JP2004088970A

JP2004088970A - Laminated core, rotating electric machine and transformer using the same

Info

Publication number: JP2004088970A
Application number: JP2002249890A
Authority: JP
Inventors: Junya Kaneda; 金田　潤也; Shigeo Amagi; 天城　滋夫; Kazumasa Ide; 井出　一正
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 2002-08-29
Filing date: 2002-08-29
Publication date: 2004-03-18

Abstract

【課題】電磁鋼板間の接着強度および電気絶縁性を確保しつつ、積層方向の熱伝導性能を改善した積層鉄心を提供する。
【解決手段】電磁鋼板を積層してなる鉄心において、電磁鋼板間に少なくとも有機物からなる接着層が存在し、有機物接着層の平均厚さが４μｍ以下であることを特徴とする。又は有機物は硬化反応前の流動性が必要とされる温度での粘度が１．０Ｐａ・ｓ以下とする。若しくは電磁鋼板の板厚が０．３５ｍｍ　以下であることを特徴とする。
【選択図】　図１Provided is a laminated iron core having improved heat conduction performance in a laminating direction while securing adhesive strength and electrical insulation between electromagnetic steel sheets.
In an iron core formed by laminating electromagnetic steel sheets, an adhesive layer made of at least an organic substance is present between the electromagnetic steel sheets, and an average thickness of the organic substance adhesive layer is 4 μm or less. Alternatively, the organic material has a viscosity of 1.0 Pa · s or less at a temperature at which fluidity is required before the curing reaction. Alternatively, the thickness of the electromagnetic steel sheet is 0.35 mm or less.
[Selection diagram] Fig. 1

