JP3555702B2 - Scroll type compressor and manufacturing method thereof - Google Patents

Description

【００３１】
そして、その圧縮室を形成する可動渦巻体１の内壁面にある点を仮定し、単位ベクトルを数２のように定義すれば、その点に作用する力は、その圧縮室の内面積をＳとすることにより、数３で表される。
【００３２】
【数２】

【００３３】
【数３】

【００３４】
このため、圧縮反力によるモーメントＭｐは数４により表される。
【００３５】
【数４】

【００３６】
この圧縮反力によるモーメントＭｐの大きさＭ（Ｎ・ｍ）と駆動軸の回転角Φ（°）との関係を図３のグラフに示す。上記公報記載の技術のようにクランク中心軸線Ｐと、可動スクロール全体の重心Ｇとを軸方向で一致させたスクロール型圧縮機では、かかる圧縮反力の大きな振幅により動力損失及び異音を生じやすかったのである。
【００３７】
また、遠心力によるクランク中心軸線Ｐ周りのモーメントＭｃの大きさ（Ｎ・ｍ）と駆動軸の回転角Φ（°）との関係を求める。この遠心力による関係は図１に示す仮重心Ｇ_０ により決定されるため、以下のように求められる。
すなわち、このスクロール型圧縮機では、図２の（Ｘ，Ｙ）直交座標に示すように、駆動軸の回転によりクランク中心軸線Ｐに駆動力Ｆが作用すれば、トルクＦ・Ｒにより可動スクロールが公転駆動される。このとき、遠心力Ｃ_１ 、Ｃ_２ …は仮重心Ｇ_０ において駆動中心軸線Ｏから遠心方向に作用するが、このスクロール型圧縮機では、仮重心Ｇ_０ がクランク中心軸線Ｐと一致していない。このため、仮重心Ｇ_０ と駆動中心軸線Ｏとの距離Ｒ_１ 、Ｒ_２ …は回転角Φ（°）の変化に応じて正弦的に変化し、遠心力Ｃ_１ 、Ｃ_２ …は距離Ｒ_１ 、Ｒ_２ …に応じて正弦的に変化する。このため、図４に示すように、クランク中心軸線Ｐを原点とする（Ｘ’，Ｙ’）直交座標に遠心力Ｃ_１ 、Ｃ_２ …のベクトルを拡大して写像すれば、遠心力Ｃ_１ 、Ｃ_２ …によるモーメントＭｃがクランク中心軸線Ｐ周りに生じ、遠心力Ｃ_１ 、Ｃ_２ …によるモーメントＭｃは回転角Φ（°）に応じて正弦的に変化することがわかる。
【００３８】
したがって、遠心力によるモーメントＭｃは、振幅をａ’、位相差をφ’、定数をｂ’とすれば、数５により表される。
【００３９】
【数５】

【００４０】
「第３工程」
そして、圧縮反力によるモーメントＭｐと遠心力によるモーメントＭｃとの回転角Φ（°）毎の合計を求めれば、これが自転モーメントＭｍである。
次いで、自転モーメントＭｍの振幅が最少値になるようにモーメントＭｃの振幅ａ’、位相差φ’及び定数ｂ’を変更する。変更後の振幅をａ、位相差をφ、定数をｂ、真の重心Ｇの図１の（ｘ，ｙ）直交座標上の位置を（ｘ_Ｇ ，ｙ_Ｇ ）、可動スクロールの質量をｍとし、駆動軸の角速度をωとすれば、図１を拡大して示す図５から数６、数７が成立する。
【００４１】
【数６】

【００４２】
【数７】

【００４３】
そして、求めた座標（ｘ_Ｇ ，ｙ_Ｇ ）上に可動スクロール３全体の真の重心Ｇがくるように可動側板２の裏面に肉盛又は肉盗みを行なう。図１に真の重心Ｇを示す。
こうして得られたスクロール型圧縮機では、可動スクロール３全体の真の重心Ｇの設定により、クランク中心軸線Ｐ周りに遠心力によるモーメントＭｃを生じる。そして、圧縮反力によるモーメントＭｐにより可動スクロール３がクランク中心軸線Ｐを中心として自転しようとしても、この遠心力によるモーメントＭｃがその圧縮反力によるモーメントＭｐを可及的に相殺するため、可動スクロール３はクランク中心軸線Ｐを中心として自転しにくくなっている。
【００４４】
すなわち、このスクロール型圧縮機では、図３に示すように、自転モーメントＭｍは圧縮反力によるモーメントＭｐよりもΔＭだけ振幅が小さくなっている。このため、このスクロール型圧縮機では、圧縮室を区画している接触線のうちの２箇所は離反しにくく、圧縮室のシール性が確保され、流体漏れを生じにくい。また、圧縮反力によるモーメントＭｐを支持する支持点は移動しにくい。
【００４５】
したがって、このスクロール型圧縮機は、高速回転、高圧縮比等により圧縮反力によるモーメントＭｐが大きくなった場合でも、動力損失及び異音を生じにくいものである。
（実施例２）
実施例２では請求項２、３、５を具体化している。
【００４６】
「第１工程」
まず、実施例１と同様、図１及び図２に示すように、可動スクロール３における可動渦巻体１の形状と、可動側板２の形状と、可動側板２上の可動渦巻体１の位置とを仮設定する。
また、駆動軸の駆動中心軸線Ｏと、可動スクロール３を駆動するクランクピンのクランク中心軸線Ｐとを設定する。
【００４７】
「第２工程」
次に、実施例１と同様、固定渦巻体の形状と可動渦巻体１の形状とにより決定される圧縮反力によるモーメントＭｐの大きさＭ（Ｎ・ｍ）と駆動軸の回転角Φ（°）との関係を求める。この圧縮反力によるモーメントＭｐを図６に示す。
「第３工程」
この後、数８のｆ（ｘ）にモーメントＭｐを代入することにより、モーメントＭｐをフーリエ変換する。
【００４８】
【数８】

