JP2004101312A - Magnetic encoder with original position, and bearing - Google Patents

Magnetic encoder with original position, and bearing Download PDF

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Publication number
JP2004101312A
JP2004101312A JP2002262261A JP2002262261A JP2004101312A JP 2004101312 A JP2004101312 A JP 2004101312A JP 2002262261 A JP2002262261 A JP 2002262261A JP 2002262261 A JP2002262261 A JP 2002262261A JP 2004101312 A JP2004101312 A JP 2004101312A
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Japan
Prior art keywords
detected
magnetic
origin
detected portion
magnetic encoder
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JP2002262261A
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Japanese (ja)
Inventor
Kenichi Iwamoto
岩本　憲市
Takashi Koike
小池　孝誌
Tomoumi Ishikawa
石河　智海
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NTN Corp
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NTN Corp
NTN Toyo Bearing Co Ltd
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Priority to JP2002262261A priority Critical patent/JP2004101312A/en
Publication of JP2004101312A publication Critical patent/JP2004101312A/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C41/00—Other accessories, e.g. devices integrated in the bearing not relating to the bearing function as such
    • F16C41/007—Encoders, e.g. parts with a plurality of alternating magnetic poles
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
    • F16C19/02—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows
    • F16C19/04—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for radial load mainly
    • F16C19/06—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for radial load mainly with a single row or balls
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C41/00—Other accessories, e.g. devices integrated in the bearing not relating to the bearing function as such
    • F16C41/008—Identification means, e.g. markings, RFID-tags; Data transfer means

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic encoder, wherein the formation of a part to be detected for a rotating pulse signal and original position detection and magnetization are enabled simultaneously, manufacture is simple and cost is low. <P>SOLUTION: The magnetic encoder 7, having original position, is used for rotation detection and provided with a first part 7A to be detected and a second part 7B to be detected which are mutually concentric. The first part 7A has a constant thickness for each part in the circumferential direction and is a permanent magnet, wherein a plurality of magnetic poles N, S arranged in circumference direction are formed. The second part 7B is connected with the first part 7A. Only one part on the circumference has the same thickness as that of the first part 7A and is set as a wall thickness part 7Ba having a magnetic pole. The other part of the second part 7B is a thin wall part 7Bb which is thinner than the thick wall part 7Ba. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
この発明は、モータの制御やロボットの関節等に用いることのできる原点付き磁気エンコーダ、およびこの磁気エンコーダを内蔵した回転検出機能付き軸受に関する。
【０００２】
【従来の技術】
回転パルス信号と１回転に１回の原点信号とを出力するための磁気エンコーダの例として、例えば特許文献１に示すものがある。図９，図１０に示すように、この例の磁気エンコーダ３７では、回転パルス信号を得るために、円周方向に同一ピッチで多極着磁されている第１の被検出部３７Ａと、円周方向の１箇所にのみ、他の部分とは異なる磁極を配置し、原点信号を得る第２の被検出部３７Ｂからなる構成とされている。第１の被検出部３７Ａに対向して２つの磁気センサ３８Ａ，３８Ｂが、磁極ピッチの９０°分の位相をずらせて配置され、回転方向の検出も可能とされている。磁気エンコーダ３７は、軸受３１における回転輪３２に取付けられ、固定輪３３に各磁気センサ３８Ａ〜３８Ｃが設置されている。
【０００３】
【特許文献１】
特開平１１−１９４００９号公報
【０００４】
【発明が解決しようとする課題】
上記従来の磁気エンコーダ３７では、パルス信号と原点検出のための被検出部３７Ａ，３７Ｂの作成および着磁を別々に行うことになるため、製造が煩雑である。そのためコスト高になる。
【０００５】
この発明の目的は、回転パルス信号と原点検出のための被検出部の作成および着磁が同時に行えて、製造が簡便であり、安価にできる原点付き磁気エンコーダ、および回転検出機能付き軸受を提供することである。
【０００６】
【課題を解決するための手段】
この発明における第１の発明の原点付き磁気エンコーダは、回転検出に用いられる原点付き磁気エンコーダであって、互いに同心のリング状の第１の被検出部および第２の被検出部を有する。第１の被検出部は、円周方向の各部の厚さが一定で、円周方向に並ぶ複数の磁極が形成された永久磁石である。第２の被検出部は、第１の被検出部と繋がっていて、円周上の１箇所のみ第１の被検出部と厚さが同一でかつ磁極を有する厚肉部分とされ、他の部分が上記厚肉部分よりも薄い薄肉部分である。上記第１の被検出部および第２の被検出部は、例えば円筒状とされる。
