JP3616338B2

JP3616338B2 - Electric motor rotor

Info

Publication number: JP3616338B2
Application number: JP2001016123A
Authority: JP
Inventors: 勲伊藤; 直樹木村; 鐘治真野
Original assignee: アイチエレック株式会社
Priority date: 2001-01-24
Filing date: 2001-01-24
Publication date: 2005-02-02
Anticipated expiration: 2021-01-24
Also published as: JP2002223538A

Description

【０００１】
【発明の属する技術分野】
本発明は、産業用機器、事務用機器、家電用機器に使用される電動機の回転子に関する。
【０００２】
【従来の技術】
近年、産業用機器、事務用機器、家電用機器に使用する電動機において永久磁石を使用した永久磁石形電動機が一般的に使用されるようになってきている。永久磁石形電動機の回転子には、永久磁石の磁束量によるマグネットトルクや回転子内部に磁束通路を確保しリラクタンストルクを利用した多種多様の回転子の構造が提案されている。従来、電動機性能を上げる場合、回転子内部に埋め込んだ永久磁石の材質を高性能化したり使用量を増やして対応してきたがコスト及び回転子の構造上限界があった。
【０００３】
この問題において図８のような回転子が提案されている。図８は三相４極の電動機に使用される永久磁石埋め込み形の回転子であり、隣り合う永久磁石４は異極となるように配置されている。回転子軸孔５を中心とした回転子鉄心１には、永久磁石４を挿入するための収容孔２が回転子外周に対して逆向きの円弧形状に配置されている。この円弧形状の収容孔２の回転子外周近傍には空隙３が設けられている。この空隙３は、永久磁石４によって発生した磁束を図中に示したｄ軸方向に集中させるために磁極中心の方向に大きく形成されている。これにより、磁束は磁極中心に集中することになり電動機の制御側から見た非通電区間の磁束を、通電区間に集中させることができ永久磁石の磁束を無駄なく利用し電動機の性能を向上させている。
【０００４】
【発明が解決しようとする課題】
しかしながら、このような電動機においては磁束を集中させ電動機の性能を向上できる反面、各極間における磁束の流出入の差が非常に大きくなり電動機のコギングトルクに起因する音、振動等が発生している。
【０００５】
特に、電動機の出力が大きく過負荷になると電動機のコギングトルクに起因する音、振動等が顕著に表れてくる。
【０００６】
また、特に大型化され電動機において回転子鉄心１に永久磁石４が挿入される収容孔２の回転子外周近傍に設けられた空隙３は、磁束を磁極中心に集中させ磁極中心に向かい大きく形成されており、また、磁束が漏れない様に空隙３と回転子外周との間の継鉄部分の幅を非常に細長く幅狭としているため強度不足となり、回転子製作時の取り扱いによっては、この継鉄部分の回転子外周が変形し固定子内径とのギャップが不均一となり品質面において重要な問題となっている。このことは電動機の性能低下及び電動機のコギングトルクに起因する音、振動等となって表れてくる。
【０００７】
【課題を解決するための手段】
固定子の内部に回転子を有する内転型の電動機であって、回転子には永久磁石が埋め込まれた凹字形状収容孔を備え、回転子の軸孔を中心として凹字形状収容孔の端部が回転子外周まで伸びて形成されており、この凹字形状収容孔の端部と回転子外周の間には空隙を有し、この空隙は、回転子外周から回転子鉄心の一部が回転子内径方向に凸字状に突出する凸字形状回転子鉄心を形成する凹字形状空隙とした電動機の回転子とすることにより達成することができる。
【０００８】
また、この凹字形状空隙と永久磁石を埋め込むための凹字形状収容孔とを連結することによって達成することができる。
【０００９】
また、この回転子が積厚方向に複数に分割されており、永久磁石が挿入される凹字形状収容孔及び凹字形状空隙が回転子の周方向に所定の角度分ずらした電動機の回転子とすることによって達成することができる。
【００１０】
また、この回転子が積厚方向に複数に分割されており、永久磁石が挿入される凹字形状収容孔をずらすことなく、凹字形状空隙のみ回転子の周方向に所定の角度分ずらした電動機の回転子とすることによって達成することができる。また、凹字形状空隙を磁極中心に向かい所定の角度分伸ばすことによっても同様の効果を得ることができる。
【００１１】
また、凹字形状空隙が回転子の周方向に固定子のスロットピッチの１／２の角度分ずれている電動機の回転子とすることによって達成することができる。
【００１２】
また、固定子の歯部に直接巻線が巻かれた集中巻方式の固定子と対向配置した電動機の回転子とすることによって達成することができる。
【００１３】
また、前記回転子には永久磁石が埋め込まれた凹字形状収容孔を備え、この回転子の軸孔を中心として凹字形状収容孔の端部が回転子外周まで伸びて形成されており、この凹字形状収容孔の端部と回転子外周の間には空隙を有し、この空隙は、回転子外周から回転子鉄心の一部が回転子内径方向に凸字状に突出する凸字形状回転子鉄心を形成する凹字形状空隙とした電動機の回転子において、前記回転子が積厚方向に複数に分割され、凹字形状空隙が回転子の周方向に所定の角度分ずれている回転子を、ハウジングに組み込まれた後に固定子を着磁ヨークとして着磁をする回転子の着磁方法とする。
例えば、冷蔵庫及びエアコン等の駆動源とする密閉圧縮機内において固定子と回転子が組み込まれた後に、固定子を着磁ヨークとして回転子を着磁することができる。
【００１４】
【発明の実施の形態】
本発明の実施例について図面を用いて説明する。図１は、回転子鉄心１内部に永久磁石４ａを挿入する凹字形状収容孔２ａを有し、隣り合う凹字形状収容孔２ａに挿入された永久磁石４ａとは異極をなし４極を形成している。凹字形状収容孔２ａには永久磁石４ａが中央部底部と凹字形状収容孔側部とに分割された平板永久磁石が挿入されている。この凹字形状収容孔２ａと回転子外周部との間には、凹字形状空隙３ａを有している。凹字形状空隙３ａの底部を、凹字形状収容孔２ａの端部に面して配置し、凹字形状空隙３ａの端部を回転子外周に向かうように配置している。従って、回転子外径から見た場合、回転子鉄心１の一部分が回転子内径方向に凸字状に突出する凸字形状回転子鉄心６が形成されている。
【００１５】
回転子磁極中心側に位置する凹字形状空隙３ａの端部３ａ’と回転子外周部との間の幅は、好ましくは０．３５ｍｍ〜２．０ｍｍ程度がよく、回転子と固定子の間に発生する磁束が飽和するようにしている。磁束密度としては、２．０Ｔ程度となればよい。つまり、磁束を磁極中心に集中させるため凹字形状収容孔２ａに埋め込まれた永久磁石４ａによって発生する磁束を、この凹字形状空隙３ａの端部３ａ’により強制的に磁極中心に向くようにし磁束の漏れを防いでいる。このことにより、電動機の性能に寄与するマグネットトルクを上げることができ総合トルクを上げることができる。
【００１６】
また、回転子磁極極間側に位置する凹字形状空隙３ａの端部３ａ’’と回転子外周部との間の幅は、前述した磁極中心側に位置する凹字形状空隙３ａの端部３ａ’幅と同様に、好ましくは０．３５ｍｍ〜２．０ｍｍ程度がよく回転子と固定子の間に発生する磁束が飽和するようにしている。この場合も、磁束密度としては、２．０Ｔ程度となればよく、また、この凹字形状空隙３ａの端部３ａ’’を凹字形状収容孔２ａの幅より大きく磁極極間部まで張り出すことにより永久磁石４ａを埋め込んだ凹字形状収容孔２ａと回転子軸孔５との間に位置する回転子鉄心１の磁路の回転子外周近傍においてリラクタンストルクを集中させることができ総合トルクを上げることができる。
【００１７】
また、凹字形状空隙３ａの中央の凸字回転子鉄心６は、凹字形状空隙部３ａの端部３ａ’及び３ａ’’と回転子外周部との間の幅より幅広となっている。この凹字形状空隙部３ａの端部３ａ’及び３ａ’’より幅広の凸字回転子鉄心６があることにより、リラクタンストルクを集中させた磁極極間部からマグネットトルクを集中させた磁極中心に向かい段階的に磁束を変化させ流すことができる。
【００１８】
この実施例を図２において固定子鉄心７と回転子鉄心１を使用して説明する。固定子鉄心７のスロットには図示しないが固定子巻線が装着されている。固定子鉄心７からの磁束は回転子鉄心１を介して再び固定子鉄心７に入る。図中の矢印は、磁束の流れを示している。この磁束は、電動機が高負荷で運転されるものや大型化されたものでは、回転子と固定子間で非常に大きな磁束の疎密として表れる。従って、凸字形状回転子鉄心６を設けることにより段階的に磁束を流すことができる。つまり、凹字形状空隙３ａを介して磁極中心側へ磁束が流れることとなるため急激な磁束の変化がおこることがなくなる。この場合、磁極極間部側の凹字形状空隙３ａの端部３ａ’’側の空隙幅が磁極中心側の端部３ａ’側の空隙幅より幅広に設定するのが好ましい。これは磁極極間側への磁束の漏れがない様にしている。また逆に磁極中心側の凹字形状空隙３ａの端部３ａ’側の空隙幅は、磁極極間側の端部３ａ’’側の空隙幅より狭く設定することにより端部３ａ’側の空隙を介して磁極中心側に磁束が段階的に流れるようにするためである。尚、凸字形状回転子鉄心６を凹字形状空隙３ａの端部３ａ’側の空隙をなくして磁極中心側の回転子鉄心１と接続した状態にしてしまうと磁束が大きく流れ過ぎて電動機性能を悪化させることとなる。
【００１９】
また別の効果として、この凸字形状回転子鉄心６部分を設けることにより固定子からの磁束の一部が、一旦凸字形状回転子鉄心６に流れ、更に固定子の歯端部８に戻ることにより大きな磁束を急激に流すことなく段階的に磁束を流すことができ前記方法と併用していることにより、より良い効果を得ることは言うまでもない。
【００２０】
従って、この凹字形状収容孔２ａの端部に凹字形状空隙３ａを設けることにより凸字形状回転子鉄心６に意識的に磁束を流し、急激な磁束の疎密が発生しないようにしているため電動機の性能を維持させコギングトルクに起因する音、振動を低減することができる。
【００２１】
また、この凹字形状空隙３ａの凸字形状回転子鉄心６があることによって、凹字形状空隙３ａと回転子外周との間の継鉄部分の幅が幅広となり継鉄部分の強度を上げることが可能となる。従って、回転子製作時の取り扱い等により回転子外周が変形することがなくなり、特に大型化された電動機の回転子の空隙部と回転子外周との間の継鉄部分の幅が細長く形成されるものにおいては、継鉄部分の幅が幅広となるため強度が上がり回転子製作時の取り扱いが容易になる。
本実施例における固定子外径は好ましくはφ１８０〜φ１２０、内径はφ１１０〜φ６０で、電動機の定格出力は好ましくは１馬力〜５馬力程度のものに適用することにより顕著な効果を得ることができる。
【００２２】
また、別の実施例を図３で説明する。尚、図３以降で説明する回転子は図１及び図２に用いた回転子の構成要素と同様のものについては同じ記号を付して説明を省略する。図３には、回転子外周に伸びる永久磁石４ａが埋め込まれた凹字形状収容孔２ａの端部と、凹字形状収容孔２ａと回転子外周との間に設けた凹字形状空隙３ａが連結されて１つの収容孔として形成されている。これにより、凹字形状収容孔２ａと凹字形状空隙３ａとの間に設けられた回転子鉄心１の継鉄部がなくなり、磁極中心に向かう永久磁石４ａからの磁束を漏らすことなく有効に磁極中心に集中させることができる。尚、図１及び図２で説明した凹字形状収容孔２ａと凹字形状空隙３ａとの間の回転子鉄心１の継鉄部は、回転子鉄心１が打ち抜き可能な限り幅狭とすることは説明をするまでもない。
【００２３】
また、別の実施例を図４で説明する。図４には、回転子鉄心１の凹字形状収容孔２ａの端部に凹字形状空隙３ａを備えた永久磁石形回転子を積厚方向に２分割し積層し、周方向に所定の角度分ずらした回転子である。尚、回転子を積厚方向に２分割した場合、上方の永久磁石４ａが挿入された凹字形状収容孔２ａの端部に凹字形状空隙３ａを備えたものを実線で示し、所定の角度分ずらした下方の永久磁石４ｂが挿入された凹字形状収容孔２ｂの端部に凹字形状空隙３ｂを備えたものを破線で示している。然るに、凹字形状空隙３ａの凸字形状回転子鉄心６が回転子周方向に所定の角度分ずらした回転子とすることによって、段階的に凸字形状回転子鉄心６に磁束が流出入することになり回転子の磁極間部分で発生するコギングトルクに起因する音、振動を低減することが可能となる。
【００２４】
この場合、凸字形状回転子鉄心６を所定の角度分ずらした場合、好ましくは回転子周方向で重なり合わないようにすることが望ましい。これは、本来固定子の歯端部８から回転子に入り固定子の歯端部８へ磁束を逃がす磁路を形成しなくてはならないが、積層された凸字形状回転子鉄心６が重なり合っていると、回転子鉄心１の軸方向に磁束が逃げるため大幅な性能低下に繋がるからである。
【００２５】
