JP3598647B2

JP3598647B2 - Hermetic electric compressor

Info

Publication number: JP3598647B2
Application number: JP10296796A
Authority: JP
Inventors: 義明原川; 彰夫松岡; 政美佐貫
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 1996-04-24
Filing date: 1996-04-24
Publication date: 2004-12-08
Anticipated expiration: 2016-04-24
Also published as: JPH09287585A

Description

【０００１】
【発明の属する技術分野】
本発明は、冷凍装置における冷媒圧縮機等に用いられる密閉型電動圧縮機に関し、特に、電気駆動源を内蔵した電動スクロール圧縮機等に関する。
【０００２】
【従来の技術】
図９に、従来の電動スクロール圧縮機の断面図を示す。図９において、１は電動スクロール圧縮機のケースをなすアルミ製のハウジングで、このハウジング１は、第１ハウジング１１、第２ハウジング１２、および、第３ハウジング１３からなる。そして、第３、第２ハウジング１３、１２内には、圧縮部２としての固定スクロール部２１および旋回スクロール部２２が設けられ、第１ハウジング１１内には、主軸３と、この主軸３を駆動する電動機部４としての、回転子４１および鉄製の固定子４２が備えられている。
【０００３】
そして、主軸３は、第２ハウジング１２に設けられた第１軸受け５と、第１ハウジング１１に設けられた第２軸受け６とにより、回動可能に保持されている。なお、第１ハウジング１１と第２ハウジング１２、および、第２ハウジング１２と第３ハウジング１３とは、それぞれ、図示しないボルトにより締結固定されている。また、主軸３を支持している第１軸受け５と第２軸受け６との中心を合わせるために、第１ハウジング１１と第２ハウジング１２との芯出しを行っている。
【０００４】
具体的には、第１ハウジング１１の第２ハウジング１２側（開口部１１ｃ側）端面１１ａ、および、第２ハウジング１２の第１ハウジング１１側端面１２ａの外周部には、これら端面の半径方向外方に向かってのびる突出部が４カ所、一体に形成されており、これらの突出部に、上記ボルトを通すボルト孔が４カ所、および、芯出し用の孔が２ヵ所設けられている。
【０００５】
この芯出し用の孔は、それぞれ、軸受け孔１２１、および、軸受け孔１１４の中心から所定距離の位置で、かつ、対角線上に設けられており、この芯出し用の孔にピンを挿嵌して、第１、第２ハウジング１１、１２を組付けることで、芯出しを行って軸受け孔１２１と軸受け孔１１４との中心を合わせている。これにより、主軸３がスムースに回動するようになっている。
【０００６】
【発明が解決しようとする課題】
ところで、圧縮機を構成する第１ハウジング１１に固定子４２を固定する方法としては、焼き嵌め固定が一般的となっている。焼き嵌め固定とは、第１ハウジング１１の内径を固定子４２の外径よりもわずかに（数百μｍ程度）小さく構成し、第１ハウジング１１を高温状態にすることで第１ハウジング１１を熱膨張させ、この熱膨張した第１ハウジング１１内に、常温の固定子４２を嵌合することで第１ハウジング１１が収縮して固定子４２を締めつけ固定するものである。
【０００７】
ところが、従来技術では、第１ハウジング１１がアルミ製で、固定子４２が鉄製であるため、熱膨張した第１ハウジング１１内に、常温の固定子４２を嵌合すると、第１ハウジング１１において固定子４２の嵌合される部分は、アルミよりも剛性に優れた鉄からなる固定子４２の形状までしか戻れないが、第１ハウジング１１において固定子４２の嵌合されない部分は、熱膨張前の第１ハウジング１１の形状に戻ろうとする。
【０００８】
すると、固定子４２の外周面全面から第１ハウジング１１に力が加えられることとなり、しかも、第１ハウジング１１は、一端に底面部１１ｂ、他端に開口部１１ｃを備える筒状部材からなるため、第１ハウジング１１は、この第１ハウジング１１の開口部１１ｃ側が押し広げられるような状態で大きく変形してしまう。具体的には、第１ハウジング１１の図９中左側部分の内径が約６０μｍ（０．０６ｍｍ）程度広がってしまう。これに対して、第２ハウジング１２は焼き嵌め固定の必要がないので、変形は生じない。よって、芯出し用の孔を予め形成してから、焼き嵌め固定を行うと、第２ハウジング１２の孔の位置と、第１ハウジング１１の孔の位置とが大きくずれてしまう。
【０００９】
このため、第１ハウジング１１内に固定子４２を焼き嵌め固定してから、上記芯出し用の孔を切削加工しなければならない。つまり、第１ハウジング１１の形成時に同時に上記芯出し用の孔を形成することができず、さらに、第１ハウジング１１内に固定子４２を固定してから、上記芯出し用の孔を加工するため、重量の点から取り扱いが困難であるため、電動スクロール圧縮機の形成工程が複雑となり、コスト高となる。
【００１０】
本発明は上記点に鑑みてなされたもので、焼き嵌め後の第１ハウジングの変形を小さく抑えて、第１ハウジング形成時に同時に芯出し用の孔を形成することを目的とする。
【００１１】
【課題を解決するための手段】
本発明は上記目的を達成するため、以下の技術的手段を採用する。
請求項１ないし５に記載の発明においては、軸部材（３）の一端が第１ハウジング（１１）の中心部（１１４）に、他端が第２ハウジング（１２）の中心部（１２１）に回動可能に支持されており、一端に底面部（１１ｂ）、他端に開口部（１１ｃ）を有する筒状の第１ハウジング（１１）に固定子（４２）が焼き嵌め固定される密閉型電動圧縮機において、第１ハウジング（１１）と固定子（４２）との嵌合部分の、軸方向の一部に隙間（Ｃ）を設けて、第１ハウジング（１１）と固定子（４２）との焼き嵌め圧入固定部（１１６、１１６ａ、１１６ｂ）の軸方向長さを短くすることを特徴としている。
【００１２】
この技術的手段によれば、焼き嵌め時において、固定子（４２）の外周面の一部が第１ハウジング（１１）の内周面に圧着するため、固定子（４２）から第１ハウジング（１１）の半径方向外方に向かって加わる力が、従来に比べて小さくなる。よって、第１ハウジング（１１）の開口部（１１ｃ）側端面（１１ａ）における、半径方向外方への広がりは小さくなり、かつ、第１ハウジング（１１）の端面（１１ａ）の反りも小さくなる。
【００１３】
従って、第１ハウジング（１１）の形成加工時において、第１ハウジング（１１）の端面（１１ａ）に芯出し用の孔（１１３）を同時に形成し、その後、焼き嵌めを行っても、第１ハウジング（１１）の孔（１１３）と、第２ハウジング（１２）の孔との位置のずれは小さいので、第１ハウジング（１１）と第２ハウジング（１２）との芯出しを、初期の設計どおりに確実に行うことができる。このため、従来のように、芯出し用の孔（１１３）を焼き嵌め後に形成する必要はなく、密閉型電動圧縮機の形成工程が単純となり、コスト安に密閉型電動圧縮機を形成することができる。
