JP4449151B2

JP4449151B2 - Hermetic electric compressor and refrigeration system

Info

Publication number: JP4449151B2
Application number: JP2000109375A
Authority: JP
Inventors: 章浩野末; 寿和境
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 2000-04-11
Filing date: 2000-04-11
Publication date: 2010-04-14
Anticipated expiration: 2020-04-11
Also published as: JP2001295765A

Description

【０００１】
【発明の属する技術分野】
本発明は、空気調和器や冷蔵庫等の冷凍空調分野の冷媒圧縮式冷凍システムに適用される密閉型電動圧縮機および冷凍装置に関するものである。
【０００２】
【従来の技術】
現在、冷凍システムの冷媒としては、フロン系の冷媒が主として使われているが、オゾン層保護、地球温暖化防止の観点より冷凍システムの冷媒として、炭化水素系冷媒等の自然冷媒が検討されている。自然系冷媒の中でも、アンモニア冷媒は能力が高く、コストも安いことから注目されている。
【０００３】
しかしながら、アンモニア単独の冷媒あるいはアンモニアを混合した混合冷媒を効率の高い冷媒圧縮式冷凍システムに用いる場合、その金属材料や絶縁材料に対する耐久性が問題になる。
【０００４】
現在、アンモニア冷媒を用いた密閉型圧縮機の気密端子として、実公平６−２９０１１号公報がある。図５を用いて説明すると、電動機が封入されている密閉容器２００に穿設した開口２０１に、絶縁性樹脂からなるパッキン２０２を介して電気的絶縁のためフランジ付きの絶縁部材２０３を貫通させ、前記絶縁性部材２０３のフランジ部２０４を前記密閉容器２００に締め付けボルト２０５によって締結固定されているとともに、前記密閉容器２００内に配設されているモータ等の電気機器（図示せず）と、前記密閉容器２００の大気側での外部配線（図示せず）とに、電気的に接続するための端子ピン２０６が前記絶縁性部材２０３の中心を気密的に貫通して大気側に導出されており、その導出部を前記外部配線との接続のための接続部位２０７として機能させている。
【０００５】
ここで、前記端子ピン２０６は、アンモニアに曝される密閉容器２００内の部位２０８と前記密閉容器２００の大気側に導出される部位２０７とに分けて、そのピン材に例えばアルミニウム又は銅のいずれかの金属材料を用いるか、あるいは銅とアルミニウムの異種金属材料を継足して用いることも可能である。
【０００６】
ところで、密閉容器内の冷媒や油中には容器の溶接の際やピストンの摺動摩耗等で生ずる鉄粉や銅粉等の金属粉が混在している。そして、これらの金属粉は冷媒によって容器内の各部に運ばれて付着し、気密端子のガラス表面にも付着する。ガラス表面に付着する金属粉の量が多くなり、しかも圧縮機の再始動時等に端子ピンに大きな電圧が印可されると、付着した金属粉を介して端子ピンと筒状部の間でスパークが飛び、漏電や端子の破損といった事故になる。
【０００７】
フロン系冷媒においては上記の問題に対処する方策として特開６２−２７１９７５号公報に記載されているものがある。
【０００８】
図６と図７を用いて説明すると、１０８は透孔、１１１は保護カバーで、２５０〜３００μｍ程度のポリエチレンテレフタレート（以下ＰＥＴと称す）より絞り形成された円板形のものである。１１２は外周の折り返し部、１１３は中央の小孔と一体化した筒部、筒部１１３は、膨出部１１６，大径孔１１７，小径孔１１８を有している。
【０００９】
この保護カバー１１１の折り返し部１１２の外径は前記金属基板１０３の内径より僅かに大きく、膨出部１１６の内径は筒状部１０５の外径より僅かに小さく、また、大径孔１１７の直径は筒状部１０５より大きく、小径孔１１８の直径は端子ピン１０７の外径より僅かに小さくなるように形成されている。そして、この保護カバー１１１は、図７に示すように小径孔１１８を端子ピン１０７に、折り返し部１１２を金属基板１０３の内側に圧入状態に挿入することにより気密端子１００に装着され、気密端子１００は密閉容器１０２に溶接される。
【００１０】
ここで、気密端子１００に装着された保護カバー１１１は上述した寸法関係から、小径孔１１８と端子ピン１０７の間、膨出部１１６と筒状部１０５の間、及び折り返し部１１２と金属基板１０３の間で密着状態になるとともに、ガラス１０６の表面との間で隙間１２０が形成された状態となる。このように構成された密閉型電動圧縮機の気密端子１００において、ＰＥＴからなる保護カバー１１１は、ガラス１０６の表面を完全に覆っているだけでなく、この保護カバー１１１とガラス１０６表面の間には隙間１２０が形成されているため、電気力線の最も強いガラス１０６の表面から保護カバー１１１をある程度離しておくことができ、筒状部１０５付近で保護カバー１１１に吸着される金属粉の量をも大幅に低減できることから、端子ピン１０７と金属基板１０３との間で生ずるスパークを防止することができる。
