JP2004036863A - Double row rolling bearing with sensor unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize structure that can accurately detect a plurality of states of a double row rolling bearing 1 such as vibration and temperature in addition to rotating speed. <P>SOLUTION: A detected ring 10c is directly fitted and fixed to the outer peripheral surface of a hub 22 constituting an inner ring having double rows of inner ring raceway tracks 6, 6 on the outer peripheral surface together with an inner ring element 18. A sensor unit 31 is supported to an outer ring 5 provided around the hub 22. Sensors such as a temperature sensor and an acceleration sensor for measuring vibration in addition to a rotation detecting sensor are held to the sensor unit 31. <P>COPYRIGHT: (C)2004,JPO

Description

この表１から、上記厚さ寸法Ｔ_３９ａ　を上記凹凸の高さの１／４〜３倍の範囲に規制すれば、前記回転速度検出の性能を確保すると共に、複列転がり軸受１ａの組み付け性を良好にできる事が分かる。
【００２７】
これに対して上記温度センサ２１ｂは、前記ホルダ４０ｄの一部外周面寄り部分に支持している。この温度センサ２１ｂを支持する位置は、極力上記カバー９ａに近く、外輪５ａからこのカバー９ａに伝わる熱の影響を受け易い部分としている。尚、上記温度センサ２１ｂの温度検出性能を向上させる為には、上記ホルダ４０ｄの熱伝導率が良い事、及び、このホルダ４０ｄの温度が短時間で周囲温度に達する様にする為に、このホルダ４０ｄの熱容量が小さい事が必要である。
【００２８】
従って、このホルダ４０ｄの材質としては、熱伝導率が大きく、単位体積当たり熱容量（＝密度×比熱）が小さいものが適している。具体的には、上記ホルダ４０ｄの材質として、強度及びコスト上の問題がなければ、上記各特性を有する、アルミニウム、マグネシウム、銅、亜鉛等や、これらの合金を使用する事が望ましい。又、上記外輪５ａから上記温度センサ２１ｂにまで熱が伝わり易くする為に、軸受箱１２、カバー９ａに就いても、強度及びコスト上の問題がなければ、これらの材質を使用する事が望ましい。強度上の問題がある場合は、ステンレス鋼製としても良いが、上記ホルダ４０ｄに関しては、ステンレス鋼製とする場合でも、非磁性を有するものを使用する。この理由は、上記ホルダ４０ｄを磁性材製とすると、このホルダ４０ｄの磁性が前記回転検出センサ３ｅにより回転速度を測定する事に対する妨げとなり、この回転速度を正確に測定する事が難しくなる為である。この為、上記ホルダ４０ｄの材質としては、非磁性材が好ましい。
【００２９】
上述の様なセンサユニット３１ｇは、上記センサ取付孔４６ａ内に前記円筒部１９ａの径方向外方から内方に挿通した状態で、外周面に設けた取付フランジ３５を上記円筒部１９ａの外周面に、ボルト４７、４７により結合固定する。この状態で、このセンサユニット３１ｇの先端面に存在する上記回転検出センサ３ｅの検出部が、上記鍔部４５の外周縁に設けた被検出部に、前記隙間３９ａを介して近接対向する。又、上記温度センサ２１ｂは、上記カバー９ａの円筒部１９ａに、上記ホルダ４０ｄの一部を介して近接対向する。上記回転検出センサ３ｅの出力信号を取り出す為のハーネスと上記温度センサ２１ｂの出力を取り出す為のハーネスとは、一緒に束ねて１本のケーブル４８とし、図示しない制御器に接続する。又、上記ホルダ４０ｄの一部外周面と上記センサ取付孔４６ａの内周面との間にＯリング３４ａを装着して、これら両周面の間部分を通じて泥水等の異物が外部から進入するのを防止している。従って、上記上記センサユニット３１ｇは、上記カバー９ａにより外部と遮断された空間内に支持された状態となる。
【００３０】
上述の様に本例のセンサユニット付複列転がり軸受の場合には、単一のホルダ４０ｄに上記回転検出センサ３ｅと上記温度センサ２１ｂとを保持している為、これら両センサ３ｅ、２１ｂの取り付けスペースを小さくできる。しかも、これら両センサ３ｅ、２１ｂの取り付け作業が容易になる。又、これら両センサ３ｅ、２１ｂの出力信号を取り出す為のハーネスを一緒に束ねて１本のケーブル４８としている為、上記両センサ３ｅ、２１ｂの信号を取り出す為のハーネスの取り回しも容易になる。更に、本例の場合には、上記センサユニット３１ｇを、軸受箱１２の開口部に着脱自在に設けるカバー９ａに支持している為、保守・点検作業等の為に、このセンサユニット３１ｇを着脱する作業を容易に行なえる。
【００３１】
尚、上記１本のケーブル４８内には、上記回転検出センサ３ｅの出力信号を取り出す為のハーネスと、上記温度センサ２１ｂの出力信号を取り出す為のハーネスとを納めているが、これら各ハーネスは個別にシールドしている。この様に複数本のハーネスを束ねて１本のケーブル４８とする場合でも、それぞれのハーネスを個別にシールドする事により、各ハーネスを流れる信号電流同士が干渉する事を防止できる。特に、上記回転検出センサ３ｅから送り出される、回転速度を表す信号の様なパルス状の信号を送るハーネスと、上記温度センサ２１ｂから送り出される温度を表す信号の様なアナログ信号を送るハーネスとを一緒に束ねると、パルス状信号の電圧や電流の変動時に電磁結合（静電結合、電磁誘導、電磁波による結合）によってアナログ信号にノイズが載ってしまう。これに対して、個々のハーネスを個別にシールドする事により、上述の様にして発生するノイズを防止する事ができる。
【００３２】
又、個々のセンサ３ｅ、２１ｂの出力信号を取り出す為のハーネスと接地用のグランド線とを撚り合わせる（ツイストする）と、電磁結合によるノイズの影響を更に軽減できるのでより好ましい。又、互いに撚り合わせた状態で対となったハーネスとグランド線とから成るツイストペアを個別にシールドしたり、或は総てのツイストペアを一括してシールドする事により、ノイズの影響軽減効果を更に増大できる。特に、上記回転検出センサ３ｅの出力信号がディジタル信号である場合には、この回転検出センサ３ｅの出力信号を送る為のハーネスと、アナログ信号である温度センサ２１ｂ（更には後述の図１７に示す実施の形態の第１３例に組み込む、加速度センサ２ａ等の振動センサ）の出力信号を送る為のハーネスとを１本のケーブル４８にまとめる場合に、上記各出力信号を送る為のハーネスとグランド線とを撚り合わせる効果は大きい。
【００３３】
尚、図示の例では、環状部材１６ａに一体に形成した鍔部４５の外周縁を凹凸形状とする事により、この環状部材１６ａとエンコーダとを一体としている。これに対して、独立して円輪状としたエンコーダを環状部材とナット１７との間に挟持したり、或は、このナット１７の内端部外周面に一体に形成した外向フランジ状の鍔部の外周縁を凹凸形状として、上記ナット１７とエンコーダとを一体とする事もできる。更には、エンコーダとして、磁性金属板を曲げ形成してその一部に複数の透孔を円周方向に関して多数形成した円環状のものや、円周方向に関してＳ極とＮ極とを交互に配置した円環状の永久磁石を使用する事もできる。これらの場合に就いても、上記センサユニット３１ｇの軸方向に関する設置位置を外輪５ａ寄りにする事が可能となり、前述した従来構造の様に、ナットの軸方向外側にエンコーダがある場合と比較すると、温度センサ２１ｂの温度検出性能の向上を図る事ができる。又、上記温度センサ２１ｂにより、複列転がり軸受１ａの温度上昇をより確実に検出できる様にすべく、上記センサユニット３１ｇの一部で上記カバー９ａの外周面から突出した部分を覆う防風板を設け、このセンサユニット３１ｇが外気により冷却されるのを防止する事もできる。尚、上記ケーブル４８を上記センサユニット３１ｇから取り出す方向は、図示の様な直径方向に限らず、接線方向、その中間方向等、設置場所に応じて適宜の方向とする事ができる。この場合に、上記ケーブル４８の根元部分に、このケーブル４８の導出方向を案内する為の、Ｌ字形等の部品を設ける事もできる。
【００３４】
次に、図３は、請求項１に対応する、本発明の実施の形態の第２例を示している。本例の場合には、軸受箱１２ａを環状部材１６ａの周囲にまで延長し、センサ取付孔４６ａを、この軸受箱１２ａの端部に設けている。
この様な本例の場合、上述した第１例の場合に比べて、センサ取付座面やセンサ取付孔４６ａの加工が面倒になったり、軸受箱１２ａの軸方向寸法が大きくなって重くなったり（軸受箱の寸法が大きくなる方が、カバーの軸方向寸法が大きくなるよりも、設計上重くなりがちである）、保守・点検作業等の為に上記センサ取付孔４６ａにセンサユニット３１ｇを着脱する作業が多少面倒になったりする。但し、複列転がり軸受１ａを構成する外輪５ａから温度センサ２１ｂへの熱伝達は、上述した第１例の場合よりも良好になる。
その他の構成及び作用は、上述した第１例の場合と同様であるから、同等部分に関する説明は省略する。
【００３５】
次に、図４は、請求項１に対応する、本発明の実施の形態の第３例を示している。本例の場合には、内輪７ａ及び環状部材１６を軸方向に抑え付ける為に、車軸１１の端面に、断面クランク形で全体を円輪状に形成した抑え板４９を、複数本のボルト５０により結合固定している。そして、この抑え板４９の外周縁部分に凹部と凸部とを、円周方向に関して交互に且つ等間隔で形成して、この外周縁部分の磁気特性を円周方向に関して交互に且つ等間隔で変化させている。そして、上記抑え板４９に、回転速度検出の為の被検出リングとしての機能を持たせている。
その他の構成及び作用は、前述した第１例の場合と同様であるから、同等部分に関する説明は省略する。
【００３６】
次に、図５は、請求項１に対応する、本発明の実施の形態の第４例を示している。本例の場合には、軸受箱１２ａを抑え板４９の周囲にまで延長し、センサ取付孔４６ａを、この軸受箱１２ａの端部に設けている。
この様な本例の場合、上述した第３例の場合に比べて、センサ取付座面やセンサ取付孔４６ａの加工が面倒になったり、軸受箱１２ａの軸方向寸法が大きくなって重くなったり、保守・点検作業等の為に上記センサ取付孔４６ａにセンサユニット３１ｇを着脱する作業が多少面倒になったりする。但し、複列転がり軸受１ａを構成する外輪５ａから温度センサ２１ｂへの熱伝達は上述した第３例の場合よりも良好になる。
その他の構成及び作用は、上述した第３例の場合と同様であるから、同等部分に関する説明は省略する。
【００３７】
次に、図６は、請求項１に対応する、本発明の実施の形態の第５例を示している。本例の場合には、ホルダ４０ｅの先端部の径よりも中間部の径を大きくして、このホルダ４０ｅの外周面を段付形状としている。そして、このホルダ４０ｅの先端寄り部分に存在する段部に近接する部分に温度センサ２１ｂを設置し、更に、この温度センサ２１ｂへの熱伝達を良好とする為に、上記ホルダ４０ｅの先端部及び段部を、カバー９ａと同じ素材（例えば鉄）で覆っている。更に、本例の場合には、上記ホルダ４０ｅ内に、回転検出センサ３ｅ、温度センサ２１ｂに加えて、振動検出の為の加速度センサ２ｂを組み込んで、センサユニット３１ｈを構成している。そして、この加速度センサ２ｂの信号を取り出す為のハーネスも、上記回転検出センサ３ｅ及び温度センサ２１ｂの信号を取り出す為のハーネスと一緒に束ねて、１本のケーブル４８ａとしている。
【００３８】
尚、本例の場合も、上記１本のケーブル４８ａ内に、上記回転検出センサ３ｅの出力信号を取り出す為のハーネスと、上記温度センサ２１ｂの出力信号を取り出す為のハーネスと、上記加速度センサ２ｂの信号を取り出す為のハーネスとを納めており、これら各ハーネスは、前述した第１例の場合と同様に、グランド線と撚り合わせたり、個別にシールドしたり、グランド線と撚り合わせたツイストペアをシールドしたりしている。そして、各ハーネスを流れる信号電流同士が干渉する事を防止している。
【００３９】
本例の場合、上記回転検出センサ３ｅから送り出される、回転速度を表す信号の様なパルス状の信号を送るハーネスと、上記温度センサ２１ｂ及び加速度センサ２ｂから送り出される温度或は振動を表す信号の様なアナログ信号を送るハーネスとを一緒に束ねると、パルス状信号の電圧や電流の変動時に電磁結合によってアナログ信号にノイズが載ってしまう。これに対して、個々のハーネスをグランド線と撚り合わせたり、個別にシールドしたり、グランド線と撚り合わせたツイストペアをシールドする事により、上述の様にして発生するノイズを防止する事ができる。
【００４０】
特に、上記加速度センサ２ｂから送り出される振動を表す信号の様な、出力が小さい信号を送るハーネスの場合には、シールドしたり撚り合わせる事によるノイズ防止効果が大きいので、シールドや撚り合わせを行なう事が好ましい。シールドやグランド線との撚り合わせは、それぞれ単独で行なう事によっても効果を得られるが、両方を合わせて行なう事により、より優れたノイズ防止効果を得られる。この場合に、出力信号を送る為のハーネスとグランド線とを撚り合わせたツイストペアの周囲を一括してシールドする事が、ノイズ防止効果の面からは最も好ましい。尚、上記各センサ３ｅ、２１ｂ、２ｂの回路部分や計測器側にローパスフィルタを設ける事によっても、或る程度ノイズを除去する事は可能である。
【００４１】
