JP4258132B2 - Rotary multistage compressor - Google Patents

Rotary multistage compressor Download PDF

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JP4258132B2
JP4258132B2 JP2001109623A JP2001109623A JP4258132B2 JP 4258132 B2 JP4258132 B2 JP 4258132B2 JP 2001109623 A JP2001109623 A JP 2001109623A JP 2001109623 A JP2001109623 A JP 2001109623A JP 4258132 B2 JP4258132 B2 JP 4258132B2
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stage
compression
oil
chamber
piston
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JP2002303284A (en
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勝晴 藤尾
澤井  清
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パナソニック株式会社
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04CROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C23/00Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids
    • F04C23/001Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids of similar working principle
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04CROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C18/00Rotary-piston pumps specially adapted for elastic fluids
    • F04C18/30Rotary-piston pumps specially adapted for elastic fluids having the characteristics covered by two or more of groups F04C18/02, F04C18/08, F04C18/22, F04C18/24, F04C18/48, or having the characteristics covered by one of these groups together with some other type of movement between co-operating members
    • F04C18/34Rotary-piston pumps specially adapted for elastic fluids having the characteristics covered by two or more of groups F04C18/02, F04C18/08, F04C18/22, F04C18/24, F04C18/48, or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in group F04C18/08 or F04C18/22 and relative reciprocation between the co-operating members
    • F04C18/356Rotary-piston pumps specially adapted for elastic fluids having the characteristics covered by two or more of groups F04C18/02, F04C18/08, F04C18/22, F04C18/24, F04C18/48, or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in group F04C18/08 or F04C18/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the outer member
    • F04C18/3562Rotary-piston pumps specially adapted for elastic fluids having the characteristics covered by two or more of groups F04C18/02, F04C18/08, F04C18/22, F04C18/24, F04C18/48, or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in group F04C18/08 or F04C18/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the outer member the inner and outer member being in contact along one line or continuous surfaces substantially parallel to the axis of rotation
    • F04C18/3564Rotary-piston pumps specially adapted for elastic fluids having the characteristics covered by two or more of groups F04C18/02, F04C18/08, F04C18/22, F04C18/24, F04C18/48, or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in group F04C18/08 or F04C18/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the outer member the inner and outer member being in contact along one line or continuous surfaces substantially parallel to the axis of rotation the surfaces of the inner and outer member, forming the working space, being surfaces of revolution
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04CROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C23/00Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids
    • F04C23/008Hermetic pumps

Description

【0001】
【発明の属する技術分野】
本発明はロータリ式多段圧縮機の給油手段に関するものである。
【0002】
【従来の技術】
昨今の地球環境保護問題に端を発して、従来から継続使用されているフロン冷媒に替わり自然冷媒、特に、二酸化炭素(CO2)冷媒を用いたヒートポンプシステムの研究開発が各分野で盛んに行われている。
【0003】
しかしながら、従来のフロン冷媒を用いた冷凍サイクルでは、高圧側が3MPa以下であるのに対して、二酸化炭素(CO2)冷媒を用いた冷凍サイクルでは、低圧側が2.5〜5MPa,高圧側が12〜15MPaにも達して高低圧力差が極めて大きく、圧縮機シリンダ内での圧縮途中気体漏れ損失の過大が懸念されている。
【0004】
このような理由から、二酸化炭素(CO2)冷媒を用いた圧縮機として、従来からの多段圧縮機の改良検討が進められている。特に、家庭用ヒートポンプシステムに搭載される圧縮機としては、生産性と耐久性および小型化の観点からロータリ式2段圧縮機が注目を浴びている。二酸化炭素(CO2)冷媒を用いた圧縮機は高圧側圧力が高いことから、高圧容器としての安全性と摺動部への給油性および圧縮効率を鑑みて、電動機を収納する密閉容器内を、吸入圧力と吐出圧力との中間圧力にする構成が適していることが知られている。
【0005】
このような電動機を収納する密閉容器内を中間圧力にする構成は、例えば、特開昭50−72205号公報で代表される。更には特開平2−294586号公報、特開平2−294587号公報、特開平7−318179号公報などでも提案されている。図10は特開平2−294587号公報で示されたフロン冷媒を使用する縦置形のローリングピストン型ロータリ式2段圧縮機の縦断面図、図11は同圧縮機の横断面図である。また、図12は特開平7−318179号公報で示されたフロン冷媒を使用する横置形のローリングピストン型ロータリ式2段圧縮機の部分断面図である。
【0006】
図10、図11において1001は密閉容器、1002は密閉容器1001内に設けられた電動機部、1003は電動機部1002の下に位置する1段目シリンダー(低段側シリンダブロック)、1004は1段目シリンダー(低段側シリンダブロック)1003の下方に位置する2段目シリンダー(高段側シリンダブロック)、1005は密閉容器1001に固定され1段目シリンダー(低段側シリンダブロック)1003と2段目シリンダー(高段側シリンダブロック)1004に挟まれた中板である。1006は2段目シリンダー(高段側シリンダブロック)1004の下に位置する下軸受端板(副軸受)、1007は電動機部1002と圧縮機部とを連結しているクランク軸(駆動軸)、1008は1段目シリンダー(低段側シリンダブロック)1003内で動く1段目ピストン(低段ピストン)、1009は2段目シリンダー(高段側シリンダブロック)1004内で動く2段目ピストン(高段ピストン)、1010は平板(高段吐出カバー)である。1011は1段目吸入管(低段吸入管)、1012は2段目吐出冷媒を直接、密閉容器1の外に出す2段目吐出管である。1013は2段目ベーン(高段ベーン)、1014は2段目ベーン(高段ベーン)1013を押さえているベーンバネ、1015は、2段目ベーン(高段ベーン)1013、中板1005、下軸受端板(副軸受)1006および2段目のシリンダーベーン溝により密閉容器1001内の冷媒と密閉隔離されたベーン背面室(高段背面室)1016は下軸受端板(副軸受)1006、平板(高段吐出カバー)1010に囲まれた2段目吐出弁室(高段吐出室)、1017はベーン背面室(高段背面室)1015と2段目吐出弁室(高段吐出室)1016を連通している導入路である。
【0007】
このような構成において、2段目吐出弁室(高段吐出室)1016の吐出冷媒ガスの一部は、導入路1017を介して2段目吐出弁室(高段吐出室)1016の上部に配置されたベーン背面室(高段背面室)1015に導かれて、ベーンバネと共に2段目ベーン(高段ベーン)1013の先端を2段目ピストン(高段ピストン)1009に適正な力で押付け、シリンダ内空間を吸入側と圧縮側とに仕切る一方、2段目吐出弁室(高段吐出室)1016の吐出冷媒ガスの大部分は、2段目吐出管1012を介して密閉容器1001の外部に排出される構成である。
【0008】
また、横置形のローリングピストン型ロータリ式2段圧縮機を示す図12において、密閉ケース(密閉容器)2020内に配置されたモータ部2021の回転軸(駆動軸)およびそのクランク部2025a,2025bを水平方向に配置している。中間ベアリング(中板)2028の下半分には、油吸込孔2052を半径方向に穿設して、回転軸(駆動軸)2025回りの油溜め孔2028aに連通させる一方、この油吸込孔2052の下端部2052aを潤滑油(油溜)2044中で開口させている。
【0009】
このような構成において、右側の1段目圧縮部の上部シリンダ2029から圧縮冷媒が吐出される密閉ケース(密閉容器)2020内と、中間ベアリング(中板)2028の油溜め孔2028a内との圧力差により、潤滑油2044が油吸込孔2052から油溜め孔2028aへ吸い上げられ、第1段目のピストンローラ2031の両側面隙間[ピストンローラ(ピストン)2031とメインベアリング(主軸受)2026との間の隙間、および、ピストンローラ(ピストン)2031と中間ベアリング(中板)2028との間の隙間]を介して1段目の上部シリンダ2029内の圧縮途中の圧縮室や吸入側に差圧給油される。その後、1段目圧縮部から密閉ケース(密閉容器)2020内に吐出された冷媒ガスに混入する潤滑油は、その一部が分離されて潤滑油2044に収集される一方、冷媒ガスから分離されない残りの潤滑油は、2段目の下部シリンダ2030内を経て密閉ケース(密閉容器)2020外に排出される。そして潤滑油2044は、その経路途中で摺動面を潤滑する構成である。
【0010】
【発明が解決しょうとする課題】
しかしながら図10、図11に示すこのような構成では、以下に述べる課題があった。すなわち、第1の課題は、ベーン背面室(高段背面室)1015の吐出冷媒ガスが2段目ベーン(高段ベーン)1013の摺動部微小隙間を通して圧縮室に漏洩流入するので、圧縮効率が著しく低下すると共に、2段目ベーン(高段ベーン)1013の摺動部微小隙間への給油不足から2段目ベーン(高段ベーン)1013の耐久性確保が困難であるという課題である。
【0011】
また第2の課題は、2段目吐出弁室(高段吐出室)1016に排出された冷媒ガスが2段目吐出管1012を介して密閉容器1001の外部の冷凍サイクルに排出されるので、2段目吐出弁室(高段吐出室)1016に排出された冷媒ガス中の潤滑油が密閉容器1001に直接戻されることがなく、密閉容器1001内の潤滑油不足を招くと共に、冷凍サイクルへの潤滑油排出による熱交換器の効率低下も同時に引き起こすという課題である。
【0012】
また第3の課題は、2段目シリンダ1013内で圧縮途中の冷媒ガスが2段目ピストン1009の端面隙間(2段目ピストン1009と中板1005との間の隙間)を介して2段目ピストン1009の内側(1段目吐出圧力相当)に漏洩することによる、いわゆるガス吹きぬけによって、クランク軸(駆動軸)1007を支持する軸受摺動部や、クランク軸(駆動軸)1007と第1ピストン1008および第2ピストン1009との摺動部の良好な潤滑油膜形成が阻害され、圧縮機耐久性の低下を招くという課題である。
【0013】
また図12のような横置形における給油通路の構成においても、上記第3の課題と同様な課題があった。すなわち、潤滑油2044に通じる油溜め孔2028aと密閉ケース(密閉容器)2020内とが同圧力のために、潤滑油2044から油溜め孔2028aへの充分な差圧給油量確保が望めない。更には、回転軸(駆動軸)2025を支持するメインベアリング(主軸受)2026とサブベアリング(副軸受)2027の軸受摺動面への積極的な給油ができず、回転軸(駆動軸)2025の損傷を招くという密閉ケース(密閉容器)2020内を中間圧力(圧縮機の低圧側圧力と高圧側圧力との中間圧力)にした横置形構成における差圧給油量確保の課題があった。
【0014】
本発明はこのような従来の課題を解決するものであり、高段側ベーン背面室や軸受摺動部への充分な差圧給油量確保を図ることを目的とするものである。
【0015】
【課題を解決するための手段】
上記課題を解決するために本発明は、高段吐出側の油溜の潤滑油を高段側ベーン背面室および駆動軸の摺動部を経由して密閉容器内に戻す差圧給油通路の形成を図るものである。上記高段側ベーン背面室および駆動軸の摺動部を通過する差圧給油通路の形成と密閉容器内への潤滑油回収・確保によって、高段側ベーン背面室からシリンダ内圧縮空間への吐出冷媒ガスの流入を防止し、圧縮効率の向上と駆動軸およびベーン耐久性の向上、および冷凍サイクルの効率向上ができる。
【0016】
【発明の実施の形態】
請求項1に記載の発明は、密閉容器内に複数の圧縮要素を順次直列接続した多段圧縮機構と前記多段圧縮機構の駆動軸に連結する電動機とを収納し、圧縮要素の各シリンダ内を出没(前進・後退)しつつ吸入室と圧縮室とに区画する各ベーンの内の高段(最終段)圧縮要素の高段(最終段)ベーンの高段(最終段)背面室が高段(最終段)圧縮要素の吐出側に連通する一方、低段(初段)圧縮要素の吐出側が密閉容器内に連通した構成において、高段(最終段)圧縮要素の吐出側で気体から分離した潤滑油を、高段(最終段)背面室を経由して前記密閉容器内に戻す絞り通路を備えた油戻し通路を備えたものである。そしてこの構成によれば、高段(最終段)吐出側で吐出気体から分離した潤滑油が高段(最終段)背面室に供給され、その潤滑油が高段(最終段)ベーンの摺動部隙間を潤滑・油膜密封し、高段側吐出気体が高段(最終段)ベーンの摺動部隙間を通じてシリンダ内に流入するのを防ぐと共に、密閉容器内に潤滑油を回収することによって冷凍サイクルへの潤滑油吐出量を少なくできる。
