JP3862927B2

JP3862927B2 - Cylinder type linear synchronous motor

Info

Publication number: JP3862927B2
Application number: JP2000098345A
Authority: JP
Inventors: 一浩牧内; 聡杉田
Original assignee: Sanyo Denki Co Ltd
Current assignee: Sanyo Denki Co Ltd
Priority date: 2000-03-31
Filing date: 2000-03-31
Publication date: 2006-12-27
Anticipated expiration: 2020-03-31
Also published as: JP2001286122A

Description

【０００１】
【発明の属する技術分野】
本発明は、可動子が直線運動をするシリンダ形リニア同期モータに関するものである。
【０００２】
【従来の技術】
現在、シリンダ形リニアモータとして実際に販売されているものとしては、シリンダ形のリニアステッピングモータ（またはリニアパルスモータ）がある。この市販されているシリンダ形のリニアステッピングモータは、内周面に直動軸の軸線方向に沿って複数の小歯が形成され且つ励磁巻線が巻装された複数の固定子コアからなる固定子と、直動軸に固定され内部に永久磁石を備えて外周面に直動軸の軸線方向に沿って複数の小歯が形成された可動部を備えた可動子とを備えている。そしてこのリニアステッピングモータでは、複数の固定子コアの励磁巻線を順次励磁することにより固定子の小歯と可動子の小歯との間に推力を発生させて直動軸を直線運動させる。リニアステッピングモータは、位置制御性能は高いものの、大きな推力を得ることができない。
【０００３】
そこで出願人は、位置制御性能は劣るが大きな推力を得ることができるシリンダ形リニア同期モータを提案した（特願平１０−１３００５１号）。
【０００４】
【発明が解決しようとする課題】
出願人が提案したシリンダ形リニア同期モータでは、予め複数の環状巻線を用意し、固定子コアの対応する複数のスロットにそれぞれ対応する環状巻線を嵌合させた構造を有している。しかしながらこのような構造では、軸線方向の長さが異なるモータ毎に固定子コアを設計して製造しなければならなかった。また固定子の組み立てが面倒であるとう問題もあった。更に、可動子と対向するスロットの開口部の幅寸法を狭くしてモータ性能を高めることができない問題もあった。本発明の目的は、軸線方向の長さを任意に設定できる構造の固定子を備えたシリンダ形リニア同期モータを提供することにある。
【０００５】
本発明の他の目的は、組み立てが容易な構造の固定子を備えたシリンダ形リニア同期モータを提供することにある。
【０００６】
本発明の更に他の目的は、環状巻線を備えてしかもスロットの可動子側の開口部を狭くすることができるシリンダ形リニア同期モータを提供することにある。
【０００７】
本発明の更に他の目的は、磁気飽和が起こらないシリンダ形リニア同期モータを提供することにある。
【０００８】
本発明の更に他の目的は、コギング推力を減少させることができるシリンダ形リニア同期モータを提供することにある。
【０００９】
【課題を解決するための手段】
本発明のシリンダ形リニア同期モータで用いる可動子は、軸線方向に往復移動する直動軸、この直動軸に固定された磁石取付部及び磁石取付部に固定され直動軸の軸線方向に並ぶ複数の永久磁石からなる１以上の永久磁石列を備えている。なお１つの永久磁石列を構成する複数の永久磁石は、物理的に組合せた複数の永久磁石であってもよいし、物理的に１つの磁性体が長手方向に交互にＮ極とＳ極とに着磁されて構成された複数の永久磁石でもよい。永久磁石列が複数列ある場合には、複数列の永久磁石列は周方向にほぼ等しい間隔をあけて配置するのが好ましい。但し、径方向の外面にＮ極またはＳ極が現れるように着磁された円環状永久磁石を用いて、永久磁石列の集合体を構成してもよい。具体的には、可動子の磁石取付体の外周部に軸線方向に所定の間隔をあけてＮ極とＳ極が交互に並ぶように円環状永久磁石を嵌合させて固定する。このような複数の円環状永久磁石を用いた場合には、複数の円環状永久磁石の固定子コアの複数の磁極部と対向する部分が、それぞれ永久磁石列を構成する複数の永久磁石となる。このような円環状永久磁石を用いると、可動子の構造が簡単になるだけでなく、永久磁石の磁石取付体への取付が容易になる。
【００１０】
また固定子は、巻線導体が環状に巻かれて形成され、軸線方向に所定の間隔をあけて配置され且つ可動子の周囲を囲むように配置された複数の環状巻線を備えている。また固定子は、可動子の永久磁石列と所定の間隙を介して対向する複数の磁極部及びこれら複数の磁極部を磁気的に連結するヨークを有し且つ隣接する２つの磁極部間に対応する環状巻線の少なくとも一部を受け入れるスロットを形成するように複数の磁極部が軸線方向に間隔をあけて配置されてなる固定子コアユニットを備えている。ここでスロットは、可動子に向かって開口する開口部と環状巻線の少なくとも一部を受け入れる巻線受け入れ部とを有している。
【００１１】
シリンダ形リニア同期モータでは、固定子の複数の環状巻線（励磁巻線）に流れる励磁電流の通電方向を変えて複数の磁極部の磁極面に現れる磁極の極性を変えることにより移動磁界を発生して、１以上の永久磁石列と複数の磁極部との間に直動軸を軸線方向に変位させる推力を発生する。励磁電流が交流電流であれば、その周波数に応じて磁極部の磁極面に現れる磁極の極性が変化することになる。多相の交流電流を複数の励磁巻線に通電すれば多相同期モータとなるため、大きな推力を得ることができる。励磁電流の極性及び大きさを固定すれば固定子と可動子との間には吸引力のみが働き、可動子の位置は固定される。
【００１２】
固定子コアユニットの磁極部を励磁する場合、回転電機の発想に従えば、磁極部の外周に巻線導体を巻回することになる。この回転電機の発想をリニア同期モータに持ち込むと、軸線方向の長さが長くなる上、巻線の巻回作業が大変になる。そこで本発明では、固定子の複数の励磁巻線として、それぞれ可動子の周囲を周方向に囲むように巻線導体を環状に巻回してなる環状巻線を用いる。そして固定子コアユニットの軸線方向に隣接する２つの磁極部間に形成されたスロットに対応する１つの環状巻線の少なくとも一部を嵌合させる構造を採用する。このようにすると１つのスロットに嵌合された励磁巻線が発生する磁束が隣接する２つの磁極部を循環するように流れて、隣接する２つの磁極部の磁極面には極性の異なる磁極が現れる。１以上の固定子コアユニットの複数のスロットに嵌合した複数の環状巻線に流す励磁電流を適当に切り替えることにより、固定子側に軸線方向の一方の方向から他方の方向に向かって（または他方の方向から一方の方向に向かって）Ｎ極とＳ極の磁界が所定の速度で移動しているのと同じ状態の移動磁界が得られる。この移動磁界は、多相同期電動機で用いる回転磁界に相当するものである。この移動磁界により、固定子コアユニットの複数の磁極部と可動子の永久磁石列との間に推力が発生して直動軸が軸線方向に移動する。固定子コアの複数の磁極部の磁極面に現れる磁極を一定にすれば、可動子と固定子との間には吸引力のみが発生して可動子は固定される。
【００１３】
本発明においては、固定子コアユニットとして、固定子コアユニットのスロットに対応するヨークの部分に軸線方向に組合せ可能な組合せ構造部を有する複数の固定子コア分割体が軸線方向に組み合わされて構成される構造のものを用いる。また、本発明では、固定子コア分割体は導磁性材料により一体に成形されており、直動軸と同心的に配置される環状のヨーク構成部分と環状の磁極部とを有する構造を有している。そして、環状の磁極部は、永久磁石列と対向する磁極面を有する環状の磁極面形成部と磁極面形成部と環状のヨーク構成部分とを連結する環状の連結部とを有しており、環状の連結部は、磁極面形成部からヨーク構成部分に向かうに従って、磁路断面積がほぼ一定になるように連続的に厚みが薄くなる構造を有している。ここで「スロットに対応するヨークの部分」とは、その部分に設けた組合せ構造部で２つの固定子コア分割体を分割すると、スロットが２つに分かれてしまう（または１つのスロットが形状を維持できなくなる部分）であり、スロットが完全に２分割される部分に限られるものではない。
【００１４】
ここで軸線方向に組合せ可能な組合せ構造部の構造として、凹凸嵌合構造により組み合される構造や、また２つの固定子コア分割体のヨーク構成部分に対向する凹部またはスリットをそれぞれ形成し、対向する２つの凹部またはスリットの双方に共通の嵌合部材を嵌合させて組み合わされる構造等、公知の組合せ構造を用いることができる。
【００１５】
本発明のように固定子コアユニットを、複数の固定子コア分割体を軸線方向に組み合わせて構成する構造にすると、固定子コアユニットの長さを組み合わされる固定子コア分割体の数や形状によって任意に定めることができる。したがって励磁巻線の相数を増加させたり、永久磁石列の長さを長くして大きな推力を得る場合にも、新規に固定子コアユニットを設計製造する必要がない。また複数の固定子コア分割体を組み合わせる過程で、環状巻線の少なくとも一部をスロット間に配置することができるので、固定子コアユニットと環状巻線の組合せが容易になり、結果として固定子の製造組み立てが容易になる。またこの構造を採用すると、スロット内に巻線の少なくとも一部を押し込む場合と比べて、スロット内に収納できる巻線の占積率を高めることができる。