【００１１】
【発明が解決しようとする課題】
しかしながら、上記従来の構成では、アンモニアにより保護カバーのＰＥＴが腐蝕・脱落することで、ガラスに金属粉が付着し、金属基板とスパークがおこる問題がある。
【００１２】
また、アンモニアは金属特に水分を含むとアンモニアは銅及び銅合金を著しく腐蝕させ、また、鉄やアルミニウム等の腐蝕も完全には抑制できず、耐久性が劣る。
【００１３】
本発明は、アンモニアを含む冷媒を用いた場合でも、ガラスに金属粉が付着せず、端子ピンと金属外環との間で生ずるスパークを防止し、漏電や端子の破損を防ぐ効果を有し、耐久性を向上した気密端子を備えた密閉型電動圧縮機を提供することを目的とする。
【００１４】
【課題を解決するための手段】
そこで本発明の密閉型電動圧縮機は、密閉容器内に電動要素と少なくともアンモニアを含む冷媒を圧縮する圧縮要素を有する密閉型電動圧縮機で、金属外環の密閉容器内側に、端子ピンの外周面、筒状部の外周面、及び金属外環の内周面に密着されるような、ポリフェニレンサルファイド，ポリサルホン，ポリエーテルサルホン，ポリエーテルエーテルケトン，ポリエーテルイミド，ポリアミドイミドの群より少なくとも１種以上を用いて形成された保護カバーが装着され、気密端子が密閉容器内の気相冷媒雰囲気に設置されることを特徴とするものである。あるいは、冷媒は、炭化水素とアンモニアを主成分とし、アンモニアの組成比が１〜２０重量％であり、運転中の含有水分量が１００重量ｐｐｍ以下であることを特徴とする。
【００１５】
この発明によれば、アンモニアを含む冷媒を用いた場合でも、気密端子の保護カバーが溶解・脱落しないためガラスに金属粉が付着せず、端子ピンと金属外環との間でスパークを防止し、漏電や端子の破損を防ぐとともにアンモニアとの耐久性や材料適合性に優れる効果を有する気密端子を備えた密閉型電動圧縮機を提供することが可能になる。
【００１６】
【発明の実施の形態】
本発明の請求項１に記載の発明は密閉容器内に電動要素とアンモニアと炭化水素を主成分とし、アンモニアの組成比が１〜２０重量％であり、かつ、運転中の冷媒の含有水分量が１００重量ｐｐｍ以下である冷媒を圧縮する圧縮要素を有する密閉型電動圧縮機において、透孔と前記透孔を囲む筒状部とを有する金属外環を備え、前記金属外環の透孔にガラスを介して表面は被膜を設けることなく銅あるいは銅を含む合金で形成される端子ピンを気密絶縁的に封着して成り、前記金属外環の前記密閉容器内側に、前記端子ピンの外周面、前記筒状部の外周面、及び前記金属外環の内周面に密着されるような、ポリフェニレンサルファイド，ポリサルホン，ポリエーテルサルホン，ポリエーテルエーテルケトン，ポリエーテルイミド，ポリアミドイミドの群より少なくとも１種以上を用いて形成された保護カバーが装着され、前記密閉容器を貫通して該容器に固着された気密端子を用いることを特徴とする密閉型電動圧縮機であって、アンモニアを含む冷媒を用いた場合でも、保護カバーが溶解・脱落しないためガラスに金属粉が付着せず、端子ピンと金属外環との間で生ずるスパークを防止し、漏電や端子の破損を防ぐという作用を有する。
また、アンモニア比率を下げることで、アンモニアの腐食性が低下し、気密端子材料の耐久性が向上するという作用を有する。
また、含有水分量が１００重量ｐｐｍ以下であることでアンモニアの腐食性が低減され、端子ピン材料の耐久性が向上するという作用を有する。
また、耐久性に優れ、かつ通電時の電気的損失が少ないという作用を有する。
【００１７】
本発明の請求項２に記載の発明は、請求項１記載の密閉型電動圧縮機において、前記気密端子が前記密閉容器内の気相冷媒雰囲気に設置されることを特徴とする密閉型電動圧縮機であって、気密端子の端子ピンが液冷媒や冷凍機油により短絡を防止し、冷媒密度が小さい気相冷媒雰囲気に密閉端子を設置することで漏電や端子の破損を防ぐという作用を有する。
【００１８】
本発明の請求項３に記載の発明は、請求項２記載の密閉型電動圧縮機において、前記密閉容器内を、冷媒が送り込まれる吸入圧雰囲気となる低圧空間としたことを特徴とする密閉型電動圧縮機であって、低圧空間にすることで気相冷媒密度がさらに低下し、漏電や端子の破損の安全性を高めるという作用を有する。
【００２２】
本発明の請求項４に記載の発明は、冷媒を圧縮，凝縮，膨張，蒸発させる冷凍サイクルを形成する冷凍装置において、請求項１，請求項２，請求項３のいずれか１項記載の密閉型電動圧縮機を用いることを特徴とする冷凍装置であって、アンモニアを含む冷媒を用いた場合でも、保護カバーが溶解・脱落しないためガラスに金属粉が付着せず、端子ピンと金属外環との間で生ずるスパークを防止し、漏電や端子の破損を防ぎ、安全性を向上した冷凍装置を提供するという作用を有する。
【００２３】
【実施例】