又、本例の場合には、温度センサ２１ｂだけでなく、振動検出の為の振動センサとして機能する加速度センサ２ｂを設置している為、複列転がり軸受１ａ等の転がり軸受に剥離等の異常が発生した場合に、その剥離の状態を速やかに検出する事ができる。従って、上記温度センサ２１ｂのみを設置した場合に比べて、転がり軸受の異常監視に適した構造を実現できる。尚、転がり軸受の異常監視と回転速度の監視との双方を目的とする場合は、本例の様に、上記回転検出センサ３ｅと、上記温度センサ２１ｂ及び加速度センサ２ｂ等の振動センサとの３種類のセンサを組み合わせる事が最も好ましい。
【００４２】
但し、上記回転検出センサ３ｅと上記加速度センサ２ｂ等の振動センサとの組み合せ、又は、この回転検出センサ３ｅと上記温度センサ２１ｂとの組み合せによっても、転がり軸受の異常監視と回転速度の監視との双方を行なえる。これに対して、転がり軸受の異常監視のみが目的の場合は、上記温度センサ２１ｂと上記加速度センサ２ｂ等の振動センサとを組み合せ、上記回転検出センサ３ｅを省略する事もできる。この場合には、鍔部４５の外周縁部に凹凸を形成する必要はない。又、温度センサ２１ｂの出力信号を送る為のハーネスと加速度センサ２ｂ等の振動センサの出力信号を送る為のハーネスとを組み合わせる場合でも、この振動センサが検出する振動の値（振動を表す出力信号の振幅）によっては、前述した様な、個々のハーネスをグランド線と撚り合わせたり、個別にシールドしたり、グランド線と撚り合わせたツイストペアをシールドする事が好ましい。
その他の構成及び作用は、前述した第１例の場合と同様であるから、同等部分に関する説明は省略する。
【００４３】
次に、図７は、請求項１に対応する、本発明の実施の形態の第６例を示している。本例の場合には、軸受箱１２ａを環状部材１６ａの周囲にまで延長し、センサ取付孔４６ａを、この軸受箱１２ａの端部に設けている。
この様な本例の場合、上述した第５例の場合に比べて、センサ取付座面やセンサ取付孔４６ａの加工が面倒になったり、軸受箱１２ａの軸方向寸法が大きくなって重くなったり、保守・点検作業等の為に上記センサ取付孔４６ａにセンサユニット３１ｈを着脱する作業が多少面倒になったりする。但し、複列転がり軸受１ａを構成する外輪５ａから温度センサ２１ｂへの熱伝達は、上述した第５例の場合よりも良好になる。
その他の構成及び作用は、上述した第５例の場合と同様であるから、同等部分に関する説明は省略する。
【００４４】
次に、図８〜９は、請求項２に対応する、本発明の実施の形態の第７例を示している。中空円筒状に形成したハブ２２は、次述する内輪素子１８と共に、請求項に記載した内輪を構成する。このハブ２２の外端部外周面に形成したフランジ５１には、図示しない複数本のスタッドにより、車輪を構成するホイールと、制動装置を構成するディスクロータとを固定する。この様なハブ２２の中間部外周面に外側の内輪軌道６を形成し、内端部に形成した段部２３に、外周面に内側の内輪軌道６を有する上記内輪素子１８を外嵌固定している。上記ハブ２２の中心部に形成したスプライン孔２４には、自動車への組み付け状態で、図示しない等速ジョイントに付属したスプライン軸を挿入する。
【００４５】
一方、上記ハブ２２及び内輪素子１８の周囲には、内周面に複列の外輪軌道４、４を、外周面に取付部２５を、それぞれ形成した外輪５を、上記ハブ２２及び内輪素子１８と同心に配置している。このうちの取付部２５は、ナックル等の図示しない懸架装置に対し上記外輪５を支持固定する為に使用する。又、上記各外輪軌道４、４と上記各内輪軌道６、６との間に、それぞれ複数個ずつの転動体８、８を設けて、上記懸架装置に固定する外輪５の内径側に、ホイールを含む車輪を固定する上記ハブ２２及び内輪素子１８を、回転自在に支持自在としている。尚、重量の嵩む自動車用の転がり軸受ユニットの場合には、上記各転動体８、８として、図示の様な玉に代えて、円すいころを使用する場合もある。又、外側の内輪軌道６を、上記ハブ２２の外周面に直接形成するのに代えて、別体の内輪の外周面に形成する場合もある。
【００４６】
又、上記外輪５の両端部内周面と、上記ハブ２２の中間部外周面及び上記内輪素子１８の内端部外周面との間には、ぞれぞれシールリング２６、２６を装着して、上記複数の転動体８、８を設けた空間２７の両端開口部を塞いでいる。そして、この空間２７内に封入したグリースが外部に漏洩したり、外部に浮遊する異物がこの空間２７内に侵入する事を防止している。
【００４７】
又、上記ハブ２２の中間部外周面で、上記外側の内輪軌道６と前記段部２３の間部分に円筒面部２８を、上記ハブ２２と同心に形成している。そして、この円筒面部２８に被検出リング１０ｃを、締り嵌めにより外嵌固定している。この被検出リング１０ｃは、ＳＰＣＣの如き鋼板等の磁性全属板により全体を円筒状に形成したもので、軸方向中間部に、除肉部として機能する多数の透孔２９、２９を、円周方向に亙って等間隔に形成している。これら各透孔２９、２９は、それぞれが軸方向（図８の左右方向）に長いスリット状である。又、円周方向に隣り合う透孔２９、２９同士の間部分は、充実部として機能する柱部としている。この構成により、上記被検出リング１０ｃの軸方向中間部外周面の磁気特性を、円周方向に亙って交互に且つ等間隔で変化させている。
【００４８】
一方、上記外輪５の軸方向中間部で上記被検出リング１０ｃの外周面に対向する部分には取付孔３０を、上記外輪５の外周面から内周面にまで貫通する状態で形成している。そして、この取付孔３０にセンサユニット３１を、外径側開口から挿入し、このセンサユニット３１の先端面（図８の下端面）を、上記被検出リング１０ｃの外周面に近接対向させている。この様に上記取付孔３０に上記センサユニット３１を挿通自在とすべく、前記取付部２５は、この取付孔３０の外径側開口の周囲部分で不連続とし、代わりに取付座３２を、上記外輪５の外周面に形成している。上記センサユニット３１は、基端部（図８の上端部）に設けたフランジ３３を上記取付座３２にねじ止めする事により、上記外輪５に対し固定している。又、上記取付孔３０の内周面と上記センサユニット３１の外周面との間は、Ｏリング３４によりシールしている。
【００４９】
上記センサユニット３１は、図９に示す様に、合成樹脂製のホルダ（ケース）４０内に、回転検出センサ３ｃと温度センサ２１ａとを設置（包埋支持）している。このうちの回転検出センサ３ｃは、ホール素子、ＭＲ素子等の通過磁束量に応じて特性を変化させる磁気検出素子３６と、この磁気検出素子３６を通過する磁束の発生源となる、図９の上下方向に着磁した永久磁石３７と、この磁気検出素子３６の特性変化に伴う信号の波形を整える（矩形波にする）波形整形回路３８とから成る、所謂アクティブ型のセンサである。
【００５０】
そして、このうちの磁気検出素子３６を、上記被検出リング１０ｃの軸方向中間部外周面に、隙間３９を介して近接対向させている。この隙間３９の径方向に関する厚さ寸法Ｔ_３９は、０．５〜６ｍｍの範囲内に規制（Ｔ_３９＝０．５〜６ｍｍ）している。この理由は、上記回転検出センサ３ｃによる回転速度検出の性能を確保すると共に、本例のセンサユニット付複列転がり軸受の組み付け性を良好にする為である。
【００５１】
即ち、本発明者が、上記厚さ寸法Ｔ_３９を０．１〜８ｍｍの範囲で種々異ならせた試料を作成し、それぞれに就いて上記回転速度検出の性能と組み付け性とを確認する為の実験を行なった結果、次の表２に示す様な結果を得られた。尚、この表２中、符号「○」は、回転速度検出の性能或は組み付け性が良好であった事を、符号「△」は、検出性能がやや不良であった事を、符号「×」は、回転検出性能に関しては不良であった事を、組み付け性に関しては、ハブ２２及び内輪素子１８の回転に伴って上記回転検出センサ３ｃの先端部と前記被検出リング１０ｃとが接触した事を、それぞれ表している。
【００５２】
【表２】

この表２から、上記厚さ寸法Ｔ_３９を０．５〜６ｍｍの範囲に規制すれば、前記回転速度検出の性能を確保すると共に、複列転がり軸受１の組み付け性を良好にできる事が分かる。
【００５３】
又、前記温度センサ２１ａであるサーミスタは、前記ホルダ４０の先端部に包埋支持して、前記各転動体８、８を設置した空間２７内の温度を検出自在としている。この様なセンサユニット３１を構成する、前記回転検出センサ３ｃと上記温度センサ２１ａとの検出信号は、上記ホルダ４０の基端面から導出したハーネス４１を通じて取り出し、図示しない制御器に送る。
【００５４】
上述した様なセンサユニット３１を構成する上記回転検出センサ３ｃは、次の様にして、車輪の回転速度と回転数とのうちの一方又は双方を検出する。この車輪の回転に伴って前記ハブ２２に外嵌固定した被検出リング１０ｃが回転すると、上記磁気検出素子３６の近傍部分を、この被検出リング１０ｃの軸方向中間部に形成した透孔２９、２９と円周方向に隣り合う透孔２９、２９同士の間に存在する柱部とが交互に通過する。この結果、上記磁気検出素子３６内を流れる磁束量が変化し、上記回転検出センサ３ｃの出力が変化する。この出力が変化する周波数は、上記車輪の回転速度に比例する為、出力信号を上記ハーネス４１を通じて図示しない制御器に入力すれば、上記車輪の回転速度を求め、ＡＢＳやＴＣＳを適切に制御できる。又、上記出力が変化する回数で車輪の回転数を求め、更にこの回転数から走行距離を求められるので、カーナビゲーションシステムの制御に利用できる。
【００５５】
一方、上記温度センサ２１ａは、車輪支持用転がり軸受ユニットの内部である前記空間２７内の温度を検出して、やはり上記ハーネス４１を通じて図示しない制御器に送る。そして、上記車輪支持用転がり軸受ユニット部分の温度上昇やブレーキの過熱状態を知る事ができる。この車輪支持用転がり軸受ユニット部分の温度上昇は、この車輪支持用転がり軸受ユニット自体の寿命を知る上での重要なデータとなるだけでなく、ブレーキ部分の過熱状態を知り、ベーパロック等の危険な状態が出現する以前に、運転者に警告を発する事に利用できる。
【００５６】
尚、ブレーキ部分の過熱状態は、前記ディスクロータから上記ハブ２２に伝わる為、上記温度センサ２１ａを前記センサユニット３１の先端面に設置して、このハブ２２に近接対向させる事が好ましい。これに対して、上記車輪支持用転がり軸受ユニット部分の温度上昇は、前記外輪５の温度から知る事もできる。そして、この外輪５の温度を測定する為に、上記温度センサ２１ａを、前記ホルダ４０の中間部で前記取付孔３０の内周面に対向する部分に設置する事もできる。何れにしても、上記温度センサ２１ａを被測定部に近接若しくは当接させて配置する事により、この被測定部の温度を正確に測定でき、車輪支持用転がり軸受ユニットの異常やブレーキの過熱状態を早期に察知し、警報を発する事ができる。
【００５７】
しかも、上記温度センサ２１ａは、前記回転検出センサ３ｃを保持したものと同一のホルダ４０内に包埋支持している為、上記温度センサ２１ａの重量並びに組み付けスペースが嵩んだり、組み付け工数が増大して、自動車の製造コストを徒に増大させる事がない。又、上記各センサ３ｃ、２１ａの検出信号を制御器に送る導線にしても、同一の被覆内に納めた１本のハーネス４１にまとめる事ができる為、このハーネス４１の重量の軽減や配線作業の簡略化を図れる。
【００５８】
次に、図１０は、請求項２に対応する、本発明の実施の形態の第８例を示している。本例に使用するセンサユニット３１ａは、合成樹脂製のホルダ４０ａ内に、それぞれが回転検出センサ３ｃを構成する為の、磁気検出素子３６、永久磁石３７、波形整形回路３８の他、加速度センサ２ａを包埋支持している。この加速度センサ２ａは、複列転がり軸受部分の振動を測定する為の振動センサとして機能するもので、例えば圧電素子を用いた小型の加速度センサと信号処理回路とを、基板４２に実装した状態で、上記ホルダ４０ａ内にモールドして成る。この様な加速度センサ２ａは、上記センサユニット３１ａ全体を小型化する為に、図１０に示す様に、上記ホルダ４０ａの軸方向（図１０の上下方向）に関して、上記磁気検出素子３６及び上記永久磁石３７と直列に、これら両部材よりも基端側（図１０の上側）に設置する事が好ましい。
【００５９】
上述の様なセンサユニット３１ａを、車輪支持用の複列転がり軸受を構成する外輪５（図８参照）に対し固定して、更に上記各センサ３ｃ、２ａの出力信号を取り出す構造、及び、このうちの回転検出センサ３ｃにより車輪の回転速度を検出する際の作用は、前述した第７例の場合と同様である。
特に、本例の場合には、上記加速度センサ２ａを合成樹脂製のホルダ４０ａ内に包埋支持する事により、センサユニット３１ａと一体とし、このセンサユニット３１ａを上記外輪５にがたつきなく固定しているので、この外輪５の振動を正確に測定できる。この外輪５には、車輪からハブ２２に伝わる振動が転動体８、８（図８参照）を介して伝達される為、上記加速度センサ２ａから出力される信号を図示しない制御器に入力すれば、上記車輪が接地している路面の凹凸、タイヤの空気圧、加減速状況等を知る事ができる。そして、懸架装置に組み込んだダンパーの減衰量を自動的に調節したり、エンジンの出力を調整したりできる。又、車輪支持用転がり軸受ユニットが寿命に達した事に伴って発生する異常振動を検出し、運転者に警告を発する事もできる。
【００６０】
尚、上記加速度センサ２ａが検出する振動の方向は、上記車輪支持用転がり軸受ユニットを懸架装置に支持した状態（設置状態）での上記加速度センサ２ａの方向を規制する事により、自由に調節可能である。例えば、この加速度センサ２ａを一般的な圧電素子により構成した場合に就いて考えると、この加速度センサ２ａで検出できる振動の方向は、図１１（Ａ）に示したａ軸、ｂ軸、ｃ軸の何れかの方向になる。これら各軸に対し直角方向の振動は殆ど検出されず、これら各軸に対し傾斜方向に加わる振動は、これら各軸と平行な成分が検出される。
【００６１】