【００１６】
特に本発明では、固定子コア分割体は導磁性材料により一体に成形されており、直動軸と同心的に配置される環状のヨーク構成部分と環状の磁極部とを有する構造を有しているので、複数の固定子コア分割体を組み合わせるだけで、簡単に固定子コアユニットを形成でき、固定子の製造組み立てが容易になる。また、環状の磁極部は、磁極面を有する環状の磁極面形成部と、磁極面形成部とヨーク構成部分とを連結する環状の連結部とを有しており、環状の連結部は、磁極面形成部からヨーク構成部分に向かうに従って、磁路断面積がほぼ一定になるように連続的に厚みが薄くなる構造を有しているので、磁気飽和が起こらない上、スロットの占有率を高められる。
【００１７】
磁極面形成部からヨーク構成部分に向かうに従って、磁路断面積をほぼ一定にする具体的な方法としては、環状の連結部を円板状に形成し、環状の連結部の径方向内側部の半径寸法をＲ１とし、環状の連結部の径方向内側部の厚み寸法をＴ１とし、環状の連結部の径方向外側部の半径寸法をＲ２とし、環状の連結部の径方向外側部の厚み寸法をＴ２としたときに、Ｔ１×Ｒ１＝Ｔ２×Ｒ２の条件を満たすように環状の連結部の厚みを連続的に薄くすればよい。
【００１８】
磁極面形成部の厚み寸法Ｔ３を、コギング推力を減少させるように厚み寸法Ｔ１よりも大きく設定すれば、コギング推力を減少できる上、磁極部の磁極面の面積を大きくして、より大きな推力を有するシリンダ形リニア同期モータを得ることができる。また、固定子コア分割体のうち軸線方向の両端に位置する２つの固定子コア分割体の間に位置する固定子コア分割体は、それぞれ同じ形状を有しているので、軸線方向の両端に位置する２つの固定子コア分割体の形状を変えるだけで、コギングを低減できる。
【００１９】
このように磁極面形成部の厚み寸法Ｔ３を厚み寸法Ｔ１よりも大きく設定してコギング推力の減少を図るには、固定子コアユニットの軸線方向両側に位置する一対の固定子コア分割体の間に位置する複数の固定子コア分割体の磁極面形成部の厚み寸法を一定にし、固定子コアユニットの軸線方向両側に位置する一対の固定子コア分割体の磁極面形成部の厚み寸法を、固定子コアユニットの軸線方向両側に位置する一対の固定子コア分割体の磁極面形成部の磁極面の軸線方向の内側角部間の寸法Ａと固定子コアユニットの軸線方向両側に位置する一対の固定子コア分割体の磁極面形成部の磁極面の軸線方向の外側角部間の寸法Ｂとの関係が、コギングを低減する関係になるように定めればよい。
【００２０】
【発明の実施の形態】
以下、本発明の実施の形態の一例を詳細に説明する。図１は、本発明の実施の形態を説明するために用いる本発明の前提となる出願人が先に提案したシリンダ形リニア三相同期モータ１の一部破断断面図であり、図２は図１の半部横断面図である。このシリンダ形リニア三相同期モータ１のケース３は、非磁性材料（例えばアルミニューム）製のシリンダ形のフレーム５とアルミニューム製の一対のエンドブラケット７及び９とから構成されている。フレーム５は、内部に円筒状の空洞５ａを有しており、またその両端開口部の内側にエンドブラケット７及び９が嵌合される環状の段部５ｂ，５ｂを有している。エンドブラケット７及び９の中央部の開口部７ａ及び９ａには、ボールスプラインからなるリニア軸受１１及び１３が嵌合されている。リニア軸受１１及び１３は、エンドブラケット７及び９に対して４本の捩子１５で固定されている。一対のエンドブラケット７及び９のフレーム５の段部５ｂ，５ｂに嵌合される環状突出部７ｂ及び９ｂの外周部には、径方向外側に向かって開口する環状の溝７ｃ及び９ｃが形成されており、この溝７ｃ及び９ｃ内にはシール用のオーリング１７及び１９が嵌合されている。図２に示されるようにエンドブラケット７及び９には、輪郭形状がほぼ四角形をなすフランジ部７ｄ及び９ｄが一体に設けられており、このフランジ部の四隅には、取付用のボルトを挿入する孔２１及び２３がそれぞれ形成されている。なおエンドブラケット７及び９は、フレーム５に対して捩子２５により固定されている。
【００２１】
一対のリニア軸受１１及び１３には、直線往復運動可能に鉄製の直動軸２７が支持されている。図１に示した状態は、直動軸２７の負荷が接続される出力軸部２７ａが最も外側に突出した状態である。ケース３の内部に位置する直動軸２７の部分には、磁性材料である鉄製の磁石取付体２９が直動軸２７と同心になるように固定されている。磁石取付体２９は、基本的には円筒形状を成しており、その内部には直動軸２７の外周に嵌合される嵌合孔２９ａと、この嵌合孔２９ａの両側に位置して嵌合孔２９ａよりも径寸法の大きい第１及び第２の大径孔２９ｂ及び２９ｃが形成されている。第１の大径孔２９ｂは、リニア軸受１１の内側端部の外周面と接触しない径寸法を有しており、また第２の大径孔２９ｃもリニア軸受１３の外周面と接触しない径寸法を有している。磁石取付体２９の第１の大径孔２９ｂが形成されている部分（直動軸２７の出力軸部２７ａ側の端部）の外周には、後に説明する位置検出センサの被検出部５１として用いられるリニアスケールが取付けられる段部２９ｄが形成されている。また第２の大径孔２９ｃが形成される部分の外周部が磁石取付部３０を構成している。磁石取付部３０は、直動軸２７の軸線方向に延びるほぼ円筒形状を有してり、その外周には８個の円環状永久磁石３１ａ〜３１ｈが嵌合されている。隣接する２つの円環状永久磁石の間及び円環状永久磁石３１ｈの軸線方向外側には非磁性材料からなり一部が切断されたほぼ環状またはＣ字状のストッパ部材３３…が嵌合されている。磁石取付部３０の外周部には、ストッパ部材３３…が嵌合される嵌合溝が形成されている。なお円環状永久磁石３１ａ〜３１ｈは接着剤を介して磁石取付部３０に固定してもよいし、円環状永久磁石３１ａ〜３１ｈの全体を合成樹脂によりモールドしてもよい。更に円環状永久磁石３１ａ〜３１ｈが嵌合された磁石取付部３０の外側に熱収縮チューブを被せた後、熱収縮チューブを加熱して熱収縮させて、円環状永久磁石３１ａ〜３１ｈを全体的に包み込むようにしてもよい。円環状永久磁石３１ａ，３１ｃ，３１ｅ及び３１ｇは、径方向の外面にＮ極が現れるように着磁されており、円環状永久磁石３１ｂ，３１ｄ，３１ｆ及び３１ｈは、径方向の外面にＳ極が現れるように着磁されている。その結果、直動軸２７の軸線方向にＮ極とＳ極とが交互に並ぶ永久磁石の列が形成されることになる。なお後述する６個の固定子コアユニット３５…の７個の磁極部と対向する各円環状永久磁石の部分が、それぞれ本発明における周方向に所定の間隔を明けて配置された複数の永久磁石列を構成する複数の永久磁石を構成する。この例では、直動軸２７と、磁石取付体２９と円環状永久磁石３１ａ〜３１ｈによって可動子３２が構成されている。
【００２２】
なお磁石取付体２９の直動軸２７への固定の態様は任意であるが、この例では直動軸２７の２か所に周方向に４つずつ設けた嵌合孔にピン３４を嵌合して磁石取付体２９を直動軸２７に対して固定している。
【００２３】
フレーム５の内周部には、固定子コアユニット３５…が固定されている。固定子コアユニット３５…は、フレーム５の内周側に固定された基部すなわちヨーク３５ａ及び直動軸２７の径方向において磁極面３５ｂ…が円環状永久磁石３１ａ〜３１ｈによって形成される永久磁石列と対向し且つ直動軸２７の軸線方向に所定の間隔をあけて配置された７つの磁極部３５ｃ…を有している。
【００２４】
固定子コアユニット３５は、７つの固定子コア分割体３６ａ〜３６ｇが軸線方向に組み合わされて構成されている。固定子コア分割体３６ａ〜３６ｇは、固定子コアユニット３５のスロットの中央部に対応するヨーク３５ａの部分に軸線方向に分離可能な組合せ構造部を有している。固定子コア分割体３６ａ〜３６ｇは、それぞれ１つの磁極部３５ｃとヨーク３５ａの一部を構成するヨーク構成部分とを有している。隣接する２つの固定子コア分割体の組合せ面（当接面）には、組合せ構造部を構成する組合せ可能な凹部と凸部とがそれぞれ形成されており、隣接する２つの固定子コア分割体はその組合せ構造部により相互に連結されている。固定子コア分割体３６ａ〜３６ｇのうち軸線方向の両端に位置する２つの固定子コア分割体３６ａ及び３６ｇはそれぞれ同じ形状を有しており、また２つの固定子コア分割体３６ａ及び３６ｇの間に位置する５つの固定子コア分割体３６ｂ〜３６ｅもそれぞれ同じ形状を有している。
【００２５】
各固定子コアユニット３５の隣接する２つの磁極部３５ｃ間に形成される６個のスロットには、巻線導体を環状に巻回してなる励磁巻線を構成する環状巻線３９ａ〜３９ｆの一部がそれぞれ嵌合されている。なお図１の例では、各環状巻線３９ａ〜３９ｆは、合成樹脂製のボビン４１に巻線導体が巻回されて構成されており、ボビン４１の一部と一緒に環状巻線が各スロットに嵌合されている。
【００２６】
環状巻線３９ａ〜３９ｆは、固定子コア分割体３６ａ〜３６ｇを組み合わせて６個の固定子コアユニット３５…を一緒に組み立てる際に、２つの固定子コア分割体の間に順次挟み込まれる。具体的には、６個の固定子コアユニット３５…を構成するための７個の固定子コア分割体３６ａを組立治具の上に所定の間隔をあけて環状に並べ、その上に環状巻線３９ａを配置する。次に、環状巻線３９ａを間に挟むようにして６個の固定子コア分割体３６ｂを６個の固定子コア分割体３６ａの上に組み合わせる。以後、環状巻線３９ｂ〜３９ｆと各６個の固定子コア分割体３６ｃ〜３６ｇを同様にして順次重ねて同時に６個の固定子コアユニット３５…を組み立ててる。そして最後に各固定子コア分割体３６ａ〜３６ｇの結合部にレーザを照射して各固定子コア分割体３６ａ〜３６ｇを一体化する。
