JP3709939B2

JP3709939B2 - Synthetic resin bearing

Info

Publication number: JP3709939B2
Application number: JP24522595A
Authority: JP
Inventors: 鉄也相田
Original assignee: Oiles Corp
Current assignee: Oiles Corp
Priority date: 1995-08-31
Filing date: 1995-08-31
Publication date: 2005-10-26
Anticipated expiration: 2015-08-31
Also published as: JPH0972339A

Description

【０００１】
【発明の属する技術分野】
本発明は合成樹脂軸受、特に四輪自動車におけるストラット型サスペンション（マクファーソン式）に組込まれて好適な合成樹脂軸受に関するものである。
【０００２】
【従来の技術】
一般にストラット型サスペンションは主として四輪自動車の前輪に用いられ、主軸と一体になった外筒の中に油圧式ショックアブソーバを内蔵したストラットアッセンブリにコイルバネを組合せた構造をもっている。かかるサスペンションには、▲１▼ストラットの軸線に対してコイルバネの軸線を積極的にオフセットさせ、該ストラットに内蔵されたショックアブソーバのピストンロッドの摺動を円滑に行わせる構造と、▲２▼ストラットの軸線に対してコイルバネの軸線を同一軸線上に配置させる構造のものとがある。いずれの構造においても、ステアリング操作によりストラットアッセンブリがコイルバネとともに回転するさい、当該回転を円滑に許容するべく車体の取付部材とコイルバネの上部バネ座シートとの間に軸受が配置されている。
【０００３】
そして、この軸受には車体荷重（スラスト荷重）を支持すると同時に前記サスペンション構造に起因するラジアル荷重、すなわち前者の構造においてはコイルバネの軸線がストラットの軸線に対してオフセットされているため、静止状態においてもコイルバネのストラット軸線方向への復元力によって生じるラジアル荷重を、また後者の構造においてはストラットの軸線とコイルバネの軸線とを同一軸線上に配置するという製作上の困難性に起因するミスアライメントによって生じるラジアル荷重を円滑に許容する性能が要求される。しかして、上述した性能を満足するべく従来より、当該軸受にはボールを使用したころがり軸受あるいは合成樹脂製すべり軸受が使用されている。
【０００４】
しかしながら、ころがり軸受は微小揺動、振動荷重等によりボールに疲労破壊を生じる恐れがあり、円滑なステアリング操作を長期間にわたって維持しがたいという問題がある。また合成樹脂製すべり軸受は上記ころがり軸受に比べて摩擦係数が高くステアリング操作を重くするという問題がある。さらに、いずれの軸受においても軸受摺動面への塵埃等異物の混入を防止するべく装着されたゴム弾性体から成るダストシールの摩擦力が高いことに起因するステアリング操作を重くするという問題、特に合成樹脂すべり軸受においてはステアリング操作を一層重くするという問題がある。
【０００５】
上記従来技術における合成樹脂からなるすべり軸受の問題点を解決するべく、本出願人は、先に、実願昭６１−１３３９３１号（実公平４−５２４８８号）において、ゴム弾性体からなるダストシールを使用することなく摺動面への塵埃等異物の侵入を防止し、ステアリング操作時の操舵力の増大を防止できる合成樹脂スラスト軸受を提案した。
【０００６】
ここで、実願昭６１−１３３９３１号（実公平４−５２４８８号）で提案した技術を図１１に基づいて説明する。図１１に示す合成樹脂スラスト軸受Ａは、合成樹脂下部ケースＢと、合成樹脂上部ケースＣと、円板状の合成樹脂軸受片Ｄとから成り、該合成樹脂下部ケースＢは内面に挿通孔１を有する円筒部２と該円筒部２の外周面に該円筒部の一部２ａを突出させて一体に形成された環状幅広鍔部３と該円筒部の一部突出部と該鍔部上面とで環状凹部４を形成して該鍔部外周縁に突設された環状係合突出部５を備えており、該合成樹脂上部ケースＣは円板状の平面部６と該平面部の中央部に形成された円孔７と該平面部６の外周縁に一体に形成された環状係合垂下部８を備えており、該軸受片Ｄは該下部ケースＢの環状凹部４にその下面を摺接させて配され、該下部ケースＢには上部ケースＣがその環状係合垂下部８を該下部ケースＢの環状係合突出部５に弾性装着させ、該弾性装着部にラビリンス作用による密封部を形成して相対回転可能に組み合わされている。
【０００７】
【発明が解決しようとする課題】
上述した構成の合成樹脂スラスト軸受Ａは、図１２に示されるように、挿通孔１、円孔７にストラットのピストンロッドＲを挿通して、下部ケースＢおよび上部ケースＣをピストンロッドＲの外周面に装着され、下部ケースＢの円筒部２外周面を上部バネ座シートＳの孔Ｓ１に嵌合固定すると共に下部ケースＢの環状幅広鍔部３下面を上部バネ座シートＳの平面部Ｓ２に当接させ、上部ケースＣの円板状平面部６上面を車体取付部材Ｆの下面に当接させて、上部バネ座シートＳと車体取付部材Ｆとの間に配置される。
【０００８】
このように配置された合成樹脂スラスト軸受Ａは、上部バネ座シートＳと車体取付部材Ｆとの相対回転を円滑に許容し、ステアリング操作を円滑に行わせるものである。しかしながら、上部バネ座シートＳと車体取付部材Ｆとの間に配置された合成樹脂スラスト軸受Ａに、前述したラジアル荷重が作用した場合、当該ラジアル荷重は下部ケースＢの円筒部挿通孔１とこれを挿通するピストンロッドＲとの摺接、換言すれば合成樹脂と金属との摺接によって許容されることになるため、摺動抵抗が大きく、円滑に許容し難いという問題がある。
本発明は、前記諸点に鑑みてなされたものであって、スラスト荷重ならびにラジアル荷重を摺動摩擦抵抗の小さい合成樹脂同志の組合せによって円滑に許容することができ、またゴム弾性体から成るダストシールを使用することなく軸受摺動面への塵埃等の侵入を防止できる合成樹脂軸受を得ることを目的とするものである。
【０００９】
【課題を解決するための手段】
本発明によれば上記目的は、合成樹脂製の下部ケースと、この下部ケースに組合わされた合成樹脂製の上部ケースと、上部ケースと下部ケースとの間に形成された合成樹脂製のスラストすべり軸受手段とを具備しており、該下部ケースは内面を挿通孔とした円筒部と該円筒部の端部外周面に延設された環状幅広鍔部と該環状幅広鍔部の上面に該円筒部と環状溝を形成して立設された環状突出部と該環状突出部と該環状幅広鍔部の上面とで環状凹部を形成して該環状幅広鍔部の外周縁に立設された環状係合突出部とを備えており、該上部ケースは円筒部と該円筒部の端部外周面に延設された環状幅広鍔部と該円筒部の他端に径方向内側に延設された環状鍔部と該環状幅広鍔部の外周縁に垂下した環状係合垂下部とを備えており、該上部ケースはその円筒部の内周面と前記下部ケースの円筒部の外周面との間に軸受隙間を保持してラジアル軸受部を形成し、かつ環状鍔部の下面を該下部ケースの円筒部の端面に対面させるとともに環状係合垂下部を前記下部ケースの環状係合突出部に弾性装着させて該下部ケースに組合わされており、スラストすべり軸受手段は下部ケースの環状凹部と該環状凹部に対面する上部ケースの環状幅広鍔部の下面との間の空間に形成されている合成樹脂軸受によって達成される。
【００１０】
また、上記構成において、下部ケースは環状幅広鍔部の上面に、該環状係合突出部と径方向内側に環状溝を形成して立設された外側環状突出部をさらに備えており、該上部ケースは環状幅広鍔部の下面に、環状係合垂下部と径方向内側に環状溝を形成して垂下した環状垂下部をさらに備えており、該上部ケースはその円筒部の内周面と前記下部ケースの円筒部の外周面との間に軸受隙間を保持してラジアル軸受部を形成し、かつ環状鍔部の下面を該下部ケースの円筒部の端面に対面させ、環状垂下部の端部を該下部ケースの外側環状突出部の端部とその径方向に重畳させて該重畳部にラビリンス作用による密封部を形成して係合させるとともに環状係合垂下部を前記下部ケースの環状係合突出部に弾性装着させて該下部ケースに組み合わされている合成樹脂軸受とすることもできる。
【００１１】
