JP4381664B2

JP4381664B2 - Current-carrying bearing

Info

Publication number: JP4381664B2
Application number: JP2002244057A
Authority: JP
Inventors: 浩義伊藤; 秀雄福森
Original assignee: NTN Corp; Tsurumi Manufacturing Co Ltd
Current assignee: NTN Corp; Tsurumi Manufacturing Co Ltd
Priority date: 2002-08-23
Filing date: 2002-08-23
Publication date: 2009-12-09
Anticipated expiration: 2022-08-23
Also published as: JP2004084730A

Description

【０００１】
【発明の属する技術分野】
この発明は、軸とハウジング間に電位差のある箇所に用いられて両者間に微小電流を流す構造とされ、軌道輪と転動体との間に生じる電食を防止できる通電軸受に関する。
【０００２】
【従来の技術と発明が解決しようとする課題】
従来、通電軸受として、シールやグリースに導電性を持つ物質を混合させたものが、一般的に知られている。
しかし、シールに導電性を持つ物質を混合させた場合、回転初期は安定して電流を流すことが可能でも、短時間でシールの摩耗が大きくなり、軸受内輪と外輪間の電気抵抗が次第に大きくなって、電流が流れ難くなるという欠点がある。
また、グリースに導電性を持つ物質を混合させた例では、転動体と軌道輪の転走面間の接触面圧が大きくなった場合、グリースの油膜切れが生じて、導電性物質が転動体と転走面の間から排除され、電気抵抗が大きくなることがある。また、グリースに混合した導電性物質が時間の経過と共にグリースと分離することにり、転動体と転走面の間に導電性物質が侵入できなくなり、電気抵抗が大きくなることがある。
【０００３】
また、通電軸受の他の従来例として、図１３に示すように、軸受の内輪５１と外輪５２の間に細線状の導電性材料５３を介在させた構成のものが提案されている（実開昭６２−１７０８２９号公報）。
しかし、このような構成では、軸受の回転に伴い、内外輪５１，５２とばね５３との接触部に封入グリースが介在し、内外輪５１，５２の間の電気抵抗が大きくなるという問題点がある。
【０００４】
この発明の目的は、軸受の内外輪間の電気抵抗を安定して小さくできて、転走面に電食が生じ難くなる通電軸受を提供することである。
【０００５】
【課題を解決するための手段】
この発明における第１の発明の通電軸受は、それぞれ内輪および外輪となる一対の軌道輪の間に転動体を介在させた転がり軸受であって、導電性を有し外輪の内径面に嵌合する円筒部、および外輪の幅面と当接するフランジ部を有する取付部材を介して、弾性および導電性を有する導電性部材を上記外輪に取付け、この導電性部材の先端を、内輪に取付けられた導電性の接触部材に対して、軸方向を向く面に接触させ、これら導電性部材の先端と接触部材との接触部を軸受の軸方向外方に設け、上記弾性および導電性を有する導電性部材が、板ばねまたはコイルばねであり、上記内輪に取付けられた導電性の接触部材が、リング状であって、内輪の外径面に嵌合する円筒部と、この円筒部の一端から内径側および外径側の両方に延びる環状帯部とを有し、上記円筒部を内輪の外径面に圧入嵌合させ、環状帯部の内径側部分を内輪の幅面に当接させることで、上記接触部材が内輪に取付けられ、この接触部材における上記環状帯部の外径側部分と、上記取付部材の上記外向きフランジ部とで、軸受内部の潤滑剤が取付部材と接触部材との接触部に漏れ出ることを防ぐ仕切壁を形成したものである。
この構成によると、内輪と外輪の間に電位差が発生しても、内輪と外輪との間には、導電性の取付部材、導電性部材、および導電性の接触部材により電気抵抗の小さいバイパス回路が形成されるため、このバイパス回路を電流が流れることになる。そのため、内外輪の転走面と転動体との間に電流が流れることが防止され、転走面に電食が発生し難くなる。また、内輪と外輪間の電気抵抗を小さくすることができるので、軸と軸受ハウジングの間に微小電流を流すことができる。
また、外輪に取付けた導電性部材と、内輪に取付けられた接触部材とを接触させるので、両軌道輪に対して接触する一つの導電性部材を設ける場合に比べて、転走面から離れた位置で接触させることが容易で、絶縁性の封入グリースの介在による電気抵抗増加が避け易い。また、ハウジングに導電性部材を取付けるものと異なり、軸受自体に導電性部材を備えるため、機器への組み立てが容易である。
【０００６】
この発明において、上記導電性部材は弾性体とする。導電性部材を弾性体とすると、そのばね力で接触部材に押し当てられるので、導電性部材または接触部材が摩耗しても、接触抵抗が経時的に大きくならず、より安定して電流を流すことができる。
導電性部材とする弾性体は、例えば板ばねやコイルばね等のばね状のものであっても良い。導電性部材を板ばね形状とする場合、その先端部を櫛歯状としても良い。導電性部材を板ばね形状とし、またその先端を櫛歯状とした場合、内外輪の軸心が相対的に傾いても、接触部材に対して導電性部材が片当たりとなることが防止され、接触部材への接触が安定する。
【０００７】
また、この発明において、上記接触部材の軸方向を向く面に上記導電性部材を接触させたものとしても良い。軸方向に向く面で接触させるようにした場合、接触面のグリースの介在が避け易い。この場合に、内輪回転であっても、外輪回転であっても良い。
また、上記取付部材は、外輪の内径面に嵌合する円筒部、および外輪の幅面と当接するフランジ部を有するものとする。この円筒部の嵌合により、取付部材を容易に外輪に取付けることができ、かつフランジ部で軸方向の位置が規制できて、接触がより安定する。
さらに、上記内輪に取付けられた導電性の接触部材が、リング状であって、内輪の外径面に嵌合する円筒部と、この円筒部の一端から内径側および外径側の両方に延びる環状帯部とを有し、上記円筒部を内輪の外径面に圧入嵌合させ、環状帯部の内径側部分を内輪の幅面に当接させることで、上記接触部材が内輪に取付けられていても良い。また、この接触部材における上記環状帯部の外径側部分と、上記取付部材の上記外向きフランジ部とで、軸受内部の潤滑剤が取付部材と接触部材との接触部に漏れ出ることを防ぐ仕切壁を形成しても良い。
