2 stage rotary compressor

Abstract

A 2 stage rotary compressor is provided that includes a hermetic container that defines an outward appearance of the compressor; a 2 stage compression assembly provided in the hermetic container, wherein a low pressure cylinder, a middle plate, and a high pressure cylinder are successively stacked from any one of upper and lower portions; and first discharge port that discharges refrigerant compressed in the low pressure cylinder, and having an inner volume equivalent to 0.5% to 2.5% of an inner volume of the low pressure cylinder. A valve is installed on or under the discharge port. When the valve is opened, compressed refrigerant is discharged through the discharge port. When the valve is closed, refrigerant remains in the discharge port as much as the volume of the discharge port. Accordingly, refrigerant remaining in the discharge port is re-expanded in the cylinder, to thereby cause a compression loss. Moreover, in a case in which the volume of the discharge port is excessively small, a resistance occurs in a refrigerant passage. As a result, the volume of the discharge port should he appropriately restricted.