JP3774055B2

JP3774055B2 - Tapered roller bearing

Info

Publication number: JP3774055B2
Application number: JP00582398A
Authority: JP
Inventors: 和文中川; 一巳安達; 一徳浦上; 晃次増岡; 崇辻本
Original assignee: NTN Corp
Current assignee: NTN Corp
Priority date: 1997-11-21
Filing date: 1998-01-14
Publication date: 2006-05-10
Anticipated expiration: 2018-01-14
Also published as: JPH11210761A

Description

【０００１】
【発明の属する技術分野】
本発明は、自動車のデファレンシャル、トランスミッション等に組み込まれる円すいころ軸受に関する
【０００２】
【従来の技術】
円すいころ軸受は、ラジアル荷重とアキシャル荷重、およびそれらの合成荷重を負荷するのに適した軸受で、負荷能力も大きい。そのため、自動車や建設機械の動力伝達装置（デファレンシャル、トランスミッション）等における回転要素の支持用に多く用いられている。
【０００３】
図６は、円すいころ軸受の一形態を例示している。この円すいころ軸受は、円すい状の軌道面１１ａを有する外輪１１と、円すい状の軌道面１２ａを有し、この軌道面１２ａの小径側に小鍔面１２ｂ、大径側に大鍔面１２ｃを有する内輪１２と、外輪１１の軌道面１１ａと内輪１２の軌道面１２ａとの間に転動自在に配された複数の円すいころ１３と、円すいころ１３を円周所定間隔に保持する保持器１４とを備えている。
【０００４】
軸受使用時、円すいころ１３は軌道面１１ａおよび軌道面１２ａから受ける合成力によって内輪１２の大鍔面１２ｃに押し付けられ、その大端面１３ａを大鍔面１２ｃによって接触案内されながら軌道面上を転がり運動する。一方、軸受使用時、円すいころ１３の小端面１３ｂと内輪１２の小鍔面１２ｂとは接触せず、両者の間には僅かな隙間が存在する。そのため、軸受製造工程において、内輪１２の鍔面および円すいころ１３の端面は、滑り接触が生じる大鍔面１２ｃと大端面１３ａについてのみ摩耗低減等を目的として研削仕上げを施し、滑り接触が生じない小鍔面１２ｂと小端面１３ｂについては研削仕上げを行っていない。
【０００５】
上記のような円すいころ軸受を、保持器１４、複数の円すいころ１３、及び内輪１２からなる組付体を、内輪１２の小鍔面１２ｂ側を下に向けた状態で外輪１１の軌道面１１ａに上方から挿入して組立てた場合、組立時の状態（初期状態）において、円すいころ１３は軌道面上の正規の位置に座らず（保持器１４、内輪１２に対する自由度により、挿入時の円すいころ１３の姿勢が定まらないため）、図７（ａ）に示すように、その小端面１３ｂが内輪１２の小鍔面１２ｂに接触し、大端面１３ａと大鍔面１２ｃとの間に隙間δができた状態になる。この初期状態から、スラスト荷重Ｆａを作用させた状態で、軸受を所要回数回転させると｛図７（ｃ）｝、円すいころ１３が大鍔面１２ｃ側に隙間δ分だけ軸方向移動して、大端面１３ａが大鍔面１２ｃに接触し、円すいころ１３が正規の位置に落ち着く｛図７（ｂ）｝。
【０００６】
【発明が解決しようとする課題】
図７（ａ）に示す初期状態で軸受を相手装置の装着部位に固定し予圧を設定して本運転を行うと、円すいころ１３の大鍔面１２ｃ側への軸方向移動によって予圧抜けが生じ、要求される軸受機能が得られなくなる。そこで、従来より、本運転に先立って、図７（ａ）に示す初期状態の軸受を相手装置の装着部位に仮組付けし、円すいころ１３が図７（ｂ）に示す正規の位置に落ち着くまで馴らし運転を行った後、軸受を装着部位に固定し所定の予圧を付与するようにしている。この場合、初期状態における隙間δの大きさ及びばらつきの範囲が大きいと、円すいころ１３が正規の位置に落ち着くまでの馴らし運転時間が多く必要となり、予圧設定完了までの所要時間が長くなる。
【０００７】
従って、馴らし運転時間の短縮化の観点から、図７（ａ）に示す初期状態の隙間δの大きさ及びばらつき範囲は可及的に小さくすることが望ましいが、従来の円すいころ軸受では以下の点が問題となる。
【０００８】
図８に拡大して示すように、従来の円すいころ軸受における内輪１２の小鍔面１２ｂは、軌道面１２ａに配された円すいころ３の小端面１３ｂに対して外側に傾斜した形状になっており、そのため、小端面１３ｂ側の面取り寸法・形状のばらつきによって（一般に円すいころの小端面は鍛造面のままであり、面取り寸法・形状のばらつきが大きい。この面取り寸法・形状のばらつきは、円すいころ相互間に存在する他、円すいころ自体の円周方向にも存在する。）、組立時の状態（初期状態）における小端面１３ｂと小鍔面１２ｂとの接触点が変動する。例えば、小端面１３ｂ側の面取りが同図で実線で示すものであった場合、初期状態における接触点はＰ３、Ｐ４であるが、小端面１３ｂ側の面取りが同図で点線で示すものであった場合、初期状態における接触点は外径側に移動してＰ３’、Ｐ４’になる。円すいころ１３を大端面側に軸方向移動させて、大端面を大鍔面に接触させた時の、点Ｐ３・Ｐ４間の隙間の値をδ３、点Ｐ３’・Ｐ４’間の隙間の値をδ４とすると、δ３＜δ４となり、面取り寸法のばらつきに起因した接触点の変動に伴って隙間δの値が変動する。そのため、隙間δを精度良く規制することが困難である。
