Patent ID: 8337183

Claim:
A scroll compressor comprising: a first scroll member having a base and a generally spiral wrap extending from its base; a second scroll member having a base and a generally spiral wrap extending from its base, said wraps of said first and second scroll members interfitting to define compression chambers, said second scroll member being driven to orbit relative to said first scroll member, and said first scroll member having a discharge port communicating to a check valve chamber having a check valve positioned to selectively close said discharge port; said first and second scroll members being housed within a sealed housing, and a separating member defining a suction chamber which is separated from a discharge chamber, said check valve communicating flow from said discharge port into said discharge chamber; and a oil return path communicating a passage from said discharge chamber, through a valve cavity, into a passage to said suction chamber, a valve spool moveable within said valve cavity, said valve spool having a tap to pressure in said check valve chamber on a first face, and a tap to said discharge chamber on a second face, with said pressure in said check valve chamber acting on said first face to urge said valve spool in a first direction, and said pressure in said discharge chamber acting on said second face to urge said valve spool in a second direction, opposed to said first direction, and said first face having a larger surface area than said second face, such that when said compressor is running, said valve spool is biased to a position allowing communication between said passage from the discharge chamber and said passage to the suction chamber, and said valve spool being biased to close communication between said passage from said discharge chamber and said passage to the suction chamber when the compressor is shut down.