また、図５には図４と同様に、回転子鉄心１の凹字形状収容孔２ａの端部に凹字形状空隙３ａを備えた永久磁石形回転子であり、図４のものとは異なり永久磁石４ａが挿入されている凹字形状収容孔２ａはずれることなく配置されており、凹字形状空隙部３ａのみが回転子の周方向に所定の角度分ずれて配置されている。尚、前記同様、回転子は積厚方向に２分割した場合を示しており、上方の永久磁石４ａが挿入された凹字形状収容孔２ａの端部に凹字形状空隙３ａを備えたものを実線で示し、下方の所定の角度分ずらした凹字形状空隙３ｃのみを破線で示している。
【００２６】
この場合、凹字形状空隙３ａは、凹字形状空隙３ａの形状を変えることなく回転子の周方向に所定の角度分ずらしても良く、また凹字形状空隙３ａの空隙を磁極中心側に伸ばしても良い。前者においては凹字形状空隙３ａの幅に凹字形状空隙３ｃの空隙の一部が必ず重なるように設定することが好ましい。仮に、凹字形状空隙３ａの空隙と凹字形状空隙３ｃの空隙が重ならないように回転子を周方向にずらすと、この空隙の重なりのない部分において磁束が大きく漏れることになり電動機の性能を悪化させることとなる。また、後者においては、図１及び図２において説明した磁極中心側への段階的な磁束の流れが、凹字形状空隙３ａの磁極中心側３ａ’の空隙を介してであったが、この場合凹字形状空隙３ａの底部、つまり凹字形状収容孔２ａの端部側の空隙から段階的に磁束が流れることとなる。従って、この場合においては磁極極間側の凹字形状空隙３ａ’’の幅より狭く設定するのは凹字形状空隙３ａの底部の空隙部となる。前者及び後者ともに凹字形状空隙３ａの凸字形状回転子鉄心６は積厚方向に重ならない様にすることが好ましい。
【００２７】
また、図４では回転子鉄心１を積層方向に２分割して積層している関係上凹字形状収容孔２ａに挿入される永久磁石４ａは、１つの磁極で見た場合、回転子積層方向に６枚挿入することとなるが、図５に示したように凹字形状収容孔２ａを回転子の周方向にずらすことがないため３枚の永久磁石４ａを挿入するだけでよい。従って、回転子鉄心１に永久磁石４ａを挿入する作業を簡略化することができる。また、当然ではあるが、永久磁石４ａの使用枚数が減るため材料の加工コストも低減することが可能となる。尚、図４及図５に示した実施例は、其々凹字形状収容孔２ａ、２ｂが凹字形状空隙部３ａ、３ｂもしくは３ｃと連結されていなくても、連結されていても同様の効果が得られる。
【００２８】
また、図６では、図４及び図５で説明した様に回転子の周方向に所定の角度分ずらした回転子のずれ角度について、回転子積厚が上下に２分割された回転子を用いて説明する。固定子の巻線が挿入される固定子のスロットピッチに対して、凹字形状収容孔２ａの端部に設けた凹字形状空隙部３ａの凸字形状回転子鉄心６のずれ角を１／２ピッチずらすことにより回転子に生じるコギングトルクを低減することができる。
【００２９】
図６で示した回転子のコギングトルクを低減する手法について図７を用いて説明する。図７の（ａ）には、縦軸がコギングトルクの脈動の周期Ｔを表し、横軸は回転子の回転角度θを示している。上方の回転子積層部分で発生するコギングトルクをＴθ１として、下方の回転子積層部分で発生するコギングトルクをＴθ２とすると、上方の回転子積層部分で発生するコギングトルクＴθ１に対して下方の回転子積層部分で発生するコギングトルクＴθ２を固定子スロットピッチ１／２周期に相当する機械角分を相対的にずらすことにより、上方の回転子積層部分で発生するコギングトルクＴθ１を１／２周期ずれた逆位相のコギングトルクＴθ２でコギングトルクを打ち消すことができる。尚、図７の（ｂ）には上方と下方の回転子積層部分で発生したコギングトルクによって打ち消された状態を示している。
【００３０】
尚、図６及び図７では、回転子積厚を２分割されている場合について説明したが、回転子積厚を偶数個で分割することにより図６及び図７と同様の方法でコギングトルクを低減することが可能である。
【００３１】
また、図１及至図７に示した永久磁石４ａ、４ｂを挿入した凹字形状収容孔２ａ、２ｂの端部と回転子外周との間に凹字形状空隙３ａ、３ｂ、もしくは３ｃを設けた永久磁石埋め込み形回転子を、固定子の歯部に直接巻線が巻かれた集中巻方式の固定子と対向配置させた電動機とすることによってコギングトルクに起因する音、振動を低減することができる。特に、固定子のスロット数が少ない６スロット、９スロット、１２スロット等において、その効果は良好である。
【００３２】
また、図１及び図７に示した凹字形状空隙３ａ、３ｂもしくは３ｃは、磁極中心側を伸ばす場合、凸字形状回転子鉄心６は、連続した凸字形状であっても良く、また、不連続の凸字形状であっても良い。従って、凹字形状空隙３ａは、凹字のみならずＥ字形状、櫛形状でも良く本発明の主旨を逸脱しない範囲で適宜適用することにより達成することができる。
【００３３】
以上の様に、凹字形状収容孔２ａに永久磁石４ａを埋め込み、この凹字形状収容孔２ａの端部に凹字形状空隙３ａを設けた永久磁石回転子や、前記回転子において積厚方向に複数に分割され相対的に其々が所定の角度分ずれている回転子を説明してきたが、この永久磁石埋め込み回転子を、例えばエアコン用または冷蔵庫用の駆動源となる密閉圧縮機内に組み込まれた後に固定子の巻線を利用して回転子に着磁を施す場合、通常、凹字形状収容孔２ａの端部に凹字形状空隙３ａを設けていない状態では、所定の角度分ずれた回転子積層部分において固定子の磁極極間位置と回転子の磁極極間位置とが異なるため、凹字形状収容孔２ａの磁極極間側の背面より逆の着磁磁界が係るため、回転子に埋め込まれた永久磁石４ａを着磁することができなくなる。従って、密閉圧縮機に組み込まれた固定子を利用して回転子に着磁を施すことができなかった。
【００３４】
しかしながら、図１及至図７で説明したような凹字形状収容孔２ａ、２ｂと回転子外周との間に凹字形状空隙３ａ、３ｂ、もしくは３ｃを設けることにより、この凹字形状空隙３ａ、３ｂ、もしくは３ｃの側端部を凹字形状収容孔２ａ、２ｂの背面の磁極極間側まで張り出すことにより固定子から回転子に流れ込む逆の着磁磁界を防ぐことができるため密閉圧縮機に組み込まれた固定子により極間がずれることなく回転子を着磁することができる。
【００３５】
【発明の効果】
固定子の内部に回転子を有する内転型の電動機であって、回転子の軸孔を中心として回転子外周まで伸びる凹字形状収容孔を備え、この凹字形状収容孔に永久磁石が埋め込まれおり、凹字形状収容孔の端部と回転子外周の間には空隙を有し、この空隙は、回転子外周から回転子鉄心の一部が回転子内径方向に凸字状に突出する凸字形状回転子鉄心を形成する凹字形状とすることにより回転子鉄心からの磁束は固定子鉄心を介して再び回転子鉄心に入る際、急激な磁束の変化が発生することがなく段階的に磁束の流出入を変化させることとなり電動機の性能を維持させコギングトルクに起因する音、振動を低減することができる。特に電動機が高負荷で運転されるものや大型化されたものでは有利である。
【００３６】
また、凹字形状空隙があることにより永久磁石による磁束を漏れることなく磁極中心に集中させることができ、またリラクタンストルクの磁路を確実に確保することができるため電動機の総合トルクを大幅に上げることができる。
【００３７】
また、この凹字形状の空隙の凸字形状回転子鉄心部があることによって、凹字形状の空隙と回転子外周との間の継鉄部分を幅広とすることができ強度を上げることが可能となる。従って、特に大型化された電動機でも凹字形状の空隙とすることによって磁束を漏らすことなく凹字形状の空隙と回転子外周の間の細長い継鉄部分を幅広にすることができ回転子製作時の取り扱い等による変形が少なくなり品質面が向上し、電動機の性能低下やコギングトルクに起因する音、振動が発生することもなくなる。
【００３８】
また、この凹字形状空隙と永久磁石を埋め込むための凹字形状収容孔とを連結することによって永久磁石が発生する磁束を漏らすことがないため電動機の性能を向上させることができる。
【００３９】
また、この回転子が積厚方向に複数に分割され凹字形状空隙が回転子の周方向に所定の角度分ずらした電動機の回転子とすることによって、段階的に凸字形状の回転子鉄心に磁束が流出入することになり回転子の磁極間部分で発生するコギングトルクに起因する音、振動を低減することが可能になる。また、永久磁石が挿入される凹字形状収容孔をずらすことなく、凹字形状空隙のみ回転子の周方向に所定の角度分ずらすことによって、永久磁石の使用枚数を減らすことができるため作業効率が上がり、材料費等も低減することが可能になる。また、凹字形状空隙を磁極中心に向かい所定の角度分伸ばすことによっても前記と同様の効果が得ることができる。
【００４０】
また、回転子の積厚方向に複数に分割された回転子の凹字形状空隙を、回転子の周方向に固定子のスロットピッチの１／２の角度分を相対的にずらすことにより、回転子磁極極間部で発生するコギングトルクの脈動の周期が互いに逆位相となるためコギングトルクの脈動を打ち消すことができ音、振動等低減することができる。
【００４１】
また、この方法による回転子を固定子の歯部に直接巻線が巻かれた集中巻方式の固定子に使用することによってコギングトルクに起因する音、振動を低減することができる。
【００４２】
また、回転子の軸孔を中心として回転子外周まで伸びる凹字形状収容孔を備え、凹字形状収容孔に永久磁石が埋め込まれおり、凹字形状収容孔の端部と回転子外周の間には空隙を有し、この空隙は、回転子外周から回転子鉄心の一部が回転子内径方向に凸字状に突出する凸字形状回転子鉄心を形成する凹字形状とした電動機の回転子において、前記回転子が積厚方向に複数に分割され、凹字形状空隙が回転子の周方向に所定の角度分ずれている回転子とすることにより磁極極間位置が異なる回転子でも、ハウジングに組み込まれた後に固定子を着磁ヨークとして着磁をすることができる。
例えば、固定子と回転子を冷蔵庫やエアコン等の駆動源とする密閉圧縮機内に組み込んだ後に、固定子を着磁ヨークとして回転子を着磁することが可能となる。
【００４３】
【図面の簡単な説明】
【図１】本発明の実施例を示す回転子の横断面図。
【図２】図１における磁束の流れを示す図である。
【図３】別の実施例を示す回転子の横断面図。
【図４】別の実施例を示す回転子の横断面図。
【図５】別の実施例を示す回転子の横断面図。
【図６】別の実施例を示す固定子と回転子の部分横断面図。
【図７】図６に示した回転子構造のコギングトルクの脈動周期。
【図８】従来例を示す回転子の横断面図。
【符号の説明】
１…回転子鉄心、２，２ａ，２ｂ…凹字形状収容孔、３…空隙、３ａ，３ｂ，３ｃ…凹字形状空隙、３ａ’，３ａ’’，…凹字形状空隙の側端部、４，４ａ，４ｂ…永久磁石、５…軸孔、６…凸字形状回転子鉄心、７…固定子鉄心、８…歯端部、９…カシメピン。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotor of an electric motor used in industrial equipment, office equipment, and home appliances.
[0002]
[Prior art]
In recent years, permanent magnet type electric motors using permanent magnets are generally used in electric motors used for industrial equipment, office equipment, and household appliances. For rotors of permanent magnet type electric motors, various types of rotor structures have been proposed that utilize a reluctance torque by securing a magnetic flux path inside the rotor due to the amount of magnetic flux of the permanent magnet. Conventionally, in order to improve the motor performance, the permanent magnet embedded in the rotor has been improved in performance or increased in the amount of use, but there are limitations on the cost and the structure of the rotor.
[0003]