【0017】
請求項2に記載の発明は、高段(最終段)背面室が高段(最終段)圧縮要素の高段(最終段)吐出室の油溜を兼ねるべく構成されたものである。そしてこの構成によれば、高段(最終段)吐出室で吐出冷媒から分離した潤滑油が高段(最終段)背面室を経由して密閉容器内に回収され、圧縮機外部での簡易油分離手段の配設が可能となる。
【0018】
請求項3に記載の発明は、油戻し通路が駆動軸を支持する軸受摺動部を経由すべく構成されたものである。そしてこの構成によれば、高段(最終段)背面室の潤滑油が駆動軸の軸受摺動部を潤滑した後、最終的に密閉容器内に回収されて、圧縮機構の外周囲を取り巻く。その結果、潤滑油膜が圧縮機構部を構成する部品間の接合面を密封し、密閉容器内の気体が低段(初段)圧縮要素のシリンダ内に流入するのを防止できる。
【0019】
請求項4に記載の発明は、圧縮機構を高段圧縮要素と低段圧縮要素から成る2段圧縮機構とし、その油戻し通路は、高段圧縮要素と低段圧縮要素との間に配置した中板と、各圧縮要素のピストンの内側とを順次経由すべく設けられたものである。そしてこの構成によれば、高段(最終段)背面室の潤滑油が、高段(最終段)ベーン、各圧縮要素のピストン内側、駆動軸を支持する軸受摺動部に順次供給され、効率の良い給油通路を形成できる。
【0020】
請求項5に記載の発明は、油戻し通路は、最終段圧縮要素と初段圧縮要素との間に配置した中板を経由すべく構成し、絞り通路を中板に設けたものである。そしてこの構成によれば、高段(最終段)背面室から駆動軸までの適正距離を備えた給油通路を経て安定した絞り効果による継続的な潤滑油供給ができる。
【0021】
請求項6に記載の発明は、駆動軸を支持する軸受は少なくとも電動機に近い側に配置された主軸受を含み、油戻し通路を介して密閉容器内に流入する潤滑油の内の半分以上が主軸受の摺動部を通過すべく主軸受の軸受隙間を設定したものである。そしてこの構成によれば、電動機の磁気吸引力が駆動軸に作用して主軸受に過大負荷が作用する場合でも、密閉容器内に戻される潤滑油の内の半分以上の潤滑油供給によって、主軸受の摺動面に十分な油膜形成ができる。
【0022】
請求項7に記載の発明は、各ピストンの内側空間が最終段吐出室の圧力相当になるように軸受隙間を設定したものである。そしてこの構成によれば、各圧縮要素のシリンダ内の圧縮途中冷媒ガスが、各ピストンの内側空間に漏洩するのが阻止され、駆動軸を支持する主軸受の軸受摺動面へのガス噛み込みを防止できる。
【0023】
請求項8に記載の発明は、駆動軸を支持する軸受は少なくとも電動機に近い側に配置された主軸受と電動機に遠い側に配置された副軸受とから成り、油戻し通路を介して密閉容器内に流入する潤滑油の内の大部分が主軸受と副軸受の摺動部を通過すべく油戻し通路を構成したものである。そしてこの構成によれば、高段(最終段)圧縮要素の吐出側で回収され且つ密閉容器内に戻される途中の潤滑油が軸受摺動面への給油に有効活用され、軸受耐久性を向上させることができる。
【0024】
請求項9に記載の発明は、油戻し通路が、中板と摺接するピストンの側面を経由すべく構成されたものである。そしてこの構成によれば、高段(最終段)背面室からの潤滑油が中板とピストンとの摺接側面を油膜密封し、シリンダ内の圧縮途中冷媒ガスがピストン内側に漏洩するのを防止できる。
【0025】
請求項10に記載の発明は、油戻し通路は、中板に設けられたピストン摺接開口部が、最終段圧縮要素のシリンダ内と連通せず且つ最終段ピストンの側面と対向する位置に設けられたものである。そしてこの構成によれば、潤滑油が中板と最終段ピストンの摺接側面を潤滑すると共に、その摺接側面を通過する潤滑油を減圧する絞り通路を簡易手段で形成することができる。
【0026】
請求項11に記載の発明は、中板に設けられたピストン摺接開口部が、最終段ピストンによって間欠的に開閉されるべく位置に配置されたものである。そしてこの構成によれば、ピストンの旋回運動速度が増加するに伴い、中板内の油通路からピストン内側に向かって通過する潤滑油の通路抵抗が増すべく、給油通路抵抗調整が行なわれ、高段(最終段)背面室から密閉容器内へ流出させる潤滑油量調整ができる。
【0027】
請求項12に記載の発明は、最終段ピストンの両側面に開通する貫通油穴を設け、貫通油穴は中板に設けた摺接開口部と間欠的に連通すべく配置されたものである。そしてこの構成によれば、中板内を経由した潤滑油が、中板と摺接しないピストン側面にも供給され、そのピストン側面の油膜形成によって、シリンダ内の圧縮途中冷媒ガスがピストン内側に漏洩するのを防止できる。
【0028】
以下本発明の実施例について図面を参照して説明する。
【0029】
(実施例1)
図1は二酸化炭素冷媒を使用したローリングピストン型ロータリ式2段圧縮機の縦断面を表し、図2は図1における2段圧縮機構部の部分縦断面を表し、図3は図1におけるA−A線に沿った横断面を表す。
【0030】
密閉容器1の内部に、電動機2とその下部に2段圧縮機構3が配置されている。
2段圧縮機構3は、高段(最終段)圧縮要素4と、その下部に配置された低段(初段)圧縮要素5と、高段(最終段)圧縮要素4および低段(初段)圧縮要素5の間に配置された中板6と、高段(最終段)圧縮要素4および低段(初段)圧縮要素5を駆動すべく電動機2の回転子2aに連結された駆動軸7と、駆動軸7を支持すべく高段(最終段)圧縮要素4の高段(最終段)側シリンダブロック8に固定された主軸受9および低段(初段)圧縮要素5の低段(初段)側シリンダブロック10に固定された副軸受11とから成る。
【0031】
高段(最終段)側シリンダブロック8に固定され且つその外周部が密閉容器1に溶接固定された高段(最終段)吐出カバー12は、主軸受9のシリンダブロック取付フランジ部9aを囲み且つ軸受本体9bの外周部を囲む様態で配置されて高段(最終段)吐出室13を形成している。 高段(最終段)吐出室13の底部は油溜14を形成し、高段(最終段)ベーン15の反圧縮室側に形成された高段(最終段)背面室16に常時連通している。
【0032】
高段(最終段))背面室16は、圧縮機外部の吐出配管系に配置されて圧縮機から放熱器の方向へのみの冷媒流れを許容する逆止弁手段98の下流側に接続された油分離器99の底部に接続され且つ密閉容器1の側壁を貫通して高段側シリンダブロック8に挿入された油戻し管152に連通している。高段側シリンダブロック8には、バネケース64が圧入されている。バネケース64には、高段(最終段)圧縮要素4を構成する高段(最終段)ピストン65に向かって高段(最終段)ベーン15を付勢する高段(最終段)ベーンバネ66と、油戻し管152の開口端部通路を開閉する鋼球製の弁体67を収納する。高段(最終段)ベーンバネ66は弁体67を油戻し管152の側に付勢して、油戻し管152の開口端部通路を閉塞する。また、高段(最終段)ベーンバネ66は、それ自身の温度上昇に伴ってバネ定数が増加する一方、それ自身の温度下降に伴ってバネ定数が減少する形状記憶特性を有している。
【0033】
高段(最終段)吐出室13は、主軸受9のシリンダブロック取付フランジ部9aに立ち上げ固定された排出管19を経由し且つ密閉容器1の側壁を貫通して形成された吐出冷媒ガス排出通路20によって圧縮機外部吐出配管系21に通じている。 主軸受9に設けられた高段(最終段)圧縮要素4の圧縮室に開口する吐出口22は、シリンダブロック取付フランジ部9aに凹設された吐出弁室23に取付られた吐出弁装置24によって開閉される。吐出弁室23の吐出口側端は、圧縮室から吐出冷媒ガスと共に吐出口22から排出した潤滑油が高段(最終段)背面室16に流入容易なように、高段(最終段)背面室16に向かって配置されている。
【0034】
副軸受11と共に低段(初段)側シリンダブロック10に固定された低段(初段)吐出カバー26は、副軸受11と共に低段(初段)吐出室27を形成する。低段(初段)吐出室27は、副軸受11と低段(初段)シリンダブロック10と中板6と高段(最終段)シリンダブロック8と高段(最終段)吐出カバー12を順次連通して形成された中間ガス通路28を経由して電動機2が収納されている電動機室29に通じている。
【0035】
中間ガス通路28の終端は、高段(最終段)吐出カバー12に装着された放出管39によって電動機2のコイルエンド2cに接近している。放出管39とは反対側位置のコイルエンド2cの近傍に開口する中間吸込管39aが高段圧縮要素4の吸入側に連通している。密閉容器1の底部の油溜32と電動機室29との間は、高段(最終段)吐出カバー12に設けられた油落とし穴33(図3参照)を介して連通している。
【0036】
低段(初段)圧縮要素5の低段(初段)背面室33は、ベーンバネ装着穴34を介して油溜32に連通している。高段(最終段)背面室16は、中板6に設けられて一端がネジ装着されたネジ溝隙間で形成された絞り通路68bを介して密閉容器1内に通じる一方、他端が開口された細穴68を通じて最終段(高段)ピストン65の内側空間に通じている。
【0037】
以上のように構成された二酸化炭素冷媒ガスを使用したローリングピストン型ロータリ式2段圧縮機について、その動作を説明する。
【0038】
密閉容器1の側壁を貫通する低段(初段)吸入管36を通じて低段(初段)圧縮要素5のシリンダ内に取り込まれた冷媒ガスは副軸受11に設けられた極細孔35を通じて油溜32から減圧導入された潤滑油を混入状態で圧縮された後、低段(初段)吐出室27に排出された後、中間ガス通路28と放出管39を経由して電動機室29に排出される。なお、吸入冷媒ガスと共に低段(初段)圧縮要素5のシリンダ内に取り込まれた潤滑油は、圧縮室の微小隙間の油膜密封に供され、圧縮途中冷媒ガス漏れ防止に寄与する。
【0039】
電動機室29に流入した冷媒ガスは、コイルエンド2cに衝突する。その際に、冷媒ガスに混入する潤滑油が分離される。その後、冷媒ガスは中間吸込管39aを経て高段(最終段)圧縮要素4のシリンダ内に取り込まれる。この冷媒ガスのコイルエンド2cに沿った流れによって冷媒ガスに混入する潤滑油が分離されると共に、電動機2が冷却される。
【0040】
電動機室29で冷媒ガスから分離されなかった潤滑油、あるいは、油溜32の油面が中間吸入管39aの上部開口端近傍にまで貯溜した潤滑油の一部は、冷媒ガスと共に高段(最終段)圧縮要素4のシリンダ内に取り込まれ、冷媒ガスと圧縮の後、吐出口22から高段(最終段)吐出室13に排出される。
【0041】
吐出口22から排出された冷媒ガスの一部は、吐出弁室23に沿って高段(最終段)背面室16の方向に流れ、高段(最終段)吐出カバー12の内壁面に衝突し、冷媒ガスに混入する潤滑油の一部が分離され、高段(最終段)背面室16に流入する。吐出口22から排出された残りの冷媒ガスは、高段(最終段)吐出カバー12の内壁面全域と衝突し、冷媒ガスから分離した潤滑油が主軸受9のシリンダブロック取り付けフランジ部9aの外周を囲むように高段(最終段)側シリンダブロックに設けられら環状油溝14a、および、その下部に配置された高段(最終段)背面室16と共に構成される油溜14に収集する。
【0042】
高段(最終段)背面室16の潤滑油は、高段(最終段)ベーン15の往復運動によってポンプ作用を受けて油溜14の油面側と底面側とに出入りする。一方、高段(最終段)背面室16の潤滑油の一部は、中板6に設けられた絞り通路68bを介して密閉容器1内に戻されると共に、高段(最終段)背面室16の潤滑油の大部分は、油穴68を介して高段(最終段)ピストン65と低段(初段)ピストン70の内側空間に流入後、主軸受9の軸受摺動部9c,副軸受11の軸受摺動部11cの各々の微小軸受隙間を経由する間に減圧され、電動機室29に差圧給油される。
【0043】
なお、潤滑油が主軸受9と副軸受11の軸受隙間を通過して電動機室29に流入する際に、潤滑油が主軸受9の軸受隙間を副軸受11の軸受隙間より多く通過すべく、両軸受の軸受隙間の通路抵抗が設定されており、主軸受への十分な給油が行われる。その結果、駆動軸に連結された電動機の回転子のアンバランスに起因して主軸受9に作用する振動や過負荷に対して、良好な油膜形成と軸受摺動面の冷却ができる。
【0044】
また、高段(最終段)ピストン65と低段(初段)ピストン70の内側空間に供給された潤滑油は、高段(最終段)ピストン65と主軸受9および中板6との各々の摺動隙間(ピストン側面隙間)、低段(初段)ピストン70と副軸受11および中板6との各々の摺動隙間(ピストン側面隙間)を介して、高段(最終段)圧縮要素4と低段(初段)圧縮要素5の各々のシリンダ内にも取り込まれる。
【0045】
高段(最終段)背面室16から電動機室29および各圧縮要素(4,5)のシリンダ内に差圧給油される潤滑油は、その経路途中の摺動面潤滑に提供される。排出管19を通じて高段(最終段)吐出室13から圧縮機外部に排出された吐出冷媒ガスは、放熱器(図示なし)の上流側に配置された油分離器99を通して潤滑油が分離され、その底部の油溜99aに貯溜される。
【0046】
油溜32より高位置で配置された油分離器99の潤滑油は、圧縮機停止後の冷凍サイクルが均圧した状態[圧縮機内温度が低下し、弁体67に作用する高段(最終段)ベーンバネの付勢力が弱い状態]で、弁体67の閉塞機能が低下するにで、潤滑油自身の自重により油戻し管152を介して高段(最終段)背面室16に流入する。また、圧縮機と油分離器99の間に配置された逆止弁手段98の逆止作用によって、圧縮機停止直後における圧縮機内均圧圧力と油分離器99との間の差圧によっても、油分離器99の潤滑油が高段(最終段)背面室16に戻される。圧縮機運転中の油分離器99の潤滑油は、油戻し管152の開口端を弁体67が閉塞(高段(最終段)ベーンバネの微小バネ付勢力を受けている)しており、圧縮機内に戻ることはない。
【0047】
圧縮機停止中に油分離器99から高段(最終段)背面室16に帰還した潤滑油は、中板6に設けた油穴68、高段(最終段)ピストン65と低段(初段)ピストン70の内側空間を経由して、最終的に、油溜32に戻る。
【0048】
以上のように上記実施例によれば、密閉容器1内に低段(初段)圧縮要素5と高段(最終段)圧縮要素4を直列接続した2段圧縮機構3とその2段圧縮機構3の駆動軸7に連結する電動機2とを収納し、各圧縮要素4,5の各シリンダ内を出没(前進・後退)しつつ吸入室と圧縮室とに区画する各ベーンの内の高段(最終段)圧縮要素4の高段(最終段)ベーン15の高段(最終段)背面室16と高段(最終段)吐出室13とを連通する一方、低段(初段)圧縮要素5の吐出側が密閉容器1内に連通した構成において、高段(最終段)圧縮要素4の吐出側で気体から分離した潤滑油を、高段(最終段)背面室16を経由して密閉容器内1に戻す絞り通路(主軸受9と副軸受11の軸受隙間)を備えた油戻し通路68および絞り通路68bを備えたことにより、高段(最終段)吐出室13側で吐出気体から分離した潤滑油が高段(最終段)背面室16に供給され、その潤滑油が高段(最終段)ベーン15の摺動部隙間を潤滑・油膜密封し、高段側吐出気体が高段(最終段)ベーン15の摺動部隙間を通じてシリンダ内に流入するのを防ぎ、高段(最終段)圧縮要素4の圧縮効率を向上させることができる。また、圧縮機停止中は、油分離器99の油溜99aの潤滑油を油戻し管152を介して密閉容器1内に潤滑油を回収することによって冷凍サイクルへの潤滑油吐出量を少なくして、熱交換器の効率を向上することによる冷凍サイクルの効率も向上させることができる。
【0049】
また上記実施例によれば、高段(最終段)背面室16が高段(最終段)圧縮要素4の高段(最終段)吐出室13の油溜14を兼ねるべく構成されたことにより、高段(最終段)吐出室13で吐出冷媒から分離した潤滑油が高段(最終段)背面室14を経由して密閉容器1内に回収できるので、高段(最終段)吐出室13で冷媒ガスから分離されずに圧縮機外部に排出された潤滑油が簡易構成の油分離器99でも簡易に油分離され、圧縮機停止後の機内圧力バランス状態で密閉容器1内に回収することができ、圧縮機内油量確保による耐久性確保を図ることができる。
【0050】
また上記実施例によれば、油戻し通路68が駆動軸7を支持する主軸受9と副軸受11の軸受摺動部を経由すべく構成されたことにより、高段(最終段)背面室16の潤滑油が駆動軸7の軸受摺動部を潤滑した後、最終的に密閉容器1内に回収されて、圧縮機構の外周囲を取り巻くので、潤滑油膜が多段圧縮機構部3を構成する部品間の接合面を密封し、密閉容器1内の気体が低段(初段)圧縮要素5のシリンダ内に流入するのを防止して圧縮効率を向上させることができる。
【0051】
また上記実施例によれば、圧縮機構を高段圧縮要素5と低段圧縮要素4から成る2段圧縮機構3とし、高段吐出室13で分離した潤滑油を高段背面室16を経由して密閉容器1内に戻す油戻し通路68が、高段圧縮要素5と低段圧縮要素4との間に配置した中板6と、各圧縮要素4,5のピストン65,70の内側とを順次経由すべく設けられたことにより、高段背面室16の潤滑油が、高段ベーン15、各圧縮要素のピストン65,70内側、駆動軸7を支持する主軸受9と副軸受11の軸受摺動部に順次供給させる効率の良い給油通路を形成できるので、冷媒ガス中に混入させる潤滑油量を少なくしてシリンダ内での油圧縮を回避して圧縮入力を低減することができる。
【0052】
また上記実施例によれば、駆動軸7を支持する軸受は少なくとも電動機2に近い側に配置された主軸受9を含み、油戻し通路68を介して密閉容器1内に流入する潤滑油の内の半分以上が主軸受9の摺動部を通過すべく主軸受9の軸受隙間を設定したことにより、電動機2の磁気吸引力が駆動軸7に作用して主軸受9に過大負荷が作用する場合でも、密閉容器1内に戻される潤滑油の内の半分以上の潤滑油を供給することによって、主軸受9の摺動面に十分な油膜を形成して、軸受耐久性を向上させることができる。
