16a ... Lip
17 ... Sealing member
17a ... side lip
17b ... Radial lip
18, 18 ′, 30, 34... Seal plate
18a, 31... Large diameter part
18b, 18b ', 32, 35 .... Small diameter part
19: Fixing bolt
19a, 33a ... Washer
20 ... Constant velocity universal joint
21 ... Outer joint member
21a, 22a ... Track groove
22 ・・・・・・・・・・・・・ Fitting inner ring
23 ... Cage
24 ... Torque transmission ball
25 ... Mouse part
26 ............ Shoulder
27 ... Female Serration
28 ... Opening
32a ..... Screw part
33 ... Fixing nut
33b, 38 ......... Cap
36 ......... Locking part
36a ... slit
36b ..... nail part
36c ・・・・・・・・・・・ Tip
37 ......... Locking groove
51 ............ Hub wheel
51a, 59a ... ・・・・・ Inner rolling surface
51b ・・・・・・・・・・・ Small diameter step
52 ..... Constant velocity universal joint
53 ... Double row rolling bearing
54 ..... Wheel mounting flange
55 ..... Outer joint member
56 ......... Bolt
57 ..... Bottom member
58 ... Shoulder
59 ・・・・・・・・・・・・・ Inner ring
60 ..... External member
60a ............ Outer rolling surface
61 .......... rolling element
62 ... male serration
63 .......... Fitting inner ring
64 ... Torque transmission ball
65 ・・・・・・・・・・・・・ Cage
66 ..... mouse part
67 ............ Opening
68 ... Female serration
Z ......... Separation jig
Z1 ・・・・・・・・ Tapered part

Claims

A bearing device for a drive wheel in which an inner member, a double row rolling bearing and a constant velocity universal joint are unitized, wherein the inner member includes a hub wheel having a wheel mounting flange at one end, and the double row An inner ring having at least one inner rolling surface of a rolling bearing, and transmitting rotational torque to the hub ring via a female serration formed on an outer joint member of the constant velocity universal joint, and the inner member In the drive wheel bearing device provided with a connecting means separable in the axial direction between the outer joint member and
A connecting member formed on the outer periphery of a male serration that engages with the female serration of the outer joint member. The hub wheel and the double row rolling bearing are unitized inseparably, and the connecting means is formed by steel plate press molding. A drive wheel bearing device comprising a formed seal plate, a large-diameter portion of the seal plate engaged with the outer joint member, and a small-diameter portion detachably engaged with the inner member.

The inner member is a hub ring integrally formed with one inner rolling surface of the double row rolling bearing, an inner ring formed with the other inner rolling surface, and the hub ring and the inner ring are externally fitted, 2. The drive wheel bearing device according to claim 1, further comprising a connecting member that engages one end portion with the end face of the inner ring and has the other end portion coupled to the end portion of the hub ring.

The inner member includes the hub ring, a pair of inner rings forming an inner rolling surface of the double row rolling bearing, and the hub ring and the inner ring are externally fitted, and one end portion is engaged with the end surface of the inner ring. The drive wheel bearing device according to claim 1, further comprising a connecting member having the other end coupled to the end of the hub wheel.

A hardened uneven portion is formed on the inner periphery of the hub wheel, and the connecting portion of the connecting member is fitted into the uneven portion, and the diameter of the connecting portion is expanded to bite into the uneven portion. The bearing device for a drive wheel according to any one of claims 1 to 3, wherein the connecting member is integrally plastically coupled.

The drive wheel bearing device according to claim 1, wherein the connecting member and the hub wheel are integrally formed, and an end portion of the hub wheel is coupled to an end portion of the inner ring.

A hardened uneven portion is formed on the inner circumference of the inner ring, and a coupling portion of the hub ring is fitted into the concave and convex portion, and the diameter of the connecting portion is expanded to bite into the concave and convex portion. The bearing device for a drive wheel according to claim 5, wherein the wheel and the wheel are integrally plastically coupled.

The connection means includes the seal plate and a fixing bolt that is screwed into a small diameter portion of the seal plate, and a head portion of the fixing bolt is engaged with an end portion of the hub wheel. A drive wheel bearing device according to claim 1.

The said connection means has the said sealing plate and the fixing nut screwed together in the small diameter part of this sealing plate, and this fixing nut was engaged with the edge part of the said hub ring. Drive wheel bearing device.

The small-diameter portion of the seal plate has a plurality of claw portions, and the claw portions are elastically engaged with an annular locking groove formed on the inner periphery of the inner member. Drive wheel bearing device.