JP2004218689A

JP2004218689A - Pulley unit

Info

Publication number: JP2004218689A
Application number: JP2003004684A
Authority: JP
Inventors: Osamu Morita; 修森田
Original assignee: NSK Ltd
Current assignee: NSK Ltd
Priority date: 2003-01-10
Filing date: 2003-01-10
Publication date: 2004-08-05

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that the coming-off of a pulley member from an outer ring of a support bearing press-fitted in-between a sleeve member or the integral coming-off of the pulley member and the support bearing from the sleeve member occurs owing to the increase or the like of the axially acting force during driving of a belt when an engine is changed in a pulley unit of an automobile engine. <P>SOLUTION: A one-way roller clutch 38 is press-fitted between the pulley member 1, in which a pulley groove 37 is formed on the outer periphery, and the sleeve member 2, in which an accessory drive shaft is fixed to the inner periphery. The support bearings 3, 4 are press-fitted on its both sides. Snap ring grooves to be conformed with each other are formed at a part opposing to the pulley member 1 and the outer ring 5. A C-shaped snap ring 14 on the pulley side is fitted into it. Accordingly, the axial relative movement of both members is prevented. Similarly, snap ring grooves to be conformed with each other are formed at a part opposing to the sleeve member 2 and an inner ring 6. A C-shaped snap ring 33 on the sleeve side is fitted into it. Accordingly, the axial relative movement of both members is prevented. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、自動車のスターターやオールタネータ用プーリ等の自動車エンジンの補機プーリなどに用いるプーリユニットに関し、特にこのようなプーリユニットに用いるサポート軸受またはプーリが軸方向に抜けにくい構造とし、ユニットの信頼性を向上させるようにしたプーリユニットに関する。
【０００２】
【従来の技術】
自動車の走行用エンジンを駆動源として種々の補機が駆動されており、例えば自動車に必要な発電を行うオルタネータを駆動する際には、エンジンの回転角速度変動の影響によるベルトの保護等のため、一方向クラッチを内蔵したプーリユニットを用いている。
【０００３】
この一方向クラッチ付きのプーリユニット４０においては、例えば図６に示すように、外周面にエンジンのクランク軸で駆動されるベルトが掛けられるベルト溝４１を有し、内周面に一方向クラッチの軌道を形成し、あるいは軌道部材４２を圧入したプーリ部材４３と、外周面に一方向クラッチの軌道を形成し、あるいは軌道部材４４を圧入するとともに内周面に補機の回転軸と結合する嵌合孔４５を形成したスリーブ部材４６とを備え、このプーリ部材４３の軌道部材４２とスリーブ部材４６の軌道部材４４の間にニードルローラ４７を介在させ、そのニードルローラ４７を常にロック側に押している板バネやコイルバネ等のバネ、そのバネを固定している保持器等の部材によって一方向ローラクラッチ４８を構成している。
【０００４】
更に、上記一方向ローラクラッチ４８の軸方向両側にサポート軸受５０、５０を設けており、このサポート軸受５０、５０は、プーリ部材４３とスリーブ部材４６とのラジアル空間に、プーリユニット４０の両側から各々圧入して固定している。それにより、サポート軸受５０の外輪５１はプーリ部材４３に、また内輪５２はスリーブ部材４６に固定され、この転がり軸受からなるサポート軸受５０によりクラッチが外れた状態におけるプーリ部材４３とスリーブ部材４６との間自由な回転を確保している。
【０００５】
このような構造のプーリユニット４０においては、駆動時に発生する負荷トルクをローラクラッチがロックすることで駆動力を伝達する。また、速度変動及び微少角速度変動が発生した場合には、ローラクラッチがオーバーランすることにより、上記のようにプーリ部材４３とスリーブ部材４６との間の自由な回転を行うことによって、ベルトのスリップや鳴き等の現象を防止し、ベルト寿命の向上を図っている。
【０００６】
前記プーリユニット４０の組み立てに際しては、図７に一部を拡大して示すように、プーリ部材４３とスリーブ部材４６との間に一方向ローラクラッチ４８を圧入して固定した後、次いでサポート軸受５０を図示のようにプーリ部材４３とスリーブ部材４６との間に圧入し、スリーブ部材４６の外周面両側に形成した段差部５３に対して、サポート軸受５０の内輪５２における内側端面５４の角部５５を当接させることにより所定の構造に組み立てている。このように、各々のサポート軸受５０はスリーブ部材４６の段差部５３によって軸方向の動きが規制されるため、この段差方向に対しては移動できない構造となっている。
【０００７】
なお、上記のように一方向ローラクラッチをそなえたプーリユニットにおいて、プーリ部材とスリーブ部材との間にサポート軸受を圧入し、スリーブ部材の外周面両側に形成した段差部に対して、サポート軸受を当接するようにしたプーリユニットは特許文献１に記載されている。
【０００８】
【特許文献１】
特開平１４−１３０４３３号公報
【０００９】
【発明が解決しようとする課題】
上記のような従来のプーリユニット４０においては、サポート軸受５０をプーリ部材４３とスリーブ部材４６との間に圧入して固定するに際してその圧入荷重は、プーリ部材４３にかかるベルト張力変動やプーリ部材４３のミスアライメント、更には装置全体に作用する車体振動などの外力を考慮して最適な値になるように設計している。それに対して、特定の車両に最適なように上記のような種々の条件を考慮して圧入荷重を設定していた場合であっても、例えばその車両のエンジンが大排気量化した場合には、上記のようなベルト張力変動が増大し、ミスアライメントの影響も増大し、更には車体振動等の外力が大きくなる。そのような場合は、当初設定していた最適な圧入荷重では不十分となるので、その圧入荷重を大きくする必要がある。
【００１０】
しかしながら、単にサポート軸受の圧入荷重を大きくすると、その圧入荷重によって軸受内輪の割れが発生し、また製品化のための部品組立性が悪化し、更に軸受すきまの減少等によって耐焼付性が悪化する等の懸念がある。したがって、ここで用いられるサポート軸受５０には大きな圧入荷重を設定することができず、現状の圧入荷重程度を維持せざるを得ない。しかしながらこのように圧入荷重を現状程度のままに維持した場合は、従来のプーリユニットの構造では、このサポート軸受５０の軸線方向に対する移動の内、段差方向に対しては各サポート軸受５０はスリーブ部材４６の段差部５３によって移動できない構造となっているものの、逆方向に対しては前記のようなサポート軸受の圧入を行うため、そのような構造にはなっていない。