【００２７】
この例では固定子コアユニット３５…、環状巻線３９ａ〜３９ｆ及びストッパ部材３７を絶縁モールド材料によりモールドしてモールド部４５を形成する。なお図１においては、モールド部４５を破線で示してある。ストッパ面５ｄとストッパ部材３７は、固定子コアユニット３５…に働く軸線方向への反力を受けて、固定子コアユニット３５…が軸線方向に変位するのを阻止する機能を果たす。この機能があるために、モールド部４５に力が加わってモールド部４５にクラック等が入るのを防止できる。なおこの例では、固定子コアユニット３５…と環状巻線３９ａ〜３９ｆとにより固定子４７が構成されている。
【００２８】
リニアステッピングモータと異なって、リニア同期モータは、環状巻線３９ａ〜３９ｆに流れる励磁電流を切り替えるために、可動子３２と固定子４７との軸線方向における位置関係を検出する位置検出センサを必要とする。ケースの外部に突出する直動軸２７の変位を検出するように位置検出センサを設けることも考えられるが、このようにすると既存のモータと同様の感覚で取扱うことができず不便である。またこのようにすると温度変化による各部材の熱膨脹による検出誤差が大きくなって位置制御精度が悪くなる問題も生じる。そこでこの例では、図１に示すように可動子３２と固定子４７との軸線方向における位置関係を検出する位置検出センサ４９をフレーム５の内部に配置している。位置検出センサ４９は、可動子３２に取付けられた光学的にまたは磁気的に検出可能な被検出部５１と、フレーム５の内周部に固定されて被検出部５１の位置または移動量を光学的にまたは磁気的に検出する検出部５３とから構成できる。光学的に位置を検出する位置検出センサでは、被検出部５１として所定の反射パターンを備えたリニアスケールを用いる。そして発光部と受光部とを備えた検出部５３から被検出部５１に光を照射して反射してきた光に含まれる情報に基づいて位置を検出する。この例では、可動子３２の磁石取付体２９とフレーム５は熱膨脹係数が異なる材料によって形成されている。そこで被検出部５１を直動軸２７の負荷が接続される出力軸部２７ａに近い位置に配置し、検出部５３も出力軸部２７ａに近い位置に配置してある。直動軸２７の出力軸部２７ａを通して負荷側から伝達される熱が直動軸２７を通して、モータ１のケース３の内部に伝わると、直動軸２７、磁石取付体２９及びフレーム５がそれぞれ熱膨脹を起こす。もし直動軸２７の出力軸部２７ａと反対側の非出力軸部２７ｂ側に位置検出センサを配置すると、出力軸部２７ａ側から非出力軸部側２７ｂに位置する各部の膨脹が累積して被検出部及び検出部の取付位置の変化として現れる。これに対してこの例のように位置検出センサ４９の被検出部５１及び検出部５３を直動軸２７の出力軸部側に近い位置に配置すると、被検出部５１及び検出部５３の取付位置を変化させる熱膨脹の累積値がわずかであるため、位置検出センサ４９の検出精度が高くなり、その分リニア同期モータの位置決め精度が高くなる。
【００２９】
図１の例では、直動軸２７の負荷が接続されない非出力軸部２７ｂ側の端部を支持するリニア軸受１３が取付けられる側のエンドブラケット９には、エンドブラケット９から突出する直動軸２７の非出力軸部２７ｂ側の端部を覆う金属製または合成樹脂製のカバー部材５５が取付けられている。カバー部材５５を設けると、直動軸２７の非出力軸部２７ｂとリニア軸受部１３を保護できる。特にこの例ではカバー部材５５として防水性を有する構造のものを用いている。具体的には、カバー部材５５のフランジ部５５ａに、エンドブラケット９の外面に向かう方向に開口する環状の嵌合溝が形成してあり、この嵌合溝にシール用のオーリング５７が圧縮状態で嵌合されている。なおカバー部材５５は、フランジ部５５ａに設けた図示しない複数の貫通孔に捩子を挿入してエンドブラケット９に対して捩子止めされている。このような構造にすると、直動軸２７の非出力軸部２７ｂ側からモータの内部に水分が入り込むのを阻止できる。このような機能は、特に直動軸２７の非出力軸部側２７ｂが上側に位置するようにして直動軸２７を上下方向に変位させる姿勢でこのリニア三相同期モータ１を用いる場合に効果を発揮する。
【００３０】
シリンダ形リニア同期モータでは、固定子４７の環状巻線３９ａ〜３９ｆに流れる励磁電流の通電方向を変えて各固定子コアユニット３５の磁極部３５ｃ…の磁極面３５ｂ…に現れる磁極の極性を変えることにより移動磁界を発生し、可動子３２の永久磁石列と固定子４７の磁極部３５ｃ…との間に直動軸２７を軸線方向に変位させる推力を発生する。この例では励磁電流として正弦波の三相交流を用いる。三相交流の周波数に応じて磁極部３５ｃ…の磁極面３５ｂ…に現れる磁極の極性が変化する。多相の交流電流を環状巻線に通電すれば多相同期モータとなるため、大きな推力を得ることができるのである。励磁電流を変化させなければ（極性及び大きさを固定すれば）固定子４７と可動子３２との間には吸引力のみが働き、可動子３２の位置は固定されることになる。
【００３１】
この例の環状巻線３９ａ〜３９ｆの励磁態様について、図３を及び図４を用いて簡単に説明する。まずこの例では、電気角で１２０度ずつ位相がずれた３相の励磁電流Ｕ，Ｖ及びＷを用いる。そこで６個の固定子コアユニット３５…の隣接する２個のスロットに嵌合される２個の環状巻線３９ａ及び３９ｂにはＵ相の励磁電流を流し、その次に隣接する２個のスロットに嵌合される２個の環状巻線３９ｃ及び３９ｄにはＶ相の励磁電流を流し、その次に隣接する２個のスロットに嵌合される２個の環状巻線３９ｅ及び３９ｆにはＷ相の励磁電流を流す。そして６個の固定子コアユニット３５…のそれぞれの軸線方向に隣接する２つの磁極部３５ｃ…に現れる極性が異極性になるように６個の環状巻線３９ａ〜３９ｆを結線する。この例では、図３に示した磁束の流れを生じさせるために、Ｕ相の励磁電流を流す環状巻線３９ａ及び３９ｂにはそれぞれ逆方向にＵ相の励磁電流が流れるように引出し線を結線して、結線した引出し線にＵ相の給電線を接続する。なお図３に示した記号は電流の流れる方向を示している。Ｖ相の励磁電流を流す環状巻線３９ｃ及び３９ｄも，それぞれ逆方向にＶ相の励磁電流が流れるように引出し線を結線して、結線した引出し線にＶ相の給電線を接続する。同様にして、Ｗ相の励磁電流を流す環状巻線３９ｅ及び３９ｆも，それぞれ逆方向にＷ相の励磁電流が流れるように引出し線を結線して、結線した引出し線にＷ相の給電線を接続する。
【００３２】
このように結線して、位置検出センサ４９の出力に基づいて、各環状巻線に流れる励磁電流を切り替えることにより、見掛け上軸線方向に移動する移動磁界を発生させると、同期電動機の原理と同様の動作原理で、可動子３２が軸線方向に移動する。励磁電流の切り替えを停止すれば、可動子３２と固定子４７との間には吸引力のみが働き可動子３２は停止する。
【００３３】
この例で用いた励磁態様を一般的に説明すると次のようになる。まず複数の環状巻線に位相の異なるｐ相（但しｐは２以上の正の整数）の励磁電流を流して移動磁界を得る場合には、ｍ個（但しｍは２以上の正の整数）の固定子コアユニットを用いるときには、ｍ個の固定子コアユニットを周方向にほぼ等しい間隔をあけて配置する。また複数の環状巻線として、ｐ×ｑ個（但しｑは１以上の正の整数）の環状巻線を用意する。１つの固定子コアユニットにｎ個の磁極部を設けるとすると、この場合ｎはｎ＝ｐ×ｑ＋１の関係になる。そしてｍ個の固定子コアユニットの軸線方向に隣接する２つの磁極部間にそれぞれ形成されるｎ−１個のスロットに、それぞれ対応する１つの環状巻線の一部を嵌合させる。このようにするとｍ個の固定子コアユニットのｎ個の磁極部から、完全に同期した移動磁界を発生せることができる。スロットに環状巻線を嵌合させるだけでよいため、スロットの軸線方向の寸法（隣接する２つの磁極部間の間隔）が狭くなっても、固定子を簡単に構成することができる。そして多相の励磁電流を用いて推力を高める場合には、ｍ個の固定子コアユニットの軸線方向に連続して並ぶｑ個のスロットに嵌合されたｑ個の環状巻線に同じ相の励磁電流を流す。そしてこのときでもｍ個の固定子コアユニットのそれぞれの軸線方向に隣接する２つの磁極部に現れる極性が異極性になるようにｐ×ｑ個の環状巻線を結線する。このようにすると、多相化した場合でも配線が複雑にならない。推力を増減する場合には、同じ相の励磁電流が流れる環状巻線の数を増減すればよい。
【００３４】