以下、図１〜４、表１〜２を用いて、本発明による圧縮機および冷凍装置の実施例について説明する。
【００２４】
図１は本発明の具体的実施例における密閉型電動圧縮機の気密端子の断面図である。図１において、２はアンモニアが１０重量％、プロパンが９０重量％からなる冷媒を圧縮する密閉型電動圧縮機２１の密閉容器で、気密端子１０は密閉容器２に溶接されている。気密端子１０は３個の透孔８と前記透孔８を各々囲む筒状部５とを有する金属基板３を備え、前記金属基板３の各々の透孔８に端子ピン７をガラス６を介して気密絶縁的に封着する。１はポリフェニレンサルファイドを射出成形して成る保護カバーであり、外周の折り返し部１２と、膨出部１６及び大径孔１７、小径孔１８を有する筒部９と、中央の小孔とが一体的に形成されている。ここで、この保護カバー１の折り返し部１２の外径は金属基板３の内径より僅かに大きく、膨出部１６の内径は筒状部５の外径より僅かに小さく、また、大径孔１７の直径は筒状部５より大きく、小径１８の直径は銅で作られた端子ピン７の外径より僅かに小さくなるよう形成されている。
【００２５】
前記保護カバー１は図２に示すように、小径孔１８を端子ピン７に、折り返し部１２を金属基板３の内側に圧入状態に挿入することにより気密端子１０に装着される。
【００２６】
また、図３は本発明の実施例の密閉型電動圧縮機の縦断面図で、図３において２１は密閉型電動圧縮機を示し、密閉容器２の中に電動機２２および圧縮機２３が収納されており、２４は気相冷媒、２５は４０℃粘度４６ｍｍ²／ｓのアルキルベンゼン系合成油からなる冷凍機油である。図３より、前記気密端子１０は、気相冷媒２４中に設けられている。
【００２７】
ここで、気密端子１０に装着された保護カバー１は上述した寸法関係から、小径孔１８と端子ピン７の間、膨出部１６と筒状部５の間、及び折り返し部１２と金属基板３の間で密着状態になるとともに、ガラス６の表面との間で隙間２０が形成された状態となる。このように構成された密閉型電動圧縮機の気密端子１０において、保護カバー１は、ガラス６の表面を完全に覆っているだけでなく、この保護カバー１とガラス６表面の間には隙間２０が形成されているため、電気力線の最も強いガラス６の表面から保護カバー１をある程度離しておくことができ、筒状部５付近で保護カバー１に吸着される金属粉の量をも大幅に低減できることから、端子ピン７と金属基板３との間で生ずるスパークを防止することができる。
【００２８】
また、気密端子１０を前記密閉容器２内の気相冷媒２４中に設置することで、電気的安全性を向上させる。なお、密閉容器内が吸入圧力雰囲気になる低圧シェルタイプの密閉型電動圧縮機であれば、気密端子が設置される気相冷媒密度はさらに低下し、安全性がさらに向上する。
【００２９】
この構成で選択された保護カバー１の材料仕様は、以下の試験を行うことで選択された。ガラス封管あるいは金属容器に冷媒、冷凍機油、供試材料を入れ、１３０〜１４０℃、１６８〜３３６ｈの恒温状態で維持し、供試材料の外観と強度の劣化を指標に、冷媒と供試材料の適合性を評価した。
【００３０】
【表１】

【００３１】
供試材料と試験結果を（表１）に示す。（表１）において、冷媒はアンモニア（表中記号：ＮＨ₃）１００％の純冷媒、アンモニア（表中記号：ＮＨ₃）１０重量％とプロパン（表中記号：Ｃ₃Ｈ₈）９０重量％の混合冷媒を供試し、冷凍機油は４０℃粘度４６ｍｍ²／ｓアルキルベンゼン性合成油（表中記号：ＨＡＢ４６）を供試した。プラスチック材料はポリフェニレンサルファイド（表中記号：ＰＰＳ）、ポリサルホン（表中記号：ＰＳＦ），ポリエーテルサルホン（表中記号：ＰＥＳ）、ポリエーテルエーテルケトン（表中記号：ＰＥＥＫ），ポリエーテルイミド（表中記号：ＰＥＩ），ポリアミドイミド（表中記号：ＰＡＩ），ポリエチレンテレフタレート（表中記号：ＰＥＴ），ポリエチレンナフタレート（表中記号：ＰＥＮ）を用いた。また、劣化レベルは目視によるプラスチック試験片の変色や冷凍機油の濁りの比較、強度変化から相対的に評価し、良好な順に◎，○，△，×，××の記号で表した。
【００３２】
（表１）に示した試験結果より、ポリエチレンテレフタレートやポリエチレンナフタレートといった分子構造内にエステル結合を有するプラスチック材料は耐アンモニア性がなく、濁り、強度低下とも大きい。この結果、ポリフェニレンサルファイド，ポリサルホン，ポリエーテルサルホン，ポリエーテルエーテルケトン，ポリエーテルイミド，ポリアミドイミドは耐アンモニア性に優れることがわかり、保護カバー材料として適していることがわかり、従って、保護カバー１の材料としては、これらの材料を単独あるいは複合させたものが適している。
【００３３】
また、（表１）に示した試験結果より、冷媒中のアンモニア濃度を低減させることで、各プラスチック材料の劣化も低減されており、耐久性の向上が図れた。
【００３４】
一方、冷媒中の含有水分量と金属材料に対する影響については、以下の試験を行うことで確認された。ガラス封管に冷媒，冷凍機油，供試材料および水分を入れ、１３０〜１７５℃、１６８ｈの恒温状態で維持し、供試材料の外観と油中金属量を指標に、冷媒と金属材料の適合性を評価した。