【００１１】
そのため、例えばこのプーリユニット４０が図６に示すようにエンジン補機方向と反エンジン補機方向になるように配置している場合において、ベルト溝４１に掛けられたベルトの作用によってプーリ部材４３にエンジン補機方向に力が作用したとき、その力がプーリ部材４３とサポート軸受５０の外輪５１との前記圧入による固着力より大きく、且つプーリ部材４３とサポート軸受５０の外輪５１との固着力が、スリーブ部材４６とサポート軸受５０の内輪５２との固着力より小さい時には、プーリ部材４３が外輪５１からエンジン補機側に移動し、いわゆる「抜け」が発生して不安定な回転を行うこととなる。
【００１２】
また、上記のようにプーリ部材４３に補機方向に力が作用したとき、その力がスリーブ部材４６とサポート軸受５０の内輪５２との固着力より大きく、且つプーリ部材４３とサポート軸受５０の外輪５１との固着力より小さい時には、プーリ部材４３とサポート軸受５０が一体となってエンジン補機側に移動し、不安定な回転を行うとともに、図６中の右側のサポート軸受５０がスリーブ部材４６から抜け出してしまうこともある。
【００１３】
逆に、プーリ部材４３に対して補機と反対方向に力が作用した場合には、その力がプーリ部材４３とサポート軸受５０の外輪５１との固着力より大きく、且つプーリ部材４３とサポート軸受５０の外輪５１との固着力が、スリーブ部材４６とサポート軸受５０の内輪５２との固着力より小さい時には、プーリ部材４３が外輪５１から反エンジン補機側に移動し、不安定な回転を行うとともに、甚だしい場合はプーリ部材４３が抜け出す事ともなる。
【００１４】
更に、上記のようにプーリ部材４３にエンジン補機方向に力が作用したとき、その力がスリーブ部材４６とサポート軸受５０の内輪５２との固着力より大きく、且つそのスリーブ部材４６とサポート軸受の内輪５２との固着力が、プーリ部材４３とサポート軸受５０の外輪５１との固着力より小さい時には、プーリ部材４３とサポート軸受５０が一体となってエンジン補機側に移動し、不安定な回転を行うとともに、図６中右側のサポート軸受４０がスリーブ部材４６から抜け出してしまうこともある。
【００１５】
したがって本発明は、ローラクラッチを備えたプーリユニットにおいて、プーリ駆動時に発生するベルト張力変動、ミスアライメント、車体振動等によりプーリ部材にその軸線方向に大きな力が作用した場合でも、プーリ部材の抜けやプーリ部材とサポート軸受の一体的な抜けの発生を防止することができるプーリユニットとし、それによりサポート軸受の圧入荷重を大きく設定して抜けの発生防止をする必要が無く、圧入荷重を大きく設定することによる軸受内輪の割れや部品組立性の悪化、耐焼付性の悪化を防止し、更に、それらの防止手段を備えたプーリユニットを特別の工具を必要とせず、容易に組み立てることができるようにしたプーリユニットを得ることを目的とする。
【００１６】
【課題を解決するための手段】
本発明によるプーリユニットは上記課題を解決するため、プーリとスリーブ間に、カム面を形成した軌道輪と円筒面を有する他方の軌道輪とが同心上に配置され、その間に複数のニードルローラを配置したローラクラッチと、前記ローラクラッチの自由回転を支持するためプーリユニット端面側からプーリとスリーブ間に圧入されるサポート軸受とを備えたプーリユニットにおいて、プーリ内周面、またはスリーブ外周面における、前記サポート軸受の前記プーリユニット端面側の側面に一致する位置に止め輪溝を形成し、前記止め輪溝内で拡開し、前記プーリから外輪が、または前記スリーブから内輪が脱落することを防止するＣ形止め輪を嵌入したものである。
【００１７】
また、プーリとスリーブ間に、カム面を形成した軌道輪と円筒面を有する他方の軌道輪とが同心上に配置され、その間に複数のニードルローラを配置したローラクラッチと、前記ローラクラッチの自由回転を支持するためプーリユニット端面側からプーリとスリーブ間に圧入されるサポート軸受とを備えたプーリユニットにおいて、軸受外輪の外周面とプーリ内周面、または軸受内輪の内周面とスリーブ外周面に、互いに対向して形成した止め輪溝と、前記止め輪溝に嵌入して拡開し、前記外輪とプーリ、または内輪とスリーブをキー止めするＣ形止め輪と、前記プーリ内周面に形成しプーリ端面側に拡開するテーパ部、または前記内輪内周面に形成し軸受圧入方向前方端面側に拡開するテーパ部とを備え、前記Ｃ形止め輪の最小縮径時の外径は、前記外輪の外径以下、またはスリーブ外径以下であり、前記外輪外周面に形成した止め輪溝、または前記スリーブ外周面に形成した止め輪溝は、前記Ｃ形止め輪が全て没する深さであり、前記プーリ内周面に形成した止め輪溝、または内輪内周面に形成した止め輪溝は、前記Ｃ形止め輪が嵌合して拡開時に、前記外輪とプーリ、または前記内輪とスリーブを該Ｃ形止め輪によりキー止めする深さであり、前記テーパ部の最大外径は、前記Ｃ形止め輪の自由拡開時の外径より大径であり、前記Ｃ形止め輪には、少なくとも前記サポート軸受の前記圧入時に前記テーパ部に当接する角部に対して曲面加工を施しても良い。このように構成することにより、軸受の外輪或いは内輪の脱落防止手段を、プーリユニット組立時に特別の工具を必要とせず、容易に組み込むことができる。
【００１８】
【発明の実施の形態】
本発明の実施例を図面に沿って説明する。図１には前記図６に示すプーリユニットとほぼ同様の構成を備えたプーリユニット２０に対して、本発明による後述するような止め輪固定部を適用した一実施例を示し、同実施例においては、図中右側のサポート軸受３についてはプーリ部材１とサポート軸受３の外輪５との間にプーリ部材側止め輪固定部２１を、またスリーブ部材２とサポート軸受３の内輪６との間においてはスリーブ部材側止め輪固定部２２を備えており、一方、図中左側のサポート軸受４については同様に、プーリ側止め輪固定部２３及びスリーブ側止め輪固定部２４を備えた例を示している。
【００１９】
但し、プーリユニットのサポート軸受の配置については種々の態様が存在し、図１に示すようにプーリユニット２０におけるローラクラッチ３８の両側にサポート軸受を設けるほか、片側にのみサポート軸受を設ける場合も存在するが、その際には止め輪固定部を備えたサポート軸受は当然片側のサポート軸受に対して適用される。
【００２０】
また、図１に示す実施例においては、左右のサポート軸受３、４に対して、各々プーリ部材１に対する外輪５の固定側、及びスリーブ部材２に対する内輪６の固定側の両方に止め輪固定部を設けた例を示しているが、例えばプーリ部材１に対する外輪５の固定側のみ、或いはスリーブ部材２に対する内輪６の固定側のみに設けても良い。
【００２１】
その際も、プーリユニットの一態様として、片側にのみサポート軸受を設ける場合には、そのサポート軸受についてプーリ部材１に対する外輪５の固定側のみ、或いはスリーブ部材２に対する内輪６の固定側のみに設けても、少なくとも前記従来のサポート軸受よりは確実に、プーリ部材の抜けの発生等の問題点を解消することができる。
【００２２】
以下、図２には図１の図中右側のサポート軸受３におけるプーリ部材１に対する外輪５の固定側における、プーリ部材側止め輪固定部２１を設けた例を示し、図３には図中右側のサポート軸受におけるスリーブ部材２に対する内輪６の固定側における、サポート部材側止め輪固定部２２を設けた例を示しているが、これらの止め輪固定部は、前記のように種々の態様で使用される。
【００２３】
図２には前記のように、図１に示した右側のサポート軸受３におけるプーリ側止め輪固定部２１のみを形成した例において、その要部拡大図を示しており、同図（ａ）はその組立後の状態を示し、同図（ｂ）〜（ｄ）は組立中の状態を更に要部拡大図で順に示している。
【００２４】
図２（ａ）に示す実施例においては、プーリ部材１の内周面７における図中右側端面８に近接する部分にプーリ部材側止め輪溝９を形成し、この内周面７におけるプーリ部材側止め輪溝９とプーリ部材１の図中右側端面８との間には、右側端面８側から順にテーパ部１０と平坦内面部１１を備えている。
【００２５】
一方、サポート軸受３の外輪５の外周面１２には外輪側止め輪溝１３を形成しており、この外輪側止め輪溝１３の位置は、図２（ａ）或いは同図（ｄ）に示すようなプーリ側止め輪固定部２１の組立終了状態において、前記プーリ部材１の内周面７に形成したプーリ部材側止め輪溝９と一致する位置に形成され、この組立終了状態、即ちこのプーリユニット２０の作動を行う状態においては、前記プーリ部材側止め輪溝９と外輪側止め輪溝１３によって、プーリ側Ｃ形止め輪１４を収容するＣ形止め輪収容部１５を形成している。