図５は、本発明の実施の形態のシリンダ型リニア同期モータに用いる固定子コアユニット１３５の半部断面図である。この固定子コアユニット１３５は、１０個の固定子コア分割体１３６ａ〜１３６ｊが直動軸２７の軸線方向に組み合わされて構成されている。固定子コア分割体１３６ａ〜１３６ｊは、固定子コアユニット１３５のスロットの中央部に対応するヨーク１３５ａの部分に軸線方向に分離可能な組合せ構造部を有している。具体的には、この組合せ構造部は、後述するヨーク構成部分１３６ｂ1の突出部１３６ｂ4，１３６ｂ5の凹部と凸部とにより構成されており、隣接する２つの固定子コア分割体はその組合せ構造部により相互に連結されている。固定子コア分割体１３６ａ〜１３６ｊのうち軸線方向の両端に位置する２つの固定子コア分割体１３６ａ及び１３６ｊの間に位置する８つの固定子コア分割体１３６ｂ〜１３６ｉは、それぞれ同じ形状を有している。図６（Ａ）及び（Ｂ）は、これらの８つの固定子コア分割体１３６ｂ〜１３６ｉの一つ（１３６ｂ）の平面図及び一部切り欠き側面図である。固定子コア分割体１３６ｂは、導磁性材料により一体に成形され、直動軸２７と同心的に配置される環状のヨーク構成部分１３６ｂ1と環状の磁極部１３６ｂ2とを有している。ヨーク構成部分１３６ｂ1は、環状の構成部分本体１３６ｂ3と、構成部分本体１３６ｂ3から直動軸２７の軸方向両側に突出する２つの環状の突出部１３６ｂ4，１３６ｂ5とを有している。突出部１３６ｂ4，１３６ｂ5は、隣接する固定子コア分割体の向かい合う突出部と分離可能な凹凸の組合せ構造部を構成している。磁極部１３６ｂ2は、可動子３２の永久磁石列と対向する磁極面１３６ｂ6を有する環状の磁極面形成部１３６ｂ7と、磁極面形成部１３６ｂ7とヨーク構成部分１３６ｂ1とを連結する円板状をなす環状の連結部１３６ｂ8とを有している。ヨーク構成部分１３６ｂ1及び連結部１３６ｂ8には、環状巻線のリード線を引き出すための切り欠き凹部ＬＨが形成され、連結部１３６ｂ8及び磁極面形成部１３６ｂ7には、切り欠き凹部ＬＨと連通して環状巻線のリード線を入れる溝ＬＲが形成されている。連結部１３６ｂ8は、磁極面形成部１３６ｂ7からヨーク構成部分１３６ｂ1に向かうに従って、磁路断面積がほぼ一定になるように連続的に厚みが薄くなる構造を有している。具体的には、連結部１３６ｂ8の径方向内側部の半径寸法をＲ１とし、連結部１３６ｂ8の径方向内側部の厚み寸法をＴ１とし、連結部１３６ｂ8の径方向外側部の半径寸法をＲ２とし、連結部１３６ｂ8の径方向外側部の厚み寸法をＴ２としたときに、Ｔ１×Ｒ１＝Ｔ２×Ｒ２の条件を満たすように連結部１３６ｂ8の厚みは、連続的に薄くなっている。本例のように、磁極面形成部１３６ｂ7からヨーク構成部分１３６ｂ1に向かうに従って、磁路断面積がほぼ一定になるように連結部１３６ｂ8の厚みを連続的に薄くすると磁気飽和が起こらない。また、磁極面形成部１３６ｂ7の厚み寸法Ｔ３は、連結部１３６ｂ8の径方向内側端部の厚み寸法Ｔ１よりも大きく設定されている。即ち、磁極面形成部１３６ｂ7は、環状の形成部本体１３６ｂ9と、形成部本体１３６ｂ9から直動軸２７の軸方向に突出する２つの環状の肩部１３６ｂ10，１３６ｂ11とを有することになる。本例のように、磁極面形成部１３６ｂ7の厚み寸法Ｔ３を連結部１３６ｂ8の径方向内側端部の厚み寸法Ｔ１よりも大きく設定すると、コギング推力を減少できる上、磁極面１３６ｂ6の面積を大きくして、より大きな推力を有するシリンダ形リニア同期モータを得ることができる。
【００３５】
固定子コア分割体１３６ａ〜１３６ｊのうち直動軸２７の軸線方向の両端に位置する固定子コア分割体１３６ａ及び１３６ｊも、固定子コア分割体１３６ｂと同様に導磁性材料により一体に成形され、図５に示すように、直動軸２７と同心的に配置される環状のヨーク構成部分１３６ａ1，１３６ｊ1と環状の磁極部１３６ａ2，１３６ｊ2とをそれぞれ有している。図面に向かって左端部の固定子コア分割体１３６ａのヨーク構成部分１３６ａ1は、環状の構成部分本体１３６ａ3と、構成部分本体１３６ａ3から隣接する固定子コア分割体１３６ｂ側に突出する１つの環状の突出部１３６ａ5とを有している。図面に向かって右端部の固定子コア分割体１３６ｊのヨーク構成部分１３６ｊ1は、環状の構成部分本体１３６ｊ3と、構成部分本体１３６ｊ3から隣接する固定子コア分割体１３６ｉ側に突出する１つの環状の突出部１３６ｊ4とを有している。磁極部１３６ａ2，１３６ｊ2は、可動子３２の永久磁石列と対向する磁極面１３６ａ6，１３６ｊ6を有する環状の磁極面形成部１３６ａ7，１３６ｊ7と、磁極面形成部１３６ａ7，１３６ｊ7とヨーク構成部分１３６ａ1，１３６ｊ1とを連結する円板状をなす環状の連結部１３６ａ8，１３６ｊ8とをそれぞれ有している。なお、固定子コア分割体１３６ａ〜１３６ｊは、環状巻線のリード線を引き出すために径方向に延びる図示しない貫通溝が形成されているため、完全な環状にはなっていない。しかしながらこのような場合も本出願においては、環状に含まれるものとする。連結部１３６ａ8，１３６ｊ8は、磁極面形成部１３６ａ7，１３６ｊ7からヨーク構成部分１３６ａ1，１３６ｊ1に向かうに従って、磁路断面積がほぼ一定になるようにそれぞれ連続的に厚みが薄くなる構造を有している。図面に向かって左端部の固定子コア分割体１３６ａの磁極面形成部１３６ａ7は、環状の形成部本体１３６ａ9と、形成部本体１３６ａ9から隣接する固定子コア分割体１３６ｂ側に突出する１つの環状の肩部１３６ａ11を有している。図面に向かって右端部の固定子コア分割体１３６ｊの磁極面形成部１３６ｊ7は、環状の形成部本体１３６ｊ9と、形成部本体１３６ｊ9から隣接する固定子コア分割体１３６ｉ側に突出する１つの環状の肩部１３６ｊ10を有している。また、磁極面形成部１３６ａ7，１３６ｊ7の厚み寸法は、磁極面形成部１３６ａ7，１３６ｊ7の磁極面１３６ａ6，１３６ｊ6の軸線方向の内側角部間の寸法（肩部１３６ａ11と肩部１３６ｊ10との間の寸法）Ａと、磁極面形成部１３６ａ7，１３６ｊ7の磁極面１３６ａ6，１３６ｊ6の軸線方向の外側角部間の寸法Ｂとの関係が、コギングを低減する関係になるように定められている。本例では、内側角部間の寸法Ａは９３．４ｍｍに設定されており、外側角部間の寸法Ｂは１０１．４ｍｍに設定されている。また、磁極面形成部１３６ａ7，１３６ｊ7の軸線方向の両端部外側の部分には、磁極面１３６ａ6，１３６ｊ6から４５°の角度で傾斜するテーパ部が形成されている。
【００３６】
なお上記の例で説明した環状巻線の励磁態様または方法は一例であって、本発明を実施する場合の環状巻線の励磁方法は移動磁界を発生できるものであれば任意である。
【００３７】
【発明の効果】
本発明によれば、固定子コアユニットを複数の固定子コア分割体を軸線方向に組み合わせて構成するため、固定子コアユニットの長さを組み合わされる固定子コア分割体の数や形状によって任意に定めることができる利点がある。そのため、励磁巻線の相数を増加させたり、永久磁石列の長さを長くして大きな推力を得る場合にも、設計が容易である。また複数の固定子コア分割体を組み合わせる過程で、環状巻線の少なくとも一部をスロット間に嵌合するように配置することができるので、固定子コアユニットと環状巻線の組合せが容易になり、結果として固定子の製造組み立てが容易になる利点がある。またこの構造を採用すると、スロット内に巻線の少なくとも一部を押し込む場合と比べて、スロット内に収納できる巻線の占積率を高めることができる利点がある。
【００３８】
特に本発明では、固定子コア分割体は導磁性材料により一体に成形されており、直動軸と同心的に配置される環状のヨーク構成部分と環状の磁極部とを有する構造を有しているので、複数の固定子コア分割体を組み合わせるだけで、簡単に固定子コアユニットを形成でき、固定子の製造組み立てが容易になる。また、環状の連結部が、磁極面形成部からヨーク構成部分に向かうに従って、磁路断面積がほぼ一定になるように連続的に厚みが薄くなる構造を有しているので、磁気飽和が起こらない上、スロットの占有率を高められる。また、磁極面形成部の厚み寸法Ｔ３を、コギング推力を減少させるように厚み寸法Ｔ１よりも大きく設定するので、コギング推力を減少できる上、磁極部の磁極面の面積を大きくして、より大きな推力を有するシリンダ形リニア同期モータを得ることができる。また、固定子コア分割体のうち軸線方向の両端に位置する２つの固定子コア分割体の間に位置する固定子コア分割体は、それぞれ同じ形状を有しているので、軸線方向の両端に位置する２つの固定子コア分割体の形状を変えるだけで、コギングを低減できる。
【図面の簡単な説明】
【図１】本発明の実施の形態を説明するために用いる本発明の前提となるシリンダ形リニア三相同期モータ１の一部破断断面図である。
【図２】図１の半部横断面図である。
【図３】図１のシリンダ形リニア三相同期モータの固定子側の環状巻線の配置状態を説明するために用いる図である。
【図４】図１のシリンダ形リニア三相同期モータの固定子と可動子の関係を示す図である。
【図５】本発明の実施の形態のシリンダ型リニア同期モータに用いる固定子コアユニットの半部断面図である。
【図６】（Ａ）及び（Ｂ）は、固定子コア分割体のうち軸線方向の両端に位置する２つの固定子コア分割体の間に位置する固定子コア分割体の平面図及び一部切り欠き側面図である。
【符号の説明】
１シリンダ形リニア三相同期モータ
２７直動軸
２９磁石取付体
３１ａ〜３１ｈ円環状永久磁石
３２可動子
３５，１３５固定子コアユニット
１３６ｂ1 ヨーク構成部分
１３６ｂ2 磁極部
１３６ｂ6 磁極面
１３６ｂ7 磁極面形成部
１３６ｂ8 連結部
Ｒ１連結部の径方向内側端部の半径寸法
Ｒ２連結部の径方向外側部の半径寸法
Ｔ１連結部の径方向内側部の厚み寸法
Ｔ２連結部の径方向外側端部の厚み寸法[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cylinder type linear synchronous motor in which a mover moves linearly.
