JP2004116716A

JP2004116716A - Rolling bearing device

Info

Publication number: JP2004116716A
Application number: JP2002283226A
Authority: JP
Inventors: Nobuyuki Seo; 瀬尾　信之
Original assignee: Koyo Seiko Co Ltd
Current assignee: Koyo Seiko Co Ltd
Priority date: 2002-09-27
Filing date: 2002-09-27
Publication date: 2004-04-15
Anticipated expiration: 2022-09-27
Also published as: JP4239542B2

Abstract

<P>PROBLEM TO BE SOLVED: To solve such problems with a rolling bearing device that a large-scale production is required because a hub shaft is formed by hot forging, production accuracy is poor, the number of steps is increased because post-machinings such as turning are required, and production cost is increased. <P>SOLUTION: Because a shaft body 22 and a second inner ring member 9 are formed by cold forging, this rolling bearing device can be manufactured by small-scale inexpensive facility. Because the tilted end 20a of a tilted part 20 is positioned at a generally intermediate portion between a first inner ring member 8 and the second inner ring member 9 and because an axial distance between a vehicle outer side end face and a predicted caulked part is short, the cylindrical shaft part 23 of the shaft body 22 can be prevented from being deformed in caulking. The end faces of the first inner ring member 8 and the second inner ring member 9 at one route part 10 and the other route part 15 can be surely pressed against each other, and specified preloads can be surely imparted to both rows of balls 4 and 5. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、車輪転がり軸受装置に係り、特に車軸を支持するのに適した転がり軸受装置に関する。
【０００２】
【従来の技術】
従来の車軸用転がり軸受装置には、外輪部材と、この外輪部材に２列の玉を介して軸心回りに回転自在に支持されるハブ軸と、このハブ軸の端部外周面に嵌合される筒状の内輪部材とを備え、ハブ軸の端部を内輪部材に対してかしめることで所定量の予圧を付与するとともに、ハブ軸と内輪部材とを回転一体に取付けるようにしたものがある（例えば、特許文献１参照）。
【０００３】
以下、図６に基づいて、従動輪側の車軸の支持用に用いられる転がり軸受装置の概略構成を説明する。この転がり軸受装置は、外輪部材５０と、複数の玉５１ａ，５１ｂと、内輪部材５２とを有する。外輪部材５０は、その内周面に軸方向２列で玉５１ａ，５１ｂ用の軌道面を有し車体側に非回転に支持される。内輪部材５２は、外周面に一方の玉５１ａの軌道面を有するハブ軸５３と、外周面に他方の玉５１ｂの軌道面を有し、かつハブ軸５３に外嵌される環状部材５４とを含むもので、外輪部材５０に対して径方向内側で同心に配置される。
【０００４】
ハブ軸５３は、熱間鍛造によって中実断面に形成されるものであり、軸部５５と、ハブフランジ５６と、環状ガイド部５７とを備える。ハブフランジ５６は、ブレーキディスクおよびタイヤホイールを重ねて取付けるため、軸部５５の車両アウタ側外周面の径方向外向きに形成されている。環状ガイド部５７は、インロー部とも称され、ハブフランジ５６に対して車両アウタ側に突出して形成される。この環状ガイド部５７は、ブレーキディスクおよびタイヤホイールをハブフランジ５６に重ねる際のガイドとなる。