【０００９】
また、小端面１３ｂ側の面取り寸法・形状のばらつきによって、隙間δの値が変動するので、内輪１２の溝幅寸法（Ｗ’）および円すいころの長さ寸法（Ｌ’）を精度良く管理したとしても、隙間δのばらつきが不可避的に大きくなる。
【００１０】
円すいころの小端面側の面取り寸法・形状のばらつきに起因した隙間δの変動（ばらつき）は、ある１つの円すいころ軸受についてみた場合、組み込まれた複数の円すいころ相互間に生じ、各円すいころが正規の位置に落ち着くまでの時間差をもたらす。そのため、軸受として落ち着き状態になるまでの馴らし運転回数（軸受の回転回数：落ち着き回数）が多くなる。また、隙間δのばらつきが軸受相互間にも存在するので、軸受ごとに落ち着き回数のばらつきが生じる。この問題を、溝幅寸法（Ｗ’）および長さ寸法（Ｌ’）の管理幅（寸法公差）の縮小、隙間δの大きさの基準値の縮小によって対応しようとすると、加工コストおよび管理コストの増大につながる。
【００１１】
さらに、通常、内輪１２の溝幅寸法（Ｗ’）の管理は端面を寸法基準として行っているが、誤差が積算されやすく、溝幅寸法（Ｗ’）のばらつきを小さくすることが困難であった。この問題を解消するために、小鍔面１２ｂを寸法基準として溝幅寸法（Ｗ’）を管理することが考えられる。しかし、従来の小鍔面１２ｂは傾斜形状であり、基準位置のとり方によって溝幅寸法（Ｗ’）に差異が生じるため、溝幅寸法（Ｗ’）を精度良く仕上げることは困難である。
【００１２】
本発明は、上述した従来技術上の問題点に鑑み、コスト性を考慮しつつ、この種の円すいころ軸受における馴らし運転時間を短縮し、予圧設定作業の効率化を図ることを目的とする。
【００１３】
【課題を解決するための手段】
上記目的を達成するため、本発明では、円すい状の軌道面を有する外輪と、円すい状の軌道面を有し、この軌道面の小径側に小鍔面、大径側に大鍔面を有する内輪と、外輪の軌道面と内輪の軌道面との間に転動自在に配された複数の円すいころと、円すいころを円周所定間隔に保持する保持器とを備え、軸受使用時、円すいころの大端面が内輪の大鍔面によって接触案内される円すいころ軸受において、内輪の小鍔面を、この内輪の軌道面に配された円すいころの小端面と平行な面で、かつ、この円すいころの軸方向移動範囲を画する内輪の溝幅の一端を規定する面にした。
【００１４】
図５に拡大して示すように、内輪２の小鍔面２ｂを、軌道面２ａに配された円すいころ３の小端面３ｂと平行な面にすることによって、隙間δに対する小端面３ｂ側の面取り寸法・形状のばらつきの影響を排除することができる。例えば、小端面３ｂ側の面取りが同図で実線で示すものであった場合、組立時の状態（初期状態）における接触点はＰ５、Ｐ６であり、小端面３ｂ側の面取りが同図で点線で示すものであった場合、初期状態における接触点は外径側に移動してＰ５’、Ｐ６’になる。円すいころ３を大端面側に軸方向移動させて、大端面を大鍔面に接触させた時の、点Ｐ５・Ｐ６間の隙間の値をδ５、点Ｐ５’・Ｐ６’間の隙間の値をδ６とすると、小鍔面２ｂと小端面３ｂとが平行であるため、δ５＝δ６となり、接触点が変動しても隙間δの値は変動しない。従って、小端面３ｂ側の面取り寸法・形状のばらつきに起因した隙間δのばらつきがなくなる。
【００１５】
ある１つの円すいころ軸受についてみた場合、組み込まれた複数の円すいころ相互間に、小端面側の面取り寸法・形状のばらつきに起因した隙間δのばらつきがなくなるので、各円すいころが正規の位置に落ち着くまでの時間差が短縮される。そのため、軸受として落ち着き状態になるまでの馴らし運転回数（軸受の回転回数：落ち着き回数）が少なくなる。また、軸受ごとの落ち着き回数のばらつきも抑制される。
【００１６】
また、上記のような形状の小鍔面を寸法基準として大鍔面を仕上げ加工することにより、小鍔面から大鍔面までの溝幅寸法（Ｗ）を精度良く管理することができる。
【００１７】
上記のような形状の小鍔面は、円すいころの軸方向移動範囲を画する内輪の溝幅の一端を規定する面であり、かつ、隙間δの管理、溝幅寸法（Ｗ）の管理の基準となるため、精度確保のため、研削加工面とするのが望ましいが、所要の精度が確保できれば、コスト低減のため、旋削加工面としても良い。
【００１８】
円すいころを内輪の軌道面に配し、円すいころの大端面を内輪の大鍔面に接触させた時の、内輪の小鍔面と円すいころの小端面との間の隙間δをδ≦０．４ｍｍの寸法範囲内に規制することができる。δ≦０．４ｍｍとは、隙間δの最大値が０．４ｍｍを超えないという意味である。δ≦０．４ｍｍとしたのは以下の理由による。
【００１９】
内輪と円すいころとのマッチングにより、図７（ａ）に示す初期状態の隙間δがδ＞０．５ｍｍ（内輪の小鍔面が円すいころの小端面に対して外側に傾斜した形状の円すいころ軸受）、δ≦０．４５ｍｍ（内輪の小鍔面が円すいころの小端面と平行な形状の円すいころ軸受）となるように円すいころ軸受を組立て、図７（ａ）に示す初期状態から図７（ｂ）に示す状態に落ち着くまでの馴らし運転回数（軸受の回転回数：落ち着き回数）を求めたところ、下記に示す結果が得られた。
【００２０】

