US Patent 7568897 Scroll machine with seal

A compressor may include a housing, a compression mechanism supported within the housing, and a seal assembly. The housing may include a suction pressure region and a first discharge passage in communication with a discharge pressure region. The compression mechanism may include a second discharge passage in communication with the first discharge passage. The seal assembly may be sealingly engaged with the housing and the compression mechanism to define a chamber and to provide sealed communication between the first and second discharge passages. The seal assembly may include a seal member engaged with the compression mechanism and including a leg having an opening therein. The leg may isolate the chamber from the discharge pressure region when in a first position and may provide communication between the chamber and the discharge pressure region through the opening when in a second position different than the first position.