Patent ID: 8517704
Filing Date: 2013-08-27
Classification: F04C

Abstract:
1. A compressor comprising: a housing defining a suction pressure region; a first scroll member supported within said housing and including a first end plate defining a capacity modulation passage and having a first spiral wrap extending from said first end plate; a second scroll member supported within said housing and including a second end plate having a second spiral wrap extending therefrom and meshingly engaged with said first spiral wrap to form a suction pocket, a first intermediate compression pocket and a discharge pocket, said capacity modulation passage being in communication with said first intermediate compression pocket; a piston supported on said first scroll member and partially defining a modulation control chamber; a control valve in communication with said modulation control chamber and with first and second pressure sources, said control valve selectively providing communication between said modulation control chamber and one of said first and second pressure sources to displace said piston between a closed position and an open position, said piston isolating said capacity modulation passage from communication with said suction pressure region when in the closed position and providing communication between said capacity modulation passage and said suction pressure region when in the open position; and a seal engaged with said first scroll member, said seal and said first scroll member at least partially defining a biasing chamber in communication with a second intermediate compression pocket formed by said first and second spiral wraps, said control valve being in communication with said biasing chamber and said biasing chamber forming said first pressure source.