JPH1113661A - Screw compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a performance by arranging a lip in a radial direction from an outer diameter of a screw rotor on a suction end surface outer peripheral part of the screw rotor, in a suction port capable of sucking air from an axial direction, and not having an opening part for sucking air from a radial direction. SOLUTION: Oil oiled from a compressing stroke side is passed an engaging clearance of a rotor, and injected into a suction port 4. Oil mist is formed by means of high speed rotation, and is advanced into a suction chamber by passing a leaking passage 7 along a bore inner diameter by centrifugal force. As a result, the oil mist having a high temperature is heat-exchanged with air which is sucked from one to another, a suction air temperature is raised, and a volume efficiency is reduced since thermal expansion is carried out. A wall 8 for preventing heating of intake air is arranged, a clearance 9 between the wall 8 and a suction side end surface is formed in a small size so as to prevent formation of a leakage passage which is new continuously to a leakage passage 7, and thereby, oil mist leaked along a bore inner wall is prevented. It is thus possible to prevent intake air heating, and it is also possible to hold a high volume efficiency.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は油冷式のスクリュー
圧縮機に係り、特に高い効率を実現するに好適な構造に
関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil-cooled screw compressor, and more particularly to a structure suitable for realizing high efficiency.

【０００２】[0002]

【従来の技術】作動室内に注入した油の逆流が吸込み室
内にオイルミストとなって浮遊し、吸入途中の吸込み空
気を加熱し、いわゆる吸気加熱を起こす。吸気加熱はオ
イルミストによらずとも、配管表面との熱交換などから
もわずかには起こるものの、オイルミストは表面積が極
めて大きく吸気加熱の主因をなす。吸気加熱は被圧縮気
体の温度を上昇させ体積を膨張させるために、一定体積
の気体を吸入する容積型圧縮機においては吸入質量の減
少をもたらし、体積効率を低下させる。2. Description of the Related Art The reverse flow of oil injected into a working chamber floats as an oil mist in a suction chamber and heats suction air in the course of suction to cause so-called suction heating. Although the intake air heating does not depend on the oil mist but slightly occurs due to heat exchange with the pipe surface, the oil mist has an extremely large surface area and is a main cause of the intake air heating. Inlet heating increases the temperature of the gas to be compressed and expands the volume, so that in a positive displacement compressor that sucks a constant volume of gas, the intake mass is reduced and the volume efficiency is reduced.

【０００３】オイルミストの発生要因について詳述す
る。作動室に注入した油が圧縮された空気の作動室間の
すきまからの漏れに添って逆流し、吸入室に吹き出すた
めである。スクリューロータは高速回転しているので、
スクリューロータとともに回転している作動室から吸入
室へ吹き出した油は飛散し霧状になりやすい。[0003] The cause of oil mist generation will be described in detail. This is because the oil injected into the working chamber flows backward along with leakage of the compressed air from the gap between the working chambers and blows out to the suction chamber. Since the screw rotor is rotating at high speed,
Oil blown from the working chamber rotating together with the screw rotor to the suction chamber is liable to be scattered and become mist.

【０００４】このオイルミスト低減策として、特許公告
昭42−10027 号公報に一例が示されている。その方法は
吸込みポート内のオイルミストが吸込み端面側へ漏れる
ことを防ぐために、吸込み端面からロータ外周側にリッ
プ部（本公知例では唇部と記載）を設置している。この
方法は吸込みポート内からの漏れについては言及してい
るものの、ボア内面に沿った漏れ防止については言及し
ていない。[0004] An example of this oil mist reduction measure is disclosed in Japanese Patent Publication No. 42-10027. In this method, a lip (referred to as a lip in this known example) is provided from the suction end face to the outer peripheral side of the rotor in order to prevent oil mist in the suction port from leaking to the suction end face side. Although this method mentions leakage from inside the suction port, it does not mention leakage prevention along the bore inner surface.