【００２６】
上記のように、プーリユニット２０の組立終了状態、即ちプーリ部材１とスリーブ部材２間にサポート軸受３を圧入し、サポート軸受３の内輪６の図中左側端面１６がスリーブ部材２の外周面１７に形成した段差部１８に当接している状態においては、Ｃ形止め輪収容部１５内にプーリ側Ｃ形止め輪１４が収容され、このプーリ側Ｃ形止め輪１４の半径方向外側への拡開反発力によって、プーリ側Ｃ形止め輪１４の外周がプーリ部材側止め輪溝９の内周面に圧接している。また、このプーリ側Ｃ形止め輪１４の角部にはＲ形状部を形成し、或いは面取りを形成する等の曲面形成加工を施している。
【００２７】
またこの状態において、プーリ側Ｃ形止め輪１４の径方向の厚さ部分は、プーリ部材１の内周面７と外輪５の外周面１２との圧接面部分にまたがっており、それによりプーリ部材１と外輪５とのキー止め作用を行う。したがってプーリ部材に対して、ベルト張力変動、ミスアライメント、車体振動等によりその軸線方向に大きな力が作用する場合において、プーリ部材１が図中右方向に移動しようとするときは、前記キー止め作用により、前記プーリ側Ｃ形止め輪１４が外輪側止め輪溝１３の側壁に当接して実質的に移動することができず、プーリ部材１が図中右側に移動することが阻止される。
【００２８】
上記のようなプーリ側Ｃ形止め輪１４をＣ形止め輪収容部１５に収容するには、サポート軸受３をプーリ部材１とスリーブ部材２との間に圧入するに際して、図２（ｂ）〜（ｄ）に示すように順に圧入することにより容易にプーリ側Ｃ形止め輪１４をＣ形止め輪収容部１５に収容可能としており、その作動を行うために同図（ｂ）及び（ｃ）に示すような各部の寸法が設定される。
【００２９】
即ち、図２（ｂ）に示すように、外輪５の外輪側止め輪溝１３にプーリ側Ｃ形止め輪１４を嵌合し、サポート軸受３を前記のようにプーリ部材１とスリーブ部材２との間に圧入するとき、プーリ側Ｃ形止め輪１４がプーリ部材１のテーパ部１０に当接するように各部の寸法を設定する。そのため、図２（ｂ）に示すように、テーパ部１０の最大外径Ｄ１はプーリ側Ｃ形止め輪１４の開放状態の外径Ｄ２よりＬ１だけ大きく設定している。
【００３０】
なお、このプーリ側Ｃ形止め輪１４は開放状態のため、その外径Ｄ２はプーリ側止め輪溝９の最大外径である溝内径Ｄ３よりＬ２だけ大きくなるように相互の寸法が設定される。それにより図２（ａ）及び（ｄ）に示すようにプーリ側Ｃ形止め輪１４がプーリ側止め輪溝１３に嵌合したとき、プーリ側Ｃ形止め輪１４がその拡開力によってプーリ側止め輪溝１３の内面に圧接することができるようになる。
【００３１】
図２（ｂ）の状態からサポート軸受３を図中矢印方向に圧入すると、プーリ側Ｃ形止め輪１４がテーパ部１０のテーパ面に押圧されて次第に縮径し、外輪側止め輪溝１３内に嵌合していく。このとき、プーリ側Ｃ形止め輪１４の特に外周側角部にＲ形状部、或いは面取り等の曲面形成加工を施しているため、更に容易に縮径することができる。その結果、同図（ｃ）に示すようにプーリ側Ｃ形止め輪溝１４が前記テーパ部１０の図中下端を過ぎて平坦内面部１１に位置するとき、プーリ側Ｃ形止め輪１４は外輪側止め輪溝１３内に完全に嵌入する。
【００３２】
このような作用を行わせるため、同図（ｃ）に示すように、プーリ側Ｃ形止め輪１４が上記のように平坦内面部１１に押圧されている状態において、プーリ側Ｃ形止め輪１４の内周面の直径Ｄ４は、外輪側止め輪溝１３の内周面の直径Ｄ５よりＬ３だけ大きくなるように設定する。
【００３３】
図２（ｃ）に示す状態から更に図中矢印の方向にサポート軸受３を圧入し、図２（ａ）に示すように、サポート軸受３の内輪６における図中左方向端面１６がスリーブ部材２の外周面１７に形成した段差部１８に当接するとき、同図（ｄ）に示されるようにプーリ部材側止め輪溝９と外輪側止め輪溝１３とが一致する。それによりプーリ側Ｃ形止め輪１４はプーリ部材１の平坦内面部１１による拘束が開放され、プーリ側止め輪溝９内に嵌合し、その際前記のようにプーリ側Ｃ形止め輪１４はその拡開力によってプーリ側止め輪溝１３の内面に圧接する。上記のようにして専用治具等を用いることなく、単にサポート軸受を圧入するのみで、容易にプーリ側Ｃ形止め輪１４をプーリ側止め輪溝１３内に嵌合させることができる。
【００３４】
このように、プーリ側Ｃ形止め輪１４がプーリ側止め輪溝１３内に嵌合している状態において、図２（ｄ）に示すように、プーリ部材１の内周面７の内径Ｄ６は、プーリ側Ｃ形止め輪１４のこの時の内径Ｄ７よりＬ４だけ大きく設定し、このプーリ側Ｃ形止め輪１４がプーリ部材１と外輪５の軸線方向への移動を止めるキーの作用を行うことができるようにする。
【００３５】
上記のようにして、プーリ部材１とサポート軸受３の外輪５とは、止め輪１４によってその軸線方向の相互の移動が阻止されるプーリ部材側止め輪固定部２１によって固定されることとなる。プーリユニット２０における上記固定構造により、例えばサポート軸受３の内輪６とスリーブ部材２との圧入が特に強固に行われているときは、前記プーリ部材側止め輪固定部２１によってプーリ部材１がサポート軸受３の外輪５と移動不能に固定されることにより、プーリ部材１に対して図中右側方向に大きな力が掛かっても、プーリ部材１が外輪５に対して軸線方向に移動することが無く、またプーリ部材１とサポート軸受３が一体的にスリーブ部材６に対して移動することもなくなる。
【００３６】
上記の例においては、図１のプーリユニット２０における図中右側のサポート軸受３において、プーリ部材１とサポート軸受３の外輪５との間におけるプーリ部材側止め輪固定部２１によって、プーリ部材１単独の、或いはサポート軸受３と一体的な軸線方向の移動を防止した例を示したものであるが、この構成は図１のプーリユニット２０における図中左側のサポート軸受４に対してもプーリ部材側止め輪固定部２３として同様に適用することができ、それによりプーリ部材１の図中左側方向への移動を同様にして阻止することができる。上記のように、左右のプーリ部材側止め輪固定部２１、２３のいずれかを設ける以外に、図１に示すように両方のプーリ部材側止め輪固定部２１、２３を設けることにより、プーリ部材の図中左右両方向に対してその移動を防止することができる。
【００３７】
一方、図１のプーリユニット２０に示されるようなスリーブ部材側止め輪固定部２２、２４については、図３に右側のサポート軸受３についてのスリーブ部材側止め輪固定部２２に示すような構成が採用される。即ち、この止め輪固定部２２はスリーブ部材２の外周面２６に形成した段差部２７にサポート軸受３の内輪６の図中左側端面１６が当接している状態において、スリーブ部材２の外周面２６の段差外周面３４に形成したスリーブ部材側止め輪溝３０と、サポート軸受３の内輪６の内周面に形成した内輪側止め輪溝３１とが、互いに対向してその位置が一致するように形成しており、両止め輪溝によって形成されるＣ形止め輪収容部３２中にスリーブ側Ｃ形止め輪３３を収容している。
【００３８】
この状態において、スリーブ側Ｃ形止め輪３３はその開放側に作用する力によって内輪側止め輪溝３１の内周面に対して圧接し、その厚さの略中間位置にスリーブ２の段差外周面３４と、これに圧入される内輪６の内周面３５の接触面が位置することにより、前記プーリ側Ｃ形止め輪１４と同様にキーの作用を行い、内輪６がスリーブ２から抜け出すことを防止している。それにより、プーリ部材１が前記のように図中右側に移動しようとするとき、プーリ部材１と外輪５とが強固に結合していることによりこの部分での移動が強力に阻止されている際に、プーリ部材１がサポート軸受３の全体とともに図中右側に移動しようとし、その際内輪６がスリーブ部材２から抜け出そうとすることを上記プーリ側Ｃ形止め輪１４によるキー止め作用によって防止することができる。
【００３９】
このような作用を行うスリーブ側Ｃ形止め輪３３の組み込みに際しては、図３（ｂ）〜（ｄ）に示すように、サポート軸受３をプーリ部材１とスリーブ部材２との間に圧入する際自動的に組み込みを行うことができるものであり、そのためにサポート軸受３の内輪６には、その図中左側端面部分にテーパ部３６を形成している。図３（ａ）に示すように、このテーパ部３６の拡開側の最大直径Ｄ９は、スリーブ部材２の外周面２６の外径Ｄ８よりＬ５だけ小さくなるように設定しており、それにより内輪６の図中左側端面がスリーブ部材２の段差部２７に当接することができるようになっている。