Description

【０００１】
【発明の属する技術分野】
本発明は、電磁鋼板を積層してなる鉄心、それを用いる回転電機及びトランスに関する。
【０００２】
【従来の技術】
回転電機やトランスは、その鉄心が電磁鋼板を積層した積層鉄心で構成されている。これまでは、かしめ，溶接，クランプといった方法で積層されていたが、用途や構造によってはこれらの積層手法を採用できない。まず、電磁鋼板の板厚が薄い場合、たとえば０．２ｍｍ　以下となる場合や、６．５％　ケイ素鋼板のように塑性変形が困難な電磁鋼板の場合はかしめが困難である。また、周波数が高い場合や高電圧となる場合、かしめ，溶接，ボルト締めといった方法は電磁鋼板間を電気的に短絡させ、鉄損が増加したり、あるいは誘導電流により装置自身を損なう恐れがある。そこで、特許第２５７４６９８号，特許第３１４１０４３号や特開平７−２５６２０６号公報，特開平７−３０８９９０号公報，特開平８−２４７７９号公報に記載された技術のように接着樹脂で電磁鋼板を接着積層する方法が提案されている。
【０００３】
【発明が解決しようとする課題】
しかしながら回転電機等では、電磁鋼板を積層する接着強度だけでなく、積層鉄心の熱伝導性や電気絶縁性も重要な因子である。特に、小型化あるいは高出力化のためには冷却効率が良いことが重要となる。この観点で、特開平１１−１５０８９５号に積層方向の熱伝導率を向上させた積層鉄心とその製造方法が提案されている。しかし、この方法では樹脂層の薄い鉄心を得ようとした場合、安定した熱伝導性能を得、かつ接着性を確保することは困難であると考えられる。また、特開平２００１−２５０７２７号に記載されているような真空含浸法を採用した場合も適正な接着樹脂を選択しなければ樹脂が含浸されない事態が生じる。
【０００４】
以上、本発明は電磁鋼板間の接着強度および電気絶縁性を確保しつつ、積層方向の熱伝導性能を改善した積層鉄心を提供することを目的とする。
【０００５】
【課題を解決するための手段】
上記目的を解決するための手段を以下に示す。
【０００６】
（１）表面に絶縁性皮膜が存在する電磁鋼板を積層してなる鉄心において、電磁鋼板間に少なくとも接着性有機物からなる有機物層が存在し、該有機物層の平均厚さが４μｍ以下であることを特徴とする積層鉄心。
【０００７】
（２）表面に絶縁性皮膜が存在する電磁鋼板を積層してなる鉄心において、電磁鋼板間に少なくとも接着性有機物からなる有機物層が存在し、該有機物は硬化反応前の流動性が必要とされる温度での粘度が１．０Ｐａ・ｓ　以下であることを特徴とする積層鉄心
（３）表面に絶縁性皮膜が存在する電磁鋼板を積層してなる鉄心において、電磁鋼板間に少なくとも接着性有機物からなる有機物層が存在し、かつ積層鉄心の積層面に平行な方向のせん断強度が３００ｋｇ／ｃｍ^２　以上であることを特徴とする積層鉄心。
【０００８】
（４）表面に絶縁性皮膜が存在する電磁鋼板を積層してなる鉄心において、電磁鋼板間に少なくとも接着性有機物からなる有機物層が存在し、かつ積層鉄心の積層方向に平行な方向の熱伝導率が２Ｗ／ｍ・Ｋ以上であることを特徴とする積層鉄心。
【０００９】
（５）表面に絶縁性皮膜が存在する電磁鋼板を積層してなる鉄心において、電磁鋼板間に少なくとも接着性有機物からなる有機物層が存在し、かつ電磁鋼板の板厚が０．３５ｍｍ　以下であることを特徴とする積層鉄心。
【００１０】
（６）前記（１）から（５）に記載の積層鉄心で、電磁鋼板間に無機物粒子および有機物の混合物からなる接着層が存在することを特徴とする積層鉄心。
【００１１】
（７）前記（１）から（６）に記載の積層鉄心で、真空含浸法により積層電磁鋼板間に樹脂が注入されることを特徴とする積層鉄心。
【００１２】
（８）表面に絶縁性皮膜が存在する電磁鋼板を積層してなる鉄心において、電磁鋼板間に少なくとも接着性有機物からなる有機物層が存在し、該有機物層の平均厚さが４μｍ以下、該有機物の硬化反応前の流動性が必要とされる温度での粘度が１．０Ｐａ・ｓ　以下、かつ積層鉄心の積層面に平行な方向のせん断強度が
３００ｋｇ／ｃｍ^２　以上、積層鉄心の積層方向に平行な方向の熱伝導率が２Ｗ／ｍ・Ｋ以上で、電磁鋼板の板厚が０．３５ｍｍ　以下であることを特徴とする積層鉄心。
【００１３】
（９）少なくとも固定子鉄心が電磁鋼板を積層してなる鉄心である回転電機において、該固定子鉄心が前記（１）から（８）のいずれかからなることを特徴とする回転電機。
【００１４】
（１０）前記（９）に記載の積層鉄心を有し、電磁鋼板が回転電機を構成するケース内に積層された状態で接着性樹脂が含浸されることを特徴とする回転電機。
【００１５】
（１１）前記（９）に記載の積層鉄心を有し、電磁鋼板が回転電機を構成するケース内に積層されかつ巻線が施された状態で接着性樹脂が含浸されることを特徴とする回転電機。
【００１６】
（１２）電磁鋼板を積層してなる鉄心を有するトランスにおいて、該固定子鉄心が前記（１）から（８）に記載の積層鉄心のいずれかからなることを特徴とするトランス。
【００１７】
（１３）電磁鋼板を冶具により積み重ねる工程と、該積み重ねられた電磁鋼板を真空容器に入れ真空脱気する工程と、該真空脱気中に前記真空容器に硬化反応前の流動性が必要とされる温度での粘度が１．０Ｐａ・ｓ　以下である樹脂を注入し、該樹脂を浸入，硬化させる工程と、を有する積層鉄心の製造方法。
【００１８】
接着層の有機物は、コアに必要とされる接着強度や耐熱性を満たすものであれば、エポキシ系樹脂，アクリル系樹脂，フェノール系樹脂などのいずれでもよい。特に、積層鉄心が高温に曝される場合には熱硬化性の樹脂を用いることが好ましい。有機物の粘度が小さいほど有機物の電磁鋼板への浸入状態が良好である。樹脂粘度が高い場合には、積層電磁鋼板間への樹脂の含浸が不十分となり接着面積の割合が小さくなる。そのため、接着強度や熱伝導率の低下をまねく。一方、あらかじめ表面に接着性樹脂を塗布した電磁鋼板を用いた場合、接着面積が大きくなると大きな荷重をかけても接着不良が発生し、接着強度がばらついたり接着強度の低下をまねく。また、樹脂厚さを薄くすることも接着強度低下の原因となる。したがって、高い接着強度と熱伝導率を確保し、かつ高い電磁鋼板占積率を達成するためには、含浸法が最適であり、硬化反応前で流動性が必要とされる温度での粘度が１．０Ｐａ・ｓ　以下であることが好ましい。さらに、有機物の粘度が０．５Ｐａ・ｓ　以下に達する樹脂が好ましい。
【００１９】
電磁鋼板間の有機物単独層あるいは有機物と無機物粒子の混合層の厚さは、電磁鋼板の占積率やコアの熱伝導率の点からできるだけ薄い方がよい。特に、熱伝導率および接着強度の観点から接着樹脂の厚さは４μｍ以下が好ましい。
【００２０】
無機物粒子はＳｉＯ_２　，Ａｌ_２Ｏ_３，ＭｇＯ，ＴｉＯ_２　，ＢｅＯ，ＣａＯ，ＭｇＡｌ_２Ｏ_４の酸化物、Ｂ_４Ｃ　，ＳｉＣ，ＴｉＣの炭化物、ＢＮの窒化物であり、単独あるいは混合して用いる。樹脂および無機物粒子の混合層の厚さを薄くするためには、無機物粒子の最大粒径を小さく抑える必要がある。ただし、真空含浸法を用いた場合、電磁鋼板間に入り得る粒径の無機物粒子のみが鋼板間に入り込む。また、樹脂に対する無機物粒子の体積率が高いほど熱伝導率が大きくなるが、樹脂の粘性が高くなるので、無機物粒子の体積率を選択する必要がある。無機物粒子の体積率は、１０から７０％が好ましく、さらに２０から５０％が好ましい。
【００２１】
電磁鋼板は、無方向性電磁鋼板や方向性電磁鋼板に限らず、電磁鋼板として使用できる薄板全般に適用することができる。本発明を用いるにあたり板厚は特に限定されないが、接着方法の効果を勘案すると、０．３５ｍｍ　以下での適用が好ましく、０．２ｍｍ　以下がさらに好ましい。また、鉄心の鉄損を小さく押えるためには、絶縁皮膜が施された電磁鋼板を用いる必要がある。
【００２２】
本発明は、回転機，小型発電機，タービン発電機などの回転電機、およびトランスに用いることができる。積層鉄心を用いる機器であれば、その大小を問わず、また電磁鋼板の重ね方や分割方式にかかわらず、適用することができる。特に、回転電機では、ケース内に電磁鋼板を積層し、そのまま真空含浸により有機物を注入することができる。
【００２３】
【発明の実施の形態】
以下に本発明に係る実施の形態を示す。
【００２４】
（実施例１）
本実施例に係る積層鉄心を図６を用いて説明する。
【００２５】
電磁鋼板として片面約１μｍの絶縁皮膜が施されている板厚０．１５ｍｍ　の無方向性の電磁鋼板１を用いた。これを内径５０ｍｍ，外径１６０ｍｍの同心円環状に打抜き、打抜き時に発生するかえりを研削ローラーを通してできる限り除去した。この場合において表面の絶縁皮膜が除去されないように注意を払った。接着作業時における硬化前の温度、本実施例では５０℃における粘度が０．２Ｐａ・ｓ　である熱硬化性樹脂を用いた。
【００２６】
環状試料２００枚を治具に積み重ね、積厚を治具ボルトの締め付け具合により調整した。積層した環状鉄心２は、治具のまま、１３５℃，大気中で１２時間予備乾燥した。予備乾燥後、真空容器に入れ真空脱気し、１Ｔｏｒｒに到達してから１時間脱気を続けた。なおこのとき治具および鉄心はヒータにより５０℃に加熱した。その後、５０℃に保持された樹脂を真空容器内の治具および鉄心が入った容器に注入し、１時間保持した。このとき真空脱気は継続した。次に、大気を真空容器内に導入し、４気圧まで加圧し、１．５　時間保持した。その後、真空容器内を大気圧にし、治具および鉄心を取り出し、２１０℃に保持した電気炉に入れ、治具温度が２１０℃に達してから４時間保持した。上記のプロセスで真空含浸および熱硬化を施し、環状鉄心２を作製した。上記で作製した環状鉄心２から外径５０ｍｍの円柱をワイヤカットにより切り出し、さらに積層した鋼板をはく離して積厚が１２ｍｍとなるよう調整した。
【００２７】