【００１１】
また、これらの発明において、上記一対の軌道輪の間に熱固化型グリースを封入しても良い。熱固化型グリースを用いると、軸受内部からのグリース漏れが無くなり、導電性部材と接触部材との接触部にグリースが介在することがなく、グリース介在に起因する電気抵抗の増大を回避できる。
【００１２】
【発明の実施の形態】
この発明の第１の実施形態を図１および図２と共に説明する。図１（Ａ）はこの通電軸受の断面図を示す。この通電軸受は、軌道輪である内輪１と外輪２の間に転動体３を介在させた転がり軸受であって、ここでは回転軸１１に嵌着される内輪１が回転側軌道輪とされ、外輪２が固定側軌道輪とされている。転動体３は保持器４で保持されている。転動体３は、鋼球等のボールが用いられ、この通電軸受は、深溝玉軸受とされている。内外輪１，２は軸受鋼等の金属製である。
【００１３】
外輪２の一端部に、導電性材料からなる取付部材５を介して複数の板ばね形状の導電性部材６が取付けられている。導電性部材６は、１個でも、また３個以上であっても良い。取付部材５は鋼板等の金属板とされ、またプレス加工が容易な材質のものとされている。導電性部材６は、ばね性を有する鋼板やその他の金属板が用いられている。
図１（Ｂ）は取付部材５の断面図を示す。取付部材５はリング状であって、外輪２の内径面に嵌合する円筒部５ａと、外輪２の幅面に当接する外向きフランジ部５ｂと、内向きフランジ部５ｃとを有する。取付部材５は１枚の金属板のプレス加工品からなり、外向きフランジ部５ｂは、円筒部５ａの一端から外径側へ延びて、外径縁で折り返された２重形状とされ、片方の折り返し板部分は円筒部５ａよりも内径側へ延び、その内径端から上記円筒部５ａと反対側へ延びる円筒部５ｄを介して上記内向きフランジ部５ｃが内径側へ延びている。上記ばね状の導電性部材６は、内向きフランジ部５ｃに取付けられている。上記嵌合用の円筒部５ａを外輪２の内径面に圧入嵌合させ、外向きフランジ部５ｂを外輪２の幅面に当接させることで、取付部材５が外輪２に取付けられる。
【００１４】
図１（Ａ）におけるＩ−Ｉ矢視断面図を示す図２（Ａ）のように、上記取付部材５における内向きフランジ部５ｃの軸受対向側の面に、一対の導電性部材６，６が１８０°の周回角度を隔てて配置され、リベット等の固着具７によって内向きフランジ部５ｃに取付けられている。これら導電性部材６は板ばねであって、図２（Ａ）におけるII−II矢視断面図を示す図２（Ｂ）のように、固着具７による内向きフランジ部５ｃへの取付端部から他端部側６ａが軸受側に若干起き上がるように折れ曲がっている。導電性部材６の先端は、内向きフランジ部５ｃ側へ若干折り曲げられて接触端部６ｂとされている。また、これら導電性部材６は、その接触端部６ｂとなる先端部が軸１１の回転方向Ｒの前方に向くように配置されている。
導電性部材６の先端部である接触端部６ｂは、単純な平板状としたが、例えば図２（Ｃ）に示すように、長さ方向に沿う複数のスリット６ｂｂが平行に形成されて、複数の櫛歯６ｂａが平行に延びる櫛歯状としても良い。
【００１５】
図１に示すように、内輪１の上記取付部材５と対向する端部には導電性材料からなる接触部材８が取付けられ、この接触部材８に導電性部材６の接触端部６ｂが接触させてある。図１（Ｃ）は上記接触部材８の断面図を示す。この接触部材８はリング状であって、内輪１の外径面に嵌合する円筒部８ａと、この円筒部８ａの一端から内径側および外径側の両方に延びる環状帯部８ｂとを有する。上記円筒部８ａを内輪１の外径面に圧入嵌合させ、環状帯部８ｂの内径側部分を内輪１の幅面に当接させることで、接触部材８が内輪１に取付けられる。この接触部材８における環状帯部８ｂの外径側部分と、取付部材５の外向きフランジ部５ｂとで、軸受内部の潤滑剤が取付部材５と接触部材８との接触部に漏れ出ることを防ぐ仕切壁が形成されている。内外輪１，２間の空間の取付部材５とは反対側の端部は、外輪２に取付けられたシール部材９で封止されている。内外輪１，２間に封入する潤滑剤は、一般のグリースであっても良いが、熱固化型グリースが封入されている。熱固化型グリースは、初期状態では流動性を有していて、熱を与えることによって固形化するものであり、封入後に加熱により固形化される。
【００１６】
この構成によると、内輪１と外輪２の間に電位差が発生しても、内輪１と外輪２との間には、取付部材５と導電性部材６と接触部材８とで電気抵抗の小さいバイパス回路が形成されるため、このバイパス回路を電流が流れることになり、内外輪１，２の転走面と転動体３との間に電流が流れることが防止される。そのため、内外輪１，２の転走面に電食が発生し難くなる。
また、取付部材５に取付けられた導電性部材６は板ばねとされ、そのばね力で接触部材８に押し当てられているので、導電性部材６の接触端部６ｂが摩耗してもばね力は継続して働き、常に導電性部材６が接触部材８に接触した状態を保つことができる。したがって、内外輪１，２間に形成される上記バイパス回路の電気抵抗を長期にわたって安定して小さくできる。導電性部材６を図２（Ｃ）に示すように櫛歯状とした場合は、内外輪１，２の軸心が相対的な傾きによる接触の不安定さを克服することができる。
【００１７】
取付部材５は、その円筒部５ａを外輪２の内径面に圧入嵌合させ、外向きフランジ部５ｂを外輪２の幅面に当接させることで外輪２に取付けられるので、取付部材５の軸方向および径方向の移動を確実に規制でき、導電性部材６の接触部材８への接触をより安定させることができる。
内外輪１，２間の潤滑剤として上記のように熱固化型グリースを封入した場合は、軸受内部からのグリース漏れが無くなる。そのため、導電性部材６と接触部材８との接触部にグリースが介在することがなく、グリース介在に起因する電気抵抗の増大を回避できる。
【００１８】
図３および図４は、この発明の参考提案例を示す。この通電軸受は、図１および図２に示した第１の実施形態において、内輪１に取付けられるリング状の接触部材８に代えて、取付部材５に対向する回転軸１１の端面の軸中心に、ボルトからなる接触部材８Ａが取付けてある。接触部材８Ａは、回転軸１１の端面に形成されたねじ孔に螺合して取付けられる。また、板ばねからなる導電性部材６は、接触端部６ｂが接触部材８Ａのボルト頭部８Ａａの中央に押し当てられている。導電性部材６は、取付部材５の内向きフランジ部５ｃから中央に向けて延ばした取付片５ｄに、リベット等の固着具７により取付けられている。内外輪１，２間の取付部材５に対向する端部環状空間は、取付部材５の円筒部５ａから内径側に延びる仕切り部５ｅにより封止されている。その他の構成は第１の実施形態と同じである。