【００３５】
【表２】

【００３６】
試験条件と適合性の評価結果を表２に示す。（表２）から特に水分量が５００重量ｐｐｍ以上では、劣化が激しく、１００重量ｐｐｍ以下では抑制されることがわかった。
【００３７】
また、端子ピン７は鉄，ニッケル，クロムの合金や銅，銅合金で構成されたり、これらをメッキ等で被覆されたものが用いられる。特に、銅や銅合金は比抵抗が小さく、クロムが１８重量％、ニッケルが８重量％、鉄が７４重量％の合金の比抵抗が７２μΩｃｍに対し、例えば銅は１．７２μΩｃｍ、真鍮（銅が７０重量％、亜鉛が３０重量％）は５〜７μΩｃｍである。冷媒中の水分量を１００重量ｐｐｍにすることで、アンモニアを含む冷媒中でも導電性に優れた銅や銅合金を用いることができ、通電時の電気的損失が抑えられる。
【００３８】
また、前記密閉型電動圧縮機を用いた冷凍サイクルの模式図を図４に示す。図４で２１は前記密閉型電動圧縮機で、２６は凝縮器、２７はキャピラリチューブからなる減圧器、２８は蒸発器である。冷凍装置を用いれば、アンモニアを含む冷媒を用いた場合でも、保護カバーが溶解・脱落しないためガラスに金属粉が付着せず、端子ピンと金属外環との間で生ずるスパークを防止し、漏電や端子の破損を防ぎ、安全性を向上する。
【００３９】
前記の構成を持つ本実施例の冷凍装置を密閉型電動圧縮機の冷凍機油温度９０℃、高圧側圧力２．７２ＭＰａ、低圧側圧力０．３５ＭＰａの過負荷条件で約１カ月連続運転した結果、構成材料に顕著な劣化は認められず十分な耐久性があることが確認できた。
【００４０】
本実施例では保護カバー材料にポリフェニレンサルファイドを用いたが、（表１）の結果から、ポリフェニレンサルファイド，ポリサルホン，ポリエーテルサルホン，ポリエーテルエーテルケトン，ポリエーテルイミド，ポリアミドイミドを単独あるいは複合させたものを用いても同様の結果が得られると期待できる。
【００４１】
また、端子ピンの材料には銅を用いたが（表２）の結果から、真鍮などの銅を含む導電性に優れた合金でも耐アンモニア性があり、同様の結果が得られると期待できる。
【００４２】
【発明の効果】
以上のようにこの発明によれば、アンモニアを含む冷媒を用いた場合でも、気密端子の保護カバーが溶解・脱落しないためガラスに金属粉が付着せず、端子ピンと金属外環との間でスパークを防止し、漏電や端子の破損を防ぐとともにアンモニアとの耐久性や材料適合性に優れる効果を有する気密端子を備えた密閉型電動圧縮機を提供することが可能になる。
【図面の簡単な説明】
【図１】本発明の実施例における密閉型電動圧縮機の気密端子の断面図
【図２】本発明の実施例における密閉型電動圧縮機の保護カバーを気密端子に装着するところを示す、気密端子の断面図
【図３】本発明の実施例における密閉型電動圧縮機の縦断面図
【図４】本発明の実施例における冷凍装置の模式図
【図５】従来のアンモニア冷媒を圧縮する密閉型電動圧縮機の密閉端子の断面図
【図６】従来のフロン系冷媒を圧縮する密閉型電動圧縮機の密閉端子の断面図
【図７】従来のフロン系冷媒を圧縮する密閉型電動圧縮機の保護カバーを気密端子に装着するところを示す、気密端子の断面図
【符号の説明】
１保護カバー
２密閉容器
６ガラス
７端子ピン
１０気密端子
２１密閉型電動圧縮機
２４気相冷媒
２５冷凍機油
２６凝縮器
２７減圧器
２８蒸発器[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hermetic electric compressor and a refrigeration apparatus applied to a refrigerant compression refrigeration system in the field of refrigeration and air conditioning such as an air conditioner and a refrigerator.
[0002]
[Prior art]
Currently, chlorofluorocarbon refrigerants are mainly used as refrigerants for refrigeration systems, but natural refrigerants such as hydrocarbon refrigerants have been studied as refrigerants for refrigeration systems from the viewpoint of protecting the ozone layer and preventing global warming. Yes. Among natural refrigerants, ammonia refrigerant is attracting attention because of its high capacity and low cost.