このサンプルで積層方向の熱伝導率を定常法により測定した。樹脂厚さ割合０のときの熱伝導率は、電磁鋼板自身の面方向の熱伝導率とした。また、同一の鉄心から１０×２０ｍｍの角柱のサンプルを切り出し、これを樹脂埋め、研磨し、光学顕微鏡で平均的な鋼板間隔を測定し、これから絶縁皮膜厚さを差し引き樹脂厚さを求めた。
【００２８】
定常法により求められた熱伝導率の樹脂厚さ割合０の時に対する相対値と樹脂厚さ割合の関係を図１に示す。この図から明らかなように、積層方向の熱伝導率は面方向に比べ小さく、樹脂厚さが厚くなるに従い低下することがわかる。樹脂厚さが厚くなると急峻に熱伝導率が低下し、鋼板の面内熱伝導率の１／１０以下となる。熱伝導率の急峻な変化を示す樹脂厚さの小さい領域の外挿線と小さな熱伝導率を示す樹脂厚さの大きい領域における外挿線の交点は、接着樹脂厚さが４μｍの点であり、これより樹脂厚さが小さい領域とすることで高い熱伝導率を達成することができる。このことから、接着樹脂厚さは４μｍ以下が好ましい。この時、電磁鋼板１の絶縁皮膜の厚さを片面１μｍとすれば、電磁鋼板間隔は６μｍ以下とすることができる。
【００２９】
以上、本実施例により電磁鋼板間の接着強度および電気絶縁性を確保しつつ、積層方向の熱伝導性能を改善した積層鉄心をえることができる。
【００３０】
（実施例２）
実施例１と同様にして、片面約１μｍの絶縁皮膜が施されている板厚０．１５ｍｍの無方向性電磁鋼板を内径５０ｍｍ，外径１６０ｍｍの同心円環状に打ち抜き、真空含浸法により積層鉄心を作製した。このとき接着樹脂厚さは積厚を調整することで所定の厚さとした。また、真空含浸時の樹脂粘度は、樹脂温度により調整した。樹脂粘度の条件は、０．５　，１，３Ｐａ・ｓである。
【００３１】
上記で作製した環状鉄心から１０×２１ｍｍの角柱のサンプルを切り出し、これを積層厚さが３ｍｍとなるように調整し、せん断強度試験片とした。せん断強度試験は、樹脂埋め、研磨し、光学顕微鏡で平均的な鋼板間隔を測定し、これから絶縁皮膜厚さを差し引き樹脂厚さを求めた。作製した鉄心の樹脂厚さは、ほぼ０．５，１，４μｍであった。せん断強度は、ＪＩＳ　Ｋ７０７８に従って試験し求めた。支点間距離は１５ｍｍ、クロスヘッドの移動速度は１ｍｍ／ｍｉｎ　とした。この試験で得られたせん断強度の樹脂粘度０．５Ｐａ・ｓ　，樹脂厚さ４μｍのせん断強度に対する比をせん断強度比として、樹脂粘度および樹脂厚さに対する変化を図２に示す。樹脂粘度が小さければ、樹脂の流動性がよく、真空含浸において電磁鋼板間に十分に浸入していると考えられ、高いせん断強度を維持している。一方、樹脂厚さが小さい場合や樹脂粘度が高い場合には、せん断強度が小さくなる。本実施例によれば、樹脂粘度が１Ｐａ・ｓ以下であれば電磁鋼板間隔が小さくても高いせん断強度を維持できる。すなわち、樹脂粘度は１Ｐａ・ｓ以下が好ましい。
【００３２】
（実施例３）
片面約１μｍの絶縁皮膜が施されている板厚０．１５ｍｍ　の無方向性電磁鋼板から内径５０ｍｍ，外径１００，１５０，２００，２５０，３００ｍｍの同心円環状鉄心と打抜いた。打ち抜き時に発生するかえりは研削ローラーを通しできる限り除去した。ただし、表面の絶縁皮膜が除去されないように注意を払った。それぞれの同心円環状鉄心を実施例１の真空含浸法と同様にして鉄心を作製した。この時の接着樹脂は実施例１と同一のものを使用し、接着樹脂厚さは１μｍとした。一方、片面に約８μｍの接着性樹脂が塗装されている板厚０．１５ｍｍ　の無方向性電磁鋼板を用いても上記と同一の形状で同心円環状鉄心を作製した。鉄心接着の際には、２００℃，１０ｋｇ／ｃｍ^２　で加圧した。これらの鉄心の縦断面中心付近から１０×２１×３ｍｍのせん断試験サンプルをワイヤカットで切り出した。３ｍｍの厚さ方向に電磁鋼板１が積層されている。各鉄心においてそれぞれ１０個のサンプルでせん断試験を実施して、その平均値をせん断強度とした。真空含浸サンプルおよび接着樹脂塗装サンプルそれぞれの外径１００ｍｍの鉄心のせん断強度を１．０として、それぞれのせん断強度の相対値を図３に示す。真空含浸鉄心は外径が大きくなってもせん断強度に大きな違いはないが、接着皮膜塗装鋼板を用いた鉄心では外径が大きくなるに従いせん断強度が低下する。真空含浸の場合、樹脂を含浸させる距離が長くても樹脂粘度が低く、ある程度の鋼板間隙を有していれば、樹脂が鋼板間に十分に浸透し接着性を確保できる。一方、接着皮膜塗装鋼板の場合には、治具によるプレスで樹脂同士を接触・接着させるが、このとき内外径差が大きいと荷重のかかり方の不均一性や表面の凹凸などにより樹脂同士が十分に接触することができず、接着不良を生じる部分が多くなると推察される。また、この図には示されていないが、せん断強度のばらつきも真空含浸の場合は３％以内と小さく、接着皮膜塗装の場合は１０％以上であった。
【００３３】
また、接着樹脂厚さを変えて試作した鉄心のせん断強度を図４に示す。ここで、真空含浸による鉄心は、片面１μｍの絶縁皮膜が施された０．１５ｍｍ　の無方向性電磁鋼板を用い、治具の締め付け圧を変えることにより樹脂厚さを調節した。樹脂は上記と同様のものを使用した。一方、接着皮膜塗装の場合は、予め塗装する樹脂の膜厚を調整することで樹脂厚さを調整した。円環鉄心の内径は５０ｍｍ、外径は１００ｍｍとした。真空含浸による鉄心は、樹脂厚さが大きくなると若干せん断強度が低下するが、いずれも４００ｋｇ／ｃｍ^２　以上の値を示した。一方、接着皮膜塗装鋼板鉄心の場合は、樹脂厚さが６μｍ以上の場合は２００ｋｇ／ｃｍ^２　程度のせん断強度を示したが、４μｍではせん断強度が著しく低下した。これ以下の樹脂厚さの鉄心も作製可能であるが、ワイヤカットの段階で鋼板間にはく離を生じ、せん断試験サンプルを作製することができなかった。したがって、せん断強度の値を図４には示していない。
【００３４】
以上の結果より、真空含浸では鋼板間のせん断強度が高く占積率も高い鉄心を得ることができ、かつ鉄心幅が広くなってもその特性が大きく変化することはなかった。しかし、接着皮膜塗装鋼板を用いた場合は、鉄心幅が広かったりや樹脂厚さが薄かったりすると接着不良を発生しせん断強度が低下した。したがって、真空含浸は占積率および強度の高い鉄心を得るには最適な手法であり、かつ鉄心の大型化にも対応することができる。
【００３５】
（実施例４）
本発明の有効性を電磁鋼板の板厚を変えて検証した。電磁鋼板の厚さは、０．１，０．１５，０．２，０．３５，０．５ｍｍの５種とし、いずれも片面１μｍの絶縁皮膜を施している。これらを内径５０ｍｍ，外径１００ｍｍの同心円環状に打抜き、研削ローラを通してバリを削除した。これらを用いて実施例１と同一の真空含浸法により鉄心を作製した。このときの樹脂厚さは約２μｍとなるように治具を用いて積厚を調整した。一方、上記と同一の積厚に設定して、３．６ｋＪ／ｃｍ　の入熱でＴＩＧ溶接を外周面に６本施した。いずれも積厚は５０ｍｍである。ここで、内周側の鉄心厚さと外周側の鉄心厚さの違いを図５に示す。この図より、真空含浸の場合は内径側，外径側に厚さの変化はなかった。一方、溶接の場合は、板厚が薄くなると内径側が大きく広がり、鉄心形状を維持するには押え治具が必要と考えられる。したがって、板厚が０．３５ｍｍ　以下では溶接ではなく真空含浸の方が好ましく、特に板厚が０．２ｍｍ以下であればさらに好ましい。
【００３６】
（実施例５）
片面約１μｍの絶縁皮膜が施された０．１５ｍｍ　厚さの無方向性電磁鋼板を外径３００ｍｍ，内径１００ｍｍ，コアバック内径２３０ｍｍ，２４スロットの固定子形状に打ち抜いた。固定子の内径およびスロットを基準として、治具を用いて上下の電磁鋼板の位置を合わせ２４０ｍｍ積層した。これを樹脂厚さがほぼ１μｍとなるように治具で固定した。治具での固定は鉄心外側および内側に設置されたボルトで行った。また、治具およびボルト，ナットの表面は離型剤を塗り、かつ治具接合部にはシリコンゴムを塗り接合部への樹脂の浸入を避けた。次に、治具のまま積層電磁鋼板を１４０℃に加熱した恒温槽に入れ、大気中で約１５時間予備乾燥した。その後、真空チャンバーの中に入れ、１Ｔｏｒｒ以下で３時間真空脱気した。その後、エポキシ樹脂，無水酸硬化剤，硬化促進剤を混合した樹脂を５０℃に昇温し、粘度０．５Ｐａ・ｓ　で樹脂を注入した。ここでの樹脂は、エポキシ樹脂に油化シェルエポキシ製Ｌ−２８３２，ダウケミカル製ＤＥＲ−３３２の混合エポキシ樹脂を、無水酸硬化剤に日立化成工業製ＭＨＡＣ−Ｐを、硬化促進剤に和光純薬工業製Ｍｎ（ＩＩＩ）ＡＡを使用した。注入後、２時間真空に保持した後、接着樹脂を４気圧でさらに４時間加圧含浸させた。取り出された積層鋼板は、治具ごと恒温槽に入れ、熱硬化させた。硬化温度は２１０℃で、４時間保持した。その後、治具をはずし、余分な樹脂を削除した。このようにして作製した固定子鉄心に巻線を施し、固定子を完成させた。固定子鉄心の占積率は９８．２％　、せん断強度は７１２ｋｇ／ｃｍ^２　であった。ここで、固定子鉄心の温度測定のため、スロット内に熱電対を設置した。上記固定子と２極表面磁石回転子を、ハウジングおよびエンドブラケット内に設置し、表面磁石回転機とした。
【００３７】
一方、０．１５ｍｍ　厚さの電磁鋼板を上記固定子と同一の形状に打ち抜き、治具を用いて２４０ｍｍ積層し、占積率がほぼ９８％となるよう固定して、固定子側面をＹＡＧレーザーで溶接した。積厚２４０ｍｍを１パスでの溶接は不具合の発生が懸念されたことから、１パス５０ｍｍのビードを段違いに５本連ねて積厚２４０ｍｍを溶接した。５本一組のビードを外周面に６組置いた。溶接入熱条件は、３．２ｋＪ／ｃｍであり、ディフォーカス量が−１ｍｍのアンダーフォーカスである。これも上記と同様に巻線を施し、熱電対を設置して、表面磁石回転機を構成した。
【００３８】
上記２つの回転機を６００００ｒｐｍ　、無負荷で回転させ、そのときの固定子の温度および鉄損を測定した。ここでの鉄損は、全損失から機械損および銅損を引いた値である。表１に回転時の固定子温度および樹脂接着固定子を１．０としたときの溶接固定子の鉄損の比を示す。
【００３９】
【表１】