そこで、図１１の（Ｂ）（Ｃ）を設置状態とし、これら図１１の（Ｂ）（Ｃ）に関して、Ｘ方向を車両の幅方向、Ｙ方向を車両の前後方向、Ｚ方向を車両の上下方向とした場合に就いて考える。尚、図１１の（Ｂ）（Ｃ）で加速度センサ２ａ内に示した矢印は、この加速度センサ２ａが検出する振動の方向を表している。先ず、図１１の（Ｂ）に示す様に、この加速度センサ２ａの検出方向と上記Ｚ方向とを一致させた場合には、車両の上下方向の振動を効果的に検出でき、進行方向及び幅方向の振動は検出しない。又、上下方向に対し傾斜した方向に加わる振動は、そのうちの上下方向の成分を検出する。次に、図１１の（Ｃ）に示す様に、加速度センサ２ａの検出方向と上記Ｙ方向とを一致させた場合には、車両の前後方向の振動を効果的に検出でき、上下方向及び幅方向の振動は検出しない。又、前後方向に対し傾斜した方向に加わる振動は、そのうちの前後方向の成分を検出する。尚、図１１で４４は、振動センサの検出信号を処理する為の信号処理回路である。
【００６２】
次に、図１２は、請求項２に対応する、本発明の実施の形態の第９例を示している。本例に使用するセンサユニット３１ｂは、合成樹脂製のホルダ４０ｂ内に、回転検出センサ３ｃの他、温度センサ２１ａ及び加速度センサ２ａを包埋支持している。このうちの温度センサ２１ａの作用は前述の第７例の場合と、加速度センサ２ａの作用は前述した第８例の場合と、それぞれ同様である為、同等部分には同一符号を付して重複する説明を省略する。
【００６３】
次に、図１３は、請求項１、２に対応する、本発明の実施の形態の第１０例を示している。本例に使用するセンサユニット３１ｃは、回転検出センサ３ｃと、温度センサ２１ａと、加速度センサ２ａとを包埋した合成樹脂製のホルダ４０ｃを、アルミニウム、銅、非磁性ステンレス等の、非磁性金属製のケース４３内に保持している。この様なケース４３を設ける事により、センサユニット３１ｃの強度向上を図ると共に、上記回転検出センサ３ｃが、外部磁束による影響を受けにくくしている。更に、上記温度センサ２１ａをケース４３に接触させた状態で設置する事により、この温度センサ２１ａによる温度検出性能の向上を図っている。尚、この様なケース４３を設ける構造は、図９に示した第７例、或は図１２に示した第９例の構造と組み合わせる事もできる。
【００６４】
次に、図１４〜１５は、請求項２に対応する、本発明の実施の形態の第１１例を示している。本例の場合には、ハブ２２の回転速度を検出する為にこのハブ２２に外嵌固定した被検出リング１０ｄとして、永久磁石製のものを使用している。この被検出リング１０ｄは、円筒状の芯金の外周面に、フェライト粉末や希土類磁石粉末等を混入したゴム磁石製のエンコーダ本体を、全周に亙って添着して成る。このうちのエンコーダ本体は、プラスチック磁石やボンド磁石でも良い。又、上記芯金は、各種金属或は合成樹脂等でも良いが、炭素鋼板等の磁性金属板製であれば、上記エンコーダ本体の外周面から出る磁束の強度を大きくできて、このエンコーダ本体の外周面とホルダ４０内に設置された回転検出センサ３ｄの検出部との間の隙間３９を広くしても回転検出の信頼性確保を図れるので好ましい。更に、上記被検出リング１０ｄは、芯金を設けずに、上記エンコーダ本体を上記ハブ２２の外径面に直接、樹脂モールドや接着で固着する事により構成しても良い。
【００６５】
何れにしても、上記エンコーダ本体は直径方向に着磁されており、着磁方向は円周方向に関して交互に且つ等間隔に変化させている。従って上記被検出リング１０ｄの外周面にはＳ極とＮ極とが、円周方向に関して交互に且つ等間隔で配置されている。尚、上記エンコーダ本体の着磁パターンは、交互且つ等間隔とする事が一般的ではあるが、必ずしもそうする必要はない。例えば、特開２０００−３４６６７３号公報に記載されている様に、Ｓ極とＮ極と無着磁領域とを交互に繰り返す様な着磁パターンを採用すれば、回転速度だけでなく回転方向の検出も可能になる。要は、必要とする機能に合わせて所望の着磁パターンを採用すれば良い。
【００６６】
何れにしても、上記被検出リング１０ｄとして永久磁石を使用する事に合わせて、外輪５の取付孔３０に装着したセンサユニット３１ｃには、前述の図９に示した様な永久磁石３７は設けてはいない。即ち、このセンサユニット３１ｃには、回転検出センサ３ｄとなる磁気検出素子３６及び波形整形回路３８と、温度センサ２１ａとを設置（包埋支持）している。その他の部分の構成及び作用は、前述の図８〜９に示した第７例と同様であるから、同等部分には同一符号を付して、重複する説明を省略する。
【００６７】
次に、図１６は、請求項２に対応する、本発明の実施の形態の第１２例を示している。本例に使用するセンサユニット３１ｄは、合成樹脂製のホルダ４０ａ内に、回転検出センサ３ｄを構成する為の、磁気検出素子３６及び波形整形回路３８に加えて、加速度センサ２ａを包埋支持している。被検出リング１０ｄ（図１４参照）として永久磁石を使用する事に合わせて、上記回転検出センサ３ｄに永久磁石を組み込んでいない点を除き、前述の図１０に示した第８例と同様であるから、同等部分には同一符号を付して、重複する説明を省略する。
【００６８】
次に、図１７は、請求項２に対応する、本発明の実施の形態の第１３例を示している。本例に使用するセンサユニット３１ｅは、合成樹脂製のホルダ４０ｂ内に、回転検出センサ３ｄの他、温度センサ２１ａ及び加速度センサ２ａを包埋支持している。被検出リング１０ｄ（図１４参照）として永久磁石を使用する事に合わせて、上記回転検出センサ３ｄに永久磁石を組み込んでいない点を除き、前述の図１２に示した第９例と同様であるから、同等部分には同一符号を付して、重複する説明を省略する。
【００６９】
次に、図１８は、請求項１、２に対応する、本発明の実施の形態の第１４例を示している。本例に使用するセンサユニット３１ｆは、回転検出センサ３ｄと加速度センサ２ａとを包埋した合成樹脂製のホルダ４０ｃを、アルミニウム、銅、非磁性ステンレス等の、非磁性金属製のケース４３内に保持している。被検出リング１０ｄ（図１４参照）として永久磁石を使用する事に合わせて、上記回転検出センサ３ｄに永久磁石を組み込んでいない点を除き、前述の図１３に示した第１０例と同様であるから、同等部分には同一符号を付して、重複する説明を省略する。
【００７０】
【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ので、回転速度や振動、温度等の、互いに異なる２種類以上の状態値を正確に測定できるセンサユニット付複列転がり軸受を実現できる。
【図面の簡単な説明】
【図１】本発明の実施の形態の第１例を示す、図２のＡ−Ａ断面図。
【図２】図１の左側から見た図。
【図３】本発明の実施の形態の第２例を示す要部断面図。
【図４】同第３例を示す要部断面図。
【図５】同第４例を示す要部断面図。
【図６】同第５例を示す要部断面図。
【図７】同第６例を示す要部断面図。
【図８】同第第７例を示す断面図。
【図９】同第７例に組み込むセンサユニットの断面図。
【図１０】同第８例に組み込むセンサユニットの断面図。
【図１１】１方向の振動のみを検出できる振動センサを使用する場合の設置状態を説明する為の斜視図。
【図１２】本発明の実施の形態の第９例に組み込むセンサユニットの断面図。
【図１３】同第１０例に組み込むセンサユニットの断面図。
【図１４】同第１１例を示す断面図。
【図１５】同第１１例に組み込むセンサユニットの断面図。
【図１６】同第１２例に組み込むセンサユニットの断面図。
【図１７】同第１３例に組み込むセンサユニットの断面図。
【図１８】同第１４例に組み込むセンサユニットの断面図。
【図１９】従来構造の第１例を示す断面図。
【図２０】図１９のＢ−Ｂ断面図。
【図２１】従来構造の第２例を示す、図２２のＣ−Ｏ−Ｄ断面図。
【図２２】図２１の左側から見た図。
【図２３】従来構造の第３例を示す断面図。
【符号の説明】
１、１ａ、１ｂ　複列転がり軸受
２、２ａ、２ｂ　加速度センサ
３、３ａ、３ｂ、３ｃ、３ｄ、３ｅ　回転検出センサ
４、４ａ　外輪軌道
５、５ａ　外輪
６、６ａ　内輪軌道
７、７ａ　内輪
８、８ａ　転動体
９、９ａ　カバー
１０、１０ａ、１０ｂ、１０ｃ、１０ｄ　被検出リング
１１　　車軸
１２　　軸受箱
１３　　保持器
１４　　内輪素子
１５　　間座
１６、１６ａ　環状部材
１７　　ナット
１８　　内輪素子
１９、１９ａ　円筒部
２０　　センサ取付用凹孔
２１、２１ａ、２１ｂ　温度センサ
２２　　ハブ
２３　　段部
２４　　スプライン孔
２５　　取付部
２６　　シールリング
２７　　空間
２８　　円筒面部
２９　　透孔
３０　　取付孔
３１、３１ａ、３１ｂ、３１ｃ、３１ｄ、３１ｅ、３１ｆ、３１ｇ、３１ｈ　センサユニット
３２　　取付座
３３　　フランジ
３４、３４ａ　０リング
３５　　取付フランジ
３６　　磁気検出素子
３７　　永久磁石
３８　　波形整形回路
３９、３９ａ　隙間
４０、４０ａ、４０ｂ、４０ｃ、４０ｄ、４０ｅ　ホルダ
４１　　ハーネス
４２　　基板
４３　　ケース
４４　　信号処理回路
４５　　鍔部
４６、４６ａ　センサ取付孔
４７　　ボルト
４８、４８ａ　ケーブル
４９　　抑え板
５０　　ボルト
５１　　フランジ[0001]
TECHNICAL FIELD OF THE INVENTION
A double-row rolling bearing with a sensor unit according to the present invention can be used, for example, to rotate a wheel of a railway vehicle or an automobile, or a rotating shaft of a rolling mill for metal working with respect to a housing or a suspension device which does not rotate during use. It is freely supported and is used to detect the state of the double row rolling bearing. Such a double-row rolling bearing with a sensor unit detects, for example, the rotational speed of the wheel or the rotating shaft and the state (temperature, vibration, etc.) of the double-row rolling bearing, and detects the double-row rolling bearing. This is effective for determining the presence or absence of an abnormality in a part.
[0002]
[Prior art]
In order to rotatably support a rotating member such as a wheel with respect to a stationary member such as a suspension device, a double-row rolling bearing is widely used. Providing a rotational speed sensor or an acceleration sensor on the double row rolling bearing to detect the rotational speed or vibration of a rotating member such as the wheel has been conventionally proposed and partially implemented. For example, Japanese Utility Model Laid-Open No. 5-12744 (Utility Model Registration No. 2543369) describes a structure in which an acceleration sensor 2 and a rotation detection sensor 3 are incorporated in a double-row rolling bearing 1 as shown in FIGS. Have been. A similar structure is also described in JP-T-2001-500977 (US Pat. No. 6,161,962).
[0003]
In the case of the conventional structure described in Japanese Utility Model Application Laid-Open No. 5-12744, a double-row inner raceway 6 is provided on the inner peripheral surface of the outer race 5 provided with the double-row outer raceways 4 on the inner peripheral surface. , 6 are rotatably supported by a plurality of rolling elements 8, 8. An annular detection ring 10 is externally fitted and fixed to the end of the inner ring 7. Then, of the acceleration sensor 2 and the rotation detection sensor 3, the detection unit of the rotation detection sensor 3 held in the cover 9 attached to the end opening of the outer ring 5 is opposed to the detection ring 10. ing.
[0004]
