Oil separator for rotary compressor

Claim 1

A refrigerant compressor comprising a housing having a compression cavity formed therein; suction and discharge ports communicating with said cavity; a rotor in said compression cavity adapted to compress a refrigerant fluid introduced through said suction port and discharge said fluid, together with a liquid lubricant entrained therewith, through said discharge port at a higher pressure; a closed shell having a generally circular cross-section enveloping said housing and spaced therefrom to provide a substantially annular fluid passage between the inside surface of said shell and the outside surface of said housing, said shell having an end wall axially spaced from said housing, said discharge port being located with respect to said shell to deliver the discharge gas directly from said discharge port against the inside surface of said shell whereby a portion of any lubricant entrained in said discharge gas coalesces on said inside surface; a gas permeable coalescing medium arranged within said shell and having its marginal edges closely conforming with the inside diameter of said shell, said coalescing medium being spaced from the end of said shell to provide a partition separating the space enclosed by said shell into first and second chambers such that said housing is located entirely within said first chamber and the discharge gas flows from said annular fluid passage into said first chamber; and a discharge gas conduit having its entrance end located in said second chamber whereby the gas delivered into said second chamber must flow through said coalescing medium to reach said entrance end.