Patent ID: 7614859
Filing Date: 2009-11-10
Classification: F04C

Abstract:
1. A scroll compressor wherein a fixed scroll having a fixed scroll wrap on a fixed mirror plate and an orbiting scroll having an orbiting scroll wrap on an orbiting mirror plate are combined with each other to form a plurality of compressed chambers, a back pressure chamber is provided on a surface on the opposite side from said orbiting scroll wrap surface of said orbiting scroll, a suction space is formed in an outer periphery of said fixed scroll, said back pressure chamber is divided by an annular seal into an inner region and an outer region, a lubricant oil in a discharge pressure state is supplied to said inner region of said annular seal, a portion of the lubricant oil is decompressed at a narrowed portion and supplied to said outer region, the lubricant oil in the outer region is supplied to said suction space, pressure in said inner region is set to discharge pressure Pd, pressure in said outer region is set to a predetermined pressure Pm between a suction pressure Ps and a discharge pressure Pd, thrust force is applied to a back surface of said orbiting scroll, thereby bringing said orbiting scroll into contact with said fixed scroll, rotation of said orbiting scroll is restrained by a rotation-restraint member, said orbiting scroll is allowed to orbit, thereby moving said compressed chamber toward a center of scroll while reducing its volume, refrigerant gas is sucked from the suction space into said compressed chamber and compressed, a pressure ratio (Pd/Ps) between the discharge pressure Pd and the suction pressure Ps is set to 2 to 6, and a ratio (d/D) of a diameter D of said orbiting mirror plate of said orbiting scroll and an outer diameter d of said annular seal is set greater than 0.5.