【００４０】
上記のように、サポート軸受３をプーリ部材１とスリーブ部材２との間に圧入するとき、自動的にスリーブ側Ｃ形止め輪３３を組み込むことができるように、且つスリーブ側Ｃ形止め輪３３が所定のキー止め作用を行うために、図３（ｂ）〜（ｄ）に示すように各部の寸法が設定される。
【００４１】
サポート軸受３をプーリ部材１とスリーブ部材２との間に圧入する際には、最初図３（ｂ）に示すようにスリーブ部材２のスリーブ部材側止め輪溝３０に、スリーブ側Ｃ形止め輪３３を拡開してはめ込む。この状態でサポート軸受３を図中右側からスリーブ部材２の段差外周面３４に圧入すると、内輪６の図中左側のテーパ部３６にスリーブ側Ｃ形止め輪３３が接触し、更に圧入するとその力によってスリーブ側Ｃ形止め輪３３は縮径し、スリーブ部材側止め輪溝３０内に次第に入り込む。特に、スリーブ側Ｃ形止め輪３０の外周の角部分にＲ形状部、或いは面取り部等の曲面加工を施すことにより、前記縮径がスムーズに行われる。このような作動を行わせるため、図３（ｂ）に示すように、テーパ部３６の最大外径Ｄ９は、スリーブ側Ｃ形止め輪３３の自由状態の外径Ｄ１０よりＬ６だけ大きくなるように設定している。
【００４２】
図３（ｂ）の状態から更にサポート軸受３を圧入すると、同図（ｃ）に示すように、テーパ部３６がスリーブ部材側止め輪溝３０を通過するとき、サポート側Ｃ形止め輪３３は内輪６の内周面３５に押圧された状態となり、サポート部材側止め輪溝３０内に全て嵌入する。このような作用を行わせるため、同図（ｃ）に示すように、サポート部材側止め輪溝３０の底面を形成する部分の直径Ｄ１２は、上記のようにサポート側Ｃ形止め輪３３が全て入り込んだ時の内周の直径Ｄ１１よりＬ７だけ小さくなるように設定している。
【００４３】
図３（ｃ）の状態から更にサポート軸受を圧入すると、最終的に同図（ａ）に示すように内輪６の図中左側端面がスリーブ部材２の段差部２７に当接して停止する。この時前記のように、スリーブ部材２の段差外周面３４に形成したスリーブ部材側止め輪溝３０と、サポート軸受３の内輪６の内周面に形成した内輪側止め輪溝３１とが互いに対向してその位置が一致し、両止め輪溝によって形成されるＣ形止め輪収容部３２中にスリーブ側Ｃ形止め輪３３が収容される。この状態でスリーブ側Ｃ形止め輪３３は前記のようにキー止め作用を行うために、同図（ｄ）に示すようにスリーブ側Ｃ形止め輪３３が内輪側止め輪溝３１の底面に圧接している状態における最小内径Ｄ１４は、スリーブ部材２の段差外周面３４の直径Ｄ１３よりＬ８だけ大きくなるように設定している。
【００４４】
上記のように図２に示す例においては、プーリ部材１とサポート軸受３の外輪５とをサポート側Ｃ形止め輪１４によってキー止め作用を行わせるプーリ側止め輪固定部２１を備え、また図３に示す例においては、スリーブ部材２とサポート軸受３の内輪６とをスリーブ側Ｃ形止め輪３３によってキー止め作用を行わせるスリーブ側止め輪固定部２２を備えた例を示したが、図１に示すプーリユニット２０の左側サポート軸受４に対してプーリ側止め輪固定部２３として、またスリーブ側止め輪固定部２４として適用しても良い。
【００４５】
また、左右両方のサポート軸受において、各々図２に示す態様のプーリ側止め輪固定部２１のみを設け、或いは図３に示す態様のスリーブ側止め輪固定部２２のみを設けても良い。更に、図１に示すように、左右のサポート軸受に対して図２及び図３に示す態様の止め輪固定部を全て適用しても良く、その際にはスリーブ部材の抜け、或いはスリーブ部材とサポート軸受と一体化した抜けの発生を確実に防止することができる。
【００４６】
なお、上記実施例においてはサポート軸受をプーリユニットにおける一方向ローラクラッチ部の両側に設けた例を示したが、その使用条件により片側のみにサポート軸受を配置したものに適用しても良いことは前記の通りであり、またサポート軸受として図示するような玉軸受以外に、転動体として円筒、或いはニードルを用いた軸受に適用することもできる。
【００４７】
上記実施例はいずれも軸受外輪の外周面とプーリ内周面、または軸受内輪の内周面とスリーブ外周面に、互いに対向して形成した止め輪溝と、前記止め輪溝に嵌入して拡開し、前記外輪とプーリ、または内輪とスリーブをキー止めするＣ形止め輪を用いた例を示したが、それ以外に例えば図４に示すように、プーリ部材１の内周面７における、サポート軸受３、４の側面において、プーリユニット端面としてのプーリ部材１の端面３９側の側面に一致する前記内周面７の位置に止め輪溝２８、２８を形成し、更にスリーブ部材２の外周面１７における、サポート軸受３、４の側面において、プーリユニット端面としてのスリーブ部材２の端面２５側の側面に一致する前記外周面１７の位置に止め輪溝２８、２８を形成し、これらの止め輪溝２８に各々Ｃ形止め輪２９を嵌入することによってサポート軸受の外輪及び内輪の脱落防止を行っても良い。
【００４８】
図４に示す例においては、プーリ部材内周面７及びスリーブ部材外周面１７における、サポート軸受３、４の側面において、プーリユニット端面側の側面に一致する全ての位置に止め輪溝２８を形成し、止め輪溝２８内で拡開し、プーリ部材１から外輪が、またはスリーブ２から内輪が脱落することを防止するＣ形止め輪２９を嵌入した例を示したが、これらのうち少なくとも１つ設けるだけでも、従来のものよりは前記のような脱落防止にとって、より良い効果を奏することができる。
【００４９】
その他、上記のようなキー溝とＣ形止め輪による抜け止め手段を前記図４のように全ての部分に設ける以外に、例えば図５に示すようにその１つの部分に段部１９を形成しても良い。このような段部１９は、プーリ部材１とスリーブ部材２との間にサポート軸受３、４及び一方向ローラクラッチ３８を容易に組み込むことができる位置のみに配置する。
【００５０】
【発明の効果】
本発明は上記のように構成したので、ローラクラッチを備えたプーリユニットにおいて、プーリ駆動時に発生するベルト張力変動、ミスアライメント、車体振動等によりプーリ部材にその軸線方向に大きな力が作用した場合でも、プーリ部材の抜けやプーリ部材とサポート軸受の一体的な抜けの発生を確実に防止することができる。そのため、サポート軸受の圧入荷重を過大にする必要が無くなり、その圧入荷重が過大なときに生じる軸受内輪の割れの発生、製品化時の部品組立性の悪化、更に軸受すきまの減少等による耐焼付性の悪化を防止することができる。
【図面の簡単な説明】
【図１】本発明によるプーリユニットの一実施例を示す断面図である。
【図２】本発明の他の実施例の要部拡大断面図であり、（ａ）は組立終了状態の断面図であり、（ｂ）〜（ｄ）はその組立の過程を示す更に要部を拡大して示す断面図である。
【図３】本発明の更に他の実施例の要部拡大断面図であり、（ａ）は組立終了状態の断面図であり、（ｂ）〜（ｄ）はその組立の過程を示す更に要部を拡大して示す断面図である。
【図４】本発明の更に他の実施例の断面図である。
【図５】本発明の更に他の実施例の断面図である。
【図６】従来のプーリユニットの断面図である。
【図７】従来のプーリユニットの要部拡大断面図である。
【符号の説明】
１プーリ部材
２スリーブ部材
３、４サポート軸受
５外輪
６内輪
１４プーリ側Ｃ形止め輪
１８段差部
２０プーリユニット
２１プーリ部材側止め輪固定部
２２スリーブ部材側止め輪固定部
２３プーリ側止め輪固定部
２４スリーブ側止め輪固定部
３３スリーブ側Ｃ形止め輪
３７ベルト溝
３８一方向ローラクラッチ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pulley unit used for an auxiliary pulley of an automobile engine such as an automobile starter or an alternator pulley, and more particularly, a support bearing or a pulley used for such a pulley unit has a structure that is difficult to come off in the axial direction, and the reliability of the unit The present invention relates to a pulley unit that improves performance.