In this problem, a rotor as shown in FIG. 8 has been proposed. FIG. 8 shows an embedded permanent magnet rotor used in a three-phase four-pole motor, and the adjacent permanent magnets 4 are arranged so as to have different polarities. In the rotor core 1 with the rotor shaft hole 5 as the center, a receiving hole 2 for inserting the permanent magnet 4 is arranged in an arc shape opposite to the outer periphery of the rotor. A space 3 is provided in the vicinity of the outer periphery of the rotor of the arc-shaped accommodation hole 2. The gap 3 is formed large in the direction of the magnetic pole center in order to concentrate the magnetic flux generated by the permanent magnet 4 in the d-axis direction shown in the figure. As a result, the magnetic flux is concentrated at the center of the magnetic pole, and the magnetic flux in the non-energized section viewed from the motor control side can be concentrated in the energized section. ing.
[0004]
[Problems to be solved by the invention]
However, in such a motor, the magnetic flux can be concentrated and the performance of the motor can be improved, but the difference in the flow of the magnetic flux between the poles becomes very large, and sound, vibration, etc. due to the cogging torque of the motor are generated. Yes.
[0005]
In particular, when the output of the motor is large and overloaded, noise, vibration, and the like due to the cogging torque of the motor become noticeable.
[0006]
Further, the gap 3 provided in the vicinity of the outer periphery of the rotor of the receiving hole 2 into which the permanent magnet 4 is inserted into the rotor core 1 in the electric motor in a motor is formed larger toward the magnetic pole center by concentrating the magnetic flux at the magnetic pole center. In addition, the width of the yoke portion between the gap 3 and the outer periphery of the rotor is very narrow and narrow so that the magnetic flux does not leak, so that the strength is insufficient. The outer periphery of the rotor of the iron part is deformed and the gap with the inner diameter of the stator is not uniform, which is an important problem in terms of quality. This manifests itself as noise, vibration, etc. due to the motor performance degradation and motor cogging torque.
[0007]
[Means for Solving the Problems]
An internal rotation type motor having a rotor inside a stator, the rotor having a concave-shaped accommodation hole in which a permanent magnet is embedded, and having a concave-shaped accommodation hole centered on the shaft hole of the rotor The end extends to the outer periphery of the rotor, and there is a gap between the end of the concave housing hole and the outer periphery of the rotor, and this gap is a part of the rotor core from the outer periphery of the rotor. There can be achieved by the rotor of the concave shape gap between the electric motor which forms a convex-shape rotor iron core that protrudes in a convex shape in the rotor radially inwards.
[0008]
Moreover, it can achieve by connecting this concave-shaped space | gap and the concave-shaped accommodation hole for embedding a permanent magnet.
[0009]
In addition, the rotor is divided into a plurality of parts in the stacking direction, and the concave-shaped accommodation hole and the concave-shaped gap into which the permanent magnet is inserted are shifted by a predetermined angle in the circumferential direction of the rotor. Can be achieved.
[0010]
In addition, this rotor is divided into a plurality in the stacking direction, and only the concave air gap is shifted by a predetermined angle in the circumferential direction of the rotor without shifting the concave housing hole into which the permanent magnet is inserted. This can be achieved by using a rotor of an electric motor. The same effect can be obtained by extending the concave air gap toward the center of the magnetic pole by a predetermined angle.
[0011]
Moreover, it can achieve by making the rotor of an electric motor into which the concave-shaped space | gap has shifted | deviated by 1/2 angle of the slot pitch of the stator in the circumferential direction of the rotor.
[0012]
In addition, this can be achieved by using a rotor of an electric motor disposed opposite to a concentrated winding type stator in which a winding is directly wound around a tooth portion of the stator.
[0013]
Further, the rotor includes a concave-shaped accommodation hole in which a permanent magnet is embedded, and an end of the concave-shaped accommodation hole is formed to extend to the outer periphery of the rotor around the shaft hole of the rotor. There is a gap between the end of the concave housing hole and the outer periphery of the rotor, and this gap is a convex character in which a part of the rotor core protrudes in a convex shape from the outer periphery of the rotor toward the inner diameter of the rotor. In the rotor of an electric motor having a concave-shaped gap that forms a shaped rotor core, the rotor is divided into a plurality in the stacking direction, and the concave-shaped gap is shifted by a predetermined angle in the circumferential direction of the rotor. Let the rotor be a method of magnetizing a rotor that is magnetized with the stator as a magnetizing yoke after being incorporated in the housing.