【００１４】
また、請求項２に記載の発明では、隙間（Ｃ）は、第１ハウジング（１１）の開口部（１１ｃ）側に設けられ、焼き嵌め圧入固定部（１１６）は、第１ハウジング（１１）の底面部（１１ｂ）側に設けられていることを特徴としている。
従って、焼き嵌め時において、固定子（４２）から第１ハウジング（１１）の半径方向外方に向かって加わる力がより小さくなるので、第１ハウジング（１１）の端面（１１ａ）における、半径方向外方への広がりはより小さくなり、かつ、第１ハウジング（１１）の端面（１１ａ）の反りもより小さくなる。よって、第１ハウジング（１１）の孔（１１３）と、第２ハウジング（１２）の孔との位置のずれをより小さくすることができ、上記芯出しをより確実に行うことができる。
【００１５】
また、請求項４に記載の発明では、隙間（Ｃ）は、固定子（４２）の、上記軸方向中央部に相当する部分に設けられ、焼き嵌め圧入固定部（１１６、１１６ａ、１１６ｂ）は、固定子（４２）の上記軸方向一端（４２ａ）側、および、上記軸方向他端（４２ｂ）側に設けられていることを特徴としている。
この技術的手段によれば、隙間（Ｃ）を設けることで、第１ハウジング（１１）の孔（１１３）と、第２ハウジング（１２）の孔との位置のずれを小さく保ちつつ、固定子（４２）の両端（４２ａ、４２ｂ）を圧入固定することで、第１ハウジング（１１）内に、より確実に固定することができる。
【００１６】
【発明の実施の形態】
以下、本発明を図に示す実施形態について説明する。
（第１の実施形態）
図１は、第１の実施形態の電動スクロール圧縮機の断面図を示すもので、図１において、１は電動スクロール圧縮機のケースをなすハウジングで、このハウジング１は、第１ハウジング１１、第２ハウジング１２、および第３ハウジング１３からなる。そして、第１ハウジング１１と第２ハウジング１２、および、第２ハウジング１２と第３ハウジング１３とは、ぞれぞれ、図示しないボルトにより締結固定されて、全体として１つの密閉ハウジング１を形成している。
【００１７】
なお、このハウジング１は、軽量化の目的で、アルミニウム合金からなり、第１ハウジング１１は、一端に底面部１１ｂ、他端に開口部１１ｃを有する筒状部材からなる。そして、第２、第３ハウジング１２、１３内には、圧縮部２としての固定スクロール部２１および旋回スクロール部２２が設けられ、第１ハウジング１１内には、主軸３と、この主軸３を駆動する電動機部４としての回転子４１および鉄製の固定子４２とが備えられている。
【００１８】
そして、第２ハウジング１２の中心部に設けられた第１軸受け５と、第１ハウジング１１の中心部に設けられた第２軸受け６とにより、主軸（軸部材）３を回転可能に保持している。第１軸受け５は、第２ハウジング１２に形成された軸受け孔１２１に圧入固定され、第２軸受け６は、第１ハウジング１１に形成された軸受け孔１１４に圧入固定されている。また、第１ハウジング１１の内周面において、固定子４２の一端４２ａの角に対応する位置には、リング状にわずかに切り欠いた溝１１５が形成されている。
【００１９】
なお、溝部１１５の内径を、第１ハウジング１１の底面部１１ｂ側部分の内径よりも大きく形成することにより、溝１１５の底面部１１ｂ側の肩部分に、固定子４２の一端４２ａ側の角が当接するようになっている。また、第１ハウジング１１の内周面において、固定子４２の一端４２ａ側約半分に対応する部分は、固定子４２を圧入固定できるよう、数百μｍの圧入代を持った圧入固定部（焼き嵌め圧入固定部）１１６を形成している。
【００２０】
また、第１ハウジング１１の内周面において、固定子４２の軸方向略中央部に対応する位置から、第１ハウジング１１の開口部１１ｃ側端面１１ａに相当する位置まで、固定子４２の外径よりも０．１ｍｍ程度大きくなるように、切欠部１１７が形成されている。切欠部１１７により、第１ハウジング１１と固定子４２の軸方向他端４２ｂ側半分に対応する部分との間に、隙間Ｃを形成している。
【００２１】
また、図２（ａ）は、第１ハウジング１１を開口部１１ｃ側からみた正面図で、図２（ｂ）は、図２（ａ）のＡ−Ａ断面図である。図２（ａ）に示すように、第１ハウジング１１の端面１１ａの外周部には、この端面１１ａから半径方向外方に向かって伸びる突出部１１１が４ヵ所形成されており、この４つの突出部１１１にボルト孔１１２が設けられ、対角線上の２つの突出部１１１に芯出し用の孔１１３（径は４ｍｍ）が設けられている。
【００２２】
また、同様に、第２ハウジング１２（図１参照）の第１ハウジング１１側端面１２ａの外周部にも、図示しない突出部が４ヵ所形成され、それぞれの突出部において、第１ハウジング１１のボルト孔１１２および孔１１３に対応する部分には、それぞれボルト孔および芯出し用の孔が設けられている。なお、芯出し用の孔１１３は、第１ハウジング１１の形成時において、軸受け孔１１４の中心と孔１１３の中心との間の距離Ｂが所定量（６７ｍｍ）となるように形成される。そして、第２ハウジング１２の芯出し用の上記孔も、第２ハウジング１２の形成時において、軸受け孔１２１の中心と上記孔の中心との間の距離Ｂが上記所定量となるように形成される。
【００２３】
そして、第２ハウジング１２の上記孔と第１ハウジング１１の孔１１３に、この孔１１３の径よりもわずかに小さい図示しないピンを挿嵌した状態で、ボルト締めしている。この結果、芯出しが行われて軸受け孔１２１の中心と軸受け孔１１４の中心とを同軸上に配置させることができ、上記主軸３をスムースに回転させることができる。
【００２４】
以下に、第１ハウジング１１の形成方法、および、固定子４２の組付け方法を図１および図２に基づいて説明する。
まず、一端が閉塞し、他端が開口したコップ状部材を鋳型成形にて形成し、その後、図１および図２に示すような、軸受け孔１１４、リード線取出口１１８、溝１１５、切欠部１１７、ボルト孔１１２、芯出し用の孔１１３を切削加工により形成する。なお、第１ハウジング１１の内周面、具体的に、軸受け孔１１４、圧入固定部１１６、芯出し用の孔１１３の内周面は、研磨加工を施して、加工精度（寸法精度、面粗度等）を上げている。また、第１ハウジング１１の内周面にあたる圧入固定部１１６の内径は、固定子４２の外周面よりもわずかに（数百μｍ程度）小さくなるように形成されている。
【００２５】
そして、第１ハウジング１１に固定子４２を固定する方法としては、焼き嵌めによる方法が一般的となっている。この焼き嵌めでは、まず、この第１ハウジング１１を１７０℃程度の高温の炉中へ約２時間程配置し、第１ハウジング１１を１７０℃程度の高温状態にする。