[0002]
[Prior art]
Various auxiliary machines are driven using a driving engine of an automobile as a driving source.For example, when driving an alternator that generates electric power necessary for an automobile, for protection of the belt due to the influence of fluctuations in rotational angular speed of the engine, etc. A pulley unit with a built-in one-way clutch is used.
[0003]
In this pulley unit 40 with a one-way clutch, for example, as shown in FIG. 6, the outer peripheral surface has a belt groove 41 on which a belt driven by a crankshaft of an engine is hung, and the inner peripheral surface has a one-way clutch. A pulley member 43 into which a raceway is formed or press-fitted with a raceway member 42, and a raceway of a one-way clutch is formed on the outer peripheral surface, or a raceway member 44 is press-fitted and fitted to the inner peripheral surface and coupled to the rotary shaft of an auxiliary machine A sleeve member 46 formed with a joint hole 45. A needle roller 47 is interposed between the track member 42 of the pulley member 43 and the track member 44 of the sleeve member 46, and the needle roller 47 is always pushed to the lock side. A one-way roller clutch 48 is constituted by a member such as a leaf spring or a coil spring and a member such as a cage that fixes the spring.
[0004]
Further, support bearings 50, 50 are provided on both axial sides of the one-way roller clutch 48, and the support bearings 50, 50 are provided in a radial space between the pulley member 43 and the sleeve member 46 from both sides of the pulley unit 40. Each is press-fitted and fixed. As a result, the outer ring 51 of the support bearing 50 is fixed to the pulley member 43 and the inner ring 52 is fixed to the sleeve member 46, and the pulley member 43 and the sleeve member 46 in a state where the clutch is released by the support bearing 50 formed of the rolling bearing. Free rotation is ensured.
[0005]
In the pulley unit 40 having such a structure, the driving force is transmitted by the roller clutch locking the load torque generated during driving. Also, when speed fluctuations and minute angular speed fluctuations occur, the roller clutch overruns, so that free rotation between the pulley member 43 and the sleeve member 46 as described above results in slipping of the belt. Prevents noise and squealing and improves belt life.
[0006]
When the pulley unit 40 is assembled, as shown in a partially enlarged view in FIG. 7, a one-way roller clutch 48 is press-fitted between the pulley member 43 and the sleeve member 46 and fixed, and then the support bearing 50. Is pressed between the pulley member 43 and the sleeve member 46 as shown in the figure, and the corner portion 55 of the inner end face 54 of the inner ring 52 of the support bearing 50 with respect to the stepped portion 53 formed on both sides of the outer peripheral surface of the sleeve member 46. Are assembled into a predetermined structure. Thus, each support bearing 50 has a structure in which movement in the axial direction is restricted by the stepped portion 53 of the sleeve member 46, so that it cannot move in the stepwise direction.
[0007]
In the pulley unit having the one-way roller clutch as described above, a support bearing is press-fitted between the pulley member and the sleeve member, and the support bearing is provided to the stepped portion formed on both sides of the outer peripheral surface of the sleeve member. A pulley unit that makes contact is described in Patent Document 1.
[0008]
[Patent Document 1]
Japanese Patent Laid-Open No. 14-130433
[0009]
[Problems to be solved by the invention]
In the conventional pulley unit 40 as described above, when the support bearing 50 is press-fitted between the pulley member 43 and the sleeve member 46 and fixed, the press-fitting load is caused by belt tension fluctuations applied to the pulley member 43 and the pulley member 43. In consideration of misalignment and external forces acting on the entire device, such as vehicle vibrations, it is designed to be an optimum value. On the other hand, even when the press-fit load is set in consideration of various conditions as described above so as to be optimal for a specific vehicle, for example, when the engine of the vehicle has a large displacement, The belt tension fluctuation as described above increases, the influence of misalignment also increases, and the external force such as vehicle body vibration increases. In such a case, the optimal press-fit load that was initially set is not sufficient, and it is necessary to increase the press-fit load.
[0010]
However, simply increasing the press-fit load of the support bearing will cause cracks in the bearing inner ring due to the press-fit load, deteriorate the assembly of parts for commercialization, and deteriorate the seizure resistance due to a decrease in bearing clearance. There are concerns. Therefore, a large press-fit load cannot be set for the support bearing 50 used here, and the current press-fit load must be maintained. However, when the press-fit load is maintained at the current level as described above, in the conventional pulley unit structure, each support bearing 50 is a sleeve member in the step direction of the movement of the support bearing 50 in the axial direction. Although the structure cannot be moved by the stepped portion 53 of 46, since the support bearing is press-fitted in the reverse direction, the structure is not such.
[0011]
Therefore, for example, when the pulley unit 40 is arranged so as to be in the direction of the engine accessory and the direction opposite to the engine accessory as shown in FIG. 6, the pulley member 43 is caused by the action of the belt hung on the belt groove 41. When a force acts in the direction of the engine accessory, the force is larger than the fixing force due to the press-fitting between the pulley member 43 and the outer ring 51 of the support bearing 50, and the fixing force between the pulley member 43 and the outer ring 51 of the support bearing 50 is greater. When the fixing force between the sleeve member 46 and the inner ring 52 of the support bearing 50 is smaller than that, the pulley member 43 moves from the outer ring 51 to the engine auxiliary machine side, and a so-called “disengagement” occurs, causing unstable rotation. Become.
[0012]
Further, when a force acts on the pulley member 43 in the auxiliary direction as described above, the force is larger than the fixing force between the sleeve member 46 and the inner ring 52 of the support bearing 50, and the outer ring of the pulley member 43 and the support bearing 50. When it is smaller than the adhering force to 51, the pulley member 43 and the support bearing 50 are integrally moved to the engine accessory side to perform unstable rotation, and the right support bearing 50 in FIG. Sometimes you get out of your way.
[0013]
Conversely, when a force acts on the pulley member 43 in the direction opposite to the auxiliary machine, the force is greater than the fixing force between the pulley member 43 and the outer ring 51 of the support bearing 50, and the pulley member 43 and the support bearing. When the adhering force between the outer ring 51 and the outer ring 51 is smaller than the adhering force between the sleeve member 46 and the inner ring 52 of the support bearing 50, the pulley member 43 moves from the outer ring 51 to the non-engine auxiliary machine side and performs unstable rotation. At the same time, the pulley member 43 comes out in a severe case.
[0014]
Further, when a force is applied to the pulley member 43 in the direction of the engine accessory as described above, the force is larger than the fixing force between the sleeve member 46 and the inner ring 52 of the support bearing 50, and the sleeve member 46 and the support bearing. When the adhering force to the inner ring 52 is smaller than the adhering force between the pulley member 43 and the outer ring 51 of the support bearing 50, the pulley member 43 and the support bearing 50 move together to the engine accessory side, and unstable rotation occurs. In addition, the right support bearing 40 in FIG. 6 may come out of the sleeve member 46.
[0015]
Therefore, according to the present invention, in a pulley unit including a roller clutch, even when a large force is applied to the pulley member due to fluctuations in belt tension, misalignment, vehicle body vibration, etc. that occur when the pulley is driven, A pulley unit that can prevent the pulley member and the support bearing from coming off integrally, so that it is not necessary to set the press-fit load of the support bearing to be large and prevent the occurrence of slip-out, and the press-fit load is set large. So that the inner ring of the bearing can be prevented from cracking, the parts can be easily assembled, and the seizure resistance can be prevented from being deteriorated. In addition, the pulley unit equipped with these prevention means can be easily assembled without the need for special tools. The purpose is to obtain a pulley unit.