【００４０】
この結果から明らかなように、樹脂接着積層固定子は溶接積層固定子に比べ、最高到達温度が１３℃程度低下し、鉄損が約４割低下した。これは、樹脂接着積層による鉄損低減効果および熱伝導率向上の効果が出ているものと考えられる。
【００４１】
（実施例６）
片面約２μｍの絶縁皮膜が施されている０．２ｍｍ　の無方向性電磁鋼板を外径
１７０ｍｍ，内径８０ｍｍ，スロット外径１２０ｍｍ，スロット数１２で、かつキー溝を施した固定子形状に打ち抜いた。これをキーを設置したハウジング内に６０ｍｍ積層し、治具で固定した。その後、１３０℃の恒温槽で８時間予備乾燥し、真空チャンバーに入れた。真空が１Ｔｏｒｒ以下に達してから１時間保持し、樹脂を注入した。注入後さらに１時間保持した後、大気圧に戻しチャンバーから取り出した。これを２３０度の恒温槽に入れ、３時間保持した。その後、取り出して治具を取り外し、巻き線を施し固定子とした。巻き線は集中巻きである。回転子に８極の表面磁石回転子を採用し、回転機を構成した。電磁鋼板の占積率は９７．９％　であった。また、樹脂厚さは１．５μｍ　であった。この回転機を３６００ｒｐｍ　で合計で４０００時間回転させたが不具合は発生しなかった。
【００４２】
（実施例７）
片面約１μｍの絶縁皮膜が施されている０．１ｍｍ　の電磁鋼板を外径１３５ｍｍ，内径５０ｍｍ，スロット外形９０ｍｍ，スロット数１２の固定子形状に打ち抜いた。これを治具を用いて、８０ｍｍ積層し固定した。この治具ごと真空チャンバーに入れ、１Ｔｏｒｒ以下の真空で２時間真空脱気した。その後、粘度０．３Ｐａ・ｓ　の樹脂を注入し、さらに１時間真空に保持した。その後、３気圧に加圧し１時間保持し、大気圧に戻しチャンバーから取り出した。取り出し後、２１０℃の恒温槽に入れ、４時間熱硬化させた。これにより得られた固定子鉄心は、樹脂厚さ１μｍ，せん断強度４２０ｋｇ／ｃｍ^２　，占積率９７．２％　であった。また、熱伝導率は
２．３Ｗ／ｍ・Ｋ　であった。
【００４３】
（実施例８）
片面約２μｍの絶縁皮膜を施した０．３５ｍｍ　の電磁鋼板を外径３８０ｍｍ，内径２００ｍｍ，スロット外径２９０ｍｍ，スロット数４８の固定子をティースとコアバックを分割し、かつコアバックを周方向に１６分割した形状に打ち抜いた。ティース，コアバックそれぞれのセグメントを専用の治具で固定し、これを真空含浸により樹脂を注入した。樹脂はエポキシ樹脂であるが、最大粒径３μｍのＡｌ_２Ｏ_３粒子を体積率で０．２５　となるように配合した。完成した各セグメントは、平均占積率が９８．０％　、樹脂厚さが３μｍであり、熱伝導率が３．１Ｗ／ｍ・Ｋ　であった。また、断面観察の結果、鋼板間の樹脂にはＡｌ_２Ｏ_３粒子が分散していた。このことから、鋼板間隙が小さくてもそれ以下の粒径の無機物粒子は樹脂とともに浸入可能であることが明らかとなった。また、そのようにして浸入した無機物粒子は積層鉄心の熱伝導率の向上に効果が認められた。
【００４４】
以上の積層鉄心を採用することにより、電磁鋼板間の絶縁性を確保して渦電流損失の増加を防ぎ、かつ積層方向の熱伝導率を向上させることができるので積層鉄心の運転下での温度上昇を低く抑えることができる。また、その作製方法も簡便であり、特性の安定した積層鉄心を提供することができる。
【００４５】
本発明の固定子を採用することにより、良好なかつ安定な特性を有す回転機，小型発電機、あるいはタービン発電機等を提供することができる。
【００４６】
【発明の効果】
以上により電磁鋼板間の接着強度および電気絶縁性を確保しつつ、積層方向の熱伝導性能を改善した積層鉄心を提供することができる。
【図面の簡単な説明】
【図１】熱伝導率相対値と樹脂厚さの関係図。
【図２】積層鉄心のせん断強度比と樹脂粘度の関係図。
【図３】積層鉄心のせん断強度比と鉄心外径の関係図。
【図４】積層鉄心のせん断強度と樹脂厚さの関係図。
【図５】真空含浸とＴＩＧ溶接による鉄心の内外径の積厚差と電磁鋼板板厚の関係図。
【図６】実施例１に係る積層鉄心を示す図。
【符号の説明】
１…電磁鋼板、２…積層した環状鉄心。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an iron core formed by laminating electromagnetic steel sheets, and a rotating electric machine and a transformer using the same.
[0002]
[Prior art]
Rotating electric machines and transformers have a core constituted by a laminated core in which electromagnetic steel sheets are laminated. Until now, lamination was performed by methods such as caulking, welding, and clamping, but these lamination methods cannot be adopted depending on the application or structure. First, it is difficult to caulk when the thickness of the electromagnetic steel sheet is thin, for example, 0.2 mm or less, or when the electromagnetic steel sheet is difficult to plastically deform, such as a 6.5% silicon steel sheet. In addition, when the frequency is high or when the voltage is high, methods such as caulking, welding, and bolting may cause an electrical short circuit between the magnetic steel sheets, thereby increasing iron loss or damaging the device itself due to induced current. . Therefore, an electromagnetic steel sheet is adhered with an adhesive resin as in the techniques described in Japanese Patent Nos. Lamination methods have been proposed.
[0003]
[Problems to be solved by the invention]
However, in a rotating electric machine or the like, not only the adhesive strength for laminating electromagnetic steel sheets, but also the thermal conductivity and electrical insulation of the laminated iron core are important factors. In particular, good cooling efficiency is important for miniaturization or high output. From this point of view, Japanese Patent Application Laid-Open No. H11-150895 proposes a laminated iron core having improved thermal conductivity in the laminating direction and a method of manufacturing the same. However, in this method, when trying to obtain an iron core having a thin resin layer, it is considered that it is difficult to obtain stable heat conduction performance and secure adhesiveness. Also, when a vacuum impregnation method as described in Japanese Patent Application Laid-Open No. 2001-250727 is adopted, the resin may not be impregnated unless an appropriate adhesive resin is selected.
[0004]
As described above, an object of the present invention is to provide a laminated iron core having improved heat conduction performance in a laminating direction while securing the adhesive strength and electrical insulation between electromagnetic steel sheets.
[0005]
[Means for Solving the Problems]
Means for solving the above-mentioned object will be described below.
[0006]
(1) In an iron core formed by laminating electromagnetic steel sheets having an insulating film on the surface, at least an organic layer made of an adhesive organic substance exists between the electromagnetic steel sheets, and the average thickness of the organic layer is 4 μm or less. A laminated iron core characterized by the following.
[0007]
(2) In an iron core formed by laminating electromagnetic steel sheets having an insulating film on the surface, at least an organic layer made of an adhesive organic substance exists between the electromagnetic steel sheets, and the organic substance needs to have fluidity before a curing reaction. (3) a laminated iron core having an insulating film on the surface thereof, wherein the viscosity of the laminated iron core is not more than 1.0 Pa · s at a certain temperature. And a shear strength in a direction parallel to a lamination surface of the laminated core is 300 kg / cm ² or more.
[0008]
(4) In an iron core formed by laminating electromagnetic steel sheets having an insulating coating on the surface, at least an organic layer made of an adhesive organic substance exists between the electromagnetic steel sheets, and heat conduction in a direction parallel to the laminating direction of the laminated iron core. A laminated iron core having a ratio of 2 W / m · K or more.
[0009]
(5) In an iron core formed by laminating electromagnetic steel sheets having an insulating film on the surface, at least an organic layer made of an adhesive organic substance exists between the electromagnetic steel sheets, and the thickness of the electromagnetic steel sheet is 0.35 mm or less. A laminated iron core characterized in that:
[0010]
(6) The laminated core according to any one of (1) to (5), wherein an adhesive layer made of a mixture of inorganic particles and an organic substance is present between the magnetic steel sheets.
[0011]
(7) The laminated iron core according to (1) to (6), wherein a resin is injected between the laminated electromagnetic steel sheets by a vacuum impregnation method.
[0012]
(8) In an iron core formed by laminating electromagnetic steel sheets having an insulating film on the surface, at least an organic layer made of an adhesive organic substance is present between the electromagnetic steel sheets, and the organic substance layer has an average thickness of 4 μm or less. Has a viscosity of 1.0 Pa · s or less at a temperature at which fluidity is required before the curing reaction, and has a shear strength of 300 kg / cm ² or more in a direction parallel to the lamination surface of the lamination core. A laminated iron core having a thermal conductivity in a parallel direction of 2 W / m · K or more and a thickness of an electromagnetic steel sheet of 0.35 mm or less.
[0013]
(9) A rotating electric machine in which at least the stator core is an iron core formed by laminating electromagnetic steel sheets, wherein the stator core comprises any of the above (1) to (8).
[0014]
(10) A rotating electric machine having the laminated core according to (9), wherein the electromagnetic steel sheet is impregnated with an adhesive resin in a state of being laminated in a case constituting the rotating electric machine.
[0015]
(11) The laminated iron core according to (9), wherein the electromagnetic steel sheet is laminated in a case constituting a rotating electric machine and impregnated with an adhesive resin in a state where the winding is applied. Rotating electric machine.
[0016]
(12) A transformer having an iron core formed by laminating electromagnetic steel sheets, wherein the stator iron core is made of any one of the laminated iron cores described in (1) to (8).
[0017]
(13) A step of stacking electromagnetic steel sheets with a jig, a step of placing the stacked electromagnetic steel sheets in a vacuum vessel and vacuum degassing, and the vacuum vessel needs fluidity before a curing reaction during the vacuum degassing. A resin having a viscosity of 1.0 Pa · s or less at a certain temperature, and a step of infiltrating and curing the resin.
[0018]
The organic material of the adhesive layer may be any one of an epoxy resin, an acrylic resin, a phenol resin and the like as long as it satisfies the adhesive strength and heat resistance required for the core. In particular, when the laminated core is exposed to a high temperature, it is preferable to use a thermosetting resin. The smaller the viscosity of the organic substance, the better the state of penetration of the organic substance into the magnetic steel sheet. When the resin viscosity is high, the impregnation of the resin between the laminated electromagnetic steel sheets is insufficient, and the ratio of the bonding area is reduced. Therefore, the adhesive strength and the thermal conductivity are reduced. On the other hand, when an electromagnetic steel sheet having an adhesive resin applied to its surface in advance is used, when the bonding area is large, poor bonding occurs even when a large load is applied, resulting in variation in bonding strength or reduction in bonding strength. In addition, reducing the resin thickness also causes a decrease in adhesive strength. Therefore, in order to ensure high adhesive strength and thermal conductivity, and to achieve a high electrical steel sheet space factor, the impregnation method is optimal, and the viscosity at the temperature at which fluidity is required before the curing reaction is reduced. It is preferably 1.0 Pa · s or less. Further, a resin in which the viscosity of the organic substance reaches 0.5 Pa · s or less is preferable.