【００４９】
フーリエ級数の１０次成分までの係数を図７に示す。
圧縮反力によるモーメントＭｐの周期は２π（ｒａｄ）つまり１８０（°）であり、また遠心力によるモーメントＭｃの周期も同じく２π（ｒａｄ）つまり１８０（°）となる。このため、圧縮反力によるモーメントＭｐのうち回転角の１次成分を打ち消すことがモーメントＭｐを低減するのに有効である。このことは、図７に示すように、２次成分以降の係数が小さいことにも裏付けされている。
【００５０】
よって、圧縮反力によるモーメントＭｐをフーリエ展開した１次成分Ｍｐ’は数９で与えられる。
【００５１】
【数９】

【００５２】
ここで、ａ’は振幅、φ’は位相差、ｂ’は定数を示す。
そして、数９の振幅ａ’を−ａ’とし、数１０のように、モーメントＭｐ’を完全に打ち消す遠心力によるモーメントＭｃを算出する。
【００５３】
【数１０】

【００５４】
実施例２の可動渦巻体１の形状により得られた圧縮反力によるモーメントＭｐをフーリエ展開した１次成分Ｍｐ’は数１１であった。
【００５５】
【数１１】

【００５６】
次いで、可動スクロール１の真の重心Ｇが数１０の遠心力関係をもつべく可動側板２に肉盛又は肉盗みを行なう。
なお、可動スクロール３全体の真の重心Ｇ（ｘ_Ｇ ，ｙ_Ｇ ）は数１２、数１３を満たす。ここで、可動スクロールの質量はｍ、駆動軸の角速度はωである。
【００５７】
【数１２】