[0003]
However, when an ammonia-only refrigerant or a mixed refrigerant mixed with ammonia is used in a highly efficient refrigerant compression refrigeration system, the durability of the metal material and the insulating material becomes a problem.
[0004]
Currently, Japanese Utility Model Publication No. 6-29011 is known as an airtight terminal of a hermetic compressor using an ammonia refrigerant. Referring to FIG. 5, a flanged insulating member 203 is passed through an opening 201 formed in an airtight container 200 in which an electric motor is sealed through a packing 202 made of an insulating resin for electrical insulation. The flange portion 204 of the insulating member 203 is fastened and fixed to the sealed container 200 by fastening bolts 205, and an electric device (not shown) such as a motor disposed in the sealed container 200; A terminal pin 206 for electrical connection to an external wiring (not shown) on the atmosphere side of the sealed container 200 is led through the center of the insulating member 203 to the atmosphere side. The lead-out portion functions as a connection portion 207 for connection with the external wiring.
[0005]
Here, the terminal pin 206 is divided into a part 208 in the sealed container 200 exposed to ammonia and a part 207 led out to the atmosphere side of the sealed container 200, and the pin material is made of, for example, aluminum or copper. These metal materials can be used, or different metal materials of copper and aluminum can be used in succession.
[0006]
By the way, metal powder such as iron powder and copper powder generated during welding of the container and sliding wear of the piston is mixed in the refrigerant and oil in the sealed container. These metal powders are transported and adhered to each part in the container by the refrigerant, and also adhere to the glass surface of the airtight terminal. When the amount of metal powder adhering to the glass surface increases and a large voltage is applied to the terminal pin when the compressor is restarted, a spark is generated between the terminal pin and the cylindrical portion via the adhering metal powder. It will cause accidents such as flying, electric leakage and damage to terminals.
[0007]
As a measure for coping with the above problems, there is a fluorocarbon refrigerant described in Japanese Patent Application Laid-Open No. 62-271975.
[0008]
Referring to FIGS. 6 and 7, 108 is a through hole, 111 is a protective cover, and has a disk shape drawn from polyethylene terephthalate (hereinafter referred to as PET) having a thickness of about 250 to 300 μm. Reference numeral 112 denotes an outer periphery turning portion, 113 denotes a cylindrical portion integrated with a small hole at the center, and the cylindrical portion 113 includes a bulging portion 116, a large diameter hole 117, and a small diameter hole 118.
[0009]
The outer diameter of the folded portion 112 of the protective cover 111 is slightly larger than the inner diameter of the metal substrate 103, the inner diameter of the bulging portion 116 is slightly smaller than the outer diameter of the cylindrical portion 105, and the diameter of the large-diameter hole 117. Is larger than the cylindrical portion 105, and the diameter of the small diameter hole 118 is formed to be slightly smaller than the outer diameter of the terminal pin 107. As shown in FIG. 7, the protective cover 111 is attached to the airtight terminal 100 by inserting the small diameter hole 118 into the terminal pin 107 and the folded portion 112 inside the metal substrate 103 in a press-fit state. Is welded to the sealed container 102.
[0010]
Here, the protective cover 111 attached to the airtight terminal 100 has a dimensional relationship as described above, between the small diameter hole 118 and the terminal pin 107, between the bulging portion 116 and the cylindrical portion 105, and between the folded portion 112 and the metal substrate 103. Between the glass 106 and the surface of the glass 106 is formed. In the hermetic terminal 100 of the hermetic electric compressor configured as described above, the protective cover 111 made of PET not only completely covers the surface of the glass 106, but also between the protective cover 111 and the glass 106 surface. Since the gap 120 is formed, the protective cover 111 can be separated to some extent from the surface of the glass 106 having the strongest lines of electric force, and the amount of metal powder adsorbed to the protective cover 111 near the cylindrical portion 105 Therefore, sparks generated between the terminal pins 107 and the metal substrate 103 can be prevented.
[0011]
[Problems to be solved by the invention]
However, in the above conventional configuration, there is a problem that the metal powder adheres to the glass and sparks with the metal substrate because the protective cover PET is corroded and dropped by ammonia.
[0012]
In addition, when ammonia contains a metal, particularly moisture, ammonia significantly corrodes copper and copper alloy, and corrosion of iron, aluminum, etc. cannot be completely suppressed, resulting in poor durability.
[0013]
Even when a refrigerant containing ammonia is used, the present invention has the effect of preventing sparks generated between the terminal pin and the metal outer ring without causing metal powder to adhere to the glass, and preventing leakage and damage to the terminal, It is an object of the present invention to provide a hermetic electric compressor having an airtight terminal with improved durability.
