CENTRIFUGAL REFRIGERATION COMPRESSOR

摘要

In a centrifugal compressor a sealed annular space is established between the backside of the impeller and the housing wall. Pump means is provided to maintain a minimum pressure in the annular space at a level above the pressure in the bearing structure mounted in the housing wall. The arrangement prevents the passage of oil from the bearing structure to the area behind the impeller when the discharge pressure falls to an abnormally low level.