[0016]
[Means for Solving the Problems]
In order to solve the above problems, a pulley unit according to the present invention has a raceway having a cam surface and a raceway having a cylindrical surface concentrically disposed between a pulley and a sleeve, and a plurality of needle rollers are interposed therebetween. In a pulley unit comprising an arranged roller clutch and a support bearing press-fitted between the pulley and the sleeve from the pulley unit end face side to support the free rotation of the roller clutch, on the pulley inner peripheral surface or the sleeve outer peripheral surface, A retaining ring groove is formed at a position coinciding with the side surface of the support bearing on the end face side of the pulley unit, and is expanded in the retaining ring groove to prevent the outer ring from the pulley or the inner ring from dropping from the sleeve. A C-shaped retaining ring is inserted.
[0017]
Further, between the pulley and the sleeve, a raceway ring having a cam surface and the other raceway ring having a cylindrical surface are arranged concentrically, and a roller clutch having a plurality of needle rollers disposed between them, In a pulley unit having a support bearing that is press-fitted between the pulley and the sleeve from the end surface side of the pulley unit to support rotation, the outer peripheral surface of the bearing outer ring and the inner peripheral surface of the pulley, or the inner peripheral surface of the bearing inner ring and the outer peripheral surface of the sleeve A retaining ring groove formed opposite to each other, a C-shaped retaining ring that fits and expands into the retaining ring groove, and is keyed to the outer ring and the pulley, or the inner ring and the sleeve, and an inner peripheral surface of the pulley. A taper portion that is formed and expands toward the pulley end surface side, or a taper portion that is formed on the inner peripheral surface of the inner ring and expands toward the front end surface side in the bearing press-fitting direction. Is less than or equal to the outer diameter of the outer ring or less than the outer diameter of the sleeve, and the C-shaped retaining ring is entirely submerged in the retaining ring groove formed on the outer circumferential surface of the outer ring or the retaining ring groove formed on the outer circumferential surface of the sleeve. The retaining ring groove formed on the inner circumferential surface of the pulley or the retaining ring groove formed on the inner circumferential surface of the pulley is the depth when the outer ring and the pulley are The inner ring and the sleeve are deeply keyed by the C-shaped retaining ring, and the maximum outer diameter of the tapered portion is larger than the outer diameter when the C-shaped retaining ring is freely expanded, and the C-shaped The retaining ring may be subjected to curved surface processing at least at a corner portion that comes into contact with the tapered portion when the support bearing is press-fitted. With this configuration, the means for preventing the outer ring or inner ring from falling off can be easily incorporated without requiring a special tool when the pulley unit is assembled.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment in which a retaining ring fixing portion described later according to the present invention is applied to a pulley unit 20 having substantially the same configuration as the pulley unit shown in FIG. For the support bearing 3 on the right side of the figure, a pulley member side retaining ring fixing portion 21 is provided between the pulley member 1 and the outer ring 5 of the support bearing 3, and between the sleeve member 2 and the inner ring 6 of the support bearing 3. Is provided with a sleeve member side retaining ring fixing portion 22, while the support bearing 4 on the left side in the figure similarly shows an example provided with a pulley side retaining ring fixing portion 23 and a sleeve side retaining ring fixing portion 24. Yes.
[0019]
However, there are various modes of arrangement of the support bearings of the pulley unit. As shown in FIG. 1, in addition to providing support bearings on both sides of the roller clutch 38 in the pulley unit 20, there are cases in which support bearings are provided only on one side. However, in this case, the support bearing provided with the retaining ring fixing portion is naturally applied to the support bearing on one side.
[0020]
Further, in the embodiment shown in FIG. 1, retaining ring fixing portions on both the fixed side of the outer ring 5 with respect to the pulley member 1 and the fixed side of the inner ring 6 with respect to the sleeve member 2 with respect to the left and right support bearings 3 and 4. However, for example, it may be provided only on the fixed side of the outer ring 5 with respect to the pulley member 1 or only on the fixed side of the inner ring 6 with respect to the sleeve member 2.
[0021]
Even in that case, as one aspect of the pulley unit, when the support bearing is provided only on one side, the support bearing is provided only on the fixed side of the outer ring 5 with respect to the pulley member 1 or only on the fixed side of the inner ring 6 with respect to the sleeve member 2. However, problems such as the occurrence of pulling out of the pulley member can be solved more reliably than at least the conventional support bearing.
[0022]
FIG. 2 shows an example in which a pulley member side retaining ring fixing portion 21 is provided on the support bearing 3 on the right side of FIG. 1 on the fixing side of the outer ring 5 with respect to the pulley member 1, and FIG. The support member side retaining ring fixing portion 22 is provided on the fixing side of the inner ring 6 with respect to the sleeve member 2 of the support bearing, but these retaining ring fixing portions are used in various modes as described above. Is done.
[0023]
FIG. 2 shows an enlarged view of the main part of the example in which only the pulley side retaining ring fixing portion 21 of the right support bearing 3 shown in FIG. 1 is formed, as shown above. The state after the assembly is shown, and FIGS. 5B to 5D sequentially show the state during the assembly in enlarged views of the main part.
[0024]
In the embodiment shown in FIG. 2A, a pulley member side retaining ring groove 9 is formed in a portion of the inner peripheral surface 7 of the pulley member 1 adjacent to the right end surface 8 in the figure, and the pulley member on the inner peripheral surface 7 is formed. Between the side retaining ring groove 9 and the right end surface 8 of the pulley member 1 in the figure, a tapered portion 10 and a flat inner surface portion 11 are provided in order from the right end surface 8 side.
[0025]
On the other hand, an outer ring side retaining ring groove 13 is formed on the outer peripheral surface 12 of the outer ring 5 of the support bearing 3, and the position of the outer ring side retaining ring groove 13 is shown in FIG. 2 (a) or FIG. 2 (d). In the assembly end state of the pulley side retaining ring fixing portion 21 as described above, the pulley side retaining ring fixing portion 21 is formed at a position coinciding with the pulley member side retaining ring groove 9 formed on the inner peripheral surface 7 of the pulley member 1. In the state in which the unit 20 is operated, the pulley-member-side retaining ring groove 9 and the outer-ring-side retaining ring groove 13 form a C-shaped retaining ring accommodating portion 15 that accommodates the pulley-side C-shaped retaining ring 14.
[0026]
As described above, the assembly of the pulley unit 20 is completed, that is, the support bearing 3 is press-fitted between the pulley member 1 and the sleeve member 2, and the left end surface 16 in the figure of the inner ring 6 of the support bearing 3 is the outer peripheral surface 17 of the sleeve member 2. The pulley side C-shaped retaining ring 14 is accommodated in the C-shaped retaining ring accommodating portion 15, and the pulley-side C-shaped retaining ring 14 extends outward in the radial direction. The outer periphery of the pulley-side C-shaped retaining ring 14 is in pressure contact with the inner peripheral surface of the pulley-member-side retaining ring groove 9 by the repulsion force. In addition, an R-shaped portion is formed at a corner portion of the pulley-side C-shaped retaining ring 14 or a curved surface forming process such as chamfering is performed.
[0027]
In this state, the radial thickness portion of the pulley-side C-shaped retaining ring 14 extends over the pressure contact surface portion between the inner peripheral surface 7 of the pulley member 1 and the outer peripheral surface 12 of the outer ring 5. 1 and the outer ring 5 are keyed. Therefore, when a large force acts on the pulley member in the axial direction due to fluctuations in belt tension, misalignment, body vibration, etc., when the pulley member 1 tries to move in the right direction in the figure, the keying action As a result, the pulley-side C-shaped retaining ring 14 cannot substantially move due to contact with the side wall of the outer-ring-side retaining ring groove 13, and the pulley member 1 is prevented from moving to the right side in the figure.
[0028]
In order to accommodate the pulley-side C-shaped retaining ring 14 as described above in the C-shaped retaining ring accommodating portion 15, when the support bearing 3 is press-fitted between the pulley member 1 and the sleeve member 2, FIG. As shown in (d), the pulley-side C-type retaining ring 14 can be easily accommodated in the C-shaped retaining ring accommodating portion 15 by press-fitting in order, and FIGS. The dimensions of each part as shown in FIG.