[0014]
[Means for Solving the Problems]
Therefore, the hermetic electric compressor of the present invention is a hermetic electric compressor having a compression element that compresses an electric element and a refrigerant containing at least ammonia in the hermetic container, and the outer periphery of the terminal pin is disposed inside the hermetic container of the metal outer ring. At least one member selected from the group consisting of polyphenylene sulfide, polysulfone, polyethersulfone, polyetheretherketone, polyetherimide, and polyamideimide that are in close contact with the surface, the outer peripheral surface of the cylindrical portion, and the inner peripheral surface of the metal outer ring. A protective cover formed using seeds or more is attached, and an airtight terminal is installed in a gas-phase refrigerant atmosphere in a sealed container. Alternatively, the refrigerant is characterized in that the main component is hydrocarbon and ammonia, the composition ratio of ammonia is 1 to 20% by weight, and the water content during operation is 100 ppm by weight or less.
[0015]
According to this invention, even when a refrigerant containing ammonia is used, the protective cover of the hermetic terminal does not melt / drop off, so that the metal powder does not adhere to the glass, preventing sparks between the terminal pin and the metal outer ring, It becomes possible to provide a hermetic type electric compressor provided with an airtight terminal which has an effect of preventing leakage and breakage of terminals and being excellent in durability and material compatibility with ammonia.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
The invention according to claim 1 of the present invention is mainly composed of an electric element, ammonia and hydrocarbon in a sealed container, the composition ratio of ammonia is 1 to 20% by weight, and the moisture content of the refrigerant during operation A hermetic electric compressor having a compression element that compresses a refrigerant having a weight of 100 ppm by weight or less includes a metal outer ring having a through hole and a cylindrical portion surrounding the through hole, and the metal outer ring has a through hole. The surface of the terminal pin is formed by sealing a terminal pin formed of copper or an alloy containing copper without providing a coating through the glass in an airtight insulating manner. Polyphenylene sulfide, polysulfone, polyethersulfone, polyetheretherketone, polyetherimide, polyamide, which are in close contact with the surface, the outer peripheral surface of the cylindrical portion, and the inner peripheral surface of the metal outer ring A hermetic electric compressor, wherein a protective cover formed using at least one kind from a group of amides is mounted, and an airtight terminal that penetrates the hermetic container and is fixed to the container is used. Even when a refrigerant containing ammonia is used, the protective cover does not melt or drop off, so that no metal powder adheres to the glass, preventing sparking between the terminal pin and the metal outer ring, and preventing leakage and damage to the terminal. It has the action.
Moreover, by reducing the ammonia ratio, the corrosiveness of ammonia is lowered, and the durability of the airtight terminal material is improved.
Further, when the water content is 100 ppm by weight or less, the corrosiveness of ammonia is reduced, and the durability of the terminal pin material is improved.
Moreover, it has the effect | action that it is excellent in durability and there is little electrical loss at the time of electricity supply.
[0017]
According to a second aspect of the present invention, in the hermetic electric compressor according to the first aspect, the hermetic terminal is installed in a gas-phase refrigerant atmosphere in the hermetic container. The terminal pin of the airtight terminal has an effect of preventing a short circuit by liquid refrigerant or refrigeration oil, and preventing leakage and damage of the terminal by installing a hermetic terminal in a gas-phase refrigerant atmosphere having a low refrigerant density.
[0018]
According to a third aspect of the present invention, in the hermetic electric compressor according to the second aspect, the hermetic container is a low-pressure space that serves as a suction pressure atmosphere into which a refrigerant is fed. The electric compressor has an effect of further reducing the density of the gas-phase refrigerant by making it a low-pressure space, and improving the safety of electric leakage and terminal breakage.
[0022]
The invention according to claim 4 of the present invention, compresses refrigerant, condensation, expansion, in a refrigeration apparatus for forming a refrigeration cycle to evaporate, according to claim 1, claim 2, sealing of any one of claims 3 A refrigeration system characterized by using a type electric compressor, and even when a refrigerant containing ammonia is used, the protective cover does not melt or fall off, so that metal powder does not adhere to the glass, and the terminal pin and the metal outer ring It has the effect of preventing sparks generated between them, preventing leakage and breakage of terminals, and providing a refrigeration apparatus with improved safety.
[0023]
【Example】
Hereinafter, the Example of the compressor and freezing apparatus by this invention is described using FIGS. 1-4 and Tables 1-2.
[0024]
FIG. 1 is a cross-sectional view of a hermetic terminal of a hermetic electric compressor according to a specific embodiment of the present invention. In FIG. 1, 2 is a sealed container of a hermetic electric compressor 21 that compresses a refrigerant composed of 10 wt% ammonia and 90 wt% propane, and the hermetic terminal 10 is welded to the sealed container 2. The hermetic terminal 10 includes a metal substrate 3 having three through-holes 8 and a cylindrical portion 5 surrounding each of the through-holes 8, and terminal pins 7 are inserted into the through-holes 8 of the metal substrate 3 through glass 6. Seal in an airtight and insulating manner. Reference numeral 1 denotes a protective cover formed by injection molding of polyphenylene sulfide, and the outer periphery folded portion 12, the bulging portion 16, the cylindrical portion 9 having the large diameter hole 17 and the small diameter hole 18, and the central small hole are integrated. Is formed. Here, the outer diameter of the folded portion 12 of the protective cover 1 is slightly larger than the inner diameter of the metal substrate 3, the inner diameter of the bulging portion 16 is slightly smaller than the outer diameter of the cylindrical portion 5, and the large-diameter hole 17. Is larger than the cylindrical portion 5, and the diameter of the small diameter 18 is formed to be slightly smaller than the outer diameter of the terminal pin 7 made of copper.