【００５８】
【数１３】

【００５９】
こうして得られたスクロール型圧縮機では、図８に示すように、自転モーメントＭｍは真の重心ＧによるモーメントＭｃにより打ち消された結果、圧縮反力によるモーメントＭｐよりも振幅が小さくなっている。このため、このスクロール型圧縮機においても、実施例１と同様の作用及び効果を奏することができる。
（実施例３）
実施例３では、インボリュート曲線よりも伸開角θの増加に応じて徐々に減衰する曲線で可動渦巻体１及び固定渦巻体の形状を決定している。他の構成は実施例１と同一である。
【００６０】
すなわち、図９に示す（ｘ，ｙ）直交座標の原点に渦巻き中心Ｑを設定し、この渦巻き中心Ｑに半径Ａの図示しない基礎円を仮定する。そして、基礎円上の点からの距離をｒ、伸開角をθ、正の定数をＢ、２以上の次数をｎとし、（ｘ，ｙ）直交座標と一致させた（ｒ，θ）極座標の横軸ｘ上にある基礎円上の始点から
ｒ＝Ａ・θ−Ｂθ^ｎ
の第１の曲線を最終伸開角まで描く。次いで、この第１の曲線から公転半径Ｒ分外方に離れた第２の曲線を描く。また、第２の曲線を渦巻き中心Ｑと対称位置に反転させることにより、第３の曲線を描く。そして、第１の曲線上の始点と第３の曲線上の始点とを円弧及び直線により滑らかに接続するとともに、第１の曲線上の終点を法線により第３の曲線に接続し、可動渦巻体１の形状を決定する。
【００６１】
こうして決定された可動渦巻体１の形状等では、真の重心Ｇは図９に示す位置とすべきことが明らかとなった。このスクロール型圧縮機においても、実施例１と同様の作用及び効果を奏することができる。
（実施例４）
実施例４では、アルキメデス曲線で可動渦巻体１及び固定渦巻体の形状を決定している。他の構成は実施例１と同一である。
【００６２】
すなわち、図１０に示す（ｘ，ｙ）直交座標の原点に渦巻き中心Ｑを設定し、この渦巻き中心Ｑから
ｒ＝Ａ・θ
の第１のアルキメデス曲線を最終伸開角まで描く。ここで、Ａは正の定数、ｒは渦巻き中心Ｑからの距離、θは（ｒ，θ）極座標を（ｘ，ｙ）直交座標と一致させた場合の横軸ｘからの伸開角である。次いで、この第１のアルキメデス曲線から公転半径Ｒ分外方に離れた第２のアルキメデス曲線を描く。また、第２のアルキメデス曲線を渦巻き中心Ｑと対称位置に反転させることにより、第３のアルキメデス曲線を描く。そして、第１のアルキメデス曲線上のある点と第３のアルキメデス曲線上のある点とを円弧及び直線により滑らかに接続するとともに、第１のアルキメデス曲線上の終点を法線により第３のアルキメデス曲線に接続し、可動渦巻体１の形状を決定する。
【００６３】
こうして決定された可動渦巻体１の形状等では、真の重心Ｇは図１０に示す位置とすべきことが明らかとなった。このスクロール型圧縮機においても、実施例１と同様の作用及び効果を奏することができる。
【００６４】
【発明の効果】
以上詳述したように、請求項１、２のスクロール型圧縮機は、請求項１、２記載の構成を採用しているため、動力損失及び異音を生じにくいものである。
また、請求項３〜５のスクロール型圧縮機の製造方法を採用すれば、請求項１、２のスクロール型圧縮機を製造することができる。
【図面の簡単な説明】
【図１】実施例１に係り、可動スクロールの平面図である。
【図２】実施例１に係り、駆動軸の駆動中心軸線の位置、クランク中心軸線のの位置等を模式的に示す直交座標である。
【図３】実施例１に係り、モーメントの大きさと駆動軸の回転角との関係を示すグラフである。
【図４】実施例１に係り、クランク中心軸線周りの遠心力を示すベクトル図である。
【図５】実施例１に係り、図１の拡大図である。
【図６】実施例２に係り、圧縮反力によるモーメントの大きさ及びフーリエ級数の１次成分の大きさと、駆動軸の回転角との関係を示すグラフである。
【図７】実施例２に係り、圧縮反力によるモーメントにおいて、大きさと次数との関係を示すグラフである。
【図８】実施例２に係り、圧縮反力によるモーメントの大きさ及び自転モーメントの大きさと、駆動軸の回転角との関係を示すグラフである。
【図９】実施例３に係り、可動スクロールの平面図である。
【図１０】実施例４に係り、可動スクロールの平面図である。
【図１１】従来例に係り、駆動軸の駆動中心軸線の位置、クランク中心軸線のの位置等を模式的に示す直交座標である。
【図１２】一般的なスクロール型圧縮機の固定渦巻体と可動渦巻体とを示す平面図である。
【符号の説明】
３…可動スクロール ２…可動側板 １…可動渦巻体
Ｍｐ…圧縮反力によるモーメント Ｍｃ…遠心力によるモーメント
Ｇ…真の重心 Ｇ_０ …仮重心 Ｏ…駆動中心軸線
Ｒ…公転半径 Ｐ…クランク中心軸線 Φ…回転角
Ｍｍ…自転モーメント ａ、ａ’…振幅 φ、φ’…位相差[0001]
[Industrial applications]
The present invention relates to a scroll compressor and a method for manufacturing the scroll compressor.
[0002]
[Prior art]
The scroll type compressor has a fixed scroll and a movable scroll which is non-rotatably and revolvably supported opposite to the fixed scroll, and a compression chamber formed between the fixed scroll and the movable scroll has a movable scroll. The fluid in the compression chamber is compressed by reducing the volume based on the revolution of. The fixed scroll includes a concentric fixed side plate fixed to the housing, and a fixed spiral body vertically projecting from the fixed side plate and having inner and outer wall surfaces formed in a spiral shape. The movable scroll includes a concentric movable side plate driven by a drive shaft via a crank pin, and a movable scroll body vertically projecting from the movable side plate and having inner and outer wall surfaces formed in a spiral shape. The inner and outer wall surfaces of these two spiral bodies can be formed by an involute curve or the like which sets a certain spiral center and is 180 ° out of phase with each other.
[0003]
Focusing on the fact that the center of the spiral does not always coincide with the center of gravity of the movable spiral body in this scroll type compressor, as shown schematically in (X, Y) orthogonal coordinates in FIG. A certain crank center axis P, a center axis Q of a movable side plate in a movable scroll, and a center of gravity G of a movable scroll.₂Are known in the axial direction (Japanese Patent Publication No. 64-2794).
[0004]
In this scroll type compressor, the crank center axis P is radially separated from the drive center axis O, which is the center axis of the drive shaft, by the revolution radius R. Therefore, the drive force F is applied to the crank center axis P by the rotation of the drive shaft. Works, the orbiting scroll is driven to revolve by the torque FR. During this time, the movable spiral body is prevented from rotating by a rotation preventing mechanism (not shown). At this time, if the movable side plate is simply formed concentrically, the center of gravity G of the movable side plate is placed on the center axis Q of the movable side plate.₁Exists, the center of gravity G of the entire movable scroll is set to the center of gravity G of the movable side plate.₁And the center of gravity G of the movable spiral body₂In the axial direction, and the center axis P of the crank and the center of gravity G of the entire movable scroll coincide in the axial direction.
[0005]
For this reason, in this scroll compressor, the centrifugal force C always acts in the centrifugal direction on the crank center axis P from the drive center axis O, and the unbalance due to the centrifugal force C of the orbiting scroll during rotation is prevented. Is possible.
[0006]
[Problems to be solved by the invention]
However, in the scroll compressor, the volume of the compression chamber formed between the fixed scroll and the movable scroll sequentially decreases based on the revolution of the movable scroll. Acts on the movable scroll through. When the moment due to the compression reaction force is also taken into consideration, in the scroll compressor in which the crank center axis P and the center of gravity G of the entire orbiting scroll are aligned in the axial direction as described above, power loss and abnormal noise are likely to occur. .
[0007]
That is, as shown by (x, y) orthogonal coordinates in FIG. 12, each of the compression chambers 90a to 90e must be closed, so that the movable spiral body 91 and the fixed spiral body 92 have an axial contact line T.₁~ T₆The compression chambers 90a to 90e are partitioned by two of the above. For example, the compression chamber 90a has a contact line T₃, T₅It is divided by. The moment due to the compression reaction force, together with the pressing force F ′ from the crankpin based on the driving force F for pressing the movable spiral body 91 against the fixed spiral body 92, together with the contact line T₁~ T₆Etc. and any two of the plurality of rotation preventing mechanisms (not shown).
[0008]
Here, the contact line T₁~ T₆In consideration of the manufacturing tolerance and the fact that the compression chambers 90a to 90e are increased in pressure toward the inner peripheral side, the innermost contact line T₁, T₂Is reliably formed, and the contact line T on the outer peripheral side is formed.₃It can be made to have a slightly smaller gap. In this case, if the moment due to the compression reaction force is not so large due to low-speed rotation, low compression ratio, etc., first, the contact line T on the innermost peripheral side₁, T₂Supported by
[0009]
However, in the above-mentioned conventional scroll type compressor, the centrifugal force C is always acting on the crank center axis P in the centrifugal direction from the drive center axis O, and a force for reducing the moment of the compression reaction force is generated. When the moment due to the compression reaction force increases due to high-speed rotation, high compression ratio, or the like, the movable scroll will rotate, albeit minute, due to the inevitable gap of the rotation preventing mechanism. Such rotation of the orbiting scroll occurs around the crank center axis P. For example, if a boss is provided on the movable side plate and this boss is supported on the crankpin side via a needle bearing, the movable scroll rotates around the center axis of the boss that coincides with the crank center axis P. I do.