Among the acceleration sensor 2 and the rotation detection sensor 3, the detection signal of the acceleration sensor 2 is used to determine the vibration generated in the double row rolling bearing 1 and to know the end of the life of the double row rolling bearing 1. I do. Further, the detection signal of the rotation detection sensor 3 is used to determine the rotation speed of the wheels supported by the double row rolling bearing 1 and to control an antilock brake system (ABS) or a traction control system (TCS). .
[0005]
The structure shown in FIGS. 19 and 20 above relates to a double-row rolling bearing for an automobile. However, in the case of a double-row rolling bearing for a railway vehicle, the running speed is determined or other conditions such as temperature are determined. It is being made detectable. Of these, the running speed is necessary for performing sliding control for preventing uneven wear of the wheels, and the temperature is necessary for preventing the double-row rolling bearing from seizing. For this reason, a rotation supporting device with a sensor for railway vehicles as shown in FIGS. 21 to 22 is conventionally known.
[0006]
The axle 11 that rotates during use while supporting and fixing wheels (not shown) is rotatably supported by a double-row rolling bearing 1a on the inner diameter side of a bearing box 12 that does not rotate during use. The double-row rolling bearing 1a is a double-row tapered roller bearing, and includes an outer ring 5a and an inner ring 7a which are arranged concentrically with each other, and a plurality of rolling elements 8a, 8a which are tapered rollers. Each of these rolling elements 8a, 8a is provided in plural numbers between a double-row outer raceway 4a formed on the inner peripheral surface of the outer race 5a and a double-row inner raceway 6a formed on the outer peripheral surface of the inner race 7a. It is provided so as to roll freely while being held by the holder 13.
[0007]
Of the double row rolling bearing 1a as described above, the outer ring 5a is internally fitted and held in the bearing box 12. On the other hand, the inner ring 7a is formed by sandwiching a spacer 15 between a pair of inner ring elements 14, and is fitted around a portion of the axle 11 near one end (the left end in FIG. 21). An annular member 16 called an oil drain is externally fitted to a portion of the end of the axle 11 protruding from the axially outer inner ring element 14. Further, the inner end surface of the inner inner ring element abuts on a step surface formed in the intermediate portion of the axle 11 via another annular member. Therefore, the pair of inner ring elements 14 is not displaced closer to the center of the axle 11 (rightward in FIG. 21) than in the state of FIG. The annular member 16 is pressed toward the outer end surface of the outer inner ring element 14 by a nut 17 screwed to the outer end of the axle 11.
[0008]
On one end surface of the axle 11, a detection ring 10a having an L-shaped cross section and formed in a ring shape as a whole is fixed with a magnetic metal material such as steel. Concave portions and convex portions are formed alternately and at regular intervals in the circumferential direction on the outer peripheral surface (outer peripheral edge) of the detected ring 10a, and the outer peripheral surface portion is formed in a gear shape. The characteristics are changed alternately and at regular intervals in the circumferential direction.
[0009]
One end opening of the bearing box 12 is closed by a cover 9a formed in a cylindrical shape with a bottom by a synthetic resin or a metal material. The rotation detecting sensor 3a is inserted into a sensor mounting hole 46 formed in a part of the cylindrical portion 19 constituting the cover 9a and diametrically opposed to the outer peripheral edge of the detected ring 10a. A detection unit provided on the tip end surface (lower end surface in FIG. 21) of the rotation detection sensor 3a faces the outer peripheral edge of the detected ring 10a via a gap.
On the other hand, a sensor mounting concave hole 20 is formed in a portion located in the middle of the bearing housing 12 around the outer ring 5a. The temperature sensor 21 is mounted in the sensor mounting recess 20.
[0010]
In the case of the rotation supporting device with a sensor configured as described above, when the detected ring 10a rotates together with the axle 11 that supports and fixes the wheels during driving, the concave portion and the convex portion forming the detected portion of the detected ring 10a Pass alternately in the vicinity of a detection unit provided on the tip end surface of the rotation detection sensor 3a. As a result, the density of the magnetic flux flowing in the rotation detection sensor 3a changes, and the output of the rotation detection sensor 3a changes. The frequency at which the output of the rotation detection sensor 3a changes in this way is proportional to the rotation speed of the wheel. Therefore, if the output of the rotation detection sensor 3a is sent to a controller (not shown), the rotation speed of the wheels can be detected, and the sliding control of the railway vehicle can be appropriately performed.
[0011]
When the rotational resistance of the double-row rolling bearing 1a abnormally rises for some reason, such as skew of the rolling elements 8a, 8a, and the temperature of the double-row rolling bearing 1a rises, the temperature sensor 21 This temperature is detected. The temperature signal detected by the temperature sensor 21 in this manner is also sent to a controller (not shown), and the controller issues an alarm such as turning on a warning light installed in the driver's seat. When such an alarm is issued, the driver takes measures such as an emergency stop.
[0012]
[Problems to be solved by the invention]
In the case of the first example of the conventional structure shown in FIGS. 19 and 20, the acceleration sensor 2 and the rotation detection sensor 3 are supported on the outer ring 5 via the cover 9 and the ring-shaped detection ring 10 is used. It may not always be possible to accurately measure state values such as vibration and rotation speed.
