JP3903516B2

JP3903516B2 - Current-carrying ball bearing

Info

Publication number: JP3903516B2
Application number: JP06133097A
Authority: JP
Inventors: 和孝山口; 英志渋谷
Original assignee: NSK Ltd
Current assignee: NSK Ltd
Priority date: 1997-03-14
Filing date: 1997-03-14
Publication date: 2007-04-11
Anticipated expiration: 2017-03-14
Also published as: JPH10252745A

Description

【０００１】
【発明の属する技術分野】
この発明に係る通電式玉軸受は、例えば自動車用操舵装置に組み込んで、金属製のステアリングシャフトを、金属製のステアリングコラムの内側に回転自在に支持する為に利用する。
【０００２】
【従来の技術】
自動車用操舵装置を構成するステアリングホイール部分には、警音器（ホーン）のスイッチを設ける必要上、電気配線を行なうが、この電気配線は、車体とは絶縁されたコード等を流れる回路と、車体を通じて流れるアース回路とから構成する。一方、上記ステアリングホイールを上端部に支持したステアリングシャフトは、車体に支持されたステアリングコラムの内側に、上下１対の玉軸受を介して、回転自在に支持している。ステアリングシャフトとステアリングコラムとが金属製である場合、上記玉軸受が上記アース回路の一部を構成するが、玉軸受を構成する玉に電流を流すと、この玉の転動面、並びに内外輪の軌道面が電気的に腐食する為、玉軸受の耐久性が損なわれてしまう。
【０００３】
この為従来から、実開昭６３−２８９２１号公報、実開平１−１３９１２３号公報、同４−８８５２５号公報、同６−１４５４７号公報、同６−１４５４８号公報等に記載された様な通電式玉軸受が、自動車用操舵装置等、電気が流れる部分に使用されていた。これら従来から知られている通電式玉軸受は、弾性を有する金属製の線材を、内輪の端部外周面並びに外輪の端部内周面に形成した凹溝に係止したり、或は合成樹脂製の保持器の一部に金属板を、この保持器を射出成形する際にインサートしている。これら従来構造の場合には、上記線材又は金属板が内輪と外輪とを電気的に導通させて、玉に電流が流れる事を防止し、この玉の転動面、並びに内外輪の軌道面が電気的に腐食する事を防止する。
【０００４】
【発明が解決しようとする課題】
上述の様な構造を有する従来の通電式玉軸受の場合、次の様な点を改良する事が望まれている。先ず、金属製の線材を内輪の端部外周面並びに外輪の端部内周面に形成した凹溝に係止する構造の場合、例えば軸受メーカーから自動車用操舵装置を組み立てる自動車メーカーに玉軸受を搬送する際に、この線材が外れる可能性があった。線材が外れた玉軸受を、気付かずにそのまま自動車用操舵装置に組み付けた場合、玉軸受の耐久性が損なわれる。又、線材が内輪と外輪との一方と共に回転し、他方に対して摺動する為、摺動部の滑り速度が速く（摺動部の単位時間当りの滑り量が多く）なり、摺動部の摩耗が進み易い。
【０００５】
これに対して、合成樹脂製の保持器の一部に金属板をインサートする構造の場合には、金属板付の合成樹脂製保持器の製造作業が面倒で、コストが嵩むだけでなく、通電式でない一般の玉軸受との間で保持器を共用できない。この為、通電式玉軸受専用の保持器が必要になり、部品の種類増加により、やはりコストが嵩む原因となる。
本発明の通電式玉軸受は、上述の様な不都合を何れも解消すべく、考えたものである。
【０００６】
【課題を解決するための手段】
本発明の通電式玉軸受は、従来から知られている通電式玉軸受と同様に、外周面に深溝型の内輪軌道を有する内輪と、内周面に深溝型の外輪軌道を有する外輪と、これら内輪軌道と外輪軌道との間に転動自在に設けられた複数の玉と、これら複数の玉を転動自在に保持する、合成樹脂製の保持器と、上記内輪と外輪とを電気的に導通させる通電部材とを備える。
【０００７】
特に、本発明の通電式玉軸受に於いては、上記通電部材は弾性を有する金属製の線材を曲げ形成する事により、中間部を略コ字形に形成すると共に、両端部に、上記内輪及び外輪の軸方向に関して同じ方向に折れ曲がって、更にそれぞれの先端部がこれら内輪及び外輪の円周方向に向けて折れ曲がった、１対の係止部を設けたものであり、上記保持器の一部で円周方向に離れた２個所位置に、この保持器の軸方向端面側に通じる入口部と、この入口部の奥端からこの保持器の円周方向に向け折れ曲がった折れ曲がり部とを備えた断面Ｌ字形で、この保持器の軸方向端面及びこの保持器の内外両周面に開口して、上記通電部材の一部を係脱自在な係止切り欠きを、この保持器の直径方向に亙り形成している。そして、これら両係止切り欠きに上記両係止部を係合した状態で上記通電部材の中間部は、上記内輪の外周面の一部で上記内輪軌道から外れた部分と上記外輪の内周面の一部で上記外輪軌道から外れた部分とに弾性的に当接している。