【０００５】
【特許文献１】
特開２０００−３８００４号（第３頁，第１図）
【０００６】
【発明が解決しようとする課題】
上記転がり軸受装置のハブ軸５３では、熱間鍛造によって異なった三方向に張出す各部５５〜５７を一体に形成するために、大圧力を加えるためのプレス機など高価で大掛かりな製造設備が必要となる。特に熱間鍛造の場合、ハブ軸５３の製品精度を所要以上に確保しにくいために、鍛造後にハブ軸５３に対する旋削や研磨などの後加工が必要とされ製造工程数が増加し、製造コストも高くなる、などの不具合が指摘される。
【０００７】
【課題を解決するための手段】
本発明の転がり軸受装置は、外輪部材と、前記外輪部材と同心に配置される内輪部材と、前記両部材間に転動自在に介装される複列の転動体とを含み、前記内輪部材は、軸方向一方側に配置されて一方列の転動体の内輪軌道面を有するとともに、ブレーキディスク取付け用のフランジを有する第一の内輪部材と、前記第一の内輪部材に軸方向他方側で当接して隣合う第二の内輪部材とを備え、前記第二の内輪部材は、その外周面に他方列の内輪軌道面を有する軌道部と、この軌道部から縮径して前記第一の内輪部材の内周面に沿うように延長して嵌合される嵌合部とを含み、前記軌道部と嵌合部との連続部の内周面に、前記軌道部から嵌合部に縮径するのに伴なって段付面が形成され、前記嵌合部に軸方向一方側から内嵌挿通される軸体が設けられ、この軸体の軸方向他方側端部が前記段付面にかしめられ、該軸体の軸方向一方側端部に径方向外向きに拡径された拡径部が形成され、この拡径部の端面が前記フランジの端面に圧接されている。
【０００８】
上記構成のように、第一の内輪部材と第二の内輪部材とを軸心回りに回転一体とするためのかしめ部分を第一の内輪部材と第二の内輪部材との中間位置に位置させたことにより、内輪部材の軸方向端面に対してかしめる場合に比べて、かしめ受面からの軸方向距離が小さくなるため、軸体のかしめ予定部をかしめる際に軸体が変形（座屈）するのを抑えることができ、第一の内輪部材と第二の内輪部材の端面どうしを確実に圧接して、かつ転動体に対して所定の予圧が付与され、十分な剛性を有し安定した転がり軸受装置となる。
【０００９】
また、本発明の転がり軸受装置は、前記拡径部の外周面に、前記ブレーキディスクをフランジに重ねて取付ける際の案内面が形成されている。
【００１０】
このように、軸体の拡径部を、ブレーキディスクをフランジに重ねて取付ける際の案内面に兼用することにより、ブレーキディスクを案内するための部材を軸体とは別に設ける必要がないので、部品点数の増加を抑えることができる。
【００１１】
さらに上記のように、内輪部材を、フランジを有する第一の内輪部材と、これとは別体の第二の内輪部材とから構成したことにより、高価で大掛かりな製造設備が不要となるばかりでなく、場合によっては研磨加工あるいは旋削加工などの後加工時間が短縮もしくは省略可能となる。
【００１２】
【発明の実施の形態】
以下、本発明の実施形態に係る転がり軸受装置を、従動輪側に用いられる車軸用転がり軸受を例に、図面に基づいて説明する。図１は本発明の実施形態に係る転がり軸受装置の全体構成を示す断面図、図２は分解断面図、図３は転がり軸受装置の製造途中を示す一部拡大断面図、図４は転がり軸受装置の製造途中を示す全体断面図である。
【００１３】
図１および図２に示すように、この転がり軸受装置１は、外輪部材２と、この外輪部材２と同心に配置される内輪部材３と、保持器４ａ，５ａによって円周方向等配位置に保持された状態で外輪部材２および内輪部材３間に転動自在に介装される２列の玉４，５（転動体）とを有する。
【００１４】
外輪部材２は炭素鋼（例えばＪＩＳ規格Ｓ５５Ｃ）でもって熱間鍛造によって形成され、その内周面に各列の玉４，５の外輪軌道面が形成されている。外輪部材２の外周面に、径方向外向きに突出する取付けフランジ６が形成されている。この取付けフランジ６が、不図示の車体側に組込まれるナックルに取付けられることで、外輪部材２が車体に対して軸心回りに非回転に支持される。外輪部材２の車両インナ側端部に、不図示の車速センサーを内装する空間を確保するためのカバー７が嵌着されている。
【００１５】
内輪部材３は、軸方向一方側に配置される第一の内輪部材８と、この第一の内輪部材８に対して軸方向他方側に配置されるとともに、第一の内輪部材８に当接して隣合う第二の内輪部材９とから構成される。
【００１６】
第一の内輪部材８は炭素鋼（例えばＪＩＳ規格Ｓ５５Ｃ）でもって熱間鍛造によって形成され、一方列の玉４の内輪軌道面を有する円筒状の一方軌道部１０と、この一方軌道部１０の車両アウタ側部位で径方向外向きに突出形成されるブレーキディスク１１取付け用のハブフランジ１２を有する。このハブフランジ１２の円周方向等配位置に、ブレーキディスク１１およびホイール１３に形成された挿通孔１１ａ，１３ａに挿通するハブボルト１４が圧入されている。
【００１７】
第二の内輪部材９は、管状の素材（例えばＪＩＳ規格Ｓ５５Ｃからなる）から冷間鍛造によって形成される。この第二の内輪部材９は、他方列の玉５の内輪軌道面が形成された筒状の他方軌道部１５と、この他方軌道部１５から縮径して第一の内輪部材８の一方軌道部１０内周面に沿うように延長して形成される嵌合部１６とを有する。