上記のように、δ≦０．４５ｍｍの場合に落ち着き回数が少なくなり良好な結果が得られた。特に、δ≦０．４ｍｍの場合では、落ち着き回数が少なく、かつ、ばらつきも小さくなる傾向が認められた。そこで、本発明では、より好ましい範囲としてδ≦０．４ｍｍを選択した。
【００２１】
【発明の実施の形態】
以下、本発明の実施形態について説明する。
【００２２】
図１に示すように、この実施形態の円すいころ軸受は、円すい状の軌道面１ａを有する外輪１と、円すい状の軌道面２ａを有し、この軌道面２ａの小径側に小鍔面２ｂ、大径側に大鍔面２ｃを有する内輪２と、外輪１の軌道面１ａと内輪２の軌道面２ａとの間に転動自在に配された複数の円すいころ３と、円すいころ３を円周所定間隔に保持する保持器４とで構成される。軸受使用時、円すいころ３は軌道面１ａおよび軌道面２ａから受ける合成力によって内輪２の大鍔面２ｃに押し付けられ、その大端面３ａを大鍔面２ｃによって接触案内されながら軌道面上を転がり運動する。軸受使用時、円すいころ３の小端面３ｂと内輪２の小鍔面２ｂとは接触せず、両者の間には僅かな隙間が存在する。
【００２３】
図２は、内輪２を示している。内輪２は、鋼素材から鍛造→旋削→熱処理→研削という工程を経て製造される。通常、研削加工は、端面、内径面、軌道面２ａ、および大鍔面２ｃに対して行われるが、この実施形態では、小鍔面２ｂを同図で鎖線で示す（軌道面２ａに配された）円すいころ３の小端面３ｂと略平行になるように旋削加工し、さらに、研削加工を施して小端面３ｂと平行になる面に仕上げている。尚、所要の精度が確保できれば、小鍔面２ｂを旋削加工によって、小端面３ｂと平行になる面に仕上げても良い。
【００２４】
大鍔面２ｃは、例えば上記のような小鍔面２ｂを寸法基準として、小鍔面２ｂからの溝幅寸法（Ｗ）をインプロセスゲージで測定しながら、研削加工によって仕上げることができる。これにより、溝幅寸法（Ｗ）を、狙い寸法に対して所定の寸法公差内に精度良く仕上げることができる。一般に、インプロセスゲージによる研削加工とは、研削加工時にゲージを当て、このゲージにより研削完了寸法を検出して、研削を終了する加工である。
【００２５】
内輪２の溝幅寸法（Ｗ）は、小鍔面２ｂと、大鍔面２ｃにおける円すいころ３の大端面３ａとの接触位置Ｐとの間の寸法（円すいころ３の軸線と平行な方向の寸法）であり、小鍔面２ｂは溝幅の一端を規定する面になる。
【００２６】
図３に示すように、円すいころ３は、曲率（端面アール：図面では誇張して示している。）をもった大端面３ａを一端に有し、曲率をもたないフラットな小端面３ｂを他端に有する。大端面３ａの中心領域には、ぬすみ部３ａ１が設けられている。大端面３ａ（ぬすみ部３ａ１を除く。）および転動面３ｃは研削加工によって仕上げられるが、通常、小端面３ｂは鍛造面のままである。円すいころ３の長さ寸法（Ｌ）は、狙い寸法に対して所定の寸法公差内に仕上げられる。尚、長さ寸法（Ｌ）は、小端面３ｂと、大端面３ａにおける大鍔面２ｃとの接触位置Ｐとの間の寸法（円すいころ３の軸線と平行な方向の寸法）である。
【００２７】
この実施形態の円すいころ軸受を、従来軸受と同様に、保持器４、複数の円すいころ３、及び内輪２からなる組付体を、内輪２の小鍔面２ｂ側を下に向けた状態で外輪１の軌道面１ａに上方から挿入して組立てた場合、組立時において、円すいころ３は軌道面上の正規の位置に座らず、その小端面３ｂが内輪２の小鍔面２ｂに接触し、大端面３ａと大鍔面２ｃとの間に隙間δができた状態になる。この初期状態から、スラスト荷重を作用させた状態で、軸受を所要回数回転させると、円すいころ３が大鍔面２ｃ側に隙間δ分だけ軸方向移動して、図１に示すように、大端面３ａが大鍔面２ｃに接触し、円すいころ３が正規の位置に落ち着く。
【００２８】
前述したように、図１に示す状態に落ち着くまでの馴らし運転回数（軸受の回転回数：落ち着き回数）を短縮するためには、上記隙間δ（円すいころ３の軸方向移動距離）のばらつきの範囲を可及的に小さくすることが望ましい。この実施形態では、内輪２の溝幅寸法（Ｗ）と円すいころ３の長さ寸法（Ｌ）を所定の寸法公差内に仕上げると共に、内輪２の小鍔面２ｂを円すいころ３の小端面３ｂと平行な面に加工し、かつ、円すいころ３を内輪２の軌道面２ａに配し、大端面３ａを大鍔面２ｃに接触させた時の、小鍔面２ｂと小端面３ｂとの間の隙間δを測定することにより、隙間δの値がδ≦０．４ｍｍの寸法範囲内に入るように規制している。そのため、馴らし運転回数（落ち着き回数）が、前述した測定結果の４回以内（平均２．９６回）を確実にクリアーでき、馴らし運転を比較的短時間で完了することができる。また、溝幅寸法（Ｗ）および長さ寸法（Ｌ）の管理幅（寸法公差）、隙間δの大きさの基準値を、許容範囲内で大きく設定することが可能であるので、加工コストおよび管理コストの低減の点で有利である。
【００２９】
【発明の効果】
本発明によれば、円すいころの小端面側の面取り寸法・形状のばらつきに起因した隙間δのばらつき要因がなくなり、隙間δの大きさの基準値を許容範囲内で大きく設定しても、隙間δ自体のばらつきが小さくなるので、馴らし運転時における円すいころの落ち着き状態が短時間で得られ、この種の円すいころ軸受における馴らし運転時間を短縮し、予圧設定作業の効率化を図ることができる。また、内輪の溝幅寸法および円すいころの長さ寸法の管理幅（寸法公差）、隙間δの大きさの基準値を許容範囲内で大きく設定した場合でも良好な結果が得られるので、加工コストおよび管理コストの低減の点で有利である。
【図面の簡単な説明】
【図１】実施形態の円すいころ軸受を示す断面図である。
【図２】図１に示す円すいころ軸受の内輪を示す断面図である。
【図３】図１に示す円すいころ軸受の円すいころを示す断面図である。
【図４】隙間δの測定時の状態を示す断面図である。
【図５】図４におけるＡ部の拡大断面図である。
【図６】従来の円すいころ軸受を示す断面図である。
【図７】従来の円すいころ軸受における組立時の状態（初期状態）を示す断面図（図ａ）、馴らし運転後の状態を示す断面図（図ｂ）、馴らし運転時の状態を示す断面図（図ｃ）である。
【図８】従来の円すいころ軸受における、小鍔面と小端面の周辺部を示す部分拡大断面図である。
【符号の説明】
１外輪
１ａ軌道面
２内輪
２ａ軌道面
２ｂ小鍔面
２ｃ大鍔面
３円すいころ
３ａ大端面
３ｂ小端面[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tapered roller bearing incorporated in an automobile differential, transmission or the like.
[Prior art]
Tapered roller bearings are suitable for carrying radial loads, axial loads, and their combined loads, and have a large load capacity. Therefore, it is often used for supporting rotating elements in power transmission devices (differential, transmission) of automobiles and construction machines.
[0003]
FIG. 6 illustrates an example of a tapered roller bearing. This tapered roller bearing has an outer ring 11 having a conical raceway surface 11a, a conical raceway surface 12a, and a small flange surface 12b on the small diameter side of the raceway surface 12a and a large flange surface 12c on the large diameter side. An inner ring 12 having a plurality of tapered rollers 13 which are rotatably arranged between the raceway surface 11a of the outer ring 11 and the raceway surface 12a of the inner ring 12, and a retainer 14 which holds the tapered rollers 13 at a predetermined circumferential interval. And.
[0004]