さらに、本発明によれば上記目的は、合成樹脂製の下部ケースと、この下部ケースに組合わされた合成樹脂製の上部ケースと、上部ケースと下部ケースとの間に形成された合成樹脂製のスラストすべり軸受手段とを具備しており、該下部ケースは内面を挿通孔とした円筒部と該円筒部の端部外周面に延設された環状幅広鍔部と該円筒部の外周面に拡径環状肩部を介して下方に延設された円筒状壁部と該環状幅広鍔部の上面に該円筒状壁部と環状溝を形成して立設された環状突出部と該環状突出部と該環状幅広鍔部の上面とで環状凹部を形成して該環状幅広鍔部の外周縁に立設された環状係合突出部とを備えており、上部ケースは円筒部と該円筒部の端部外周面に延設された環状幅広鍔部と該円筒部の他端に径方向内側に延設された環状鍔部と該円筒部の内周面に拡径環状肩部を介して下方に延設され、該環状幅広鍔部の下面に垂下する内側環状垂下部と該環状幅広鍔部の外周縁に垂下した環状係合垂下部とを備えており、該上部ケースはその円筒部の内周面と前記下部ケースの円筒部の外周面との間に軸受隙間を保持してラジアル軸受部を形成し、かつ環状鍔部の下面を該下部ケースの円筒部の端面に、拡径環状肩部を該下部ケースの拡径環状肩部にそれぞれ対面させ、内側環状垂下部の端部を該下部ケースの環状突出部の端部とその径方向に重畳させて該重畳部にラビリンス作用による密封部を形成して係合させるとともに環状係合垂下部を該下部ケースの環状係合突出部に弾性装着させて該下部ケースに組み合わされており、スラストすべり軸受手段は下部ケースの環状凹部と該環状凹部に対面する上部ケースの環状幅広鍔部の下面との間の空間に形成されている合成樹脂軸受によっても達成される。
【００１２】
また、上記構成において、下部ケースは環状幅広鍔部の上面に、該環状係合突出部と径方向内側に環状溝を形成して立設された外側環状突出部をさらに備えており、該上部ケースは環状幅広鍔部の下面に、該環状係合垂下部と径方向内側に環状溝を形成して垂下した環状垂下部をさらに備えており、該上部ケースはその円筒部の内周面と前記下部ケースの円筒部の外周面との間に軸受隙間を保持してラジアル軸受部を形成し、かつ環状鍔部の下面を該下部ケースの円筒部の端面に、拡径環状肩部を該下部ケースの拡径環状肩部にそれぞれ対面させ、内側環状垂下部の端部を該下部ケースの環状突出部の端部と、環状垂下部の端部を該下部ケースの外側環状突出部の端部と、それぞれその径方向に重畳させて該重畳部にラビリンス作用による密封部を形成して係合させるとともに環状係合垂下部を前記下部ケースの環状係合突出部に弾性装着させて該下部ケースに組合わされている合成樹脂軸受とすることもできる。
【００１３】
スラストすべり軸受手段は、下部ケースの環状凹部と該環状凹部に対面する上部ケースの環状幅広鍔部の下面との間の空間に配され、環状凹部の底面と環状幅広鍔部の下面に対して摺動自在に配された合成樹脂製の環状スラスト軸受体によって形成されるか、または下部ケースの環状凹部と該環状凹部に対面する上部ケースの環状幅広鍔部の下面との間の空間に配され、環状凹部の底面に対して摺動自在に配された該環状幅広鍔部の下面に一体に形成された環状のスラスト軸受突部によって形成されている。
【００１４】
本発明の合成樹脂軸受における上部および下部ケースを構成する合成樹脂は、耐摩耗性、耐衝撃性、耐クリープ性等の摺動特性および機械的特性に優れていることが好ましく、また上部および下部ケース間に配されるスラストすべり軸受手段を構成する合成樹脂はとくに自己潤滑性を有することが好ましく、例えばポリアセタール樹脂、ポリアミド樹脂、ポリブチレンテレフタレート（ＰＢＴ）等の熱可塑性ポリエステル樹脂、ポリエチレン、ポリプロピレン等のポリオレフィン樹脂等が良好に使用される。
【００１５】
上部および下部ケースには、スラストすべり軸受手段を構成する合成樹脂と同様の合成樹脂が使用されるが、とくにスラストすべり軸受手段に使用される合成樹脂と摺動摩擦特性の良好な組合せであって、しかも比較的剛性の高い合成樹脂であることが望ましい。その望ましい組合せについて例示すると、上部ケースにポリアセタール樹脂を、下部ケースにポリアミド樹脂を、スラストすべり軸受手段にポリオレフィン樹脂を使用する組合せ、スラストすべり軸受手段として上部ケースの環状幅広鍔部下面に一体に形成された環状スラスト軸受部を具備した上部ケースにポリアセタール樹脂を、下部ケースにポリアミド樹脂あるいはＰＢＴを使用する組合せがある。
【００１６】
本発明の合成樹脂軸受は、四輪自動車におけるストラット型サスペンション（マクファーソン式）に組込まれ、車体の取付部材とストラットアッセンブリの上部バネ座シートとの間に配されて使用される。そして、ステアリング操作によりストラットアッセンブリが回動されると、上部ケースに対して下部ケースが回転され、この下部ケースの回転は、上部ケースと下部ケースとの間に形成される合成樹脂製のスラストすべり軸受手段によって円滑に許容され、ステアリング操作も円滑に行われる。合成樹脂軸受にラジアル荷重が作用した場合でも、当該ラジアル荷重は上部ケースの円筒部の内周面と下部ケースの円筒部の外周面との間に軸受隙間を保持して形成されたラジアル軸受部における合成樹脂同志の摺接によって円滑に許容される。
【００１７】
【発明の実施の形態】
つぎに本発明の実施の形態を、図に示す好ましい実施例に基づいてさらに詳細に説明する。本発明はこれら実施例に何ら限定されないのである。
【００１８】
【実施例】
図１において、本例の合成樹脂軸受１０は、合成樹脂製の下部ケース２０と、この下部ケースに組合わされた合成樹脂製の上部ケース３０と、上部ケースと下部ケースとの間に形成された合成樹脂製のスラストすべり軸受手段４０とを具備している。
【００１９】
該下部ケース２０は内面２１を係合孔とした円筒部２２と該円筒部２２の端部外周面に延設された環状幅広鍔部２３と該環状幅広鍔部２３の上面に該円筒部２２と環状溝２４を形成して立設された環状突出部２５と該環状突出部２５と環状幅広鍔部上面とで環状凹部２６を形成して該幅広鍔部２３の外周縁に立設された環状係合突出部２７とを備えている。該環状係合突出部２７はその外周面に、該突出部２７の端部から外方に向けて傾斜するテーパ面部と該テーパ面部と連続し、環状凸角部を形成して該幅広鍔部２３の外周面に連なるテーパ面部とから成る係合部２８を具備している。
【００２０】
該上部ケース３０は円筒部３１と該円筒部３１の端部外周面に延設された環状幅広鍔部３２と該円筒部３１の他端に径方向内側に延設された環状鍔部３３と該幅広鍔部３２の外周縁に垂下した環状係合垂下部３４を備えている。該環状係合垂下部３４はその内周面に、基部から外方に向けて傾斜するテーパ面部と該テーパ面部と連続し、環状凹角部を形成して該垂下部３４の下端に連なるテーパ面部とから成る係合フック部３５を具備している。
【００２１】
該上部ケース３０はその円筒部３１の内周面と前記下部ケース２０の円筒部２２の外周面との間に軸受隙間を保持してラジアル軸受部を形成し、かつ環状鍔部３３の下面を該下部ケース２０の円筒部２２の端面に対面させるとともに環状係合垂下部３４の係合フック部３５を該下部ケース２０の環状係合突出部２７の係合部２８に弾性装着させて該下部ケース２０に組合わされている。このように組合わされた上部および下部ケース３０、２０間には外周側の弾性装着部と内周側の環状鍔部３３の下面と下部ケース２０の円筒部２２の端面との対面部に、外部から軸受摺動面への塵埃等異物の侵入を防止する密封部が形成されている。
【００２２】
スラストすべり軸受手段４０は、下部ケース２０の環状凹部２６と該環状凹部２６に対面する上部ケース３０の環状幅広鍔部３２下面との間の空間に、これら環状凹部２６の底面と環状幅広鍔部３２下面に対して摺動自在に配され、前記下部ケース２０の環状突出部２５の外径より大きい内径を有し、環状係合突出部２７の内径より小さい外径を有する環状スラスト軸受体４１から成る。該軸受体４１の両端面には、その内径側の周縁にリング溝４２が形成されていると共に該リング溝４２から外径側に開口する複数個の放射状溝４３が円周方向に等間隔に、かつ３０度の位相差をもって形成されている。該リング溝４２および放射状溝４３はグリースなどの潤滑剤の溜り部となる。
【００２３】
図３は他の具体例を示すもので、本例の合成樹脂軸受１０は前述の合成樹脂軸受において、下部ケース２０の環状幅広鍔部２３の上面に、該環状係合突出部２７と径方向内側に環状溝２９を形成して立設された外側環状突出部２５ａをさらに備えており、また該上部ケース３０は環状幅広鍔部３２の下面に、該環状係合垂下部３４と径方向内側に環状溝３６を形成して垂下した環状垂下部３７をさらに備えている。そして、該上部ケース３０はその円筒部３１の内周面と該下部ケース２０の円筒部２２の外周面との間に軸受隙間を保持してラジアル軸受部を形成し、かつ環状鍔部３３の下面を該下部ケース２０の円筒部２２の端面に対面させ、環状垂下部３７の端部を該下部ケース２０の外側環状突出部２５ａの端部とその径方向に重畳させて該重畳部にラビリンス作用による密封部を形成して係合させるとともに環状係合垂下部３４の係合フック部３５を下部ケース２０の環状係合突出部２７の係合部２８に弾性装着させて該下部ケース２０に組合わされている。

【００２４】
このように組合わされた上部および下部ケース３０、２０間には、その外周側に弾性装着部と環状垂下部３７の端部と該下部ケース２０の外側環状突出部２５ａの端部との重畳部に形成されたラビリンス作用による密封部が形成され、またその内周側に環状鍔部３３の下面と下部ケース２０の円筒部２２端面との対面部に密封部が形成され、これら密封部により外部から軸受摺動面への塵埃等の侵入を防止している。
【００２５】