すると、熱膨張により、第１ハウジング１１の内周面にあたる圧入固定部１１６の内径は、固定子４２の外径よりもわずかに大きくなる。そして、この第１ハウジング１１を炉から取り出して、第１ハウジング１１に室温状態の固定子４２を嵌合して自然冷却する。すると、第１ハウジング１１が収縮するため、固定子４２を締めつけて、圧入固定することができる。
【００２６】
以下に、本実施形態および従来技術におけるひずみの発生する様子を説明する。なお、図１に示すように、第１ハウジング１１の底面部１１ｂには、軸受け孔１１４およびリード線取出口１１８が形成されているが、図３（ａ）、（ｂ）には、底面部１１ｂが閉塞しているとみなして、模式的な半断面図を示している。まず、図３（ｂ）に示す従来技術では、本実施形態でいう隙間Ｃ（図１参照）が設けられておらず、第１ハウジング１１において、固定子４２の軸方向長さに対応する部分が、第１ハウジング１１の圧入固定部１１６となっている。このため、焼き嵌め時において、第１ハウジング１１の圧入固定部１１６が固定子４２をきつく締めつけると、図３（ｂ）中矢印で示すように、固定子４２の外周面の全面から、第１ハウジング１１の半径方向外方に向かって端面１１ａが変形することになる。
【００２７】
すると、第１ハウジング１１は、図４（ａ）に示すような、第１ハウジング１１全体が、半径方向外方に広がるような変形、および、図４（ｂ）に示すような、底面部１１ｂの中心Ｌを支点として上記力方向に回転するような変形をする。この結果、第１ハウジング１１の突出部１１１の位置が、焼き嵌め前に比べて半径方向外方へ大きくずれ、しかも、第１ハウジング１１の端面１１ａが反ってしまう。
【００２８】
これに対して、図３（ａ）に示す本実施形態では、上述のように、第１ハウジング１１と固定子４２との間に隙間Ｃが形成されており、圧入固定部１１６の軸方向長さが従来技術よりも小さいため、焼き嵌め時において、図３（ａ）中矢印で示すように、固定子４２から第１ハウジング１１の半径方向外方に向かって加わる力が従来に比べて小さくなる。
【００２９】
しかも、この圧入固定部１１６が第１ハウジング１１の支点Ｌ側に設けられているので、第１ハウジング１１の底面部１１ｂ（支点）側に力が加わり、第１ハウジング１１の半径方向外方に向かって加わるモーメントが小さくなる。この結果、図４（ａ）および図４（ｂ）に示すような第１ハウジング１１の変形がともに小さくなるので、突出部１１１の半径方向外方への位置ずれを小さくすることができ、かつ、第１ハウジング１１の端面１１ａの反りを小さくすることができる。
【００３０】
以下に、突出部１１１の上記位置ずれ量を検討した実験を、図２および図５に基づいて説明する。
まず、図２において、第１ハウジング１１の端面１１ａから圧入固定部１１６までの軸方向長さをｐ、固定子４２の軸方向長さをｑ、第１ハウジング１１の中心から上記芯出し用の孔１１３の中心までの距離をＢとし、図５に示すグラフの横軸にはｐ／ｑを、縦軸には、焼き嵌め前の距離Ｂと焼き嵌め後の距離Ｂとの変化量を上記位置ずれ量ΔＢとしてプロットした。
【００３１】
上記実験を行うために、まず、距離Ｂを６７ｍｍとし、切欠部１１７の内径を固定子４２の外径より０．１ｍｍ程度大きくし、さらに、圧入固定部１１６と固定子４２との圧入代が数百μｍとなるようにした第１ハウジング１１を所定数形成し、この第１ハウジング１１の１つ１つの長さｐを変えて、実験用の第１ハウジング１１とした。
【００３２】
そして、約１７０℃の炉中に２時間配置して、約１７０℃に加熱された上記第１ハウジング１１に、常温状態の固定子４２を上述のように嵌合して焼き嵌めを行った。その後、３次元測定器を用いて、焼き嵌め後の距離Ｂを測定した。
この結果、図５のグラフに示すように、ｐ／ｑが大きくなるほど、つまり、上記長さｐが大きくなるほど、ΔＢが小さくなることがわかった。そして、ΔＢが８μｍ以下であれば、第２ハウジング１２の軸受け孔１２１と、第１ハウジング１１の軸受け孔１１４との中心がほぼ同軸上にあり、この軸受け孔１２１、１１４に保持される主軸３がスムースに回転できる、ということが、本発明者らの実験により確認されている。従って、図５のグラフにおいて、ｐ／ｑ≧０．３３であれば、ΔＢが８μｍ以下であり、主軸３がスムースに回転できるように、圧縮機を組付けることができる。
【００３３】
なお、隙間Ｃを設けることで、固定子４２の圧入固定力が小さくなるが、実用上問題ないことが確認されている。
（第２の実施形態）
図６（ａ）に示すように、本実施形態では、固定子４２の軸方向一端４２ａ側に設けた、上記第１の実施形態における圧入固定部１１６に加えて、第１ハウジング１１において、固定子４２の軸方向他端４２ｂ側にも副圧入固定部１１６ａを設けている。具体的には、切欠部１１７が形成されることにより、固定子４２の一端４２ａ側に圧入固定部１１６が圧着し、固定子４２の他端４２ｂ側に副圧入固定部１１６ａが圧着し、かつ、この切欠部１１７により、固定子４２と第１ハウジング１１との間に隙間Ｃが形成される。
【００３４】
そして、副圧入固定部１１６ａは、圧入固定部１１６よりも長さが非常に小さく形成されており、具体的に、固定子４２の長さｑが１０３ｍｍのとき、圧入固定部１１６の長さは３０ｍｍ程度、副圧入固定部１１６ａの長さは５ｍｍ程度、隙間Ｃの長さは２５ｍｍ程度である。
以下に、本実施形態および従来技術におけるひずみの発生する様子を図６（ｂ）に基づいて説明する。なお、図６（ｂ）には、第１ハウジング１１の底面部１１ｂが閉塞しているとみなして、模式的な半断面図を示している。
【００３５】
まず、焼き嵌めにより、第１ハウジング１１の圧入固定部１１６部分が、固定子４２から力を受けるので、第１ハウジング１１の端面１１ａ側がわずかに半径方向外方へ広がる。このため、副圧入固定部１１６ａの圧入代は、圧入固定部１１６の圧入代よりも小さくなり、しかも、副圧入固定部１１６ａは圧入固定部１１６よりも軸方向長さが短いので、固定子４２からこの副圧入固定部１１６ａに加わる力は非常に小さい。つまり、この副圧入固定部１１６ａを設けることによる突出部１１１の位置ずれは非常に小さい。
【００３６】
従って、本実施形態によれば、突出部１１１の位置ずれを小さく抑えつつ、固定子４２を第１ハウジング１１内に、より確実に固定することができる。
以下に、上記位置ずれ量を検討した実験を、図６（ａ）および図７に基づいて説明する。
まず、図６（ａ）において、副圧入固定部１１６ａの軸方向長さｒとし、図７に示すグラフの横軸にはｒを、縦軸には、焼き嵌め前の距離Ｂと焼き嵌め後の距離Ｂとの変化量を上記位置ずれ量ΔＢとしてプロットした。
【００３７】
このグラフを得るために、まず、距離Ｂを６７ｍｍとし、切欠部１１７の内径を固定子４２の外径より０．１ｍｍ程度大きくし、圧入固定部１１６と固定子４２との圧入代を数百μｍとし、さらに、第１ハウジング１１の端面１１ａから圧入固定部１１６までの軸方向長さｐをｐ／ｑ＝０．５０となるように固定した第１ハウジング１１を複数形成した。そして、この第１ハウジング１１の副圧入固定部１１６ａの軸方向長さｒを変えて、実験用の第１ハウジング１１とした。