【０００８】
【作用】
上述の様に構成される本発明の通電式玉軸受の場合、内輪と外輪とは通電部材により電気的に導通されており、外輪と内輪との間で流れる電流の大部分は、電気抵抗の小さな上記通電部材を通る。この為、玉を流れる電流は僅少となり、玉の転動面や内外輪の軌道面に電気的な腐食が生じる事がなくなる。又、上記通電部材は保持器と共に回転するので、この通電部材と内輪及び外輪との摺動部の滑り速度は、これら内輪と外輪との相対速度の半分程度になる。従って、上記摺動部の摩耗を少なく抑えて、通電式玉軸受の性能を安定させると共に耐久性向上を図れる。
【０００９】
又、上記通電部材は、その両端部に形成した１対の係止部を、合成樹脂製の保持器に形成した１対の係止切り欠きに係合させる事により保持器に装着するので、この保持器の製作が面倒になる事がない。又、この保持器は、上記両係止切り欠きに上記通電部材の両端部に設けた１対の係止部を係合させなければ、通電式でない一般の玉軸受用の保持器として利用できる。
【００１０】
【発明の実施の形態】
図１〜２は、本発明に関する参考例の１例を示している。外周面に深溝型の内輪軌道１を有する内輪２と、内周面に深溝型の外輪軌道３を有する外輪４とを同心に配置している。そして、上記内輪軌道１と外輪軌道３との間に複数の玉５、５を、転動自在に設けている。これら複数の玉５、５は、合成樹脂を射出成形する事により一体成形した保持器６により、転動自在に保持している。図示の例では、この保持器６として、冠型の保持器６を使用している。この冠型の保持器６は、円環状の基部７の軸方向片面（図１の裏面、図２の上面）に、部分円筒面状若しくは部分球面状の凹部８、８を形成すると共に、これら各凹部８、８の開口縁部にそれぞれ弾性爪片９、９を設け、これら凹部８、８及び弾性爪片９、９により囲まれる部分をポケット１０、１０としている。上記各玉５、５は、上記各弾性爪片９、９の先端同士の間隔を弾性的に広げた状態で、上記各ポケット１０、１０内に押し込む。そして、押し込んだ状態で上記各玉５、５は上記各ポケット１０、１０内に、転動自在に保持される。
【００１１】
本参考例の通電式玉軸受の場合には、上記保持器６を構成する基部７の軸方向他面（図１の表面、図２の下面）の一部に係止切り欠き１１を形成し、この係止切り欠き１１に、通電部材１２の中間部に形成した係止部１３を係合させている。上記係止切り欠き１１は、上記基部７の直径方向に亙り形成し、上記軸方向他端面の他、上記基部７の内外両周面に開口している。この様な係止切り欠き１１は、円筒面状の奥部１４と、この奥部１４から連続し、上記基部７の軸方向他端面側の開口部分に形成した開口部１５とから成る。この開口部１５は、上記奥部１４の内径Ｒ₁₄よりも小さな幅寸法Ｗ₁₅を有する。
【００１２】
一方、上記通電部材１２は、ステンレスのばね鋼等、弾性を有する金属製の線材を曲げ形成する事により形成したもので、中間部に上記係止部１３を有する。この係止部１３は、上記線材を円形に湾曲させて成る先端部１６と、この先端部から連続する基部１７とを備える。このうちの先端部１６の外径Ｄ₁₆は、上記係止切り欠き１１を構成する開口部１５の幅寸法Ｗ₁₅よりも大きく、奥部１４の内径Ｒ₁₄とほぼ同じ（Ｗ₁₅＜Ｄ₁₆≒Ｒ₁₄）としている。又、上記通電部材１２の両側部分は大きく湾曲させて、導通部１８、１８としている。
【００１３】
上述の様な通電部材１２は、上記各導通部１８、１８を、曲率半径を大きくする方向に弾性変形させつつ、前記内輪２の端部外周面と外輪４の端部内周面との間の環状空間１９内に挿入する。挿入後、上記各導通部１８、１８に付与していた力を解除すれば、これら各導通部１８、１８が、曲率半径を小さくする方向に弾性的に復元する。この結果、これら各導通部１８、１８が、図１に示す様に、上記内輪２の端部外周面で前記内輪軌道１から外れた部分と、上記外輪４の端部内周面で前記外輪軌道３から外れた部分とに弾性的に当接する。
【００１４】