When the bearing is used, the tapered roller 13 is pressed against the large collar surface 12c of the inner ring 12 by a combined force received from the raceway surface 11a and the raceway surface 12a, and rolls on the raceway surface while the large end surface 13a is contacted and guided by the large collar surface 12c. Exercise. On the other hand, when the bearing is used, the small end surface 13b of the tapered roller 13 and the small flange surface 12b of the inner ring 12 are not in contact with each other, and there is a slight gap therebetween. Therefore, in the bearing manufacturing process, the flange surface of the inner ring 12 and the end surface of the tapered roller 13 are subjected to a grinding finish only for the large flange surface 12c and the large end surface 13a where the sliding contact occurs, and the sliding contact does not occur. The small surface 12b and the small end surface 13b are not ground.
[0005]
The tapered roller bearing as described above is assembled with the cage 14, the plurality of tapered rollers 13, and the inner ring 12, and the raceway surface 11a of the outer ring 11 with the small collar surface 12b side of the inner ring 12 facing downward. In the assembled state (initial state), the tapered roller 13 does not sit at a proper position on the raceway surface (the conical shape at the time of insertion depends on the degree of freedom with respect to the cage 14 and the inner ring 12). 7 (a), the small end surface 13b contacts the small collar surface 12b of the inner ring 12, and a gap δ is formed between the large end surface 13a and the large collar surface 12c. Will be ready. When the bearing is rotated a required number of times with the thrust load Fa applied from this initial state {FIG. 7 (c)}, the tapered roller 13 moves axially toward the large flange surface 12c by the gap δ, The large end surface 13a comes into contact with the large flange surface 12c, and the tapered roller 13 settles at a normal position {FIG. 7 (b)}.
[0006]
[Problems to be solved by the invention]
In the initial state shown in FIG. 7A, when the bearing is fixed to the mounting portion of the counterpart device and the preload is set and the main operation is performed, the preload loss occurs due to the axial movement of the tapered roller 13 toward the large flange surface 12c. The required bearing function cannot be obtained. Therefore, conventionally, prior to the actual operation, the bearing in the initial state shown in FIG. 7A is temporarily assembled to the mounting portion of the counterpart device, and the tapered roller 13 settles at the normal position shown in FIG. 7B. After the acclimation operation is performed, the bearing is fixed to the mounting site and a predetermined preload is applied. In this case, if the size of the gap δ and the range of variation in the initial state are large, a lot of habituation operation time is required until the tapered roller 13 settles at the normal position, and the time required for completion of the preload setting becomes long.
[0007]
Therefore, from the viewpoint of shortening the operating time, it is desirable to reduce the size and variation range of the initial gap δ shown in FIG. 7A as much as possible. However, in the conventional tapered roller bearing, The point becomes a problem.
[0008]
As shown in FIG. 8 in an enlarged manner, the small flange surface 12b of the inner ring 12 in the conventional tapered roller bearing has a shape inclined outward with respect to the small end surface 13b of the tapered roller 3 disposed on the raceway surface 12a. Therefore, due to variations in chamfer dimensions and shapes on the small end surface 13b side (generally, the small end surfaces of tapered rollers remain forged surfaces, and there are large variations in chamfer dimensions and shapes. The variations in chamfer dimensions and shapes are conical. In addition to existing between the rollers, it also exists in the circumferential direction of the tapered roller itself.) The contact