この構成によると、第１の被検出部は円周方向に並ぶ磁極より回転パルス信号の検出が可能であり、第２の被検出部は円周上の１箇所の磁極により原点検出に用いられる。第１，第２の被検出部は互いに繋がっているため、着磁前までの作成が同時に行える。着磁についても、第２の被検出部は磁極形成部分が第１の被検出部と同じ厚肉部分であって、他の部分が薄肉部分とされているため、第１の被検出部と同時に全周に着磁のための磁界付与を行っても、薄肉部分はギャップが広くなることや、磁石となる部分の厚さが薄いことなどにより着磁強度が低くなる。そのため、薄肉部分は検出対象として無視できる着磁強度にでき、未着磁と同等に扱える。したがって、両被検出部の着磁が同時に行える。このように、回転パルス信号と原点検出のための被検出部の作成および着磁が同時に行えて、製造が簡便であり、安価にできる。また原点検出のための被検出部が独立した磁石でないため、芯金を用いる場合にその芯金への強固な接合が可能である。さらに、回転パルス信号と原点検出のための被検出部が一体であるため、コンパクトになる。
【０００７】
上記第２の被検出部における上記厚肉部分の円周方向の幅寸法は、磁極幅と概ね同等以上でかつ３倍よりも小さいものとするのが好ましい。幅寸法が磁極幅より狭くなると、磁極検出信号自体が低くなり、また幅寸法が磁極幅の３倍を超えると、１回転に２つ以上の原点信号が発生する可能性がある。そのため、この範囲の幅寸法が好ましい。
第２の被検出部における厚肉部分と薄肉部分との段差は０．５ｍｍ以上とすることが好ましい。この段差が０．５ｍｍ以上であると、第１，第２の被検出部の同時着磁で薄肉部分の着磁強度がセンサ出力に影響しないようにすることが容易である。
第１の被検出部および第２の被検出部はゴム磁石であっても良い。ゴム磁石はこの種の磁気エンコーダに製造上や性能上の種々の利点があるが、ゴム磁石においても、第２の被検出部を厚肉部分と薄肉部分とで構成したことによる同時作成，同時着磁が容易に行える。
【０００８】
この発明における回転検出機能付き軸受は、転動体を介して互いに回転自在な回転輪および静止輪と、上記回転輪に設けられた磁気エンコーダとを備え、この磁気エンコーダにこの発明の上記いずれかの構成の原点付き磁気エンコーダを用いたものである。
この構成によると、回転数検出だけでなく、原点検出も可能でかつ回転方向も検出できる回転検出機能付き軸受でありながら、回転数検出センサと原点検出センサを個別に設置する必要がなく、組立が簡単で、簡素でコンパクトな構造とすることができる。また、この発明の原点付き磁気エンコーダにおける製造簡便の効果により、高機能で安価な軸受とできる。
【０００９】
この軸受において、原点付き磁気エンコーダにおける第２の被検出部の厚肉部分と円周方向位置が一致する原点位置表示マークを回転輪に設け、上記第２の被検出部を検出するセンサの円周方向の取付位置を示すセンサ取付位置表示マークを静止輪に設けても良い。
このように各表示マークを施すと、磁気エンコーダやセンサが内蔵されて外部から見えなくても、原点位置表示マークおよびセンサ取付位置表示マークを見ることで、磁気エンコーダの原点位置およびセンサ位置を、軸やハウジングに正しく組み込むことができ、軸受の組み込み作業が容易に精度良く行える。
上記原点位置表示マークおよびセンサ取付位置表示マークは刻印であっても良い。刻印であると、容易に施すことができ、かつ消え難い。
また、この発明の回転検出機能付き軸受において、上記第１の被検出部を検出するセンサおよび第２の被検出部を検出するセンサをセンサケースに設け、このセンサケースに、第２の被検出部の円周方向位置を示す表示マークを設けても良い。センサケースに第２の被検出部の円周方向位置を示しておいた場合も、第２の被検出部が外部から直接に見えなくても、軸受のハウジングへの組み込みが、センサ位置が正しく、容易に行える。
【００１０】
この発明の原点付き磁気エンコーダの製造方法は、回転検出に用いられる原点付き磁気エンコーダの製造方法であって、互いに同心のリング状の第１の被検出部および第２の被検出部を有し、第１の被検出部は円周方向の各部の厚さが一定であり、第２の被検出部は第１の被検出部と繋がっていて、円周上の１箇所のみ第１の被検出部と厚さが同一の厚肉部分とされ、他の部分が上記厚肉部分よりも薄い薄肉部分である未着磁エンコーダ素材を製造する過程と、この未着磁エンコーダ素材の第１の被検出部に円周方向に並べて設ける複数の磁極、および第２の被検出部の厚肉部分に設ける磁極を同時に着磁する過程とを含む方法である。
この製造方法によると、第１の被検出部に円周方向に並べて複数の磁極Ｎ，Ｓが着磁されると同時に、第２の被検出部にも円周方向に並べて複数の磁極Ｎ，Ｓが着磁されるが、第２の被検出部では、厚肉部分において第１の被検出部と同じ磁力の磁極が着磁されるのに対して、薄肉部分においては、肉厚が薄いこと、および着磁時のギャップが大きい等の理由により、着磁強度が第１の被検出部に比べてかなり小さくなり、検出対象として無視できる磁力となる。これにより、第２の被検出部では、厚肉部分にのみ磁極が着磁されたと同等の結果が得られ、第１の被検出部と第２の被検出部の着磁を同時に行うことができる。
【００１１】
【発明の実施の形態】
この発明の第１の実施形態を図１ないし図５と共に説明する。図１は、この実施形態の原点付き磁気エンコーダを内蔵した回転検出機能付き軸受の断面図を示す。この回転検出機能付き軸受１は、転動体４を介して互いに回転自在な回転輪２および静止輪３を有するものであって、回転輪２に設けた原点付き磁気エンコーダ７と、静止輪３に設けた３つの磁気センサ８Ａ，８Ｂ，８Ｃとで回転センサ６を構成している。回転輪２は内輪とされ、静止輪３は外輪とされている。内輪からなる回転輪２の外径面、および外輪からなる静止輪３の内径面には転動体４の軌道面２ａ，３ａが形成されている。転動体４は保持器５で保持されている。回転輪２と静止輪３の間の環状空間は、回転センサ６の設置側とは反対側の端部がシール部材９で密封されている。
【００１２】
回転センサ６を構成する磁気エンコーダ７はラジアル型のものであって、図２に示すように周方向に多極磁化された環状とされる。具体的には、環状のバックメタル１０と、その外周側に設けられた２つの被検出部７Ａ，７Ｂを有する。この磁気エンコーダ７はバックメタル１０を介して回転輪２に固着されている。
上記両被検出部７Ａ，７Ｂは、互いに同心のリング状、具体的には円筒状とされる。第１の被検出部７Ａは円周方向の各部の厚さが一定で、円周方向に等間隔で交互に並ぶ複数の磁極Ｎ，Ｓが形成された永久磁石である。第２の被検出部７Ｂは第１の被検出部７Ａと繋がっていて、円周上の１箇所のみ第１の被検出部７Ａと厚さが同一で、かつ磁極を有する厚肉部分７Ｂａとされ、他の部分が上記厚肉部分７Ｂａよりも薄い薄肉部分７Ｂｂとされている。ここでは、上記両被検出部７Ａ，７Ｂはゴム磁石からなる。
【００１３】
第２の被検出部７Ｂにおける上記厚肉部分７Ｂａの円周方向の幅寸法Ｗは、磁極幅と概ね同等とされているが、図３（Ｃ）に示すように磁極幅の略３倍としても良い。厚肉部分７Ｂａの円周方向の幅寸法Ｗが磁極幅より狭くなると、厚肉部分７Ｂａの磁極の検出信号自体が低くなり、また上記幅寸法Ｗが磁極幅の３倍を超えると、回転輪２が１回転する間に２つ以上の原点信号が発生する可能性があるため、上記幅寸法Ｗは磁極幅と概ね同等以上でかつ３倍より小さくするのが好ましい。これにより、回転輪２が１回転する間に、第２の被検出部７Ｂが確実に１つの原点信号を発生することになり、原点位置の検出を正確に行うことができる。第２の被検出部７Ｂにおける厚肉部分７Ｂａと薄肉部分７Ｂｂとの段差ｄは０，５ｍｍ以上とするのが好ましい。
【００１４】
磁気センサ８Ａ，８Ｂ，８Ｃは例えばホール素子からなる。これらの磁気センサ８Ａ，８Ｂ，８Ｃは、回転輪２の回転により、対向する磁気エンコーダ７の磁極Ｎ，Ｓの変化に対応して、インクリメンタルなパルス信号を出力する。１組となる２つの磁気センサ８Ａ，８Ｂと他の１つの磁気センサ８Ｃとは、軸方向に分けて配置され、１組の磁気センサ８Ａ，８Ｂとこれに対向する磁気エンコーダ７の第１の被検出部７Ａとで第１の回転センサ部１１が構成される。また、他の１つの磁気センサ８Ｃとこれに対向する第２の被検出部７Ｂとで第２の回転センサ部１２が構成される。すなわち、１つの磁気エンコーダ７において、第１の被検出部７Ａと第２の被検出部７Ｂが軸方向に並べた状態に配置される。このように１つの磁気エンコーダ７に２つの被検出部７Ａ，７Ｂを軸方向に並べて配置し、また肉厚差を持たせることにより、両被検出部７Ａ，７Ｂの着磁を同時に行うことができ、着磁のタクトタイムを短縮して、製造費用を削減することができる。また、第１の被検出部７Ａと第２の被検出部７Ｂとは、磁極配列の繰り返し周期における位相を等しくしており、その着磁作業をより簡単に行うことができる。
【００１５】
特に、第１の被検出部７Ａは円周方向の各部の厚さが一定であり、第２の被検出部７Ｂは第１の被検出部７Ａと繋がっていて、円周上の１箇所のみ第１の被検出部７Ａと厚さが同一の厚肉部分７Ｂａとされ、他の部分が上記厚肉部分７Ｂａよりも薄い薄肉部分７Ｂｂとされているので、両被検出部７Ａ，７Ｂの着磁を以下のように１工程で同時に行うことができる。