[0025]
As shown in FIG. 2, the protective cover 1 is attached to the hermetic terminal 10 by inserting the small diameter hole 18 into the terminal pin 7 and the folded portion 12 into the metal substrate 3 in a press-fitted state.
[0026]
3 is a longitudinal sectional view of the hermetic electric compressor according to the embodiment of the present invention. In FIG. 3, 21 indicates a hermetic electric compressor, and the motor 22 and the compressor 23 are accommodated in the hermetic container 2. 24 is a gas phase refrigerant, and 25 is a refrigerating machine oil made of an alkylbenzene-based synthetic oil having a viscosity of 46 mm ² / s at 40 ° C. As shown in FIG. 3, the airtight terminal 10 is provided in the gas-phase refrigerant 24.
[0027]
Here, the protective cover 1 attached to the airtight terminal 10 has a dimensional relationship as described above, between the small diameter hole 18 and the terminal pin 7, between the bulging portion 16 and the cylindrical portion 5, and between the folded portion 12 and the metal substrate 3. And a gap 20 is formed between the glass 6 and the surface. In the hermetic terminal 10 of the hermetic electric compressor configured as described above, the protective cover 1 not only completely covers the surface of the glass 6 but also a gap 20 between the protective cover 1 and the glass 6 surface. Is formed, the protective cover 1 can be kept away from the surface of the glass 6 having the strongest lines of electric force to some extent, and the amount of metal powder adsorbed to the protective cover 1 in the vicinity of the tubular portion 5 is greatly increased. Therefore, the spark generated between the terminal pin 7 and the metal substrate 3 can be prevented.
[0028]
Moreover, the electrical safety is improved by installing the airtight terminal 10 in the gas-phase refrigerant 24 in the sealed container 2. In the case of a low-pressure shell-type hermetic electric compressor in which the inside of the hermetic container is an intake pressure atmosphere, the density of the gas-phase refrigerant in which the hermetic terminal is installed is further reduced, and the safety is further improved.
[0029]
The material specification of the protective cover 1 selected in this configuration was selected by performing the following test. Put refrigerant, refrigerator oil, and test material in a glass sealed tube or metal container, maintain at a constant temperature of 130-140 ° C, 168-336h, and use refrigerant and test as indicators of deterioration of appearance and strength of the test material. The suitability of the material was evaluated.
[0030]
[Table 1]

[0031]
The test materials and test results are shown in (Table 1). In Table 1, the refrigerant is ammonia (Table Symbols: NH ₃₎ 100% pure refrigerant, ammonia (Table Symbols: NH ₃₎ 10 wt% and propane (Table Symbols: C ₃ H ₈₎ 90 wt% The refrigerating machine oil used was a 40 ° C. viscosity 46 mm ² / s alkylbenzene synthetic oil (symbol in the table: HAB46). Plastic materials include polyphenylene sulfide (symbol in the table: PPS), polysulfone (symbol in the table: PSF), polyethersulphone (symbol in the table: PES), polyether ether ketone (symbol in the table: PEEK), polyetherimide ( Table symbol: PEI), polyamideimide (table symbol: PAI), polyethylene terephthalate (table symbol: PET), polyethylene naphthalate (table symbol: PEN) were used. In addition, the deterioration level was relatively evaluated from visual discoloration of plastic specimens, comparison of turbidity of refrigerating machine oil, and change in strength, and expressed by symbols of 良好, ○, Δ, ×, XX in order of goodness.
[0032]
From the test results shown in Table 1, plastic materials having an ester bond in the molecular structure such as polyethylene terephthalate and polyethylene naphthalate have no ammonia resistance, are turbid, and have a great decrease in strength. As a result, it can be seen that polyphenylene sulfide, polysulfone, polyethersulfone, polyetheretherketone, polyetherimide, and polyamideimide are excellent in ammonia resistance and suitable as a protective cover material. As these materials, those materials alone or in combination are suitable.
[0033]
Further, from the test results shown in (Table 1), by reducing the ammonia concentration in the refrigerant, the deterioration of each plastic material was reduced, and the durability was improved.
[0034]
On the other hand, about the influence with respect to the moisture content in a refrigerant | coolant, and a metal material, it confirmed by performing the following tests. Put refrigerant, refrigerating machine oil, test material, and moisture in a glass sealed tube, maintain at a constant temperature of 130-175 ° C, 168h, and match the refrigerant and metal material using the appearance of the test material and the amount of metal in oil as indicators. Sex was evaluated.
[0035]
[Table 2]

[0036]
Table 2 shows test results and evaluation results of suitability. From Table 2, it was found that the deterioration was severe particularly when the water content was 500 ppm by weight or more, and was suppressed when the water content was 100 ppm by weight or less.