【００１９】
この参考提案例では、導電性部材６を回転軸１１の軸中心で接触部材８Ａに接触させているので、接触部材８Ａの導電性部材６との接触部の周速が非常に小さく、略零になり、接触部の摩耗を小さく抑えることができる。これにより、導電性部材６や接触部材８Ａの寿命が向上し、また摩耗が小さいため、回転軸１１の許容回転数を大きくすることが可能となる。
【００２０】
図５，図６は、この発明のさらに他の参考提案例を示す。この通電軸受は、図３および図４に示した実施形態において、回転軸１１の端面の軸中心に設ける接触部材として、コンタクトプローブ８Ｂが用いられている。このコンタククトプローブ８Ｂは、回転軸１１内に回転軸１１と同心状に装着したガイドスリーブ１２と、導電性材料からなり上記ガイドスリーブ１２内に挿入されて軸方向に進退自在な進退ロッド１３と、上記ガイドスリーブ１２が装着される回転軸１１のスリーブ装着穴１１ａの底部と前記進退ロッド１３の後端との間に介装され、進退ロッド１３を取付部材５側に付勢する導電性ばね部材１４とで構成される。進退ロッド１３の先端部１３ａは凸球面状とされ、この先端部１３ａに導電性部材６の接触端部６ｂが押し当てられる。これにより、外輪２と内輪１との間には、取付部材５、導電性部材６、進退ロッド１３、導電性ばね部材１４、および回転軸１１からなる電気抵抗の小さいバイパス回路が構成される。また、取付部材５への導電性部材６の取付けは、これまでの実施形態または参考提案例のようにリベッドからなる固着具７で行うのに代えて、ここではねじ部材であるボルト１５とナット１６により締付け固定するようにしている。なお、内外輪１，２の間の空間の取付部材５に対向する側の端部は、取付部材５の円筒部５ａの内径面に嵌合させたシール部材１０で封止されている。その他の構成は図３および図４の参考提案例と同じである。
【００２１】
この参考提案例の場合は、導電性部材６を、接触部材として回転軸１１の軸中心に設けられたコンタクトプローブ８Ｂの進退ロッド先端部１３ａに押し当てているので、接触部材８Ｂの導電性部材６との接触部の周速が非常に小さくなり、接触部の摩耗をより小さく抑えることができる。また、回転軸１１が軸方向に振動したとき、その振動をコンタクトプローブ８Ｂの導電性ばね部材１４で吸収でき、導電性部材６の接触部材８Ｂへの接触圧を一定に保つことができる。また、導電性部材６をボルト１５とナット１６とで取付部材５に締付け固定しているので、導電性部材６が摩耗したときに、これを容易に交換することができる。
【００２２】
図７，図８は、この発明のさらに他の参考提案例を示す。この通電軸受は、図３および図４に示した参考提案例において、回転軸１１の端面の軸中心に設ける接触部材として、ボールプランジャ８Ｃが用いられている。このボールプランジャ８Ｃは、回転軸１１内に回転軸１１と同心状に装着した有底の導電性ガイド筒１７と、この導電性ガイド筒１７内に配置される導電性ボール１８と、前記導電性ガイド筒１７内におけるその底部１７ａと前記導電性ボール１８との間に介装され、導電性ボール１８を取付部材５側に付勢する導電性ばね部材１９とで構成される。導電性ガイド筒１７の先端側口縁にはその先端から導電性ボール１８が所定以上進出するのを規制するストッパ部材２０が設けられ、その導電性ボール１８に導電性部材６の接触端部６ｂが押し当てられる。これにより、外輪２と内輪１との間には、取付部材５、導電性部材６、導電性ボール１８、導電性ばね部材１９、導電性ガイド筒１７、および回転軸１１からなる電気抵抗の小さいバイパス回路が構成される。内外輪１，２の間の空間の取付部材５に対向する側の端部が、取付部材５の円筒部５ａの内径面に嵌合させたシール部材１０で封止されることは、図５，図６に示した参考提案例と同じである。その他の構成は図３，図４の参考提案例と同じである。
【００２３】
この参考提案例の場合も、導電性部材６を、接触部材として回転軸１１の軸中心に設けられたボールプランジャ８Ｃの導電性ボール１８に接触させたので、接触部の周速が非常に小さくなり、接触部の摩耗を小さく抑えることができる。また、回転軸１１が軸方向に振動したときに、その振動をボールプランジャ８Ｃの導電性ばね部材１９で吸収できるので、導電性部材６の接触部材８Ｃへの接触圧を一定に保つことができる。
【００２４】
図９，図１０は、この発明のさらに他の参考提案例を示す。この通電軸受は、図３および図４に示した参考提案例において、取付部材５への導電性部材６の取付けを、リベットからなる固着具７に代えて、ボルト１５とナット１６により締付け固定している。これにより、導電性部材６が摩耗したときに、これを容易に交換することもできる。なお、内外輪１，２の間の空間の取付部材５と対向する側の端部は、取付部材５の円筒部５ａの内径面に嵌合させたシール部材１０で封止されている。
【００２５】
図１１，図１２は、この発明のさらに他の参考提案例を示す。この通電軸受は、図５，図６に示した参考提案例において、取付部材５への導電性部材６の取付けを、ボルト１５とナット１６による締付け固定に代えて、取付部材５の取付片５ｄに形成したバーリング加工部５ｆの内周面の雌ねじ部５ｆａにボルト２１を螺合させることで、導電性部材６を締付け固定するようにしている。その他の構成は図５，図６の参考提案例と同じである。
【００２６】
この参考提案例の場合は、取付部材５のバーリング加工部５ｆに螺合させたボルト２１で、導電性部材６を取付部材５に締付け固定しているので、導電性部材６を交換可能に取付ける構造を少ない部品点数で実現でき、コストの低減および組立の簡略化が可能となる。
【００２７】
なお、上記実施形態および各参考提案例の構成の通電軸受は、内外輪１，２間に予期しない電圧差が生じたときに、転動体３を避けたバイパス回路を経て電流を流す場合に限らず、所定の電気回路の通電路の一部として上記バイパス回路を利用する場合にも適用可能である。
【００２８】
なお、上記実施形態および各参考提案例は内輪１が回転するものとしたが、外輪２が回転するものとし、内輪２は固定の軸（図示せず）に取付けられるものとしても良い。
【００２９】
【発明の効果】