すなわち、上記肉厚構造とした第１の被検出部７Ａおよび第２の被検出部７Ｂを一体に有する未着磁エンコーダ素材に対して、複数の磁極Ｎ，Ｓを円周方向に並べて着磁する。これにより、第１の被検出部７Ａに円周方向に並べて複数の磁極Ｎ，Ｓが着磁されると同時に、第２の被検出部７Ｂにも円周方向に並べて複数の磁極Ｎ，Ｓが着磁される。しかし、第２の被検出部７Ｂでは、厚肉部分７Ｂａにおいて第１の被検出部７Ａと同じ磁力の磁極が着磁されるのに対して、他の薄肉部分７Ｂｂにおいては、肉厚が薄いこと、および着磁時のギャップが大きい等の理由により、着磁強度が第１の被検出部７Ａに比べてかなり小さくなり、検出対象として無視できる磁力となる。これにより、第２の被検出部７Ｂでは、厚肉部分７Ｂａにのみ磁極が着磁されたと同等の結果が得られる。このように、第１の被検出部７Ａと第２の被検出部７Ｂの着磁を同時に行えるので、上記エンコーダ７を容易に製造できコスト低減が可能となる。また、第１の被検出部７Ａと第２の被検出部７Ｂが分離独立していないので、バックメタル１０への強固な接合も可能となるばかりか、コンパクトに磁気エンコーダ７を構成できる。
【００１６】
上記３つの磁気センサ８Ａ，８Ｂ，８Ｃは、樹脂ケース１３内に挿入した後に樹脂モールドし、その樹脂ケース１３を金属ケース１４を介して静止輪３に固定することにより、静止輪３側に取り付けている。
【００１７】
図３（Ａ）は、第１の被検出部７Ａと１組の磁気センサ８Ａ，８Ｂとの位置関係を示し、図３（Ｂ）は第２の被検出部７Ｂと１つの磁気センサ８Ｃとの位置関係を示す。第２の被検出部７Ｂでは、その厚肉部分７Ｂａに１つの磁極Ｎが着磁されている。また、磁気センサ８Ａ，８Ｂの間では、磁極配列の繰り返し周期における位相の関係が、略９０°の位相差を有する位置関係とされている。
図３（Ｂ）では、第２の被検出部７Ｂの厚肉部分７Ｂａに１つの磁極Ｎが着磁された例を示しているが、厚肉部分７Ｂｂの幅Ｗが磁極幅の３倍弱である場合には、図３（Ｃ）に示すように厚肉部分７Ｂａにおいて、周方向に並ぶ３つの磁極（例えばＳ，Ｎ，Ｓ）が着磁されることになる。
【００１８】
図４は、回転センサ６からの出力信号を示す波形図である。図４（Ａ）は磁気センサ８Ａからの出力信号波形を、図４（Ｂ）は磁気センサ８Ｂからの出力信号波形をそれぞれ示す。図４（Ｃ）は磁気センサ８Ｃからの出力信号波形である。これらのパルス信号により回転輪２の回転数、回転方向、および原点位置を検出することができる。すなわち、磁気センサ８Ａ，８Ｂのいずれかの出力信号により回転数を検出することができる。また、磁気センサ８Ａの出力信号と磁気センサ８Ｂの出力信号の位相差から回転方向を検出することができる。さらに、磁気センサ８Ｃの出力信号から原点位置を検出することができる。
【００１９】
回転輪２における上記磁気エンコーダ７が設置される側の端面には、図５に示すように、磁気エンコーダ７の原点位置である第２の被検出部７Ｂの厚肉部分７Ｂａと円周方向位置が一致する原点位置表示マーク１５が刻印として設けられている。また、静止輪３における上記磁気センサ８Ａ〜８Ｃが設置される側の端面には、磁気エンコーダ７における第２の被検出部７Ｂを検出する磁気センサ８Ｃの円周方向の取付位置を示すセンサ取付位置表示マーク１６が刻印として設けられている。軸受１の組立時には、回転輪２の上記原点位置表示マーク１５に上記第２の被検出部７Ｂの厚肉部分７Ｂａが一致するように、磁気エンコーダ７が回転輪２に固定される。また、静止輪３の上記センサ取付位置表示マーク１６に上記磁気センサ８Ｃが一致するように、磁気センサ８Ａ，８Ｂ，８Ｃを内蔵する金属ケース１４が静止輪３に固定される。
【００２０】
このように、回転輪２および静止輪３に原点位置表示マーク１５およびセンサ取付位置表示マーク１６を設けることにより、この回転検出機能付き軸受１を回転軸およびハウジングに組み込む際に、磁気エンコーダ７の原点位置および原点位置検出用の磁気センサ８Ｃの位置を容易に確認できるので、軸受１の組込みを容易に行うことができる。
【００２１】
なお、上記原点位置表示マーク１５およびセンサ取付位置表示マーク１６は、刻印によるものに限らず、回転輪２や静止輪３の円周上の１箇所に設けられたキー溝など外見で識別できるものをこれらのマークとして利用してもよい。また、上記原点位置表示マーク１５およびセンサ取付位置表示マーク１６は、回転輪２や静止輪３に設ける場合に限らず、原点位置表示マーク１５は例えば磁気エンコーダ７のバックメタル１０に設け、センサ取付位置表示マーク１６は例えば樹脂ケース１３や金属ケース１４に設けても良い。
【００２２】
この実施形態の回転検出機能付き軸受１によると、回転数検出だけでなく、原点検出も可能でかつ回転方向も検出できる回転センサ内蔵の軸受でありながら、回転数検出センサと原点検出センサを個別に設置する必要がない。そのため、組立が簡単で、簡素でコンパクトな構造になる。
【００２３】
図６は、この発明の他の実施形態を示す断面図である。この実施形態にかかる回転検出機能付き軸受１は、図１〜図５に示した第１の実施形態において、回転センサ６を構成する磁気エンコーダ７をスラスト型としたものである。すなわち、磁気エンコーダ７は、断面Ｌ字状とされて内輪２の外径面に固定される環状のシール板２０のフランジ状の立板部２０ａに設けられている。磁気エンコーダ７は、互いに同心のリング状の第１の被検出部７Ａおよび第２の被検出部７Ｂを有し、第１の被検出部７Ａは上記シール板２０における立板部２０ａの外周側に設けられ、第２の被検出部７Ｂは第１の被検出部７Ａの内周側に設けられる。図７に示すように、第１の被検出部７Ａは、円周方向の各部の厚さが一定で、円周方向に並ぶ複数の磁極Ｎ，Ｓの形成された永久磁石とされている。第２の被検出部７Ｂは、第１の被検出部７Ｂと繋がっていて、円周上の１箇所のみ第１の被検出部７Ａと厚さが同一で、かつ磁極（ここではＮ）を有する厚肉部分７Ｂａとされ、他の部分が上記厚肉部分７Ｂａよりも薄肉部分７Ｂａとされている。
【００２４】
前記磁気エンコーダ７の両被検出部７Ａ，７Ｂを検出する磁気センサ８Ａ〜８Ｃは、磁気エンコーダ７と軸方向に向けて対向するように配置される。すなわち、例えば樹脂モールドされて断面Ｌ字状の金属ケース２４に取り付けられた磁気センサ８Ａ〜８Ｃは、金属ケース２４を静止輪３の外径面に固定することにより静止輪３側に取り付けられ、図８に示すように磁気センサ８Ａ，８Ｂが第１の被検出部７Ａに、磁気センサ８Ｃが第２の被検出部７Ｂに対向するように配置される。その他の構成および作用は第１の実施形態の場合と同様である。
【００２５】
【発明の効果】
この発明の原点付き磁気エンコーダは、リング状の第１の被検出部および第２の被検出部を有し、第１の被検出部は円周方向の各部の厚さが一定で、円周方向に並ぶ複数の磁極の形成された永久磁石であり、第２の被検出部は第１の被検出部と繋がっていて、円周上の１箇所のみ第１の被検出部と厚さが同一でかつ磁極を有する厚肉部分とされ、他の部分が薄肉部分とされているため、回転パルス信号と原点検出のための被検出部の作成および着磁が同時に行えて、製造が簡便であり、安価に製造できる。
この発明の回転検出機能付き軸受は、この発明の原点付き磁気エンコーダを備えたものであるため、回転数検出および原点検出機能を備えながら、回転数検出センサと原点検出センサを個別に設置する必要がなく、組立が簡単で、簡素でコンパクトな構造とすることができる。しかも、この発明の原点付き磁気エンコーダにおける製造簡便の効果により、高機能で安価な軸受とできる。
この発明の原点付き磁気エンコーダの製造方法は、回転パルス信号と原点検出のための被検出部の作成および着磁が同時に行えるため、製造が簡便であり、安価に製造できる。
【図面の簡単な説明】
【図１】この発明の一実施形態にかかる原点付き磁気エンコーダを内蔵した回転検出機能付き軸受の断面図である。
【図２】同磁気エンコーダの斜視図である。
【図３】（Ａ）は同磁気エンコーダの第１の被検出部と磁気センサの位置関係を示す説明図、（Ｂ）は同磁気エンコーダの第２の被検出部と磁気センサの位置関係を示す説明図、（Ｃ）は同磁気エンコーダの他の例の第２の被検出部と磁気センサの位置関係を示す説明図である。
【図４】（Ａ）は第１の磁気センサの検出信号の波形図、（Ｂ）は第２の磁気センサの検出信号の波形図、（Ｃ）は第３の磁気センサの検出信号の波形図である。
【図５】上記回転検出機能付き軸受を一端側からみた部分正面図である。
【図６】この発明の他の実施形態にかかる原点付き磁気エンコーダを内蔵した回転検出機能付き軸受の断面図である。
【図７】同磁気エンコーダの一部を示す斜視図である。
【図８】同磁気エンコーダと磁気センサとの位置関係を示す説明図である。
【図９】従来の回転検出機能付き軸受の断面図である。
【図１０】同軸受に内蔵された磁気エンコーダと磁気センサとの位置関係を示す説明図である。
【符号の説明】
１…回転検出機能付き軸受
２…回転輪
３…静止輪
４…転動体
７…原点付き磁気エンコーダ
７Ａ…第１の被検出部
７Ｂ…第２の被検出部
７Ｂａ…厚肉部分
７Ｂｂ…薄肉部分
１５…原点位置表示マーク
１６…センサ取付位置表示マーク[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a magnetic encoder with an origin that can be used for control of a motor, a joint of a robot, and the like, and a bearing with a rotation detection function incorporating the magnetic encoder.
[0002]
[Prior art]