【００３８】
そして、約１７０℃の炉中に２時間配置して、約１７０℃に加熱された実験用の第１ハウジング１１に、常温状態の固定子４２を上述のように嵌合して焼き嵌めを行った。そして、３次元測定器を用いて焼き嵌め後の距離Ｂを測定した。
この結果、図７のグラフに示すように、副圧入固定部１１６ａの長さｒが大きくなるにつれてΔＢも大きくなることがわかった。そして、上述のように、ΔＢが８μｍ以下であれば主軸３がスムースに回転できる、ということが、本発明者らの実験により確認されている。従って、図７のグラフにおいて、ｒ≦２０（ｍｍ）であれば、ΔＢが８μｍ以下であり、主軸３がスムースに回転できるように、圧縮機を組付けることができる。
【００３９】
（第３の実施形態）
図８に示すように、本実施形態では、上記第２の実施形態における圧入固定部１１６、および、副圧入固定部１１６ａに加えて、圧入固定部１１と副圧入固定部１１６ａとの間に、さらに副圧入固定部１１６ｂを設けている。なお、切欠部１１７、１１７が形成されることにより、切欠部１１７、１１７により、固定子４２と第１ハウジング１１との間に隙間Ｃ、Ｃが形成され、かつ、圧入固定部１１６および副圧入固定部１１６ａ、１１６ｂが形成される。
【００４０】
そして、副圧入固定部１１６ａ、１１６ｂは、圧入固定部１１６よりも軸方向長さが非常に短く形成されており、具体的には、圧入固定部１１６の軸方向長さは３０ｍｍ程度、副圧入固定部１１６ａおよび１１６ｂの軸方向長さは５ｍｍ程度であるので固定子４２からこの副圧入固定部１１６ａ、１１６ｂに加わる力は非常に小さい。従って、本実施形態によれば、突出部１１１の位置ずれを小さく抑えつつ、固定子４２を第１ハウジング１１内に、より一層確実に固定することができる。
【００４１】
なお、上記実施形態では、圧入固定部１１６を、主に、第１ハウジング１１の開口部１１ｃから離れた部分に設けているが、本発明はこれに限定されることはなく、固定子４２よりも、軸方向長さの小さい上記圧入固定部１１６を、第１ハウジング１１の開口部１１ｃに近い部分に設けてもよい。この結果、固定子４２から第１ハウジング１１の半径方向外方に加わる力は小さくなるので、第１ハウジング１１の変形を小さく抑えることができる。
【００４２】
また、上記実施形態では、第１ハウジング１１の内周面に切欠部１１７を設けて、第１ハウジング１１と固定子４２との間に隙間Ｃを形成していたが、本発明はこれに限定されることはなく、固定子４２の外周面を切り欠いて、上記隙間Ｃを形成してもよい。
【図面の簡単な説明】
【図１】本発明の第１の実施形態を示す電動スクロール圧縮機の断面図である。
【図２】（ａ）は、固定子を焼き嵌めした第１ハウジングの正面図で、（ｂ）は（ａ）のＡ−Ａ断面図である。
【図３】（ａ）は、第１の実施形態の第１ハウジングの模式的な半断面図で、（ｂ）は従来の第１ハウジングの模式的な半断面図である。
【図４】（ａ）、（ｂ）は、第１ハウジングの変形の様子を示す模式的な半断面図である。
【図５】第１の実施形態における、焼き嵌めによる第１ハウジングの芯出し用孔の位置ずれ量を示すグラフである。
【図６】（ａ）は、第２の実施形態を示す要部断面図で、（ｂ）は、第１ハウジングの変形の様子を示す模式的な半断面図である。
【図７】第２の実施形態における、焼き嵌めによる第１ハウジングの芯出し用孔の位置ずれ量を示すグラフである。
【図８】第３の実施形態を示す要部断面図である。
【図９】従来の電動スクロール圧縮機の断面図である。
【符号の説明】
１…ハウジング、１１…第１ハウジング、１２…第２ハウジング、
１３…第３ハウジング、２…圧縮部、３…主軸（軸部材）、
４…電動機部、４１…回転子、４２…固定子、
１１６…圧入固定部（焼き嵌め圧入固定部）。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a hermetic electric compressor used for a refrigerant compressor or the like in a refrigerating apparatus, and more particularly to an electric scroll compressor or the like having a built-in electric drive source.
[0002]
[Prior art]
FIG. 9 shows a sectional view of a conventional electric scroll compressor. In FIG. 9, reference numeral 1 denotes an aluminum housing that forms a case of the electric scroll compressor. The housing 1 includes a first housing 11, a second housing 12, and a third housing 13. In the third and second housings 13 and 12, a fixed scroll portion 21 and an orbiting scroll portion 22 as the compression portion 2 are provided, and in the first housing 11, the main shaft 3 and the main shaft 3 are driven. A rotor 41 and an iron stator 42 are provided as the electric motor unit 4.
[0003]
The main shaft 3 is rotatably held by a first bearing 5 provided on the second housing 12 and a second bearing 6 provided on the first housing 11. The first housing 11 and the second housing 12, and the second housing 12 and the third housing 13 are respectively fastened and fixed by bolts (not shown). Further, in order to align the centers of the first bearing 5 and the second bearing 6 supporting the main shaft 3, the first housing 11 and the second housing 12 are centered.