[0002]
[Prior art]
Currently, a cylinder type linear stepping motor (or linear pulse motor) is actually sold as a cylinder type linear motor. This commercially available cylinder-type linear stepping motor has a fixed structure composed of a plurality of stator cores having a plurality of small teeth formed on the inner peripheral surface along the axial direction of the linear motion shaft and wound with excitation windings. And a movable element including a movable part that is fixed to the linear motion shaft and includes a permanent magnet inside, and a plurality of small teeth formed on the outer peripheral surface along the axial direction of the linear motion shaft. In this linear stepping motor, the excitation windings of a plurality of stator cores are sequentially excited to generate thrust between the small teeth of the stator and the small teeth of the mover to linearly move the linear motion shaft. Although the linear stepping motor has high position control performance, it cannot obtain a large thrust.
[0003]
Therefore, the applicant has proposed a cylinder-type linear synchronous motor that can obtain a large thrust although the position control performance is inferior (Japanese Patent Application No. 10-130051).
[0004]
[Problems to be solved by the invention]
The cylinder type linear synchronous motor proposed by the applicant has a structure in which a plurality of annular windings are prepared in advance, and the corresponding annular windings are fitted in the corresponding slots of the stator core. However, in such a structure, it has been necessary to design and manufacture a stator core for each motor having a different axial length. There was also a problem that the assembly of the stator was troublesome. Further, there is a problem that the motor performance cannot be improved by narrowing the width of the opening of the slot facing the mover. An object of the present invention is to provide a cylinder-type linear synchronous motor including a stator having a structure in which an axial length can be arbitrarily set.
[0005]
Another object of the present invention is to provide a cylinder-type linear synchronous motor having a stator having a structure that can be easily assembled.
[0006]
Still another object of the present invention is to provide a cylinder-type linear synchronous motor having an annular winding and capable of narrowing the opening on the mover side of the slot.
[0007]
Still another object of the present invention is to provide a cylinder type linear synchronous motor in which magnetic saturation does not occur.
[0008]
Still another object of the present invention is to provide a cylinder type linear synchronous motor capable of reducing cogging thrust.
[0009]
[Means for Solving the Problems]
The mover used in the cylinder type linear synchronous motor of the present invention is a linear motion shaft that reciprocates in the axial direction, a magnet mounting portion fixed to the linear motion shaft, a magnet mounting portion fixed to the magnet mounting portion, and arranged in the axial direction of the linear motion shaft. One or more permanent magnet rows comprising a plurality of permanent magnets are provided. The plurality of permanent magnets constituting one permanent magnet row may be a plurality of permanent magnets physically combined. Alternatively, one magnetic body may be alternately arranged in the longitudinal direction with N and S poles. A plurality of permanent magnets that are magnetized to each other may be used. When there are a plurality of permanent magnet rows, it is preferable that the plurality of permanent magnet rows are arranged at substantially equal intervals in the circumferential direction. However, you may comprise the aggregate | assembly of a permanent magnet row | line | column using the annular | circular permanent magnet magnetized so that N pole or S pole may appear on the outer surface of radial direction. Specifically, an annular permanent magnet is fitted and fixed to the outer periphery of the magnet mounting body of the mover so that the N pole and the S pole are alternately arranged at a predetermined interval in the axial direction. When such a plurality of annular permanent magnets are used, the portions facing the plurality of magnetic pole portions of the stator core of the plurality of annular permanent magnets become the plurality of permanent magnets that respectively constitute the permanent magnet row. . When such an annular permanent magnet is used, not only the structure of the mover becomes simple, but also the attachment of the permanent magnet to the magnet attachment body becomes easy.
[0010]
The stator includes a plurality of annular windings that are formed by winding a winding conductor in an annular shape, are arranged at predetermined intervals in the axial direction, and are arranged so as to surround the periphery of the mover. The stator has a plurality of magnetic pole portions facing the permanent magnet row of the mover with a predetermined gap, and a yoke for magnetically connecting the plurality of magnetic pole portions, and corresponds between two adjacent magnetic pole portions. And a stator core unit having a plurality of magnetic pole portions arranged at intervals in the axial direction so as to form a slot for receiving at least a part of the annular winding. Here, the slot has an opening that opens toward the mover and a winding receiving portion that receives at least a part of the annular winding.
[0011]
In a cylinder type linear synchronous motor, a moving magnetic field is generated by changing the polarity of the magnetic poles appearing on the magnetic pole surfaces of multiple magnetic poles by changing the direction of excitation current flowing through the multiple annular windings (excitation windings) of the stator. And the thrust which displaces a linear motion axis to an axial direction between one or more permanent magnet rows and a plurality of magnetic pole parts is generated. If the exciting current is an alternating current, the polarity of the magnetic pole appearing on the magnetic pole surface of the magnetic pole portion changes according to the frequency. If a multi-phase alternating current is passed through a plurality of exciting windings, a multi-phase synchronous motor is obtained, so that a large thrust can be obtained. If the polarity and magnitude of the excitation current are fixed, only the attractive force acts between the stator and the mover, and the position of the mover is fixed.
[0012]
When exciting the magnetic pole part of the stator core unit, the winding conductor is wound around the outer periphery of the magnetic pole part according to the idea of the rotating electrical machine. If the idea of this rotating electrical machine is brought into a linear synchronous motor, the length in the axial direction becomes long and the winding work becomes difficult. Therefore, in the present invention, as the plurality of exciting windings of the stator, an annular winding formed by winding a winding conductor in an annular shape so as to surround the periphery of the mover in the circumferential direction is used. And the structure which fits at least one part of one cyclic | annular winding corresponding to the slot formed between the two magnetic pole parts adjacent to the axial direction of a stator core unit is employ | adopted. In this way, the magnetic flux generated by the excitation winding fitted in one slot flows so as to circulate through the two adjacent magnetic pole portions, and magnetic poles having different polarities are formed on the magnetic pole surfaces of the two adjacent magnetic pole portions. appear. By appropriately switching the excitation current flowing through the plurality of annular windings fitted in the plurality of slots of the one or more stator core units, the direction toward the other direction from the one axial direction to the stator side (or A moving magnetic field is obtained in the same state as if the N-pole and S-pole magnetic fields are moving at a predetermined speed (from the other direction toward one direction). This moving magnetic field corresponds to a rotating magnetic field used in a polyphase synchronous motor. By this moving magnetic field, thrust is generated between the plurality of magnetic pole portions of the stator core unit and the permanent magnet row of the mover, and the linear motion shaft moves in the axial direction. If the magnetic poles appearing on the magnetic pole surfaces of the plurality of magnetic pole portions of the stator core are made constant, only the attractive force is generated between the mover and the stator, and the mover is fixed.
[0013]
In the present invention, as the stator core unit, a plurality of stator core divided bodies having a combination structure portion that can be combined in the axial direction in the yoke portion corresponding to the slot of the stator core unit are combined in the axial direction. Use the structure of In the present invention, the stator core divided body is integrally formed of a magnetic conductive material, and has a structure having an annular yoke component portion and an annular magnetic pole portion that are arranged concentrically with the linear motion shaft. ing. The annular magnetic pole portion has an annular magnetic pole surface forming portion having a magnetic pole surface facing the permanent magnet row, and an annular connecting portion that connects the magnetic pole surface forming portion and the annular yoke component, The annular connecting portion has a structure in which the thickness is continuously reduced as the magnetic path cross-sectional area becomes substantially constant from the magnetic pole surface forming portion toward the yoke constituent portion. Here, “the part of the yoke corresponding to the slot” means that when the two stator core divided bodies are divided by the combination structure provided in the part, the slot is divided into two (or one slot has a shape). It is a portion that cannot be maintained), and is not limited to a portion in which the slot is completely divided into two.
[0014]
Here, as the structure of the combination structure portion that can be combined in the axial direction, a structure that is combined by a concave-convex fitting structure, or a concave portion or a slit that faces the yoke component part of the two stator core divided bodies is formed and faced. A well-known combination structure, such as a structure in which a common fitting member is fitted to both of the two recesses or slits, can be used.
[0015]
When the stator core unit is configured by combining a plurality of stator core divided bodies in the axial direction as in the present invention, depending on the number and shape of the stator core divided bodies combined with the length of the stator core unit. It can be arbitrarily determined. Therefore, it is not necessary to design and manufacture a new stator core unit even when the number of phases of the excitation winding is increased or the length of the permanent magnet row is increased to obtain a large thrust. Further, in the process of combining a plurality of stator core divisions, at least a part of the annular winding can be disposed between the slots, so that the combination of the stator core unit and the annular winding is facilitated, resulting in the stator The manufacturing and assembly of the can be facilitated. Further, when this structure is adopted, the space factor of the windings that can be accommodated in the slots can be increased as compared with the case where at least a part of the windings is pushed into the slots.
[0016]
In particular, in the present invention, the stator core divided body is integrally formed of a magnetic conductive material, and has a structure having an annular yoke component portion and an annular magnetic pole portion that are arranged concentrically with the linear motion shaft. Therefore, the stator core unit can be easily formed only by combining a plurality of stator core divided bodies, and the manufacture and assembly of the stator becomes easy. The annular magnetic pole portion includes an annular magnetic pole surface forming portion having a magnetic pole surface, and an annular connecting portion that connects the magnetic pole surface forming portion and the yoke component. Since the thickness is continuously reduced from the surface forming part toward the yoke component so that the magnetic path cross-sectional area is almost constant, magnetic saturation does not occur and the slot occupancy is increased. It is done.
[0017]
As a specific method of making the magnetic path cross-sectional area substantially constant from the magnetic pole surface forming portion toward the yoke constituent portion, an annular connecting portion is formed in a disc shape, and a radially inner portion of the annular connecting portion is formed. The radial dimension is R1, the thickness dimension of the radially inner portion of the annular coupling portion is T1, the radial dimension of the radially outer portion of the annular coupling portion is R2, and the thickness dimension of the radially outer portion of the annular coupling portion. Is set to T2, the thickness of the annular connecting portion may be continuously reduced so as to satisfy the condition of T1 × R1 = T2 × R2.
