High speed fluid pump powered by an integral canned electrical motor

A fluid pump comprising:

• a housing having a generally cylindrical passage extending therethrough;
• a sealed annular stator mounted around said housing, said stator having energizing means for electrically connecting said stator to a source of electrical power;
• an impeller assembly rotatably mounted in said generally cylindrical passage in said housing, said impeller assembly comprising an impeller and a sealed rotor mounted around the perimeter of said impeller and positioned inside said stator to form an electric motor, the operation of which rotates said impeller to produce a pressurized flow of fluid through said generally cylindrical passage in said housing;
• bearing means for rotatably supporting said impeller assembly, said bearing means including a thrust bearing mounted between said perimeter of said impeller and said housing;
• a peripheral fluid circulation channel defined between said housing and said rotor, and in communication with said generally cylindrical passage through said housing through a gap formed between said housing and a downstream peripheral end of said impeller assembly;
• said thrust bearing positioned in said peripheral fluid circulation channel;
• said impeller assembly including a radial flow auxiliary impeller in communication with said peripheral fluid circulation channel and said generally cylindrical passage through said housing for producing fluid flow from said generally cylindrical passage to said peripheral fluid circulation channel to pressurize said peripheral fluid circulation channel;
• a generally hollow shaft centrally positioned in said generally cylindrical passage in said housing and secured to said housing by at least one diffuser vane;
• said impeller assembly rotatably supported by said shaft;
• and
• said shaft having a longitudinally extending shaft passageway therein in communication with said generally cylindrical passage in said housing at a position downstream from said impeller to supply fluid flow from said generally cylindrical passage to said auxiliary impeller.