An example of a magnetic encoder for outputting a rotation pulse signal and an origin signal once per rotation is disclosed in, for example, Japanese Patent Application Laid-Open Publication No. HEI 10-163556. As shown in FIGS. 9 and 10, in the magnetic encoder 37 of this example, in order to obtain a rotation pulse signal, a first detected portion 37 </ b> A that is multipolarly magnetized at the same pitch in the circumferential direction and a circular A magnetic pole different from that of the other portions is arranged only at one position in the circumferential direction, and is configured to include a second detected portion 37B for obtaining an origin signal. Two magnetic sensors 38A and 38B are arranged so as to face the first detected portion 37A with a phase shift of 90 ° of the magnetic pole pitch, and the rotation direction can be detected. The magnetic encoder 37 is attached to the rotating wheel 32 of the bearing 31, and the fixed wheel 33 is provided with magnetic sensors 38 </ b> A to 38 </ b> C.
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 11-194008
[Problems to be solved by the invention]
In the above-mentioned conventional magnetic encoder 37, the production and the magnetization of the pulse signals and the detection portions 37A and 37B for detecting the origin are performed separately, so that the production is complicated. Therefore, the cost increases.
[0005]
SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic encoder with an origin and a bearing with a rotation detection function, which can simultaneously produce and magnetize a rotation pulse signal and a portion to be detected for detecting the origin, which are simple and inexpensive to manufacture. It is to be.
[0006]
[Means for Solving the Problems]
A magnetic encoder with a reference point according to a first aspect of the present invention is a magnetic encoder with a reference point used for rotation detection, and has a first detection target portion and a second detection target portion which are concentric with each other in a ring shape. The first portion to be detected is a permanent magnet in which the thickness of each portion in the circumferential direction is constant and a plurality of magnetic poles arranged in the circumferential direction are formed. The second portion to be detected is connected to the first portion to be detected, and is a thick portion having the same thickness and the same magnetic pole as the first portion to be detected only at one location on the circumference. The portion is a thin portion thinner than the thick portion. The first detected portion and the second detected portion are, for example, cylindrical.
According to this configuration, the first detected portion can detect the rotation pulse signal from the magnetic poles arranged in the circumferential direction, and the second detected portion is used for detecting the origin by one magnetic pole on the circumference. . Since the first and second detected portions are connected to each other, they can be simultaneously created before magnetization. Regarding the magnetization, the second detected part has the same magnetic pole forming portion as the first detected part in the same thick part and the other part is the thin part. At the same time, even when a magnetic field for magnetizing is applied to the entire circumference, the magnetizing strength is reduced due to the wide gap in the thin portion and the small thickness of the portion to be a magnet. For this reason, the thin portion can have a negligible magnetization strength as a detection target, and can be treated as if it were not magnetized. Therefore, the magnetization of both detected parts can be performed simultaneously. As described above, the rotation pulse signal and the detection target portion for detecting the origin can be simultaneously formed and magnetized, so that the manufacturing is simple and inexpensive. In addition, since the detected portion for detecting the origin is not an independent magnet, when a core is used, it is possible to make a strong connection to the core. Further, since the rotation pulse signal and the detected part for detecting the origin are integrated, the size is reduced.