[0004]
Specifically, the outer surface of the end surface 11a of the first housing 11 on the second housing 12 side (opening 11c side) and the outer surface of the end surface 12a of the second housing 12 on the first housing 11 side are radially outside these end surfaces. Four protruding portions extending in the direction are integrally formed. These protruding portions are provided with four bolt holes for passing the bolts and two centering holes.
[0005]
The centering holes are provided at predetermined distances from the centers of the bearing holes 121 and 114 and on a diagonal line, and a pin is inserted into the centering hole. Then, by assembling the first and second housings 11 and 12, centering is performed and the centers of the bearing holes 121 and 114 are aligned. This allows the main shaft 3 to rotate smoothly.
[0006]
[Problems to be solved by the invention]
By the way, as a method of fixing the stator 42 to the first housing 11 constituting the compressor, shrink fitting is generally used. Shrink fitting means that the inner diameter of the first housing 11 is made slightly smaller (about several hundred μm) than the outer diameter of the stator 42, and the first housing 11 is heated by setting the first housing 11 to a high temperature state. When the stator 42 at room temperature is fitted into the expanded and thermally expanded first housing 11, the first housing 11 contracts and the stator 42 is tightened and fixed.
[0007]
However, in the prior art, since the first housing 11 is made of aluminum and the stator 42 is made of iron, when the normal-temperature stator 42 is fitted into the thermally expanded first housing 11, the first housing 11 is fixed in the first housing 11. The portion where the stator 42 is fitted can return only to the shape of the stator 42 made of iron having higher rigidity than aluminum, but the portion where the stator 42 is not fitted in the first housing 11 An attempt is made to return to the shape of the first housing 11.
[0008]
Then, a force is applied to the first housing 11 from the entire outer peripheral surface of the stator 42, and the first housing 11 is formed of a cylindrical member having a bottom surface 11b at one end and an opening 11c at the other end. The first housing 11 is greatly deformed in a state where the opening 11c side of the first housing 11 is pushed open. Specifically, the inner diameter of the left side portion of the first housing 11 in FIG. 9 is increased by about 60 μm (0.06 mm). On the other hand, since the second housing 12 does not need to be shrink-fitted and fixed, no deformation occurs. Therefore, if the hole for centering is formed in advance and then shrink-fitted and fixed, the position of the hole of the second housing 12 and the position of the hole of the first housing 11 will be largely shifted.
[0009]
Therefore, after the stator 42 is shrink-fitted and fixed in the first housing 11, the hole for centering must be cut. That is, the hole for centering cannot be formed at the same time when the first housing 11 is formed. Further, after the stator 42 is fixed in the first housing 11, the hole for centering is processed. For this reason, handling is difficult in terms of weight, which complicates the forming process of the electric scroll compressor and increases the cost.
[0010]
The present invention has been made in view of the above points, and has as its object to form a hole for centering at the same time as forming the first housing while suppressing deformation of the first housing after shrink fitting.
[0011]
[Means for Solving the Problems]
The present invention employs the following technical means to achieve the above object.
According to the first to fifth aspects of the present invention, one end of the shaft member (3) is located at the center (114) of the first housing (11), and the other end is located at the center (121) of the second housing (12). A hermetically sealed type which is rotatably supported and has a stator (42) shrink-fitted and fixed to a cylindrical first housing (11) having a bottom portion (11b) at one end and an opening (11c) at the other end. In the electric compressor, a gap (C) is provided in a part of the fitting portion between the first housing (11) and the stator (42) in the axial direction, and the first housing (11) and the stator (42) are provided. The length of the shrink-fit press-fit fixing portions (116, 116a, 116b) in the axial direction is reduced.
[0012]
According to this technical means, at the time of shrink fitting, a part of the outer peripheral surface of the stator (42) is pressed against the inner peripheral surface of the first housing (11). The force applied to the outer side in the radial direction of 11) is smaller than that in the related art. Therefore, in the end surface (11a) on the opening (11c) side of the first housing (11), the outward spread in the radial direction is reduced, and the warpage of the end surface (11a) of the first housing (11) is also reduced. .
[0013]
Therefore, when forming the first housing (11), the centering hole (113) is simultaneously formed in the end surface (11a) of the first housing (11), and then the first housing (11) is shrunk. Since the displacement between the hole (113) of the housing (11) and the hole of the second housing (12) is small, the centering of the first housing (11) and the second housing (12) is performed according to the initial design. It can be done exactly as it is. Therefore, unlike the related art, it is not necessary to form the centering hole (113) after shrink fitting, and the process of forming the hermetic electric compressor is simplified, and the hermetic electric compressor can be formed at low cost. Can be.
[0014]
According to the second aspect of the present invention, the gap (C) is provided on the opening (11c) side of the first housing (11), and the shrink-fit press-fit fixing portion (116) is provided on the first housing (11). Is provided on the side of the bottom surface (11b).
Therefore, at the time of shrink fitting, the force applied from the stator (42) outward in the radial direction of the first housing (11) becomes smaller, so that the radial direction of the end surface (11a) of the first housing (11) is reduced. The outward spread is smaller, and the warpage of the end surface (11a) of the first housing (11) is smaller. Therefore, the displacement between the hole (113) of the first housing (11) and the hole of the second housing (12) can be made smaller, and the centering can be performed more reliably.
[0015]
Further, in the invention according to claim 4, the gap (C) is provided at a portion corresponding to the central portion in the axial direction of the stator (42), and the shrink-fit press-fitting fixing portions (116, 116a, 116b) are provided. And the stator (42) is provided on one end (42a) side in the axial direction and on the other end (42b) side in the axial direction.
According to this technical means, the gap (C) is provided so that the positional deviation between the hole (113) of the first housing (11) and the hole of the second housing (12) is kept small while the stator is kept small. By press-fitting and fixing both ends (42a, 42b) of the (42), the first housing (11) can be more securely fixed in the first housing (11).
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention shown in the drawings will be described.
(1st Embodiment)
FIG. 1 is a sectional view of an electric scroll compressor according to a first embodiment. In FIG. 1, reference numeral 1 denotes a housing which forms a case of the electric scroll compressor. It comprises a second housing 12 and a third housing 13. The first housing 11 and the second housing 12 and the second housing 12 and the third housing 13 are respectively fastened and fixed by bolts (not shown) to form one closed housing 1 as a whole. ing.
[0017]
The housing 1 is made of an aluminum alloy for the purpose of weight reduction, and the first housing 11 is made of a cylindrical member having a bottom surface 11b at one end and an opening 11c at the other end. A fixed scroll portion 21 and an orbiting scroll portion 22 as the compression portion 2 are provided in the second and third housings 12 and 13, and the main shaft 3 and the main shaft 3 are driven in the first housing 11. A rotor 41 as a motor unit 4 and an iron stator 42 are provided.