[0010]
For this reason, the contact line T partitioning the compression chambers 90a to 90e.₁~ T₆And the like are separated from each other, albeit minutely, and the sealing performance of the compression chambers 90a to 90e is reduced. Thus, fluid leakage occurs and power loss occurs.
In this case, the contact line T on the innermost peripheral side that supported the moment due to the compression reaction force.₁, T₂Are separated, and the contact line T on the outer peripheral side₃Since the moment due to the compression reaction force is supported at any two positions among the plural positions of the rotation preventing mechanism and the like, abnormal noise occurs when the support point moves.
[0011]
An object of the present invention is to solve the problem of making it difficult for power loss and abnormal noise to occur even when the moment due to the compression reaction force is increased in a scroll compressor.
[0012]
[Means for Solving the Problems]
(1) A scroll type compressor according to claim 1 comprises a fixed scroll comprising a fixed side plate and a fixed spiral provided integrally with the fixed side plate, and a movable scroll provided integrally with the movable side plate and the movable side plate. A movable scroll that is supported so as to be non-rotatable and revolvable in opposition to the fixed scroll, and a compression chamber formed between the fixed scroll and the movable scroll is based on the revolution of the movable scroll. In a scroll compressor that compresses a fluid in the compression chamber by reducing the volume,
The movable scroll has an overall center of gravity set so that a moment due to a compression reaction force of the fluid in the compression chamber is offset as much as possible by a moment due to a centrifugal force.
[0013]
(2) The scroll-type compressor according to claim 2 comprises a fixed scroll comprising a fixed side plate and a fixed spiral provided integrally with the fixed side plate, and a movable side plate and a movable scroll provided integrally with the movable side plate. A movable scroll that is supported so as to be non-rotatable and revolvable in opposition to the fixed scroll, and a compression chamber formed between the fixed scroll and the movable scroll is based on the revolution of the movable scroll. In a scroll compressor that compresses a fluid in the compression chamber by reducing the volume,
The center of gravity of the entire movable scroll is set so as to cancel the first-order component obtained by Fourier-expanding the moment due to the compression reaction force of the fluid in the compression chamber by the rotation moment due to the centrifugal force of the movable scroll. And
[0014]
(3) The method of manufacturing a scroll compressor according to claim 3, wherein the shape of the movable scroll, the shape of the movable side plate provided integrally with the movable scroll, and the position of the movable scroll on the movable side plate are determined. Is temporarily set to determine the temporary center of gravity of the entire movable scroll, and the crank center of a crank pin that is radially separated from the drive center axis of the drive shaft by the revolving radius from the drive center axis to drive the movable scroll. A first step of setting an axis,
The relationship between the magnitude of the moment by the compression reaction force determined by the shape of the movable spiral body and the rotation angle of the drive shaft, and the relationship between the magnitude of the moment by the centrifugal force determined by the temporary center of gravity and the rotation angle of the drive shaft A second step of determining the relationship;
The relationship between the magnitude of the rotation moment determined by the compression reaction force and the centrifugal force and the rotation angle of the drive shaft is determined, and the amplitude and the magnitude of the centrifugal force are set so that the amplitude of the rotation moment becomes a minimum value. And a third step of setting the center of gravity of the entire movable scroll so that the true center of gravity of the entire movable scroll has the changed amplitude and phase difference of the centrifugal force. I do.
[0015]
(4) The method for manufacturing a scroll compressor according to claim 4, wherein the shape of the movable scroll, the shape of the movable side plate provided integrally with the movable scroll, and the position of the movable scroll on the movable side plate are determined. And a first step of setting a drive center axis of the drive shaft and a crank center axis of a crank pin that is radially separated from the drive center axis by an orbital radius and drives the movable scroll. A second step of determining the relationship between the magnitude of the moment due to the compression reaction force determined by the shape of the movable spiral body and the rotation angle of the drive shaft;
A first-order component obtained by Fourier-expanding the moment due to the compression reaction force is calculated, and the relationship between the magnitude of the moment due to centrifugal force and the rotation angle of the drive shaft is calculated to cancel the first-order component. A third step of setting the center of gravity of the entire movable scroll so that the center of gravity has a relationship based on the centrifugal force.
[0016]
(5) The method for manufacturing a scroll compressor according to claim 5 is the method for manufacturing a scroll compressor according to claim 3 or 4, wherein the setting of the center of gravity of the entire movable scroll in the third step is performed by adding a thickness to the movable side plate. It is characterized by being sashimi or stealing.
[0017]
[Action]
(1) In the scroll compressor according to the first aspect, a moment due to centrifugal force is generated around the central axis of the crank by setting the center of gravity of the entire movable scroll. And, even if the movable scroll tries to rotate around the crank center axis due to the moment due to the compression reaction force, the moment due to the centrifugal force cancels the moment due to the compression reaction force as much as possible, so the movable scroll moves along the crank center axis. It is difficult to rotate as the center.
[0018]
For this reason, it is difficult for two places of the contact lines that define the compression chamber to separate from each other, the sealing performance of the compression chamber is secured, and fluid leakage hardly occurs. In addition, the support point that supports the moment due to the compression reaction force is difficult to move.
(2) In the scroll compressor according to the second aspect, a moment due to centrifugal force is generated around the central axis of the crank by setting the center of gravity of the entire movable scroll. And even if the movable scroll tries to rotate around the crank center axis due to the moment due to the compression reaction force, the movable scroll moves along the crank center axis because the primary component obtained by Fourier-expanding the moment due to the compression reaction force is canceled by the moment due to the centrifugal force. It is difficult to rotate as the center.