この発明の通電軸受は、導電性を有し外輪の内径面に嵌合する円筒部、および外輪の幅面と当接するフランジ部を有する取付部材を介して、弾性および導電性を有する導電性部材を上記外輪に取付け、この導電性部材の先端を、内輪に取付けられた導電性の接触部材に対して、軸方向を向く面に接触させ、これら導電性部材の先端と接触部材との接触部を軸受の軸方向外方に設け、上記弾性および導電性を有する導電性部材が、板ばねまたはコイルばねであり、上記内輪に取付けられた導電性の接触部材が、リング状であって、内輪の外径面に嵌合する円筒部と、この円筒部の一端から内径側および外径側の両方に延びる環状帯部とを有し、上記円筒部を内輪の外径面に圧入嵌合させ、環状帯部の内径側部分を内輪の幅面に当接させることで、上記接触部材が内輪に取付けられ、この接触部材における上記環状帯部の外径側部分と、上記取付部材の上記外向きフランジ部とで、軸受内部の潤滑剤が取付部材と接触部材との接触部に漏れ出ることを防ぐ仕切壁を形成したため、軸受の内外輪間の電気抵抗を安定して小さくできて、転走面に電食が生じ難くいものとなり、また軸とハウジング間に微小電流を流すことが可能になる。また、一方の軌道輪に取付けた導電性部材と、他方の軌道輪に取付けられた接触部材とを接触させるので、両軌道輪に対して接触する一つの導電性部材を設ける場合に比べて、転走面から離れた位置で接触させることが容易で、絶縁性の封入グリースの介在による電気抵抗増加が避け易い。また、ハウジングに導電性部材を取付けるものと異なり、軸受自体に導電性部材を備えるため、機器への組み立てが容易である。導電性部材を弾性体とした場合は、摩耗が生じても接触抵抗が経時的に大きくならず、より安定して電流を流すことができる。
この発明において、潤滑剤として熱固化型グリースを封入した場合は、グリースの介在に起因する電気抵抗の増大を回避できる。
【図面の簡単な説明】
【図１】（Ａ）はこの発明の一実施形態にかかる通電軸受の断面図、（Ｂ），（Ｃ）は同通電軸受における取付部材および接触部材の断面図である。
【図２】（Ａ）は図１におけるＩ−Ｉ矢視断面図、（Ｂ）は（Ａ）におけるII−II矢視断面図、（Ｃ）は接触部材の変形例の平面図である。
【図３】この発明の参考提案例にかかる通電軸受の断面図である。
【図４】同通電軸受の正面図である。
【図５】この発明の他の参考提案例にかかる通電軸受の断面図である。
【図６】同通電軸受の正面図である。
【図７】この発明のさらに他の参考提案例にかかる通電軸受の断面図である。
【図８】同通電軸受の正面図である。
【図９】この発明のさらに他の参考提案例にかかる通電軸受の断面図である。
【図１０】同通電軸受の正面図である。
【図１１】この発明のさらに他の参考提案例にかかる通電軸受の断面図である。
【図１２】同通電軸受の正面図である。
【図１３】従来例の正面図である。
【符号の説明】
１…内輪（軌道輪）
２…外輪（軌道輪）
５…取付部材
５ａ…円筒部
５ｂ…外向きフランジ部
５ｆ…バーリング加工部
５ｆａ…雌ねじ部
６…導電性部材
８，８Ａ，８Ｂ，８Ｃ…接触部材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a current-carrying bearing that is used in a portion where there is a potential difference between a shaft and a housing and has a structure in which a minute current flows between the shaft and the housing, and can prevent electrolytic corrosion generated between a race and a rolling element.
[0002]
[Prior art and problems to be solved by the invention]
Conventionally, a current-carrying bearing in which a conductive material is mixed with a seal or grease is generally known.
However, when a conductive material is mixed in the seal, even if a stable current can flow at the beginning of rotation, wear of the seal increases in a short time, and the electrical resistance between the bearing inner ring and outer ring gradually increases. Thus, there is a drawback that it becomes difficult for current to flow.
In addition, in the example in which a conductive material is mixed in the grease, if the contact surface pressure between the rolling element and the raceway surface of the raceway increases, the grease oil film breaks, and the conductive material becomes rolling element. And is excluded from between the rolling surfaces, and the electrical resistance may increase. In addition, the conductive substance mixed in the grease is separated from the grease with the passage of time, so that the conductive substance cannot enter between the rolling elements and the rolling surface, and the electrical resistance may increase.