【0053】
また上記実施例によれば、各ピストン65,70の内側空間が高段(最終段)吐出室13の圧力相当になるように軸受隙間を設定したことにより、各圧縮要素4,5のシリンダ内の圧縮途中冷媒ガスが、各ピストン65,70の内側空間に漏洩するのが阻止され、駆動軸7を支持する主軸受9の軸受摺動面へのガス噛み込みを防止して、良好な軸受油膜形成によって軸受耐久性の向上と、軸受摩擦損失の低減による圧縮機入力の低減ができる。
【0054】
また上記実施例によれば、駆動軸7を支持する軸受は少なくとも電動機2に近い側に配置された主軸受9と電動機2に遠い側に配置された副軸受11とから成り、油戻し通路68を介して密閉容器内1に流入する潤滑油の内の大部分が主軸受9と副軸受11の摺動部を通過すべく油戻し通路68を構成したことにより、高段(最終段)圧縮要素4の吐出側で回収され且つ密閉容器1内に戻される途中の潤滑油が軸受摺動面への給油に有効活用され、軸受耐久性を向上させることができる。
【0055】
(実施例2)
図4は二酸化炭素冷媒を使用したローリングピストン型ロータリ式2段圧縮機において、圧縮機を横置形に構成した部分縦断面図を表し、図5は図4におけるB−B線に沿った横断面図を表す。
【0056】
密閉容器101の内部に、電動機102とその横部に2段圧縮機構103が配置されている。すなわち、2段圧縮機構103の低段(初段)圧縮要素105が電動機102の側に配置され、高段(最終段)圧縮要素104が反電動機の側に配置されている。低段(初段)圧縮要素105の低段(初段)側シリンダブロック110は密閉容器101に溶接固定され、その低段(初段)側シリンダブロック110に固定された駆動軸107を支持する主軸受109が電動機側に配置される一方、反電動機側には、中板106、高段(最終段)側シリンダブロック108、駆動軸107を支持する副軸受111、高段(最終段)吐出カバーが順次・配置されている。
【0057】
主軸受109に配置された低段(初段)圧縮要素105の吐出口173は電動機室129に直接開口している。高段(最終段)圧縮要素104のシリンダ内に取り込まれる吸入冷媒ガスは、高段(最終段)吐出カバー126に取り付けられ且つ電動機室129への開口端が駆動軸107の軸芯より高い位置に設けられた中間吸い込み管139aを介して導入されるべく構成されている。高段(最終段)吐出室113は、副軸受111と高段(最終段)側シリンダブロック108に設けられた吐出ガス排出通路120を介して圧縮機外部吐出配管系121に連通している。
【0058】
低段(初段)圧縮要素105の低段(初段)背面室133と高段(最終段)圧縮要素104の高段(最終段)背面室116は、駆動軸107の下部に配置されている。低段(初段)背面室133は油溜132に連通している。高段(最終段)背面室116は高段(最終段)吐出室113の底部に設けられた油溜114の底部に通じている。低段(初段)背面室133のベーンバネ装着穴134aの底部は、副軸受111に設けられた油穴168を介して、駆動軸107の端部油溜空間171に通じている。
【0059】
駆動軸107の端部油溜空間171は、駆動軸107に設けられた軸穴172,駆動軸107を支持する主軸受109の微小軸受隙間を順次・経由して電動機室129に通じている。その他の構成は、実施例1と同様または類似の構成であり、説明を省略する。
【0060】
以上のように構成された二酸化炭素冷媒ガスを使用したローリングピストン型ロータリ式2段圧縮機について、図4、図5を参照しながらその動作を説明する。
【0061】
低段吸入管136から低段(初段)圧縮要素105に取り込まれた冷媒ガスは、圧縮の後、電動機室129に吐出され、潤滑油の大部分が冷媒ガスから分離される。その後、冷媒ガスは2段圧縮機構103の外周部を冷却しながら、更に、潤滑油が分離された後、中間吸入管139aを経由して高段(最終段)圧縮要素104に取り込み・圧縮の後、高段(最終段)吐出室113、吐出冷媒ガス排出通路120を順次経由して圧縮機外部に排出される。
【0062】
高段(最終段)吐出室113に排出された冷媒ガスが高段(最終段)吐出カバー112の内壁に衝突などして冷媒ガス中から分離した潤滑油は、高段(最終段)吐出カバー112の内壁を伝って下部の油溜132、高段(最終段)背面室116、ベーンバネ装着穴134へと順次・流下し収集される。
【0063】
高段(最終段)ベーン115が高段(最終段)ピストン165の側に前進・後退することによって、高段(最終段)背面室116とベーンバネ装着穴134の潤滑油がポンプ作用を受ける。このポンプ作用によって、高段(最終段)背面室116の潤滑油が高段(最終段)ベーン115の摺動面を経由してシリンダ内に適正給油される。また、同時に、このポンプ作用によって、ベーンバネ装着穴134の潤滑油が副軸受111に設けられた油穴168を経由して軸端油溜171に供給される。
【0064】
軸端油溜171の潤滑油は、軸穴172を経由して駆動軸107に係合する副軸受111、高段(最終段)ピストン165、低段(初段)ピストン170、主軸受109との摺動面を経由して電動機室129に差圧給油される。主軸受109の微小軸受隙間を通過する際に、高段(最終段)吐出圧力相当の潤滑油は減圧される。したがって、低段(初段)ピストン170の内側空間の潤滑油は、高段(最終段)吐出圧力相当をの圧力を維持している。
【0065】
上記実施例によれば、密閉容器101内に低段(初段)圧縮要素105と高段(最終段)圧縮要素104を直列接続した2段圧縮機構103とその2段圧縮機構103の駆動軸107に連結する電動機102とを収納し、各圧縮要素104,105の各シリンダ内を出没(前進・後退)しつつ吸入室と圧縮室とに区画する各ベーンの内の高段(最終段)圧縮要素104の高段(最終段)ベーン115の高段(最終段)背面室116と高段(最終段)吐出室113とを連通する一方、低段(初段)圧縮要素105の吐出側が密閉容器101内に連通した構成において、高段(最終段)圧縮要素104の吐出側で気体から分離した潤滑油を、高段(最終段)背面室116を経由して密閉容器内101に戻す絞り通路(主軸受109と副軸受111の軸受隙間)を備えた油戻し通路168を備えたことにより、高段(最終段)吐出室113側で吐出気体から分離した潤滑油が高段(最終段)背面室116に供給され、その潤滑油が高段(最終段)ベーン115の摺動部隙間を潤滑・油膜密封し、高段側吐出気体が高段(最終段)ベーン115の摺動部隙間を通じてシリンダ内に流入するのを防ぎ、高段(最終段)圧縮要素104の圧縮効率を向上させると共に、密閉容器101内に潤滑油を回収することによって冷凍サイクルへの潤滑油吐出量を少なくして、熱交換器の効率を向上することによる冷凍サイクルの効率も向上させることができる。
【0066】
(実施例3)
図6は二酸化炭素冷媒を使用したローリングピストン型ロータリ式2段圧縮機において、上記実施例2における差圧給油通路を、中板206に設けた油穴268を経由して構成した部分縦断面図を表し、図7は給油通路の部分拡大図を表し、図8はピストンの外観を表す。
【0067】
すなわち、高段(最終段)背圧室216は、ベーンバネ装着穴234a、中板206に設けた油穴268を介して高段(最終段)ピストン265および低段(初段)ピストン270の内側空間に通じ、更に、駆動軸207を支持する主軸受209と副軸受211の微小軸受隙間を経由して、電動機室229に通じている。高段(最終段)背圧室216の潤滑油は、上記通路を経て、以下に述べる絞り通路で順次・減圧されながら差圧給油される。
【0068】
高段(最終段)背圧室216の潤滑油は、油穴268の途中に配置された第1の絞り通路268a、油穴268の下流部に配置されて低段(初段)ピストン270と高段(最終段)ピストン265の中板摺接面に向けて開口して設けられた第2の絞り通路268c(図7参照)、低段(初段)ピストン270に設けられた軸方向油穴270a(図7、図8参照)と高段(最終段)ピストン265に設けられた軸方向油穴265a(図7、図8参照)を経て順次・減圧される。
【0069】
なお、第2の絞り通路268cと軸方向貫通油穴270aおよび軸方向貫通油穴265aとは、低段(初段)ピストン270と高段(最終段)ピストン265が旋回運動することによっって、間欠的に連通する。この間欠連通によって潤滑油が減圧作用を受ける。軸方向油穴270aおよび軸方向油穴265aを経由した潤滑油は、低段(初段)ピストン270と主軸受209との摺接面、高段(最終段)ピストン265と副軸受211との摺接面を潤滑して低段(初段)ピストン270、高段(最終段)ピストン265の内側空間に供給される。
【0070】
したがって、油穴268の潤滑油は低段(初段)ピストン270、高段(最終段)ピストン265、駆動軸207を経由する各摺動面を潤滑しながら電動機室229に差圧給油される。また、高段(最終段)背圧室216の潤滑油は、中板206に設けられた第3の絞り通路を経て電動機室229の底部の油溜232に戻される。その他の構成は、上記実施例と同様なので、説明を省略する。
【0071】
上記実施例によれば、高段(最終段)吐出室213の油溜214から密閉容器内の油溜232への油戻し通路は、高段(最終段)圧縮要素204と低段(初段)圧縮要素205との間に配置した中板206を経由すべく構成し、絞り通路206aを中板206に設けて適正な絞り通路長さを設定することにより、高段(最終段)背面室216から駆動軸207までの安定した絞り効果による継続的な潤滑油供給ができ、摺接面の耐久性向上を図ることができる。
【0072】
また上記実施例によれば、高段(最終段)吐出室213の油溜214から密閉容器内の油溜232への油戻し通路が、中板206と摺接する低段(初段)ピストン270、高段(最終段)ピストン265の側面を経由すべく構成されたことにより、高段(最終段)背面室216からの潤滑油が中板206と低段(初段)ピストン270、高段(最終段)ピストン265との摺接側面を油膜密封し、各シリンダ内の圧縮途中冷媒ガスが各ピストン内側に漏洩するのを防止して、圧縮効率を向上できる。
【0073】
また上記実施例によれば、高段(最終段)吐出室213の油溜214から密閉容器内の油溜232への油戻し通路は、中板206に設けられた各ピストン(265,270)の摺接開口部が、高段(最終段)圧縮要素204のシリンダ内と連通せず且つ低段(初段)ピストン270および高段(最終段)ピストン265の側面と対向する位置に設けられたことにより、潤滑油が中板206と低段(初段)ピストン270および高段(最終段)ピストン265の摺接側面を潤滑すると共に、その摺接側面を通過する潤滑油を減圧する絞り通路を簡易手段で形成してコスト低減を図ることができる。
【0074】
また上記実施例によれば、中板206に設けられた各ピストン(265,270)摺接開口部が、各ピストン(265,270)によって間欠的に開閉されるべく位置に配置されたことにより、各ピストン(265,270)の旋回運動速度が増加するに伴い、中板206内の油通路から各ピストン(265,270)内側に向かって通過する潤滑油の通路抵抗が増すべく、給油通路抵抗調整が行なわれ、高段(最終段)背面室216から密閉容器内へ流出させる潤滑油量調整を圧縮機運転速度に追従させて実現できる。
【0075】
また上記実施例によれば、低段(初段)ピストン270および高段(最終段)ピストン265の両側面に開通する軸方向貫通油穴270aおよび軸方向貫通油穴265aを設け、軸方向貫通油穴270aおよび軸方向貫通油穴265aは中板206に設けた摺接開口部と間欠的に連通すべく配置されたことにより、中板206内を経由した潤滑油が、中板206と摺接しない各ピストン(265,270)側面にも供給され、そのピストン側面の油膜形成によって、シリンダ内の圧縮途中冷媒ガスがピストン内側に漏洩するのを防止して圧縮効率の向上を図ることができる。
【0076】
(実施例4)
図9は二酸化炭素冷媒を使用したローリングピストン型ロータリ式2段圧縮機において、上記実施例1における2段圧縮機構と電動機を横置き構成にした部分縦断面図を表す。
【0077】
すなわち、中間吸入管339aは高段(最終段)圧縮要素304の吸入側に連通すべく配置されている。上記構成において、低段(初段)圧縮要素305で圧縮された冷媒ガスは電動機室329に排出された後、2段圧縮機構の外表面を冷却しながら、中間吸入管339aを経由して、高段(最終段)圧縮要素304のシリンダ内に取り込まれ、圧縮の後、高段(最終段)吐出室313に排出される。吐出冷媒ガスから分離した潤滑油は、油溜314に貯溜される。
【0078】
油溜314の潤滑油は高段(最終段)背面室316、中板306に設けた油穴368を経由して、上記実施例3と同様の差圧給油通路を通じて電動機室329に給油される。また、油溜314の潤滑油は油穴368に設けた第2絞り通路368bを介して電動機室329の底部の油溜332に戻される。
【0079】
なお、上記実施例では低段(初段)圧縮要素と高段(最終段)圧縮要素を直列接続した2段圧縮機について説明したが、各圧縮要素を順次・直列接続して、3段圧縮、4段圧縮などの多段圧縮機構に展開できる。当然のことながら、各圧縮要素の各ベーンの背面室には、上記実施例の場合と同様に、各圧縮要素の吐出圧力相当の潤滑油を導入する手段を備えた圧縮機構によって構成される。
【0080】
なお、上記実施例では二酸化炭素冷媒を使用したローリングピストン型ロータリ式2段圧縮機について説明したが、他の気体(例えば、酸素,窒素,ヘリウム,空気など)を圧縮する2段ローリングピストン型ロータリ式圧縮機の場合も同様な作用・効果を生じるものである。
【0081】
また、上記実施例では実施例1〜実施例4について個別に説明したが、2段圧縮機の運転条件や圧縮負荷条件などによって、実施例1〜実施例4の構成を適宜組み合わせることにより、一層の高効率・耐久性に優れた2段圧縮機や多段圧縮機を実現することができる。
【0082】
【発明の効果】
上記実施例から明かなように、請求項1に記載の発明は、密閉容器内に複数の圧縮要素を順次直列接続した多段圧縮機構とその多段圧縮機構の駆動軸に連結する電動機とを収納し、圧縮要素の各シリンダ内を出没(前進・後退)しつつ吸入室と圧縮室とに区画する各ベーンの内の高段(最終段)圧縮要素の高段(最終段)ベーンの高段(最終段)背面室が高段(最終段)圧縮要素の吐出側に連通する一方、低段(初段)圧縮要素の吐出側が密閉容器内に連通した構成において、高段(最終段)圧縮要素の吐出側で気体から分離した潤滑油を、高段(最終段)背面室を経由して密閉容器内に戻す絞り通路を有する油戻し通路を備えたものである。そしてこの構成によれば、高段(最終段)吐出側で吐出気体から分離した潤滑油を高段(最終段)背面室16に供給し、その潤滑油によって高段(最終段)ベーン15の摺動部隙間を潤滑・油膜密封し、高段側吐出気体が高段(最終段)ベーン15の摺動部隙間を通じてシリンダ内に流入するのを防止して圧縮効率の向上を図ると共に、高段(最終段)吐出側の潤滑油が圧縮機外部に接続する冷凍サイクル配管系を循環することなく密閉容器内1に回収できるので、冷凍サイクルへの潤滑油吐出量を少なくし、冷凍サイクル効率を向上することができる。
【0083】
請求項2に記載の発明は、高段(最終段)背面室が高段(最終段)圧縮要素の高段(最終段)吐出室の油溜を兼ねるべく構成されたものである。そしてこの構成によれば、高段(最終段)吐出室で吐出冷媒から分離した潤滑油を高段(最終段)背面室を経由して密閉容器内に回収できるので、高段(最終段)吐出室で吐出冷媒から分離されずに圧縮機外部へ排出された潤滑油も簡易な油分離手段で分離の後、再び密閉容器内に回収することが可能となる。
【0084】
請求項3に記載の発明は、油戻し通路が駆動軸を支持する軸受摺動部を経由すべく構成されたものである。そしてこの構成によれば、高段(最終段)背面室の潤滑油が駆動軸の軸受摺動部を潤滑した後、最終的に密閉容器内に回収されて、圧縮機構の外周囲を取り巻くので、その潤滑油膜によって圧縮機構部を構成する部品間の接合面を密封し、密閉容器内の気体が低段(初段)圧縮要素のシリンダ内に流入するのを防止して圧縮効率を向上させることができる。
【0085】
請求項4に記載の発明は、圧縮機構を高段圧縮要素と低段圧縮要素から成る2段圧縮機構とし、その油戻し通路は、高段圧縮要素と低段圧縮要素との間に配置した中板と、各圧縮要素のピストンの内側とを順次経由すべく設けられたものである。そしてこの構成によれば、高段(最終段)背面室の潤滑油を、高段(最終段)ベーン、各圧縮要素のピストン内側、駆動軸を支持する軸受摺動部へと順次・供給でき、効率の良い給油通路形成による潤滑油量を確保でき、圧縮室隙間の油膜密封と摺動部潤滑の併用効果によって圧縮効率と耐久性の向上を図ることができる。
【0086】
請求項5に記載の発明は、油戻し通路が、最終段圧縮要素と初段圧縮要素との間に配置した中板を経由すべく構成され、油戻し通路の絞り通路を中板に設けたものである。そしてこの構成によれば、高段(最終段)背面室から駆動軸までの適正な長さの絞り通路を有した給油通路を経由させるので、安定した絞り効果による継続的な潤滑油供給ができ、継続的な摺動部油膜形成によって耐久性向上を図ることができる。
【0087】