このように構成された合成樹脂軸受１０は、図４に示すストラットアッセンブリに組込まれる。すなわち、軸受１０は、下部ケース２０の円筒部内面２１をストラットアッセンブリの上部バネ座シートＳの円筒状突出部Ｓ１の外周面に嵌合させるとともに環状幅広鍔部２３の下面を該上部バネ座シートＳの平面部Ｓ２に着座させ、上部ケース３０の円筒部３１を車体側取付部材Ｆの孔Ｆ１に嵌合させるとともに上部ケース３０の環状幅広鍔部３２上面を該車体側取付部材Ｆの下面に当接させて上部バネ座シートＳと車体側取付部材Ｆとの間に配置される。なお、図４中、符号Ｒはストラットアッセンブリのピストンロッド、符号Ｂはコイルスプリングを示す。
【００２６】
上部バネ座シートＳと車体側取付部材Ｆとの間に配置された合成樹脂軸受１０に、サスペンションの構造に起因するラジアル荷重が作用した場合は、当該ラジアル荷重は上部ケース３０の円筒部３１の内周面と下部ケース２０の円筒部２２の外周面との間に軸受隙間を保持して形成されたラジアル軸受部における合成樹脂同志の摺動によって円滑に許容される。また、車体重量は、下部ケース２０の環状凹部２６と該環状凹部２６に対面する上部ケース３０の環状幅広鍔部３２の下面との間の空間に配され、該環状凹部２６の底面と環状幅広鍔部３２の下面に対して摺動自在に配された合成樹脂製の環状スラスト軸受体４１で形成されたスラストすべり軸受手段４０によって支持されるとともにスラスト荷重は下部ケース２０の環状凹部２６と環状スラスト軸受体４１と上部ケース３０の環状幅広鍔部３２の下面との間の合成樹脂同志の摺動によって円滑に許容される。
【００２７】
図５は他の具体例を示すもので、本例の合成樹脂軸受１０は、前述した図１に示す合成樹脂軸受において、該下部ケース２０は円筒部２２の外周面に拡径環状肩部２２ａを介して下方に延設された円筒状壁部２２ｂをさらに備えており、環状突出部２５は該円筒状壁部２２ｂと環状溝２４を形成して該環状幅広鍔部２３の上面に立設されている。また、上部ケース３０は円筒部３１の内周面に拡径環状肩部３１ａを介して下方に延設され、該環状幅広鍔部３２の下面に垂下する内側環状垂下部３７ａをさらに備えている。そして、該上部ケース３０はその円筒部３１の内周面と該下部ケース２０の円筒部２２の外周面との間に軸受隙間を保持してラジアル軸受部を形成し、かつ環状鍔部３３の下面を該下部ケース２０の円筒部２２の端面に、拡径環状肩部３１ａを該下部ケース２０の拡径環状肩部２２ａにそれぞれ対面させ、内側環状垂下部３７ａの端部を該下部ケース２０の環状突出部２５の端部とその径方向に重畳させて該重畳部にラビリンス作用による密封部を形成して係合させるとともに環状係合垂下部３４の係合フック部３５を該下部ケース２０の環状係合突出部２７の係合部２８に弾性装着させて該下部ケース２０に組合わされている。このように組合わされた上部ケース３０と下部ケース２０との間には外周側の弾性装着部と内周側の環状鍔部３３の下面と下部ケース２０の円筒部２２の端面との対面部及び内側環状垂下部３７ａの端部と該下部ケース２０の環状突出部２５の端部との径方向の重畳部に、外部から軸受摺動面への塵埃等異物の侵入を防止する密封部が形成されている。
【００２８】
図６はさらに他の具体例を示すもので、本例の合成樹脂軸受１０は、上記図５に示す合成樹脂軸受において、下部ケース２０は環状幅広鍔部２３の上面に、該環状係合突出部２７と径方向内側に環状溝２９を形成して立設された外側環状突出部２５ａをさらに備えており、また該上部ケース３０は環状幅広鍔部３２の下面に、該環状係合垂下部３４と径方向内側に環状溝３６を形成して垂下した環状垂下部３７をさらに備えている。そして、該上部ケース３０はその円筒部３１の内周面と該下部ケース２０の円筒部２２の外周面との間に軸受隙間を保持してラジアル軸受部を形成し、かつ環状鍔部３３の下面を該下部ケース２０の円筒部２２の端面に、拡径環状肩部３１ａを該下部ケース２０の拡径環状肩部２２ａにそれぞれ対面させ、内側環状垂下部３７ａの端部を該下部ケース２０の環状突出部２５の端部と、環状垂下部３７の端部を該下部ケース２０の外側環状突出部２５ａの端部と、それぞれその径方向に重畳させて該重畳部にラビリンス作用による密封部を形成して係合させるとともに環状係合垂下部３４の係合フック部３５を下部ケース２０の環状係合突出部２７の係合部２８に弾性装着させて該下部ケース２０に組合わされている。
【００２９】
このように組合わされた上部および下部ケース３０、２０間にはその外周側に弾性装着部と環状垂下部３７の端部と該下部ケース２０の外側環状突出部２５ａの端部との重畳部に形成されたラビリンス作用による密封部が形成され、またその内周側に環状鍔部３３の下面と下部ケース２０の円筒部２２端面との対面部と内側環状垂下部３７ａの端部と該下部ケース２０の環状突出部２５の端部との重畳部にラビリンス作用による密封部が形成され、これらにより外部から軸受摺動面への塵埃等の侵入を防止している。
【００３０】
ところで上述した図１、図３、図５および図６に示した具体例では、下部ケース２０の環状凹部２４と該環状凹部２４に対面する上部ケース３０の環状幅広鍔部３３下面との間の空間に、環状スラスト軸受体４１からなるスラストすべり軸受手段４０を構成したが、これに代えて図７ないし図１０に示すように、スラストすべり軸受手段４０を、上部ケース３０の環状幅広鍔部３２の下面に一体に形成され、下部ケース２０の環状突出部２５の外径より大きい内径を有し、環状係合突出部２７あるいは外側環状突出部２５ａの内径より小さい外径を有する環状のスラスト軸受突部４４から構成してもよい。この図７ないし図１０に示す合成樹脂軸受１０の構成において、スラストすべり軸受手段４０を除く他の構成は前述した図１、図３、図５および図６に示した構成と同様である。
【００３１】
この図７ないし図１０に示す合成樹脂軸受１０においては、スラスト荷重は環状のスラスト軸受突部４４の端面と下部ケース２０の環状凹部２５底面との摺動で許容される。この場合、環状のスラスト軸受突部４４の端面にリング溝と放射状溝が形成されている。
【００３２】
【発明の効果】
本発明の合成樹脂軸受では、サスペンションの構造に起因するラジアル荷重が作用した場合でも、当該ラジアル荷重は上部ケースの円筒部外周面と下部ケースの円筒部内周面との間に軸受隙間を保持して形成されたラジアル軸受部における合成樹脂同志の摺動によって円滑に許容される。
【図面の簡単な説明】
【図１】本発明の合成樹脂軸受の断面図である。
【図２】図１に示す合成樹脂軸受におけるスラストすべり軸受体の平面図である。
【図３】本発明の合成樹脂軸受の更に他の具体例を示す断面図である。
【図４】図３に示す合成樹脂軸受をストラットアッセンブリに組込んだ状態の断面図である。
【図５】本発明の合成樹脂軸受の他の具体例を示す断面図である。
【図６】本発明の合成樹脂軸受の他の具体例を示す断面図である。
【図７】本発明の合成樹脂軸受の他の具体例を示す断面図である。
【図８】本発明の合成樹脂軸受の他の具体例を示す断面図である。
【図９】本発明の合成樹脂軸受の他の具体例を示す断面図である。
【図１０】本発明の合成樹脂軸受の他の具体例を示す断面図である。
【図１１】従来技術の合成樹脂軸受の断面図である。
【図１２】図１１に示す合成樹脂軸受をストラットアッセンブリに組込んだ状態の断面図である。
【符号の説明】
１０合成樹脂軸受
２０下部ケース
２１内面
２２円筒部
２３環状幅広鍔部
２５環状突出部
２６環状凹部
２７環状係合突出部
３０上部ケース
３１円筒部
３２環状幅広鍔部
３３環状鍔部
３４環状係合垂下部
４０スラストすべり軸受手段
４１環状スラスト軸受体[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a synthetic resin bearing, and more particularly to a synthetic resin bearing suitable for being incorporated into a strut suspension (McPherson type) in a four-wheeled vehicle.
[0002]
[Prior art]
Generally, a strut suspension is mainly used for a front wheel of a four-wheeled vehicle, and has a structure in which a coil spring is combined with a strut assembly in which a hydraulic shock absorber is incorporated in an outer cylinder integrated with a main shaft. The suspension includes (1) a structure in which the axis of the coil spring is positively offset with respect to the axis of the strut so that the piston rod of the shock absorber built in the strut can smoothly slide, and (2) the strut There is a structure in which the axis of the coil spring is arranged on the same axis with respect to this axis. In any structure, when the strut assembly is rotated together with the coil spring by the steering operation, a bearing is disposed between the mounting member of the vehicle body and the upper spring seat of the coil spring so as to allow the rotation smoothly.