[0007]
It is preferable that the circumferential width of the thick portion in the second detection portion is substantially equal to or larger than the magnetic pole width and smaller than three times. When the width is smaller than the magnetic pole width, the magnetic pole detection signal itself becomes low. When the width exceeds three times the magnetic pole width, two or more origin signals may be generated in one rotation. Therefore, a width dimension in this range is preferable.
It is preferable that the step between the thick portion and the thin portion in the second detected portion is 0.5 mm or more. When this step is 0.5 mm or more, it is easy to prevent the magnetization intensity of the thin portion from affecting the sensor output by simultaneous magnetization of the first and second detected portions.
The first detected portion and the second detected portion may be rubber magnets. Rubber magnets have various advantages in manufacturing and performance of this type of magnetic encoder. However, in the case of rubber magnets as well, simultaneous formation and simultaneous formation of the second detected portion by forming the second portion to be detected with a thick portion and a thin portion are also possible. Magnetization can be performed easily.
[0008]
A bearing with a rotation detecting function according to the present invention includes a rotating wheel and a stationary wheel that are rotatable with each other via a rolling element, and a magnetic encoder provided on the rotating wheel. This uses a magnetic encoder with an origin having a configuration.
According to this configuration, it is possible to detect not only the rotation speed but also the origin, and the rotation detection function can also detect the rotation direction.However, there is no need to separately install the rotation speed detection sensor and the origin detection sensor. However, a simple, compact structure can be achieved. In addition, the high-performance and inexpensive bearing can be obtained by the effect of the simple manufacturing of the magnetic encoder with origin of the present invention.
[0009]
In this bearing, an origin position indicating mark whose circumferential direction coincides with the thick portion of the second detected portion of the magnetic encoder with the origin is provided on the rotating wheel, and the circle of the sensor for detecting the second detected portion is provided. A sensor mounting position display mark indicating the mounting position in the circumferential direction may be provided on the stationary wheel.
By applying each display mark in this way, even if the magnetic encoder and sensor are built in and cannot be seen from the outside, the origin position and sensor position of the magnetic encoder can be determined by looking at the origin position display mark and the sensor mounting position display mark. The bearing can be correctly assembled into a shaft or a housing, and the work of assembling the bearing can be easily and accurately performed.
The origin position display mark and the sensor mounting position display mark may be engraved marks. If it is a stamp, it can be easily applied and is not easily erased.
In the bearing with a rotation detecting function according to the present invention, a sensor for detecting the first detected portion and a sensor for detecting the second detected portion are provided in a sensor case, and the second detected portion is provided in the sensor case. A display mark indicating the circumferential position of the portion may be provided. Even when the circumferential position of the second detected portion is indicated in the sensor case, even if the second detected portion is not directly visible from the outside, the incorporation of the bearing into the housing can correct the sensor position. Easy to do.
[0010]
A method of manufacturing a magnetic encoder with an origin according to the present invention is a method of manufacturing a magnetic encoder with an origin used for rotation detection, comprising a first detected portion and a second detected portion which are concentric with each other and are in a ring shape. The thickness of each part in the circumferential direction of the first detected part is constant, and the second detected part is connected to the first detected part. A process of manufacturing an unmagnetized encoder material in which the detection portion is a thick portion having the same thickness as the other portion, and the other portion is a thin portion thinner than the thick portion; And a step of simultaneously magnetizing a plurality of magnetic poles provided in the detected portion in the circumferential direction and a magnetic pole provided in a thick portion of the second detected portion.
According to this manufacturing method, the plurality of magnetic poles N and S are magnetized in the first detected portion in the circumferential direction, and the plurality of magnetic poles N, S are also arranged in the second detected portion in the circumferential direction. S is magnetized. In the second detected portion, the magnetic pole having the same magnetic force as that of the first detected portion is magnetized in the thick portion, whereas in the thin portion, the thickness is small. Because of this, and because the gap at the time of magnetization is large, the magnetization strength is considerably smaller than that of the first detected portion, and the magnetic force is negligible as a detection target. As a result, in the second detected portion, the same result as when the magnetic pole is magnetized only in the thick portion can be obtained, and the magnetization of the first detected portion and the second detected portion can be performed simultaneously. it can.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of a bearing with a rotation detecting function which incorporates a magnetic encoder with an origin according to this embodiment. The bearing 1 with a rotation detecting function has a rotating wheel 2 and a stationary wheel 3 that are rotatable with respect to each other via a rolling element 4, and includes a magnetic encoder 7 with an origin provided on the rotating wheel 2 and a stationary wheel 3. The rotation sensor 6 is constituted by the provided three magnetic sensors 8A, 8B and 8C. The rotating wheel 2 is an inner wheel, and the stationary wheel 3 is an outer wheel. The raceway surfaces 2a, 3a of the rolling elements 4 are formed on the outer diameter surface of the rotating wheel 2 formed of the inner ring and on the inner diameter surface of the stationary wheel 3 formed of the outer ring. The rolling elements 4 are held by a holder 5. An end of the annular space between the rotating wheel 2 and the stationary wheel 3 on the side opposite to the side where the rotation sensor 6 is installed is sealed with a seal member 9.
[0012]
The magnetic encoder 7 constituting the rotation sensor 6 is of a radial type, and has an annular shape with multipolar magnetization in the circumferential direction as shown in FIG. Specifically, it has an annular back metal 10 and two detected parts 7A and 7B provided on the outer peripheral side thereof. The magnetic encoder 7 is fixed to the rotating wheel 2 via a back metal 10.
The two detected parts 7A and 7B are formed in a concentric ring shape, specifically, in a cylindrical shape. The first portion to be detected 7A is a permanent magnet in which a plurality of magnetic poles N and S alternately arranged at equal intervals in the circumferential direction are formed, with the thickness of each portion in the circumferential direction being constant. The second portion to be detected 7B is connected to the first portion to be detected 7A, and the thick portion 7Ba having the same thickness as the first to be detected portion 7A and having a magnetic pole at only one location on the circumference. The other portion is a thin portion 7Bb thinner than the thick portion 7Ba. Here, both the detected parts 7A and 7B are made of rubber magnets.
[0013]
The circumferential width W of the thick portion 7Ba in the second detected portion 7B is substantially equal to the magnetic pole width, but is set to be approximately three times the magnetic pole width as shown in FIG. Is also good. When the width W of the thick portion 7Ba in the circumferential direction is smaller than the magnetic pole width, the detection signal itself of the magnetic pole of the thick portion 7Ba becomes low, and when the width W exceeds three times the magnetic pole width, the rotating wheel Since there is a possibility that two or more origin signals are generated during one rotation of 2, the width W is preferably substantially equal to or larger than the magnetic pole width and smaller than three times. Thus, while the rotating wheel 2 makes one rotation, the second detected portion 7B surely generates one origin signal, and the origin position can be accurately detected. It is preferable that the step d between the thick portion 7Ba and the thin portion 7Bb in the second detected portion 7B is 0.5 mm or more.
