PURPOSE:To reduce the deflection of a stationary scroll as well as to make it simple to form an oil feed passage to a fluid operating chamber by communicating the chamber with an oil sump within a casing with each other by the use of an oil passage furnished with a squeezing section, and concurrently communicating the bottom section of the chamber with the fluid operating chamber in an intermediate pressure range by the use of an oil feed path. CONSTITUTION:A chamber 7 at the back face of a stationary scroll 2 is communicated with a high pressure oil pump 97 within a hermetic casing 1 through an oil passage 6 furnished with a section squeezed by a main bearing 5. The chamber 7 is concurrently communicated with a fluid operating chamber 4 in an intermediate pressure range through an oil feed path 70. The inner pressure of the chamber 7 is maintained at the pressure which is decreased by a decrement equivalent to the passage squeezed by the main bearing 5 against high pressure, that is, at the intermediate pressure close to pressure within the operating chamber 4, oil is thereby introduced to the chamber 7 out of the oil sump 97, so that oil is therefore fed into the operating chamber 4 from the bottom section of the chamber 7 through the oil feed path 70. In this case, since pressure at the back face side of the scroll 2 falls in the intermediate pressure range, energizing force from the back face is prevented from being excessive, deformation due to the deflection of the scroll 2 can thereby be reduced.
【目的】固定スクロール２のたわみ変形を低減し、且つ 作動流体の加熱を抑制して性能を改善し、しかも流体作 動室４内への油注入のための通路構成を簡易化する。
【構成】可動スクロール３側に吐出穴３４を開口し、固 定スクロール２の背面とボトム１３との間にチャンバー ７を区画して、チャンバー７とモータ９の下部に設ける 高圧の油溜９７との間を、途中部にクランク軸９３の主 軸受５を利用した絞り部をもつ油通路６で連通し、且つ チャンバー７の底部と中間圧力領域にある流体作動室４ との間を油注入路７０で連通し、チャンバー７内を中間 圧力として、固定スクロール２の背面からの付勢力を抑 制し、且つ圧縮ガスの加熱を抑制し、更にチャンバー７ の底部利用により油注入のための通路構成を簡易化し た。