尚、上記保持器６側の係止切り欠き１１と通電部材１２側の係止部１３とを係合させる作業は、上記保持器６を玉軸受に組み込む以前に行なっても、或はこの保持器６を玉軸受に組み込んだ後に行なっても良い。組み込む以前に行なう際には、上記係止部１３を上記係止切り欠き１１に、上記保持器６の外径側開口又は内径側開口から挿入する。そして、通電部材１２を結合した保持器６を、上記環状空間１９内に押し込む。この際、前記各弾性爪片９、９は、弾性変形しつつ、前記各玉５、５が前記各ポケット１０、１０内に進入する事を許容する。又、組み付け後に行なう場合には、上記係止部１３の先端部１６と上記係止切り欠き１１の開口部１５との一方又は双方が弾性変形しつつ、上記先端部１６が開口部１５を通過する事を許容する。そして、通過後は弾性的に復元して、上記係止部１３が上記係止切り欠き１１から抜け出る事を阻止する。尚、保持器６の基部７の内周面と内輪２の端部外周面との間、又はこの基部７の外周面と外輪４の端部内周面との間に、上記係止部１３を挿入できるだけの隙間が存在すれば、上記保持器６を玉軸受に組み込んだ後、上記係止部１３を上記係止切り欠き１１に、上記基部７の内周面側の開口又は外周面側の開口から係合させる事もできる。
【００１５】
上述の様に構成される本参考例の通電式玉軸受の場合、上記内輪２と外輪４とは、通電部材１２を構成する１対の導通部１８、１８により電気的に導通されている。これら各導通部１８、１８と内輪２の端部外周面及び外輪４の端部内周面との間には、グリース等の潤滑剤が存在しないか、仮に存在しても極く僅かである。従って、これら各導通部１８、１８と内輪２の外周面及び外輪４の内周面との当接部の電気抵抗は小さい。これに対して、前記各玉５、５の転動面と前記内輪軌道１及び外輪軌道３との間には、グリース等の潤滑剤の膜が存在する。従って、これら各玉５、５の転動面と前記内輪軌道１及び外輪軌道３との当接部の電気抵抗は比較的大きい。従って、上記外輪４と内輪２との間で流れる電流の大部分は、上記通電部材１２を構成する１対の導通部１８、１８を通る。この為、上記各玉５、５を流れる電流は僅少となり、これら各玉５、５の転動面や、上記内輪軌道１及び外輪軌道３に電気的な腐食が生じる事がなくなる。
【００１６】
又、上記通電部材１２は保持器６と共に回転するので、この通電部材１２を構成する１対の導通部１８、１８と上記内輪２の端部外周面及び外輪４の端部内周面との摺動部の滑り速度（各当接部の単位時間当りの滑り量）は、これら内輪２と外輪４との相対速度の半分程度になる。従って、上記各摺動部の摩耗を少なく抑えて、通電式玉軸受の性能を安定させると共に耐久性向上を図れる。
【００１７】
又、上記通電部材１２は、その中央部に形成した係止部１３を、合成樹脂製の保持器６に形成した係止切り欠き１１に係合させる事により、この保持器６に装着するので、この保持器６の製作が面倒になる事がない。即ち、本参考例の通電式玉軸受を構成する保持器６は、上記係止切り欠き１１を設けた以外、一般的な冠型保持器と同様である。又、この係止切り欠き１１は、合成樹脂を射出成形する事により、前記各ポケット１０、１０を形成するのと同時に形成する事ができる。従って、上記保持器６のコストが嵩む事はない。
【００１８】
更に、この保持器６に設けた上記係止切り欠き１１と、上記通電部材１２に設けた上記係止部１３とを係合させた後は、これら係止切り欠き１１と係止部１３とが不用意に外れる事はない。従って、搬送中に上記通電部材１２が外れる事がなく、通電部材１２が外れた玉軸受を組み込む事でこの玉軸受の耐久性を損なう事がない。更に、上記保持器６は、上記係止切り欠き１１に上記通電部材１２の係止部１３を係合させなければ、通電式でない一般の玉軸受用の保持器として利用できる。従って、通電式でない一般の玉軸受との間で保持器を共用できる。この為、通電式玉軸受専用の保持器が不要になり、部品の種類増加を抑えて、やはり通電式玉軸受のコストが嵩む事を防止できる。
【００１９】
次に、図３〜４は、本発明の実施の形態の１例を示している。本例の場合には、保持器６の軸方向端面である、この保持器６を構成する基部７の軸方向他面（図３の表面、図４の下面）の一部で円周方向に離れた２個所位置に、それぞれ係止切り欠き１１ａ、１１ａを形成している。そして、これら両係止切り欠き１１ａ、１１ａに、通電部材１２ａの両端部に形成した係止部１３ａ、１３ａを係合させている。上記両係止切り欠き１１ａ、１１ａは、上記基部７の直径方向に亙り形成し、上記軸方向他端面の他、上記基部７の内外両周面に開口している。これら各係止切り欠き１１ａ、１１ａは、それぞれ断面Ｌ字形に形成したもので、上記基部７の軸方向他端面側に通じる入口部２０と、この入口部２０の奥端から円周方向に向け直角に折れ曲がった折れ曲がり部２１とから成る。
【００２０】
一方、上記通電部材１２ａは、ステンレスのばね鋼等、弾性を有する金属製の線材を曲げ形成する事により形成したもので、両端部に上記係止部１３ａ、１３ａを形成している。これら両係止部１３ａ、１３ａは、上記線材の両端部を、内輪２及び外輪４の軸方向（図３の表裏方向、図４の上下方向）に関して同じ方向に折り曲げて成る。更に、上記両係止部１３ａ、１３ａの先端部は、それぞれ上記各係止切り欠き１１ａ、１１ａの折れ曲がり部２１と同じ方向に直角に折り曲げて、上記両係止部１３ａ、１３ａをＬ字形に形成している。又、上記通電部材１２ａの中間部は、略コ字形に曲げ形成して成り、両端部に形成した上記両係止部１３ａ、１３ａ同士の距離を近づけ合う方向の弾力を付与している。