[0019]
The thickness of the organic substance alone layer or the mixed layer of organic substance and inorganic particles between the magnetic steel sheets is preferably as thin as possible from the viewpoint of the space factor of the magnetic steel sheet and the thermal conductivity of the core. In particular, the thickness of the adhesive resin is preferably 4 μm or less from the viewpoint of thermal conductivity and adhesive strength.
[0020]
Inorganic particles _{_{_{_{SiO 2, Al 2 O 3,}}}} MgO, TiO 2, BeO, CaO, oxides of _{_{_{MgAl 2 O 4, B 4 C}}} , SiC, TiC carbides, a nitride of BN, alone or in combination Used. In order to reduce the thickness of the mixed layer of resin and inorganic particles, it is necessary to keep the maximum particle size of the inorganic particles small. However, when the vacuum impregnation method is used, only inorganic particles having a particle size that can enter between the magnetic steel sheets enter into between the steel sheets. In addition, the higher the volume ratio of the inorganic particles with respect to the resin, the higher the thermal conductivity. However, since the viscosity of the resin increases, it is necessary to select the volume ratio of the inorganic particles. The volume ratio of the inorganic particles is preferably from 10 to 70%, more preferably from 20 to 50%.
[0021]
The electromagnetic steel sheet is not limited to a non-oriented electrical steel sheet and a grain-oriented electrical steel sheet, and can be applied to all thin sheets that can be used as an electromagnetic steel sheet. In using the present invention, the plate thickness is not particularly limited, but in consideration of the effect of the bonding method, the thickness is preferably 0.35 mm or less, more preferably 0.2 mm or less. Further, in order to reduce the iron loss of the iron core, it is necessary to use an electromagnetic steel sheet provided with an insulating film.
[0022]
INDUSTRIAL APPLICATION This invention can be used for rotary electric machines, such as a rotary machine, a small generator, a turbine generator, and a transformer. As long as the device uses a laminated iron core, it can be applied regardless of its size and regardless of the method of laminating or dividing the electromagnetic steel sheets. In particular, in a rotating electric machine, an electromagnetic steel sheet can be laminated in a case, and an organic substance can be directly injected by vacuum impregnation.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment according to the present invention will be described below.
[0024]
(Example 1)
A laminated core according to the present embodiment will be described with reference to FIG.
[0025]
A non-oriented electromagnetic steel sheet 1 having a thickness of 0.15 mm and having an insulating film of about 1 μm on one side was used as the electromagnetic steel sheet. This was punched into a concentric annular ring having an inner diameter of 50 mm and an outer diameter of 160 mm, and burrs generated during the punching were removed as much as possible through a grinding roller. In this case, care was taken so that the insulating film on the surface was not removed. A thermosetting resin having a viscosity of 0.2 Pa · s at a temperature before curing during the bonding operation, in this example, at 50 ° C. was used.
[0026]
200 annular samples were stacked on a jig, and the thickness of the stack was adjusted by the degree of tightening of jig bolts. The laminated core 2 was preliminarily dried at 135 ° C. in the atmosphere for 12 hours while keeping the jig. After the preliminary drying, it was placed in a vacuum vessel and degassed in vacuum. After reaching 1 Torr, degassing was continued for 1 hour. At this time, the jig and the iron core were heated to 50 ° C. by a heater. Thereafter, the resin held at 50 ° C. was poured into a container containing a jig and an iron core in a vacuum container, and held for 1 hour. At this time, vacuum degassing was continued. Next, air was introduced into the vacuum vessel, pressurized to 4 atm, and held for 1.5 hours. Thereafter, the inside of the vacuum vessel was set to the atmospheric pressure, the jig and the iron core were taken out, placed in an electric furnace maintained at 210 ° C., and held for 4 hours after the jig temperature reached 210 ° C. Vacuum impregnation and heat curing were performed in the above-described process to produce the annular core 2. A cylinder having an outer diameter of 50 mm was cut out from the annular core 2 prepared as described above by wire cutting, and the laminated steel sheets were peeled off to adjust the stacked thickness to 12 mm.
[0027]
With this sample, the thermal conductivity in the stacking direction was measured by a steady state method. The thermal conductivity when the resin thickness ratio was 0 was defined as the thermal conductivity in the plane direction of the electromagnetic steel sheet itself. In addition, a sample of 10 × 20 mm prism was cut out from the same iron core, filled with a resin, polished, and measured for an average steel plate interval with an optical microscope, and the thickness of the insulating film was subtracted from this to obtain the resin thickness.
[0028]
FIG. 1 shows the relationship between the relative value of the thermal conductivity obtained by the steady-state method and the resin thickness ratio when the resin thickness ratio is 0. As is apparent from this figure, the thermal conductivity in the laminating direction is smaller than that in the plane direction, and decreases as the resin thickness increases. As the resin thickness increases, the thermal conductivity sharply decreases, and becomes 1/10 or less of the in-plane thermal conductivity of the steel sheet. The intersection of the extrapolated line in the region of small resin thickness showing a steep change in thermal conductivity and the extrapolated line in the region of large resin thickness showing small thermal conductivity is the point where the adhesive resin thickness is 4 μm. A high thermal conductivity can be achieved by making the resin thickness smaller than this. For this reason, the thickness of the adhesive resin is preferably 4 μm or less. At this time, if the thickness of the insulating film of the magnetic steel sheet 1 is 1 μm on one side, the interval between the magnetic steel sheets can be 6 μm or less.
[0029]
As described above, according to the present embodiment, it is possible to obtain a laminated iron core having improved heat conduction performance in the laminating direction while securing the adhesive strength between the magnetic steel sheets and the electrical insulation.
[0030]
(Example 2)
In the same manner as in Example 1, a non-oriented electrical steel sheet having a thickness of 0.15 mm and having an insulating film of about 1 μm on one side is punched into a concentric annular ring having an inner diameter of 50 mm and an outer diameter of 160 mm. Produced. At this time, the thickness of the adhesive resin was adjusted to a predetermined thickness by adjusting the stack thickness. The resin viscosity during vacuum impregnation was adjusted by the resin temperature. The condition of the resin viscosity is 0.5, 1, 3 Pa · s.
[0031]
A sample of a 10 × 21 mm prism was cut out from the annular core prepared above, and adjusted so that the lamination thickness became 3 mm, to obtain a shear strength test piece. In the shear strength test, the resin was filled and polished, the average steel sheet distance was measured with an optical microscope, and the thickness of the insulating film was subtracted therefrom to obtain the resin thickness. The resin thickness of the manufactured iron core was approximately 0.5, 1, 4 μm. The shear strength was determined by testing according to JIS K7078. The distance between the fulcrums was 15 mm, and the moving speed of the crosshead was 1 mm / min. FIG. 2 shows changes in the resin viscosity and the resin thickness, where the ratio of the shear strength obtained in this test to the resin viscosity of 0.5 Pa · s and the resin thickness of 4 μm is defined as the shear strength ratio. If the resin viscosity is low, the fluidity of the resin is good, and it is considered that the resin has sufficiently penetrated between the electromagnetic steel sheets in vacuum impregnation, and high shear strength is maintained. On the other hand, when the resin thickness is small or the resin viscosity is high, the shear strength becomes small. According to this embodiment, if the resin viscosity is 1 Pa · s or less, high shear strength can be maintained even if the interval between the electromagnetic steel sheets is small. That is, the resin viscosity is preferably 1 Pa · s or less.
[0032]
(Example 3)