point between the small end surface 13b and the small collar surface 12b in the assembled state (initial state) varies. For example, when the chamfer on the small end surface 13b side is shown by a solid line in the figure, the contact points in the initial state are P3 and P4, but the chamfer on the small end surface 13b side is shown by a dotted line in the figure. In this case, the contact point in the initial state moves to the outer diameter side to become P3 ′ and P4 ′. When the tapered roller 13 is moved in the axial direction toward the large end surface and the large end surface is brought into contact with the large flange surface, the value of the clearance between the points P3 and P4 is δ3, and the value of the clearance between the points P3 ′ and P4 ′ If δ4, then δ3 <δ4, and the value of the gap δ varies with the variation of the contact point due to the variation in the chamfer dimension. Therefore, it is difficult to accurately regulate the gap δ.
[0009]
In addition, since the value of the gap δ fluctuates due to variations in the chamfer dimension and shape on the small end face 13b side, the groove width dimension (W ′) of the inner ring 12 and the length dimension (L ′) of the tapered roller are accurately controlled. However, the variation of the gap δ is inevitably increased.
[0010]
Variation (variation) in the clearance δ due to variations in chamfer dimensions and shapes on the small end face side of tapered rollers occurs between a plurality of incorporated tapered rollers when viewed from a single tapered roller bearing. This will cause a time difference until it settles in the normal position. Therefore, the number of habituation operations (the number of rotations of the bearing: the number of times of calming) until the bearing becomes settled increases. In addition, since there is a variation in the gap δ between the bearings, a variation in the number of calms occurs for each bearing. If it is attempted to deal with this problem by reducing the control width (dimensional tolerance) of the groove width dimension (W ′) and the length dimension (L ′) and reducing the reference value of the size of the gap δ, the processing cost and the management cost Leads to an increase in
[0011]
Further, the groove width dimension (W ′) of the inner ring 12 is normally managed with the end face as a dimension reference, but errors are likely to be integrated, and it is difficult to reduce the variation in the groove width dimension (W ′). It was. In order to solve this problem, it is conceivable to manage the groove width dimension (W ′) with the small flange surface 12b as a dimensional reference. However, the conventional facet 12b has an inclined shape, and the groove width dimension (W ′) varies depending on the reference position. Therefore, it is difficult to accurately finish the groove width dimension (W ′).
[0012]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems in the prior art, and aims to shorten the operating time for this type of tapered roller bearing and to improve the efficiency of preload setting work while considering cost.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has an outer ring having a conical raceway surface, a conical raceway surface, a small flange surface on the small diameter side of the raceway surface, and a large collar surface on the large diameter side. Provided with an inner ring, a plurality of tapered rollers rotatably arranged between the raceway surface of the outer ring and the raceway surface of the inner ring, and a cage for holding the tapered rollers at a predetermined circumferential interval. In a tapered roller bearing in which the large end surface of the roller is contact-guided by the large collar surface of the inner ring, the small collar surface of the inner ring is a surface parallel to the small end surface of the tapered roller disposed on the raceway surface of the inner ring, and this A surface defining one end of the groove width of the inner ring that defines the axial movement range of the tapered roller was used.