[0003]
As another conventional example of a current-carrying bearing, a configuration in which a thin wire-shaped conductive material 53 is interposed between an inner ring 51 and an outer ring 52 of the bearing as shown in FIG. Sho 62-170829).
However, in such a configuration, with the rotation of the bearing, the sealed grease is interposed in the contact portion between the inner and outer rings 51 and 52 and the spring 53, and the electrical resistance between the inner and outer rings 51 and 52 is increased. is there.
[0004]
An object of the present invention is to provide an energized bearing in which the electrical resistance between the inner and outer rings of the bearing can be reduced stably, and electrolytic corrosion is less likely to occur on the rolling surface.
[0005]
[Means for Solving the Problems]
A current-carrying bearing according to a first aspect of the present invention is a rolling bearing in which a rolling element is interposed between a pair of race rings that are an inner ring and an outer ring, respectively, and has electrical conductivity and is fitted to the inner diameter surface of the outer ring. cylindrical portion, and via a mounting member having a width surface contacting the flange portion of the outer ring, fitted with a conductive member having elasticity and conductivity to the outer ring, the front end of this conductive member, the conductive attached to the inner ring for the sexual contact member is brought into contact with a surface facing the axial direction, the contact portion between the tip and the contact member of electrically conductive members disposed axially outwardly of the bearing, the conductive member having the elasticity and conductivity Is a leaf spring or a coil spring, and the conductive contact member attached to the inner ring has a ring shape, and a cylindrical portion that fits to the outer diameter surface of the inner ring, and an inner diameter side from one end of the cylindrical portion. Annular band extending to both the outer diameter side The cylindrical member is press-fitted and fitted to the outer diameter surface of the inner ring, and the inner diameter side portion of the annular belt portion is brought into contact with the width surface of the inner ring, whereby the contact member is attached to the inner ring. A partition wall that prevents the lubricant inside the bearing from leaking into the contact portion between the mounting member and the contact member is formed by the outer diameter side portion of the annular belt portion and the outward flange portion of the mounting member. Is.
According to this configuration, even if a potential difference occurs between the inner ring and the outer ring, a bypass circuit having a small electric resistance is provided between the inner ring and the outer ring by the conductive mounting member, the conductive member, and the conductive contact member. Therefore, a current flows through this bypass circuit. Therefore, current is prevented from flowing between the rolling surfaces of the inner and outer rings and the rolling elements, and it is difficult for electrolytic corrosion to occur on the rolling surfaces. In addition, since the electrical resistance between the inner ring and the outer ring can be reduced, a minute current can flow between the shaft and the bearing housing.
In addition, since the conductive member attached to the outer ring and the contact member attached to the inner ring are brought into contact with each other, it is separated from the rolling surface as compared with the case where one conductive member that makes contact with both race rings is provided. It is easy to make contact at a position, and it is easy to avoid an increase in electrical resistance due to the inclusion of insulating sealed grease. Further, unlike the case where the conductive member is attached to the housing, the bearing itself is provided with the conductive member, so that assembly to the device is easy.
[0006]
In the present invention, the conductive member is an elastic body. If the conductive member is an elastic body, it is pressed against the contact member by its spring force, so even if the conductive member or the contact member wears, the contact resistance does not increase with time, and the current flows more stably. be able to.
Elastic body and the conductive member may be for example one spring-like, such as a leaf spring or a coil spring. When the conductive member has a leaf spring shape, the tip end portion may have a comb shape. When the conductive member has a leaf spring shape and the tip thereof has a comb-teeth shape, it is prevented that the conductive member comes into contact with the contact member even if the axial center of the inner and outer rings is relatively inclined. The contact to the contact member is stabilized.
[0007]
Further, the present invention smell Te may be those obtained by contacting the conductive member to the surface facing the axial direction of the upper Symbol contact member. When contact is made on the surface facing in the axial direction, it is easy to avoid the presence of grease on the contact surface. In this case, it may be inner ring rotation or outer ring rotation.
Further, the mounting member is a cylindrical portion that fits into the inner diameter surface of the outer ring, and assumed to have a width surface contacting the flange portion of the outer ring. The engagement of the cylindrical portion, the mounting member can be easily attached to the outer ring, and the axial position at the flange portion made regulations, contact you more stable.
Furthermore, the conductive contact member attached to the inner ring is ring-shaped, and extends to both the inner diameter side and the outer diameter side from one end of the cylindrical part that is fitted to the outer diameter surface of the inner ring. The contact member is attached to the inner ring by press-fitting the cylindrical part to the outer diameter surface of the inner ring and bringing the inner diameter side portion of the annular band part into contact with the width surface of the inner ring. May be. Also, the lubricant inside the bearing is prevented from leaking to the contact portion between the mounting member and the contact member by the outer diameter side portion of the annular band portion in the contact member and the outward flange portion of the mounting member. A partition wall may be formed.
[0011]
In these inventions, heat-setting grease may be enclosed between the pair of race rings. When the heat-solidifying grease is used, grease leakage from the inside of the bearing is eliminated, and no grease is present at the contact portion between the conductive member and the contact member, so that an increase in electrical resistance due to the presence of the grease can be avoided.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1A shows a cross-sectional view of this energizing bearing. This energizing bearing is a rolling bearing in which a rolling element 3 is interposed between an inner ring 1 and an outer ring 2 which are raceways. Here, the inner race 1 fitted to the rotary shaft 11 is a rotary raceway, The outer ring 2 is a fixed side ring. The rolling element 3 is held by a cage 4. The rolling element 3 is a ball such as a steel ball, and this energized bearing is a deep groove ball bearing. The inner and outer rings 1 and 2 are made of metal such as bearing steel.