[0029]
That is, as shown in FIG. 2B, the pulley-side C-shaped retaining ring 14 is fitted into the outer ring-side retaining ring groove 13 of the outer ring 5, and the support bearing 3 is connected to the pulley member 1 and the sleeve member 2 as described above. The dimensions of each part are set so that the pulley-side C-shaped retaining ring 14 abuts against the tapered part 10 of the pulley member 1. Therefore, as shown in FIG. 2B, the maximum outer diameter D1 of the tapered portion 10 is set to be larger by L1 than the outer diameter D2 of the pulley-side C-shaped retaining ring 14 in the open state.
[0030]
Since the pulley-side C-shaped retaining ring 14 is in an open state, the outer diameter D2 is set such that the outer diameter D2 is larger than the groove inner diameter D3, which is the maximum outer diameter of the pulley-side retaining ring groove 9, by L2. . 2A and 2D, when the pulley-side C-type retaining ring 14 is fitted in the pulley-side retaining ring groove 13, the pulley-side C-type retaining ring 14 is moved to the pulley side by its expanding force. It can come into pressure contact with the inner surface of the retaining ring groove 13.
[0031]
2B, when the support bearing 3 is press-fitted in the direction of the arrow in the figure, the pulley-side C-shaped retaining ring 14 is pressed against the tapered surface of the tapered portion 10 and gradually reduces its diameter, and the inside of the outer-ring-side retaining ring groove 13 Fits into. At this time, since a curved surface forming process such as an R-shaped portion or chamfering is performed on the corner portion on the outer peripheral side of the pulley-side C-shaped retaining ring 14, the diameter can be further reduced. As a result, when the pulley side C-shaped retaining ring groove 14 is positioned on the flat inner surface portion 11 past the lower end of the tapered portion 10 as shown in FIG. Fits completely into the side retaining ring groove 13.
[0032]
In order to perform such an action, as shown in FIG. 5C, in the state where the pulley side C-shaped retaining ring 14 is pressed against the flat inner surface portion 11 as described above, the pulley-side C-shaped retaining ring 14 The diameter D4 of the inner peripheral surface is set to be larger than the diameter D5 of the inner peripheral surface of the outer ring side retaining ring groove 13 by L3.
[0033]
The support bearing 3 is further press-fitted in the direction of the arrow in the figure from the state shown in FIG. 2C, and as shown in FIG. 2A, the left end face 16 in the figure of the inner ring 6 of the support bearing 3 is the sleeve member 2. When contacting the stepped portion 18 formed on the outer peripheral surface 17, the pulley member side retaining ring groove 9 and the outer ring retaining ring groove 13 coincide with each other as shown in FIG. As a result, the pulley-side C-shaped retaining ring 14 is released from the restraint by the flat inner surface portion 11 of the pulley member 1 and is fitted into the pulley-side retaining ring groove 9. At this time, the pulley-side C-shaped retaining ring 14 is The expansion force makes pressure contact with the inner surface of the pulley side retaining ring groove 13. As described above, the pulley-side C-shaped retaining ring 14 can be easily fitted into the pulley-side retaining ring groove 13 by simply press-fitting the support bearing without using a dedicated jig or the like.
[0034]
Thus, in the state where the pulley-side C-shaped retaining ring 14 is fitted in the pulley-side retaining ring groove 13, the inner diameter D6 of the inner peripheral surface 7 of the pulley member 1 is as shown in FIG. The pulley-side C-shaped retaining ring 14 is set larger than the inner diameter D7 at this time by L4, and the pulley-side C-shaped retaining ring 14 functions as a key for stopping the pulley member 1 and the outer ring 5 from moving in the axial direction. To be able to.
[0035]
As described above, the pulley member 1 and the outer ring 5 of the support bearing 3 are fixed by the pulley member side retaining ring fixing portion 21 whose mutual movement in the axial direction is prevented by the retaining ring 14. For example, when the inner ring 6 of the support bearing 3 and the sleeve member 2 are particularly firmly pressed by the fixing structure in the pulley unit 20, the pulley member 1 is supported by the pulley member side retaining ring fixing portion 21. 3 so that the pulley member 1 does not move in the axial direction relative to the outer ring 5 even when a large force is applied to the pulley member 1 in the right direction in the figure. Further, the pulley member 1 and the support bearing 3 do not move relative to the sleeve member 6 integrally.
[0036]
In the above example, in the support bearing 3 on the right side in the drawing of the pulley unit 20 in FIG. 1, the pulley member 1 alone is provided by the pulley member side retaining ring fixing portion 21 between the pulley member 1 and the outer ring 5 of the support bearing 3. 1 or an example in which movement in the axial direction integral with the support bearing 3 is prevented, this configuration is also on the pulley member side with respect to the left side support bearing 4 in the pulley unit 20 of FIG. The same can be applied as the retaining ring fixing portion 23, whereby the movement of the pulley member 1 in the left direction in the figure can be similarly prevented. As described above, in addition to providing either of the left and right pulley member side retaining ring fixing portions 21 and 23, by providing both pulley member side retaining ring fixing portions 21 and 23 as shown in FIG. The movement can be prevented in both the left and right directions in FIG.
[0037]
On the other hand, the sleeve member side retaining ring fixing portions 22 and 24 shown in the pulley unit 20 of FIG. 1 have the configuration shown in FIG. 3 as the sleeve member side retaining ring fixing portion 22 of the right support bearing 3. Adopted. That is, the retaining ring fixing portion 22 is in the state in which the left end surface 16 in the figure of the inner ring 6 of the support bearing 3 is in contact with the stepped portion 27 formed on the outer circumferential surface 26 of the sleeve member 2. The sleeve member side retaining ring groove 30 formed on the step outer circumferential surface 34 and the inner ring side retaining ring groove 31 formed on the inner circumferential surface of the inner ring 6 of the support bearing 3 are opposed to each other so that their positions coincide with each other. The sleeve side C-shaped retaining ring 33 is accommodated in a C-shaped retaining ring accommodating portion 32 formed by both retaining ring grooves.
[0038]
In this state, the sleeve-side C-shaped retaining ring 33 is pressed against the inner peripheral surface of the inner ring-side retaining ring groove 31 by the force acting on the opening side thereof, and the stepped outer peripheral surface of the sleeve 2 is positioned approximately at the middle of its thickness. 34 and the contact surface of the inner peripheral surface 35 of the inner ring 6 that is press-fitted into this, the key acts like the pulley-side C-shaped retaining ring 14, and the inner ring 6 comes out of the sleeve 2. It is preventing. As a result, when the pulley member 1 is about to move to the right side in the drawing as described above, the pulley member 1 and the outer ring 5 are firmly connected to each other so that the movement in this portion is strongly prevented. Further, the pulley member 1 tries to move to the right side in the drawing together with the entire support bearing 3, and at this time, the inner ring 6 tries to come out of the sleeve member 2 by the keying action by the pulley side C-shaped retaining ring 14. be able to.
[0039]
When assembling the sleeve-side C-shaped retaining ring 33 that performs such an action, as shown in FIGS. 3B to 3D, when the support bearing 3 is press-fitted between the pulley member 1 and the sleeve member 2. For this purpose, the inner ring 6 of the support bearing 3 is formed with a tapered portion 36 at the left end surface portion in the drawing. As shown in FIG. 3 (a), the maximum diameter D9 on the expansion side of the tapered portion 36 is set to be smaller by L5 than the outer diameter D8 of the outer peripheral surface 26 of the sleeve member 2, whereby the inner ring The left end face in FIG. 6 can be brought into contact with the stepped portion 27 of the sleeve member 2.
[0040]
As described above, when the support bearing 3 is press-fitted between the pulley member 1 and the sleeve member 2, the sleeve side C-shaped retaining ring 33 can be automatically incorporated, and the sleeve-side C-shaped retaining ring 33 can be automatically incorporated. In order to perform a predetermined keying action, the dimensions of each part are set as shown in FIGS.