請求項6に記載の発明は、駆動軸を支持する軸受が少なくとも電動機に近い側に配置された主軸受を含み、油戻し通路を介して密閉容器内に流入する潤滑油の内の半分以上が主軸受の摺動部を通過すべく主軸受の軸受隙間を設定したものである。そしてこの構成によれば、電動機の磁気吸引力が駆動軸に作用して主軸受に過大負荷が作用する場合でも、密閉容器内に戻される潤滑油の内の半分以上の潤滑油供給によって、主軸受の摺動面に十分な油膜形成を可能にし、主軸受の耐久性向上を図ることができる。
【0088】
請求項7に記載の発明は、各ピストンの内側空間が最終段吐出室の圧力相当になるように軸受隙間を設定したものである。そしてこの構成によれば、各圧縮要素のシリンダ内の圧縮途中冷媒ガスが、各ピストンの内側空間に漏洩するのが阻止されるので、駆動軸を支持する主軸受の軸受摺動面へのガス噛み込みを防止して良好な軸受油膜を形成し、より一層の軸受耐久性向上を図るこたができる。
【0089】
請求項8に記載の発明は、駆動軸を支持する軸受が少なくとも電動機に近い側に配置された主軸受と電動機に遠い側に配置された副軸受とから成り、油戻し通路を介して密閉容器内に流入する潤滑油の内の大部分が主軸受と副軸受の摺動部を通過すべく油戻し通路を構成したものである。そしてこの構成によれば、高段(最終段)圧縮要素の吐出側で回収し且つ密閉容器内に戻す途中の潤滑油を軸受摺動面への給油に有効活用でき、軸受耐久性を向上させることができる。
【0090】
請求項9に記載の発明は、油戻し通路が、中板と摺接するピストンの側面を経由すべく構成されたものである。そしてこの構成によれば、高段(最終段)背面室からの潤滑油が中板とピストンとの摺接側面隙間を油膜密封し、シリンダ内の圧縮途中冷媒ガスがピストン内側に漏洩するのを防止して、圧縮効率を向上させるこたができる。
【0091】
請求項10に記載の発明は、油戻し通路が、中板に設けられたピストン摺接開口部を、圧縮要素のシリンダ内と連通せず且つピストンの側面と対向する位置に設けたものである。そしてこの構成によれば、潤滑油が中板とピストンの摺接側面を潤滑すると共に、その摺接側面を通過する潤滑油を減圧する絞り通路を簡易手段で形成し、差圧給油通路を低コストで実現できる。
【0092】
請求項11に記載の発明は、中板に設けられたピストン摺接開口部が、ピストンによって間欠的に開閉されるべく位置に配置されたものである。そしてこの構成によれば、ピストンの旋回運動速度が増加するに伴い、中板内の油通路からピストン内側に向かって通過する潤滑油の通路抵抗を増すべく、給油通路抵抗調整を行ない、高段背面室から密閉容器内へ流出させる潤滑油量調整を可能にできる。それによって、圧縮機高速運転時のごとく、冷媒速度が速くて潤滑油の分離効果が低下する場合でも、高段背面室の潤滑油を確保し、継続的な潤滑油供給をすることができる。
【0093】
請求項12に記載の発明は、ピストンの両側面に開通する軸方向貫通油穴を設け、その軸方向貫通油穴を中板に設けた摺接開口部と間欠的に連通すべく配置したものである。そしてこの構成によれば、中板内を経由した潤滑油を、中板と摺接しないピストン側面にも供給し、そのピストンの両側面隙間を油膜形成するので、シリンダ内の圧縮途中冷媒ガスがピストン内側に漏洩するのを防止し、圧縮効率の向上と、ピストンおよびピストンと摺接する部品の耐久性向上を図ることができるという効果を奏する。
【図面の簡単な説明】
【図1】本発明の第1の実施例を示すローリングピストン型ロータリ式2段圧縮機の縦断面図および吐出配管系の接続図
【図2】同圧縮機における圧縮機構部の部分断面図
【図3】図1におけるA−A線に沿った横断面図
【図4】本発明の第2の実施例を示すローリングピストン型ロータリ式2段圧縮機の部分縦断面図
【図5】図4におけるB−B線に沿った横断面図
【図6】本発明の第3の実施例を示すローリングピストン型ロータリ式2段圧縮機の部分縦断面図
【図7】同圧縮機構部の部分詳細図
【図8】同圧縮機構部のピストン外観図
【図9】本発明の第4の実施例を示すローリングピストン型ロータリ式2段圧縮機の部分縦断面図
【図10】従来のローリングピストン型ロータリ式2段圧縮機の縦断面図
【図11】同圧縮機のC−C線に沿った横断面図
【図12】別の従来のローリングピストン型ロータリ式2段圧縮機の部分断面図
【符号の説明】
1 密閉容器
2 電動機
3 2段圧縮機構
4 高段(最終段)圧縮要素
5 低段(初段)圧縮要素
7 駆動軸
9 主軸受
11 副軸受
13 高段(最終段)吐出室
14 油溜
15 高段(最終段)ベーン
16 高段(最終段)背面室
65 ピストン
68 油戻し通路
68b 絞り通路
70 ピストン
99 油分離器
204 高段(最終段)圧縮要素
205 低段(初段)圧縮要素
206 中板
206a 絞り通路
207 駆動軸
213 高段(最終段)吐出室
214 油溜
216 高段(最終段)背面室
232 油溜
265 高段(最終段)ピストン
265a 軸方向貫通油穴
270 低段(初段)ピストン
270a 軸方向貫通油穴
[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an oil supply means of a rotary multistage compressor.
[0002]
[Prior art]
Rising from recent global environmental protection problems, research and development of heat pump systems using natural refrigerants, especially carbon dioxide (CO2) refrigerants, in place of CFC refrigerants that have been used continuously has been actively conducted in various fields. ing.
[0003]
However, in the refrigeration cycle using the conventional chlorofluorocarbon refrigerant, the high pressure side is 3 MPa or less, whereas in the refrigeration cycle using the carbon dioxide (CO2) refrigerant, the low pressure side is 2.5 to 5 MPa and the high pressure side is 12 to 15 MPa. Therefore, the pressure difference between the high and low is extremely large, and there is a concern about excessive gas leakage loss during compression in the compressor cylinder.
[0004]
For these reasons, improvement studies of conventional multistage compressors are being promoted as compressors using carbon dioxide (CO2) refrigerant. In particular, as a compressor mounted in a home heat pump system, a rotary type two-stage compressor is attracting attention from the viewpoint of productivity, durability, and downsizing. Since the compressor using carbon dioxide (CO2) refrigerant has a high pressure on the high pressure side, in view of safety as a high pressure container, oil supply to the sliding portion, and compression efficiency, the inside of the sealed container that houses the electric motor, It is known that an intermediate pressure between the suction pressure and the discharge pressure is suitable.
[0005]
Such a configuration in which the inside of a sealed container that houses an electric motor is set to an intermediate pressure is represented by, for example, Japanese Patent Laid-Open No. 50-72205. Further, JP-A-2-294586, JP-A-2-294987, JP-A-7-318179 and the like have also been proposed. FIG. 10 is a longitudinal sectional view of a vertical rolling piston type rotary two-stage compressor using a chlorofluorocarbon refrigerant disclosed in Japanese Patent Laid-Open No. 2-294857, and FIG. 11 is a transverse sectional view of the compressor. FIG. 12 is a partial cross-sectional view of a laterally mounted rolling piston type rotary two-stage compressor using a chlorofluorocarbon refrigerant disclosed in JP-A-7-318179.
[0006]
10 and 11, reference numeral 1001 denotes a sealed container, 1002 denotes an electric motor part provided in the hermetic container 1001, 1003 denotes a first-stage cylinder (low-stage side cylinder block) positioned under the electric motor part 1002, and 1004 denotes one stage. A second-stage cylinder (high-stage side cylinder block) 1005 positioned below the second-stage cylinder (low-stage side cylinder block) 1003 is fixed to the hermetic container 1001, and a first-stage cylinder (low-stage side cylinder block) 1003 and two-stage An intermediate plate sandwiched between eye cylinders (higher cylinder block) 1004. Reference numeral 1006 denotes a lower bearing end plate (sub bearing) positioned below the second stage cylinder (high stage side cylinder block) 1004, and reference numeral 1007 denotes a crankshaft (drive shaft) connecting the electric motor unit 1002 and the compressor unit. Reference numeral 1008 denotes a first-stage piston (low-stage piston) that moves in a first-stage cylinder (low-stage side cylinder block) 1003, and 1009 denotes a second-stage piston (high-stage piston block that moves in a second-stage cylinder (high stage side cylinder block) 1004 (Stepped piston) 1010 is a flat plate (high-stage discharge cover). Reference numeral 1011 denotes a first-stage suction pipe (low-stage suction pipe), and 1012 denotes a second-stage discharge pipe for directly discharging the second-stage discharge refrigerant to the outside of the sealed container 1. 1013 is a second stage vane (high stage vane), 1014 is a vane spring holding the second stage vane (high stage vane) 1013, 1015 is a second stage vane (high stage vane) 1013, an intermediate plate 1005, a lower bearing. A vane back chamber (high stage back chamber) 1016 hermetically isolated from the refrigerant in the sealed container 1001 by the end plate (sub bearing) 1006 and the second stage cylinder vane groove is a lower bearing end plate (sub bearing) 1006, a flat plate ( A second stage discharge valve chamber (high stage discharge chamber) 1017 surrounded by a high stage discharge cover) 1010 includes a vane rear chamber (high stage rear chamber) 1015 and a second stage discharge valve chamber (high stage discharge chamber) 1016. It is an introductory route that communicates.
[0007]
In such a configuration, part of the refrigerant gas discharged from the second-stage discharge valve chamber (high-stage discharge chamber) 1016 is placed above the second-stage discharge valve chamber (high-stage discharge chamber) 1016 via the introduction path 1017. The vane back chamber (high-stage back chamber) 1015 is led to the vane spring and the tip of the second-stage vane (high-stage vane) 1013 is pressed against the second-stage piston (high-stage piston) 1009 with an appropriate force. While the cylinder space is partitioned into a suction side and a compression side, most of the refrigerant gas discharged from the second-stage discharge valve chamber (high-stage discharge chamber) 1016 passes through the second-stage discharge pipe 1012 to the outside of the hermetic container 1001. It is the structure discharged in.