【０００５】[0005]

【発明が解決しようとする課題】吸気加熱を防止する方
法は、吸い込み直前の空気とオイルミストの熱交換を抑
制すればよく、吸入室内部のオイルミストを減らすか、
オイルミストの温度を低くすることが考えられる。オイ
ルミストの温度を低くするには注入する油温度を低下さ
せる方法があるが、あまり低温にすると十分な温度まで
吐出温度を上げられなくなるためドレン発生の懸念があ
り限度がある。A method for preventing the intake air from heating is to suppress the heat exchange between the air and the oil mist immediately before the suction, and to reduce the oil mist inside the suction chamber or
It is conceivable to lower the temperature of the oil mist. In order to lower the temperature of the oil mist, there is a method of lowering the temperature of the oil to be injected.

【０００６】上記問題点を含み、本発明は吸気加熱対策
として吸い込み直前の空気とオイルミストの熱交換を抑
制し、圧縮機性能を向上させるスクリュー圧縮機を実現
させることを目的とする。[0006] In view of the above problems, an object of the present invention is to realize a screw compressor that suppresses heat exchange between air and oil mist immediately before suction and improves compressor performance as a measure against intake air heating.

【０００７】[0007]

【課題を解決するための手段】上記目的を達成させるた
めに以下の手段を用いる。To achieve the above object, the following means are used.

【０００８】空気を軸方向から吸込み、径方向からは吸
込む開口部がない吸込みポートにおいて、吸込み室への
油飛散防止用に、スクリューロータの吸込み端面の外周
部にロータ外径より半径方向へリップを設置する。At the suction port which sucks air from the axial direction and has no opening for suction from the radial direction, a lip is formed radially from the outer diameter of the rotor outer diameter on the outer peripheral portion of the suction end face of the screw rotor to prevent oil from scattering into the suction chamber. Is installed.

【０００９】[0009]

【発明の実施の形態】以下、図１，図２を用いて、本発
明の実施の形態である油冷式スクリュー空気圧縮機の構
成と動作を説明する。雄スクリューのロータ１と雌スク
リューのロータ２は噛み合って、ケーシング３内部に形
成された円筒状ボア空間に収納される。尚、雄と雌のス
クリューロータを総称してスクリューロータと呼び、ま
た、省略して単にロータと記す。図２のように吸込み側
の両ロータの半径方向に設けられている空間が吸込みポ
ート４であり、吸込み側端面から作動室側に取り付けた
唇部をリップ５と定義し、また、吸込みポート４と吸込
み室６をつなぐ、ロータ外径とリップ内径との隙間をオ
イルミストの漏れ通路７と定義する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction and operation of an oil-cooled screw air compressor according to an embodiment of the present invention will be described below with reference to FIGS. The male screw rotor 1 and the female screw rotor 2 mesh with each other and are housed in a cylindrical bore space formed inside the casing 3. The male and female screw rotors are collectively referred to as a screw rotor, and abbreviated to simply referred to as a rotor. As shown in FIG. 2, the space provided in the radial direction of both rotors on the suction side is a suction port 4, and a lip attached from the suction side end face to the working chamber side is defined as a lip 5. A gap between the outer diameter of the rotor and the inner diameter of the lip, which connects the suction chamber 6 and the suction chamber 6, is defined as a leakage passage 7 for oil mist.

【００１０】吸気加熱に影響を及ぼす油の流れと、オイ
ルミストの形成について以下に説明する。圧縮工程側か
ら給油された油は、ロータの噛合い隙間を通り、吸込み
ポート４内に噴射される。この時噴射される油はロータ
の高速回転に伴って噴射されるので飛散し、オイルミス
トを形成する。さらに、この吸込みポート４内のオイル
ミストは遠心力によりボア内径に沿って漏れ通路７を通
り、吸込み室内に進入する。その結果、この高温のオイ
ルミストが、次々と吸込まれてくる空気と熱交換するた
めに、吸込み空気温度が上昇して熱膨張するため体積効
率の低下に至る。この吸気加熱低減策として、過去の特
許にリップ５を取り付けるというものがあるが、このリ
ップ５を取り付けただけでは漏れ通路７により、吸込み
ポート４から吸込み室６への漏れが発生してしまう。[0010] The flow of oil affecting the intake air heating and the formation of oil mist will be described below. The oil supplied from the compression step side is injected into the suction port 4 through the meshing gap of the rotor. The oil injected at this time is scattered because it is injected with the high-speed rotation of the rotor, and forms oil mist. Further, the oil mist in the suction port 4 passes through the leak passage 7 along the bore diameter by centrifugal force and enters the suction chamber. As a result, since the high-temperature oil mist exchanges heat with the air being sucked one after another, the temperature of the sucked air rises and thermally expands, resulting in a decrease in volumetric efficiency. As a measure for reducing the intake air heating, there is a past patent in which a lip 5 is attached. However, if only the lip 5 is attached, leakage from the intake port 4 to the intake chamber 6 occurs due to the leakage passage 7.

