Refrigeration compressor defining oil sump containing an electric lubricant pump

Claim 1

A refrigerant centrifugal compressor comprising: a compressor housing; a shaft disposed within said housing; bearing means for rotatably supporting said shaft in said housing; a centrifugal type fluid impeller disposed within said housing and mounted for rotation with said shaft; an annular inlet member disposed within said housing to conduct fluid to the inlet of said impeller and coaxially arranged with respect to said shaft; a plurality of inlet control vanes disposed in said inlet member; portions of said inlet member being radially inwarDly spaced from said housing thereby defining a substantially annular cavity between and axially coextensive with said compressor housing and said inlet member; a lubrication system for said compressor including first conduit means for conducting lubricant to said bearing means; and second conduit means for draining lubricant from said bearing means to said annular cavity whereby said annular cavity defines as a lubricant sump; means for mechanically adjusting said control vanes disposed within said cavity; passage means for venting the upper portion of said cavity to the inlet of said compressor; and pressurizing means for pressurizing lubricant from said sump and returning pressurized lubricant to said bearing means via said first conduit means.