[0014]
The magnetic sensors 8A, 8B, 8C are, for example, Hall elements. These magnetic sensors 8A, 8B, and 8C output incremental pulse signals in response to changes in the magnetic poles N and S of the magnetic encoder 7 facing the rotation of the rotating wheel 2. One set of two magnetic sensors 8A and 8B and another one of the magnetic sensors 8C are arranged separately in the axial direction, and the first set of the magnetic sensors 8A and 8B and the first magnetic encoder 7 opposed thereto is arranged. The first rotation sensor unit 11 is configured by the detected unit 7A. Further, a second rotation sensor unit 12 is constituted by another magnetic sensor 8C and a second detection unit 7B opposed thereto. That is, in one magnetic encoder 7, the first detected portion 7A and the second detected portion 7B are arranged in a state of being arranged in the axial direction. By arranging the two detected portions 7A and 7B in the axial direction in one magnetic encoder 7 and providing a difference in wall thickness, the two detected portions 7A and 7B can be simultaneously magnetized. As a result, the tact time for magnetization can be shortened, and the manufacturing cost can be reduced. In addition, the first detected portion 7A and the second detected portion 7B have the same phase in the repetition period of the magnetic pole arrangement, so that the magnetization operation can be performed more easily.
[0015]
In particular, the first detected portion 7A has a uniform thickness at each portion in the circumferential direction, and the second detected portion 7B is connected to the first detected portion 7A, and only one portion on the circumference is provided. Since the thick portion 7Ba has the same thickness as the first detected portion 7A and the other portion is a thin portion 7Bb thinner than the thick portion 7Ba, the two detected portions 7A and 7B are attached. Magnetization can be performed simultaneously in one step as follows.
That is, a plurality of magnetic poles N and S are arranged in a circumferential direction on a non-magnetized encoder material integrally including the first detected portion 7A and the second detected portion 7B having the above-mentioned thick structure. I do. Thereby, the plurality of magnetic poles N and S are magnetized in the first detected portion 7A in the circumferential direction, and the plurality of magnetic poles N and S are also arranged in the second detected portion 7B in the circumferential direction. Is magnetized. However, in the second detected portion 7B, the magnetic pole having the same magnetic force as that of the first detected portion 7A is magnetized in the thick portion 7Ba, whereas the other thin portion 7Bb is thin. Because of this, and because the gap at the time of magnetization is large, the magnetization strength is considerably smaller than that of the first detected portion 7A, and the magnetic force is negligible as a detection target. As a result, in the second detected portion 7B, the same result as when the magnetic pole is magnetized only in the thick portion 7Ba is obtained. In this manner, the first detected portion 7A and the second detected portion 7B can be simultaneously magnetized, so that the encoder 7 can be easily manufactured and the cost can be reduced. In addition, since the first detected portion 7A and the second detected portion 7B are not separated and independent from each other, it is possible not only to firmly join the back metal 10 but also to configure the magnetic encoder 7 compactly.
[0016]
The three magnetic sensors 8A, 8B and 8C are mounted on the stationary wheel 3 by inserting the resin into the resin case 13 and then molding the resin, and fixing the resin case 13 to the stationary wheel 3 via the metal case 14. ing.
[0017]
FIG. 3A shows the positional relationship between the first detected portion 7A and a pair of magnetic sensors 8A and 8B, and FIG. 3B shows the second detected portion 7B and one magnetic sensor 8C. The positional relationship of is shown. In the second detected portion 7B, one magnetic pole N is magnetized on the thick portion 7Ba. The phase relationship between the magnetic sensors 8A and 8B in the repetition period of the magnetic pole arrangement is a positional relationship having a phase difference of about 90 °.
FIG. 3B shows an example in which one magnetic pole N is magnetized in the thick portion 7Ba of the second detected portion 7B, but the width W of the thick portion 7Bb is slightly less than three times the magnetic pole width. In the case of, three magnetic poles (for example, S, N, and S) arranged in the circumferential direction are magnetized in the thick portion 7Ba as shown in FIG. 3C.
[0018]
FIG. 4 is a waveform diagram showing an output signal from the rotation sensor 6. FIG. 4A shows an output signal waveform from the magnetic sensor 8A, and FIG. 4B shows an output signal waveform from the magnetic sensor 8B. FIG. 4C shows an output signal waveform from the magnetic sensor 8C. With these pulse signals, the rotation speed, rotation direction, and origin position of the rotating wheel 2 can be detected. That is, the rotation speed can be detected from the output signal of either of the magnetic sensors 8A and 8B. Further, the rotation direction can be detected from the phase difference between the output signal of the magnetic sensor 8A and the output signal of the magnetic sensor 8B. Further, the origin position can be detected from the output signal of the magnetic sensor 8C.
[0019]
As shown in FIG. 5, a thick portion 7Ba of the second detected portion 7B which is an origin position of the magnetic encoder 7 and a circumferential position are provided on an end surface of the rotating wheel 2 on the side where the magnetic encoder 7 is installed. Is provided as an engraved mark. A sensor mounting indicating a circumferential mounting position of a magnetic sensor 8C for detecting the second detected portion 7B of the magnetic encoder 7 is provided on an end surface of the stationary wheel 3 on a side where the magnetic sensors 8A to 8C are installed. A position display mark 16 is provided as an engraving. At the time of assembling the bearing 1, the magnetic encoder 7 is fixed to the rotating wheel 2 such that the thick portion 7Ba of the second detected portion 7 </ b> B coincides with the reference mark 15 of the rotating wheel 2. Further, the metal case 14 containing the magnetic sensors 8A, 8B, 8C is fixed to the stationary wheel 3 so that the magnetic sensor 8C matches the sensor mounting position display mark 16 of the stationary wheel 3.
[0020]
By providing the origin position indicating mark 15 and the sensor mounting position indicating mark 16 on the rotating wheel 2 and the stationary wheel 3 in this way, when the bearing 1 with the rotation detecting function is incorporated into the rotating shaft and the housing, the magnetic encoder 7 Since the origin position and the position of the magnetic sensor 8C for detecting the origin position can be easily confirmed, the bearing 1 can be easily assembled.
[0021]
In addition, the origin position display mark 15 and the sensor mounting position display mark 16 are not limited to those by engraving, but can be identified by appearance such as a keyway provided at one place on the circumference of the rotating wheel 2 or the stationary wheel 3. May be used as these marks. Further, the origin position display mark 15 and the sensor mounting position display mark 16 are not limited to being provided on the rotating wheel 2 and the stationary wheel 3, but the origin position display mark 15 is provided on, for example, the back metal 10 of the magnetic encoder 7, and the sensor mounting The position display mark 16 may be provided on the resin case 13 or the metal case 14, for example.