[0013]
In addition, in the case of the second example of the conventional structure shown in FIGS. 21 to 22, since the rotation detection sensor 3a and the temperature sensor 21 are separate bodies, the mounting work of these sensors 3a and 21 and the respective sensors 3a , 21 is troublesome to arrange the harness for extracting the detection signals. It is also conceivable to combine the structure of the first example with the structure of the second example, that is, combine the rotation detection sensor 3a and the temperature sensor 21 to form a sensor unit and assemble the cover 9a. However, in this case, consideration must be given to enable the temperature detection by the temperature sensor 21 to be performed effectively.
[0014]
In Japanese Patent No. 2838701, as shown in FIG. 23, the rotation detection sensor 3b is directly fixed to the outer ring 5 and the detection surface (tip surface) of the rotation detection sensor 3b is Describes a structure in which the detection ring 10b is externally fitted and directly opposed to a detection target portion (outer peripheral edge) of the detection target ring 10b. However, the third example of the conventional structure described in Japanese Patent No. 2838701 considers only the detection of the rotation speed of the inner ring 7, and the vibration generated in the double-row rolling bearing 1b portion, No consideration is given to measuring the temperature of the double-row rolling bearing 1b.
In view of such circumstances, the present invention has been made to realize a double row rolling bearing with a sensor unit capable of accurately measuring two or more different state values such as rotation speed, vibration, and temperature. .
[0015]
[Means for Solving the Problems]
Among the double row rolling bearings with a sensor unit of the present invention, the double row rolling bearing with a sensor unit according to claim 1 is an outer ring having a double row outer raceway on an inner peripheral surface, and a double row inner raceway on an outer peripheral surface. An inner ring, a plurality of rolling elements provided between the respective outer ring raceways and the respective inner ring raceways so as to be freely rotatable, and one or other members directly on one of the outer race and the inner race. And a sensor unit fixed via the sensor ring. This sensor unit includes a plurality of sensors that detect different states including rotation speed and temperature, and a material having good heat conductivity such as copper or its alloy, aluminum or its alloy, iron or its alloy, or the like. And held in a case made of Then, the sensor unit was supported directly or via another member on the other orbital ring of the outer ring and the inner ring in a space shielded from the outside in a state facing the ring to be detected. It is provided in a state.
[0016]
A double row rolling bearing with a sensor unit according to claim 2 is an outer ring having a double row outer raceway on an inner peripheral surface, an inner race having a double row inner raceway on an outer peripheral surface, and each outer raceway. A rolling element is provided between the inner raceway and the inner raceway so as to freely roll, a detected ring directly fixed to the inner race, and a sensor unit. The sensor unit includes a plurality of sensors for detecting different states, and is supported by the outer ring in a state facing the detected ring.
[0017]
The double-row rolling bearing with a sensor unit according to the first or second aspect of the present invention is preferably configured such that the detected ring has a gear-shaped unevenness formed on an outer peripheral edge (outer peripheral surface), and the sensor includes a ring. The detection unit of the rotation detection sensor constituting the unit is made to face the outer peripheral edge of the detected ring. In this case, the thickness dimension in the radial direction of the gap between the detection portion of the rotation detection sensor and the outer peripheral edge (the tip of the convex portion) of the detected ring is determined by the height of the irregularities (the bottom of the concave portion and the convex portion). (A distance in the radial direction from the top of the part) to a range of not less than 1/4 and not more than 3 times.
In addition, as a rotation detection sensor constituting the sensor unit, preferably, a so-called active type incorporating a magnetic detection element such as a Hall element or a magnetoresistive element that changes characteristics according to a change in the density or direction of a magnetic flux. Use a sensor. In this case, the thickness dimension in the radial direction of the gap between the detection portion of the rotation detection sensor and the outer peripheral edge of the detected ring is restricted to a range of 0.5 to 6 mm.
More preferably, the plurality of sensors constituting the sensor unit include at least one of a temperature sensor and a vibration sensor (acceleration sensor) in addition to the rotation detection sensor.
[0018]
[Action]
The double row rolling bearing with a sensor unit of the present invention configured as described above can accurately measure state values such as rotation speed, vibration, and temperature.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
First, FIGS. 1 and 2 show a case where the present invention is applied to a double-row rolling bearing for a railway vehicle, as a first example of an embodiment of the present invention corresponding to claim 1. The feature of this example is that a rotation detection sensor 3e for detecting the rotation speed of the axle 11 and a temperature sensor 21b for detecting the temperature of a double row rolling bearing that rotatably supports the axle 11 are provided. By holding the holder in one holder 40d, the problem of the conventional structure described above is solved. Since the structure and operation of the other parts are the same as those of the second example of the conventional structure shown in FIGS. 21 to 22, the same reference numerals are given to the same parts, and the description of the overlapping parts will be omitted. Or, for simplicity, the following mainly describes the features of the present example.
[0020]
In the case of the present example, an outward flange-shaped flange portion 45 is formed over the entire circumference on the outer peripheral surface of an outer end portion of an annular member 16a called an oil drain provided inside the nut 17 in the axial direction. ing. A concave portion and a convex portion are formed alternately and at equal intervals in the circumferential direction on the outer peripheral edge of the flange portion 45, and the magnetic characteristics of the outer peripheral portion are alternately and equally spaced at the circumferential direction. Is changing. The flange 45 has a function as a detected ring for detecting the rotation speed.
[0021]
In the case of such a structure of the present example, as compared with the case where the detected ring 10a is provided on the outside in the axial direction of the nut 17 as in the conventional structure shown in FIG. The installation position in the direction can be closer to the outer ring 5a, and the temperature detection performance by the temperature sensor 21b described later can be improved. Further, a concave portion and a convex portion are formed on the outer peripheral edge of the flange portion 45 formed on the outer peripheral surface of the annular member 16a, and the annular member 16a has a function as an encoder. In comparison with the above, effects such as reduction in the number of parts, reduction in axial dimension, weight reduction, and cost reduction can be obtained.
[0022]
Further, a sensor mounting hole 46a is provided at a portion near the base end (near the right end in FIG. 1) of the cylindrical portion 19a constituting the cover 9a made of metal such as steel or aluminum, which closes the end opening of the bearing housing 12. The inner and outer peripheral surfaces of the cylindrical portion 19a are formed to communicate with each other. Then, the sensor unit 31g is inserted into the sensor mounting hole 46a inward from the radial outside of the cylindrical portion 19a.
[0023]
The sensor unit 31g is configured to hold the rotation detection sensor 3e and the temperature sensor 21b in the single holder 40d. Among them, the rotation detecting sensor 3e which changes the output in response to a change in the density or direction of the magnetic flux, such as a magnetoresistive element, a Hall element, a combination of a permanent magnet and a magnetic coil, is used as in the conventional case. I do. Such a rotation detection sensor 3e is embedded in the distal end of the holder 40d, and its detection surface is closely opposed to the outer peripheral edge of the flange 45.
[0024]
When a so-called active type using a magnetoresistive element, a Hall element, or the like is used as the rotation detection sensor 3e, the rotation detection sensor 3e is provided on the distal end surface (the lower end surface in FIG. 1) of the sensor unit 31g. The thickness T of the gap 39a existing between the detection surface of the rotation detection sensor 3e and the outer peripheral edge of the flange 45. _39a Is preferably regulated to a range of 0.5 to 6 mm, as described in a sixth example of an embodiment of the present invention described later. On the other hand, when a so-called passive type in which a permanent magnet and a magnetic coil are combined is used as the rotation detection sensor 3e, the thickness T _39a Is restricted within a range of not less than ４ and not more than 3 times the height of the unevenness (the distance in the radial direction between the bottom of the concave portion and the top of the convex portion) formed on the outer peripheral edge of the flange 45. The reason for this is to ensure the performance of the rotation speed detection by the rotation detection sensor 3e and to improve the assemblability of the double row rolling bearing with the sensor unit of the present embodiment.
[0025]
That is, the present inventor incorporates a passive rotation detection sensor, and has the thickness T _39a Various samples were prepared in the range of 1/6 to 5 times the height of the irregularities, and an experiment was performed to confirm the rotational speed detection performance and assemblability of each sample. The results as shown in the following Table 1 were obtained. In Table 1, the symbol “○” indicates that the rotation speed detection performance or the assemblability was good, and the symbol “△” indicates that the detection performance was slightly poor, and the symbol “×” Indicates that the rotation detection performance was poor, and the assemblability was that the tip of the rotation detection sensor 3e and the outer peripheral edge of the flange 45 contacted with the rotation of the axle 11. Each is represented.
[0026]
[Table 1]

From Table 1, the thickness T _39a Is restricted to a range of 1/4 to 3 times the height of the unevenness, it can be understood that the performance of detecting the rotational speed can be secured and the assemblability of the double-row rolling bearing 1a can be improved.
[0027]
On the other hand, the temperature sensor 21b is supported on a part of the holder 40d near the outer peripheral surface. The position where the temperature sensor 21b is supported is as close as possible to the cover 9a, and is a portion that is easily affected by heat transmitted from the outer ring 5a to the cover 9a. In order to improve the temperature detection performance of the temperature sensor 21b, the heat conductivity of the holder 40d must be good, and the temperature of the holder 40d should reach the ambient temperature in a short time. It is necessary that the heat capacity of the holder 40d is small.
[0028]
Therefore, a material having a high thermal conductivity and a small heat capacity per unit volume (= density × specific heat) is suitable as the material of the holder 40d. Specifically, it is preferable to use aluminum, magnesium, copper, zinc, or the like, or an alloy thereof, having the above-described properties, as long as there is no problem in strength and cost as the material of the holder 40d. In addition, in order to facilitate heat transfer from the outer ring 5a to the temperature sensor 21b, it is desirable to use these materials for the bearing housing 12 and the cover 9a as long as there is no problem in strength and cost. . When there is a problem in strength, the holder 40d may be made of stainless steel. However, the holder 40d is made of non-magnetic material even when it is made of stainless steel. The reason is that if the holder 40d is made of a magnetic material, the magnetism of the holder 40d hinders measurement of the rotation speed by the rotation detection sensor 3e, and it becomes difficult to measure the rotation speed accurately. is there. Therefore, the material of the holder 40d is preferably a non-magnetic material.
[0029]
With the sensor unit 31g as described above, the mounting flange 35 provided on the outer peripheral surface is inserted into the sensor mounting hole 46a from the radial outside to the inner side of the cylindrical portion 19a, and the outer peripheral surface of the cylindrical portion 19a. Are fixed by bolts 47 and 47. In this state, the detection unit of the rotation detection sensor 3e present on the distal end surface of the sensor unit 31g closely faces the detection target provided on the outer peripheral edge of the flange 45 via the gap 39a. Further, the temperature sensor 21b is closely opposed to the cylindrical portion 19a of the cover 9a via a part of the holder 40d. A harness for extracting the output signal of the rotation detection sensor 3e and a harness for extracting the output of the temperature sensor 21b are bundled together to form a single cable 48, which is connected to a controller (not shown). Also, an O-ring 34a is mounted between a part of the outer peripheral surface of the holder 40d and the inner peripheral surface of the sensor mounting hole 46a, and foreign matter such as muddy water enters from outside through a part between the two peripheral surfaces. Has been prevented. Therefore, the sensor unit 31g is supported by the cover 9a in a space shielded from the outside.