[0013]
A plurality of leaf spring-shaped conductive members 6 are attached to one end of the outer ring 2 via attachment members 5 made of a conductive material. There may be one conductive member 6 or three or more conductive members 6. The attachment member 5 is a metal plate such as a steel plate, and is made of a material that can be easily pressed. The conductive member 6 is a spring steel plate or other metal plate.
FIG. 1B shows a cross-sectional view of the mounting member 5. The attachment member 5 has a ring shape, and includes a cylindrical portion 5 a that fits to the inner diameter surface of the outer ring 2, an outward flange portion 5 b that contacts the width surface of the outer ring 2, and an inward flange portion 5 c. The mounting member 5 is made of a pressed product of a single metal plate, and the outward flange portion 5b extends from one end of the cylindrical portion 5a to the outer diameter side and has a double shape folded at the outer diameter edge. The folded plate portion extends to the inner diameter side from the cylindrical portion 5a, and the inward flange portion 5c extends to the inner diameter side via a cylindrical portion 5d extending from the inner diameter end to the opposite side of the cylindrical portion 5a. The spring-like conductive member 6 is attached to the inward flange portion 5c. The fitting member 5 is attached to the outer ring 2 by press-fitting the fitting cylindrical portion 5 a to the inner diameter surface of the outer ring 2 and bringing the outward flange portion 5 b into contact with the width surface of the outer ring 2.
[0014]
As shown in FIG. 2A, which shows a cross-sectional view taken along the line II in FIG. 1A, a pair of conductive members 6, 6 are provided on the bearing-facing side surface of the inward flange portion 5c of the mounting member 5. Are arranged at a circumferential angle of 180 ° and are attached to the inward flange portion 5c by a fixing tool 7 such as a rivet. These conductive members 6 are leaf springs, and as shown in FIG. 2 (B) showing a cross-sectional view taken along the line II-II in FIG. 2 (A), the attachment end portion to the inward flange portion 5c by the fixing tool 7 The other end 6a is bent so as to rise slightly to the bearing side. The front end of the conductive member 6 is bent slightly toward the inward flange portion 5c to form a contact end portion 6b. Further, the conductive members 6 are arranged such that the front end portion serving as the contact end portion 6 b faces forward in the rotation direction R of the shaft 11.
The contact end 6b, which is the tip of the conductive member 6, has a simple flat plate shape. For example, as shown in FIG. 2C, a plurality of slits 6bb along the length direction are formed in parallel. A plurality of comb teeth 6ba may have a comb shape extending in parallel.
[0015]
As shown in FIG. 1, a contact member 8 made of a conductive material is attached to the end of the inner ring 1 facing the mounting member 5, and the contact end 6 b of the conductive member 6 is brought into contact with the contact member 8. It is. FIG. 1C shows a cross-sectional view of the contact member 8. This contact member 8 is ring-shaped, and has a cylindrical portion 8a fitted to the outer diameter surface of the inner ring 1, and an annular band portion 8b extending from one end of the cylindrical portion 8a to both the inner diameter side and the outer diameter side. . The contact member 8 is attached to the inner ring 1 by press-fitting the cylindrical portion 8 a to the outer diameter surface of the inner ring 1 and bringing the inner diameter side portion of the annular band portion 8 b into contact with the width surface of the inner ring 1. The lubricant inside the bearing leaks into the contact portion between the mounting member 5 and the contact member 8 at the outer diameter side portion of the annular band portion 8b of the contact member 8 and the outward flange portion 5b of the mounting member 5. A partition wall is formed to prevent it. The end of the space between the inner and outer rings 1 and 2 opposite to the attachment member 5 is sealed with a seal member 9 attached to the outer ring 2. The lubricant encapsulated between the inner and outer rings 1 and 2 may be general grease, but is thermally solidified grease. The heat-solidifying grease has fluidity in an initial state and is solidified by applying heat, and is solidified by heating after sealing.
[0016]
According to this configuration, even if a potential difference occurs between the inner ring 1 and the outer ring 2, a bypass with a small electric resistance is provided between the inner ring 1 and the outer ring 2 by the mounting member 5, the conductive member 6, and the contact member 8. Since a circuit is formed, current flows through the bypass circuit, and current is prevented from flowing between the rolling surfaces of the inner and outer rings 1 and 2 and the rolling elements 3. Therefore, it is difficult for electric corrosion to occur on the rolling surfaces of the inner and outer rings 1 and 2.
Further, since the conductive member 6 attached to the attachment member 5 is a leaf spring and is pressed against the contact member 8 by the spring force, even if the contact end portion 6b of the conductive member 6 is worn, the spring force is applied. Works continuously and can always keep the conductive member 6 in contact with the contact member 8. Therefore, the electrical resistance of the bypass circuit formed between the inner and outer rings 1 and 2 can be stably reduced over a long period of time. When the conductive member 6 has a comb-teeth shape as shown in FIG. 2C, the instability of contact due to the relative inclination of the axes of the inner and outer rings 1 and 2 can be overcome.
[0017]
The attachment member 5 is attached to the outer ring 2 by press-fitting its cylindrical portion 5a to the inner diameter surface of the outer ring 2 and bringing the outward flange portion 5b into contact with the width surface of the outer ring 2, so the axial direction of the attachment member 5 In addition, the movement in the radial direction can be reliably controlled, and the contact of the conductive member 6 with the contact member 8 can be further stabilized.
When heat-setting grease is sealed as a lubricant between the inner and outer rings 1 and 2 as described above, grease leakage from the inside of the bearing is eliminated. Therefore, no grease is present at the contact portion between the conductive member 6 and the contact member 8, and an increase in electrical resistance due to the presence of grease can be avoided.
[0018]
3 and 4 show a reference proposal example of the present invention. In the first embodiment shown in FIG. 1 and FIG. 2, this energizing bearing replaces the ring-shaped contact member 8 attached to the inner ring 1 and is centered on the end surface of the rotary shaft 11 facing the attachment member 5. A contact member 8A made of a bolt is attached. The contact member 8 </ b> A is attached by being screwed into a screw hole formed on the end surface of the rotating shaft 11. Further, the conductive member 6 made of a leaf spring has a contact end 6b pressed against the center of the bolt head 8Aa of the contact member 8A. The conductive member 6 is attached to an attachment piece 5d extending from the inward flange portion 5c of the attachment member 5 toward the center by a fixing tool 7 such as a rivet. An end annular space facing the attachment member 5 between the inner and outer rings 1 and 2 is sealed by a partition portion 5e extending from the cylindrical portion 5a of the attachment member 5 to the inner diameter side. Other configurations are the same as those of the first embodiment.