For example, after a stator and a rotor are incorporated in a hermetic compressor such as a refrigerator or an air conditioner, the rotor can be magnetized using the stator as a magnetizing yoke.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. FIG. 1 has a concave-shaped accommodation hole 2a for inserting a permanent magnet 4a inside a rotor core 1, and is different from the permanent magnet 4a inserted in the adjacent concave-shaped accommodation hole 2a and has four poles. Forming. A flat plate permanent magnet in which the permanent magnet 4a is divided into a central bottom portion and a concave shape accommodation hole side portion is inserted into the concave shape accommodation hole 2a. Between the concave shape accommodation hole 2a and the outer periphery of the rotor, there is a concave shape gap 3a. The bottom part of the concave-shaped gap 3a is arranged so as to face the end part of the concave-shaped accommodation hole 2a, and the end part of the concave-shaped gap 3a is arranged so as to face the rotor outer periphery. Therefore, when viewed from the outer diameter of the rotor, a convex rotor core 6 is formed in which a part of the rotor core 1 protrudes in a convex shape in the inner diameter direction of the rotor.
[0015]
The width between the end 3a 'of the concave air gap 3a located on the rotor magnetic pole center side and the outer periphery of the rotor is preferably about 0.35 mm to 2.0 mm, and between the rotor and the stator. So as to saturate the generated magnetic flux. The magnetic flux density may be about 2.0T. That is, the magnetic flux generated by the permanent magnet 4a embedded in the concave-shaped receiving hole 2a for concentrating the magnetic flux at the magnetic pole center is forced to be directed toward the magnetic pole center by the end 3a ′ of the concave-shaped gap 3a. Magnetic flux leakage is prevented. As a result, the magnet torque contributing to the performance of the electric motor can be increased, and the total torque can be increased.
[0016]
The width between the end 3a '' of the concave-shaped gap 3a located on the rotor magnetic pole side and the outer periphery of the rotor is the end of the concave-shaped gap 3a located on the magnetic pole center side described above. Similarly to the width 3a ′, the thickness is preferably about 0.35 mm to 2.0 mm so that the magnetic flux generated between the rotor and the stator is saturated. In this case as well, the magnetic flux density may be about 2.0T, and the end 3a '' of the concave air gap 3a extends beyond the width of the concave housing hole 2a to the pole pole part. As a result, the reluctance torque can be concentrated in the vicinity of the rotor outer periphery of the magnetic path of the rotor core 1 located between the concave housing hole 2a embedded with the permanent magnet 4a and the rotor shaft hole 5. Can be raised.
[0017]
Further, the convex rotor core 6 in the center of the concave-shaped gap 3a is wider than the width between the end portions 3a ′ and 3a ″ of the concave-shaped gap 3a and the outer periphery of the rotor. By having the convex rotor core 6 wider than the end portions 3a ′ and 3a ″ of the concave gap 3a, the magnetic torque center is concentrated from the magnetic pole pole portion where the reluctance torque is concentrated. The magnetic flux can be changed and flowed in a stepwise manner.
[0018]
This embodiment will be described using the stator core 7 and the rotor core 1 in FIG. Although not shown, a stator winding is mounted in a slot of the stator core 7. The magnetic flux from the stator core 7 enters the stator core 7 again via the rotor core 1. The arrows in the figure indicate the flow of magnetic flux. This magnetic flux appears as a very large magnetic flux density between the rotor and the stator when the electric motor is operated at a high load or is enlarged. Therefore, by providing the convex rotor core 6, the magnetic flux can be flowed stepwise. That is, since the magnetic flux flows to the magnetic pole center side through the concave air gap 3a, a sudden change in the magnetic flux does not occur. In this case, it is preferable that the gap width on the end 3a ″ side of the concave-shaped gap 3a on the side between the magnetic poles is set wider than the gap width on the end 3a ′ side on the magnetic pole center side. This prevents the leakage of magnetic flux to the side between the magnetic poles. Conversely, the gap width on the end 3a ′ side of the concave-shaped gap 3a on the magnetic pole center side is set to be narrower than the gap width on the end 3a ″ side on the pole pole side, so that the gap on the end 3a ′ side is set. This is because the magnetic flux flows stepwise to the magnetic pole center side. If the convex rotor core 6 is connected to the rotor core 1 on the magnetic pole center side by eliminating the gap on the end 3a ′ side of the concave gap 3a, the magnetic flux will flow too much and the motor performance. Will worsen.
[0019]
As another effect, by providing the convex-shaped rotor core 6 portion, a part of the magnetic flux from the stator once flows into the convex-shaped rotor core 6 and then returns to the tooth end portion 8 of the stator. Needless to say, a magnetic flux can be caused to flow stepwise without causing a large magnetic flux to flow, and a better effect can be obtained by using the method together.
[0020]
Therefore, by providing the concave-shaped gap 3a at the end of the concave-shaped accommodation hole 2a, a magnetic flux is consciously flowed through the convex-shaped rotor core 6 so that sudden magnetic flux density does not occur. The performance of the electric motor can be maintained and the noise and vibration caused by the cogging torque can be reduced.
[0021]
Moreover, the presence of the convex-shaped rotor core 6 of the concave-shaped gap 3a increases the width of the yoke portion between the concave-shaped gap 3a and the outer periphery of the rotor, thereby increasing the strength of the yoke portion. Is possible. Accordingly, the outer periphery of the rotor is not deformed due to handling at the time of manufacture of the rotor, and the width of the yoke portion between the rotor gap and the outer periphery of the rotor, which is particularly large, is elongated. In a thing, since the width of a yoke part becomes wide, intensity | strength increases and the handling at the time of rotor manufacture becomes easy.