[0018]
The main shaft (shaft member) 3 is rotatably held by the first bearing 5 provided at the center of the second housing 12 and the second bearing 6 provided at the center of the first housing 11. I have. The first bearing 5 is press-fitted and fixed in a bearing hole 121 formed in the second housing 12, and the second bearing 6 is press-fitted and fixed in a bearing hole 114 formed in the first housing 11. On the inner peripheral surface of the first housing 11, a groove 115 which is slightly notched in a ring shape is formed at a position corresponding to a corner of one end 42 a of the stator 42.
[0019]
By forming the inner diameter of the groove 115 larger than the inner diameter of the bottom portion 11b side portion of the first housing 11, the corner of the one end 42a side of the stator 42 is formed at the shoulder portion of the groove 115 at the bottom portion 11b side. It comes into contact. Further, on the inner peripheral surface of the first housing 11, a portion corresponding to about half of the one end 42 a side of the stator 42 has a press-fit fixing portion (sintering) having a press fitting allowance of several hundred μm so that the stator 42 can be press-fit. A fitting press-fitting fixing portion) 116 is formed.
[0020]
Further, on the inner peripheral surface of the first housing 11, the outer diameter of the stator 42 ranges from a position corresponding to a substantially central portion in the axial direction of the stator 42 to a position corresponding to the end surface 11 a on the opening 11 c side of the first housing 11. Notch 117 is formed so as to be about 0.1 mm larger than that. The notch 117 forms a gap C between the first housing 11 and a portion corresponding to the half on the other end 42b side of the stator 42 in the axial direction.
[0021]
FIG. 2A is a front view of the first housing 11 as viewed from the opening 11c side, and FIG. 2B is a cross-sectional view taken along line AA of FIG. 2A. As shown in FIG. 2A, four protrusions 111 are formed on the outer peripheral portion of the end face 11a of the first housing 11 and extend outward from the end face 11a in the radial direction. A bolt hole 112 is provided in the part 111, and a centering hole 113 (having a diameter of 4 mm) is provided in two diagonally projecting parts 111.
[0022]
Similarly, four protrusions (not shown) are formed on the outer peripheral portion of the end surface 12a on the first housing 11 side of the second housing 12 (see FIG. 1), and the bolts of the first housing 11 are formed at each of the protrusions. Bolt holes and centering holes are provided in portions corresponding to the holes 112 and 113, respectively. The centering hole 113 is formed such that the distance B between the center of the bearing hole 114 and the center of the hole 113 becomes a predetermined amount (67 mm) when the first housing 11 is formed. The hole for centering the second housing 12 is also formed such that the distance B between the center of the bearing hole 121 and the center of the hole becomes the predetermined amount when the second housing 12 is formed. You.
[0023]
Then, a bolt (not shown) slightly smaller than the diameter of the hole 113 is inserted into the hole of the second housing 12 and the hole 113 of the first housing 11, and the bolt is tightened. As a result, the centering is performed, and the center of the bearing hole 121 and the center of the bearing hole 114 can be coaxially arranged, and the main shaft 3 can be smoothly rotated.
[0024]
Hereinafter, a method of forming the first housing 11 and a method of assembling the stator 42 will be described with reference to FIGS.
First, a cup-shaped member having one end closed and the other end opened is formed by molding, and thereafter, as shown in FIGS. 1 and 2, a bearing hole 114, a lead wire outlet 118, a groove 115, a cutout portion. 117, a bolt hole 112, and a centering hole 113 are formed by cutting. The inner peripheral surface of the first housing 11, specifically, the inner peripheral surfaces of the bearing hole 114, the press-fit fixing portion 116, and the centering hole 113 are polished to obtain processing accuracy (dimensional accuracy, surface roughness). Degree). Further, the inner diameter of the press-fit fixing portion 116 corresponding to the inner peripheral surface of the first housing 11 is formed so as to be slightly smaller (about several hundred μm) than the outer peripheral surface of the stator 42.
[0025]
As a method of fixing the stator 42 to the first housing 11, a method of shrink fitting is generally used. In this shrink fitting, first, the first housing 11 is placed in a furnace at a high temperature of about 170 ° C. for about 2 hours to bring the first housing 11 to a high temperature state of about 170 ° C.
Then, due to thermal expansion, the inner diameter of the press-fit fixing portion 116 corresponding to the inner peripheral surface of the first housing 11 becomes slightly larger than the outer diameter of the stator 42. Then, the first housing 11 is taken out of the furnace, and the stator 42 in a room temperature state is fitted to the first housing 11 and naturally cooled. Then, since the first housing 11 contracts, the stator 42 can be tightened and press-fitted and fixed.
[0026]
Hereinafter, the manner in which distortion occurs in the present embodiment and the related art will be described. As shown in FIG. 1, a bearing hole 114 and a lead wire outlet 118 are formed in the bottom surface portion 11 b of the first housing 11, but FIGS. 3A and 3B illustrate the bottom surface portion. 11b shows a schematic half-sectional view, assuming that 11b is closed. First, in the prior art shown in FIG. 3B, the gap C (see FIG. 1) in the present embodiment is not provided, and the first housing 11 has a portion corresponding to the axial length of the stator 42. Are the press-fit fixing portions 116 of the first housing 11. For this reason, at the time of shrink fitting, when the press-fit fixing portion 116 of the first housing 11 tightens the stator 42 tightly, as shown by the arrow in FIG. The end face 11a is deformed radially outward of the housing 11.
[0027]
Then, the first housing 11 is deformed such that the entire first housing 11 expands outward in the radial direction as shown in FIG. 4A, and the bottom portion 11b as shown in FIG. Is deformed so as to rotate in the above-mentioned force direction with the center L of the as a fulcrum. As a result, the position of the protruding portion 111 of the first housing 11 is largely shifted outward in the radial direction as compared with before the shrink fitting, and the end surface 11a of the first housing 11 is warped.
[0028]
On the other hand, in the present embodiment shown in FIG. 3A, as described above, the gap C is formed between the first housing 11 and the stator 42, and the axial length of the press-fit fixing portion 116 is formed. 3A, the force applied from the stator 42 toward the outside in the radial direction of the first housing 11 at the time of shrink fitting as shown by an arrow in FIG. Become.
[0029]
Moreover, since the press-fit fixing portion 116 is provided on the fulcrum L side of the first housing 11, a force is applied to the bottom surface portion 11 b (fulcrum) side of the first housing 11, and the force is applied radially outward of the first housing 11. The applied moment becomes smaller. As a result, since the deformation of the first housing 11 as shown in FIGS. 4A and 4B is reduced, the displacement of the protrusion 111 outward in the radial direction can be reduced, and The warpage of the end surface 11a of the first housing 11 can be reduced.