[0019]
In this reference proposal example , since the conductive member 6 is brought into contact with the contact member 8A at the center of the rotating shaft 11, the peripheral speed of the contact portion of the contact member 8A with the conductive member 6 is very small and substantially zero. Thus, the wear of the contact portion can be kept small. Thereby, the lifetime of the conductive member 6 and the contact member 8A is improved and the wear is small, so that the allowable number of rotations of the rotating shaft 11 can be increased.
[0020]
5 and 6 show still another reference proposal example of the present invention. In this embodiment, the contact probe 8B is used as a contact member provided at the axial center of the end surface of the rotary shaft 11 in the embodiment shown in FIGS. The contact probe 8B includes a guide sleeve 12 mounted concentrically with the rotary shaft 11 in the rotary shaft 11, and a forward / backward rod 13 made of a conductive material and inserted into the guide sleeve 12 so as to be movable back and forth in the axial direction. The conductive spring is interposed between the bottom of the sleeve mounting hole 11a of the rotary shaft 11 to which the guide sleeve 12 is mounted and the rear end of the advance / retreat rod 13, and biases the advance / retreat rod 13 toward the mounting member 5. And the member 14. The distal end portion 13a of the advance / retreat rod 13 has a convex spherical shape, and the contact end portion 6b of the conductive member 6 is pressed against the distal end portion 13a. Thereby, between the outer ring 2 and the inner ring 1, a bypass circuit having a small electrical resistance is formed which includes the attachment member 5, the conductive member 6, the advance / retreat rod 13, the conductive spring member 14, and the rotating shaft 11. The attachment of the conductive member 6 to the mounting member 5, hitherto instead of doing so fastener 7 consisting Ribeddo as real施形state or references proposed example, where a screw member bolt 15 And a nut 16 for fastening. The end of the space between the inner and outer rings 1 and 2 facing the mounting member 5 is sealed with a seal member 10 fitted to the inner diameter surface of the cylindrical portion 5 a of the mounting member 5. Other configurations are the same as those of the reference proposal example of FIGS.
[0021]
In the case of this reference proposal example , the conductive member 6 is pressed against the forward / backward rod tip 13a of the contact probe 8B provided at the center of the rotating shaft 11 as a contact member, so the conductive member of the contact member 8B The peripheral speed of the contact part with 6 becomes very small, and the wear of the contact part can be further suppressed. Further, when the rotating shaft 11 vibrates in the axial direction, the vibration can be absorbed by the conductive spring member 14 of the contact probe 8B, and the contact pressure of the conductive member 6 to the contact member 8B can be kept constant. Further, since the conductive member 6 is fastened and fixed to the mounting member 5 by the bolt 15 and the nut 16, it can be easily replaced when the conductive member 6 is worn.
[0022]
7 and 8 show still another reference proposal example of the present invention. This energizing bearing uses a ball plunger 8 </ b> C as a contact member provided at the center of the end face of the rotating shaft 11 in the reference proposal example shown in FIGS. 3 and 4. The ball plunger 8C includes a bottomed conductive guide cylinder 17 mounted concentrically with the rotary shaft 11 in the rotary shaft 11, a conductive ball 18 disposed in the conductive guide cylinder 17, and the conductive material. A conductive spring member 19 is interposed between the bottom portion 17a of the guide tube 17 and the conductive ball 18, and biases the conductive ball 18 toward the mounting member 5. A stopper member 20 is provided at the leading edge of the conductive guide cylinder 17 to restrict the conductive ball 18 from advancing more than a predetermined distance from the tip, and the conductive ball 18 has a contact end 6b of the conductive member 6. Is pressed. Thereby, between the outer ring 2 and the inner ring 1, the electric resistance composed of the mounting member 5, the conductive member 6, the conductive ball 18, the conductive spring member 19, the conductive guide cylinder 17, and the rotating shaft 11 is small. A bypass circuit is configured. The end of the space between the inner and outer rings 1 and 2 facing the mounting member 5 is sealed with the seal member 10 fitted to the inner diameter surface of the cylindrical portion 5a of the mounting member 5 as shown in FIG. This is the same as the reference proposal example shown in FIG. Other configurations are the same as those of the reference proposal example of FIGS.
[0023]
Also in the case of this reference proposal example , since the conductive member 6 is brought into contact with the conductive ball 18 of the ball plunger 8C provided at the center of the rotating shaft 11 as a contact member, the peripheral speed of the contact portion is very small. Thus, the wear of the contact portion can be kept small. Further, when the rotary shaft 11 vibrates in the axial direction, the vibration can be absorbed by the conductive spring member 19 of the ball plunger 8C, so that the contact pressure of the conductive member 6 on the contact member 8C can be kept constant. .
[0024]
9 and 10 show still another reference proposal example of the present invention. The current bearing, in Reference proposed example shown in FIGS. 3 and 4, the attachment of the conductive member 6 to the mounting member 5, instead of the fastener 7 consisting of rivets, fastened to the bolts 15 and nuts 16 ing. Thereby, when the conductive member 6 is worn, it can be easily replaced. The end of the space between the inner and outer rings 1 and 2 facing the mounting member 5 is sealed with a seal member 10 fitted to the inner diameter surface of the cylindrical portion 5 a of the mounting member 5.
[0025]
11 and 12 show still another reference proposal example of the present invention. 5 and 6, this energizing bearing replaces the fixing of the conductive member 6 to the mounting member 5 with the bolts 15 and nuts 16 in the reference proposal example shown in FIGS. The conductive member 6 is fastened and fixed by screwing the bolt 21 into the female thread portion 5fa on the inner peripheral surface of the burring portion 5f formed in the above. Other configurations are the same as those of the reference proposal example of FIGS.