[0022]
According to the bearing 1 with the rotation detecting function of this embodiment, not only the rotation speed detection but also the origin detection and the rotation sensor built-in bearing capable of detecting the rotation direction can be performed. There is no need to install it. Therefore, it is easy to assemble, and has a simple and compact structure.
[0023]
FIG. 6 is a sectional view showing another embodiment of the present invention. The bearing 1 with a rotation detecting function according to this embodiment is the same as the first embodiment shown in FIGS. 1 to 5 except that the magnetic encoder 7 constituting the rotation sensor 6 is a thrust type. That is, the magnetic encoder 7 is provided on the flange-shaped upright portion 20 a of the annular seal plate 20 having an L-shaped cross section and fixed to the outer diameter surface of the inner race 2. The magnetic encoder 7 has a first detected portion 7A and a second detected portion 7B which are concentric with each other in a ring shape. The first detected portion 7A is located on the outer peripheral side of the upright portion 20a of the seal plate 20. And the second detected portion 7B is provided on the inner peripheral side of the first detected portion 7A. As shown in FIG. 7, the first detected portion 7A is a permanent magnet in which the thickness of each portion in the circumferential direction is constant and a plurality of magnetic poles N and S arranged in the circumferential direction are formed. The second detected portion 7B is connected to the first detected portion 7B, has the same thickness as the first detected portion 7A at only one position on the circumference, and has a magnetic pole (N here). The thick portion 7Ba is provided, and the other portion is a thin portion 7Ba thinner than the thick portion 7Ba.
[0024]
The magnetic sensors 8A to 8C for detecting both the detected parts 7A and 7B of the magnetic encoder 7 are disposed so as to face the magnetic encoder 7 in the axial direction. That is, for example, the magnetic sensors 8A to 8C which are mounted on the metal case 24 having an L-shaped cross section by resin molding are mounted on the stationary wheel 3 side by fixing the metal case 24 to the outer diameter surface of the stationary wheel 3. As shown in FIG. 8, the magnetic sensors 8A and 8B are arranged so as to face the first detected portion 7A, and the magnetic sensor 8C is arranged so as to face the second detected portion 7B. Other configurations and operations are the same as those in the first embodiment.
[0025]
【The invention's effect】
A magnetic encoder with an origin according to the present invention has a ring-shaped first detected portion and a second detected portion, wherein the first detected portion has a constant thickness in each of the circumferential portions, and has a circular shape. The second detected portion is connected to the first detected portion, and the thickness of the first detected portion and the first detected portion is only one point on the circumference. It is the same thick part with magnetic poles and the other parts are thin parts, so the rotation pulse signal and the part to be detected for detecting the origin can be created and magnetized at the same time. Yes, and can be manufactured at low cost.
Since the bearing with the rotation detecting function of the present invention includes the magnetic encoder with the origin of the present invention, it is necessary to separately install the rotational speed detecting sensor and the origin detecting sensor while providing the rotational speed detecting and the origin detecting functions. And a simple and compact structure that is easy to assemble. In addition, a high-performance and inexpensive bearing can be provided by the simple manufacturing effect of the magnetic encoder with origin of the present invention.
In the method of manufacturing a magnetic encoder with an origin according to the present invention, the rotation pulse signal and the detection target portion for detecting the origin can be simultaneously formed and magnetized, so that the manufacturing is simple and inexpensive.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a bearing with a rotation detection function incorporating a magnetic encoder with an origin according to an embodiment of the present invention.
FIG. 2 is a perspective view of the magnetic encoder.
3A is an explanatory diagram showing a positional relationship between a first detected portion of the magnetic encoder and the magnetic sensor, and FIG. 3B is a diagram showing a positional relationship between a second detected portion of the magnetic encoder and the magnetic sensor; FIG. 7C is an explanatory diagram showing a positional relationship between a second detected portion and a magnetic sensor in another example of the magnetic encoder.
4A is a waveform diagram of a detection signal of a first magnetic sensor, FIG. 4B is a waveform diagram of a detection signal of a second magnetic sensor, and FIG. 4C is a waveform diagram of a detection signal of a third magnetic sensor; FIG.
FIG. 5 is a partial front view of the bearing with a rotation detecting function as viewed from one end side.
FIG. 6 is a cross-sectional view of a bearing with a rotation detection function incorporating a magnetic encoder with an origin according to another embodiment of the present invention.
FIG. 7 is a perspective view showing a part of the magnetic encoder.
FIG. 8 is an explanatory diagram showing a positional relationship between the magnetic encoder and a magnetic sensor.
FIG. 9 is a cross-sectional view of a conventional bearing with a rotation detection function.
FIG. 10 is an explanatory diagram showing a positional relationship between a magnetic encoder and a magnetic sensor incorporated in the bearing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Bearing 2 with rotation detection function 2 ... Rotating wheel 3 ... Stationary wheel 4 ... Rolling element 7 ... Magnetic encoder 7A with origin ... 1st detected part 7B ... 2nd detected part 7Ba ... Thick part 7Bb ... Thin part 15 ... Origin position display mark 16 ... Sensor mounting position display mark

Claims (10)