In this embodiment, the outer diameter of the stator is preferably φ180 to φ120, the inner diameter is φ110 to φ60, and the rated output of the motor is preferably about 1 to 5 horsepower, so that a remarkable effect can be obtained. .
[0022]
Another embodiment will be described with reference to FIG. Note that the rotors described in FIG. 3 and subsequent figures are the same as those of the rotors used in FIGS. 1 and 2 and are not described. In FIG. 3, an end of the concave-shaped accommodation hole 2 a embedded with a permanent magnet 4 a extending on the outer periphery of the rotor and a concave-shaped gap 3 a provided between the concave-shaped accommodation hole 2 a and the outer periphery of the rotor are shown. It is connected and formed as one accommodation hole. Thereby, the yoke part of the rotor core 1 provided between the concave-shaped accommodation hole 2a and the concave-shaped gap 3a is eliminated, and the magnetic pole can be effectively made without leaking the magnetic flux from the permanent magnet 4a toward the magnetic pole center. Can be centered. The yoke portion of the rotor core 1 between the concave-shaped accommodation hole 2a and the concave-shaped gap 3a described in FIGS. 1 and 2 should be as narrow as possible so that the rotor core 1 can be punched. Needless to explain.
[0023]
Another embodiment will be described with reference to FIG. In FIG. 4, a permanent magnet type rotor having a concave-shaped gap 3a at the end of the concave-shaped accommodation hole 2a of the rotor core 1 is divided into two in the stacking direction and laminated, and a predetermined angle in the circumferential direction. It is a rotor that is shifted by a minute. In addition, when the rotor is divided into two in the stacking direction, the one provided with the concave-shaped air gap 3a at the end of the concave-shaped accommodating hole 2a into which the upper permanent magnet 4a is inserted is indicated by a solid line, and a predetermined angle A broken line is shown with a concave-shaped gap 3b at the end of the concave-shaped accommodation hole 2b into which the lower permanent magnet 4b is inserted. However, when the convex rotor core 6 of the concave gap 3a is a rotor shifted by a predetermined angle in the circumferential direction of the rotor, the magnetic flux flows into and out of the convex rotor core 6 step by step. As a result, it is possible to reduce the sound and vibration caused by the cogging torque generated in the portion between the magnetic poles of the rotor.
[0024]
In this case, when the convex rotor core 6 is shifted by a predetermined angle, it is desirable that the convex rotor cores 6 should not overlap each other in the rotor circumferential direction. This is because a magnetic path that essentially enters the rotor from the tooth end 8 of the stator and releases the magnetic flux to the tooth end 8 of the stator must be formed, but the stacked convex-shaped rotor cores 6 overlap. This is because the magnetic flux escapes in the axial direction of the rotor core 1, leading to a significant performance degradation.
[0025]
Further, FIG. 5 shows a permanent magnet type rotor having a concave-shaped air gap 3a at the end of the concave-shaped accommodation hole 2a of the rotor core 1, similar to FIG. The concave-shaped accommodation holes 2a into which the permanent magnets 4a are inserted are arranged without being displaced, and only the concave-shaped gaps 3a are arranged at a predetermined angle in the circumferential direction of the rotor. As described above, the rotor is shown in a case where the rotor is divided into two in the stacking direction, and the rotor is provided with a concave-shaped gap 3a at the end of the concave-shaped receiving hole 2a into which the upper permanent magnet 4a is inserted. Only the concave-shaped gap 3c which is indicated by a solid line and shifted by a predetermined angle below is indicated by a broken line.
[0026]
In this case, the concave-shaped gap 3a may be shifted by a predetermined angle in the circumferential direction of the rotor without changing the shape of the concave-shaped gap 3a, and the gap of the concave-shaped gap 3a is extended to the magnetic pole center side. May be. In the former, it is preferable to set so that a part of the gap of the concave-shaped gap 3c necessarily overlaps the width of the concave-shaped gap 3a. If the rotor is shifted in the circumferential direction so that the gap of the concave-shaped gap 3a and the gap of the concave-shaped gap 3c do not overlap, the magnetic flux leaks greatly in the portion where the gap does not overlap, and the performance of the motor is reduced. It will make it worse. In the latter case, the gradual flow of magnetic flux toward the magnetic pole center described with reference to FIGS. 1 and 2 was through the gap on the magnetic pole center side 3a ′ of the concave-shaped gap 3a. Magnetic flux flows in a stepwise manner from the bottom of the concave-shaped gap 3a, that is, the gap on the end side of the concave-shaped receiving hole 2a. Therefore, in this case, it is the gap at the bottom of the concave-shaped gap 3a that is set narrower than the width of the concave-shaped gap 3a '' between the poles. In both the former and the latter, it is preferable that the convex rotor core 6 of the concave cavity 3a does not overlap in the stacking direction.
[0027]