[0014]
As shown in FIG. 5 in an enlarged manner, the small collar surface 2b of the inner ring 2 is a surface parallel to the small end surface 3b of the tapered roller 3 disposed on the raceway surface 2a, so that the small end surface 3b side with respect to the gap δ is obtained. The influence of variations in chamfer dimensions and shapes can be eliminated. For example, when the chamfering on the small end surface 3b side is indicated by a solid line in the figure, the contact points in the assembled state (initial state) are P5 and P6, and the chamfering on the small end surface 3b side is the dotted line in the figure. In this case, the contact point in the initial state moves to the outer diameter side to become P5 ′ and P6 ′. When the tapered roller 3 is axially moved toward the large end surface and the large end surface is brought into contact with the large flange surface, the value of the clearance between the points P5 and P6 is δ5, and the value of the clearance between the points P5 ′ and P6 ′ When δ6 is set, since the small flange surface 2b and the small end surface 3b are parallel, δ5 = δ6, and the value of the gap δ does not change even if the contact point changes. Accordingly, the variation in the gap δ due to the variation in the chamfer dimension and shape on the small end surface 3b side is eliminated.
[0015]
When looking at a single tapered roller bearing, there is no gap δ variation due to variations in chamfer dimensions and shapes on the small end face side between multiple incorporated tapered rollers, so each tapered roller is in its normal position. Time difference to settle down is shortened. For this reason, the number of habituation operations (the number of rotations of the bearing: the number of times of calming) until the bearing becomes settled is reduced. In addition, variations in the number of times of settling for each bearing are suppressed.
[0016]
Further, by finishing the large rib surface with the small rib surface having the above shape as a dimensional standard, the groove width dimension (W) from the small rib surface to the large rib surface can be managed with high accuracy.
[0017]
The facet of the shape as described above is a surface that defines one end of the groove width of the inner ring that defines the axial movement range of the tapered roller, and management of the gap δ and management of the groove width dimension (W). Since it is a standard, it is desirable to use a ground surface for ensuring accuracy. However, if the required accuracy can be ensured, it may be a turning surface for cost reduction.
[0018]
When the tapered roller is disposed on the raceway surface of the inner ring and the large end surface of the tapered roller is brought into contact with the large collar surface of the inner ring, the gap δ between the small collar surface of the inner ring and the small end surface of the tapered roller is δ ≦ 0 It can be regulated within a dimension range of 4 mm. δ ≦ 0.4 mm means that the maximum value of the gap δ does not exceed 0.4 mm. The reason why δ ≦ 0.4 mm is set is as follows.
[0019]
By matching between the inner ring and the tapered roller, the gap δ in the initial state shown in FIG. 7A is δ> 0.5 mm (the tapered roller having a shape in which the face of the inner ring is inclined outward with respect to the small end surface of the tapered roller). The tapered roller bearing is assembled so that δ ≦ 0.45 mm (the tapered surface of the inner ring is parallel to the tapered end surface of the tapered roller), and the initial state shown in FIG. When the number of acclimatization operations (the number of rotations of the bearing: the number of times of calming) until the state shown in 7 (b) was settled was determined, the following results were obtained.
[0020]