[0019]
Therefore, similarly to the scroll compressor of the first aspect, fluid leakage hardly occurs, and the support point is hard to move.
(3) In the manufacturing method according to claim 3, first, in the first step, the shape of the movable scroll in the movable scroll, the shape of the movable side plate, and the position of the movable scroll on the movable side plate are provisionally set, and the movable scroll is moved. Determine the temporary center of gravity of the entire scroll. Further, a drive center axis of the drive shaft and a crank center axis of a crank pin for driving the movable scroll are set. The crank center axis is radially separated from the drive center axis by the revolution radius.
[0020]
Next, in the second step, the relationship between the magnitude of the moment due to the compression reaction force determined by the shape of the fixed spiral and the shape of the movable spiral and the rotation angle of the drive shaft, and the centrifugal force determined by the temporary center of gravity And the relationship between the magnitude of the moment and the rotation angle of the drive shaft are determined.
Thereafter, in a third step, the relationship between the magnitude of the rotation moment determined by the compression reaction force and the centrifugal force and the rotation angle of the drive shaft is determined, and the centrifugal force is set so that the amplitude of the rotation moment becomes the minimum value. Change the amplitude and the phase difference. Then, the true center of gravity of the entire movable scroll is set so as to have the changed amplitude and phase difference of the centrifugal force.
[0021]
In the scroll compressor thus obtained, the true center of gravity of the entire movable scroll is set in order to achieve the effect of the first aspect.
(4) In the manufacturing method according to claim 4, first, in the first step, the shape of the movable scroll in the movable scroll, the shape of the movable side plate, and the position of the movable scroll on the movable side plate are provisionally set. Further, a drive center axis of the drive shaft and a crank center axis of a crank pin for driving the movable scroll are set. The crank center axis is radially separated from the drive center axis by the revolution radius.
[0022]
Next, in the second step, the relationship between the magnitude of the moment due to the compression reaction force determined by the shape of the fixed spiral and the shape of the movable spiral and the rotation angle of the drive shaft is determined.
Thereafter, in a third step, a first-order component is calculated by Fourier-expanding the moment due to the compression reaction force. Then, in order to cancel the primary component, the relationship between the magnitude of the moment due to the centrifugal force and the rotation angle of the drive shaft is calculated. Next, a true center of gravity of the orbiting scroll is set so as to have a relationship based on the centrifugal force.
[0023]
In the scroll compressor thus obtained, the true center of gravity of the entire movable scroll is set in order to achieve the effect of the second aspect.
(5) In the manufacturing method of the fourth aspect, the center of gravity of the entire movable scroll is set by overlaying or stealing the movable side plate. In this case, the setting of the center of gravity is easy.
[0024]
【Example】
Hereinafter, Examples 1 to 4 that embody the invention of Claims 1 to 5 will be described with reference to the drawings.
(Example 1)
In the first embodiment, claims 1, 3, and 5 are embodied.
[0025]
"First step"
First, the shape of the movable scroll in the movable scroll is determined by known means. That is, a spiral center Q is set at the origin of the (x, y) orthogonal coordinates shown in FIG. 1, and a base circle (not shown) having a radius A is assumed at the spiral center Q. The distance from a point on the base circle is r, the angle of extension is θ, and the starting point on the base circle on the horizontal axis x of the (r, θ) polar coordinate is made to coincide with the (x, y) rectangular coordinates.
r = A · θ
Is drawn to the final extension angle. Next, a second involute curve is drawn outward from the first involute curve by the revolution radius R. In addition, a third involute curve is drawn by inverting the second involute curve to a position symmetrical with respect to the spiral center Q. Then, the start point on the first involute curve and the start point on the third involute curve are smoothly connected by an arc and a straight line, and the end point on the first involute curve is connected to the third involute curve by a normal. Then, the shape of the movable scroll 1 is determined.
[0026]
Further, by drawing a circle inscribed from the spiral center Q to the outer peripheral end of the movable spiral body 1, the shape of the movable side plate 2 provided integrally with the movable spiral body 1 is determined to be a concentric disk shape, and The position of the movable scroll 1 is provisionally set.
At this time, the center of gravity G of the movable side plate 2₁Corresponds to the center of the spiral, that is, the center axis Q of the movable side plate 2, but the center of gravity G of the movable spiral 1₂Is separated from the center axis Q of the movable side plate 2 and the center of gravity G₁, G₂The temporary center of gravity G of the entire movable scroll 3 at a position other than₀Is determined.
[0027]
Next, as shown by the (X, Y) orthogonal coordinates in FIG. 2, the drive center axis O of the drive shaft and the crank center axis P of the crank pin for driving the movable scroll 3 are set. The crank center axis P is radially separated from the drive center axis O by the revolution radius R. At this time, the origin of the (r, θ) polar coordinate, that is, the center axis Q of the movable side plate 2 is made to coincide with the crank center axis P (see FIG. 1).
[0028]
"Second step"
Next, as shown in FIG. 1, the rotation angle Φ (°) of the drive shaft is determined from the vertical axis y of the (r, θ) polar coordinate. Then, the relationship between the magnitude M (N · m) of the moment Mp around the crank axis P due to the compression reaction force and the rotation angle Φ (°) of the drive shaft is determined. The relationship due to the compression reaction force is determined by the shape of the fixed scroll and the shape of the movable scroll 1. The fixed scroll of the fixed scroll is shifted by 180 ° from the phase of the movable scroll 1 of the movable scroll 3. Because it is defined, it is required as follows.
[0029]
That is, the initial closed volume of the compression chamber formed by the fixed scroll and the movable scroll 3 is V₀, The suction pressure_sAssuming that the specific heat ratio is κ, the closed volume of the compression chamber whose volume is decreasing is V, and the internal pressure is p, Equation 1 is established by adiabatic compression.
[0030]
(Equation 1)