【００２１】
上述の様な通電部材１２ａは、上記両係止部１３ａ、１３ａを上記両係止切り欠き１１ａ、１１ａに係止した状態で、上記保持器６と共に、内輪２の端部外周面と外輪４の端部内周面との間の環状空間１９内に挿入する。この挿入作業の間、上記通電部材１２ａに、この通電部材１２ａの中間部２個所位置に設けた湾曲部２２、２２の曲率半径を大きくする方向の力を付与しておく。そして、挿入後にこの力を解除すれば、上記各湾曲部２２、２２が、曲率半径を小さくする方向に弾性的に復元する。この結果、図３に示す様に、これら各湾曲部２２、２２の外周縁が上記外輪の端部内周面で外輪軌道３から外れた部分に、これら各湾曲部２２、２２と上記各係止部１３ａ、１３ａとの間部分の内周縁が上記内輪２の端部外周面に、それぞれ弾性的に当接する。上記係止切り欠き１１ａ、１１ａ及び係止部１３ａ、１３ａの形状が第１例の場合とは異なった事に伴い、これら係止切り欠き１１ａ、１１ａと係止部１３ａ、１３ａとの係合を、保持器６の基部７の外周面側開口又は内周面側開口からしか行なえない以外の構成及び作用は、前述した参考例の場合とほぼ同様である。
【００２２】
【発明の効果】
本発明は、以上に述べた通り構成され作用する為、安価でしかも優れた耐久性及び信頼性を備え、しかも低トルクの通電式玉軸受を実現できる。
【図面の簡単な説明】
【図１】本発明に関する参考例の１例を示す正面図。
【図２】この参考例に組み込む保持器及び通電部材のみを取り出して分解し、その一部を図１の上方から見た図。
【図３】本発明の実施の形態の１例を示す正面図。
【図４】この実施の形態の１例に組み込む保持器及び通電部材のみを取り出して分解し、その一部を図３のＡ矢視方向から見た図。
【符号の説明】
１内輪軌道
２内輪
３外輪軌道
４外輪
５玉
６保持器
７基部
８凹部
９弾性爪片
１０ポケット
１１、１１ａ係止切り欠き
１２、１２ａ通電部材
１３、１３ａ係止部
１４奥部
１５開口部
１６先端部
１７基部
１８導通部
１９環状空間
２０入口部
２１折れ曲がり部
２２湾曲部 [0001]
BACKGROUND OF THE INVENTION
The energizing ball bearing according to the present invention is incorporated in, for example, an automobile steering device, and is used to rotatably support a metal steering shaft inside a metal steering column.
[0002]
[Prior art]
On the steering wheel portion constituting the automobile steering device, an electrical wiring is performed because it is necessary to provide a switch of a horn, and this electrical wiring is a circuit that flows through a cord or the like that is insulated from the vehicle body, It consists of an earth circuit that flows through the car body. On the other hand, a steering shaft that supports the steering wheel at its upper end is rotatably supported via a pair of upper and lower ball bearings inside a steering column supported by the vehicle body. When the steering shaft and the steering column are made of metal, the ball bearing constitutes a part of the earth circuit. When a current is passed through the ball constituting the ball bearing, the rolling surface of the ball and the inner and outer rings As a result, the durability of the ball bearing is impaired.