[0003]
This bearing supports the vehicle body load (thrust load) and at the same time the radial load resulting from the suspension structure, that is, the axis of the coil spring is offset with respect to the axis of the strut in the former structure. The radial load generated by the restoring force of the coil spring in the strut axial direction is caused by misalignment due to the manufacturing difficulty of arranging the strut axis and the coil spring axis on the same axis in the latter structure. Performance that smoothly allows radial load is required. In order to satisfy the above-described performance, a rolling bearing using a ball or a synthetic resin sliding bearing is conventionally used as the bearing.
[0004]
However, rolling bearings may cause fatigue damage to the balls due to minute swings, vibration loads, etc., and there is a problem that it is difficult to maintain a smooth steering operation over a long period of time. In addition, the synthetic resin plain bearing has a problem that it has a higher coefficient of friction and makes the steering operation heavier than the above rolling bearing. Furthermore, in any bearing, there is a problem that the steering operation becomes heavy due to the high frictional force of the dust seal made of a rubber elastic body that is installed to prevent foreign matters such as dust from entering the sliding surface of the bearing. The resin sliding bearing has a problem that the steering operation becomes heavier.
[0005]
In order to solve the problems of the plain bearing made of a synthetic resin in the above-described prior art, the present applicant previously disclosed a dust seal made of a rubber elastic body in Japanese Patent Application No. 61-133931 (Japanese Utility Model Publication No. 4-52488). A synthetic resin thrust bearing has been proposed that prevents foreign matter such as dust from entering the sliding surface without using it, and prevents an increase in steering force during steering operation.
[0006]
Here, the technique proposed in Japanese Patent Application No. 61-133931 (Japanese Utility Model Publication No. 4-52488) will be described with reference to FIG. A synthetic resin thrust bearing A shown in FIG. 11 includes a synthetic resin lower case B, a synthetic resin upper case C, and a disc-shaped synthetic resin bearing piece D. The synthetic resin lower case B has an insertion hole 1 on the inner surface. A cylindrical portion 2 having a cylindrical shape, an annular wide flange portion 3 integrally formed by projecting a portion 2a of the cylindrical portion on the outer peripheral surface of the cylindrical portion 2, a partially protruding portion of the cylindrical portion, and an upper surface of the flange portion, The annular recess 4 is formed, and an annular engagement protrusion 5 is provided on the outer periphery of the flange, and the synthetic resin upper case C includes a disk-shaped flat portion 6 and a central portion of the flat portion. And the annular engagement hanging portion 8 formed integrally with the outer peripheral edge of the flat portion 6, and the bearing piece D slides on the lower surface of the annular recess 4 of the lower case B. The lower case B is arranged in contact with the upper case C, and the annular engagement hanging portion 8 is connected to the annular engagement protrusion of the lower case B. The elastic is attached, it is combined to be relatively rotated to form a seal by the labyrinth effect the elastic mounting unit.