A concentric annular iron core having an inner diameter of 50 mm and an outer diameter of 100, 150, 200, 250, and 300 mm was punched from a non-oriented electrical steel sheet having a thickness of 0.15 mm and having an insulating film of about 1 μm on one side. Burrs generated during punching were removed as much as possible through a grinding roller. However, care was taken so that the insulating film on the surface was not removed. Each concentric annular core was manufactured in the same manner as in the vacuum impregnation method of Example 1. At this time, the same adhesive resin as in Example 1 was used, and the thickness of the adhesive resin was 1 μm. On the other hand, even when a non-oriented electrical steel sheet having a thickness of 0.15 mm and coated with an adhesive resin of about 8 μm on one surface was used, a concentric annular core having the same shape as above was produced. At the time of iron core bonding, pressure was applied at 200 ° C. and 10 kg / cm ² . A shear test sample of 10 × 21 × 3 mm was cut out from the vicinity of the center of the vertical section of these iron cores by wire cutting. The electromagnetic steel sheets 1 are stacked in a thickness direction of 3 mm. A shear test was performed on 10 samples for each iron core, and the average value was defined as the shear strength. Assuming that the shear strength of the iron core having an outer diameter of 100 mm of each of the vacuum impregnated sample and the adhesive resin coating sample is 1.0, the relative values of the respective shear strengths are shown in FIG. Although the vacuum impregnated iron core has no significant difference in the shear strength even when the outer diameter increases, the shear strength of the iron core using the steel sheet coated with the adhesive film decreases as the outer diameter increases. In the case of vacuum impregnation, even if the resin impregnating distance is long, if the resin viscosity is low and there is a certain gap between the steel plates, the resin can sufficiently penetrate between the steel plates and the adhesiveness can be secured. On the other hand, in the case of an adhesive-coated steel sheet, the resins are brought into contact with each other by pressing with a jig, but if the difference between the inner and outer diameters is large at this time, the resins may become uneven due to unevenness in how the load is applied and unevenness on the surface. It is presumed that sufficient contact could not be made, and the portion where poor adhesion occurred increased. Although not shown in this figure, the variation in the shear strength was as small as 3% or less in the case of vacuum impregnation and 10% or more in the case of coating with an adhesive film.
[0033]
FIG. 4 shows the shear strength of the iron cores experimentally manufactured by changing the thickness of the adhesive resin. Here, as the iron core formed by vacuum impregnation, a 0.15 mm non-oriented electrical steel sheet coated with an insulating film of 1 μm on one side was used, and the resin thickness was adjusted by changing the clamping pressure of the jig. The same resin as described above was used. On the other hand, in the case of adhesive film coating, the resin thickness was adjusted by adjusting the film thickness of the resin to be coated in advance. The inner diameter of the annular core was 50 mm, and the outer diameter was 100 mm. The shear strength of the iron core obtained by vacuum impregnation slightly decreases with an increase in the resin thickness, but in each case, the iron core shows a value of 400 kg / cm ² or more. On the other hand, in the case of a steel core coated with an adhesive film, when the resin thickness was 6 μm or more, the shear strength was about 200 kg / cm ^2, but when the resin thickness was 4 μm, the shear strength was significantly reduced. Although an iron core with a resin thickness of less than this can be produced, the steel sheet peeled off at the wire cutting stage, and a shear test sample could not be produced. Therefore, the value of the shear strength is not shown in FIG.
[0034]
From the above results, in the vacuum impregnation, it was possible to obtain an iron core having a high shear strength between steel sheets and a high space factor, and its characteristics did not change significantly even when the iron core width was widened. However, when the steel sheet coated with the adhesive film was used, if the iron core width was wide or the resin thickness was thin, poor adhesion occurred and the shear strength was reduced. Therefore, vacuum impregnation is an optimal method for obtaining an iron core having a high space factor and strength, and can cope with an increase in the size of the iron core.
[0035]
(Example 4)
The effectiveness of the present invention was verified by changing the thickness of the magnetic steel sheet. The thicknesses of the electromagnetic steel sheets are five types of 0.1, 0.15, 0.2, 0.35, and 0.5 mm, and each of them has an insulating film of 1 μm on one side. These were punched into concentric rings having an inner diameter of 50 mm and an outer diameter of 100 mm, and burrs were removed through a grinding roller. Using these, an iron core was produced by the same vacuum impregnation method as in Example 1. The stack thickness was adjusted using a jig so that the resin thickness at this time was about 2 μm. On the other hand, the same stack thickness was set as above, and six TIG weldings were performed on the outer peripheral surface with a heat input of 3.6 kJ / cm 2. In each case, the stack thickness is 50 mm. Here, the difference between the inner core thickness and the outer core thickness is shown in FIG. From this figure, in the case of vacuum impregnation, there was no change in the thickness on the inner diameter side and the outer diameter side. On the other hand, in the case of welding, when the plate thickness is reduced, the inner diameter side is greatly widened, and it is considered that a holding jig is required to maintain the iron core shape. Therefore, when the plate thickness is 0.35 mm or less, vacuum impregnation rather than welding is more preferable, and particularly preferably, the plate thickness is 0.2 mm or less.
[0036]
(Example 5)
A 0.15 mm-thick non-oriented electrical steel sheet provided with an insulating film of about 1 μm on one side was punched into a stator shape having an outer diameter of 300 mm, an inner diameter of 100 mm, a core back inner diameter of 230 mm, and 24 slots. Based on the inner diameter of the stator and the slots, the upper and lower electromagnetic steel sheets were aligned using a jig, and laminated by 240 mm. This was fixed with a jig so that the resin thickness was approximately 1 μm. Fixing with a jig was performed using bolts installed on the outside and inside of the iron core. The surface of the jig and the bolts and nuts were coated with a release agent, and the jig joint was coated with silicone rubber to prevent resin from entering the joint. Next, the laminated electromagnetic steel sheet was put into a thermostat heated to 140 ° C. while being kept in a jig, and was preliminarily dried in the air for about 15 hours. Then, it was put in a vacuum chamber and degassed under vacuum at 1 Torr or less for 3 hours. Thereafter, the temperature of the resin in which the epoxy resin, the acid anhydride curing agent, and the curing accelerator were mixed was raised to 50 ° C., and the resin was injected with a viscosity of 0.5 Pa · s. The resin used here was a mixed epoxy resin of L-2832 made by Yuka Shell Epoxy as an epoxy resin, DER-332 made by Dow Chemical, MHAC-P manufactured by Hitachi Chemical Co., Ltd. as an acid anhydride curing agent, and Wako Pure Chemical Co., Ltd. as a curing accelerator. Mn (III) AA manufactured by Yakuhin Kogyo was used. After the injection, the vacuum was maintained for 2 hours, and then the adhesive resin was pressure-impregnated at 4 atm for 4 hours. The removed laminated steel sheet was put into a thermostat together with the jig, and was thermally cured. The curing temperature was 210 ° C. and held for 4 hours. Thereafter, the jig was removed, and excess resin was removed. A winding was applied to the stator core thus produced to complete the stator. The space factor of the stator core was 98.2%, and the shear strength was 712 kg / cm ² . Here, a thermocouple was installed in the slot for measuring the temperature of the stator core. The stator and the two-pole surface magnet rotator were installed in a housing and an end bracket to obtain a surface magnet rotator.
[0037]
On the other hand, an electromagnetic steel sheet having a thickness of 0.15 mm was punched out in the same shape as the above-mentioned stator, and was laminated 240 mm using a jig, and was fixed so that the space factor was approximately 98%. Welded. Since welding of a stack thickness of 240 mm in one pass was feared to cause a defect, five beads of 50 mm in a single pass were connected in a stepwise manner to weld the stack thickness of 240 mm. Six sets of five beads were placed on the outer peripheral surface. The welding heat input condition was 3.2 kJ / cm, and the amount of defocus was underfocus of -1 mm. In this case as well, winding was performed and a thermocouple was installed in the same manner as described above, to configure a surface magnet rotating machine.
[0038]
The two rotating machines were rotated at 60,000 rpm with no load, and the temperature and iron loss of the stator at that time were measured. The iron loss here is a value obtained by subtracting the mechanical loss and the copper loss from the total loss. Table 1 shows the stator temperature during rotation and the ratio of iron loss of the welded stator when the resin-bonded stator is set to 1.0.
[0039]
[Table 1]