Further, in FIG. 4, the rotor core 1 is divided into two in the stacking direction, and the permanent magnet 4 a inserted into the concave-shaped accommodation hole 2 a is stacked in the stacking direction. However, as shown in FIG. 5, it is only necessary to insert the three permanent magnets 4a because the concave housing holes 2a are not shifted in the circumferential direction of the rotor. Therefore, the operation of inserting the permanent magnet 4a into the rotor core 1 can be simplified. Of course, since the number of permanent magnets 4a used is reduced, the processing cost of the material can be reduced. Note that the embodiment shown in FIG. 4 and FIG. 5 is the same regardless of whether or not the concave-shaped receiving holes 2a and 2b are connected to the concave-shaped gaps 3a, 3b, or 3c. An effect is obtained.
[0028]
Further, in FIG. 6, as described with reference to FIGS. 4 and 5, a rotor whose rotor stack thickness is vertically divided into two is used for the rotor shift angle shifted by a predetermined angle in the circumferential direction of the rotor. I will explain. With respect to the slot pitch of the stator into which the stator winding is inserted, the deviation angle of the convex rotor core 6 of the concave cavity 3a provided at the end of the concave housing hole 2a is 1 /. Cogging torque generated in the rotor can be reduced by shifting the pitch by two pitches.
[0029]
A method for reducing the cogging torque of the rotor shown in FIG. 6 will be described with reference to FIG. In FIG. 7A, the vertical axis represents the pulsation period T of the cogging torque, and the horizontal axis represents the rotation angle θ of the rotor. When the cogging torque generated in the upper rotor lamination portion is Tθ1, and the cogging torque generated in the lower rotor lamination portion is Tθ2, the lower rotor with respect to the cogging torque Tθ1 generated in the upper rotor lamination portion. The cogging torque Tθ1 generated in the upper rotor laminated portion is shifted by ½ period by relatively shifting the cogging torque Tθ2 generated in the laminated portion by the mechanical angle corresponding to the stator slot pitch ½ period. The cogging torque can be canceled by the anti-phase cogging torque Tθ2. FIG. 7 (b) shows a state in which it is canceled out by the cogging torque generated in the upper and lower rotor lamination portions.
[0030]
6 and 7, the rotor product thickness is divided into two parts. However, by dividing the rotor product thickness into an even number, the cogging torque is obtained in the same manner as in FIGS. It is possible to reduce.
[0031]
Also, a concave-shaped air gap 3a, 3b, or 3c is provided between the end of the concave-shaped accommodation hole 2a, 2b into which the permanent magnets 4a, 4b shown in FIGS. 1 to 7 are inserted and the outer periphery of the rotor. Noise and vibration caused by cogging torque can be reduced by using a permanent magnet embedded rotor as an electric motor that is placed opposite to a concentrated winding type stator in which windings are wound directly on the teeth of the stator. it can. In particular, the effect is good in 6 slots, 9 slots, 12 slots, etc. with a small number of stator slots.
[0032]
Moreover, when the concave-shaped air gap 3a, 3b or 3c shown in FIG. 1 and FIG. 7 extends in the magnetic pole center side, the convex-shaped rotor core 6 may be a continuous convex-shaped shape, It may be a discontinuous convex shape. Accordingly, the concave-shaped gap 3a may be not only a concave shape but also an E-shape or a comb shape, and can be achieved by applying as appropriate without departing from the gist of the present invention.
[0033]
As described above, a permanent magnet rotor in which the permanent magnet 4a is embedded in the concave-shaped housing hole 2a and the concave-shaped space 3a is provided at the end of the concave-shaped housing hole 2a, In the above description, the rotor is divided into a plurality of parts and each of them is relatively shifted by a predetermined angle. This embedded permanent magnet rotor is incorporated into a hermetic compressor serving as a drive source for an air conditioner or a refrigerator, for example. When the rotor is magnetized using the winding of the stator after this, usually, when the concave-shaped gap 3a is not provided at the end of the concave-shaped receiving hole 2a, the predetermined angle is shifted. Since the position between the magnetic pole poles of the stator is different from the position between the magnetic pole poles of the rotor in the laminated rotor portion, a reverse magnetizing magnetic field is applied from the back side of the concave housing hole 2a between the magnetic pole poles. The permanent magnet 4a embedded in the child can be magnetized Kunar. Therefore, the rotor could not be magnetized using the stator incorporated in the hermetic compressor.
[0034]
However, by providing a concave-shaped gap 3a, 3b, or 3c between the concave-shaped accommodation holes 2a, 2b and the outer periphery of the rotor as described in FIGS. 1 to 7, the concave-shaped gap 3a, Since the side magnet 3b or 3c is extended to the side between the pole poles on the back surface of the concave housing holes 2a and 2b, a reverse magnetizing magnetic field flowing from the stator to the rotor can be prevented, so that the hermetic compressor The rotor can be magnetized without a gap between the poles due to the stator incorporated in.
[0035]
【The invention's effect】