[0003]
For this reason, the current supply as described in Japanese Utility Model Laid-Open Nos. 63-28921, 1-139123, 4-88525, 6-14547, 6-14548, etc. Type ball bearings have been used in parts where electricity flows, such as automobile steering systems. These conventionally known energized ball bearings are made by locking an elastic metal wire rod into the outer circumferential surface of the inner ring end and the inner circumferential surface of the outer ring end, or synthetic resin. A metal plate is inserted into a part of the cage made of metal and is inserted when the cage is injection molded. In the case of these conventional structures, the wire or metal plate electrically connects the inner ring and the outer ring to prevent a current from flowing through the ball, and the rolling surface of the ball and the raceway surface of the inner and outer rings Prevents electrical corrosion.
[0004]
[Problems to be solved by the invention]
In the case of a conventional energized ball bearing having the above-described structure, it is desired to improve the following points. First, in the case of a structure in which a metal wire is locked in a groove formed in the outer peripheral surface of the end of the inner ring and the inner peripheral surface of the end of the outer ring, for example, a ball bearing is transported from a bearing manufacturer to an automobile manufacturer that assembles an automobile steering device. When doing this, there was a possibility that this wire would come off. When the ball bearing from which the wire has been detached is assembled in an automobile steering device without being noticed, the durability of the ball bearing is impaired. In addition, since the wire rotates together with one of the inner ring and the outer ring and slides with respect to the other, the sliding speed of the sliding part is high (the sliding part has a large sliding amount per unit time), and the sliding part Easier to wear.
[0005]
On the other hand, in the case of a structure in which a metal plate is inserted into a part of a synthetic resin cage, the manufacturing work of the synthetic resin cage with the metal plate is troublesome and not only increases the cost, but also energized. The cage cannot be shared with general ball bearings that are not. For this reason, a dedicated cage for the current-carrying ball bearing is required, and the increase in the types of parts also causes an increase in cost.
The energizing ball bearing of the present invention has been conceived to eliminate any of the above-mentioned disadvantages.
[0006]
[Means for Solving the Problems]
The current-carrying ball bearing of the present invention is an inner ring having a deep groove type inner ring raceway on the outer peripheral surface, and an outer ring having a deep groove type outer ring raceway on the inner peripheral surface, as in the case of conventionally known current-carrying ball bearings, a plurality of balls disposed rollably between these inner raceway and the outer ring raceway, to hold a plurality of balls rollably, electrical and steel cage synthetic resin, and the inner ring and the outer ring And a current-carrying member that conducts to.
[0007]
In particular, in the current-carrying ball bearing of the present invention, the current-carrying member is formed by bending a metal wire having elasticity to form an intermediate portion in a substantially U-shape, and at both ends, the inner ring and A part of the above cage is provided with a pair of locking parts bent in the same direction with respect to the axial direction of the outer ring, and further, each tip part being bent toward the circumferential direction of the inner ring and the outer ring. And provided at two positions separated in the circumferential direction by an inlet portion that leads to the axial end face side of the cage, and a bent portion that is bent from the back end of the inlet portion toward the circumferential direction of the cage. An L-shaped cross-section that opens in the axial end face of the cage and both the inner and outer peripheral surfaces of the cage, and has a locking notch that allows a part of the energizing member to be engaged and disengaged in the diameter direction of the cage. It is forming a resentment . The intermediate portion of the current-carrying member in a state where the both locking portions are engaged with the both locking notches is a part of the outer peripheral surface of the inner ring that is out of the inner ring raceway and the inner periphery of the outer ring. Part of the surface is elastically in contact with a portion deviated from the outer ring raceway.
[0008]
[Action]
In the case of the current-carrying ball bearing of the present invention configured as described above, the inner ring and the outer ring are electrically connected by the current-carrying member, and most of the current flowing between the outer ring and the inner ring is the electric resistance. It passes through the small current-carrying member. For this reason, the current flowing through the ball becomes very small, and electrical corrosion does not occur on the rolling surface of the ball and the raceway surface of the inner and outer rings. Further, since the energizing member rotates together with the cage, the sliding speed of the sliding portion between the energizing member and the inner ring and the outer ring is about half of the relative speed between the inner ring and the outer ring. Therefore, the wear of the sliding portion can be suppressed to a low level, the performance of the energizing ball bearing can be stabilized and the durability can be improved.