[0030]
Hereinafter, an experiment in which the above-described displacement amount of the protruding portion 111 is examined will be described with reference to FIGS.
First, in FIG. 2, the axial length from the end face 11 a of the first housing 11 to the press-fit fixing portion 116 is p, the axial length of the stator 42 is q, and the centering of the first housing 11 from the center is performed. The distance to the center of the hole 113 is B, the horizontal axis of the graph shown in FIG. 5 is p / q, and the vertical axis is the amount of change between the distance B before shrink fitting and the distance B after shrink fitting. This is plotted as the positional deviation amount ΔB.
[0031]
In order to perform the above experiment, first, the distance B was set to 67 mm, the inner diameter of the notch 117 was set to be larger than the outer diameter of the stator 42 by about 0.1 mm, and the press-fitting allowance between the press-fit fixing portion 116 and the stator 42 was reduced A predetermined number of first housings 11 each having a thickness of several hundred μm were formed, and the length p of each of the first housings 11 was changed to obtain a first housing 11 for an experiment.
[0032]
Then, it was placed in a furnace at about 170 ° C. for 2 hours, and the normal-temperature stator 42 was fitted and shrink-fitted to the first housing 11 heated to about 170 ° C. as described above. Then, the distance B after shrink fitting was measured using a three-dimensional measuring device.
As a result, as shown in the graph of FIG. 5, it was found that ΔB decreases as p / q increases, that is, as the length p increases. If ΔB is 8 μm or less, the centers of the bearing holes 121 of the second housing 12 and the bearing holes 114 of the first housing 11 are substantially coaxial, and the main shaft 3 held in the bearing holes 121 and 114 Has been confirmed by experiments of the present inventors that can be smoothly rotated. Therefore, in the graph of FIG. 5, if p / q ≧ 0.33, ΔB is 8 μm or less, and the compressor can be assembled so that the main shaft 3 can rotate smoothly.
[0033]
In addition, although the press-fitting fixing force of the stator 42 is reduced by providing the gap C, it has been confirmed that there is no practical problem.
(Second embodiment)
As shown in FIG. 6A, in the present embodiment, in addition to the press-fit fixing portion 116 of the first embodiment, which is provided on the axial one end 42 a side of the stator 42, the first housing 11 is fixed. A sub-press-fit fixing portion 116a is also provided on the other end 42b side of the child 42 in the axial direction. Specifically, by forming the notch portion 117, the press-fit fixing portion 116 is crimped on one end 42a side of the stator 42, the sub-press-fit fixing portion 116a is crimped on the other end 42b side of the stator 42, and The notch 117 forms a gap C between the stator 42 and the first housing 11.
[0034]
The length of the press-fit fixing portion 116a is much smaller than that of the press-fit fixing portion 116. Specifically, when the length q of the stator 42 is 103 mm, the length of the press-fit fixing portion 116 is The length of the sub-press-fit fixing portion 116a is about 5 mm, and the length of the gap C is about 25 mm.
Hereinafter, the manner in which distortion occurs in the present embodiment and the related art will be described with reference to FIG. FIG. 6B is a schematic half cross-sectional view assuming that the bottom surface 11b of the first housing 11 is closed.
[0035]
First, since the press-fit fixing portion 116 of the first housing 11 receives a force from the stator 42 by shrink fitting, the end face 11a side of the first housing 11 slightly spreads radially outward. For this reason, the press-fitting allowance of the sub-press-fitting fixing portion 116a is smaller than the press-fitting allowance of the press-fit fixing portion 116, and the auxiliary press-fitting fixing portion 116a has a shorter axial length than the press-fit fixing portion 116. Therefore, the force applied to the auxiliary press-fit fixing portion 116a is very small. That is, the displacement of the protruding portion 111 due to the provision of the sub-press-fitting fixing portion 116a is extremely small.
[0036]
Therefore, according to the present embodiment, the stator 42 can be more reliably fixed in the first housing 11 while the displacement of the protrusion 111 is kept small.
Hereinafter, an experiment in which the above-described displacement amount is studied will be described with reference to FIGS.
First, in FIG. 6A, the length in the axial direction of the sub-press-fitting fixing portion 116a is defined as r, the horizontal axis of the graph shown in FIG. 7 represents r, and the vertical axis represents the distance B before shrink fitting and the length after shrink fitting. Is plotted as the amount of displacement ΔB.
[0037]
In order to obtain this graph, first, the distance B is set to 67 mm, the inner diameter of the notch 117 is made larger than the outer diameter of the stator 42 by about 0.1 mm, and the press-fitting allowance between the press-fit fixing portion 116 and the stator 42 is several hundreds. μm, and a plurality of first housings 11 were formed in which the axial length p from the end surface 11a of the first housing 11 to the press-fit fixing portion 116 was fixed so that p / q = 0.50. Then, the first housing 11 for experiment was formed by changing the axial length r of the sub-press-fitting fixing portion 116a of the first housing 11.
[0038]
Then, it is placed in a furnace at about 170 ° C. for 2 hours, and the stator 42 at room temperature is fitted and shrink-fitted to the first housing 11 for experiment heated to about 170 ° C. as described above. Was. Then, the distance B after shrink fitting was measured using a three-dimensional measuring device.
As a result, as shown in the graph of FIG. 7, it was found that ΔB increases as the length r of the sub-press-fit fixing portion 116a increases. As described above, it has been confirmed by experiments of the present inventors that the main shaft 3 can rotate smoothly if ΔB is 8 μm or less. Therefore, in the graph of FIG. 7, if r ≦ 20 (mm), ΔB is 8 μm or less, and the compressor can be assembled so that the main shaft 3 can rotate smoothly.
[0039]
(Third embodiment)
As shown in FIG. 8, in the present embodiment, in addition to the press-fit fixing portion 116 and the sub-press-fit fixing portion 116a in the second embodiment, between the press-fit fixing portion 11 and the sub-press-fit fixing portion 116a, Further, a sub-press-fit fixing portion 116b is provided. By forming the cutouts 117, 117, the gaps C, C are formed between the stator 42 and the first housing 11 by the cutouts 117, 117, and the press-fit fixing portion 116 and the sub-press-fit are formed. The fixing portions 116a and 116b are formed.
[0040]
The auxiliary press-fit fixing portions 116a and 116b are formed to have an axial length much shorter than that of the press-fit fixing portion 116. Specifically, the axial length of the press-fit fixing portion 116 is about 30 mm. Since the axial lengths of the fixing portions 116a and 116b are about 5 mm, the force applied from the stator 42 to the auxiliary press-fit fixing portions 116a and 116b is extremely small. Therefore, according to the present embodiment, the stator 42 can be more securely fixed in the first housing 11 while keeping the displacement of the protrusion 111 small.