[0037]
Further, the terminal pin 7 is made of an alloy of iron, nickel, chromium, copper, copper alloy, or coated with plating or the like. In particular, the specific resistance of copper and copper alloys is small. The specific resistance of an alloy of 18% by weight of chromium, 8% by weight of nickel, and 74% by weight of iron is 72 μΩcm, for example, 1.72 μΩcm for copper and brass (copper 70% by weight and 30% by weight of zinc) is 5 to 7 μΩcm. By setting the water content in the refrigerant to 100 ppm by weight, copper or copper alloy having excellent conductivity can be used even in the refrigerant containing ammonia, and electrical loss during energization can be suppressed.
[0038]
Moreover, the schematic diagram of the refrigerating cycle using the said airtight type electric compressor is shown in FIG. In FIG. 4, 21 is the hermetic electric compressor, 26 is a condenser, 27 is a decompressor made of a capillary tube, and 28 is an evaporator. If a refrigeration system is used, even if a refrigerant containing ammonia is used, the protective cover will not melt or drop off, so that metal powder will not adhere to the glass, preventing sparking between the terminal pin and the metal outer ring, Prevents damage to terminals and improves safety.
[0039]
As a result of continuously operating the refrigeration apparatus of the present embodiment having the above-described configuration for about one month under an overload condition of a refrigeration oil temperature of 90 ° C., a high pressure side pressure of 2.72 MPa, and a low pressure side pressure of 0.35 MPa of a hermetic electric compressor, It was confirmed that the constituent materials were not sufficiently deteriorated and had sufficient durability.
[0040]
In this example, polyphenylene sulfide was used as the protective cover material. From the results shown in Table 1, polyphenylene sulfide, polysulfone, polyethersulfone, polyetheretherketone, polyetherimide, and polyamideimide were used alone or in combination. It can be expected that the same result can be obtained even if one is used.
[0041]
Moreover, although copper was used for the material of a terminal pin, from the result of (Table 2), even if it is excellent in electroconductivity containing copper, such as brass, it has ammonia resistance, and it can be anticipated that the same result will be obtained.
[0042]
【The invention's effect】
As described above, according to the present invention, even when a refrigerant containing ammonia is used, the protective cover of the hermetic terminal does not melt or fall off, so that the metal powder does not adhere to the glass, and the spark is generated between the terminal pin and the metal outer ring. Thus, it is possible to provide a hermetic type electric compressor including an airtight terminal which has an effect of being excellent in durability and material compatibility with ammonia while preventing leakage and breakage of the terminal.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a hermetic terminal of a hermetic electric compressor according to an embodiment of the present invention. FIG. 2 is a diagram showing a state where a protective cover of the hermetic electric compressor according to an embodiment of the present invention is attached to the hermetic terminal. FIG. 3 is a longitudinal sectional view of a hermetic electric compressor in an embodiment of the present invention. FIG. 4 is a schematic diagram of a refrigeration apparatus in an embodiment of the present invention. FIG. 6 is a sectional view of a hermetic terminal of a hermetic electric compressor that compresses a conventional chlorofluorocarbon refrigerant. FIG. 7 is a hermetic electric compressor that compresses a chlorofluorocarbon refrigerant. Sectional view of the hermetic terminal showing where the protective cover is attached to the hermetic terminal.
DESCRIPTION OF SYMBOLS 1 Protective cover 2 Sealed container 6 Glass 7 Terminal pin 10 Airtight terminal 21 Sealed electric compressor 24 Gaseous refrigerant 25 Refrigerating machine oil 26 Condenser 27 Depressurizer 28 Evaporator

Claims

A refrigerant whose main component is an electric element, ammonia and hydrocarbons in an airtight container , the ammonia composition ratio is 1 to 20% by weight, and the moisture content of the refrigerant during operation is 100 ppm by weight or less is compressed. In a hermetic electric compressor having a compression element, a metal outer ring having a through hole and a cylindrical portion surrounding the through hole is provided, and the surface is not provided with a coating on the through hole of the metal outer ring through glass. A terminal pin formed of copper or an alloy containing copper is hermetically insulated and sealed, inside the sealed container of the metal outer ring, an outer peripheral surface of the terminal pin, an outer peripheral surface of the cylindrical portion, and At least one member selected from the group consisting of polyphenylene sulfide, polysulfone, polyether sulfone, polyether ether ketone, polyether imide, and polyamide imide that is in close contact with the inner peripheral surface of the metal outer ring. Hermetic electric compressor protection cover formed is mounted, characterized by using a hermetic terminal affixed to the vessel through said sealed container used.

2. The hermetic electric compressor according to claim 1, wherein the hermetic terminal is installed in a gas-phase refrigerant atmosphere in the hermetic container.

3. The hermetic electric compressor according to claim 2, wherein the hermetic container is a low-pressure space serving as a suction pressure atmosphere into which refrigerant is fed.

The refrigerating apparatus which forms the refrigerating cycle which compresses, condenses, expands, and evaporates a refrigerant | coolant uses the hermetic type electric compressor of any one of Claims 1-3 . The refrigerating apparatus characterized by the above-mentioned.