[0018]
If the thickness dimension T3 of the magnetic pole surface forming portion is set larger than the thickness dimension T1 so as to reduce the cogging thrust, the cogging thrust can be reduced and the magnetic pole surface area of the magnetic pole portion can be increased to increase the thrust force. A cylinder-type linear synchronous motor can be obtained. Moreover, since the stator core divided bodies positioned between two stator core divided bodies positioned at both ends in the axial direction of the stator core divided bodies have the same shape, the stator core divided bodies are disposed at both ends in the axial direction. Cogging can be reduced simply by changing the shape of the two stator core divisions positioned.
[0019]
In this way, in order to reduce the cogging thrust by setting the thickness dimension T3 of the magnetic pole surface forming portion to be larger than the thickness dimension T1, the gap between the pair of stator core segments located on both sides in the axial direction of the stator core unit is set. The thickness dimension of the magnetic pole surface forming portion of the plurality of stator core divided bodies positioned at the same position is made constant, and the thickness dimension of the magnetic pole surface forming portion of the pair of stator core divided bodies positioned on both sides in the axial direction of the stator core unit is A pair of dimensions A between the inner corners in the axial direction of the magnetic pole face of the magnetic pole face forming portion of the pair of stator core divisions located on both axial sides of the stator core unit and a pair located on both axial sides of the stator core unit What is necessary is just to determine so that the relationship with the dimension B between the outer side corner | angular parts of the magnetic pole surface of the magnetic pole surface formation part of a stator core division body of this may reduce cogging.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example of an embodiment of the present invention will be described in detail. FIG. 1 is a partially broken cross-sectional view of a cylinder-type linear three-phase synchronous motor 1 previously proposed by the applicant, which is a premise of the present invention, used to explain an embodiment of the present invention. FIG. A case 3 of the cylinder type linear three-phase synchronous motor 1 is composed of a cylinder-shaped frame 5 made of a non-magnetic material (for example, aluminum) and a pair of end brackets 7 and 9 made of aluminum. The frame 5 has a cylindrical cavity 5a inside, and has annular step portions 5b and 5b into which end brackets 7 and 9 are fitted inside the opening portions at both ends. Linear bearings 11 and 13 made of ball splines are fitted in the openings 7a and 9a at the center of the end brackets 7 and 9, respectively. The linear bearings 11 and 13 are fixed to the end brackets 7 and 9 by four screws 15. Annular grooves 7c and 9c that open radially outward are formed on the outer peripheral portions of the annular protrusions 7b and 9b that are fitted to the step portions 5b and 5b of the frame 5 of the pair of end brackets 7 and 9. O-rings 17 and 19 for sealing are fitted in the grooves 7c and 9c. As shown in FIG. 2, the end brackets 7 and 9 are integrally provided with flange portions 7d and 9d having a substantially quadrangular outline shape, and mounting bolts are inserted into the four corners of the flange portions. Holes 21 and 23 are respectively formed. Note that the end brackets 7 and 9 are fixed to the frame 5 by screws 25.
[0021]
A pair of linear bearings 11 and 13 support an iron linear motion shaft 27 so as to be capable of linear reciprocation. The state shown in FIG. 1 is a state in which the output shaft portion 27a to which the load of the linear motion shaft 27 is connected protrudes to the outermost side. An iron magnet mounting body 29 made of a magnetic material is fixed to a portion of the linear motion shaft 27 located inside the case 3 so as to be concentric with the linear motion shaft 27. The magnet attachment body 29 basically has a cylindrical shape, and has a fitting hole 29a fitted to the outer periphery of the linear motion shaft 27 and an inner side of the fitting body 29 located on both sides of the fitting hole 29a. First and second large-diameter holes 29b and 29c having a diameter larger than that of the fitting hole 29a are formed. The first large diameter hole 29 b has a diameter that does not contact the outer peripheral surface of the inner end portion of the linear bearing 11, and the second large diameter hole 29 c also does not contact the outer peripheral surface of the linear bearing 13. have. On the outer periphery of the portion of the magnet mounting body 29 where the first large-diameter hole 29b is formed (the end of the linear motion shaft 27 on the output shaft portion 27a side), a detected portion 51 of a position detection sensor described later is provided. A step portion 29d to which the used linear scale is attached is formed. Further, the outer peripheral portion of the portion where the second large diameter hole 29 c is formed constitutes the magnet attachment portion 30. The magnet mounting portion 30 has a substantially cylindrical shape extending in the axial direction of the linear motion shaft 27, and eight annular permanent magnets 31a to 31h are fitted on the outer periphery thereof. A substantially annular or C-shaped stopper member 33 made of a non-magnetic material and partially cut off is fitted between two adjacent annular permanent magnets and on the outer side in the axial direction of the annular permanent magnet 31h. . A fitting groove into which the stopper members 33 are fitted is formed on the outer peripheral portion of the magnet mounting portion 30. The annular permanent magnets 31a to 31h may be fixed to the magnet mounting portion 30 via an adhesive, or the entire annular permanent magnets 31a to 31h may be molded with a synthetic resin. Further, after the heat shrinkable tube is put on the outside of the magnet mounting portion 30 fitted with the annular permanent magnets 31a to 31h, the heat shrinkable tube is heated and thermally contracted, so that the annular permanent magnets 31a to 31h are entirely formed. You may make it wrap in. The annular permanent magnets 31a, 31c, 31e and 31g are magnetized so that N poles appear on the outer surface in the radial direction, and the annular permanent magnets 31b, 31d, 31f and 31h are S poles on the outer surface in the radial direction. Is magnetized so that appears. As a result, a row of permanent magnets in which N poles and S poles are alternately arranged in the axial direction of the linear motion shaft 27 is formed. A plurality of permanent magnets in which the respective annular permanent magnet portions facing the seven magnetic pole portions of six stator core units 35... Described later are arranged at predetermined intervals in the circumferential direction in the present invention. A plurality of permanent magnets constituting the row are formed. In this example, the movable element 32 is constituted by the linear motion shaft 27, the magnet attachment body 29, and the annular permanent magnets 31a to 31h.
[0022]
Note that the magnet mounting body 29 can be fixed to the linear motion shaft 27 in any way, but in this example, the pins 34 are fitted into the four fitting holes provided in the circumferential direction at two locations on the linear motion shaft 27. Thus, the magnet attachment body 29 is fixed to the linear motion shaft 27.
[0023]
Stator core units 35 are fixed to the inner periphery of the frame 5. The stator core unit 35 is a permanent magnet array in which a base portion fixed on the inner peripheral side of the frame 5, that is, a magnetic pole surface 35b in the radial direction of the linear motion shaft 27 is formed by annular permanent magnets 31a to 31h. .. And seven magnetic pole portions 35c arranged at predetermined intervals in the axial direction of the linear motion shaft 27.
[0024]
The stator core unit 35 is configured by combining seven stator core divided bodies 36a to 36g in the axial direction. The stator core divided bodies 36 a to 36 g have a combination structure portion that can be separated in the axial direction at a portion of the yoke 35 a corresponding to the central portion of the slot of the stator core unit 35. Each of the stator core divided bodies 36a to 36g has one magnetic pole part 35c and a yoke component that constitutes a part of the yoke 35a. The combination surface (abutment surface) of two adjacent stator core divided bodies is formed with a combinable concave portion and a convex portion constituting the combined structure portion, respectively, and two adjacent stator core divided bodies are formed. Are connected to each other by the combination structure. Of the stator core divided bodies 36a to 36g, the two stator core divided bodies 36a and 36g located at both ends in the axial direction have the same shape, and between the two stator core divided bodies 36a and 36g. The five stator core divided bodies 36b to 36e located at the same position also have the same shape.
[0025]
In six slots formed between two adjacent magnetic pole portions 35c of each stator core unit 35, one of annular windings 39a to 39f constituting an excitation winding formed by winding a winding conductor in an annular shape. Each part is fitted. In the example of FIG. 1, each of the annular windings 39 a to 39 f is configured by winding a winding conductor around a bobbin 41 made of synthetic resin. Is fitted.
[0026]
The annular windings 39a to 39f are sequentially sandwiched between two stator core divided bodies when the six stator core units 35 are assembled together by combining the stator core divided bodies 36a to 36g. Specifically, seven stator core divided bodies 36a for constituting six stator core units 35 are arranged in an annular shape on an assembly jig at a predetermined interval, and an annular winding is formed thereon. Line 39a is placed. Next, the six stator core divided bodies 36b are combined on the six stator core divided bodies 36a with the annular winding 39a interposed therebetween. Thereafter, the annular windings 39b to 39f and each of the six stator core divided bodies 36c to 36g are sequentially stacked in the same manner to assemble six stator core units 35. Finally, the stator core divided bodies 36a to 36g are integrated by irradiating a laser to the coupling portions of the stator core divided bodies 36a to 36g.
[0027]
In this example, the stator core unit 35, the annular windings 39a to 39f, and the stopper member 37 are molded with an insulating mold material to form a mold portion 45. In FIG. 1, the mold part 45 is indicated by a broken line. The stopper surface 5d and the stopper member 37 receive a reaction force in the axial direction acting on the stator core units 35, so as to prevent the stator core units 35 from being displaced in the axial direction. Because of this function, it is possible to prevent the mold portion 45 from being cracked and the like by applying a force to the mold portion 45. In this example, a stator 47 is configured by the stator core units 35 and the annular windings 39a to 39f.