[0030]
As described above, in the case of the double row rolling bearing with the sensor unit of the present embodiment, since the rotation detection sensor 3e and the temperature sensor 21b are held in a single holder 40d, the two sensors 3e and 21b are used. Installation space can be reduced. Moreover, the mounting work of these two sensors 3e and 21b becomes easy. Also, since the harnesses for extracting the output signals of the two sensors 3e and 21b are bundled together to form a single cable 48, it is easy to handle the harness for extracting the signals of the two sensors 3e and 21b. Further, in the case of this example, since the sensor unit 31g is supported by the cover 9a which is detachably provided in the opening of the bearing housing 12, the sensor unit 31g is attached and detached for maintenance and inspection work. Work can be performed easily.
[0031]
The one cable 48 contains a harness for extracting the output signal of the rotation detection sensor 3e and a harness for extracting the output signal of the temperature sensor 21b. Shielded individually. Even when a plurality of harnesses are bundled into one cable 48 in this manner, the signal currents flowing through the respective harnesses can be prevented from interfering with each other by individually shielding the respective harnesses. In particular, a harness that sends out a pulse-like signal such as a signal indicating a rotation speed sent from the rotation detection sensor 3e and a harness that sends an analog signal such as a signal indicating the temperature sent out from the temperature sensor 21b are combined. If the voltage and the current of the pulse-like signal fluctuate, noise will appear on the analog signal due to electromagnetic coupling (electrostatic coupling, electromagnetic induction, coupling by electromagnetic waves). On the other hand, by individually shielding each harness, it is possible to prevent noise generated as described above.
[0032]
It is more preferable to twist (twist) a harness for extracting output signals of the individual sensors 3e and 21b and a ground wire for grounding, because the influence of noise due to electromagnetic coupling can be further reduced. In addition, the effect of reducing the effect of noise is further increased by individually shielding the twisted pair consisting of the harness and the ground wire that are paired in a twisted state, or by shielding all twisted pairs collectively. it can. In particular, when the output signal of the rotation detection sensor 3e is a digital signal, a harness for transmitting the output signal of the rotation detection sensor 3e and a temperature sensor 21b which is an analog signal (see FIG. 17 described later) When the harness for transmitting the output signal of the vibration sensor such as the acceleration sensor 2a incorporated in the thirteenth example of the embodiment is combined into one cable 48, the harness and the ground line for transmitting the output signal are combined. The effect of twisting is great.
[0033]
In the illustrated example, the annular member 16a and the encoder are integrated with each other by forming the outer peripheral edge of the flange portion 45 integrally formed with the annular member 16a into an uneven shape. On the other hand, an independently annular encoder is sandwiched between the annular member and the nut 17, or an outward flange-shaped flange formed integrally with the outer peripheral surface of the inner end of the nut 17. The nut 17 and the encoder can be integrated with each other by forming the outer peripheral edge of the nut into an uneven shape. Further, as an encoder, a magnetic metal plate is formed by bending and a plurality of through-holes are formed in a part of the magnetic metal plate in an annular shape, or an S pole and an N pole are alternately arranged in the circumferential direction. An annular permanent magnet can also be used. Even in these cases, it is possible to position the sensor unit 31g in the axial direction closer to the outer ring 5a, as compared with the case where the encoder is located outside the nut in the axial direction as in the conventional structure described above. Thus, the temperature detection performance of the temperature sensor 21b can be improved. In order to more reliably detect the temperature rise of the double row rolling bearing 1a by the temperature sensor 21b, a windshield plate that covers a portion of the sensor unit 31g that protrudes from the outer peripheral surface of the cover 9a is provided. It is also possible to prevent the sensor unit 31g from being cooled by outside air. The direction in which the cable 48 is taken out from the sensor unit 31g is not limited to the diametrical direction as shown in the figure, but may be an appropriate direction such as a tangential direction or an intermediate direction depending on the installation location. In this case, an L-shaped part or the like for guiding the cable 48 in the lead-out direction can be provided at the root of the cable 48.
[0034]
Next, FIG. 3 shows a second example of the embodiment of the present invention corresponding to claim 1. In the case of this example, the bearing box 12a is extended to the periphery of the annular member 16a, and the sensor mounting hole 46a is provided at an end of the bearing box 12a.
In the case of such a present example, as compared with the case of the first example described above, processing of the sensor mounting seat surface and the sensor mounting hole 46a becomes troublesome, and the axial size of the bearing box 12a becomes large and heavy. (A larger bearing housing tends to be heavier in design than a larger cover axial size.) The sensor unit 31g is attached to and detached from the sensor mounting hole 46a for maintenance and inspection work. Work is a little cumbersome. However, heat transfer from the outer ring 5a constituting the double row rolling bearing 1a to the temperature sensor 21b is better than in the case of the first example described above.
Other configurations and operations are the same as those in the above-described first example, and a description of equivalent parts will be omitted.
[0035]
Next, FIG. 4 shows a third example of the embodiment of the present invention corresponding to claim 1. In the case of this example, in order to hold down the inner race 7a and the annular member 16 in the axial direction, a holding plate 49 formed in a ring shape with a crank-shaped cross section is provided on the end surface of the axle 11 by a plurality of bolts 50. The connection is fixed. Then, concave portions and convex portions are formed alternately and at equal intervals in the circumferential direction on the outer peripheral edge portion of the holding plate 49, and the magnetic characteristics of this outer peripheral edge portion are alternately and equally spaced at equal intervals in the circumferential direction. Is changing. Further, the pressing plate 49 is provided with a function as a detected ring for detecting the rotation speed.
Other configurations and operations are the same as those of the above-described first example, and the description of the equivalent parts will be omitted.
[0036]
Next, FIG. 5 shows a fourth example of the embodiment of the present invention corresponding to claim 1. In the case of this example, the bearing box 12a is extended to the periphery of the holding plate 49, and the sensor mounting hole 46a is provided at an end of the bearing box 12a.
In the case of such a present example, processing of the sensor mounting seat surface and the sensor mounting hole 46a becomes troublesome, and the axial dimension of the bearing box 12a becomes large and heavy as compared with the case of the third example described above. Also, the work of attaching and detaching the sensor unit 31g to and from the sensor mounting hole 46a for maintenance / inspection work or the like may be somewhat troublesome. However, the heat transfer from the outer ring 5a constituting the double row rolling bearing 1a to the temperature sensor 21b is better than in the case of the third example described above.
Other configurations and operations are the same as those of the above-described third example, and therefore, the description of the equivalent parts will be omitted.
[0037]
Next, FIG. 6 shows a fifth example of the embodiment of the present invention corresponding to claim 1. In the case of this example, the diameter of the intermediate portion is made larger than the diameter of the tip portion of the holder 40e, and the outer peripheral surface of the holder 40e is stepped. Then, the temperature sensor 21b is installed in a portion close to the step existing near the tip of the holder 40e, and further, in order to improve the heat transfer to the temperature sensor 21b, the tip of the holder 40e and The step is covered with the same material (for example, iron) as the cover 9a. Furthermore, in the case of the present example, an acceleration sensor 2b for detecting vibration is incorporated in the holder 40e in addition to the rotation detection sensor 3e and the temperature sensor 21b to form a sensor unit 31h. The harness for extracting the signal of the acceleration sensor 2b is also bundled together with the harness for extracting the signals of the rotation detection sensor 3e and the temperature sensor 21b to form one cable 48a.
[0038]
Also in the case of this example, a harness for extracting the output signal of the rotation detection sensor 3e, a harness for extracting the output signal of the temperature sensor 21b, and the acceleration sensor 2b are provided in the single cable 48a. The harness for taking out the signal of the above is stored. Each of these harnesses is twisted with the ground wire, shielded individually, or a twisted pair twisted with the ground wire, as in the case of the first example described above. Or shielded. And, it prevents the signal currents flowing through the respective harnesses from interfering with each other.
[0039]
In the case of this example, a harness for sending a pulse-like signal such as a signal representing a rotation speed sent from the rotation detection sensor 3e and a signal representing a temperature or a vibration sent from the temperature sensor 21b and the acceleration sensor 2b. If a harness that sends such analog signals is bundled together, noise will appear on the analog signals due to electromagnetic coupling when the voltage or current of the pulse-like signal fluctuates. On the other hand, noise generated as described above can be prevented by twisting the individual harnesses with the ground wire, individually shielding the harness, or shielding the twisted pair twisted with the ground wire.
[0040]
In particular, in the case of a harness that transmits a signal having a small output, such as a signal indicating the vibration transmitted from the acceleration sensor 2b, since shielding or twisting has a large noise prevention effect, it is necessary to shield or twist. Is preferred. The effect of twisting with the shield and the ground line can be obtained by performing each independently, but by performing both together, a better noise prevention effect can be obtained. In this case, it is most preferable to collectively shield around the twisted pair in which the harness for transmitting the output signal and the ground wire are twisted from the viewpoint of the noise prevention effect. It is also possible to remove a certain amount of noise by providing a low-pass filter on the circuit portion of each of the sensors 3e, 21b, 2b and on the measuring instrument side.
[0041]
In addition, in the case of this example, since not only the temperature sensor 21b but also the acceleration sensor 2b functioning as a vibration sensor for detecting vibration is installed, abnormalities such as peeling of the rolling bearings such as the double row rolling bearing 1a are caused. When this occurs, the state of the peeling can be quickly detected. Therefore, a structure suitable for monitoring the abnormality of the rolling bearing can be realized as compared with the case where only the temperature sensor 21b is installed. In the case where both the monitoring of the abnormality of the rolling bearing and the monitoring of the rotation speed are to be performed, the rotation detection sensor 3e and the vibration sensor such as the temperature sensor 21b and the acceleration sensor 2b are used as in this example. It is most preferred to combine different types of sensors.
[0042]
However, the combination of the rotation detection sensor 3e and the vibration sensor such as the acceleration sensor 2b, or the combination of the rotation detection sensor 3e and the temperature sensor 21b also makes it possible to monitor the abnormality of the rolling bearing and the rotation speed. You can do both. On the other hand, when the purpose is only to monitor the abnormality of the rolling bearing, the temperature sensor 21b and the vibration sensor such as the acceleration sensor 2b may be combined, and the rotation detection sensor 3e may be omitted. In this case, it is not necessary to form irregularities on the outer peripheral edge of the flange 45. Further, even when the harness for transmitting the output signal of the temperature sensor 21b and the harness for transmitting the output signal of the vibration sensor such as the acceleration sensor 2b are combined, the value of the vibration detected by the vibration sensor (the output signal representing the vibration) Depending on the amplitude, it is preferable to twist the individual harnesses with the ground wire, shield them individually, or shield the twisted pair twisted with the ground wire as described above.
Other configurations and operations are the same as those of the above-described first example, and the description of the equivalent parts will be omitted.
[0043]
Next, FIG. 7 shows a sixth example of the embodiment of the present invention corresponding to claim 1. In the case of this example, the bearing box 12a is extended to the periphery of the annular member 16a, and the sensor mounting hole 46a is provided at an end of the bearing box 12a.
In the case of such a present example, processing of the sensor mounting seat surface and the sensor mounting hole 46a becomes troublesome, and the axial size of the bearing box 12a becomes large and heavy compared to the case of the fifth example described above. Also, the work of attaching and detaching the sensor unit 31h to and from the sensor mounting hole 46a for maintenance / inspection work or the like may be somewhat troublesome. However, the heat transfer from the outer ring 5a constituting the double row rolling bearing 1a to the temperature sensor 21b is better than in the case of the fifth example described above.
Other configurations and operations are the same as those of the above-described fifth example, and a description of equivalent parts will be omitted.