【００１８】
一方軌道部１０の車両インナ側の端面１０ａと他方軌道部１５の車両アウタ側の端面１５ａとは、軸方向で当接している。他方軌道部１５と嵌合部１６との連続部に、他方軌道部１５から嵌合部１６に縮径するのに伴なう円錐環状の傾斜部２０が形成され、この傾斜部２０の内周面が傾斜段付面２１とされている。この傾斜部２０の傾斜端２０ａは、第一の内輪部材８の車両アウタ側端面と、第二の内輪部材９における車両インナ側端面のほぼ中間部位に位置している。
【００１９】
嵌合部１６に対して軸方向一方側、すなわち車両アウタ側から内嵌挿通される軸体２２が設けられている。この軸体２２は管状の素材（例えばＪＩＳ規格Ｓ５５Ｃからなる）から冷間鍛造によって形成される。軸体２２は、嵌合部１６に内嵌挿通して嵌着される円筒状軸部２３と、この円筒状軸部２３の車両アウタ側部位で径方向外向きに突出して形成された環状案内部（拡径部）２４とを有する。軸体２２の軸方向他方側端部の中心に、底有の凹部２２ａが形成されている。
【００２０】
この凹部２２ａが形成された部分は円筒形状となり、後述のかしめ部２６とされる部分である。なお、この凹部２２ａを軸方向に延長して、軸体２２に軸方向に貫通する穴を形成することにより、軸体２２を軽量化することができる。この場合、外部から穴を通じて軸受内部に水等が侵入するおそれあるので、当該穴を塞ぐためのキャップ等を軸体２２に設けるのが望ましい。
【００２１】
この環状案内部２４の中心部位に、車両インナ側に凹となる凹部２４ａが形成され、これにより、環状案内部２４の外周部位に、ブレーキディスク１１およびタイヤホイール１３をハブフランジ１２に対して重ねて取付けて案内する際に十分な軸方向長さを有した環状の案内面２５が形成されている。軸体２２における円筒状軸部２３の軸方向他方側端部が拡径されて、傾斜段付面２１に対してかしめられたかしめ部２６とされている。
【００２２】
すなわちかしめ予定部２６ａを拡径するようにして傾斜段付面２１に対してかしめることにより、環状案内部２４の車両インナ側端面が、前記ハブフランジ１２の端面に圧接されるとともに、第一の内輪部材８における一方軌道部１０および第二の内輪部材９における他方軌道部１５の端面１０ａ，１５ａどうしが軸方向で圧接され、両列の玉４，５に対して所定の予圧が付与された状態となる。
【００２３】
図中の符号２７はシール部材を示す。このシール部材２７は、外輪部材２の車両アウタ側端部内周面に嵌着され、外輪部材２と内輪部材３との間の環状空間内の潤滑剤が外部に漏れるのを防止するとともに、ハブフランジ１２と外輪部材２との間から環状空間内に泥水等が侵入するのを防止する機能を有する。
【００２４】
次に、上記構成における転がり軸受装置１の組立て方法を説明する。まず各列の玉４，５をそれぞれ保持器４ａ，５ａで円周方向等配位置に保持した組品とし、これら組品を外輪部材２の軸方向両側、すなわち車両インナ側（車両インナ側相当方向）および車両アウタ側（車両アウタ側相当方向）から外輪部材２内に挿入し、各列の玉４，５をそれぞれ外輪軌道面に接触させて保持しておく。
【００２５】
続いて、第一の内輪部材８の一方軌道部１０を外輪部材２の車両アウタ側から挿入し、一方列の玉４に一方軌道部１０の外周面に形成した内輪軌道面を当接させる。また第二の内輪部材９を外輪部材２の車両インナ側から挿入し、第二の内輪部材９の嵌合部１６を第一の内輪部材８の一方軌道部１０に内嵌するとともに、他方列の玉５に他方軌道部１５の外周面に形成した内輪軌道面を当接させる。このようにすることにより、第一の内輪部材８における一方軌道部１０および第二の内輪部材９における他方軌道部１５の端面１０ａ，１５ａどうしが軸方向で対向した状態となる。
【００２６】
ところで、一方列の玉４に一方軌道部１０の外周面に形成した内輪軌道面を当接させ、他方列の玉５を第二の内輪部材９の内輪軌道面に当接させた際、図３に示すように、端面１０ａ，１５ａどうしは圧接しないよう軌道面間の軸方向寸法、一方軌道部１０、他方軌道部１５の軸方向寸法等を設定しておく。
【００２７】
続いて、軸体２２における円筒状軸部２３を、車両アウタ側から第二の内輪部材９の嵌合部１６に内嵌挿通させ、環状案内部２４の車両インナ側端面をハブフランジ１２の端面に当てる。
【００２８】
このような状態を保持したまま、環状案内部２４の車両アウタ側端面、例えば図４に示すように、環状案内部２４の凹部２４ａにおける底面２４ｂを支持台３６に支持させる。そして、第二の内輪部材９の車両アウタ側からかしめ具３５を挿入して、その先端部を軸体２２の円筒状軸部２３の端部であるかしめ予定部２６ａの中心凹部２６ｂに挿入して、かしめ予定部２６ａを拡径するようにしてかしめ加工を行い、傾斜部２０の傾斜段付面２１に圧接させ、かしめ部２６を形成する。
【００２９】
こうすることにより、その際のかしめ力でもって環状案内部２４の車両インナ側端面がハブフランジ１２の端面に圧接し、第一の内輪部材８における一方軌道部１０および第二の内輪部材９における他方軌道部１５の端面１０ａ，１５ａどうしが軸方向で圧接されるとともに、両列の玉４，５に対して所定の予圧が付与される。
【００３０】