[0008]
Further, in FIG. 12 showing a horizontal type rolling piston type rotary two-stage compressor, a rotating shaft (driving shaft) of a motor unit 2021 disposed in a hermetic case (sealed container) 2020 and its cranks 2025a and 2025b are shown. It is arranged horizontally. An oil suction hole 2052 is formed in the lower half of the intermediate bearing (middle plate) 2028 in the radial direction so as to communicate with an oil reservoir hole 2028a around the rotation shaft (drive shaft) 2025. The lower end portion 2052a is opened in the lubricating oil (oil reservoir) 2044.
[0009]
In such a configuration, the pressure in the sealed case (sealed container) 2020 in which the compressed refrigerant is discharged from the upper cylinder 2029 of the first stage compression unit on the right side, and the oil reservoir hole 2028a of the intermediate bearing (middle plate) 2028. Due to the difference, the lubricating oil 2044 is sucked up from the oil suction hole 2052 to the oil reservoir hole 2028a, and the gaps on both sides of the first stage piston roller 2031 [between the piston roller (piston) 2031 and the main bearing (main bearing) 2026 And the clearance between the piston roller (piston) 2031 and the intermediate bearing (intermediate plate) 2028] to the compression chamber and the suction side in the middle of compression in the upper cylinder 2029 of the first stage. The Thereafter, the lubricating oil mixed in the refrigerant gas discharged from the first stage compression unit into the sealed case (sealed container) 2020 is partly separated and collected in the lubricating oil 2044, but is not separated from the refrigerant gas. The remaining lubricating oil is discharged out of the sealed case (sealed container) 2020 through the second lower cylinder 2030. The lubricating oil 2044 is configured to lubricate the sliding surface partway along the path.
[0010]
[Problems to be solved by the invention]
However, such a configuration shown in FIGS. 10 and 11 has the following problems. That is, the first problem is that the refrigerant gas discharged from the vane back chamber (high-stage back chamber) 1015 leaks into the compression chamber through the sliding gap of the second-stage vane (high-stage vane) 1013, so that the compression efficiency This is a problem that the durability of the second-stage vane (high-stage vane) 1013 is difficult to ensure due to insufficient oil supply to the sliding portion minute gap of the second-stage vane (high-stage vane) 1013.
[0011]
The second problem is that the refrigerant gas discharged to the second-stage discharge valve chamber (high-stage discharge chamber) 1016 is discharged to the refrigeration cycle outside the sealed container 1001 through the second-stage discharge pipe 1012. Lubricating oil in the refrigerant gas discharged to the second-stage discharge valve chamber (high-stage discharge chamber) 1016 is not directly returned to the sealed container 1001, leading to a shortage of lubricating oil in the sealed container 1001 and to the refrigeration cycle. It is also a problem that the efficiency of the heat exchanger is reduced at the same time due to the discharge of lubricating oil.
[0012]
The third problem is that the refrigerant gas being compressed in the second-stage cylinder 1013 passes through the end surface gap of the second-stage piston 1009 (the gap between the second-stage piston 1009 and the intermediate plate 1005). A bearing sliding portion that supports the crankshaft (drive shaft) 1007 by so-called gas blow-off by leaking inside the piston 1009 (corresponding to the first-stage discharge pressure), or the crankshaft (drive shaft) 1007 and the first piston This is a problem that good lubricating oil film formation in the sliding portion between 1008 and the second piston 1009 is hindered, leading to a decrease in compressor durability.
[0013]
The configuration of the oil supply passage in the horizontal type as shown in FIG. 12 has the same problem as the third problem. That is, since the oil reservoir hole 2028a communicating with the lubricating oil 2044 and the inside of the sealed case (sealed container) 2020 have the same pressure, it is not possible to secure a sufficient differential pressure oil supply amount from the lubricating oil 2044 to the oil reservoir hole 2028a. Further, it is not possible to actively supply oil to the bearing sliding surfaces of the main bearing (main bearing) 2026 and the sub bearing (sub bearing) 2027 that support the rotating shaft (driving shaft) 2025, and the rotating shaft (driving shaft) 2025. There is a problem of securing the amount of differential pressure oil supply in the horizontal type configuration in which the inside of the sealed case (sealed container) 2020 causes intermediate pressure (intermediate pressure between the low pressure side pressure and the high pressure side pressure of the compressor).
[0014]
The present invention solves such a conventional problem, and an object of the present invention is to secure a sufficient differential pressure oil supply amount to the high-stage vane back chamber and the bearing sliding portion.
[0015]
[Means for Solving the Problems]
In order to solve the above problems, the present invention forms a differential pressure oil supply passage for returning the lubricating oil in the oil reservoir on the high-stage discharge side into the sealed container via the high-stage vane back chamber and the sliding portion of the drive shaft. Is intended. Discharge from the high-stage vane back chamber to the compression space in the cylinder by forming a differential pressure oil supply passage that passes through the high-stage vane back chamber and the sliding part of the drive shaft, and collecting and securing the lubricating oil in the sealed container. Inflow of refrigerant gas can be prevented, compression efficiency, drive shaft and vane durability, and refrigeration cycle efficiency can be improved.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
According to the first aspect of the present invention, a multistage compression mechanism in which a plurality of compression elements are sequentially connected in series in an airtight container and an electric motor connected to a drive shaft of the multistage compression mechanism are housed, and the cylinders of the compression elements are projected and retracted. Higher stage (final stage) of each vane that divides into a suction chamber and a compression chamber while moving forward and backward (high stage (final stage)) High stage (final stage) vane high stage (final stage) Lubricating oil separated from the gas on the discharge side of the high-stage (final stage) compression element in a configuration in which the discharge side of the low-stage (first stage) compression element communicates with the inside of the sealed container while communicating with the discharge side of the final stage) compression element Is provided with an oil return passage provided with a throttle passage for returning the oil to the inside of the sealed container via a high stage (final stage) back chamber. According to this configuration, the lubricating oil separated from the discharge gas on the high stage (final stage) discharge side is supplied to the high stage (final stage) back chamber, and the lubricating oil slides on the high stage (final stage) vane. Refrigeration is achieved by lubricating the oil gap and sealing the oil film to prevent the high-stage discharge gas from flowing into the cylinder through the high-stage (final stage) vane sliding gap and collecting the lubricating oil in the sealed container. The amount of lubricating oil discharged to the cycle can be reduced.
[0017]
The invention according to claim 2 is configured such that the high stage (final stage) back chamber also serves as an oil reservoir for the high stage (final stage) discharge chamber of the high stage (final stage) compression element. According to this configuration, the lubricating oil separated from the refrigerant discharged in the high-stage (final stage) discharge chamber is collected in the sealed container via the high-stage (final stage) back chamber, and the simple oil outside the compressor is collected. The separation means can be disposed.
[0018]
According to a third aspect of the present invention, the oil return passage is configured to pass through a bearing sliding portion that supports the drive shaft. And according to this structure, after the lubricating oil of the high-stage (final stage) back chamber lubricates the bearing sliding part of a drive shaft, it is finally collect | recovered in an airtight container, and surrounds the outer periphery of a compression mechanism. As a result, the lubricating oil film seals the joint surfaces between the parts constituting the compression mechanism, and the gas in the sealed container can be prevented from flowing into the cylinder of the low-stage (first stage) compression element.
[0019]
In the invention according to claim 4, the compression mechanism is a two-stage compression mechanism including a high-stage compression element and a low-stage compression element, and the oil return passage is disposed between the high-stage compression element and the low-stage compression element. It is provided so as to pass through the intermediate plate and the inside of the piston of each compression element sequentially. According to this configuration, the lubricating oil in the high-stage (final stage) back chamber is sequentially supplied to the high-stage (final stage) vane, the inside of the piston of each compression element, and the bearing sliding portion that supports the drive shaft. A good oil supply passage can be formed.
[0020]
According to a fifth aspect of the present invention, the oil return passage is configured to pass through a middle plate disposed between the final stage compression element and the first stage compression element, and a throttle passage is provided in the middle plate. According to this configuration, it is possible to continuously supply lubricating oil with a stable throttling effect through an oil supply passage having an appropriate distance from the high-stage (final stage) back chamber to the drive shaft.
[0021]
According to a sixth aspect of the present invention, the bearing supporting the drive shaft includes a main bearing disposed at least on the side close to the electric motor, and more than half of the lubricating oil flowing into the sealed container via the oil return passage is formed. The bearing clearance of the main bearing is set so as to pass through the sliding portion of the main bearing. According to this configuration, even when the magnetic attraction force of the electric motor acts on the drive shaft and an excessive load acts on the main bearing, the main oil is supplied by more than half of the lubricating oil returned to the sealed container. A sufficient oil film can be formed on the sliding surface of the bearing.
[0022]
According to the seventh aspect of the present invention, the bearing gap is set so that the inner space of each piston corresponds to the pressure in the final stage discharge chamber. According to this configuration, the refrigerant gas in the cylinder of each compression element is prevented from leaking into the inner space of each piston, and gas is caught in the bearing sliding surface of the main bearing that supports the drive shaft. Can be prevented.
[0023]
According to an eighth aspect of the present invention, the bearing for supporting the drive shaft includes at least a main bearing disposed on the side close to the electric motor and a sub-bearing disposed on the side far from the electric motor. An oil return passage is configured so that most of the lubricating oil flowing in passes through the sliding portions of the main bearing and the sub-bearing. According to this configuration, the lubricating oil collected on the discharge side of the high-stage (final stage) compression element and returned to the sealed container is effectively used for oil supply to the bearing sliding surface, improving the bearing durability. Can be made.
[0024]
According to the ninth aspect of the present invention, the oil return passage is configured to pass through the side surface of the piston that is in sliding contact with the intermediate plate. According to this configuration, the lubricating oil from the back chamber of the upper stage (final stage) seals the sliding surface of the middle plate and the piston with an oil film, and prevents refrigerant gas from being leaked into the piston during compression in the cylinder. it can.
[0025]
According to a tenth aspect of the present invention, the oil return passage is provided at a position where the piston sliding contact opening provided in the intermediate plate does not communicate with the inside of the cylinder of the final stage compression element and faces the side surface of the final stage piston. It is what was done. According to this configuration, the lubricating oil can lubricate the sliding contact side surfaces of the intermediate plate and the final stage piston, and the throttle passage for reducing the pressure of the lubricating oil passing through the sliding contact side surfaces can be formed by simple means.
[0026]
According to the eleventh aspect of the present invention, the piston sliding contact opening provided in the intermediate plate is arranged at a position so as to be intermittently opened and closed by the final stage piston. According to this configuration, as the turning speed of the piston increases, the oil supply passage resistance adjustment is performed so that the passage resistance of the lubricating oil passing from the oil passage in the intermediate plate toward the inside of the piston increases. It is possible to adjust the amount of lubricating oil flowing out from the back (last stage) back chamber into the sealed container.
[0027]
According to a twelfth aspect of the present invention, through oil holes are provided on both side surfaces of the final stage piston, and the through oil holes are arranged to intermittently communicate with sliding contact openings provided in the intermediate plate. . According to this configuration, the lubricating oil that has passed through the inside of the intermediate plate is also supplied to the side surface of the piston that is not in sliding contact with the intermediate plate, and the refrigerant gas in the cylinder leaks inside the piston due to the formation of an oil film on the side surface of the piston. Can be prevented.
[0028]
Embodiments of the present invention will be described below with reference to the drawings.
[0029]
Example 1
1 represents a longitudinal section of a rolling piston type rotary two-stage compressor using carbon dioxide refrigerant, FIG. 2 represents a partial longitudinal section of the two-stage compression mechanism in FIG. 1, and FIG. The cross section along A line is represented.
[0030]
Inside the hermetic container 1, an electric motor 2 and a two-stage compression mechanism 3 are disposed below the electric motor 2.
The two-stage compression mechanism 3 includes a high-stage (final stage) compression element 4, a low-stage (first stage) compression element 5, a high-stage (final stage) compression element 4, and a low-stage (first stage) compression element. An intermediate plate 6 disposed between the elements 5, a drive shaft 7 connected to the rotor 2a of the electric motor 2 to drive the high-stage (final stage) compression element 4 and the low-stage (first stage) compression element 5, The main bearing 9 fixed to the high-stage (final stage) side cylinder block 8 of the high-stage (final stage) compression element 4 and the low-stage (first stage) side of the low-stage (first stage) compression element 5 to support the drive shaft 7 The auxiliary bearing 11 is fixed to the cylinder block 10.
[0031]
A high-stage (final stage) discharge cover 12 that is fixed to the high-stage (final stage) side cylinder block 8 and whose outer periphery is welded to the sealed container 1 surrounds the cylinder block mounting flange portion 9a of the main bearing 9 and A high-stage (final stage) discharge chamber 13 is formed so as to surround the outer peripheral portion of the bearing body 9b. The bottom of the high-stage (final stage) discharge chamber 13 forms an oil reservoir 14, which is in constant communication with a high-stage (final stage) back chamber 16 formed on the side of the high-stage (final stage) vane 15 on the side opposite to the compression chamber. Yes.
[0032]
The high-stage (final stage) back chamber 16 is connected to the downstream side of the check valve means 98 that is disposed in the discharge piping system outside the compressor and allows refrigerant flow only from the compressor toward the radiator. It is connected to the bottom of the oil separator 99 and communicates with an oil return pipe 152 that passes through the side wall of the hermetic container 1 and is inserted into the high-stage cylinder block 8. A spring case 64 is press-fitted into the high-stage cylinder block 8. The spring case 64 includes a high stage (final stage) vane spring 66 that urges the high stage (final stage) vane 15 toward the high stage (final stage) piston 65 constituting the high stage (final stage) compression element 4, and A valve element 67 made of a steel ball that opens and closes the opening end passage of the oil return pipe 152 is accommodated. The high-stage (final stage) vane spring 66 urges the valve body 67 toward the oil return pipe 152 to close the opening end passage of the oil return pipe 152. Further, the high-stage (final stage) vane spring 66 has a shape memory characteristic in which the spring constant increases with its own temperature rise, while the spring constant decreases with its own temperature drop.
[0033]
The high-stage (final stage) discharge chamber 13 discharges the discharged refrigerant gas formed through the discharge pipe 19 that is raised and fixed to the cylinder block mounting flange portion 9a of the main bearing 9 and penetrates the side wall of the sealed container 1. The passage 20 leads to the compressor external discharge piping system 21. A discharge port 22 that opens in the compression chamber of the high-stage (final stage) compression element 4 provided in the main bearing 9 is a discharge valve device 24 that is mounted in a discharge valve chamber 23 that is recessed in the cylinder block mounting flange portion 9a. Is opened and closed by. The discharge port side end of the discharge valve chamber 23 has a high-stage (final stage) rear surface so that the lubricating oil discharged from the discharge port 22 together with the refrigerant gas discharged from the compression chamber can easily flow into the high-stage (final stage) back chamber 16. It is arranged toward the chamber 16.