[0026]
In the case of this reference proposal example , since the conductive member 6 is fastened and fixed to the mounting member 5 with the bolt 21 screwed into the burring portion 5f of the mounting member 5, the conductive member 6 is mounted in a replaceable manner. The structure can be realized with a small number of parts, and the cost can be reduced and the assembly can be simplified.
[0027]
Incidentally, the energization bearing above you施形state and the reference example of proposed configuration, when the voltage difference unexpected between the inner and outer rings 1, 2 occurs, a current flows through the bypass circuit to avoid the rolling elements 3 The present invention is not limited to this case, and can also be applied to the case where the bypass circuit is used as a part of the energization path of a predetermined electric circuit.
[0028]
Although above you施形status and the references proposed example was assumed that the inner ring 1 rotates, it is assumed that the outer ring 2 rotates, the inner ring 2 may be those attached to a fixed shaft (not shown) .
[0029]
【The invention's effect】
The inventions of the current bearing, cylindrical portion fitted to the inner diameter surface of the outer ring has conductivity, and through a mounting member having a width surface contacting the flange portion of the outer ring, the conductive member having elasticity and conductivity Is attached to the outer ring, the tip of the conductive member is brought into contact with the surface facing the axial direction with respect to the conductive contact member attached to the inner ring, and the contact portion between the tip of the conductive member and the contact member The conductive member having elasticity and conductivity is a leaf spring or a coil spring, and the conductive contact member attached to the inner ring is ring-shaped, and the inner ring A cylindrical portion that fits to the outer diameter surface of the inner ring, and an annular band portion that extends from one end of the cylindrical portion to both the inner diameter side and the outer diameter side, and press-fits the cylindrical portion to the outer diameter surface of the inner ring. By bringing the inner diameter side portion of the annular belt portion into contact with the width surface of the inner ring The contact member is attached to the inner ring, and the lubricant inside the bearing is in contact with the attachment member and the contact member at the outer diameter side portion of the annular band portion of the contact member and the outward flange portion of the attachment member. Since the partition wall that prevents leakage to the part is formed, the electrical resistance between the inner and outer rings of the bearing can be reduced stably, and it is difficult for electric corrosion to occur on the rolling surface. It becomes possible to flow. In addition, since the conductive member attached to one raceway and the contact member attached to the other raceway are brought into contact with each other, compared to the case of providing one conductive member that contacts both raceways, It is easy to make contact at a position away from the rolling surface, and it is easy to avoid an increase in electrical resistance due to the inclusion of insulating sealed grease. Further, unlike the case where the conductive member is attached to the housing, the bearing itself is provided with the conductive member, so that assembly to the device is easy. When the conductive member is an elastic body, even if wear occurs, the contact resistance does not increase with time, and a current can flow more stably .
In the present invention, when thermally solidified grease is enclosed as a lubricant, an increase in electrical resistance due to the presence of grease can be avoided.
[Brief description of the drawings]
FIG. 1A is a cross-sectional view of an energized bearing according to an embodiment of the present invention, and FIGS. 1B and 1C are cross-sectional views of a mounting member and a contact member in the energized bearing.
2A is a cross-sectional view taken along line II in FIG. 1, FIG. 2B is a cross-sectional view taken along arrow II-II in FIG. 1A, and FIG. 2C is a plan view of a modification of the contact member;
FIG. 3 is a sectional view of a current-carrying bearing according to a reference proposal example of the present invention.
FIG. 4 is a front view of the energizing bearing.
FIG. 5 is a cross-sectional view of a current-carrying bearing according to another reference proposal example of the present invention.
FIG. 6 is a front view of the energizing bearing.
FIG. 7 is a cross-sectional view of a current-carrying bearing according to still another reference proposal example of the present invention.
FIG. 8 is a front view of the energizing bearing.
FIG. 9 is a cross-sectional view of a current-carrying bearing according to still another reference proposal example of the present invention.
FIG. 10 is a front view of the energizing bearing.
FIG. 11 is a cross-sectional view of a current-carrying bearing according to still another reference proposal example of the present invention.
FIG. 12 is a front view of the energizing bearing.
FIG. 13 is a front view of a conventional example.
[Explanation of symbols]
1 ... Inner ring (Raceway)
2 ... Outer ring (Raceway)
5 ... Mounting member 5a ... Cylindrical portion 5b ... Outward flange portion 5f ... Burring processing portion 5fa ... Female thread portion 6 ... Conductive members 8, 8A, 8B, 8C ... Contact members

Claims

Rolling bearings in which rolling elements are interposed between a pair of raceways that are respectively an inner ring and an outer ring, and a cylindrical portion that is electrically conductive and fits to the inner diameter surface of the outer ring, and a flange portion that contacts the width surface of the outer ring A conductive member having elasticity and conductivity is attached to the outer ring via a mounting member having a surface, and the tip of the conductive member faces in the axial direction with respect to the conductive contact member attached to the inner ring. A contact portion between the tip of the conductive member and the contact member is provided on the axially outer side of the bearing, and the conductive member having elasticity and conductivity is a leaf spring or a coil spring, and is connected to the inner ring. The attached conductive contact member is ring-shaped, and includes a cylindrical portion that fits to the outer diameter surface of the inner ring, and an annular band portion that extends from one end of the cylindrical portion to both the inner diameter side and the outer diameter side. The cylindrical part is pressed against the outer diameter surface of the inner ring. The contact member is attached to the inner ring by fitting and bringing the inner diameter side portion of the annular band portion into contact with the width surface of the inner ring, and the outer diameter side portion of the annular band portion of the contact member and the mounting member A current-carrying bearing characterized in that a partition wall that prevents the lubricant inside the bearing from leaking into the contact portion between the mounting member and the contact member is formed with the outward flange portion.

The current-carrying bearing according to claim 1, wherein thermally solidified grease is sealed between the pair of race rings.