[0031]
Then, assuming a point on the inner wall surface of the movable spiral body 1 forming the compression chamber and defining a unit vector as shown in Equation 2, the force acting on that point will be expressed by the inner area of the compression chamber as S. By this, it is expressed by Expression 3.
[0032]
(Equation 2)

[0033]
(Equation 3)

[0034]
Therefore, the moment Mp due to the compression reaction force is expressed by Equation 4.
[0035]
(Equation 4)

[0036]
FIG. 3 is a graph showing the relationship between the magnitude M (N · m) of the moment Mp due to the compression reaction force and the rotation angle Φ (°) of the drive shaft. In the scroll compressor in which the crank center axis P and the center of gravity G of the entire orbiting scroll are axially coincident with each other as in the technique described in the above publication, a large amplitude of the compression reaction force tends to cause power loss and abnormal noise. It was.
[0037]
Further, the relationship between the magnitude (N · m) of the moment Mc around the crank axis P due to the centrifugal force and the rotation angle Φ (°) of the drive shaft is obtained. The relationship by the centrifugal force is as shown in FIG.₀Is determined as follows.
That is, in this scroll compressor, as shown by the (X, Y) orthogonal coordinates in FIG. 2, when the driving force F acts on the crank center axis P by the rotation of the driving shaft, the movable scroll is formed by the torque FR. The orbit is driven. At this time, the centrifugal force C₁, C₂... is the temporary center of gravity G₀Act in the centrifugal direction from the drive center axis O, but in this scroll compressor, the temporary center of gravity G₀Does not coincide with the crank center axis P. Therefore, the temporary center of gravity G₀R between the motor and the drive center axis O₁, R₂... changes sinusoidally according to the change of the rotation angle Φ (°), and the centrifugal force C₁, C₂... is the distance R₁, R₂It changes sinusoidally according to. Therefore, as shown in FIG. 4, the centrifugal force C is expressed in (X ', Y') orthogonal coordinates with the crank center axis P as the origin.₁, C₂If the vector of ... is enlarged and mapped, the centrifugal force C₁, C₂Are generated around the crank axis P and the centrifugal force C₁, C₂It can be seen that the moment Mc changes sinusoidally according to the rotation angle Φ (°).
[0038]
Therefore, the moment Mc due to the centrifugal force is represented by Equation 5 if the amplitude is a ', the phase difference is φ', and the constant is b '.
[0039]
(Equation 5)

[0040]
"Third step"
When the sum of the moment Mp due to the compression reaction force and the moment Mc due to the centrifugal force for each rotation angle Φ (°) is obtained, this is the rotation moment Mm.
Next, the amplitude a ′, the phase difference φ ′, and the constant b ′ of the moment Mc are changed so that the amplitude of the rotation moment Mm becomes the minimum value. The changed amplitude is a, the phase difference is φ, the constant is b, and the position of the true center of gravity G on the (x, y) orthogonal coordinates in FIG._G, Y_GIf the mass of the orbiting scroll is m and the angular velocity of the drive shaft is ω, Equations 6 and 7 are established from FIG.
[0041]
(Equation 6)

[0042]
(Equation 7)