そして、傾斜部２０の傾斜端２０ａは、第一の内輪部材８の車両アウタ側端面と、第二の内輪部材９における車両インナ側端面のほぼ中間部位に位置しているので、車両アウタ側端面（環状案内部２４の凹部２４ａにおける底面２４ｂ）からかしめ予定部２６ａまでの軸方向距離が短い。従って軸体２２における円筒状軸部２３が、かしめ時に大きく変形してしまうという座屈現象を防止することができる。
【００３１】
以上のように、第一の内輪部材８における一方軌道部１０および第二の内輪部材９における他方軌道部１５の端面１０ａ，１５ａどうしを確実に軸方向で圧接させることができるとともに、両列の玉４，５に対して所定の予圧を確実に付与して、十分ば剛性を有し安定した転がり軸受装置１とすることができる。
【００３２】
上記のようにして転がり軸受装置１を組立てた後は、ブレーキディスク１１およびタイヤホイール１３を、これらの中心部に形成した中心穴を環状案内部２４の案内面２５で案内させてハブフランジ１２に対して重ねて取付ける。
【００３３】
そして上記構成の転がり軸受装置１は、車両が走行すると、不図示の車輪の回転とともに、第一の内輪部材８および第二の内輪部材９が軸体２２とともに軸心回りに回転する。
【００３４】
ところで、この転がり軸受装置１における軸体２２および第二の内輪部材９は、管状の素材を用いて冷間鍛造によって形成している。このため、従来例のように、ハブ軸を熱間鍛造によって中実断面に形成する場合に比べて、転がり軸受装置１の全体の容量および重量を低減させることができる。これにより、車両重量の低減（特に、ばね下重量の低減）が可能になる。
【００３５】
また従来例のように、ハブ軸を熱間鍛造によって中実断面に形成する場合に比べて、小規模で安価な製造設備であつても対応でき、しかも第二の内輪部材９を高精度に成形することができる。すなわち熱間鍛造の場合は製品の表面精度も低く、特に玉５の内輪軌道面を必要な精度とするための研磨加工時間を長く必要とし、場合によっては内輪軌道面以外の部分も研磨加工を必要としていた。これに対して、管状の素材を用い、冷間鍛造によって第二の内輪部材９を形成する場合は、材料コストも安価であり、また精度よく製造することができるので、内輪軌道面を必要な精度とするための研磨加工時間が短縮でき、内輪軌道面以外の部分の研磨加工をほとんど必要としない。これによって、製造コストを大幅に低減し得る。
【００３６】
図５は別の製造方法を示すもので、一方列の玉４と一方軌道部１０の内輪軌道面を当接させ、他方の玉５と他方軌道部１５の内輪軌道面とを当接させた時点で、図示のように、端面１０ａ，１５ａどうしが圧接し、両列の玉４，５に対して所定の予圧が付与されるよう軌道面間の軸方向寸法、一方軌道部１０、他方軌道部１５の軸方向寸法を設定しておく場合を示す。
【００３７】
そして、端面１０ａ，１５ａどうしが圧接し、両列の玉４，５に対して所定の予圧を付与した状態を保持して、第二の内輪部材９の車両アウタ側からかしめ具３５を挿入して、その先端部を軸体２２の円筒状軸部２３の端部であるかしめ予定部２６ａの中心凹部２６ｂに挿入して、これを拡径するようかしめ加工を行い、傾斜部２０の傾斜段付面２１に圧接させてかしめ部２６を形成する。
【００３８】
このように、予め端面１０ａ，１５ａどうしを圧接し、両列の玉４，５に対して所定の予圧を付与した状態を保持して傾斜部２０の傾斜段付面２１にかしめ予定部２６ａを変形させてかしめ、かしめ部２６を形成することによれば、かしめ時に玉４，５に対して不要な力が働くのを防止できるので、転がり軸受装置１の製造時に玉４，５に損傷（圧痕）を与えるのを防止することができる。あるいは、軌道面に損傷を与えるのを防止することができる。
【００３９】
【発明の効果】
以上の説明から明らかな通り、本発明によれば、軸体に座屈を発生させることなく第一の内輪部材と第二の内輪部材とを確実に一体化させることができるとともに転動体に対して予圧を付与することができる。さらに、高価で大掛かりな設備が不要となるばかりでなく、研磨加工あるいは旋削加工などの後加工時間を短縮もしくは省略でき、もって製造コストの低減を図り得る。
【図面の簡単な説明】
【図１】本発明の実施の形態に係る転がり軸受装置の全体構成を示す断面図である。
【図２】同じく分解斜視図である。
【図３】同じく製造途中の断面図である。
【図４】同じく転がり軸受装置の製造途中を示す全体断面図である。
【図５】本発明の実施の形態に係る転がり軸受装置の別の製造方法を示す要部拡大断面図である。
【図６】従来の転がり軸受装置の全体構成を示す断面図である。
【符号の説明】
１　　　転がり軸受装置
２　　　外輪部材
８　　　第一の内輪部材
９　　　第二の内輪部材
１０　　一方軌道部
１２　　ハブフランジ
１５　　他方軌道部
１６　　嵌合部
２０　　傾斜部
２１　　傾斜段付面
２２　　軸体
２４　　環状案内部
２６　　かしめ部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a wheel rolling bearing device, and more particularly to a rolling bearing device suitable for supporting an axle.