【００１１】そこで本発明では吸気加熱防止用壁８を設
置すれば、ボア内面に沿って漏れてくるオイルミストを
多少防ぐことが出来るので、体積効率の上昇が考えられ
る。また、この吸気加熱防止用壁８と吸込み側端面との
隙間９が、漏れ通路７に続く新たな漏れ通路とならぬよ
うに隙間９は小さく設定しなくてはならない。Therefore, in the present invention, if the intake air heating prevention wall 8 is provided, the oil mist leaking along the inner surface of the bore can be prevented to some extent, so that the volume efficiency can be increased. In addition, the gap 9 must be set small so that the gap 9 between the intake heating prevention wall 8 and the suction-side end face does not become a new leak passage following the leak passage 7.

【００１２】[0012]

【発明の効果】本発明により、吸気加熱を防止し高い体
積効率を保つ油冷式スクリュー圧縮機を実現することが
できる。According to the present invention, it is possible to realize an oil-cooled screw compressor that prevents intake air heating and maintains high volumetric efficiency.

【図面の簡単な説明】[Brief description of the drawings]

【図１】本発明の実施の形態における油冷式スクリュー
圧縮機の吸込み側端面から見た内部構造図である。FIG. 1 is an internal structural view of an oil-cooled screw compressor according to an embodiment of the present invention as viewed from a suction-side end face.

【図２】本発明の実施の形態における油冷式スクリュー
圧縮機の軸平行での切断面図である。FIG. 2 is a cross-sectional view of the oil-cooled screw compressor according to the embodiment of the present invention, taken in a direction parallel to the axis.

【符号の説明】[Explanation of symbols]

１…雄ロータ、２…雌ロータ、３…主ケーシング、４…
吸込みポート、５…リップ、６…吸込み室、７…漏れ通
路、８…吸気加熱防止用壁、９…隙間。1. Male rotor, 2. Female rotor, 3. Main casing, 4.
Suction port, 5: lip, 6: suction chamber, 7: leakage passage, 8: wall for preventing intake heat, 9: gap.

───────────────────────────────────────────────────── フロントページの続き (72)発明者 青木 優和 静岡県清水市村松390番地 株式会社日立 製作所空調システム事業部内 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yuka Aoki 390 Muramatsu, Shimizu-shi, Shizuoka Prefecture Air Conditioning Systems Division, Hitachi, Ltd.

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】雌雄２つのスクリューロータと、それらを
収納するボアを内部に形成したケーシングと該２つのス
クリューロータの両端をそれぞれ軸支する軸受を備え、
該２つのスクリューロータが互いに噛み合いながら回転
することにより被圧縮気体を吸入，圧縮，吐出する機能
を有する圧縮機本体に、作動室内に吸入し閉じ込めた空
気に油を注入しうる機能を備えた油冷式スクリュー圧縮
機において、空気を作動室内へ軸方向導入する吸入ポー
トが設けられ、径方向から導入する開口部がなく、リッ
プ部がスクリューロータの吸入側端面の外周部に面し設
置され、前記リップ部がロータ外径より半径方向内側へ
延びていることを特徴としたスクリュー圧縮機。1. A vehicle comprising two male and female screw rotors, a casing formed therein with a bore for accommodating them, and bearings for axially supporting both ends of the two screw rotors, respectively.
An oil having a function of injecting oil into the air sucked and trapped in the working chamber into a compressor body having a function of sucking, compressing, and discharging the compressed gas by rotating the two screw rotors while meshing with each other; In the cold screw compressor, a suction port for introducing air into the working chamber in the axial direction is provided, there is no opening for introducing the air from the radial direction, and a lip portion is installed facing the outer peripheral portion of the suction side end face of the screw rotor, The screw compressor wherein the lip portion extends radially inward from the outer diameter of the rotor.