回転検出に用いられる原点付き磁気エンコーダであって、互いに同心のリング状の第１の被検出部および第２の被検出部を有し、第１の被検出部は円周方向の各部の厚さが一定で、円周方向に並ぶ複数の磁極の形成された永久磁石であり、第２の被検出部は第１の被検出部と繋がっていて、円周上の１箇所のみ第１の被検出部と厚さが同一でかつ磁極を有する厚肉部分とされ、他の部分が上記厚肉部分よりも薄い薄肉部分であることを特徴とする原点付き磁気エンコーダ。A magnetic encoder with an origin used for rotation detection, comprising a ring-shaped first detected part and a second detected part concentric with each other, wherein the first detected part has a thickness of each part in a circumferential direction. The second detected part is connected to the first detected part, and the first detected part is connected to the first detected part only at one position on the circumference. A magnetic encoder with an origin, characterized in that it is a thick part having the same thickness as the part to be detected and having a magnetic pole, and the other part is a thin part thinner than the thick part. 請求項１において、第１の被検出部および第２の被検出部が円筒状である原点付き磁気エンコーダ。2. The magnetic encoder with an origin according to claim 1, wherein the first detected portion and the second detected portion are cylindrical. 請求項１または請求項２において、第２の被検出部における上記厚肉部分の円周方向の幅寸法が、磁極幅と概ね同等以上でかつ３倍よりも小さい原点付き磁気エンコーダ。3. The magnetic encoder with an origin according to claim 1, wherein a circumferential width of the thick portion in the second detected portion is substantially equal to or larger than a magnetic pole width and smaller than three times. 請求項１ないし請求項３のいずれかにおいて、第２の被検出部における厚肉部分と薄肉部分との段差が０．５ｍｍ以上である原点付き磁気エンコーダ。4. The magnetic encoder with an origin according to claim 1, wherein a step between the thick portion and the thin portion in the second detected portion is 0.5 mm or more. 請求項１ないし請求項４のいずれかにおいて、第１の被検出部および第２の被検出部がゴム磁石である原点付き磁気エンコーダ。5. The magnetic encoder with an origin according to claim 1, wherein the first detected portion and the second detected portion are rubber magnets. 転動体を介して互いに回転自在な回転輪および静止輪と、上記回転輪に設けられた磁気エンコーダとを備え、この磁気エンコーダが請求項１ないし請求項５のいずれかに記載の原点付き磁気エンコーダであることを特徴とする回転検出機能付き軸受。6. A magnetic encoder with an origin according to claim 1, further comprising: a rotating wheel and a stationary wheel rotatable with respect to each other via a rolling element; and a magnetic encoder provided on the rotating wheel. A bearing with a rotation detecting function, characterized in that: 請求項６において、上記原点付き磁気エンコーダにおける第２の被検出部の厚肉部分と円周方向位置が一致する原点位置表示マークを回転輪に設け、上記第２の被検出部を検出するセンサの円周方向の取付位置を示すセンサ取付位置表示マークを静止輪に設けた回転検出機能付き軸受。7. The sensor according to claim 6, wherein an origin position indicating mark whose circumferential direction coincides with the thick portion of the second detected portion in the magnetic encoder with the origin is provided on the rotating wheel, and the second detected portion is detected. A bearing with a rotation detecting function provided with a sensor mounting position indicating mark indicating the mounting position in the circumferential direction of the stationary wheel. 請求項７において、上記原点位置表示マークおよびセンサ取付位置表示マークが刻印である回転検出機能付き軸受。The bearing with a rotation detecting function according to claim 7, wherein the origin position display mark and the sensor mounting position display mark are stamps. 請求項６において、上記第１の被検出部を検出するセンサおよび第２の被検出部を検出するセンサをセンサケース内に設け、このセンサケースに、第２の被検出部の円周方向位置を示す表示マークを設けた回転検出機能付き軸受。7. The sensor according to claim 6, wherein a sensor for detecting the first detected portion and a sensor for detecting the second detected portion are provided in a sensor case, and the sensor case has a circumferential position of the second detected portion. Bearing with a rotation detection function provided with a display mark indicating 回転検出に用いられる原点付き磁気エンコーダの製造方法であって、互いに同心のリング状の第１の被検出部および第２の被検出部を有し、第１の被検出部は円周方向の各部の厚さが一定であり、第２の被検出部は第１の被検出部と繋がっていて、円周上の１箇所のみ第１の被検出部と厚さが同一の厚肉部分とされ、他の部分が上記厚肉部分よりも薄い薄肉部分である未着磁エンコーダ素材を製造する過程と、この未着磁エンコーダ素材の第１の被検出部に円周方向に並べて設ける複数の磁極、および第２の被検出部の厚肉部分に設ける磁極を同時に着磁する過程とを含む原点付き磁気エンコーダの製造方法。A method for manufacturing a magnetic encoder with an origin used for rotation detection, comprising: a first detected portion and a second detected portion which are concentric with each other in a ring shape, wherein the first detected portion is arranged in a circumferential direction. The thickness of each part is constant, the second detected part is connected to the first detected part, and the thick part having the same thickness as the first detected part only in one place on the circumference A process of manufacturing an unmagnetized encoder material in which the other portion is a thin portion thinner than the thick portion, and a plurality of circumferentially arranged non-magnetized encoder materials provided on a first detected portion of the unmagnetized encoder material. Simultaneously magnetizing the magnetic poles and the magnetic poles provided in the thick portion of the second detected portion.
JP2002262261A 2002-09-09 2002-09-09 Magnetic encoder with original position, and bearing Pending JP2004101312A (en)

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JP2004353732A (en) * 2003-05-28 2004-12-16 Nsk Ltd Rolling bearing device with sensor
JP2006058011A (en) * 2004-08-17 2006-03-02 Nok Corp Pulsar ring for magnetic rotary encoder
EP1653079A2 (en) * 2004-10-29 2006-05-03 Ab Skf Wind turbine
JP2006226874A (en) * 2005-02-18 2006-08-31 Uchiyama Mfg Corp Magnetic encoder and tone wheel
WO2007086363A1 (en) * 2006-01-25 2007-08-02 Ntn Corporation Rolling bearing with rotation sensor
US7307414B2 (en) 2006-03-01 2007-12-11 Ntn Corporation Bearing with integrated rotation sensor
WO2008139738A1 (en) * 2007-05-16 2008-11-20 Ntn Corporation Bearing for wheel with rotational speed detector
US7508193B2 (en) * 2004-05-27 2009-03-24 Nok Corporation Encoder
JP2009287704A (en) * 2008-05-30 2009-12-10 Ntn Corp Bearing with rotation detecting device
JP2012008073A (en) * 2010-06-28 2012-01-12 Nsk Ltd Rolling bearing with sensor
DE102017115157A1 (en) * 2017-07-06 2019-01-10 Saf-Holland Gmbh flywheel
CN110631612A (en) * 2019-10-02 2019-12-31 北京金钢科技有限公司 Compact integrated multi-group separated magnetic encoder
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JP2004353732A (en) * 2003-05-28 2004-12-16 Nsk Ltd Rolling bearing device with sensor
US7508193B2 (en) * 2004-05-27 2009-03-24 Nok Corporation Encoder
JP4605352B2 (en) * 2004-08-17 2011-01-05 Ｎｏｋ株式会社 Pulsar ring for magnetic rotary encoder
JP2006058011A (en) * 2004-08-17 2006-03-02 Nok Corp Pulsar ring for magnetic rotary encoder
EP1653079A2 (en) * 2004-10-29 2006-05-03 Ab Skf Wind turbine
JP2006226874A (en) * 2005-02-18 2006-08-31 Uchiyama Mfg Corp Magnetic encoder and tone wheel
WO2007086363A1 (en) * 2006-01-25 2007-08-02 Ntn Corporation Rolling bearing with rotation sensor
US7307414B2 (en) 2006-03-01 2007-12-11 Ntn Corporation Bearing with integrated rotation sensor
WO2008139738A1 (en) * 2007-05-16 2008-11-20 Ntn Corporation Bearing for wheel with rotational speed detector
JP2009287704A (en) * 2008-05-30 2009-12-10 Ntn Corp Bearing with rotation detecting device
JP2012008073A (en) * 2010-06-28 2012-01-12 Nsk Ltd Rolling bearing with sensor
DE102017115157A1 (en) * 2017-07-06 2019-01-10 Saf-Holland Gmbh flywheel
DE102017115157B4 (en) * 2017-07-06 2020-03-12 Saf-Holland Gmbh Magnet wheel
CN110631612A (en) * 2019-10-02 2019-12-31 北京金钢科技有限公司 Compact integrated multi-group separated magnetic encoder
JP6824483B1 (en) * 2020-03-10 2021-02-03 三菱電機株式会社 Magnetic linear position detector
WO2021181535A1 (en) * 2020-03-10 2021-09-16 三菱電機株式会社 Magnetic linear position detector
US11933640B2 (en) 2020-03-10 2024-03-19 Mitsubishi Electric Corporation Magnetic linear position detector

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