[0028]
Unlike the linear stepping motor, the linear synchronous motor requires a position detection sensor for detecting the positional relationship between the movable element 32 and the stator 47 in order to switch the excitation current flowing through the annular windings 39a to 39f. To do. Although it is conceivable to provide a position detection sensor so as to detect the displacement of the linear motion shaft 27 protruding outside the case, this is inconvenient because it cannot be handled in the same manner as an existing motor. This also causes a problem that the detection error due to thermal expansion of each member due to temperature change becomes large and the position control accuracy deteriorates. Therefore, in this example, as shown in FIG. 1, a position detection sensor 49 that detects the positional relationship between the mover 32 and the stator 47 in the axial direction is arranged inside the frame 5. The position detection sensor 49 is attached to the movable element 32 and can be detected optically or magnetically, and the position detection sensor 49 is fixed to the inner periphery of the frame 5 to optically detect the position or movement amount of the detection part 51. Or a detection unit 53 that detects magnetically or magnetically. In a position detection sensor that optically detects a position, a linear scale having a predetermined reflection pattern is used as the detected part 51. Then, the position is detected based on the information included in the light reflected by irradiating the detected portion 51 with light from the detecting portion 53 including the light emitting portion and the light receiving portion. In this example, the magnet attachment body 29 and the frame 5 of the mover 32 are formed of materials having different thermal expansion coefficients. Therefore, the detected portion 51 is disposed at a position close to the output shaft portion 27a to which the load of the linear motion shaft 27 is connected, and the detection portion 53 is also disposed at a position close to the output shaft portion 27a. When heat transmitted from the load side through the output shaft portion 27a of the linear motion shaft 27 is transmitted to the inside of the case 3 of the motor 1 through the linear motion shaft 27, the linear motion shaft 27, the magnet mounting body 29, and the frame 5 are thermally expanded. Wake up. If the position detection sensor is arranged on the non-output shaft portion 27b side opposite to the output shaft portion 27a of the linear motion shaft 27, the expansion of each part located on the non-output shaft portion side 27b from the output shaft portion 27a side is accumulated. It appears as a change in the mounting position of the detected part and the detecting part. On the other hand, when the detected portion 51 and the detecting portion 53 of the position detection sensor 49 are arranged at positions close to the output shaft portion side of the linear motion shaft 27 as in this example, the attachment positions of the detected portion 51 and the detecting portion 53 are arranged. Since the cumulative value of thermal expansion that changes is small, the detection accuracy of the position detection sensor 49 is increased, and the positioning accuracy of the linear synchronous motor is increased accordingly.
[0029]
In the example of FIG. 1, the end bracket 9 on the side where the linear bearing 13 that supports the end portion on the non-output shaft portion 27 b side to which the load of the linear motion shaft 27 is not connected is attached is a linear motion shaft that protrudes from the end bracket 9. A cover member 55 made of metal or synthetic resin is attached to cover the end portion of the non-output shaft portion 27b on the 27 side. When the cover member 55 is provided, the non-output shaft portion 27b of the linear motion shaft 27 and the linear bearing portion 13 can be protected. In particular, in this example, a cover member 55 having a waterproof structure is used. Specifically, an annular fitting groove that opens in a direction toward the outer surface of the end bracket 9 is formed in the flange portion 55a of the cover member 55, and a sealing O-ring 57 is compressed in the fitting groove. Are mated. The cover member 55 is screwed to the end bracket 9 by inserting screws into a plurality of through holes (not shown) provided in the flange portion 55a. With such a structure, moisture can be prevented from entering the motor from the non-output shaft portion 27b side of the linear motion shaft 27. Such a function is particularly effective when the linear three-phase synchronous motor 1 is used in such a posture that the linear motion shaft 27 is displaced in the vertical direction so that the non-output shaft portion side 27b of the linear motion shaft 27 is located on the upper side. Demonstrate.
[0030]
In the cylinder-type linear synchronous motor, the polarity of the magnetic poles appearing on the magnetic pole surfaces 35b of the stator core units 35 is changed by changing the energization direction of the excitation current flowing through the annular windings 39a to 39f of the stator 47. As a result, a moving magnetic field is generated, and a thrust force is generated between the permanent magnet row of the mover 32 and the magnetic pole portion 35c of the stator 47 to displace the linear motion shaft 27 in the axial direction. In this example, a sinusoidal three-phase alternating current is used as the excitation current. Depending on the frequency of the three-phase alternating current, the polarity of the magnetic poles appearing on the magnetic pole surfaces 35b of the magnetic pole portions 35c changes. If a multi-phase alternating current is passed through the annular winding, a multi-phase synchronous motor is obtained, so that a large thrust can be obtained. If the exciting current is not changed (if the polarity and size are fixed), only the attractive force acts between the stator 47 and the movable element 32, and the position of the movable element 32 is fixed.
[0031]
Excitation modes of the annular windings 39a to 39f in this example will be briefly described with reference to FIGS. First, in this example, three-phase excitation currents U, V, and W whose phases are shifted by 120 degrees in electrical angle are used. Therefore, a U-phase exciting current is passed through the two annular windings 39a and 39b fitted in the two adjacent slots of the six stator core units 35, and then the two adjacent slots The two annular windings 39c and 39d fitted to the two are supplied with a V-phase excitation current, and then the two annular windings 39e and 39f fitted to the two adjacent slots are connected to W. Apply phase excitation current. Then, the six annular windings 39a to 39f are connected so that the polarities appearing at the two magnetic pole portions 35c... Adjacent to each other in the axial direction of the six stator core units 35. In this example, in order to generate the flow of magnetic flux shown in FIG. 3, the lead wires are connected to the annular windings 39a and 39b through which the U-phase excitation current flows so that the U-phase excitation current flows in the opposite direction. Then, a U-phase power supply line is connected to the connected lead wire. In addition, the symbol shown in FIG. 3 has shown the direction through which an electric current flows. The annular windings 39c and 39d through which the V-phase excitation current flows are also connected to lead wires so that the V-phase excitation current flows in the opposite direction, and the V-phase power supply line is connected to the connected lead wires. Similarly, the annular windings 39e and 39f through which the W-phase excitation current flows are also connected to lead wires so that the W-phase excitation current flows in the opposite direction, and the W-phase power supply wires are connected to the connected lead wires. Connecting.
[0032]
By connecting the excitation current flowing in each annular winding based on the output of the position detection sensor 49 and generating a moving magnetic field that apparently moves in the axial direction based on the output of the position detection sensor 49, the same principle as that of the synchronous motor is obtained. The moving element 32 moves in the axial direction according to the operating principle. If the switching of the excitation current is stopped, only the attractive force acts between the mover 32 and the stator 47, and the mover 32 stops.
[0033]
The excitation mode used in this example is generally described as follows. First, in order to obtain a moving magnetic field by applying a p-phase (p is a positive integer greater than or equal to 2) exciting current to a plurality of annular windings, m (where m is a positive integer greater than or equal to 2). When using this stator core unit, m stator core units are arranged at substantially equal intervals in the circumferential direction. Further, p × q (where q is a positive integer of 1 or more) annular windings are prepared as a plurality of annular windings. If n magnetic pole portions are provided in one stator core unit, n has a relationship of n = p × q + 1 in this case. Then, a part of one corresponding annular winding is fitted in each of n−1 slots formed between two magnetic pole portions adjacent to each other in the axial direction of the m stator core units. In this way, a completely synchronized moving magnetic field can be generated from the n magnetic pole portions of the m stator core units. Since it is only necessary to fit the annular winding into the slot, the stator can be easily configured even when the axial dimension of the slot (the interval between two adjacent magnetic pole portions) becomes narrow. When the thrust is increased by using the multiphase excitation current, the q phase windings are fitted to the q annular windings fitted in the q slots arranged continuously in the axial direction of the m stator core units. Apply excitation current. Even at this time, p × q annular windings are connected so that the polarities appearing at the two magnetic pole portions adjacent to each other in the axial direction of the m stator core units become different polarities. In this way, the wiring is not complicated even when the number of phases is increased. In order to increase or decrease the thrust, it is only necessary to increase or decrease the number of annular windings through which exciting currents of the same phase flow.
[0034]
FIG. 5 is a half sectional view of stator core unit 135 used in the cylinder type linear synchronous motor according to the embodiment of the present invention. The stator core unit 135 is configured by combining ten stator core divided bodies 136 a to 136 j in the axial direction of the linear motion shaft 27. The stator core divided bodies 136a to 136j have a combination structure portion that can be separated in the axial direction at a portion of the yoke 135a corresponding to the central portion of the slot of the stator core unit 135. Specifically, this combination structure part is constituted by a concave part and a convex part of a projecting part 136b4 and 136b5 of a yoke constituent part 136b1 which will be described later, and two adjacent stator core divided bodies are formed by the combination structure part. Are interconnected. Of the stator core divided bodies 136a to 136j, the eight stator core divided bodies 136b to 136i located between the two stator core divided bodies 136a and 136j located at both ends in the axial direction have the same shape, respectively. ing. 6A and 6B are a plan view and a partially cutaway side view of one of these eight stator core divided bodies 136b to 136i (136b). The stator core divided body 136b is integrally formed of a magnetic conductive material, and has an annular yoke component 136b1 and an annular magnetic pole portion 136b2 that are arranged concentrically with the linear motion shaft 27. The yoke component 136b1 has an annular component body 136b3 and two annular protrusions 136b4 and 136b5 projecting from the component body 136b3 to both axial sides of the linear motion shaft 27. The protrusions 136b4 and 136b5 constitute a combined structure part of unevenness that can be separated from the protrusions facing each other of the adjacent stator core divided bodies. The magnetic pole portion 136b2 is an annular magnetic pole surface forming portion 136b7 having a magnetic pole surface 136b6 facing the permanent magnet row of the mover 32, and a circular plate that connects the magnetic pole surface forming portion 136b7 and the yoke component 136b1. And a connecting portion 136b8. The yoke component 136b1 and the connecting portion 136b8 are formed with a notch recess LH for drawing out the lead wire of the annular winding, and the connecting portion 136b8 and the magnetic pole surface forming portion 136b7 are annularly connected to the notch recess LH. A groove LR for receiving the lead wire of the winding is formed. The connecting portion 136b8 has a structure in which the thickness is continuously reduced so that the magnetic path cross-sectional area becomes substantially constant from the magnetic pole surface forming portion 136b7 toward the yoke constituent portion 136b1. Specifically, the radial dimension of the radially inner part of the coupling part 136b8 is R1, the thickness dimension of the radially inner part of the coupling part 136b8 is T1, and the radial dimension of the radially outer part of the coupling part 136b8 is R2. When the thickness dimension of the radially outer portion of the connecting portion 136b8 is T2, the thickness of the connecting portion 136b8 is continuously reduced so as to satisfy the condition of T1 × R1 = T2 × R2. As in this example, magnetic saturation does not occur if the thickness of the connecting portion 136b8 is continuously reduced so that the magnetic path cross-sectional area becomes substantially constant from the magnetic pole surface forming portion 136b7 toward the yoke constituent portion 136b1. Further, the thickness dimension T3 of the magnetic pole surface forming portion 136b7 is set larger than the thickness dimension T1 of the radially inner end portion of the coupling portion 136b8. That is, the magnetic pole surface forming portion 136b7 has an annular forming portion main body 136b9 and two annular shoulder portions 136b10 and 136b11 projecting from the forming portion main body 136b9 in the axial direction of the linear motion shaft 27. If the thickness dimension T3 of the magnetic pole surface forming portion 136b7 is set larger than the thickness dimension T1 of the radially inner end portion of the coupling portion 136b8 as in this example, the cogging thrust can be reduced and the area of the magnetic pole surface 136b6 is increased. Thus, a cylinder type linear synchronous motor having a larger thrust can be obtained.