[0044]
Next, FIGS. 8 and 9 show a seventh example of the embodiment of the present invention corresponding to claim 2. FIG. The hub 22 formed in a hollow cylindrical shape, together with the inner ring element 18 described below, constitutes an inner ring described in claims. A wheel constituting a wheel and a disk rotor constituting a braking device are fixed to a flange 51 formed on an outer peripheral surface of an outer end portion of the hub 22 by a plurality of studs not shown. An outer inner raceway 6 is formed on the outer peripheral surface of the intermediate portion of such a hub 22, and the inner race element 18 having the inner inner raceway 6 on the outer peripheral surface is externally fixed to a step 23 formed at the inner end. ing. A spline shaft attached to a constant velocity joint (not shown) is inserted into a spline hole 24 formed in the center of the hub 22 in a state of being assembled to an automobile.
[0045]
On the other hand, around the hub 22 and the inner ring element 18, a double row of outer ring raceways 4, 4 on the inner peripheral surface, and the outer ring 5 formed with the mounting portion 25 on the outer peripheral surface, respectively, are attached to the hub 22 and the inner ring element 18. And are arranged concentrically. The mounting portion 25 is used to support and fix the outer ring 5 to a suspension device (not shown) such as a knuckle. A plurality of rolling elements 8, 8 are provided between the outer raceways 4, 4 and the inner raceways 6, 6, respectively. Wheels are provided on the inner diameter side of the outer race 5 fixed to the suspension device. The hub 22 and the inner ring element 18 for fixing the wheel including the above are rotatably supported. In the case of a heavy-duty rolling bearing unit for an automobile, tapered rollers may be used as the rolling elements 8 instead of balls as shown in the figure. Further, instead of forming the outer inner raceway 6 directly on the outer peripheral surface of the hub 22, the outer inner raceway 6 may be formed on the outer peripheral surface of a separate inner race.
[0046]
Seal rings 26 are mounted between the inner peripheral surfaces of both ends of the outer race 5, the outer peripheral surface of the intermediate portion of the hub 22, and the outer peripheral surface of the inner end of the inner race element 18, respectively. The openings at both ends of the space 27 in which the plurality of rolling elements 8 and 8 are provided are closed. The grease sealed in the space 27 is prevented from leaking to the outside, and foreign substances floating outside are prevented from entering the space 27.
[0047]
A cylindrical surface portion 28 is formed concentrically with the hub 22 on the outer peripheral surface of the intermediate portion of the hub 22 and between the outer inner raceway 6 and the step portion 23. The detected ring 10c is externally fitted and fixed to the cylindrical surface portion 28 by interference fit. The detected ring 10c is formed in a cylindrical shape entirely from a magnetic all-metal plate such as a steel plate such as SPCC. A large number of through-holes 29, 29 functioning as a wall-thinning portion are formed in the middle portion in the axial direction. They are formed at equal intervals in the circumferential direction. Each of the through holes 29 has a slit shape that is long in the axial direction (the left-right direction in FIG. 8). Further, a portion between the through holes 29 adjacent to each other in the circumferential direction is a pillar portion functioning as a solid portion. With this configuration, the magnetic characteristics of the outer peripheral surface in the axial direction intermediate portion of the detected ring 10c are alternately changed at equal intervals in the circumferential direction.
[0048]
On the other hand, a mounting hole 30 is formed in a portion facing the outer peripheral surface of the detected ring 10c at an axially intermediate portion of the outer ring 5 so as to penetrate from the outer peripheral surface to the inner peripheral surface of the outer ring 5. . Then, the sensor unit 31 is inserted into the mounting hole 30 from the outer diameter side opening, and the distal end surface (the lower end surface in FIG. 8) of the sensor unit 31 is closely opposed to the outer peripheral surface of the detected ring 10c. . In this manner, in order to allow the sensor unit 31 to be freely inserted into the mounting hole 30, the mounting portion 25 is discontinuous around the outer diameter side opening of the mounting hole 30, and the mounting seat 32 is replaced with the mounting seat 32. It is formed on the outer peripheral surface of the outer ring 5. The sensor unit 31 is fixed to the outer race 5 by screwing a flange 33 provided at a base end (upper end in FIG. 8) to the mounting seat 32. An O-ring 34 seals between the inner peripheral surface of the mounting hole 30 and the outer peripheral surface of the sensor unit 31.
[0049]
As shown in FIG. 9, the sensor unit 31 has a rotation detection sensor 3c and a temperature sensor 21a installed (embedded and supported) in a holder (case) 40 made of a synthetic resin. Among them, the rotation detection sensor 3c is a magnetic detection element 36 that changes its characteristic according to the amount of magnetic flux passing through a Hall element, an MR element, and the like, and a source of magnetic flux passing through the magnetic detection element 36 in FIG. This is a so-called active type sensor comprising a permanent magnet 37 magnetized in the up-down direction and a waveform shaping circuit 38 for adjusting the waveform of a signal accompanying the characteristic change of the magnetic detecting element 36 (to make a rectangular wave).
[0050]
The magnetic detecting element 36 is made to closely approach the outer peripheral surface of the detected ring 10c in the axial middle part via the gap 39. The thickness T in the radial direction of the gap 39 ₃₉ Is regulated within the range of 0.5 to 6 mm (T ₃₉ = 0.5-6 mm). The reason for this is to ensure the performance of the rotation speed detection by the rotation detection sensor 3c and to improve the assemblability of the double row rolling bearing with the sensor unit of the present embodiment.
[0051]
That is, the present inventor has determined that the thickness T ₃₉ Were prepared in the range of 0.1 to 8 mm, and an experiment was conducted to confirm the performance of the above-described rotation speed detection and the assemblability. Results were obtained. In Table 2, the symbol “○” indicates that the performance or assemblability of the rotational speed detection was good, and the symbol “△” indicates that the detection performance was slightly poor, and the symbol “×” Indicates that the rotation detection performance was poor, and the assemblability was that the tip of the rotation detection sensor 3c contacted the detected ring 10c with the rotation of the hub 22 and the inner ring element 18. , Respectively.
[0052]
[Table 2]

From Table 2, the thickness T ₃₉ Is restricted to the range of 0.5 to 6 mm, it can be understood that the performance of the rotation speed detection is secured and the assemblability of the double row rolling bearing 1 can be improved.
[0053]
The thermistor, which is the temperature sensor 21a, is embedded and supported at the tip of the holder 40 so that the temperature in the space 27 in which the rolling elements 8, 8 are installed can be detected. The detection signals of the rotation detection sensor 3c and the temperature sensor 21a constituting such a sensor unit 31 are taken out through a harness 41 derived from the base end face of the holder 40 and sent to a controller (not shown).
[0054]
The rotation detection sensor 3c included in the sensor unit 31 described above detects one or both of the rotation speed and the number of rotations of the wheel as follows. When the detected ring 10c externally fixed to the hub 22 rotates with the rotation of the wheel, a portion near the magnetic detection element 36 is formed in a through hole 29 formed in an axially intermediate portion of the detected ring 10c. 29 and the pillars present between the circumferentially adjacent through holes 29, 29 alternately pass through. As a result, the amount of magnetic flux flowing in the magnetic detecting element 36 changes, and the output of the rotation detecting sensor 3c changes. Since the frequency at which this output changes is proportional to the rotational speed of the wheel, if an output signal is input to a controller (not shown) through the harness 41, the rotational speed of the wheel can be obtained and the ABS and TCS can be appropriately controlled. . In addition, the number of rotations of the wheel is determined by the number of times the output changes, and the traveling distance can be determined from the number of rotations.
[0055]
On the other hand, the temperature sensor 21a detects the temperature in the space 27 inside the wheel supporting rolling bearing unit, and sends the temperature to the controller (not shown) through the harness 41 as well. Then, it is possible to know the temperature rise of the rolling bearing unit for wheel support and the overheating state of the brake. The rise in the temperature of the wheel supporting rolling bearing unit is not only important data for knowing the life of the wheel supporting rolling bearing unit itself, but also knowing the overheated state of the brake part and causing dangerous It can be used to alert the driver before the condition appears.
[0056]
Since the overheated state of the brake portion is transmitted from the disk rotor to the hub 22, it is preferable that the temperature sensor 21a is installed on the distal end surface of the sensor unit 31 and is closely opposed to the hub 22. On the other hand, the temperature rise of the wheel supporting rolling bearing unit can be known from the temperature of the outer ring 5. In order to measure the temperature of the outer ring 5, the temperature sensor 21a can be installed at a portion of the holder 40 at a portion facing the inner peripheral surface of the mounting hole 30 at an intermediate portion. In any case, by arranging the temperature sensor 21a close to or in contact with the measured portion, the temperature of the measured portion can be accurately measured, and an abnormality of the wheel supporting rolling bearing unit or an overheating state of the brake can be achieved. Can be detected early and an alarm can be issued.
[0057]
Moreover, since the temperature sensor 21a is embedded and supported in the same holder 40 as that holding the rotation detection sensor 3c, the weight and the mounting space of the temperature sensor 21a increase and the number of assembling steps increases. Therefore, the manufacturing cost of the vehicle is not increased unnecessarily. Further, even if the detection signal of each of the sensors 3c and 21a is sent to the controller, the detection signal can be collected into one harness 41 housed in the same covering, so that the weight of the harness 41 can be reduced and the wiring work can be reduced. Can be simplified.
[0058]
Next, FIG. 10 shows an eighth example of the embodiment of the present invention corresponding to claim 2. The sensor unit 31a used in the present example includes a magnetic detection element 36, a permanent magnet 37, a waveform shaping circuit 38, and an acceleration sensor 2a, each of which constitutes a rotation detection sensor 3c in a synthetic resin holder 40a. The embedding is supported. The acceleration sensor 2a functions as a vibration sensor for measuring the vibration of the double row rolling bearing portion. For example, a small acceleration sensor using a piezoelectric element and a signal processing circuit are mounted on the substrate 42. , And molded in the holder 40a. As shown in FIG. 10, such an acceleration sensor 2a is provided with the magnetic detecting element 36 and the permanent magnet with respect to the axial direction of the holder 40a (vertical direction in FIG. 10) in order to reduce the size of the entire sensor unit 31a. It is preferable to install in series with the magnet 37 on the base end side (upper side in FIG. 10) of these two members.
[0059]
A structure in which the sensor unit 31a as described above is fixed to the outer ring 5 (see FIG. 8) constituting a double-row rolling bearing for supporting wheels, and further, the output signals of the sensors 3c and 2a are taken out. The operation of detecting the rotation speed of the wheel by the rotation detection sensor 3c is the same as that of the above-described seventh example.
In particular, in the case of this example, the acceleration sensor 2a is embedded in a holder 40a made of synthetic resin to be integrated with the sensor unit 31a, and the sensor unit 31a is fixed to the outer ring 5 without rattling. Therefore, the vibration of the outer ring 5 can be accurately measured. Since the vibration transmitted from the wheel to the hub 22 is transmitted to the outer wheel 5 through the rolling elements 8 and 8 (see FIG. 8), the signal output from the acceleration sensor 2a is input to a controller (not shown). It is possible to know the unevenness of the road surface on which the wheel is in contact with the ground, the air pressure of the tire, the acceleration / deceleration status, and the like. Then, the damping amount of the damper incorporated in the suspension device can be automatically adjusted, and the output of the engine can be adjusted. Further, it is possible to detect an abnormal vibration generated when the life of the rolling bearing unit for supporting the wheel has reached the end of its life, and to issue a warning to the driver.