[0002]
[Prior art]
In a conventional axle rolling bearing device, an outer ring member, a hub shaft rotatably supported on the outer ring member through two rows of balls around an axis, and an outer peripheral surface of an end portion of the hub shaft are fitted. A cylindrical inner ring member is provided, and a predetermined amount of preload is applied by caulking an end portion of the hub axle to the inner ring member, and the hub axle and the inner ring member are attached to rotate integrally. (For example, see Patent Document 1).
[0003]
Hereinafter, a schematic configuration of the rolling bearing device used for supporting the axle on the driven wheel side will be described with reference to FIG. The rolling bearing device includes an outer ring member 50, a plurality of balls 51a and 51b, and an inner ring member 52. The outer race member 50 has a raceway surface for the balls 51a and 51b in two rows in the axial direction on its inner peripheral surface, and is supported non-rotatably on the vehicle body side. The inner ring member 52 includes a hub axle 53 having a raceway surface of one ball 51a on the outer peripheral surface, and an annular member 54 having a raceway surface of the other ball 51b on the outer peripheral surface and fitted externally to the hub shaft 53. And concentrically arranged radially inward with respect to the outer ring member 50.
[0004]
The hub shaft 53 is formed into a solid cross section by hot forging, and includes a shaft portion 55, a hub flange 56, and an annular guide portion 57. The hub flange 56 is formed radially outward of the outer peripheral surface of the shaft portion 55 on the vehicle outer side in order to mount the brake disk and the tire wheel in an overlapping manner. The annular guide portion 57 is also referred to as a spigot portion, and is formed to protrude toward the vehicle outer side with respect to the hub flange 56. The annular guide 57 serves as a guide when the brake disc and the tire wheel are overlapped on the hub flange 56.
[0005]
[Patent Document 1]
JP 2000-38004 A (Page 3, FIG. 1)
[0006]
[Problems to be solved by the invention]
In the hub axle 53 of the above-mentioned rolling bearing device, in order to integrally form the respective portions 55 to 57 projecting in three different directions by hot forging, expensive and large-scale manufacturing equipment such as a press machine for applying a large pressure is required. It becomes. Particularly, in the case of hot forging, since it is difficult to secure the product accuracy of the hub shaft 53 more than required, post-processing such as turning or polishing of the hub shaft 53 is required after forging, the number of manufacturing steps increases, and the manufacturing cost increases. It is pointed out that there is a problem such as an increase.
[0007]
[Means for Solving the Problems]
The rolling bearing device of the present invention includes an outer ring member, an inner ring member concentrically arranged with the outer ring member, and a double-row rolling element rotatably interposed between the two members, wherein the inner ring member A first inner ring member having an inner ring raceway surface of one row of rolling elements disposed on one side in the axial direction and having a flange for mounting a brake disc, and a first inner ring member on the other side in the axial direction. A second inner ring member that abuts and is adjacent to the first inner ring member, wherein the second inner ring member has a raceway portion having an inner raceway surface of the other row on the outer peripheral surface thereof, and the first inner raceway having a reduced diameter from the raceway portion. A fitting portion extending and fitted along the inner peripheral surface of the inner ring member; and reducing an inner peripheral surface of a continuous portion of the track portion and the fitting portion from the track portion to the fitting portion. A stepped surface is formed along with the diameter, and a shaft body is inserted into the fitting portion from one side in the axial direction. The other end in the axial direction of the shaft body is caulked to the stepped surface, and a radially enlarged portion is formed at one end in the axial direction of the shaft body so as to expand radially outward. The end face of the diameter portion is pressed against the end face of the flange.
[0008]
As in the above configuration, the swaging portion for integrally rotating the first inner ring member and the second inner ring member around the axis is located at an intermediate position between the first inner ring member and the second inner ring member. As a result, the axial distance from the caulking receiving surface is smaller than when caulking with respect to the axial end surface of the inner ring member. Bending) can be suppressed, and the end faces of the first inner ring member and the second inner ring member are reliably pressed against each other, and a predetermined preload is applied to the rolling element, and the rolling element has sufficient rigidity. A stable rolling bearing device is obtained.
[0009]
Further, in the rolling bearing device of the present invention, a guide surface is formed on an outer peripheral surface of the enlarged diameter portion when the brake disk is mounted on a flange.
[0010]
As described above, by using the enlarged diameter portion of the shaft as a guide surface when the brake disk is mounted on the flange so as to overlap with the flange, it is not necessary to provide a member for guiding the brake disk separately from the shaft. An increase in the number of parts can be suppressed.
[0011]
Further, as described above, the inner ring member is constituted by the first inner ring member having the flange and the second inner ring member which is separate from the inner ring member, so that expensive and large-scale manufacturing equipment is not required. In some cases, post-processing time such as polishing or turning may be reduced or omitted.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a rolling bearing device according to an embodiment of the present invention will be described with reference to the drawings, taking an axle rolling bearing used on a driven wheel side as an example. FIG. 1 is a cross-sectional view showing the overall configuration of a rolling bearing device according to an embodiment of the present invention, FIG. 2 is an exploded cross-sectional view, FIG. 3 is a partially enlarged cross-sectional view showing the rolling bearing device in the course of manufacture, and FIG. FIG. 3 is an overall cross-sectional view showing the device during manufacture.