[0041]
When press-fitting the support bearing 3 between the pulley member 1 and the sleeve member 2, first, as shown in FIG. 3B, the sleeve side C-shaped retaining ring is inserted into the sleeve member side retaining ring groove 30 of the sleeve member 2. Expand 33 and fit. In this state, when the support bearing 3 is press-fitted into the outer peripheral surface 34 of the sleeve member 2 from the right side in the drawing, the sleeve-side C-shaped retaining ring 33 comes into contact with the tapered portion 36 on the left side of the inner ring 6 in the drawing, As a result, the diameter of the sleeve-side C-shaped retaining ring 33 is reduced and gradually enters the sleeve-member-side retaining ring groove 30. In particular, the diameter reduction is smoothly performed by applying curved surface processing such as an R-shaped portion or a chamfered portion to the corner portion of the outer periphery of the sleeve-side C-shaped retaining ring 30. In order to perform such an operation, as shown in FIG. 3B, the maximum outer diameter D9 of the tapered portion 36 is set to be larger by L6 than the outer diameter D10 of the sleeve-side C-shaped retaining ring 33 in the free state. It is set.
[0042]
When the support bearing 3 is further press-fitted from the state of FIG. 3B, when the taper portion 36 passes through the sleeve member side retaining ring groove 30 as shown in FIG. The inner ring 6 is pressed against the inner peripheral surface 35 and is fully inserted into the support member side retaining ring groove 30. In order to perform such an action, as shown in FIG. 6C, the diameter D12 of the portion forming the bottom surface of the support member side retaining ring groove 30 is the same as that of the support side C-shaped retaining ring 33 as described above. It is set to be smaller by L7 than the inner diameter D11 when entering.
[0043]
When the support bearing is further press-fitted from the state shown in FIG. 3C, the left end surface of the inner ring 6 in the drawing finally comes into contact with the stepped portion 27 of the sleeve member 2 and stops as shown in FIG. At this time, as described above, the sleeve member side retaining ring groove 30 formed on the stepped outer circumferential surface 34 of the sleeve member 2 and the inner ring side retaining ring groove 31 formed on the inner circumferential surface of the inner ring 6 of the support bearing 3 face each other. Then, the positions coincide with each other, and the sleeve side C-shaped retaining ring 33 is accommodated in the C-shaped retaining ring accommodating portion 32 formed by both retaining ring grooves. In this state, since the sleeve-side C-shaped retaining ring 33 performs the keying action as described above, the sleeve-side C-shaped retaining ring 33 is pressed against the bottom surface of the inner-ring-side retaining ring groove 31 as shown in FIG. The minimum inner diameter D14 in this state is set to be larger by L8 than the diameter D13 of the stepped outer circumferential surface 34 of the sleeve member 2.
[0044]
As described above, the example shown in FIG. 2 includes the pulley-side retaining ring fixing portion 21 that allows the pulley member 1 and the outer ring 5 of the support bearing 3 to be keyed by the support-side C-shaped retaining ring 14. In the example shown in FIG. 3, an example in which the sleeve side retaining ring fixing portion 22 that allows the sleeve member 2 and the inner ring 6 of the support bearing 3 to perform the keying action by the sleeve side C-shaped retaining ring 33 is shown. 1 may be applied as the pulley-side retaining ring fixing portion 23 and the sleeve-side retaining ring fixing portion 24 to the left support bearing 4 of the pulley unit 20 shown in FIG.
[0045]
Further, in both the left and right support bearings, only the pulley side retaining ring fixing portion 21 of the aspect shown in FIG. 2 may be provided, or only the sleeve side retaining ring fixing portion 22 of the aspect shown in FIG. 3 may be provided. Furthermore, as shown in FIG. 1, all of the retaining ring fixing portions shown in FIGS. 2 and 3 may be applied to the left and right support bearings. Occurrence of omissions integrated with the support bearing can be reliably prevented.
[0046]
In the above embodiment, an example is shown in which the support bearings are provided on both sides of the one-way roller clutch portion in the pulley unit. As described above, the present invention can be applied to a bearing using a cylinder or a needle as a rolling element in addition to a ball bearing as illustrated as a support bearing.
[0047]
In any of the above embodiments, the outer ring surface of the bearing outer ring and the inner peripheral surface of the pulley, or the inner ring surface of the bearing inner ring and the outer peripheral surface of the sleeve are opposed to each other, and are inserted into the retaining ring groove to expand. An example using a C-shaped retaining ring that opens and locks the outer ring and the pulley or the inner ring and the sleeve is shown, but other than that, for example, as shown in FIG. 4, on the inner peripheral surface 7 of the pulley member 1, Retaining ring grooves 28 and 28 are formed on the side surfaces of the support bearings 3 and 4 at the position of the inner peripheral surface 7 that coincides with the side surface on the end surface 39 side of the pulley member 1 as the pulley unit end surface. Retaining ring grooves 28 and 28 are formed on the side surface of the support bearings 3 and 4 on the surface 17 at the position of the outer peripheral surface 17 that coincides with the side surface on the end surface 25 side of the sleeve member 2 as the pulley unit end surface. Ring groove 2 It may be performed outer ring and the inner ring captive support bearing by each fitting the C-shaped snap ring 29.
[0048]
In the example shown in FIG. 4, the retaining ring groove 28 is formed at all positions on the side surfaces of the support bearings 3 and 4 on the pulley member inner peripheral surface 7 and the sleeve member outer peripheral surface 17 that coincide with the side surface on the pulley unit end surface side. In this example, a C-shaped retaining ring 29 that expands in the retaining ring groove 28 and prevents the outer ring from the pulley member 1 or the inner ring from dropping from the sleeve 2 is inserted. Even if only one of them is provided, a better effect can be obtained for preventing the dropout than the conventional one.
[0049]
In addition, the step 19 is formed in one part as shown in FIG. 5, for example, as shown in FIG. May be. Such a step portion 19 is disposed only at a position where the support bearings 3 and 4 and the one-way roller clutch 38 can be easily incorporated between the pulley member 1 and the sleeve member 2.
[0050]
【The invention's effect】
Since the present invention is configured as described above, in a pulley unit having a roller clutch, even when a large force acts on the pulley member in the axial direction due to fluctuations in belt tension, misalignment, vehicle body vibration, etc. that occur when the pulley is driven. Further, it is possible to reliably prevent the pulley member from coming off and the pulley member and the support bearing from coming off integrally. For this reason, it is not necessary to make the press-fit load of the support bearing excessive, seizure resistance due to cracking of the inner ring of the bearing that occurs when the press-fit load is excessive, deterioration of parts assembly at the time of commercialization, and reduction of bearing clearance. Sexual deterioration can be prevented.
[Brief description of the drawings]
FIG. 1 is a sectional view showing an embodiment of a pulley unit according to the present invention.
FIG. 2 is an enlarged cross-sectional view of a main part of another embodiment of the present invention, in which (a) is a cross-sectional view in an assembled state, and (b) to (d) are further main parts showing the process of the assembly. It is sectional drawing which expands and shows.
FIG. 3 is an enlarged cross-sectional view of a main part of still another embodiment of the present invention, (a) is a cross-sectional view in an assembled state, and (b) to (d) are further important views showing the process of the assembly. It is sectional drawing which expands and shows a part.
FIG. 4 is a cross-sectional view of still another embodiment of the present invention.
FIG. 5 is a cross-sectional view of still another embodiment of the present invention.
FIG. 6 is a cross-sectional view of a conventional pulley unit.
FIG. 7 is an enlarged cross-sectional view of a main part of a conventional pulley unit.
[Explanation of symbols]
1 Pulley member
2 Sleeve member
3, 4 Support bearing
5 outer ring
6 inner ring
14 Pulley side C-type retaining ring
18 steps
20 Pulley unit
21 Pulley member side retaining ring fixing part
22 Sleeve member side retaining ring fixing part
23 Pulley side retaining ring fixing part
24 Sleeve side retaining ring fixing part
33 C-type retaining ring on sleeve side
37 Belt groove
38 One-way roller clutch

Claims

A roller clutch in which a bearing ring having a cam surface and the other bearing ring having a cylindrical surface are concentrically disposed between a pulley and a sleeve, and a plurality of needle rollers are disposed therebetween,
In order to support free rotation of the roller clutch, a pulley unit comprising a support bearing press-fitted between the pulley and the sleeve from the pulley unit end face side,
A retaining ring groove is formed at a position on the pulley inner peripheral surface or the sleeve outer peripheral surface that coincides with the side surface on the pulley unit end surface side of the support bearing,
A pulley unit comprising a C-shaped retaining ring that expands in the retaining ring groove and prevents an outer ring from dropping from the pulley or an inner ring from the sleeve.