[0034]
The low stage (first stage) discharge cover 26 fixed to the low stage (first stage) side cylinder block 10 together with the sub bearing 11 forms a low stage (first stage) discharge chamber 27 together with the sub bearing 11. The low-stage (first stage) discharge chamber 27 sequentially communicates the auxiliary bearing 11, the low-stage (first stage) cylinder block 10, the middle plate 6, the high-stage (final stage) cylinder block 8, and the high-stage (final stage) discharge cover 12. The motor chamber 29 in which the motor 2 is housed is communicated via the intermediate gas passage 28 formed in this manner.
[0035]
The end of the intermediate gas passage 28 is close to the coil end 2 c of the electric motor 2 by the discharge pipe 39 attached to the high-stage (final stage) discharge cover 12. An intermediate suction pipe 39 a that opens in the vicinity of the coil end 2 c at a position opposite to the discharge pipe 39 communicates with the suction side of the high-stage compression element 4. The oil reservoir 32 at the bottom of the hermetic container 1 and the electric motor chamber 29 communicate with each other via an oil dropping hole 33 (see FIG. 3) provided in the high-stage (final stage) discharge cover 12.
[0036]
The lower (first stage) back chamber 33 of the lower stage (first stage) compression element 5 communicates with the oil reservoir 32 via a vane spring mounting hole 34. The high-stage (final stage) back chamber 16 is provided in the middle plate 6 and communicates with the inside of the sealed container 1 through a throttle passage 68b formed by a screw groove gap with one end screwed, while the other end is opened. The fine hole 68 leads to the inner space of the final (higher) piston 65.
[0037]
The operation of the rolling piston type rotary two-stage compressor using the carbon dioxide refrigerant gas configured as described above will be described.
[0038]
The refrigerant gas taken into the cylinder of the low-stage (first-stage) compression element 5 through the low-stage (first-stage) suction pipe 36 that penetrates the side wall of the hermetic container 1 is discharged from the oil reservoir 32 through the extremely small holes 35 provided in the auxiliary bearing 11. After the reduced-pressure introduced lubricating oil is compressed in a mixed state, it is discharged to the low-stage (first stage) discharge chamber 27 and then discharged to the electric motor chamber 29 via the intermediate gas passage 28 and the discharge pipe 39. The lubricating oil taken into the cylinder of the low-stage (first stage) compression element 5 together with the intake refrigerant gas is used for sealing an oil film in a minute gap in the compression chamber, and contributes to prevention of refrigerant gas leakage during compression.
[0039]
The refrigerant gas that has flowed into the motor chamber 29 collides with the coil end 2c. At that time, the lubricating oil mixed in the refrigerant gas is separated. Thereafter, the refrigerant gas is taken into the cylinder of the high-stage (final stage) compression element 4 through the intermediate suction pipe 39a. The lubricating oil mixed in the refrigerant gas is separated by the flow of the refrigerant gas along the coil end 2c, and the electric motor 2 is cooled.
[0040]
The lubricating oil that has not been separated from the refrigerant gas in the motor chamber 29 or a part of the lubricating oil that has accumulated in the vicinity of the upper opening end of the intermediate suction pipe 39a with the oil surface of the oil reservoir 32 is high-stage (final) Stage) It is taken into the cylinder of the compression element 4 and is discharged from the discharge port 22 to the higher stage (final stage) discharge chamber 13 after being compressed with the refrigerant gas.
[0041]
A part of the refrigerant gas discharged from the discharge port 22 flows along the discharge valve chamber 23 toward the high-stage (final stage) back chamber 16 and collides with the inner wall surface of the high-stage (final stage) discharge cover 12. A part of the lubricating oil mixed in the refrigerant gas is separated and flows into the upper (last stage) back chamber 16. The remaining refrigerant gas discharged from the discharge port 22 collides with the entire inner wall surface of the high-stage (final stage) discharge cover 12, and the lubricating oil separated from the refrigerant gas is the outer periphery of the cylinder block mounting flange portion 9 a of the main bearing 9. Is collected in an oil reservoir 14 configured with an annular oil groove 14a provided in a high-stage (final-stage) side cylinder block so as to surround the high-stage (final-stage) back chamber 16 disposed below the annular oil groove 14a.
[0042]
The lubricating oil in the high-stage (final stage) back chamber 16 is pumped by the reciprocating motion of the high-stage (final stage) vane 15 and enters and leaves the oil surface side and the bottom surface side of the oil reservoir 14. On the other hand, a part of the lubricating oil in the high-stage (final stage) back chamber 16 is returned to the hermetic container 1 through the throttle passage 68 b provided in the intermediate plate 6, and the high-stage (final stage) back chamber 16. Most of the lubricant oil flows into the inner space of the high-stage (final stage) piston 65 and the low-stage (first stage) piston 70 through the oil hole 68, and then the bearing sliding portion 9c of the main bearing 9 and the sub-bearing 11 The pressure is reduced while passing through the minute bearing gaps of each of the bearing sliding portions 11 c, and the differential pressure is supplied to the motor chamber 29.
[0043]
In addition, when the lubricating oil passes through the bearing gap between the main bearing 9 and the auxiliary bearing 11 and flows into the motor chamber 29, the lubricating oil passes through the bearing gap of the main bearing 9 more than the bearing gap of the auxiliary bearing 11, The passage resistance of the bearing gap of both bearings is set, and sufficient oil supply to the main bearing is performed. As a result, an excellent oil film can be formed and the bearing sliding surface can be cooled against vibration and overload acting on the main bearing 9 due to the unbalance of the rotor of the motor connected to the drive shaft.
[0044]
Further, the lubricating oil supplied to the inner space of the high-stage (final stage) piston 65 and the low-stage (first stage) piston 70 is slid between the high-stage (final stage) piston 65, the main bearing 9, and the middle plate 6. The moving gap (piston side gap), the low stage (first stage) piston 70, the sub-bearing 11 and the intermediate plate 6 are respectively slidable gaps (piston side gap), and the high stage (final stage) compression element 4 and low It is also taken into each cylinder of the stage (first stage) compression element 5.
[0045]
Lubricating oil supplied with differential pressure from the high-stage (final stage) back chamber 16 into the motor chamber 29 and the cylinders of the compression elements (4, 5) is provided for sliding surface lubrication along the path. The discharged refrigerant gas discharged from the high-stage (final stage) discharge chamber 13 through the discharge pipe 19 to the outside of the compressor is separated from the lubricating oil through an oil separator 99 arranged on the upstream side of a radiator (not shown). The oil is stored in the oil reservoir 99a at the bottom.
[0046]
The lubricating oil of the oil separator 99 arranged at a position higher than the oil reservoir 32 is in a state where the refrigeration cycle after the compressor is stopped is in a state where the pressure in the refrigeration cycle is equalized. In the state where the biasing force of the vane spring is weak], the closing function of the valve body 67 is lowered, and the lubricating oil itself flows into the high stage (final stage) back chamber 16 through the oil return pipe 152. Further, due to the check action of the check valve means 98 disposed between the compressor and the oil separator 99, the pressure equalization pressure in the compressor immediately after the compressor is stopped and the differential pressure between the oil separator 99 are also obtained. Lubricating oil in the oil separator 99 is returned to the upper stage (final stage) back chamber 16. During the operation of the compressor, the lubricating oil in the oil separator 99 is compressed by the valve element 67 closing the open end of the oil return pipe 152 (received by the micro spring biasing force of the high stage (final stage) vane spring). There is no return to the plane.
[0047]
The lubricating oil returned from the oil separator 99 to the high stage (final stage) back chamber 16 while the compressor is stopped is divided into an oil hole 68 provided in the intermediate plate 6, a high stage (final stage) piston 65, and a low stage (first stage). It finally returns to the oil reservoir 32 via the inner space of the piston 70.
[0048]
As described above, according to the above embodiment, the two-stage compression mechanism 3 in which the low-stage (first stage) compression element 5 and the high-stage (final stage) compression element 4 are connected in series in the hermetic container 1 and the two-stage compression mechanism 3. The motor 2 connected to the drive shaft 7 is housed, and a high stage (in each vane that partitions into a suction chamber and a compression chamber while moving forward and backward in each cylinder of each compression element 4, 5 ( The high-stage (final stage) back chamber 16 and the high-stage (final stage) discharge chamber 13 of the high-stage (final stage) vane 15 of the final stage) compression element 4 communicate with the low-stage (first stage) compression element 5. In the configuration in which the discharge side is in communication with the sealed container 1, the lubricating oil separated from the gas on the discharge side of the high-stage (final stage) compression element 4 is passed through the high-stage (final stage) back chamber 16 in the closed container 1. Provided with an oil return passage 68 and a throttle passage 68b having a throttle passage (bearing gap between the main bearing 9 and the sub-bearing 11). As a result, the lubricating oil separated from the discharge gas on the high stage (final stage) discharge chamber 13 side is supplied to the high stage (final stage) back chamber 16, and the lubricating oil is slid on the high stage (final stage) vane 15. The moving part gap is lubricated and the oil film is sealed, and the high stage side discharge gas is prevented from flowing into the cylinder through the sliding part gap of the high stage (final stage) vane 15, and the high stage (final stage) compression element 4 is compressed. Efficiency can be improved. Further, when the compressor is stopped, the lubricating oil in the oil reservoir 99a of the oil separator 99 is collected in the sealed container 1 through the oil return pipe 152, thereby reducing the amount of lubricating oil discharged to the refrigeration cycle. Thus, the efficiency of the refrigeration cycle can be improved by improving the efficiency of the heat exchanger.
[0049]
Further, according to the above embodiment, the high stage (final stage) back chamber 16 is configured to serve as the oil reservoir 14 of the high stage (final stage) discharge chamber 13 of the high stage (final stage) compression element 4. Since the lubricating oil separated from the refrigerant discharged in the high-stage (final stage) discharge chamber 13 can be recovered in the sealed container 1 via the high-stage (final stage) back chamber 14, the high-stage (final stage) discharge chamber 13 Lubricating oil discharged from the compressor without being separated from the refrigerant gas can be easily separated in the oil separator 99 having a simple configuration, and recovered in the sealed container 1 in an in-machine pressure balanced state after the compressor is stopped. It is possible to secure durability by securing the amount of oil in the compressor.
[0050]
Further, according to the above embodiment, the oil return passage 68 is configured to pass through the bearing sliding portions of the main bearing 9 and the auxiliary bearing 11 that support the drive shaft 7. After the lubricating oil of the above has lubricated the bearing sliding portion of the drive shaft 7, it is finally collected in the sealed container 1 and surrounds the outer periphery of the compression mechanism, so that the lubricating oil film constitutes the multistage compression mechanism portion 3. It is possible to improve the compression efficiency by sealing the interface between them and preventing the gas in the sealed container 1 from flowing into the cylinder of the low-stage (first stage) compression element 5.
[0051]
According to the above embodiment, the compression mechanism is the two-stage compression mechanism 3 including the high-stage compression element 5 and the low-stage compression element 4, and the lubricating oil separated in the high-stage discharge chamber 13 passes through the high-stage back chamber 16. An oil return passage 68 that returns to the sealed container 1 connects the middle plate 6 disposed between the high-stage compression element 5 and the low-stage compression element 4 and the insides of the pistons 65 and 70 of the compression elements 4 and 5. By providing them in order, the lubricating oil in the high-stage back chamber 16 causes the high-stage vanes 15, the pistons 65 and 70 inside the compression elements, and the bearings of the main bearing 9 and the auxiliary bearing 11 that support the drive shaft 7. Since an efficient oil supply passage to be sequentially supplied to the sliding portion can be formed, the amount of lubricating oil mixed in the refrigerant gas can be reduced to avoid oil compression in the cylinder and reduce the compression input.
[0052]
Further, according to the above embodiment, the bearing supporting the drive shaft 7 includes at least the main bearing 9 disposed on the side close to the electric motor 2, and the inside of the lubricating oil flowing into the hermetic container 1 through the oil return passage 68. Since the bearing clearance of the main bearing 9 is set so that more than half of it passes through the sliding portion of the main bearing 9, the magnetic attraction force of the electric motor 2 acts on the drive shaft 7 and an overload acts on the main bearing 9. Even in this case, by supplying more than half of the lubricating oil returned to the hermetic container 1, a sufficient oil film can be formed on the sliding surface of the main bearing 9 to improve bearing durability. it can.
[0053]
Further, according to the above embodiment, the bearing gap is set so that the inner space of each piston 65, 70 corresponds to the pressure in the high-stage (final stage) discharge chamber 13, so that the inside of the cylinder of each compression element 4, 5 The refrigerant gas in the middle of compression is prevented from leaking into the inner space of each piston 65, 70, and the gas sliding into the bearing sliding surface of the main bearing 9 that supports the drive shaft 7 is prevented. Oil film formation improves bearing durability and reduces compressor input by reducing bearing friction loss.
[0054]
According to the above embodiment, the bearing that supports the drive shaft 7 includes at least the main bearing 9 disposed on the side close to the electric motor 2 and the auxiliary bearing 11 disposed on the side far from the electric motor 2, and the oil return passage 68. The oil return passage 68 is configured so that most of the lubricating oil flowing into the sealed container 1 via the sliding portion of the main bearing 9 and the sub-bearing 11 is compressed, so that the high-stage (final stage) compression is performed. The lubricating oil collected on the discharge side of the element 4 and returned to the sealed container 1 is effectively used for supplying oil to the bearing sliding surface, and the bearing durability can be improved.
[0055]
(Example 2)
FIG. 4 shows a partial longitudinal sectional view of a rolling piston type rotary two-stage compressor using a carbon dioxide refrigerant, in which the compressor is configured horizontally. FIG. 5 is a transverse section taken along the line BB in FIG. Represents the figure.
[0056]
Inside the hermetic container 101, an electric motor 102 and a two-stage compression mechanism 103 are arranged on the side thereof. That is, the low-stage (first stage) compression element 105 of the two-stage compression mechanism 103 is disposed on the motor 102 side, and the high-stage (final stage) compression element 104 is disposed on the counter-motor side. The lower stage (first stage) side cylinder block 110 of the lower stage (first stage) compression element 105 is welded and fixed to the hermetic container 101, and a main bearing 109 that supports the drive shaft 107 fixed to the lower stage (first stage) cylinder block 110. Is arranged on the motor side, while the intermediate plate 106, the high stage (final stage) side cylinder block 108, the auxiliary bearing 111 that supports the drive shaft 107, and the high stage (final stage) discharge cover are sequentially arranged on the counter motor side.・ It is arranged.
[0057]
The discharge port 173 of the low-stage (first stage) compression element 105 disposed in the main bearing 109 opens directly into the motor chamber 129. The suction refrigerant gas taken into the cylinder of the high-stage (final stage) compression element 104 is attached to the high-stage (final stage) discharge cover 126 and the opening end to the motor chamber 129 is at a position higher than the axis of the drive shaft 107. It is configured to be introduced through an intermediate suction pipe 139a provided in the. The high-stage (final stage) discharge chamber 113 communicates with the compressor external discharge piping system 121 via the sub-bearing 111 and the discharge gas discharge passage 120 provided in the high-stage (final stage) side cylinder block 108.