[0013]
As shown in FIGS. 1 and 2, the rolling bearing device 1 is provided at an equidistant circumferential position by an outer ring member 2, an inner ring member 3 arranged concentrically with the outer ring member 2, and retainers 4 a and 5 a. It has two rows of balls 4 and 5 (rolling elements) rotatably interposed between the outer ring member 2 and the inner ring member 3 while being held.
[0014]
The outer race member 2 is formed by hot forging with carbon steel (for example, JIS S55C), and the outer raceway surfaces of the balls 4 and 5 in each row are formed on the inner peripheral surface thereof. A mounting flange 6 is formed on the outer peripheral surface of the outer race member 2 and protrudes radially outward. By attaching the mounting flange 6 to a knuckle incorporated into the vehicle body (not shown), the outer ring member 2 is supported non-rotatably around the axis with respect to the vehicle body. A cover 7 for securing a space for installing a vehicle speed sensor (not shown) is fitted to an end portion of the outer race member 2 on the vehicle inner side.
[0015]
The inner ring member 3 is disposed on one side in the axial direction, and is disposed on the other side in the axial direction with respect to the first inner ring member 8, and is in contact with the first inner ring member 8. And the second inner ring member 9 adjacent to the second inner ring member 9.
[0016]
The first inner race member 8 is formed by hot forging with carbon steel (for example, JIS standard S55C), and has a cylindrical one raceway portion 10 having an inner raceway surface of one row of balls 4, and one cylindrical raceway portion 10. It has a hub flange 12 for mounting a brake disk 11 that is formed so as to protrude radially outward at an outer portion of the vehicle. Hub bolts 14 that are inserted into insertion holes 11 a and 13 a formed in the brake disk 11 and the wheel 13 are press-fitted at circumferentially equal positions on the hub flange 12.
[0017]
The second inner ring member 9 is formed by cold forging from a tubular material (for example, made of JIS standard S55C). The second inner race member 9 has a cylindrical other raceway portion 15 on which the inner raceway surface of the other row of balls 5 is formed, and one raceway of the first inner race member 8 whose diameter is reduced from the other raceway portion 15. And a fitting portion 16 formed to extend along the inner peripheral surface of the portion 10.
[0018]
An end surface 10a on the vehicle inner side of the one track portion 10 and an end surface 15a on the vehicle outer side of the other track portion 15 abut in the axial direction. A conical annular inclined portion 20 is formed in a continuous portion between the other track portion 15 and the fitting portion 16 as the diameter decreases from the other track portion 15 to the fitting portion 16. The surface is an inclined stepped surface 21. The inclined end 20a of the inclined portion 20 is located at a substantially intermediate position between the vehicle outer end surface of the first inner race member 8 and the vehicle inner end surface of the second inner race member 9.
[0019]
A shaft body 22 is provided which is inserted into the fitting portion 16 from one side in the axial direction, that is, from the vehicle outer side. This shaft body 22 is formed by cold forging from a tubular material (for example, made of JIS standard S55C). The shaft body 22 includes a cylindrical shaft portion 23 that is fitted by being inserted into the fitting portion 16 and an annular guide formed so as to protrude radially outward at a vehicle outer side portion of the cylindrical shaft portion 23. (Enlarged portion) 24. A recess 22 a having a bottom is formed at the center of the other end in the axial direction of the shaft body 22.
[0020]
The portion where the concave portion 22a is formed has a cylindrical shape and is a portion to be a caulking portion 26 described later. The shaft body 22 can be reduced in weight by extending the recess 22a in the axial direction and forming a hole through the shaft body 22 in the axial direction. In this case, since water or the like may enter the inside of the bearing from the outside through the hole, it is desirable to provide a cap or the like for closing the hole on the shaft 22.
[0021]
A concave portion 24a that is concave toward the vehicle inner side is formed at a central portion of the annular guide portion 24, so that the brake disc 11 and the tire wheel 13 are superimposed on the hub flange 12 on the outer peripheral portion of the annular guide portion 24. An annular guide surface 25 having a sufficient axial length for mounting and guiding is formed. The other end in the axial direction of the cylindrical shaft portion 23 of the shaft body 22 is enlarged in diameter to form a caulked portion 26 caulked against the inclined stepped surface 21.
[0022]
In other words, by caulking the portion to be caulked 26 a against the inclined stepped surface 21 so as to expand the diameter, the inner side end surface of the annular guide portion 24 is pressed against the end surface of the hub flange 12, and The end faces 10a and 15a of the one raceway portion 10 of the inner race member 8 and the other raceway portion 15 of the second inner race member 9 are pressed against each other in the axial direction, and a predetermined preload is applied to the balls 4 and 5 in both rows. State.