[0060]
The direction of the vibration detected by the acceleration sensor 2a can be freely adjusted by regulating the direction of the acceleration sensor 2a in a state where the wheel supporting rolling bearing unit is supported by a suspension device (installed state). It is. For example, considering the case where the acceleration sensor 2a is configured by a general piezoelectric element, the directions of vibration that can be detected by the acceleration sensor 2a are the a-axis, b-axis, and c-axis shown in FIG. In either direction. Vibration in a direction perpendicular to each of these axes is hardly detected, and components of the vibration applied to each of these axes in a tilt direction are components parallel to each of these axes.
[0061]
11 (B) and 11 (C) are set as installation states, and with respect to FIGS. 11 (B) and 11 (C), the X direction is the width direction of the vehicle, the Y direction is the front-rear direction of the vehicle, and the Z direction is the vertical direction of the vehicle. Think about the direction. Note that arrows shown in the acceleration sensor 2a in FIGS. 11B and 11C indicate directions of vibration detected by the acceleration sensor 2a. First, as shown in FIG. 11B, when the detection direction of the acceleration sensor 2a is made to coincide with the Z direction, the vibration in the vertical direction of the vehicle can be effectively detected, and the traveling direction and the width of the vehicle can be detected. No directional vibration is detected. The vibration applied in the direction inclined with respect to the vertical direction detects the vertical component of the vibration. Next, as shown in FIG. 11C, when the detection direction of the acceleration sensor 2a is made to coincide with the Y direction, vibration in the front-rear direction of the vehicle can be effectively detected, and No directional vibration is detected. In addition, the vibration applied in the direction inclined with respect to the front-back direction detects the component in the front-back direction. In FIG. 11, reference numeral 44 denotes a signal processing circuit for processing a detection signal of the vibration sensor.
[0062]
Next, FIG. 12 shows a ninth embodiment of the present invention corresponding to claim 2. The sensor unit 31b used in this example embeds and supports the temperature sensor 21a and the acceleration sensor 2a in addition to the rotation detection sensor 3c in a synthetic resin holder 40b. The operation of the temperature sensor 21a is the same as that of the above-described seventh example, and the operation of the acceleration sensor 2a is the same as that of the above-described eighth example. The description of the operation will be omitted.
[0063]
Next, FIG. 13 shows a tenth example of the embodiment of the present invention corresponding to claims 1 and 2. The sensor unit 31c used in the present example is configured such that a synthetic resin holder 40c in which the rotation detection sensor 3c, the temperature sensor 21a, and the acceleration sensor 2a are embedded is made of a nonmagnetic metal such as aluminum, copper, or nonmagnetic stainless steel. It is held in a case 43 made of. By providing such a case 43, the strength of the sensor unit 31c is improved, and the rotation detection sensor 3c is hardly affected by an external magnetic flux. Further, by installing the temperature sensor 21a in contact with the case 43, the temperature detection performance of the temperature sensor 21a is improved. The structure in which such a case 43 is provided can be combined with the structure of the seventh example shown in FIG. 9 or the structure of the ninth example shown in FIG.
[0064]
Next, FIGS. 14 and 15 show an eleventh embodiment of the present invention corresponding to claim 2. FIG. In the case of this example, a permanent magnet ring is used as the detected ring 10d externally fitted and fixed to the hub 22 to detect the rotation speed of the hub 22. The detected ring 10d is formed by adhering an encoder body made of a rubber magnet mixed with ferrite powder, rare earth magnet powder, or the like over the entire circumference to the outer peripheral surface of a cylindrical cored bar. The encoder body may be a plastic magnet or a bonded magnet. The core metal may be made of various metals or synthetic resin, but if it is made of a magnetic metal plate such as a carbon steel plate, the strength of the magnetic flux emitted from the outer peripheral surface of the encoder body can be increased, and It is preferable to widen the gap 39 between the outer peripheral surface and the detection portion of the rotation detection sensor 3d installed in the holder 40, because the reliability of rotation detection can be ensured. Further, the ring to be detected 10d may be configured by directly fixing the encoder main body to the outer diameter surface of the hub 22 by resin molding or bonding without providing a cored bar.
[0065]
In any case, the encoder main body is magnetized in the diameter direction, and the magnetization directions are alternately changed at equal intervals in the circumferential direction. Therefore, S poles and N poles are alternately arranged at equal intervals in the circumferential direction on the outer peripheral surface of the detected ring 10d. In general, the magnetization patterns of the encoder main body are alternately and equally spaced, but it is not always necessary. For example, as described in Japanese Patent Application Laid-Open No. 2000-334673, if a magnetization pattern that alternately repeats the S-pole, the N-pole, and the non-magnetized region is adopted, not only the rotation speed but also the rotation direction can be improved. Detection is also possible. In short, a desired magnetization pattern may be adopted according to the required function.
[0066]
In any case, the permanent magnet 37 as shown in FIG. 9 is provided in the sensor unit 31c mounted in the mounting hole 30 of the outer ring 5 in accordance with the use of the permanent magnet as the detected ring 10d. Not. That is, the magnetic sensor 36 and the waveform shaping circuit 38 serving as the rotation detecting sensor 3d and the temperature sensor 21a are installed (embedded) in the sensor unit 31c. The configuration and operation of the other parts are the same as those of the above-described seventh example shown in FIGS. 8 and 9, and therefore, the same reference numerals are given to the same parts, and redundant description will be omitted.
[0067]
Next, FIG. 16 shows a twelfth example of the embodiment of the present invention corresponding to claim 2. The sensor unit 31d used in this example embeds and supports the acceleration sensor 2a in a synthetic resin holder 40a in addition to the magnetic detection element 36 and the waveform shaping circuit 38 for configuring the rotation detection sensor 3d. ing. This is the same as the above-described eighth example shown in FIG. 10 except that a permanent magnet is not incorporated in the rotation detection sensor 3d in accordance with the use of a permanent magnet as the detected ring 10d (see FIG. 14). Therefore, the same reference numerals are given to the same parts, and the duplicate description will be omitted.
[0068]
Next, FIG. 17 shows a thirteenth embodiment of the present invention corresponding to claim 2. The sensor unit 31e used in this example embeds and supports a temperature sensor 21a and an acceleration sensor 2a in addition to a rotation detection sensor 3d in a synthetic resin holder 40b. This is the same as the above-described ninth example shown in FIG. 12 except that a permanent magnet is not incorporated in the rotation detection sensor 3d in accordance with the use of a permanent magnet as the detected ring 10d (see FIG. 14). Therefore, the same reference numerals are given to the same parts, and the overlapping description will be omitted.
[0069]
Next, FIG. 18 shows a fourteenth example of the embodiment of the present invention corresponding to the first and second aspects. The sensor unit 31f used in this example includes a synthetic resin holder 40c in which the rotation detection sensor 3d and the acceleration sensor 2a are embedded in a case 43 made of a non-magnetic metal such as aluminum, copper, or non-magnetic stainless steel. keeping. This is the same as the above-described tenth example shown in FIG. 13 except that a permanent magnet is not incorporated in the rotation detection sensor 3d in accordance with the use of a permanent magnet as the detected ring 10d (see FIG. 14). Therefore, the same reference numerals are given to the same parts, and the overlapping description will be omitted.
[0070]
【The invention's effect】
Since the present invention is configured and operates as described above, it is possible to realize a double row rolling bearing with a sensor unit capable of accurately measuring two or more different state values such as a rotation speed, vibration, and temperature.
[Brief description of the drawings]
FIG. 1 is a sectional view taken along line AA of FIG. 2, showing a first example of an embodiment of the present invention.
FIG. 2 is a view as seen from the left side of FIG. 1;
FIG. 3 is an essential part cross-sectional view showing a second example of the embodiment of the present invention.
FIG. 4 is an essential part cross-sectional view showing the third example.
FIG. 5 is an essential part cross-sectional view showing the fourth example.
FIG. 6 is an essential part cross-sectional view showing the fifth example.
FIG. 7 is a sectional view of a principal part showing the sixth example.
FIG. 8 is a sectional view showing a seventh example.
FIG. 9 is a sectional view of a sensor unit incorporated in the seventh example.
FIG. 10 is a sectional view of a sensor unit incorporated in the eighth example.
FIG. 11 is a perspective view for explaining an installation state when a vibration sensor capable of detecting only one-directional vibration is used.
FIG. 12 is a sectional view of a sensor unit incorporated in a ninth embodiment of the present invention.
FIG. 13 is a sectional view of a sensor unit incorporated in the tenth example.
FIG. 14 is a sectional view showing the eleventh example.
FIG. 15 is a sectional view of a sensor unit incorporated in the eleventh example.
FIG. 16 is a sectional view of a sensor unit incorporated in the twelfth example.
FIG. 17 is a sectional view of a sensor unit incorporated in the thirteenth example.
FIG. 18 is a sectional view of a sensor unit incorporated in the fourteenth example.
FIG. 19 is a sectional view showing a first example of a conventional structure.
FIG. 20 is a sectional view taken along line BB of FIG. 19;
FIG. 21 is a sectional view taken along the line COD of FIG. 22, showing a second example of the conventional structure.
FIG. 22 is a view as seen from the left side of FIG. 21;
FIG. 23 is a sectional view showing a third example of the conventional structure.
[Explanation of symbols]
1,1a, 1b double row rolling bearing
2, 2a, 2b acceleration sensor
3, 3a, 3b, 3c, 3d, 3e rotation detection sensor
4, 4a Outer ring track
5, 5a Outer ring
6, 6a Inner ring track
7, 7a Inner ring
8, 8a rolling element
9, 9a cover
10, 10a, 10b, 10c, 10d Detected ring
11 axles
12 Bearing housing
13 Cage
14 Inner ring element
15 room
16, 16a annular member
17 nut
18 Inner ring element
19, 19a cylindrical part
20 recess for sensor mounting
21, 21a, 21b Temperature sensor
22 hub
23 steps
24 spline holes
25 Mounting part
26 Seal ring
27 Space
28 Cylindrical surface
29 through hole
30 mounting holes
31, 31a, 31b, 31c, 31d, 31e, 31f, 31g, 31h Sensor unit
32 Mounting seat
33 flange
34, 34a O-ring
35 Mounting flange
36 Magnetic sensing element
37 permanent magnet
38 Waveform shaping circuit
39, 39a gap
40, 40a, 40b, 40c, 40d, 40e Holder
41 Harness
42 substrate
43 cases
44 signal processing circuit
45 Tsuba
46, 46a Sensor mounting hole
47 volts
48, 48a cable
49 Holding plate
50 volts
51 Flange

Claims (2)

An outer ring having a double row of outer ring raceways on the inner peripheral surface, an inner ring having a double row of inner ring raceway on the outer peripheral surface, and a plurality of rolling elements rotatably provided between each of the outer ring raceways and each of the inner ring raceways. A moving body, a detected ring fixed to one of the outer races and the inner raceway directly or via another member, and a plurality of sensors for detecting states different from each other are made of a material having good heat conductivity. A sensor unit that is held in a case made by the method described above, and the other of the outer ring and the inner ring is provided in a space that is isolated from the outside while facing the detected ring. Double row rolling bearing with a sensor unit provided on the raceway of the above in a state of being supported directly or via another member. An outer ring having a double row of outer ring raceways on the inner peripheral surface, an inner ring having a double row of inner ring raceway on the outer peripheral surface, and a plurality of rolling elements rotatably provided between each of the outer ring raceways and each of the inner ring raceways. A sensor unit comprising: a moving body, a detected ring directly fixed to the inner ring, and a plurality of sensors for detecting different states, and a sensor unit directly supported by the outer ring in a state facing the detected ring. Double row rolling bearings.

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