[0007]
[Problems to be solved by the invention]
As shown in FIG. 12, the synthetic resin thrust bearing A having the above-described configuration is configured such that the strut piston rod R is inserted into the insertion hole 1 and the circular hole 7, and the lower case B and the upper case C are connected to the outer periphery of the piston rod R. The outer peripheral surface of the cylindrical portion 2 of the lower case B is fitted and fixed in the hole S1 of the upper spring seat S, and the lower surface of the annular wide flange portion 3 of the lower case B is attached to the flat portion S2 of the upper spring seat S. The upper surface of the upper case C is disposed between the upper spring seat S and the vehicle body mounting member F so that the upper surface of the disk-shaped flat portion 6 of the upper case C contacts the lower surface of the vehicle body mounting member F.
[0008]
The synthetic resin thrust bearing A arranged in this manner smoothly allows relative rotation between the upper spring seat S and the vehicle body attachment member F, and smoothly performs the steering operation. However, when the above-described radial load is applied to the synthetic resin thrust bearing A disposed between the upper spring seat S and the vehicle body mounting member F, the radial load is applied to the cylindrical portion insertion hole 1 of the lower case B and this. Since this is allowed by sliding contact with the piston rod R through which it is inserted, in other words, by sliding contact between the synthetic resin and the metal, there is a problem that the sliding resistance is large and it is difficult to allow it smoothly.
The present invention has been made in view of the above-mentioned points, and can smoothly allow a thrust load and a radial load by a combination of synthetic resins having a small sliding friction resistance, and uses a dust seal made of a rubber elastic body. It is an object of the present invention to obtain a synthetic resin bearing that can prevent dust and the like from entering the sliding surface of the bearing.
[0009]
[Means for Solving the Problems]
  According to the present invention, the object is to provide a lower case made of synthetic resin, an upper case made of synthetic resin combined with the lower case,Case andLower caseWithBetweenFormationThe synthetic resin thrust sliding bearing means, and the lower case includes a cylindrical portion having an inner surface as an insertion hole, an annular wide flange portion extending on an outer peripheral surface of the cylindrical portion, and the lower case.RingAn annular projection that is erected by forming the cylindrical portion and an annular groove on the upper surface of the wide flange portion, the annular projection, and the annular projectionRingWide collarofForming an annular recess with the upper surface;RingAnd an annular engagement protrusion portion erected on the outer peripheral edge of the wide flange portion, and the upper case has a cylindrical portion, an annular wide flange portion extended on the outer peripheral surface of the end portion of the cylindrical portion, and the cylindrical portion An annular flange extending radially inward to the other end of theRingAn annular engagement hanging portion that hangs down on the outer peripheral edge of the wide collar, and the upper case isThatCylindrical partofInner peripheral surface and cylindrical portion of the lower caseofBetween the outer peripheral surfaceHolding the bearing gapForming a radial bearing,AndAnnulusofThe lower part is the cylindrical part of the lower caseofAn annular engagement hanging portion is elastically attached to the annular engagement projecting portion of the lower case so as to face the end surface and is combined with the lower case, and the thrust slide bearing means is connected to the annular recess of the lower case.Facing the annular recessAnnular wide collar of upper caseIt is formed in the space between the lower surface ofThis is achieved with a synthetic resin bearing.
[0010]
  Further, in the above configuration, the lower case further includes an outer annular projecting portion erected by forming an annular groove on the upper surface of the annular wide flange portion and an annular groove on the radially inner side, The case further includes an annular engagement hanging portion on the lower surface of the annular wide flange portion and an annular hanging portion formed by hanging an annular groove radially inward,TheThe upper case isThatCylindrical partofInner peripheral surface and cylindrical portion of the lower caseofBetween the outer peripheral surfaceHolding the bearing gapForming a radial bearing,AndAnnulusofThe lower part is the cylindrical part of the lower caseofThe end of the annular hanging part is overlapped with the end of the outer annular projecting part of the lower case in the radial direction.Form a sealing part by labyrinth action on the overlapping partAn annular engagement hanging portion is elastically attached to the annular engagement protrusion of the lower case and combined with the lower case.HaveIt can also be a synthetic resin bearing.
[0011]
  Further, according to the present invention, the object is to provide a lower case made of synthetic resin, an upper case made of synthetic resin combined with the lower case,Case andLower caseWithBetweenFormationA synthetic resin thrust sliding bearing means, and the lower case has a cylindrical portion having an inner surface as an insertion hole, an annular wide flange portion extending from the outer peripheral surface of the end portion of the cylindrical portion, and the cylinder A cylindrical wall portion extending downwardly through an enlarged annular shoulder on the outer peripheral surface of the portion, andRingAn annular protrusion that is erected by forming the cylindrical wall and an annular groove on the upper surface of the wide collar, the annular protrusion, and the annular protrusionRingAn annular recess is formed with the upper surface of the wide collar,RingAn annular engagement protrusion that is erected on the outer peripheral edge of the wide collar, and the upper case has a cylindrical portion, an annular wide collar that extends on the outer peripheral surface of the end of the cylindrical portion, and the cylindrical portion. An annular flange extending radially inwardly at the other end and an inner circumferential surface of the cylindrical portion are extended downward via an expanded annular shoulder,RingAn inner annular hanging portion hanging from the lower surface of the wide collar portion, and theRingAn annular engagement hanging portion that hangs down on the outer peripheral edge of the wide collar, and the upper case isThatCylindrical partofInner peripheral surface and cylindrical portion of the lower caseofBetween the outer peripheral surfaceHolding the bearing gapForming a radial bearing,AndAnnulusofThe lower part is the cylindrical part of the lower caseofThe diameter-enlarged annular shoulder portion faces the diameter-enlarged annular shoulder portion of the lower case on the end surface, and the end portion of the inner annular hanging portion overlaps with the end portion of the annular projecting portion of the lower case in the radial direction.Form a sealing part by labyrinth action on the overlapping partEngage and make the annular engagement hanging part elastically attach to the annular engagement projection of the lower caseTheThe thrust slide bearing means is combined with the lower case and the annular recess of the lower case.Facing the annular recessAnnular wide collar of upper caseIt is formed in the space between the lower surface ofThis is also achieved by a synthetic resin bearing.
[0012]
  Further, in the above configuration, the lower case further includes an outer annular projecting portion erected by forming an annular groove on the upper surface of the annular wide flange portion and an annular groove on the radially inner side, The case further includes an annular hanging portion formed on the lower surface of the annular wide flange portion and a ring-shaped hanging portion formed in a radially inner side by forming an annular groove.ThatCylindrical partofInner peripheral surface and cylindrical portion of the lower caseofBetween the outer peripheral surfaceHolding the bearing gapForming a radial bearing,AndAnnulusofThe lower part is the cylindrical part of the lower caseofOn the end face, the enlarged annular shoulder portion faces the enlarged annular shoulder portion of the lower case, and the end portion of the inner annular hanging portion is connected to the end portion of the annular projecting portion of the lower case and the end portion of the annular hanging portion. Overlapping the end of the outer annular protrusion of the lower case in the radial directionForm a sealing part by labyrinth action on the overlapping partAn annular engagement hanging portion is elastically attached to the annular engagement protrusion of the lower case and combined with the lower case.HaveIt can also be a synthetic resin bearing.
[0013]
  The thrust plain bearing means is connected to the annular recess of the lower case.Facing the annular recessAnnular wide collar of upper caseIs formed by an annular thrust bearing body made of a synthetic resin that is disposed in a space between the lower surface of the annular recess and is slidably disposed on the bottom surface of the annular recess and the lower surface of the annular wide flange portion,Or an annular recess in the lower caseFacing the annular recessAnnular wide collar of upper caseIs arranged in a space between the lower surface of the ring and slidable with respect to the bottom surface of the annular recessThe annular wide collarofAnnular thrust bearing formed integrally on the lower surfaceSuddenPartIs formed by.