As described above, when δ ≦ 0.45 mm, the number of times of settling was reduced, and good results were obtained. In particular, in the case of δ ≦ 0.4 mm, there was a tendency that the number of times of calming was small and the variation was small. Therefore, in the present invention, δ ≦ 0.4 mm is selected as a more preferable range.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0022]
As shown in FIG. 1, the tapered roller bearing of this embodiment has an outer ring 1 having a conical raceway surface 1a and a conical raceway surface 2a, and a small flange surface 2b on the small diameter side of the raceway surface 2a. An inner ring 2 having a large flange surface 2c on the large-diameter side, a plurality of tapered rollers 3 disposed so as to roll between a raceway surface 1a of the outer ring 1 and a raceway surface 2a of the inner ring 2, and a tapered roller 3 It is comprised with the holder | retainer 4 hold | maintained at predetermined intervals of the circumference. When the bearing is used, the tapered roller 3 is pressed against the large collar surface 2c of the inner ring 2 by the combined force received from the raceway surface 1a and the raceway surface 2a, and rolls on the raceway surface while the large end surface 3a is contacted and guided by the large collar surface 2c. Exercise. When the bearing is used, the small end surface 3b of the tapered roller 3 and the small flange surface 2b of the inner ring 2 are not in contact with each other, and a slight gap exists between them.
[0023]
FIG. 2 shows the inner ring 2. The inner ring 2 is manufactured from a steel material through a process of forging → turning → heat treatment → grinding. Usually, the grinding is performed on the end face, the inner diameter surface, the raceway surface 2a, and the large collar surface 2c. In this embodiment, the small collar surface 2b is indicated by a chain line in FIG. I) Turning so as to be substantially parallel to the small end surface 3b of the tapered roller 3, and further grinding to finish the surface parallel to the small end surface 3b. If the required accuracy can be ensured, the small surface 2b may be finished to a surface parallel to the small end surface 3b by turning.
[0024]
The large flange surface 2c can be finished by grinding while measuring the groove width dimension (W) from the small flange surface 2b with an in-process gauge with the small flange surface 2b as described above as a dimensional reference, for example. Thereby, the groove width dimension (W) can be accurately finished within a predetermined dimensional tolerance with respect to the target dimension. In general, grinding with an in-process gauge is a process in which a gauge is applied at the time of grinding, a grinding completion dimension is detected by this gauge, and grinding is finished.
[0025]
The groove width dimension (W) of the inner ring 2 is the dimension between the small collar surface 2b and the contact position P of the large collar surface 2c with the large end surface 3a of the tapered roller 3 (in the direction parallel to the axis of the tapered roller 3). ) And the facet 2b is a surface that defines one end of the groove width.
[0026]
As shown in FIG. 3, the tapered roller 3 has a large end face 3a having a curvature (end face R: exaggerated in the drawing) at one end, and a flat small end face 3b having no curvature. Have at the other end. In the center region of the large end surface 3a, a shading portion 3a1 is provided. The large end surface 3a (excluding the fillet portion 3a1) and the rolling surface 3c are finished by grinding, but the small end surface 3b is usually a forged surface. The length dimension (L) of the tapered roller 3 is finished within a predetermined dimensional tolerance with respect to the target dimension. The length dimension (L) is a dimension (a dimension in a direction parallel to the axis of the tapered roller 3) between the small end surface 3b and the contact position P between the large end surface 3a and the large flange surface 2c.
[0027]
In the tapered roller bearing of this embodiment, as in the conventional bearing, the assembly comprising the retainer 4, the plurality of tapered rollers 3, and the inner ring 2 is placed with the small collar surface 2b side of the inner ring 2 facing downward. When assembled by inserting into the raceway surface 1a of the outer ring 1 from above, the tapered roller 3 does not sit at a regular position on the raceway surface, and its small end surface 3b contacts the small flange surface 2b of the inner ring 2. Thus, a gap δ is formed between the large end surface 3a and the large collar surface 2c. When the bearing is rotated a required number of times in a state where a thrust load is applied from this initial state, the tapered roller 3 moves axially by the gap δ toward the large flange surface 2c, and as shown in FIG. The end surface 3a comes into contact with the large collar surface 2c, and the tapered roller 3 settles in a proper position.
[0028]
As described above, in order to reduce the number of acclimation operations until the state shown in FIG. 1 is settled (the number of rotations of the bearing: the number of times of calming), the range of variation in the gap δ (the axial movement distance of the tapered roller 3) It is desirable to reduce as much as possible. In this embodiment, the groove width dimension (W) of the inner ring 2 and the length dimension (L) of the tapered roller 3 are finished within a predetermined dimensional tolerance, and the small flange surface 2b of the inner ring 2 is made the small end face 3b of the tapered roller 3. Between the small flange surface 2b and the small end surface 3b when the tapered roller 3 is disposed on the raceway surface 2a of the inner ring 2 and the large end surface 3a is brought into contact with the large collar surface 2c. By measuring the gap δ, the value of the gap δ is regulated to fall within the dimension range of δ ≦ 0.4 mm. Therefore, the number of habituation operations (the number of times of calming down) can be reliably cleared within 4 times (average 2.96 times) of the measurement results described above, and the habituation operation can be completed in a relatively short time. In addition, since the control width (dimensional tolerance) of the groove width dimension (W) and length dimension (L) and the reference value of the size of the gap δ can be set large within an allowable range, the processing cost and This is advantageous in terms of reducing management costs.
[0029]
【The invention's effect】
According to the present invention, there are no variations in the gap δ due to variations in the chamfer dimensions and shapes on the small end face side of the tapered roller, and even if the reference value of the size of the gap δ is set within a permissible range, the gap Since the variation of δ itself is reduced, the tapered state of the tapered roller during the acclimation operation can be obtained in a short time, and the acclimation operation time of this type of tapered roller bearing can be shortened and the preload setting work can be made more efficient. . In addition, good results can be obtained even if the control width (dimension tolerance) of the groove width dimension of the inner ring and the length dimension of the tapered roller (size tolerance) and the standard value of the gap δ are set within the allowable range. This is advantageous in terms of reducing management costs.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a tapered roller bearing of an embodiment.
2 is a cross-sectional view showing an inner ring of the tapered roller bearing shown in FIG. 1. FIG.
3 is a cross-sectional view showing a tapered roller of the tapered roller bearing shown in FIG. 1. FIG.
FIG. 4 is a cross-sectional view showing a state when a gap δ is measured.
5 is an enlarged cross-sectional view of a portion A in FIG.
FIG. 6 is a cross-sectional view showing a conventional tapered roller bearing.
FIG. 7 is a cross-sectional view (FIG. A) showing a state (initial state) during assembly of a conventional tapered roller bearing, a cross-sectional view (FIG. B) showing a state after a conditioned operation, and a cross-sectional view showing a state during a conditioned operation. (Fig. C).
FIG. 8 is a partially enlarged cross-sectional view showing a peripheral portion of a small flange surface and a small end surface in a conventional tapered roller bearing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Outer ring 1a Raceway surface 2 Inner ring 2a Raceway surface 2b Small collar surface 2c Large collar surface 3 Tapered roller 3a Large end surface 3b Small end surface