[0023]
Reference numeral 27 in the drawing indicates a seal member. The seal member 27 is fitted to the inner peripheral surface of the outer ring member 2 at the vehicle outer side end to prevent the lubricant in the annular space between the outer ring member 2 and the inner ring member 3 from leaking to the outside, and to prevent the hub from rotating. It has a function of preventing muddy water or the like from entering the annular space from between the flange 12 and the outer ring member 2.
[0024]
Next, a method of assembling the rolling bearing device 1 having the above configuration will be described. First, the balls 4 and 5 in each row are assembled in the circumferential direction at equal positions by retainers 4a and 5a, respectively, and these assemblies are disposed on both axial sides of the outer ring member 2, that is, on the vehicle inner side (corresponding to the vehicle inner side). Direction) and the vehicle outer side (a direction corresponding to the vehicle outer side) is inserted into the outer race member 2, and the balls 4 and 5 in each row are held in contact with the outer raceway surface.
[0025]
Subsequently, the one raceway portion 10 of the first inner race member 8 is inserted from the vehicle outer side of the outer race member 2, and the inner raceway surface formed on the outer peripheral surface of the one raceway portion 10 is brought into contact with one row of balls 4. Further, the second inner ring member 9 is inserted from the vehicle inner side of the outer ring member 2, and the fitting portion 16 of the second inner ring member 9 is internally fitted to the one raceway portion 10 of the first inner ring member 8, and the other row The inner ring raceway surface formed on the outer peripheral surface of the other raceway portion 15 is brought into contact with the ball 5. By doing so, the end surfaces 10a and 15a of the one raceway portion 10 of the first inner race member 8 and the other raceway portion 15 of the second inner race member 9 are in a state of being opposed in the axial direction.
[0026]
Incidentally, when the inner raceway surface formed on the outer peripheral surface of the one raceway portion 10 is brought into contact with the balls 4 in one row, and the balls 5 in the other row are brought into contact with the inner raceway surface of the second inner race member 9, FIG. As shown in FIG. 3, the axial dimensions between the raceway surfaces, the axial dimensions of the one raceway section 10 and the other raceway section 15 and the like are set so that the end faces 10a and 15a do not press against each other.
[0027]
Subsequently, the cylindrical shaft portion 23 of the shaft body 22 is inserted into the fitting portion 16 of the second inner race member 9 from the vehicle outer side, and the vehicle inner side end surface of the annular guide portion 24 is connected to the end surface of the hub flange 12. Guess.
[0028]
While maintaining such a state, the support base 36 supports the end surface of the annular guide portion 24 on the vehicle outer side, for example, the bottom surface 24b of the concave portion 24a of the annular guide portion 24 as shown in FIG. Then, the caulking tool 35 is inserted from the vehicle outer side of the second inner ring member 9, and its tip is inserted into the central concave portion 26 b of the caulked portion 26 a which is the end of the cylindrical shaft portion 23 of the shaft 22. Then, caulking is performed so as to expand the caulked portion 26 a, and is pressed against the inclined stepped surface 21 of the inclined portion 20 to form the caulked portion 26.
[0029]
By doing so, the inner end surface of the annular guide portion 24 on the vehicle inner side presses against the end surface of the hub flange 12 by the caulking force at that time, and the one raceway portion 10 and the second inner ring member 9 of the first inner ring member 8 On the other hand, the end faces 10a and 15a of the track portion 15 are pressed against each other in the axial direction, and a predetermined preload is applied to the balls 4 and 5 in both rows.
[0030]
Since the inclined end 20a of the inclined portion 20 is located at a substantially intermediate portion between the vehicle outer side end surface of the first inner ring member 8 and the vehicle inner side end surface of the second inner ring member 9, the vehicle outer side end surface is provided. The axial distance from the (bottom surface 24b of the concave portion 24a of the annular guide portion 24) to the portion to be swaged 26a is short. Therefore, it is possible to prevent a buckling phenomenon in which the cylindrical shaft portion 23 of the shaft body 22 is greatly deformed during caulking.
[0031]
As described above, the end faces 10a and 15a of the one raceway portion 10 of the first inner race member 8 and the other raceway portion 15 of the second inner race member 9 can be securely pressed against each other in the axial direction. By applying a predetermined preload to the balls 4 and 5 reliably, the rolling bearing device 1 having sufficient rigidity and stability can be obtained.
[0032]
After assembling the rolling bearing device 1 as described above, the brake disc 11 and the tire wheel 13 are guided to the hub flange 12 through the guide holes 25 formed in the central portions thereof at the guide surfaces 25 of the annular guide portion 24. Mount on top of each other.
[0033]
In the rolling bearing device 1 having the above-described configuration, when the vehicle travels, the first inner ring member 8 and the second inner ring member 9 rotate around the axis together with the shaft body 22 with the rotation of the wheels (not shown).