[0014]
The synthetic resin constituting the upper and lower cases in the synthetic resin bearing of the present invention preferably has excellent sliding and mechanical properties such as wear resistance, impact resistance and creep resistance, and upper and lower portions. The synthetic resin constituting the thrust slide bearing means disposed between the cases is particularly preferably self-lubricating, for example, polyacetal resin, polyamide resin, thermoplastic polyester resin such as polybutylene terephthalate (PBT), polyethylene, polypropylene, etc. The polyolefin resin is preferably used.
[0015]
For the upper and lower cases, a synthetic resin similar to the synthetic resin constituting the thrust slide bearing means is used, but in particular, a good combination of the synthetic resin used for the thrust slide bearing means and the sliding friction characteristics, Moreover, it is desirable that the synthetic resin is relatively high in rigidity. As an example of the desired combination, polyacetal resin is used for the upper case, polyamide resin is used for the lower case, polyolefin resin is used for the thrust slide bearing means, and it is integrally formed on the lower surface of the annular wide flange portion of the upper case as thrust slide bearing means. There is a combination in which polyacetal resin is used for the upper case having the annular thrust bearing portion and polyamide resin or PBT is used for the lower case.
[0016]
  The synthetic resin bearing of the present invention is incorporated in a strut type suspension (McPherson type) in a four-wheeled vehicle, and is used by being disposed between a mounting member of a vehicle body and an upper spring seat of a strut assembly. When the strut assembly is rotated by the steering operation, the lower case is rotated with respect to the upper case, and the rotation of the lower case is caused by a synthetic resin thrust slide formed between the upper case and the lower case. The bearing means smoothly allows the steering operation to be performed smoothly. Even when a radial load is applied to a synthetic resin bearing, the radial load isRadial bearing formed by holding a bearing gap between the inner peripheral surface of the cylindrical portion of the upper case and the outer peripheral surface of the cylindrical portion of the lower caseIs allowed smoothly by sliding contact between synthetic resins.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in more detail based on preferred examples shown in the drawings. The present invention is not limited to these examples.
[0018]
【Example】
  In FIG. 1, the synthetic resin bearing 10 of this example includes a synthetic resin lower case 20 and a lower case.UnitedAn upper case 30 made of synthetic resin;Formed between upper case and lower caseAnd a synthetic resin thrust sliding bearing means 40.
[0019]
The lower case 20 has a cylindrical portion 22 having an inner surface 21 as an engagement hole, an annular wide flange portion 23 extending on the outer peripheral surface of the end portion of the cylindrical portion 22, and the cylindrical portion 22 on the upper surface of the annular wide flange portion 23. An annular recess 25 is formed by an annular protrusion 25 erected by forming an annular groove 24, the annular protrusion 25, and the upper surface of the annular wide flange portion, and is provided on the outer peripheral edge of the wide flange portion 23. And an annular engagement protrusion 27. The annular engagement protrusion 27 is connected to the outer peripheral surface of the taper surface part inclined outward from the end of the protrusion part 27 and the taper surface part, and forms an annular convex corner part to form the wide flange part. The engaging part 28 which consists of a taper surface part connected to the outer peripheral surface of 23 is comprised.
[0020]
The upper case 30 includes a cylindrical portion 31, an annular wide flange portion 32 extending on the outer peripheral surface of the end portion of the cylindrical portion 31, and an annular flange portion 33 extending radially inward at the other end of the cylindrical portion 31. An annular engagement hanging portion 34 is provided at the outer peripheral edge of the wide flange portion 32. The annular engagement hanging portion 34 has a tapered surface portion that is inclined outwardly from the base portion on the inner peripheral surface thereof, and a tapered surface portion that is continuous with the tapered surface portion and forms an annular concave corner portion and is continuous with the lower end of the hanging portion 34. The engaging hook part 35 which consists of these is comprised.
[0021]
  The upper case 30 is located between the inner peripheral surface of the cylindrical portion 31 and the outer peripheral surface of the cylindrical portion 22 of the lower case 20.A radial bearing is formed by holding the bearing gap, andThe lower surface of the annular flange 33 faces the end surface of the cylindrical portion 22 of the lower case 20, and the engagement hook portion 35 of the annular engagement hanging portion 34 is engaged with the engagement portion 28 of the annular engagement protrusion 27 of the lower case 20. It is combined with the lower case 20 with elastic attachment. Between the upper and lower cases 30, 20 combined in this way, an outer side elastic mounting portion, a lower surface of the inner peripheral side annular flange portion 33, and a facing portion between the end surface of the cylindrical portion 22 of the lower case 20 are externally provided. A sealing portion is formed to prevent foreign matters such as dust from entering the bearing sliding surface.
[0022]
The thrust slide bearing means 40 is formed in a space between the annular recess 26 of the lower case 20 and the lower surface of the annular wide flange 32 of the upper case 30 facing the annular recess 26, and the bottom surface of the annular recess 26 and the annular wide flange portion. The annular thrust bearing body 41 is slidably arranged on the lower surface, has an inner diameter larger than the outer diameter of the annular protrusion 25 of the lower case 20, and has an outer diameter smaller than the inner diameter of the annular engagement protrusion 27. Consists of. On both end faces of the bearing body 41, a ring groove 42 is formed at the periphery on the inner diameter side, and a plurality of radial grooves 43 opening from the ring groove 42 to the outer diameter side are equally spaced in the circumferential direction. And with a phase difference of 30 degrees. The ring groove 42 and the radial groove 43 serve as a reservoir for a lubricant such as grease.
[0023]
  FIG. 3 shows another specific example. The synthetic resin bearing 10 of this example is similar to the above-described synthetic resin bearing in that the annular engagement protrusion 27 and the radial direction are formed on the upper surface of the annular wide flange 23 of the lower case 20. An outer annular projecting portion 25a that is erected by forming an annular groove 29 on the inner side is further provided, and the upper case 30 is formed on the lower surface of the annular wide flange portion 32 with the annular engagement hanging portion 34 and the radially inner side. Further, an annular hanging portion 37 is formed by hanging an annular groove 36. The upper case 30 has an inner peripheral surface of the cylindrical portion 31 and the cylindrical portion 22 of the lower case 20.A radial bearing is formed by holding a bearing gap between the outer peripheral surface, andThe bottom surface of the annular flange 33 faces the end surface of the cylindrical portion 22 of the lower case 20, and the end portion of the annular hanging portion 37 overlaps the end portion of the outer annular protrusion 25 a of the lower case 20 in the radial direction. A sealing portion by labyrinth action is formed and engaged with the overlapping portion, and the engagement hook portion 35 of the annular engagement hanging portion 34 is elastically attached to the engagement portion 28 of the annular engagement protrusion 27 of the lower case 20. Combined with the lower case 20.

[0024]
Between the upper and lower cases 30 and 20 combined in this way, an overlapping portion of the elastic mounting portion, the end of the annular hanging portion 37 and the end of the outer annular projecting portion 25a of the lower case 20 is provided on the outer peripheral side. A sealing portion formed by a labyrinth action is formed on the inner peripheral side, and a sealing portion is formed on the inner peripheral side of a facing portion between the lower surface of the annular flange 33 and the end surface of the cylindrical portion 22 of the lower case 20. Prevents dust from entering the bearing sliding surface.
[0025]
The synthetic resin bearing 10 configured as described above is assembled in the strut assembly shown in FIG. That is, the bearing 10 fits the inner surface 21 of the cylindrical portion of the lower case 20 to the outer peripheral surface of the cylindrical protrusion S1 of the upper spring seat S of the strut assembly, and the lower surface of the annular wide flange portion 23 on the upper spring seat. The cylindrical portion 31 of the upper case 30 is seated on the flat surface portion S2 of S, and the upper surface of the annular wide flange portion 32 of the upper case 30 is set to the lower surface of the vehicle body side mounting member F. It is made to contact | abut and is arrange | positioned between the upper spring seat S and the vehicle body side attachment member F. FIG. In FIG. 4, symbol R indicates a piston rod of a strut assembly, and symbol B indicates a coil spring.