[0009]
In addition, the current-carrying member is attached to the cage by engaging a pair of locking portions formed on both ends thereof with a pair of locking notches formed on the synthetic resin cage. The production of this cage is not troublesome. Further, this cage can be used as a cage for general ball bearings that are not energized unless a pair of locking portions provided at both ends of the current-carrying member are engaged with the both locking notches. .
[0010]
DETAILED DESCRIPTION OF THE INVENTION
1 and 2 show an example of a reference example related to the present invention . An inner ring 2 having a deep groove type inner ring raceway 1 on an outer peripheral surface and an outer ring 4 having a deep groove type outer ring raceway 3 on an inner peripheral surface are arranged concentrically. A plurality of balls 5 and 5 are provided between the inner ring raceway 1 and the outer ring raceway 3 so as to roll freely. The plurality of balls 5 and 5 are rotatably held by a cage 6 that is integrally formed by injection molding of synthetic resin. In the illustrated example, a crown-shaped cage 6 is used as the cage 6. The crown-shaped cage 6 is formed with concave portions 8 and 8 having a partial cylindrical surface shape or a partial spherical shape on one axial surface (the rear surface in FIG. 1 and the upper surface in FIG. 2) of the annular base portion 7. Elastic claw pieces 9 and 9 are provided at the opening edge portions of the respective concave portions 8 and 8, and portions surrounded by the concave portions 8 and 8 and the elastic claw pieces 9 and 9 are formed as pockets 10 and 10. The balls 5 and 5 are pushed into the pockets 10 and 10 in a state where the distance between the tips of the elastic claw pieces 9 and 9 is elastically widened. The balls 5 and 5 are held in the pockets 10 and 10 so that they can roll.
[0011]
In the case of the current-carrying ball bearing of this reference example , a locking notch 11 is formed on a part of the other axial surface (the front surface in FIG. 1 and the lower surface in FIG. 2) of the base 7 constituting the cage 6. The engaging notch 11 is engaged with an engaging portion 13 formed at the intermediate portion of the energizing member 12. The locking notches 11 are formed so as to extend in the diameter direction of the base portion 7 and open to both the inner and outer peripheral surfaces of the base portion 7 in addition to the other axial end surface. Such a locking notch 11 comprises a cylindrical surface-like back portion 14 and an opening portion 15 that is continuous from the back portion 14 and is formed in an opening portion on the other end surface side in the axial direction of the base portion 7. The opening 15 has a width dimension W ₁₅ smaller than the inner diameter R ₁₄ of the inner portion 14.
[0012]
On the other hand, the energizing member 12 is formed by bending a metal wire having elasticity, such as stainless spring steel, and has the locking portion 13 in an intermediate portion. The locking portion 13 includes a distal end portion 16 formed by bending the wire rod into a circle and a base portion 17 continuous from the distal end portion. The outer diameter D ₁₆ of the tip portion 16 is larger than the width dimension W ₁₅ of the opening 15 constituting the locking notch 11 and is substantially the same as the inner diameter R ₁₄ of the inner portion 14 (W ₁₅ <D ₁₆ ≒ is set to R _14). Further, both side portions of the energizing member 12 are largely curved to form conductive portions 18 and 18.
[0013]
The energizing member 12 as described above is formed between the end outer peripheral surface of the inner ring 2 and the inner peripheral surface of the end of the outer ring 4 while elastically deforming the conductive portions 18 and 18 in the direction of increasing the radius of curvature. It is inserted into the annular space 19. After the insertion, when the force applied to each of the conductive portions 18 and 18 is released, each of the conductive portions 18 and 18 is elastically restored in the direction of decreasing the radius of curvature. As a result, as shown in FIG. 1, these conductive portions 18 and 18 are connected to the outer ring raceway at the end outer peripheral surface of the inner ring 2 and the outer ring raceway at the end inner peripheral surface of the outer ring 4. 3 is elastically abutted against a portion deviated from 3.
[0014]
Note that the operation of engaging the locking notch 11 on the cage 6 side with the locking portion 13 on the current-carrying member 12 side may be performed before the cage 6 is incorporated in the ball bearing or this holding. It may be performed after the device 6 is incorporated in the ball bearing. When it is performed before assembly, the locking portion 13 is inserted into the locking notch 11 from the outer diameter side opening or the inner diameter side opening of the cage 6. Then, the cage 6 to which the energizing member 12 is coupled is pushed into the annular space 19. At this time, the elastic claw pieces 9 and 9 allow the balls 5 and 5 to enter the pockets 10 and 10 while being elastically deformed. Further, when it is performed after the assembly, one or both of the distal end portion 16 of the locking portion 13 and the opening portion 15 of the locking notch 11 is elastically deformed, and the distal end portion 16 passes through the opening portion 15. Allow to do. And after passing, it elastically restores and prevents the locking part 13 from coming out of the locking notch 11. In addition, between the inner peripheral surface of the base portion 7 of the cage 6 and the outer peripheral surface of the end portion of the inner ring 2, or between the outer peripheral surface of the base portion 7 and the inner peripheral surface of the end portion of the outer ring 4, If there is a gap that can be inserted, after the cage 6 is incorporated in the ball bearing, the locking portion 13 is inserted into the locking notch 11 and the opening on the inner peripheral surface side of the base portion 7 or on the outer peripheral surface side. It can also be engaged from the opening.
