Abstract: A scroll compressor comprising a housing, a frame, a fixed scroll and an orbiting scroll, arranged in the housing. Each of the fixed and orbiting scrolls have an end plate and a spiral wrap. A bearing boss is formed on the back surface of the end plate of said orbiting scroll. A plurality of radial ribs are formed on the back surface of the end plate of said orbiting scroll, with the radial ribs extending from the bearing boss to the marginal side of the end plate of said orbiting scroll.

Abstract: In a scroll compressor having a stationary scroll and a revolving scroll, and a refrigerator incorporating this scroll compressor, the stationary scroll has a gas suction hole formed in its radially outer portion, a gas discharge hole formed in its central portion, and gas injection holes and a liquid injection hole formed between the suction and discharge holes. The gas injection holes are formed in a radially outer portion of the stationary scroll, and the liquid injection hole are formed in a central portion of the stationary scroll. The refrigerator incorporates the scroll compressor, a condenser, decompressors and an evaporator to form a refrigerating circuit. The liquid injection hole of the scroll compressor is directly connected by piping to the outlet of the condenser, and the gas injection holes are connected by piping to the outlet of the condenser through one of the decompressors.

Abstract: A capacity controllable compressor apparatus has a plurality of high-pressure chamber compressors which are connected in parallel to a common refrigerant suction pipe and a common refrigerant discharge pipe, and oil equalizing pipes through which oil sumps of the plurality of compressors are communicated with each other. One of the plurality of compressors is operated with its chamber kept at a higher internal pressure than other compressors.