[0040]
As is clear from these results, the maximum temperature of the resin-bonded laminated stator was reduced by about 13 ° C. and the iron loss was reduced by about 40% as compared with the welded laminated stator. This is considered to be due to the effect of reducing the iron loss and improving the thermal conductivity due to the resin bonding lamination.
[0041]
(Example 6)
A 0.2 mm 2 non-oriented electrical steel sheet with an insulation coating of about 2 μm on one side was punched out into a stator shape with an outer diameter of 170 mm, an inner diameter of 80 mm, a slot outer diameter of 120 mm, 12 slots, and a keyway. . This was laminated 60 mm in a housing in which a key was installed, and fixed with a jig. Then, it was preliminarily dried in a thermostat at 130 ° C. for 8 hours and placed in a vacuum chamber. After the vacuum reached 1 Torr or less, the temperature was maintained for 1 hour, and the resin was injected. After an additional hour was maintained after the injection, the pressure was returned to atmospheric pressure and the chamber was taken out of the chamber. This was put into a 230 degreeC thermostat, and was held for 3 hours. Thereafter, the jig was taken out, the jig was removed, and winding was performed to obtain a stator. The winding is concentrated winding. A rotating machine was configured by employing an eight-pole surface magnet rotor. The space factor of the magnetic steel sheet was 97.9%. The resin thickness was 1.5 μm. This rotary machine was rotated at 3600 rpm for a total of 4000 hours, but no problem occurred.
[0042]
(Example 7)
A 0.1 mm 2 electromagnetic steel sheet provided with an insulating film of about 1 μm on one side was punched into a stator shape having an outer diameter of 135 mm, an inner diameter of 50 mm, a slot outer diameter of 90 mm, and 12 slots. This was laminated and fixed by 80 mm using a jig. The jig was put in a vacuum chamber and vacuum-evacuated at a vacuum of 1 Torr or less for 2 hours. Thereafter, a resin having a viscosity of 0.3 Pa · s was injected, and the vacuum was maintained for another hour. Thereafter, the pressure was increased to 3 atm, maintained for 1 hour, returned to atmospheric pressure, and taken out of the chamber. After being taken out, it was placed in a thermostat at 210 ° C. and thermally cured for 4 hours. The stator core thus obtained had a resin thickness of 1 μm, a shear strength of 420 kg / cm ² , and a space factor of 97.2%. The thermal conductivity was 2.3 W / m · K.
[0043]
(Example 8)
A 0.35 mm electromagnetic steel sheet coated with an insulating film of about 2 μm on one side is divided into teeth and a core back with a stator having an outer diameter of 380 mm, an inner diameter of 200 mm, a slot outer diameter of 290 mm, and 48 slots. It was punched out into 16 divided shapes. Each segment of the teeth and the core back was fixed with a special jig, and resin was injected by vacuum impregnation. The resin is an epoxy resin, and Al ₂ O ₃ particles having a maximum particle size of 3 μm were blended so as to have a volume ratio of 0.25. Each completed segment had an average space factor of 98.0%, a resin thickness of 3 μm, and a thermal conductivity of 3.1 W / m · K. Further, as a result of the cross-sectional observation, Al ₂ O ₃ particles were dispersed in the resin between the steel sheets. From this, it became clear that even if the gap between the steel sheets is small, the inorganic particles having a particle size smaller than the gap can penetrate together with the resin. In addition, the inorganic particles thus penetrated were found to be effective in improving the thermal conductivity of the laminated core.
[0044]
By adopting the above laminated core, it is possible to secure the insulation between the magnetic steel sheets, prevent the increase of the eddy current loss, and improve the thermal conductivity in the laminating direction. The rise can be kept low. Further, the manufacturing method is simple, and a laminated iron core having stable characteristics can be provided.
[0045]
By employing the stator of the present invention, it is possible to provide a rotating machine, a small generator, a turbine generator, or the like having good and stable characteristics.
[0046]
【The invention's effect】
As described above, it is possible to provide a laminated iron core having improved heat conduction performance in the laminating direction while securing the adhesive strength between the electromagnetic steel sheets and the electrical insulation.
[Brief description of the drawings]
FIG. 1 is a diagram showing a relationship between a relative value of thermal conductivity and a resin thickness.
FIG. 2 is a diagram showing a relationship between a shear strength ratio of a laminated iron core and a resin viscosity.
FIG. 3 is a diagram showing a relationship between a shear strength ratio of a laminated core and an outer diameter of the core.
FIG. 4 is a diagram showing the relationship between the shear strength of a laminated core and the resin thickness.
FIG. 5 is a diagram showing the relationship between the thickness difference between the inner and outer diameters of the iron core by vacuum impregnation and TIG welding and the thickness of the electromagnetic steel sheet.
FIG. 6 is a view showing a laminated core according to the first embodiment.
[Explanation of symbols]
1 ... Electromagnetic steel sheet, 2 ... Laminated annular core.