Claims

An outer ring having a conical raceway surface, an inner ring having a conical raceway surface, a small flange surface on the small diameter side and a large collar surface on the large diameter side, a raceway surface of the outer ring, and a raceway of the inner ring It has a plurality of tapered rollers that are arranged so as to be able to roll between them, and a cage that holds the tapered rollers at a predetermined circumferential distance. When the bearing is used, the large end surface of the tapered roller is caused by the large collar surface of the inner ring. In tapered roller bearings that are contact-guided,
The small ring surface of the inner ring is a plane parallel to the small end surface of the tapered roller disposed on the raceway surface of the inner ring, and defines one end of the groove width of the inner ring that defines the axial movement range of the tapered roller. Tapered roller bearings characterized by having a surface to be used.

When the tapered roller is arranged on the raceway surface of the inner ring and the large end surface of the tapered roller is brought into contact with the large collar surface of the inner ring, the gap δ between the small collar surface of the inner ring and the small end surface of the tapered roller is δ ≦ The tapered roller bearing according to claim 1, wherein the tapered roller bearing is regulated within a dimensional range of 0.4 mm.

The tapered roller bearing according to claim 1 or 2, wherein the surface of the inner ring is a ground surface.

The tapered roller bearing according to claim 1 or 2, wherein the small collar surface of the inner ring is a turning surface.

A method of manufacturing an inner ring for a tapered roller bearing having a tapered raceway surface, a small flange surface on the small diameter side of the raceway surface, and a large flange surface on the large diameter side,
The small surface is processed into a surface parallel to the small end surface when a tapered roller is disposed on the raceway surface, and the groove width dimension (W) to the large surface is determined based on the small surface. A method for producing an inner ring for a tapered roller bearing, wherein the large collar surface is finished by grinding while measuring with an in-process gauge.

6. The method for manufacturing an inner ring for a tapered roller bearing according to claim 5, wherein a small flange surface of the inner ring is finished by grinding.

6. The method for manufacturing an inner ring for a tapered roller bearing according to claim 5, wherein a small flange surface of the inner ring is finished by turning.

An outer ring having a conical raceway surface, an inner ring having a conical raceway surface, a small flange surface on the small diameter side and a large collar surface on the large diameter side, a raceway surface of the outer ring, and a raceway of the inner ring It has a plurality of tapered rollers that are arranged so as to be able to roll between them, and a cage that holds the tapered rollers at a predetermined circumferential distance. When the bearing is used, the large end surface of the tapered roller is caused by the large collar surface of the inner ring. A method of manufacturing a tapered roller bearing to be contact-guided,
The small ring surface of the inner ring is machined into a surface that is parallel to the small end surface when a tapered roller is arranged on the raceway surface of the inner ring, and the groove width dimension to the large rib surface is measured using the small rib surface as a dimensional reference. While measuring (W) with an in-process gauge, the large collar surface is finished by grinding, and the length dimension (L) of the tapered roller is controlled within a predetermined dimensional tolerance, and the tapered roller is By measuring the gap δ between the small collar surface of the inner ring and the small edge surface of the tapered roller when the large end surface of the tapered roller is in contact with the large collar surface of the inner ring A method of manufacturing a tapered roller bearing, characterized in that δ is regulated within a dimensional range of δ ≦ 0.4 mm.

9. The method of manufacturing a tapered roller bearing according to claim 8, wherein the small flange surface of the inner ring is finished by grinding.

9. The method of manufacturing a tapered roller bearing according to claim 8, wherein a small flange surface of the inner ring is finished by turning.