[0043]
Then, the obtained coordinates (x_G, Y_G) Overlaying or stealing is performed on the back surface of the movable side plate 2 so that the true center of gravity G of the entire movable scroll 3 comes above. FIG. 1 shows the true center of gravity G.
In the scroll compressor thus obtained, a moment Mc due to centrifugal force is generated around the crank axis P by setting the true center of gravity G of the entire movable scroll 3. Even if the movable scroll 3 attempts to rotate around the crank axis P due to the moment Mp due to the compression reaction force, the moment Mc due to the centrifugal force cancels the moment Mp due to the compression reaction force as much as possible. No. 3 is hard to rotate around the crank center axis P.
[0044]
That is, in this scroll compressor, as shown in FIG. 3, the rotation moment Mm has a smaller amplitude than the moment Mp due to the compression reaction force by ΔM. Therefore, in this scroll compressor, two of the contact lines that partition the compression chamber are unlikely to separate from each other, the sealing performance of the compression chamber is ensured, and fluid leakage hardly occurs. Further, the support point that supports the moment Mp due to the compression reaction force is difficult to move.
[0045]
Therefore, this scroll compressor is unlikely to cause power loss and abnormal noise even when the moment Mp due to the compression reaction force increases due to high speed rotation, high compression ratio, and the like.
(Example 2)
In the second embodiment, claims 2, 3, and 5 are embodied.
[0046]
"First step"
First, as in the first embodiment, as shown in FIGS. 1 and 2, the shape of the movable scroll 1 in the movable scroll 3, the shape of the movable side plate 2, and the position of the movable scroll 1 on the movable side plate 2 are described. Set temporarily.
Further, a drive center axis O of the drive shaft and a crank center axis P of a crankpin for driving the orbiting scroll 3 are set.
[0047]
"Second step"
Next, as in the first embodiment, the magnitude M (N · m) of the moment Mp due to the compression reaction force determined by the shape of the fixed spiral body and the shape of the movable spiral body 1 and the rotation angle Φ (° ) And the relationship. FIG. 6 shows the moment Mp due to the compression reaction force.
"Third step"
Thereafter, the moment Mp is Fourier-transformed by substituting the moment Mp into f (x) in Expression 8.
[0048]
(Equation 8)

[0049]
The coefficients up to the tenth order component of the Fourier series are shown in FIG.
The period of the moment Mp due to the compression reaction force is 2π (rad), that is, 180 (°), and the period of the moment Mc due to the centrifugal force is also 2π (rad), that is, 180 (°). Therefore, canceling out the primary component of the rotation angle out of the moment Mp due to the compression reaction force is effective in reducing the moment Mp. This is supported by the fact that the coefficients after the second-order component are small as shown in FIG.
[0050]
Therefore, the primary component Mp 'obtained by Fourier-expanding the moment Mp due to the compression reaction force is given by Expression 9.
[0051]
(Equation 9)

[0052]
Here, a 'is an amplitude,?' Is a phase difference, and b 'is a constant.
Then, the amplitude a ′ in Equation 9 is set to −a ′, and the moment Mc due to the centrifugal force that completely cancels the moment Mp ′ is calculated as in Equation 10.
[0053]
(Equation 10)

[0054]
The primary component Mp 'obtained by Fourier-expanding the moment Mp due to the compression reaction force obtained by the shape of the movable spiral body 1 of Example 2 was represented by Formula 11.
[0055]
(Equation 11)

[0056]
Next, overlaying or stealing is performed on the movable side plate 2 so that the true center of gravity G of the movable scroll 1 has a centrifugal force relationship of several tens.
Note that the true center of gravity G (x_G, Y_G) Satisfies Equations 12 and 13. Here, the mass of the movable scroll is m, and the angular velocity of the drive shaft is ω.
[0057]
(Equation 12)

[0058]
(Equation 13)

[0059]
In the scroll compressor thus obtained, as shown in FIG. 8, the rotation moment Mm is canceled out by the moment Mc due to the true center of gravity G, and as a result, the amplitude is smaller than the moment Mp due to the compression reaction force. For this reason, the same operation and effect as in the first embodiment can also be obtained in this scroll compressor.
(Example 3)
In the third embodiment, the shapes of the movable spiral body 1 and the fixed spiral body are determined by a curve that gradually decreases with an increase in the expansion angle θ from the involute curve. Other configurations are the same as those of the first embodiment.
[0060]
That is, a spiral center Q is set at the origin of the (x, y) orthogonal coordinates shown in FIG. 9 and a base circle (not shown) having a radius A is assumed at the spiral center Q. Then, the distance from a point on the base circle is r, the angle of extension is θ, the positive constant is B, the order of 2 or more is n, and (r, θ) polar coordinates are made to match the (x, y) rectangular coordinates. From the starting point on the base circle on the horizontal axis x of
r = A · θ-Bθⁿ
Is drawn until the final extension angle. Next, a second curve is drawn outward from the first curve by the revolution radius R. In addition, a third curve is drawn by inverting the second curve to a position symmetrical with respect to the spiral center Q. Then, the start point on the first curve and the start point on the third curve are smoothly connected by an arc and a straight line, and the end point on the first curve is connected to the third curve by a normal line. The shape of the body 1 is determined.
[0061]
With the shape and the like of the movable spiral body 1 determined in this way, it has become clear that the true center of gravity G should be at the position shown in FIG. In this scroll compressor, the same operation and effect as those of the first embodiment can be obtained.
(Example 4)
In the fourth embodiment, the shapes of the movable scroll 1 and the fixed scroll are determined by the Archimedes curve. Other configurations are the same as those of the first embodiment.
[0062]
That is, the spiral center Q is set at the origin of the (x, y) orthogonal coordinates shown in FIG.
r = A · θ
Draw the first Archimedes curve to the final extension angle. Here, A is a positive constant, r is the distance from the spiral center Q, and θ is the angle of expansion from the horizontal axis x when the (r, θ) polar coordinate is matched with the (x, y) rectangular coordinate. . Next, a second Archimedes curve is drawn away from the first Archimedes curve by an orbital radius R outward. Further, a third Archimedes curve is drawn by inverting the second Archimedes curve to a position symmetrical with respect to the spiral center Q. Then, a certain point on the first Archimedes curve and a certain point on the third Archimedes curve are smoothly connected by an arc and a straight line, and the end point on the first Archimedes curve is connected to the third Archimedes curve by a normal line. To determine the shape of the movable scroll 1.
[0063]
With the shape of the movable scroll 1 determined in this way, it is clear that the true center of gravity G should be at the position shown in FIG. In this scroll compressor, the same operation and effect as those of the first embodiment can be obtained.
[0064]
【The invention's effect】
As described in detail above, the scroll-type compressors according to the first and second aspects adopt the configuration according to the first and second aspects, so that power loss and abnormal noise hardly occur.
Further, if the method for manufacturing a scroll compressor according to claims 3 to 5 is adopted, the scroll compressor according to claims 1 and 2 can be manufactured.
[Brief description of the drawings]
FIG. 1 is a plan view of a movable scroll according to a first embodiment.
FIG. 2 is orthogonal coordinates schematically showing a position of a drive center axis of a drive shaft, a position of a crank center axis, and the like according to the first embodiment.
FIG. 3 is a graph showing a relationship between a magnitude of a moment and a rotation angle of a drive shaft according to the first embodiment.
FIG. 4 is a vector diagram showing a centrifugal force around a crank central axis according to the first embodiment.
FIG. 5 is an enlarged view of FIG. 1 according to the first embodiment.
FIG. 6 is a graph showing the relationship between the magnitude of the moment due to the compression reaction force and the magnitude of the first-order component of the Fourier series and the rotation angle of the drive shaft according to the second embodiment.
FIG. 7 is a graph showing a relationship between a magnitude and an order in a moment due to a compression reaction force according to the second embodiment.
FIG. 8 is a graph showing the relationship between the magnitude of the moment due to the compression reaction force and the magnitude of the rotation moment and the rotation angle of the drive shaft according to the second embodiment.
FIG. 9 is a plan view of a movable scroll according to the third embodiment.
FIG. 10 is a plan view of a movable scroll according to the fourth embodiment.
FIG. 11 is orthogonal coordinates schematically showing a position of a drive center axis of a drive shaft, a position of a crank center axis, and the like according to a conventional example.
FIG. 12 is a plan view showing a fixed scroll and a movable scroll of a general scroll compressor.
[Explanation of symbols]
3 movable scroll 2 movable side plate 1 movable scroll
Mp: Moment due to compression reaction force Mc: Moment due to centrifugal force
G ... true center of gravity G₀… Temporary center of gravity O… Drive center axis
R: Revolution radius P: Crank center axis Φ: Rotation angle
Mm: rotation moment a, a ': amplitude φ, φ': phase difference