An internal rotation type electric motor having a rotor inside the stator, and having a concave-shaped accommodation hole extending to the outer periphery of the rotor around the rotor shaft hole, and a permanent magnet is embedded in the concave-shaped accommodation hole There is a gap between the end of the concave housing hole and the outer periphery of the rotor, and a part of the rotor core protrudes in a convex shape in the inner diameter direction of the rotor from the outer periphery of the rotor. By adopting the concave shape that forms the convex-shaped rotor core, the magnetic flux from the rotor core is stepped without sudden change of magnetic flux when it enters the rotor core again through the stator core. Therefore, the flow of the magnetic flux is changed, so that the performance of the motor can be maintained and the sound and vibration caused by the cogging torque can be reduced. In particular, it is advantageous when the motor is operated at a high load or when the motor is enlarged.
[0036]
In addition, the presence of the concave-shaped air gap allows the magnetic flux generated by the permanent magnet to be concentrated at the center of the magnetic pole without leaking, and the magnetic path of the reluctance torque can be reliably ensured, greatly increasing the overall torque of the motor. be able to.
[0037]
In addition, the presence of the convex rotor core of the concave shape allows the yoke portion between the concave shape and the outer periphery of the rotor to be widened, thereby increasing the strength. It becomes. Therefore, even in a large-sized electric motor, the elongated yoke part between the concave-shaped gap and the outer periphery of the rotor can be widened without leaking magnetic flux by making the concave-shaped gap. The deformation due to the handling of the motor is reduced, the quality is improved, and the noise and vibration due to the motor performance degradation and the cogging torque are not generated.
[0038]
Further, by connecting the concave-shaped gap and the concave-shaped accommodation hole for embedding the permanent magnet, the magnetic flux generated by the permanent magnet is not leaked, so that the performance of the electric motor can be improved.
[0039]
In addition, the rotor is divided into a plurality of portions in the stacking direction, and the concave-shaped air gap is shifted by a predetermined angle in the circumferential direction of the rotor. Thus, the magnetic flux flows in and out, and it is possible to reduce the sound and vibration caused by the cogging torque generated in the portion between the magnetic poles of the rotor. In addition, the number of permanent magnets used can be reduced by shifting only the concave air gap by a predetermined angle in the circumferential direction of the rotor without shifting the concave housing hole into which the permanent magnet is inserted. As a result, material costs and the like can be reduced. Also, the same effect as described above can be obtained by extending the concave-shaped gap toward the center of the magnetic pole by a predetermined angle.
[0040]
In addition, the rotor-shaped concave air gap divided into a plurality of rotors in the stacking direction can be rotated by relatively shifting an angle of 1/2 of the stator slot pitch in the circumferential direction of the rotor. Since the period of cogging torque pulsation generated between the poles of the child magnetic poles is opposite to each other, the pulsation of cogging torque can be canceled and noise, vibration, etc. can be reduced.
[0041]
Further, by using the rotor according to this method for a concentrated winding type stator in which a winding is directly wound around the teeth of the stator, it is possible to reduce noise and vibration caused by cogging torque.
[0042]
Also, it has a concave-shaped accommodation hole that extends to the outer periphery of the rotor around the shaft hole of the rotor, and a permanent magnet is embedded in the concave-shaped accommodation hole, between the end of the concave-shaped accommodation hole and the outer periphery of the rotor has a gap, this gap is, the rotation part from the rotor outer periphery of the rotor iron core of an electric motor and a concave shape to form a convex shape rotor iron core that protrudes in a convex shape in the rotor radially inwards In the rotor, the rotor is divided into a plurality of parts in the stacking direction, and the rotor having a different position between the magnetic poles by making the concave-shaped gap a predetermined angle in the circumferential direction of the rotor, After being incorporated in the housing, the stator can be magnetized using the magnetized yoke.
For example, after the stator and the rotor are incorporated into a hermetic compressor using a drive source such as a refrigerator or an air conditioner, the rotor can be magnetized using the stator as a magnetizing yoke.
[0043]
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a rotor showing an embodiment of the present invention.
FIG. 2 is a diagram showing the flow of magnetic flux in FIG.
FIG. 3 is a cross-sectional view of a rotor showing another embodiment.
FIG. 4 is a cross-sectional view of a rotor showing another embodiment.
FIG. 5 is a cross-sectional view of a rotor showing another embodiment.
FIG. 6 is a partial cross-sectional view of a stator and a rotor showing another embodiment.
7 is a pulsation period of cogging torque of the rotor structure shown in FIG.
FIG. 8 is a transverse sectional view of a rotor showing a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Rotor core, 2, 2a, 2b ... Concave-shaped accommodation hole, 3 ... Air gap, 3a, 3b, 3c ... Concave-shaped air gap, 3a ', 3a'', ... Side edge part of concave-shaped air gap, 4, 4a, 4b ... permanent magnet, 5 ... shaft hole, 6 ... convex-shaped rotor core, 7 ... stator core, 8 ... tooth end, 9 ... caulking pin.