[0015]
In the case of the energizing ball bearing of this reference example configured as described above, the inner ring 2 and the outer ring 4 are electrically connected by a pair of conducting portions 18, 18 constituting the energizing member 12. A lubricant such as grease is not present between the conductive portions 18 and 18 and the outer peripheral surface of the end of the inner ring 2 and the inner peripheral surface of the end of the outer ring 4. Therefore, the electrical resistance of the contact portion between each of the conductive portions 18 and 18 and the outer peripheral surface of the inner ring 2 and the inner peripheral surface of the outer ring 4 is small. On the other hand, a lubricant film such as grease exists between the rolling surfaces of the balls 5 and 5 and the inner ring raceway 1 and the outer ring raceway 3. Therefore, the electrical resistance of the contact portion between the rolling surfaces of the balls 5 and 5 and the inner ring raceway 1 and the outer ring raceway 3 is relatively large. Therefore, most of the current flowing between the outer ring 4 and the inner ring 2 passes through the pair of conducting portions 18 and 18 constituting the energizing member 12. For this reason, the current flowing through the balls 5 and 5 is small, and electrical corrosion does not occur on the rolling surfaces of the balls 5 and 5 and the inner ring raceway 1 and the outer ring raceway 3.
[0016]
Further, since the energizing member 12 rotates together with the cage 6, the sliding between the pair of conducting portions 18, 18 constituting the energizing member 12 and the outer peripheral surface of the end portion of the inner ring 2 and the inner peripheral surface of the end portion of the outer ring 4. The sliding speed of the moving part (slip amount per unit time of each contact part) is about half of the relative speed between the inner ring 2 and the outer ring 4. Therefore, it is possible to suppress the wear of each sliding portion as described above, stabilize the performance of the energizing ball bearing, and improve the durability.
[0017]
The energizing member 12 is attached to the retainer 6 by engaging the engaging portion 13 formed in the central portion thereof with the engaging notch 11 formed in the retainer 6 made of synthetic resin. The production of the cage 6 is not troublesome. That is, the cage 6 constituting the energization type ball bearing of this reference example is the same as a general crown type cage except that the above-mentioned locking notch 11 is provided. Further, the locking notch 11 can be formed at the same time as the pockets 10 and 10 are formed by injection molding synthetic resin. Therefore, the cost of the cage 6 does not increase.
[0018]
Further, after engaging the locking notch 11 provided on the cage 6 with the locking portion 13 provided on the energizing member 12, the locking notch 11 and the locking portion 13 Will not come off carelessly. Therefore, the current-carrying member 12 is not detached during conveyance, and the durability of the ball bearing is not impaired by incorporating the ball bearing from which the current-carrying member 12 is removed. Further, the retainer 6 can be used as a retainer for a general ball bearing that is not energized unless the retaining portion 13 of the energizing member 12 is engaged with the retaining notch 11. Therefore, the cage can be shared with a general ball bearing that is not energized. This eliminates the need for a dedicated cage for the current-carrying ball bearing, suppresses an increase in the number of types of components, and prevents an increase in the cost of the current-carrying ball bearing.
[0019]
Next, FIGS. 3 to 4 show an example of an embodiment of the present invention. In the case of this example, a part of the other axial surface of the base 7 constituting the retainer 6 (the front surface in FIG. 3 and the bottom surface in FIG. 4), which is the axial end surface of the retainer 6 , extends in the circumferential direction. Locking notches 11a and 11a are formed at two positions apart from each other. And the latching | locking part 13a, 13a formed in the both ends of the electricity supply member 12a is engaged with these both latching notches 11a and 11a. Both the locking notches 11a and 11a are formed so as to extend in the diameter direction of the base portion 7 and open to both inner and outer peripheral surfaces of the base portion 7 in addition to the other axial end surface. Each of the locking notches 11a and 11a is formed in an L-shaped cross section. The inlet 20 communicates with the other end surface in the axial direction of the base 7, and the circumferential direction extends from the back end of the inlet 20 to the circumferential direction. It consists of a bent portion 21 bent at a right angle.