Claims (5)

A fixed scroll composed of a fixed side plate and a fixed scroll provided integrally with the fixed side plate, and a movable scroll provided with a movable side plate and a movable scroll integrally provided with the movable side plate. A movable scroll that is supported so as to be able to compress the fluid in the compression chamber by reducing the volume of the compression chamber formed between the fixed scroll and the movable scroll based on the revolution of the movable scroll. Scroll type compressor,
The scroll type compressor according to claim 1, wherein the movable scroll has an overall center of gravity set so that a moment due to a compression reaction force of the fluid in the compression chamber is offset as much as possible by a moment due to a centrifugal force. A fixed scroll composed of a fixed side plate and a fixed scroll provided integrally with the fixed side plate, and a movable scroll provided with a movable side plate and a movable scroll integrally provided with the movable side plate. A movable scroll that is supported so as to be able to compress the fluid in the compression chamber by reducing the volume of the compression chamber formed between the fixed scroll and the movable scroll based on the revolution of the movable scroll. Scroll type compressor,
The movable scroll has an overall center of gravity set by a moment due to a centrifugal force of the movable scroll to cancel a Fourier-developed primary component of a moment due to a compression reaction force of the fluid in the compression chamber. Scroll type compressor. The shape of the movable scroll, the shape of the movable side plate provided integrally with the movable scroll, and the position of the movable scroll on the movable side plate are temporarily set to determine the temporary center of gravity of the entire movable scroll. A first step of setting a drive center axis of the drive shaft and a crank center axis of a crank pin that is radially separated from the drive center axis by an orbital radius and drives the movable scroll;
The relationship between the magnitude of the moment by the compression reaction force determined by the shape of the movable spiral body and the rotation angle of the drive shaft, and the relationship between the magnitude of the moment by the centrifugal force determined by the temporary center of gravity and the rotation angle of the drive shaft A second step of determining the relationship;
The relationship between the magnitude of the rotation moment determined by the compression reaction force and the centrifugal force and the rotation angle of the drive shaft is determined, and the amplitude and the magnitude of the centrifugal force are set so that the amplitude of the rotation moment becomes a minimum value. And a third step of setting the center of gravity of the entire movable scroll so that the true center of gravity of the entire movable scroll has the changed amplitude and phase difference of the centrifugal force. Of manufacturing scroll type compressor. The shape of the movable spiral body, the shape of the movable side plate provided integrally with the movable spiral body, and the position of the movable spiral body on the movable side plate are temporarily set, and the drive center axis of the drive shaft; A first step of setting a crank center axis of a crank pin that is radially separated from the center axis by an orbital radius and that drives the orbiting scroll;
A second step of obtaining a relationship between a magnitude of a moment due to a compression reaction force determined by a shape of the movable spiral body and a rotation angle of the drive shaft;
A first-order component obtained by Fourier-expanding the moment due to the compression reaction force is calculated, and the relationship between the magnitude of the moment due to centrifugal force and the rotation angle of the drive shaft is calculated to cancel the first-order component. A third step of setting the center of gravity of the entire movable scroll so that the center of gravity has a relationship due to the centrifugal force. The method for manufacturing a scroll compressor according to claim 3 or 4, wherein the setting of the center of gravity of the entire movable scroll in the third step is overlaying or stealing the movable side plate.

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