Claims

An internal rotation type electric motor having a rotor inside a stator, wherein the rotor has a concave shape accommodation hole in which a permanent magnet is embedded, and the concave shape is formed around the shaft hole of the rotor. end of the receiving hole is formed extending to the rotor outer periphery, has a gap between the end portion and the rotor outer circumference of the concave-shaped housing hole, the gap is rotated from the rotor periphery the rotor of the motor, wherein the part of the child core is concave shaped void to form a convex shape rotor iron core that protrudes in a convex shape in the rotor radially inwards.

The rotor of an electric motor according to claim 1, wherein the concave-shaped gap and the concave-shaped accommodation hole for embedding the permanent magnet are connected.

The rotor is divided into a plurality in the stacking direction, and the concave shape accommodation hole and the concave shape gap into which the permanent magnet is inserted are shifted by a predetermined angle in the circumferential direction of the rotor. The rotor of the electric motor according to claim 1, wherein the rotor is an electric motor.

The rotor is divided into a plurality of layers in the stacking direction, and only the concave air gap is provided at a predetermined angle in the circumferential direction of the rotor without shifting the concave housing hole into which the permanent magnet is inserted. The electric motor rotor according to claim 1, wherein the electric motor rotor is deviated.

The rotor is divided into a plurality in the stacking direction, and the concave air gap is extended by a predetermined angle toward the center of the magnetic pole without shifting the concave housing hole into which the permanent magnet is inserted. The rotor of the electric motor according to claim 1, wherein the rotor is an electric motor.

The rotor of an electric motor according to any one of claims 3 to 5, wherein the concave-shaped gap is displaced by an angle of ½ of a slot pitch of the stator in a circumferential direction of the rotor.

The motor according to any one of claims 1 to 6, wherein the rotor is an electric motor arranged opposite to a concentrated winding type stator in which a winding is directly wound around a tooth portion of the stator. Rotor.

An internal rotation type electric motor having a rotor inside a stator, wherein the rotor has a concave shape accommodation hole in which a permanent magnet is embedded, and the concave shape is formed around the shaft hole of the rotor. end of the receiving hole is formed extending to the rotor outer periphery, has a gap between the end portion and the rotor outer circumference of the concave-shaped housing hole, the gap is rotated from the rotor periphery In the rotor of an electric motor that is a concave-shaped air gap that forms a convex-shaped rotor core in which a portion of the core is protruded in a convex shape in the inner diameter direction of the rotor, the rotor is divided into a plurality in the stacking direction. 2. The rotor having the concave-shaped gap displaced by a predetermined angle in the circumferential direction of the rotor is magnetized with the stator as a magnetizing yoke after being incorporated in the housing. The rotor magnetizing method according to claim 7.

The motor rotor according to any one of claims 1 to 8, wherein the rotor is incorporated in a hermetic compressor using a drive source such as a refrigerator or an air conditioner.