Centrifugal pump with an axial-field integral motor cooled by working fluid

An axial-field integral-motor pump, comprising:

• a housing assembly including a pump case with a working fluid inlet and a working fluid discharge, and a motor case with an annular stator socket and an internally threaded blind bore centered within said stator socket, and a stationary shaft mounted in said threaded blind bore;
• a sealed motor stator mounted in said stator socket housing assembly radially surrounding said stationary shaft;
• a means on one of said stator socket and said motor stator for spacing said stator from said stator socket to provide a plurality of channels along said motor stator to permit flow of cooling fluid for cooling said stator;
• a sealed motor rotor axially spaced from said stator and fixed to an impeller having a hub and a bearing fixed in said hub, said impeller being rotatably mounted on said stationary shaft;
• an axial passageway formed within said stationary shaft;
• and
• a means for conducting a portion of the working fluid from said working fluid discharge, along surfaces of said rotor to said plurality of channels along said stator, through said axial passageway within said stationary shaft, to said working fluid inlet.

An axial-field integral-motor pump, comprising:

• a housing assembly having a working fluid inlet, a working fluid discharge, and a stationary shaft mounted therein;
• a motor stator mounted in said housing assembly radially surrounding said stationary shaft and having means for sealing to prevent exposure to said working fluid;
• a motor rotor axially spaced from said stator and fixed to an impeller having a hub and journaled, by a bearing fixed in said hub, on said stationary shaft within said housing assembly, said rotor having means for sealing to prevent exposure to said working fluid;
• an axial passageway formed within said stationary shaft;
• a means for conducting working fluid from said working fluid discharge, along sealed surfaces of said rotor and said stator, to said axial passageway within said stationary shaft, to said working fluid inlet;
• a means for conducting working fluid from said working fluid discharge, through a gap between said stator and said rotor provided by the axial spacing of said rotor from said stator, through grooves in the bearing fixed within said impeller, to said working fluid inlet;
• and
• a means for conducting working fluid from said working fluid discharge, through one or more radial passages between said rotor and said impeller, through a passage in the hub of said impeller, to said working fluid inlet.