[0026]
  When a radial load due to the suspension structure acts on the synthetic resin bearing 10 disposed between the upper spring seat S and the vehicle body side mounting member F, the radial load is applied to the cylindrical portion 31 of the upper case 30. It is smoothly allowed by the sliding of the synthetic resin in the radial bearing portion formed by holding the bearing gap between the inner peripheral surface and the outer peripheral surface of the cylindrical portion 22 of the lower case 20. The vehicle weight isIt is arranged in a space between the annular recess 26 of the lower case 20 and the lower surface of the annular wide flange 32 of the upper case 30 facing the annular recess 26, and on the bottom surface of the annular recess 26 and the lower surface of the annular wide flange 32. It is supported by a thrust slide bearing means 40 formed of an annular thrust bearing body 41 made of a synthetic resin and slidably arranged.At the same time, the thrust load is smoothly allowed by the sliding of the synthetic resin between the annular recess 26 of the lower case 20, the annular thrust bearing body 41, and the lower surface of the annular wide flange portion 32 of the upper case 30.
[0027]
  FIG. 5 shows another specific example. The synthetic resin bearing 10 of this example is the same as the above-described synthetic resin bearing shown in FIG. Further, a cylindrical wall portion 22b extending downward is provided, and the annular projecting portion 25 forms an annular groove 24 with the cylindrical wall portion 22b.RingIt is erected on the upper surface of the wide flange 23. Further, the upper case 30 is extended downward on the inner peripheral surface of the cylindrical portion 31 through an enlarged diameter annular shoulder portion 31a.RingAn inner annular hanging portion 37a that hangs down from the lower surface of the wide collar portion 32 is further provided. AndThe upper case 30 forms a radial bearing portion by holding a bearing gap between the inner peripheral surface of the cylindrical portion 31 and the outer peripheral surface of the cylindrical portion 22 of the lower case 20, andThe bottom surface of the annular flange 33 faces the end surface of the cylindrical portion 22 of the lower case 20, and the enlarged annular shoulder portion 31a faces the enlarged annular shoulder portion 22a of the lower case 20, respectively. Is overlapped in the radial direction with the end of the annular protrusion 25 of the lower case 20Form a sealing part by labyrinth action on the overlapping partAs well as engageThe engagement hook portion 35 of the annular engagement hanging portion 34 is connected to the engagement portion 28 of the annular engagement protrusion 27 of the lower case 20.The lower case 20 is combined elastically. Was combined like thisBetween the upper case 30 and the lower case 20The facing portion of the elastic mounting portion on the outer peripheral side, the lower surface of the annular flange portion 33 on the inner peripheral side and the end surface of the cylindrical portion 22 of the lower case 20, the end portion of the inner annular hanging portion 37 a, and the annular protruding portion 25 of the lower case 20. With the end ofRadialThe overlapping portion is formed with a sealing portion for preventing foreign matters such as dust from entering the bearing sliding surface from the outside.
[0028]
  FIG. 6 shows still another specific example. The synthetic resin bearing 10 of this example is the same as the synthetic resin bearing shown in FIG. 5 except that the lower case 20 protrudes from the upper surface of the annular wide flange portion 23. And an outer annular protrusion 25a erected by forming an annular groove 29 radially inward of the portion 27, and the upper case30Is further provided on the lower surface of the annular wide collar 32 with an annular hanging portion 34 and an annular hanging portion 37 that is suspended by forming an annular groove 36 radially inside. And the upper case 30 isA radial bearing portion is formed by holding a bearing gap between the inner peripheral surface of the cylindrical portion 31 and the outer peripheral surface of the cylindrical portion 22 of the lower case 20, and the lower surface of the annular flange 33 is placed on the lower surface of the lower case 20. On the end surface of the cylindrical portion 22, the enlarged diameter annular shoulder portion 31 a faces the enlarged diameter annular shoulder portion 22 a of the lower case 20, and the end portion of the inner annular hanging portion 37 a is the end of the annular projecting portion 25 of the lower case 20. And the end portion of the annular hanging portion 37 are overlapped with the end portion of the outer annular projecting portion 25a of the lower case 20 in the radial direction thereof, and a sealing portion by a labyrinth action is formed and engaged with the overlapping portion. WithThe engagement hook portion 35 of the annular engagement hanging portion 34 is elastically attached to the engagement portion 28 of the annular engagement protrusion 27 of the lower case 20 and is combined with the lower case 20.
[0029]
Between the upper and lower cases 30 and 20 combined in this way, on the outer peripheral side thereof is an overlapping portion of the elastic mounting portion, the end portion of the annular hanging portion 37 and the end portion of the outer annular projecting portion 25a of the lower case 20. A formed sealing portion by labyrinth action is formed, and on the inner peripheral side thereof, a facing portion between the lower surface of the annular flange portion 33 and the end surface of the cylindrical portion 22 of the lower case 20, the end portion of the inner annular hanging portion 37a, and the lower case A sealing portion by a labyrinth action is formed at a portion overlapping with the end portion of the 20 annular projecting portions 25, thereby preventing dust and the like from entering the bearing sliding surface from the outside.
[0030]
By the way, in the specific examples shown in FIGS. 1, 3, 5 and 6, the space between the annular recess 24 of the lower case 20 and the lower surface of the annular wide flange portion 33 of the upper case 30 facing the annular recess 24 is shown. The thrust slide bearing means 40 comprising the annular thrust bearing body 41 is formed in the space. Instead, as shown in FIGS. 7 to 10, the thrust slide bearing means 40 is replaced with the annular wide flange portion 32 of the upper case 30. An annular thrust bearing formed integrally with the lower surface of the lower case 20 and having an inner diameter larger than the outer diameter of the annular protrusion 25 of the lower case 20 and smaller than the inner diameter of the annular engagement protrusion 27 or the outer annular protrusion 25a. You may comprise from the protrusion 44. FIG. In the structure of the synthetic resin bearing 10 shown in FIGS. 7 to 10, the structure other than the thrust slide bearing means 40 is the same as the structure shown in FIGS. 1, 3, 5, and 6 described above.
[0031]
In the synthetic resin bearing 10 shown in FIGS. 7 to 10, the thrust load is allowed by sliding between the end surface of the annular thrust bearing protrusion 44 and the bottom surface of the annular recess 25 of the lower case 20. In this case, a ring groove and a radial groove are formed on the end face of the annular thrust bearing protrusion 44.
[0032]
【The invention's effect】
In the synthetic resin bearing of the present invention, even when a radial load due to the suspension structure acts, the radial load maintains a bearing gap between the outer peripheral surface of the cylindrical portion of the upper case and the inner peripheral surface of the cylindrical portion of the lower case. It is allowed smoothly by the sliding of the synthetic resin in the radial bearing portion formed in this way.
[Brief description of the drawings]
FIG. 1 is a sectional view of a synthetic resin bearing of the present invention.
2 is a plan view of a thrust slide bearing body in the synthetic resin bearing shown in FIG. 1. FIG.
FIG. 3 is a cross-sectional view showing still another specific example of the synthetic resin bearing of the present invention.
4 is a cross-sectional view of a state in which the synthetic resin bearing shown in FIG. 3 is assembled in a strut assembly.
FIG. 5 is a cross-sectional view showing another specific example of the synthetic resin bearing of the present invention.
FIG. 6 is a cross-sectional view showing another specific example of the synthetic resin bearing of the present invention.
FIG. 7 is a cross-sectional view showing another specific example of the synthetic resin bearing of the present invention.
FIG. 8 is a cross-sectional view showing another specific example of the synthetic resin bearing of the present invention.