[0020]
On the other hand, the energizing member 12a is formed by bending a metal wire having elasticity, such as stainless spring steel, and the locking portions 13a and 13a are formed at both ends. Both the locking portions 13a and 13a are formed by bending both ends of the wire in the same direction with respect to the axial direction of the inner ring 2 and the outer ring 4 (the front and back direction in FIG. 3 and the vertical direction in FIG. 4). Further, the front ends of the locking portions 13a and 13a are bent at right angles in the same direction as the bent portions 21 of the locking notches 11a and 11a , respectively, so that the locking portions 13a and 13a are L-shaped. Forming . Further, the middle portion of the energizing member 12a is formed by bending it into a substantially U shape, and provides elasticity in the direction in which the distance between the locking portions 13a, 13a formed at both ends is made closer.
[0021]
The current-carrying member 12a as described above, together with the retainer 6, the outer peripheral surface of the end portion of the inner ring 2 and the outer ring 4 in a state where the engaging portions 13a, 13a are engaged with the engaging notches 11a, 11a. It inserts in the annular space 19 between the edge part inner peripheral surfaces. During this insertion operation, a force is applied to the energizing member 12a in the direction of increasing the radius of curvature of the curved portions 22 and 22 provided at two positions in the middle of the energizing member 12a. And if this force is cancelled | released after insertion, each said curved part 22 and 22 will restore | restore elastically in the direction which makes a curvature radius small. As a result, as shown in FIG. 3, the curved portions 22, 22 and the locking portions of the curved portions 22, 22 are separated from the outer ring raceway 3 on the inner circumferential surface of the end portion of the outer ring. The inner peripheral edge of the portion between the portions 13a and 13a elastically contacts the outer peripheral surface of the end portion of the inner ring 2 respectively. Since the shapes of the locking notches 11a and 11a and the locking portions 13a and 13a are different from those of the first example, the locking notches 11a and 11a are engaged with the locking portions 13a and 13a. The configuration and operation other than that which can be performed only from the outer peripheral surface side opening or the inner peripheral surface side opening of the base portion 7 of the cage 6 are substantially the same as those in the above-described reference example .
[0022]
【The invention's effect】
Since the present invention is configured and operates as described above, it is possible to realize a low-torque energized ball bearing that is inexpensive and has excellent durability and reliability.
[Brief description of the drawings]
FIG. 1 is a front view showing an example of a reference example related to the present invention .
FIG. 2 is a view of only a cage and a current-carrying member incorporated in this reference example , taken out and disassembled, and a part thereof as seen from above in FIG.
FIG. 3 is a front view showing an example of an embodiment of the present invention.
FIG. 4 is a view in which only a cage and an energizing member incorporated in an example of this embodiment are taken out and disassembled, and a part thereof is viewed from the direction of arrow A in FIG. 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Inner ring raceway 2 Inner ring 3 Outer ring raceway 4 Outer ring 5 Ball 6 Cage 7 Base part 8 Recessed part 9 Elastic claw piece 10 Pocket 11, 11a Engagement notch 12, 12a Energizing member 13, 13a Engagement part 14 Back part 15 Opening part 16 Tip 17 Base
18 conduction part 19 annular space 20 inlet part 21 bent part 22 curved part

Claims

An inner ring having an inner ring raceway of the deep groove on the outer peripheral surface, an outer ring having an inner circumferential surface the outer ring raceway of the deep groove type, a plurality of balls disposed rollably between these inner raceway and the outer ring raceway, these holding a plurality of balls rollably, and made of retainer synthetic resin, in the current type ball bearing that includes a conductive member for electrically connecting the inner ring and the outer ring, the conducting member is an elastic By bending the metal wire rod having the intermediate portion, the intermediate portion is formed in a substantially U shape, and the both ends are bent in the same direction with respect to the axial direction of the inner ring and the outer ring, and the respective tip portions are further A pair of locking portions bent in the circumferential direction of the outer ring are provided , and the axial end face side of the cage is located at two positions separated in the circumferential direction by a part of the cage. And the cage from the back end of the inlet. In an L-shaped cross section with a bent bent portion toward the circumferential direction, open to the inner and outer peripheral surfaces of the axial end face and the retainer of the retainer, disengage freely engaging the portion of the energizing member A notch is formed in the diametrical direction of the cage, and the intermediate portion of the energizing member is formed on the outer peripheral surface of the inner ring in a state where the both locking portions are engaged with the both locking notches . A current-carrying ball bearing characterized in that it is elastically in contact with a part of the outer ring that is partly disengaged from the inner ring raceway and a part of the inner ring of the outer ring that is partly disengaged from the outer ring raceway.