[0058]
The low-stage (first stage) back chamber 133 of the low-stage (first stage) compression element 105 and the high-stage (final stage) back chamber 116 of the high-stage (final stage) compression element 104 are disposed below the drive shaft 107. The lower (first) rear chamber 133 communicates with the oil reservoir 132. The high-stage (final stage) back chamber 116 communicates with the bottom of an oil reservoir 114 provided at the bottom of the high-stage (final stage) discharge chamber 113. The bottom part of the vane spring mounting hole 134 a of the lower stage (first stage) rear chamber 133 communicates with the end oil reservoir space 171 of the drive shaft 107 through an oil hole 168 provided in the auxiliary bearing 111.
[0059]
The oil reservoir space 171 at the end of the drive shaft 107 communicates with the motor chamber 129 via a shaft hole 172 provided in the drive shaft 107 and a minute bearing gap of the main bearing 109 that supports the drive shaft 107 in order. Other configurations are the same as or similar to those in the first embodiment, and a description thereof will be omitted.
[0060]
The operation of the rolling piston type rotary two-stage compressor using the carbon dioxide refrigerant gas configured as described above will be described with reference to FIGS.
[0061]
The refrigerant gas taken into the low-stage (first stage) compression element 105 from the low-stage suction pipe 136 is discharged into the electric motor chamber 129 after compression, and most of the lubricating oil is separated from the refrigerant gas. Thereafter, the refrigerant gas cools the outer periphery of the two-stage compression mechanism 103, and after the lubricating oil is further separated, the refrigerant gas is taken into the high-stage (final stage) compression element 104 via the intermediate suction pipe 139a. Thereafter, the refrigerant is discharged to the outside of the compressor through the high-stage (final stage) discharge chamber 113 and the discharge refrigerant gas discharge passage 120 in order.
[0062]
Lubricating oil separated from the refrigerant gas due to collision of the refrigerant gas discharged into the high-stage (final stage) discharge chamber 113 with the inner wall of the high-stage (final stage) discharge cover 112 is removed from the high-stage (final stage) discharge cover. The oil flows through the inner wall of 112, and flows down to the lower oil reservoir 132, the upper (final) rear chamber 116, and the vane spring mounting hole 134.
[0063]
As the high-stage (final stage) vane 115 advances / retreats toward the high-stage (final stage) piston 165, the lubricating oil in the high-stage (final stage) back chamber 116 and the vane spring mounting hole 134 receives a pump action. By this pump action, the lubricating oil in the high-stage (final stage) back chamber 116 is properly supplied into the cylinder via the sliding surface of the high-stage (final stage) vane 115. At the same time, due to this pump action, the lubricating oil in the vane spring mounting hole 134 is supplied to the shaft end oil reservoir 171 via the oil hole 168 provided in the auxiliary bearing 111.
[0064]
Lubricating oil in the shaft end oil reservoir 171 passes through the shaft hole 172 to the auxiliary bearing 111, the high (last) piston 165, the low (first) piston 170, and the main bearing 109. A differential pressure is supplied to the electric motor chamber 129 via the sliding surface. When passing through the minute bearing gap of the main bearing 109, the lubricating oil corresponding to the high stage (final stage) discharge pressure is reduced. Therefore, the lubricating oil in the space inside the low-stage (first stage) piston 170 maintains a pressure corresponding to the high-stage (final stage) discharge pressure.
[0065]
According to the above embodiment, the two-stage compression mechanism 103 in which the low-stage (first stage) compression element 105 and the high-stage (final stage) compression element 104 are connected in series in the sealed container 101 and the drive shaft 107 of the two-stage compression mechanism 103. The motor 102 connected to the compressor is housed, and the high-stage (final stage) compression in each vane that partitions into the suction chamber and the compression chamber while projecting (advancing and retreating) in the cylinders of the compression elements 104 and 105 The high stage (final stage) back chamber 116 of the high stage (final stage) vane 115 of the element 104 communicates with the high stage (final stage) discharge chamber 113 while the discharge side of the low stage (first stage) compression element 105 is a sealed container. 101, a throttle passage that returns the lubricating oil separated from the gas on the discharge side of the high-stage (final stage) compression element 104 to the inside 101 of the sealed container via the high-stage (final stage) back chamber 116. (Main bearing 109 and secondary bearing 111 By providing the oil return passage 168 with the bearing clearance), the lubricating oil separated from the discharge gas on the high-stage (final stage) discharge chamber 113 side is supplied to the high-stage (final stage) back chamber 116 and lubricated. Oil lubricates and seals the oil gap in the sliding part of the high stage (final stage) vane 115 and prevents the high-stage discharge gas from flowing into the cylinder through the sliding part gap of the high stage (final stage) vane 115. In addition to improving the compression efficiency of the high-stage (final stage) compression element 104, the amount of lubricating oil discharged into the closed container 101 is recovered, thereby reducing the amount of lubricating oil discharged into the refrigeration cycle and improving the efficiency of the heat exchanger. By doing so, the efficiency of the refrigeration cycle can also be improved.
[0066]
(Example 3)
FIG. 6 is a partial longitudinal sectional view in which the differential pressure oil supply passage in the second embodiment is configured through an oil hole 268 provided in the intermediate plate 206 in a rolling piston type rotary two-stage compressor using carbon dioxide refrigerant. FIG. 7 shows a partially enlarged view of the oil supply passage, and FIG. 8 shows the appearance of the piston.
[0067]
That is, the high stage (final stage) back pressure chamber 216 has a space inside the high stage (final stage) piston 265 and the low stage (first stage) piston 270 via the vane spring mounting hole 234a and the oil hole 268 provided in the intermediate plate 206. In addition, the motor chamber 229 communicates with a small bearing gap between the main bearing 209 and the sub-bearing 211 that support the drive shaft 207. Lubricating oil in the high-stage (final stage) back pressure chamber 216 is supplied with differential pressure through the above-described passages while being sequentially reduced in pressure in a throttle passage described below.
[0068]
Lubricating oil in the high-stage (final stage) back pressure chamber 216 is disposed in the first throttle passage 268a disposed in the middle of the oil hole 268 and downstream of the oil hole 268, and the high-stage (final stage) back pressure chamber 216 A second throttle passage 268c (see FIG. 7) provided to open toward the middle plate sliding contact surface of the stage (final stage) piston 265, and an axial oil hole 270a provided in the low stage (first stage) piston 270. (See FIGS. 7 and 8) and the axial oil holes 265a (see FIGS. 7 and 8) provided in the high-stage (final stage) piston 265, the pressure is sequentially reduced.
[0069]
The second throttle passage 268c, the axial through oil hole 270a, and the axial through oil hole 265a are formed by the swiveling motion of the low-stage (first stage) piston 270 and the high-stage (final stage) piston 265. Communicate intermittently. Due to this intermittent communication, the lubricating oil is subjected to a pressure reducing action. The lubricating oil that has passed through the axial oil hole 270a and the axial oil hole 265a is slidably contacted between the low stage (first stage) piston 270 and the main bearing 209, and between the high stage (final stage) piston 265 and the auxiliary bearing 211. The contact surface is lubricated and supplied to the inner space of the low-stage (first stage) piston 270 and the high-stage (final stage) piston 265.
[0070]
Accordingly, the lubricating oil in the oil hole 268 is supplied to the motor chamber 229 with a differential pressure while lubricating the sliding surfaces passing through the low-stage (first stage) piston 270, the high-stage (final stage) piston 265, and the drive shaft 207. Further, the lubricating oil in the high-stage (final stage) back pressure chamber 216 is returned to the oil reservoir 232 at the bottom of the motor chamber 229 through a third throttle passage provided in the intermediate plate 206. Other configurations are the same as those in the above embodiment, and thus the description thereof is omitted.
[0071]
According to the above embodiment, the oil return passage from the oil reservoir 214 of the high-stage (final stage) discharge chamber 213 to the oil reservoir 232 in the hermetic container has the high-stage (final stage) compression element 204 and the low-stage (first stage). The intermediate plate 206 is disposed between the compression element 205 and a throttle passage 206a is provided in the intermediate plate 206 so as to set an appropriate throttle passage length. To the drive shaft 207 can be continuously supplied with a stable squeezing effect, and the durability of the sliding contact surface can be improved.
[0072]
Further, according to the above embodiment, the oil return passage from the oil reservoir 214 of the high-stage (final stage) discharge chamber 213 to the oil reservoir 232 in the sealed container has a low-stage (first-stage) piston 270 that is in sliding contact with the intermediate plate 206. By being configured to pass through the side surface of the high-stage (final stage) piston 265, the lubricating oil from the high-stage (final stage) back chamber 216 receives the middle plate 206, the low-stage (first stage) piston 270, and the high stage (final stage). Step) The sliding contact side face with the piston 265 is sealed with an oil film, and the refrigerant gas in each cylinder can be prevented from leaking to the inside of each piston to improve the compression efficiency.
[0073]
Further, according to the above embodiment, the oil return passage from the oil reservoir 214 of the high-stage (final stage) discharge chamber 213 to the oil reservoir 232 in the sealed container is provided by each piston (265, 270) provided in the intermediate plate 206. The sliding contact opening is not communicated with the inside of the cylinder of the high-stage (final stage) compression element 204 and is provided at a position facing the side surfaces of the low-stage (first stage) piston 270 and the high-stage (final stage) piston 265. As a result, the lubricating oil lubricates the sliding contact side surfaces of the intermediate plate 206, the low-stage (first stage) piston 270, and the high-stage (final stage) piston 265, and the throttle passage for reducing the pressure of the lubricating oil passing through the sliding contact side faces. Cost reduction can be achieved by simple means.
[0074]
Further, according to the above embodiment, the sliding contact openings of the pistons (265, 270) provided in the intermediate plate 206 are arranged at positions to be opened and closed intermittently by the pistons (265, 270). As the rotational speed of each piston (265, 270) increases, the oil supply passage increases so that the passage resistance of the lubricating oil passing from the oil passage in the intermediate plate 206 toward the inside of each piston (265, 270) increases. The resistance adjustment is performed, and the adjustment of the amount of lubricating oil flowing out from the high stage (final stage) back chamber 216 into the sealed container can be realized by following the compressor operating speed.
[0075]
Further, according to the above embodiment, the axial through oil hole 270a and the axial through oil hole 265a that are opened on both side surfaces of the low stage (first stage) piston 270 and the high stage (final stage) piston 265 are provided. Since the hole 270a and the axial through oil hole 265a are disposed so as to intermittently communicate with a sliding contact opening provided in the intermediate plate 206, the lubricating oil passing through the intermediate plate 206 is in sliding contact with the intermediate plate 206. It is also supplied to the side surface of each piston (265, 270) not to be formed, and by forming an oil film on the side surface of the piston, it is possible to prevent the refrigerant gas in the cylinder during compression from leaking inside the piston and improve the compression efficiency.
[0076]
(Example 4)
FIG. 9 is a partial longitudinal sectional view showing a rolling piston type rotary two-stage compressor using a carbon dioxide refrigerant, in which the two-stage compression mechanism and the electric motor according to the first embodiment are horizontally arranged.
[0077]
In other words, the intermediate suction pipe 339 a is arranged to communicate with the suction side of the high-stage (final stage) compression element 304. In the above configuration, the refrigerant gas compressed by the low-stage (first-stage) compression element 305 is discharged into the motor chamber 329, and then is cooled through the intermediate suction pipe 339a while cooling the outer surface of the two-stage compression mechanism. It is taken into the cylinder of the stage (final stage) compression element 304 and is discharged into the high stage (final stage) discharge chamber 313 after compression. The lubricating oil separated from the discharged refrigerant gas is stored in the oil reservoir 314.
[0078]
Lubricating oil in the oil reservoir 314 is supplied to the motor chamber 329 through the high pressure (final stage) back chamber 316 and the oil hole 368 provided in the intermediate plate 306 through the differential pressure oil supply passage similar to that in the third embodiment. . Further, the lubricating oil in the oil reservoir 314 is returned to the oil reservoir 332 at the bottom of the motor chamber 329 through the second throttle passage 368 b provided in the oil hole 368.
[0079]
In the above embodiment, a two-stage compressor in which a low-stage (first stage) compression element and a high-stage (final stage) compression element are connected in series has been described. It can be developed in a multistage compression mechanism such as four-stage compression. As a matter of course, the back chamber of each vane of each compression element is constituted by a compression mechanism provided with means for introducing lubricating oil corresponding to the discharge pressure of each compression element, as in the case of the above embodiment.
[0080]
In the above embodiment, a rolling piston type rotary two-stage compressor using carbon dioxide refrigerant has been described. However, a two-stage rolling piston type rotary that compresses other gases (for example, oxygen, nitrogen, helium, air, etc.). In the case of the type compressor, the same action and effect are produced.
[0081]
Moreover, although the said Example demonstrated individually about Example 1-Example 4, by combining the structure of Example 1-Example 4 suitably according to the operating conditions, compression load conditions, etc. of a two-stage compressor, it was further. It is possible to realize a two-stage compressor and a multi-stage compressor excellent in high efficiency and durability.
[0082]
【The invention's effect】
As apparent from the above embodiment, the invention according to claim 1 houses a multistage compression mechanism in which a plurality of compression elements are sequentially connected in series in a sealed container and an electric motor connected to a drive shaft of the multistage compression mechanism. , High-stage (final stage) of high-stage (final stage) vane (high-stage) of each vane partitioning into a suction chamber and a compression chamber while appearing (advancing and retreating) in each cylinder of the compression element (high-stage (final stage)) (Last stage) The back chamber communicates with the discharge side of the high stage (final stage) compression element, while the discharge side of the low stage (first stage) compression element communicates with the inside of the sealed container. An oil return passage having a throttle passage for returning the lubricating oil separated from the gas on the discharge side to the inside of the sealed container through the higher stage (final stage) back chamber is provided. According to this configuration, the lubricating oil separated from the discharge gas on the high-stage (final stage) discharge side is supplied to the high-stage (final stage) back chamber 16, and the high-stage (final stage) vane 15 is supplied by the lubricant. The sliding part gap is lubricated and sealed with an oil film to prevent the high-stage-side discharge gas from flowing into the cylinder through the sliding part gap of the high-stage (final stage) vane 15 and to improve the compression efficiency. Since the stage (final stage) discharge-side lubricating oil can be recovered in the sealed container 1 without circulating through the refrigeration cycle piping system connected to the outside of the compressor, the amount of lubricating oil discharged into the refrigeration cycle is reduced, and the refrigeration cycle efficiency Can be improved.
[0083]
The invention according to claim 2 is configured such that the high stage (final stage) back chamber also serves as an oil reservoir for the high stage (final stage) discharge chamber of the high stage (final stage) compression element. According to this configuration, the lubricating oil separated from the refrigerant discharged in the high-stage (final stage) discharge chamber can be recovered in the sealed container via the high-stage (final stage) back chamber, so that the high stage (final stage) Lubricating oil discharged to the outside of the compressor without being separated from the discharged refrigerant in the discharge chamber can also be recovered in the sealed container again after being separated by a simple oil separating means.