Claims

An iron core formed by laminating electromagnetic steel sheets having an insulating film on the surface,
A laminated iron core, wherein an organic material layer comprising at least an adhesive organic material exists between magnetic steel sheets, and the average thickness of the organic material layer is 4 μm or less.

2. The laminated core according to claim 1, wherein the adhesive organic substance has a viscosity at a temperature at which fluidity before a curing reaction is required is 1.0 Pa · s 反応 or less. 3.

Laminated core according to claim 1, wherein the shear strength in the direction parallel to the lamination surface of the laminated iron core, characterized in that it is 300 kg / cm ² or more.

The laminated core according to claim 1, wherein the thermal conductivity of the laminated core in a direction parallel to the laminating direction is 2 W / m · K or more.

2. The laminated core according to claim 1, wherein the thickness of the electromagnetic steel sheet is 0.35 mm or less.

The laminated core according to claim 1, wherein the organic layer includes inorganic particles.

The laminated iron core according to claim 1, wherein the organic material layer is injected between laminated electromagnetic steel sheets by a vacuum impregnation method.

An iron core formed by laminating magnetic steel sheets having an insulating film on the surface, wherein at least an organic layer made of an adhesive organic substance is present between the magnetic steel sheets, and the average thickness of the organic material layer is 4 μm or less. The viscosity of the organic material at a temperature where fluidity is required before the curing reaction is 1.0 Pa · s or less, and the shear strength in a direction parallel to the lamination surface of the laminated core is 300 kg / cm ² or more. A laminated iron core, wherein the thermal conductivity in a direction parallel to the laminating direction is 2 W / m · K or more, and the thickness of the electromagnetic steel sheet is 0.35 mm or less.

A rotating electric machine having, as a stator, an iron core formed by laminating electromagnetic steel sheets, wherein the stator iron core is the laminated iron core according to claim 1.

The rotating electric machine according to claim 9, wherein the electromagnetic steel sheet is impregnated with an adhesive resin in a state of being stacked in a case constituting the rotating electric machine.

The rotating electric machine according to claim 9, wherein the electromagnetic steel sheet is laminated in a case constituting the rotating electric machine and impregnated with an adhesive resin in a state where the winding is applied.

A transformer having an iron core formed by laminating electromagnetic steel sheets, wherein the stator iron core is the laminated iron core according to claim 1.

Stacking electromagnetic steel sheets with jigs,
A step of placing the stacked magnetic steel sheets in a vacuum vessel and vacuum degassing,
Injecting a resin having a viscosity of 1.0 Pa · s or less at a temperature at which fluidity before a curing reaction is required into the vacuum container during the vacuum degassing, infiltrating and curing the resin,
A method for producing a laminated iron core having: