Patent ID: 6422838
Filing Date: 2002-07-23
Classification: F04D

Abstract:
A two-stage, permanent-magnet, integral disk-motor centrifugal pump, comprising:a housing having first and second suction ports and first and second discharge ports, said first discharge port being connected to said second suction port; a first impeller rotatably disposed on a shaft between the first suction port and the first discharge port and a second impeller placed back-to-back with said first impeller and rotatably disposed on a shaft between the second suction port and the second discharge port, each of said first and second impellers having a back shroud with an array of permanent magnets fixed thereto; a first stator and a second stator interposed between and adjacent to said first and second impellers, respectively; means for controlling rotational speed of said impellers; and means for extracting motor heat from the pump, said means comprising a cooling path through which working fluid is directed, said cooling path extending from the discharge of either one of the impellers, between the first and second stators, and back to the suction of either one of the impellers.