[0084]
According to a third aspect of the present invention, the oil return passage is configured to pass through a bearing sliding portion that supports the drive shaft. And according to this configuration, the lubricating oil in the back chamber of the higher stage (final stage) lubricates the bearing sliding portion of the drive shaft, and is finally collected in the sealed container, so that it surrounds the outer periphery of the compression mechanism. The sealing surface between the parts constituting the compression mechanism is sealed by the lubricating oil film to prevent the gas in the sealed container from flowing into the cylinder of the low-stage (first stage) compression element, thereby improving the compression efficiency. Can do.
[0085]
In the invention according to claim 4, the compression mechanism is a two-stage compression mechanism including a high-stage compression element and a low-stage compression element, and the oil return passage is disposed between the high-stage compression element and the low-stage compression element. It is provided so as to pass through the intermediate plate and the inside of the piston of each compression element sequentially. According to this configuration, the lubricating oil in the back chamber of the high stage (final stage) can be sequentially supplied to the high stage (final stage) vane, the inside of the piston of each compression element, and the bearing sliding portion that supports the drive shaft. The amount of lubricating oil can be ensured by forming an efficient oil supply passage, and the compression efficiency and durability can be improved by the combined effect of oil film sealing of the compression chamber gap and sliding portion lubrication.
[0086]
In the invention described in claim 5, the oil return passage is configured to pass through a middle plate disposed between the final stage compression element and the first stage compression element, and the throttle passage of the oil return passage is provided in the middle plate. It is. According to this configuration, since the oil supply passage having the appropriate length of the throttle passage from the high-stage (final stage) back chamber to the drive shaft is routed, it is possible to continuously supply lubricating oil with a stable throttle effect. Further, it is possible to improve durability by continuously forming the oil film of the sliding portion.
[0087]
The invention according to claim 6 includes a main bearing in which the bearing supporting the drive shaft is disposed at least on the side close to the electric motor, and more than half of the lubricating oil flowing into the sealed container through the oil return passage is formed. The bearing clearance of the main bearing is set so as to pass through the sliding portion of the main bearing. According to this configuration, even when the magnetic attraction force of the electric motor acts on the drive shaft and an excessive load acts on the main bearing, the main oil is supplied by more than half of the lubricating oil returned to the sealed container. A sufficient oil film can be formed on the sliding surface of the bearing, and the durability of the main bearing can be improved.
[0088]
According to the seventh aspect of the present invention, the bearing gap is set so that the inner space of each piston corresponds to the pressure in the final stage discharge chamber. According to this configuration, the refrigerant gas in the cylinder of each compression element is prevented from leaking into the inner space of each piston, so the gas to the bearing sliding surface of the main bearing that supports the drive shaft It is possible to prevent the biting and form a good bearing oil film, thereby further improving the bearing durability.
[0089]
The invention according to claim 8 comprises a main bearing in which a bearing supporting the drive shaft is disposed at least on the side close to the electric motor and a sub-bearing disposed on the side far from the electric motor, and a sealed container through an oil return passage. An oil return passage is configured so that most of the lubricating oil flowing in passes through the sliding portions of the main bearing and the sub-bearing. According to this configuration, the lubricating oil collected on the discharge side of the high-stage (final stage) compression element and returned to the sealed container can be effectively used for oil supply to the bearing sliding surface, and the bearing durability is improved. be able to.
[0090]
According to the ninth aspect of the present invention, the oil return passage is configured to pass through the side surface of the piston that is in sliding contact with the intermediate plate. According to this configuration, the lubricating oil from the back chamber of the upper stage (final stage) seals the sliding side surface gap between the middle plate and the piston with an oil film, and the refrigerant gas in the cylinder during the compression leaks to the inside of the piston. It can prevent and improve the compression efficiency.
[0091]
According to a tenth aspect of the present invention, the oil return passage is provided with a piston sliding contact opening provided in the intermediate plate at a position that does not communicate with the inside of the cylinder of the compression element and faces the side surface of the piston. . According to this configuration, the lubricating oil lubricates the sliding contact side surface of the intermediate plate and the piston, and the throttle passage for reducing the pressure of the lubricating oil passing through the sliding contact side surface is formed by simple means, and the differential pressure oil supply passage is reduced. It can be realized at a cost.
[0092]
According to the eleventh aspect of the present invention, the piston sliding contact opening provided in the intermediate plate is disposed at a position so as to be intermittently opened and closed by the piston. According to this configuration, as the rotational speed of the piston increases, the oil supply passage resistance is adjusted to increase the passage resistance of the lubricating oil that passes from the oil passage in the intermediate plate toward the inside of the piston. It is possible to adjust the amount of lubricating oil flowing out from the back chamber into the sealed container. Thereby, even when the refrigerant speed is high and the separation effect of the lubricating oil is reduced as in the case of high speed operation of the compressor, the lubricating oil in the high stage back chamber can be secured and the lubricating oil can be continuously supplied.
[0093]
The invention according to claim 12 is provided with an axial through oil hole opened on both side surfaces of the piston, and the axial through oil hole is arranged to communicate intermittently with a sliding contact opening provided in the intermediate plate. It is. And according to this configuration, the lubricating oil that has passed through the inside of the intermediate plate is also supplied to the side surface of the piston that is not in sliding contact with the intermediate plate, and an oil film is formed on both side surfaces of the piston. It is possible to prevent leakage to the inside of the piston, improve the compression efficiency, and improve the durability of the piston and the parts in sliding contact with the piston.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view and a connection diagram of a discharge piping system of a rolling piston type rotary two-stage compressor according to a first embodiment of the present invention.
FIG. 2 is a partial sectional view of a compression mechanism section in the compressor.
3 is a cross-sectional view taken along line AA in FIG.
FIG. 4 is a partial longitudinal sectional view of a rolling piston type rotary two-stage compressor showing a second embodiment of the present invention.
FIG. 5 is a cross-sectional view taken along line BB in FIG.
FIG. 6 is a partial longitudinal sectional view of a rolling piston type rotary two-stage compressor showing a third embodiment of the present invention.
FIG. 7 is a partial detail view of the compression mechanism.
FIG. 8 is an external view of the piston of the compression mechanism.
FIG. 9 is a partial longitudinal sectional view of a rolling piston type rotary two-stage compressor showing a fourth embodiment of the present invention.
FIG. 10 is a longitudinal sectional view of a conventional rolling piston type rotary two-stage compressor.
FIG. 11 is a cross-sectional view taken along the line CC of the compressor.
FIG. 12 is a partial sectional view of another conventional rolling piston type rotary two-stage compressor.
[Explanation of symbols]
1 Airtight container
2 Electric motor
3 Two-stage compression mechanism
4 High stage (final stage) compression element
5 Low stage (first stage) compression element
7 Drive shaft
9 Main bearing
11 Secondary bearing
13 High (final) discharge chamber
14 Oil sump
15 High (final) vanes
16 High (last stage) back room
65 piston
68 Oil return passage
68b Restricted passage
70 piston
99 Oil separator
204 High-stage (final stage) compression element
205 Low stage (first stage) compression element
206 Middle plate
206a Restricted passage
207 Drive shaft
213 High (final) discharge chamber
214 Oil sump
216 High (last stage) back room
232 Oil sump
265 High (last) piston
265a Axial through oil hole
270 Low stage (first stage) piston
270a Axial through oil hole

Claims (12)

  1. 密閉容器内に、複数の圧縮要素を順次直列接続した多段圧縮機構と前記多段圧縮機構の駆動軸に連結する電動機とを収納し、前記圧縮要素の各シリンダ内を出没しつつ吸入室と圧縮室とに区画する各ベーンのうち、高段圧縮要素の高段ベーンの高段背面室が前記高段圧縮要素の吐出側に連通する一方、低段圧縮要素の吐出側が前記密閉容器内に連通した構成において、前記高段圧縮要素の吐出側で気体から分離した潤滑油を、前記高段背面室を経由して前記密閉容器内に戻す絞り通路を有した油戻し通路を備えたロータリ式多段圧縮機。In a sealed container, a multistage compression mechanism in which a plurality of compression elements are sequentially connected in series and an electric motor connected to a drive shaft of the multistage compression mechanism are housed, and a suction chamber and a compression chamber are projected and retracted inside each cylinder of the compression element. Among the vanes divided into the upper stage, the high stage back chamber of the high stage vane of the high stage compression element communicates with the discharge side of the high stage compression element, while the discharge side of the low stage compression element communicates with the inside of the sealed container. In the configuration, rotary multistage compression provided with an oil return passage having a throttle passage for returning the lubricating oil separated from the gas on the discharge side of the high stage compression element into the sealed container via the high stage back chamber. Machine.
  2. 高段背面室が高段圧縮要素の高段吐出室の油溜を兼ねるべく構成された請求項1記載のロータリ式多段圧縮機。The rotary multistage compressor according to claim 1, wherein the high stage back chamber is configured to serve as an oil reservoir for the high stage discharge chamber of the high stage compression element.
  3. 油戻し通路は、駆動軸を支持する軸受摺動部を経由すべく構成された請求項1または請求項2記載のロータリ式多段圧縮機。The rotary multistage compressor according to claim 1 or 2, wherein the oil return passage is configured to pass through a bearing sliding portion that supports the drive shaft.
  4. 圧縮機構を高段圧縮要素と低段圧縮要素から成る2段圧縮機構とし、その油戻し通路は、高段圧縮要素と低段圧縮要素との間に配置した中板と、各圧縮要素のピストンの内側とを順次経由すべく設けられた請求項3記載のロータリ式多段圧縮機。The compression mechanism is a two-stage compression mechanism composed of a high-stage compression element and a low-stage compression element, and the oil return passage has an intermediate plate disposed between the high-stage compression element and the low-stage compression element, and a piston for each compression element The rotary multistage compressor according to claim 3, wherein the rotary multistage compressor is provided so as to sequentially pass through the inside of the compressor.
  5. 油戻し通路は、高段圧縮要素と低段圧縮要素との間に配置した中板を経由すべく構成し、絞り通路を中板に設けた請求項3記載のロータリ式多段圧縮機。4. The rotary multistage compressor according to claim 3, wherein the oil return passage is configured to pass through a middle plate disposed between the high-stage compression element and the low-stage compression element, and a throttle passage is provided in the middle plate.
  6. 駆動軸を支持する軸受は少なくとも電動機に近い側に配置された主軸受を含み、油戻し通路を介して密閉容器内に流入する潤滑油の内の半分以上が前記主軸受の摺動部を通過すべく前記主軸受の軸受隙間を設定した請求項3記載のロータリ式多段圧縮機。The bearing that supports the drive shaft includes at least a main bearing disposed on the side close to the electric motor, and more than half of the lubricating oil flowing into the sealed container through the oil return passage passes through the sliding portion of the main bearing. The rotary multistage compressor according to claim 3, wherein a bearing clearance of the main bearing is set.
  7. 各ピストンの内側空間が最終段吐出室の圧力相当になるように軸受隙間を設定した請求項6記載のロータリ式多段圧縮機。The rotary multistage compressor according to claim 6, wherein the bearing clearance is set so that the inner space of each piston corresponds to the pressure of the final stage discharge chamber.
  8. 駆動軸を支持する軸受は少なくとも電動機に近い側に配置された主軸受と前記電動機に遠い側に配置された副軸受とから成り、油戻し通路を介して密閉容器内に流入する潤滑油の内の大部分が前記主軸受と前記副軸受の摺動部を通過すべく前記油戻し通路を構成した請求項3記載のロータリ式多段圧縮機。The bearing that supports the drive shaft is composed of at least a main bearing disposed on the side close to the electric motor and a secondary bearing disposed on the side far from the electric motor. Of the lubricating oil flowing into the sealed container through the oil return passage, The rotary multistage compressor according to claim 3, wherein the oil return passage is configured so that most of the oil passes through sliding portions of the main bearing and the auxiliary bearing.
  9. 油戻し通路は、中板と摺接するピストンの側面を経由すべく構成された請求項4記載のロータリ式多段圧縮機。5. The rotary multistage compressor according to claim 4, wherein the oil return passage is configured to pass through a side surface of the piston that is in sliding contact with the intermediate plate.
  10. 油戻し通路は、中板に設けられたピストン摺接開口部が、圧縮要素のシリンダ内と連通せず且つピストンの側面と対向する位置に設けられた請求項9記載のロータリ式多段圧縮機。10. The rotary multistage compressor according to claim 9, wherein the oil return passage is provided at a position where a piston sliding contact opening provided in the intermediate plate does not communicate with the inside of the cylinder of the compression element and faces the side surface of the piston.
  11. 中板に設けられたピストン摺接開口部が、前記ピストンによって間欠的に開閉されるべく位置に配置された請求項10記載のロータリ式多段圧縮機。The rotary multistage compressor according to claim 10, wherein a piston sliding contact opening provided in the intermediate plate is disposed at a position to be opened and closed intermittently by the piston.
  12. ピストンの両側面に開通する軸方向貫通油穴を設け、前記軸方向貫通油穴は中板に設けた摺接開口部と間欠的に連通すべく配置された請求項11記載のロータリ式多段圧縮機。The rotary multistage compression according to claim 11, wherein axial through oil holes are provided on both side surfaces of the piston, and the axial through oil holes are disposed so as to intermittently communicate with sliding contact openings provided in the intermediate plate. Machine.
JP2001109623A 2001-04-09 2001-04-09 Rotary multistage compressor Expired - Lifetime JP4258132B2 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103415705A (en) * 2011-02-28 2013-11-27 三洋电机株式会社 Multistage-compression rotary compressor and compression rotary compressor

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EP2180189A3 (en) * 2003-09-30 2010-08-25 Sanyo Electric Co., Ltd. Horizontal type rotary compressor
JP4174766B2 (en) * 2003-10-06 2008-11-05 三菱電機株式会社 Refrigerant compressor
TW200619505A (en) * 2004-12-13 2006-06-16 Sanyo Electric Co Multicylindrical rotary compressor, compression system, and freezing device using the compression system
KR20070074300A (en) * 2006-01-09 2007-07-12 삼성전자주식회사 Rotary compressor
JP5218596B2 (en) * 2011-05-12 2013-06-26 三菱電機株式会社 Rotary compressor
CN103953544B (en) * 2014-04-10 2016-01-27 珠海格力节能环保制冷技术研究中心有限公司 Compressor and air conditioner
CN104061165A (en) * 2014-07-15 2014-09-24 珠海凌达压缩机有限公司 Rotary compressor and spring fixing structure thereof

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103415705A (en) * 2011-02-28 2013-11-27 三洋电机株式会社 Multistage-compression rotary compressor and compression rotary compressor
CN103415705B (en) * 2011-02-28 2016-01-13 三洋电机株式会社 Multiple compression rotary compressor and compression type rotary compressor

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