[0041]
In addition, in the said embodiment, although the press-fit fixing part 116 is mainly provided in the part away from the opening part 11c of the 1st housing 11, this invention is not limited to this, Alternatively, the press-fit fixing portion 116 having a small axial length may be provided in a portion of the first housing 11 close to the opening 11c. As a result, the force applied from the stator 42 to the first housing 11 in the radially outward direction is reduced, so that the deformation of the first housing 11 can be reduced.
[0042]
In the above embodiment, the notch 117 is provided on the inner peripheral surface of the first housing 11 to form the gap C between the first housing 11 and the stator 42. However, the present invention is not limited to this. Instead, the outer circumferential surface of the stator 42 may be cut out to form the gap C.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an electric scroll compressor according to a first embodiment of the present invention.
FIG. 2A is a front view of a first housing in which a stator is shrink-fitted, and FIG. 2B is a sectional view taken along line AA of FIG.
FIG. 3A is a schematic half sectional view of a first housing of the first embodiment, and FIG. 3B is a schematic half sectional view of a conventional first housing.
FIGS. 4A and 4B are schematic half-sectional views showing a state of deformation of a first housing.
FIG. 5 is a graph showing a positional shift amount of a centering hole of a first housing due to shrink fitting in the first embodiment.
FIG. 6A is a sectional view of a main part showing a second embodiment, and FIG. 6B is a schematic half sectional view showing a state of deformation of a first housing.
FIG. 7 is a graph showing the amount of misalignment of the centering hole of the first housing due to shrink fitting in the second embodiment.
FIG. 8 is a sectional view of a main part showing a third embodiment.
FIG. 9 is a sectional view of a conventional electric scroll compressor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... housing, 11 ... 1st housing, 12 ... 2nd housing,
13 ... third housing, 2 ... compression section, 3 ... main shaft (shaft member),
4 ... motor part, 41 ... rotor, 42 ... stator
116 ... press-fit fixing portion (shrink fit press-fit fixing portion).

Claims

A cylindrical first housing (11) having a bottom portion (11b) at one end and an opening (11c) at the other end, and a cylindrical shape adjacent to the opening (11c) side of the first housing (11). A housing (1) comprising at least a second housing (12);
A compression section (2) supported and fixed to the second housing (12) side in the housing (1) and compressing a fluid;
An electric motor section (4) fixed in the first housing (11) and applying a driving force to the compression section (2);
One end is rotatably supported by the center (114) of the first housing (11), and the other end is rotatably supported by the center (121) of the second housing (12). A shaft member (3) for transmitting the driving force of (4) to the compression section (2);
A stator (42) made of an iron-based material that is a magnetic material and fixed along an inner peripheral surface of the first housing (11) is provided in the electric motor unit (4),
The first housing (11) is made of an aluminum alloy material,
A hermetic electric compressor in which the stator (42) is press-fitted and fixed in the first housing (11) by shrink fitting.
A gap (C) is provided at a part of the fitting portion between the first housing (11) and the stator (42) in the axial direction, and the first housing (11) and the stator (42) are The axial length of the shrink-fit press-fit fixing portions (116, 116a, 116b) is shortened .
Further, on the inner peripheral surface of the first housing (11), a groove (115) cut out in a ring shape is provided at a position corresponding to a corner of the end (42a) in the press-fitting direction of the stator (42). A hermetic electric compressor characterized by being formed .

A cylindrical first housing (11) having a bottom portion (11b) at one end and an opening (11c) at the other end, and a cylindrical shape adjacent to the opening (11c) side of the first housing (11). A housing (1) comprising at least a second housing (12);
A compression section (2) supported and fixed to the second housing (12) side in the housing (1) and compressing a fluid;
An electric motor section (4) fixed in the first housing (11) and applying a driving force to the compression section (2);
One end is rotatably supported by the center (114) of the first housing (11), and the other end is rotatably supported by the center (121) of the second housing (12). A shaft member (3) for transmitting the driving force of (4) to the compression section (2);
A stator (42) made of an iron-based material that is a magnetic material and fixed along an inner peripheral surface of the first housing (11) is provided in the electric motor unit (4),
The first housing (11) is made of an aluminum alloy material,
A hermetic electric compressor in which the stator (42) is press-fitted and fixed in the first housing (11) by shrink fitting.
A gap (C) is provided at a part of the fitting portion between the first housing (11) and the stator (42) in the axial direction, and the first housing (11) and the stator (42) are The axial length of the shrink-fit press-fit fixing portions (116, 116a, 116b) is shortened.
The gap (C) is provided on the opening (11c) side of the first housing (11),
The baked press fit fixing portion (116), said bottom portion (11b) you characterized in that provided on the side hermetic electric compressor of the first housing (11).

The hermetic electric compressor according to claim 2,
The axial length from the end surface (11a) of the first housing (11) on the opening (11c) side to the shrink-fit press-fit fixing portion (116) is p, and the axial length of the stator (42) is A closed-type electric compressor, wherein q is p / q ≧ 0.33.

A cylindrical first housing (11) having a bottom portion (11b) at one end and an opening (11c) at the other end, and a cylindrical shape adjacent to the opening (11c) side of the first housing (11). A housing (1) comprising at least a second housing (12);
A compression section (2) supported and fixed to the second housing (12) side in the housing (1) and compressing a fluid;
An electric motor section (4) fixed in the first housing (11) and applying a driving force to the compression section (2);
One end is rotatably supported by the center (114) of the first housing (11), and the other end is rotatably supported by the center (121) of the second housing (12). A shaft member (3) for transmitting the driving force of (4) to the compression section (2);
A stator (42) made of an iron-based material that is a magnetic material and fixed along an inner peripheral surface of the first housing (11) is provided in the electric motor unit (4),
The first housing (11) is made of an aluminum alloy material,
A hermetic electric compressor in which the stator (42) is press-fitted and fixed in the first housing (11) by shrink fitting.
A gap (C) is provided at a part of the fitting portion between the first housing (11) and the stator (42) in the axial direction, and the first housing (11) and the stator (42) are The axial length of the shrink-fit press-fit fixing portions (116, 116a, 116b) is shortened.
The gap (C) is provided at a portion corresponding to an axial center portion of the stator (42),
The shrink-fit press-fit fixing portions (116, 116a, 116b) are provided on one end (42a) side in the axial direction and the other end (42b) in the axial direction of the stator (42). that the hermetic electric compressor.

The hermetic electric compressor according to claim 4,
The axial length from the end surface (11a) of the first housing (11) on the opening (11c) side to the shrink-fit press-fit fixing portion (116) on the one end (42a) side is p, and the stator ( Assuming that the axial length of 42) is q and the axial length of the shrink fit fixing portion (116a) on the other end (42b) side is r, p / q ≧ 0.50, r ≦ 20 (mm) ) A hermetic electric compressor.