[0035]
Of the stator core divided bodies 136a to 136j, the stator core divided bodies 136a and 136j located at both ends in the axial direction of the linear motion shaft 27 are also integrally formed of a magnetic conductive material in the same manner as the stator core divided body 136b. As shown in FIG. 5, it has annular yoke component parts 136a1, 136j1 and annular magnetic pole parts 136a2, 136j2 arranged concentrically with the linear motion shaft 27, respectively. The yoke component 136a1 of the stator core divided body 136a at the left end as viewed in the drawing has an annular component main body 136a3 and one annular protrusion protruding from the component main body 136a3 toward the adjacent stator core divided body 136b. Part 136a5. The yoke component 136j1 of the stator core divided body 136j at the right end as viewed in the drawing is an annular component main body 136j3 and one annular protrusion protruding from the component main body 136j3 toward the adjacent stator core divided body 136i. Part 136j4. The magnetic pole portions 136a2 and 136j2 include annular magnetic pole surface forming portions 136a7 and 136j7 having magnetic pole surfaces 136a6 and 136j6 facing the permanent magnet row of the mover 32, magnetic pole surface forming portions 136a7 and 136j7, and yoke components 136a1 and 136j1, respectively. And annular connecting portions 136a8 and 136j8 each having a disk shape for connecting the two. The stator core divided bodies 136a to 136j are not formed into a complete ring shape because a through groove (not shown) extending in the radial direction is formed to draw out the lead wire of the ring winding. However, such a case is also included in the present application in the form of a ring. The connecting portions 136a8 and 136j8 have a structure in which the thickness continuously decreases as the magnetic path cross-sectional areas become substantially constant from the magnetic pole surface forming portions 136a7 and 136j7 toward the yoke constituent portions 136a1 and 136j1. . The magnetic pole face forming portion 136a7 of the stator core divided body 136a at the left end as viewed in the drawing has an annular forming portion main body 136a9 and one annular protruding from the forming portion main body 136a9 toward the adjacent stator core divided body 136b. A shoulder 136a11 is provided. The magnetic pole face forming portion 136j7 of the stator core divided body 136j at the right end as viewed in the drawing has an annular forming portion main body 136j9 and one annular protruding from the forming portion main body 136j9 toward the adjacent stator core divided body 136i. It has a shoulder 136j10. The thickness dimension of the magnetic pole surface forming portions 136a7 and 136j7 is the dimension between the inner corners in the axial direction of the magnetic pole surfaces 136a6 and 136j6 of the magnetic pole surface forming portions 136a7 and 136j7 (the dimension between the shoulder portion 136a11 and the shoulder portion 136j10). ) A and the dimension B between the outer corners in the axial direction of the magnetic pole surfaces 136a6 and 136j6 of the magnetic pole surface forming portions 136a7 and 136j7 are determined so as to reduce cogging. In this example, the dimension A between the inner corners is set to 93.4 mm, and the dimension B between the outer corners is set to 101.4 mm. Further, taper portions that are inclined at an angle of 45 ° from the magnetic pole surfaces 136a6 and 136j6 are formed on the outer sides of both end portions in the axial direction of the magnetic pole surface forming portions 136a7 and 136j7.
[0036]
The excitation mode or method of the annular winding described in the above example is an example, and the excitation method of the annular winding in the case of implementing the present invention is arbitrary as long as it can generate a moving magnetic field.
[0037]
【The invention's effect】
According to the present invention, since the stator core unit is configured by combining a plurality of stator core divided bodies in the axial direction, the length of the stator core unit is arbitrarily determined depending on the number and shape of the stator core divided bodies combined. There are benefits that can be determined. Therefore, the design is easy even when the number of phases of the excitation winding is increased or when the length of the permanent magnet row is increased to obtain a large thrust. In addition, in the process of combining a plurality of stator core divisions, at least a part of the annular winding can be arranged to fit between the slots, so that the combination of the stator core unit and the annular winding is facilitated. As a result, there is an advantage that manufacturing and assembling of the stator becomes easy. Further, when this structure is adopted, there is an advantage that the space factor of the winding that can be accommodated in the slot can be increased as compared with the case where at least a part of the winding is pushed into the slot.
[0038]
In particular, in the present invention, the stator core divided body is integrally formed of a magnetic conductive material, and has a structure having an annular yoke component portion and an annular magnetic pole portion that are arranged concentrically with the linear motion shaft. Therefore, the stator core unit can be easily formed only by combining a plurality of stator core divided bodies, and the manufacture and assembly of the stator becomes easy. In addition, since the annular connecting portion has a structure in which the thickness is continuously reduced so that the magnetic path cross-sectional area becomes substantially constant from the magnetic pole surface forming portion toward the yoke constituent portion, magnetic saturation does not occur. In addition, the slot occupancy can be increased. Further, since the thickness T3 of the magnetic pole surface forming portion is set larger than the thickness T1 so as to reduce the cogging thrust, the cogging thrust can be reduced and the magnetic pole surface area of the magnetic pole portion can be increased to be larger. A cylindrical linear synchronous motor having thrust can be obtained. Moreover, since the stator core divided bodies positioned between two stator core divided bodies positioned at both ends in the axial direction of the stator core divided bodies have the same shape, the stator core divided bodies are disposed at both ends in the axial direction. Cogging can be reduced simply by changing the shape of the two stator core divisions positioned.
[Brief description of the drawings]
FIG. 1 is a partially cutaway sectional view of a cylinder type linear three-phase synchronous motor 1 which is a premise of the present invention and is used for explaining an embodiment of the present invention.
2 is a half cross-sectional view of FIG. 1. FIG.
FIG. 3 is a diagram used for explaining an arrangement state of annular windings on the stator side of the cylinder type linear three-phase synchronous motor of FIG. 1;
4 is a diagram illustrating a relationship between a stator and a mover of the cylinder type linear three-phase synchronous motor of FIG. 1; FIG.
FIG. 5 is a half sectional view of a stator core unit used in a cylinder type linear synchronous motor according to an embodiment of the present invention.
FIGS. 6A and 6B are a plan view and a part of a stator core divided body positioned between two stator core divided bodies located at both ends in the axial direction of the stator core divided body. It is a notch side view.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cylinder type linear three-phase synchronous motor 27 Linear motion shaft 29 Magnet attachment bodies 31a-31h Annular permanent magnet 32 Mover 35, 135 Stator core unit 136b1 Yoke component 136b2 Magnetic pole part 136b6 Magnetic pole face 136b7 Magnetic pole face forming part 136b8 Connection Part R1 Radial dimension R2 of the radially inner end of the coupling part Radial dimension T1 of the radially outer part of the coupling part Thickness dimension T2 of the radially inner part of the coupling part Thickness dimension of the radially outer end of the coupling part

Claims

One or more permanent magnet arrays comprising a linear motion shaft that reciprocates in the axial direction, a magnet mounting portion fixed to the linear motion shaft, and a plurality of permanent magnets fixed to the magnet mounting portion and arranged in the axial direction of the linear motion shaft A mover comprising:
A plurality of annular windings formed by winding a winding conductor in an annular shape, arranged at a predetermined interval in the axial direction and arranged to surround the periphery of the mover, and the permanent magnet of the mover A plurality of magnetic pole portions opposed to the row with a predetermined gap, and a yoke for magnetically coupling the plurality of magnetic pole portions, and at least a part of the annular winding corresponding between two adjacent magnetic pole portions A cylinder type linear synchronous motor comprising a stator having a stator core unit in which the plurality of magnetic pole portions are arranged at intervals in the axial direction so as to form a slot for receiving
In the stator core unit, a plurality of stator core divided bodies having a combination structure portion that can be combined in the axial direction at a portion of the yoke corresponding to the slot of the stator core unit is combined in the axial direction. Configured,
The stator core divided body is integrally formed of a magnetic conductive material, and has an annular yoke component portion and an annular magnetic pole portion that are arranged concentrically with the linear motion shaft,
The annular magnetic pole portion includes an annular magnetic pole surface forming portion having a magnetic pole surface facing the permanent magnet row, and an annular coupling portion that connects the magnetic pole surface forming portion and the annular yoke component.
The cylinder-type linear synchronous motor is characterized in that the annular connecting portion continuously decreases in thickness from the magnetic pole surface forming portion toward the yoke constituent portion so that the magnetic path cross-sectional area becomes substantially constant.

The annular connecting portion has a disk shape, the radial dimension of the radially inner portion of the annular connecting portion is R1, the thickness dimension of the radially inner portion of the annular connecting portion is T1, When the radial dimension of the radially outer part of the annular coupling part is R2, and the thickness dimension of the radially outer part of the annular coupling part is T2,
T1 × R1 = T2 × R2
The cylinder type linear synchronous motor according to claim 1, wherein the annular connecting portion is continuously thin so as to satisfy the following condition.

The cylinder type linear synchronous motor according to claim 2, wherein a thickness dimension T3 of the magnetic pole surface forming portion is set larger than the thickness dimension T1 so as to reduce a cogging thrust.