[0034]
By the way, the shaft body 22 and the second inner ring member 9 in the rolling bearing device 1 are formed by cold forging using a tubular material. For this reason, the whole capacity and weight of the rolling bearing device 1 can be reduced as compared with the case where the hub shaft is formed into a solid cross section by hot forging as in the conventional example. As a result, it is possible to reduce the vehicle weight (particularly, the unsprung weight).
[0035]
Further, as compared with the case where the hub axle is formed into a solid cross section by hot forging as in the conventional example, even small-scale and inexpensive manufacturing equipment can be used, and the second inner ring member 9 can be formed with high precision. Can be molded. That is, in the case of hot forging, the surface accuracy of the product is low, and in particular, a long grinding time is required to make the inner ring raceway surface of the ball 5 necessary accuracy, and in some cases, a portion other than the inner ring raceway surface is also ground. Needed. On the other hand, in the case where the second inner race member 9 is formed by cold forging using a tubular material, the material cost is inexpensive, and it can be manufactured with high accuracy. Polishing time for accuracy can be shortened, and polishing of portions other than the inner ring raceway surface is almost unnecessary. This can significantly reduce manufacturing costs.
[0036]
FIG. 5 shows another manufacturing method, in which one row of balls 4 is brought into contact with the inner raceway surface of one raceway portion 10, and the other ball 5 is brought into contact with the inner raceway surface of the other raceway portion 15. At this point, as shown in the drawing, the end faces 10a and 15a are brought into pressure contact with each other, and the axial dimension between the raceway surfaces is set so that a predetermined preload is applied to the balls 4 and 5 in both rows. The case where the axial dimension of the part 15 is set is shown.
[0037]
Then, the end faces 10a and 15a are pressed against each other, and a state where a predetermined preload is applied to the balls 4 and 5 in both rows is maintained, and the caulking tool 35 is inserted from the vehicle outer side of the second inner ring member 9. Then, the leading end is inserted into the central concave portion 26b of the portion to be caulked 26a, which is the end of the cylindrical shaft portion 23 of the shaft body 22, and caulking is performed so as to expand the diameter thereof. The caulked portion 26 is formed by pressing against the attachment surface 21.
[0038]
In this way, the end faces 10a and 15a are pressed against each other in advance, and the state where a predetermined preload is applied to the balls 4 and 5 in both rows is maintained, and the caulked portion 26a is caulked on the inclined stepped surface 21 of the inclined portion 20. By deforming and caulking and forming the caulked portion 26, it is possible to prevent unnecessary force from acting on the balls 4 and 5 at the time of caulking, so that the balls 4 and 5 are damaged at the time of manufacturing the rolling bearing device 1 ( Indentation) can be prevented. Alternatively, damage to the raceway surface can be prevented.
[0039]
【The invention's effect】
As is apparent from the above description, according to the present invention, the first inner ring member and the second inner ring member can be surely integrated without causing buckling of the shaft body, and the rolling element Preload can be applied. Furthermore, not only expensive and large-scale equipment is not required, but also post-processing time such as polishing or turning can be shortened or omitted, so that manufacturing cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an overall configuration of a rolling bearing device according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view of the same.
FIG. 3 is a cross-sectional view of the same in the middle of manufacture.
FIG. 4 is an overall sectional view of the rolling bearing device in the course of manufacture.
FIG. 5 is an enlarged fragmentary cross-sectional view showing another method of manufacturing the rolling bearing device according to the embodiment of the present invention.
FIG. 6 is a cross-sectional view showing the entire configuration of a conventional rolling bearing device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rolling bearing device 2 Outer ring member 8 First inner ring member 9 Second inner ring member 10 One track portion 12 Hub flange 15 Other track portion 16 Fitting portion 20 Inclined portion 21 Inclined stepped surface 22 Shaft 24 Annular guide 26 Caulking part

Claims

An outer ring member, an inner ring member arranged concentrically with the outer ring member, and a double row rolling element interposed rotatably between the two members, wherein the inner ring member is arranged on one axial side. A first inner race member having an inner raceway surface of one row of rolling elements and having a flange for mounting a brake disc, and a second inner race member which is in contact with the first inner race member on the other side in the axial direction and is adjacent to the first inner race member. With an inner ring member,
The second inner race member has a raceway portion having an outer raceway surface in the other row on the outer peripheral surface thereof, and is fitted so as to be reduced in diameter from the raceway portion and extended along the inner peripheral surface of the first inner race member. A mating portion is included, and an inner peripheral surface of a continuous portion of the track portion and the fitting portion is formed with a stepped surface as the diameter is reduced from the track portion to the fitting portion,
A shaft is inserted into the fitting portion from one side in the axial direction, and the other end of the shaft in the axial direction is caulked to the stepped surface, and one end of the shaft in the axial direction is provided. A rolling bearing device, wherein a radially enlarged portion is formed radially outwardly, and an end surface of the enlarged diameter portion is pressed against an end surface of the flange.

The rolling bearing device according to claim 1,
A rolling bearing device, wherein a guide surface for mounting the brake disc by overlapping it with a flange is formed on an outer peripheral surface of the enlarged diameter portion.