Patent ID: 6389837
Filing Date: 2002-05-21
Classification: F04C

Abstract:
A scroll compressor comprising a hermetic shell having an interior partitioned into a refrigerant discharge chamber and a driving chamber by means of a frame plate,said refrigerant discharge chamber having a refrigerant compressing section housed therein and composed of a combination of a fixed scroll and an orbiting scroll, said driving chamber provided with an electric motor for driving the orbiting scroll, the scroll compressor being capable of switching between an internal high-pressure operation mode in which a high-pressure refrigerant generated in said refrigerant compressing section is transferred from said refrigerant discharge chamber through said driving chamber to a predetermined refrigerant circuit and an internal low-pressure operation mode in which the high-pressure refrigerant generated in said refrigerant compressing section is transferred from said refrigerant discharge chamber to said refrigerant circuit and in which a low-pressure refrigerant having completed its work is sucked into said refrigerant compressing section through said driving chamber, and the scroll compressor including a first back pressure chamber arranged between a rear surface of a base plate of said orbiting scroll and said frame plate and which is in communication with said driving chamber to provide pressure from the driving chamber to said base plate of said orbiting scroll as back pressure, the scroll compressor being characterized by further comprising: a second back pressure chamber formed independently of said first back pressure chamber and back pressure control means for varying pressure in said second pressure chamber depending on said operation mode.