Back pressure structure of intermediate pressure of scroll compressor

Abstract

A back pressure structure of a scroll compressor having a fixed scroll forming a plurality of compressive chambers together with an orbiting scroll in its casing; including: a suction pressure space having a predetermined volume formed at one side of the fixed scroll; a suction hole formed for guiding a part of an intermediate gas filled in an intermediate pressure space filled in the rear side of the orbiting scroll to the suction pressure space by passing through the fixed scroll; a vent hole formed at the other side of the suction pressure space for guiding the intermediate pressure gas flown into the suction pressure space through the suction hole to the outermost compressive chamber which has a relatively low pressure; and a back pressure control valve elastically supported by an elastic member in the suction pressure space to open and close the suction hole, and receiving almost the same pressure no matter that it is opened or closed, according to which an intermediate pressure space between a main frame and an orbiting scroll is maintained in a constant intermediate pressure state to thereby prevent an abnormal movement of the orbiting scroll, so that leakage of a compressed gas is prevented, and a position of a suction hole on a fixed scroll is freely selected to be formed, thereby facilitating its fabrication.