FIG. 9 is a sectional view showing another specific example of the synthetic resin bearing of the present invention.
FIG. 10 is a cross-sectional view showing another specific example of the synthetic resin bearing of the present invention.
FIG. 11 is a sectional view of a conventional synthetic resin bearing.
12 is a cross-sectional view showing a state in which the synthetic resin bearing shown in FIG. 11 is assembled in a strut assembly.
[Explanation of symbols]
10 Synthetic resin bearings
20 Lower case
21 Inside
22 Cylindrical part
23 Annular wide collar
25 Annular protrusion
26 annular recess
27 Annular engagement protrusion
30 Upper case
31 Cylindrical part
32 Annular wide collar
33 Ring collar
34 Annular engagement hanging part
40 Thrust slide bearing means
41 Annular thrust bearing body

Claims

Synthetic resin-made lower casing (20), and the combined the lower case synthetic resin upper case (30), the thrust sliding bearing means made of a formed synthetic resin between the upper case and the lower case ( 40) , and the lower case (20) includes a cylindrical portion (22) having an inner surface (21) as an insertion hole, and an annular wide flange portion (23 ) extending on the outer peripheral surface of the end portion of the cylindrical portion. ) and the annular recess in the upper surface of the annular wide cylindrical portion on the upper surface of the flange portion and the annular groove (24) annular protrusion formed to erected (25) and the annular projection and the annular wide collar portion annular engagement protrusion erected on the outer peripheral edge of the form (26) the annular wide collar portion includes a (27), the upper case (30) and the cylindrical portion cylindrical portion (31) extending in the radially inward end of the annular wide collar portion extending to an end portion outer peripheral surface (32) of the cylindrical portion Jotsuba portion (33) and the annular engagement suspended portion hanging down the outer peripheral edge of the annular wide collar portion includes a (34), the upper case (30) and the inner peripheral surface of the cylindrical portion (31) A radial gap is formed by holding a bearing gap between the lower case (20) and the outer peripheral surface of the cylindrical portion (22) , and the lower surface of the annular flange (33) is connected to the cylindrical portion (22 of the lower case ). ) And the annular engagement hanging portion (34) is elastically attached to the annular engagement protrusion (27) of the lower case and combined with the lower case, and the thrust slide bearing means (40) is A synthetic resin bearing formed in a space between the annular recess (26) of the lower case and the lower surface of the annular wide flange (32) of the upper case facing the annular recess.

The lower case (20) has an outer annular protrusion (25a ) which is erected by forming an annular groove (29) radially inward of the annular engagement protrusion (27 ) on the upper surface of the annular wide flange (23). ) , And the upper case (30) has a ring-like shape in which a ring-shaped engagement hanging portion (34) is formed on the lower surface of the ring-shaped wide flange portion (32) and an annular groove (36) is formed radially inwardly. It includes hanging portion (37) further, the upper case holds the bearing gap between the outer peripheral surface of the cylindrical portion (22) of the lower case and the inner peripheral surface of the cylindrical portion (31) (20) Te forms the radial bearing portion, and the lower surface of the annular flange portion (33) is opposed to the end surface of the cylindrical portion of the lower case (22), an outer annular projection of the lower casing end portion of the annular suspended portion (37) part end and the sealing portion by the labyrinth effect the superposition portion superposed in the radial direction of (25a) Synthetic resin bearing according annular engagement suspended portion is engaged with form to the (34) to claim 1, wherein the annular engagement protrusion of the lower case (27) to thereby resiliently fitting are combined in said lower case .

Synthetic resin-made lower casing (20), and the combined the lower case synthetic resin upper case (30), the thrust sliding bearing means made of a formed synthetic resin between the upper case and the lower case ( 40) , and the lower case (20) includes a cylindrical portion (22) having an inner surface (21) as an insertion hole, and an annular wide flange portion (23 ) extending on the outer peripheral surface of the end portion of the cylindrical portion. ) and cylindrical wall portion extending downwardly through the outer peripheral surface diameter annular shoulder portion (22a) of the cylindrical portion (22b) and said cylindrical wall portion on the upper surface of the annular wide collar portion and the annular groove (24) and the outer peripheral edge of the annular wide collar portion to form an annular recess (26) in the upper surface of the annular projection and the annular wide collar portion an annular protrusion formed to erected (25) includes annular engagement protrusion erected and (27), an upper casing (30) cylindrical portion (31) circular Expanding annular wide collar portion extending to an end portion outer peripheral surface of the part (32) and the annular flange portion extending radially inwardly to the other end of the cylindrical portion (33) on the inner peripheral surface of the cylindrical portion extended downward through diameter annular shoulder portion (31a), said annular widened inner annular depending portion extending downward to the lower surface of the flange portion (37a) and the annular engagement suspended portion hanging down the outer peripheral edge of the annular wide collar portion (34) and provided with a upper case (30) holds the bearing gap between the outer peripheral surface of the cylindrical portion (22) of the lower case and the inner peripheral surface of the cylindrical portion (31) (20) to form a radial bearing portion, and the end surface of the cylindrical portion of the lower case to the lower surface of the annular flange portion (33) (22), the enlarged diameter annular shoulder (31a) of enlarged diameter annular shoulder of the lower casing is opposed respectively to (22a), the ends and a diameter of the inner annular hanging part annular projection of said lower casing the ends of (37a) (25) Superimposed on direction annular engagement suspended portion (34) elastically is attached to the annular engagement protrusion of the lower case (27) is engaged with and forms a seal by the labyrinth effect in superposition portion lower portion Combined with the case, the thrust slide bearing means (40) is formed in a space between the annular recess (26 ) of the lower case and the lower surface of the annular wide flange (32) of the upper case facing the annular recess. synthetic resin bearing which is characterized by being.

The lower case (20) has an outer annular protrusion (25a ) which is erected by forming an annular groove (29) radially inward of the annular engagement protrusion (27 ) on the upper surface of the annular wide flange (23). ) further comprises a upper case (30) on the lower surface of the annular wide collar portion (33), was suspended to form an annular groove (36) and the radially inward annular engaging suspended portion (34) and further comprising an annular suspended portion (37), the upper casing retaining the bearing gap between the outer peripheral surface of the cylindrical portion (22) of the lower case and the inner peripheral surface of the cylindrical portion (31) (20) to form a radial bearing portion, and the end surface of the cylindrical portion of the lower case to the lower surface of the annular flange portion (33) (22), the enlarged diameter annular shoulder (31a) of enlarged diameter annular shoulder of the lower casing is opposed respectively to (22a), the annular projecting portion of the lower case the end of the inner annular suspended portion (37a) And the end of the 25), an outer annular projection of the lower casing end portion end of (25a) and a sealing portion by the labyrinth effect the superposition portion superposed in the radial directions of the annular suspended portion (37) synthetic resin according is elastically mounted in claim 3, which is combined to the lower portion case the annular engaging projecting portion of the lower casing annular engagement suspended portion (34) is engaged with to form (27) bearing.

The space between the thrust sliding bearing means (40) includes a lower surface of the annular wide collar portion of the annular recess (26) and the upper casing facing the annular recess (26) (30) of the lower case (20) (32) And an annular thrust bearing body (41) made of synthetic resin and slidably disposed on the bottom surface of the annular recess (26) and the lower surface of the annular wide flange portion (32). The synthetic resin bearing as described in any one of 1-4.

The thrust slide bearing means (40) is a space between the annular recess (26 ) of the lower case (20) and the lower surface of the annular wide flange (32) of the upper case (30) facing the annular recess (26). disposed, is formed by the bottom surface thrust bearing collision portion of the annular formed integrally on the lower surface of the slidably arranged the annular wide collar portion (32) relative to the annular recess (26) (44) synthetic resin bearing according to claim 1, any one of 4 to have.