Patent ID: 7048520

Claim:
A multistage sealed direct drive pump comprising: an electrical motor having a motor shaft having first and second motor shaft ends extending from respective ends of the motor, the motor windings submersible and operative to run in a coolant liquid; a plurality of impellers mounted on the motor shaft and rotatable therewith, at least one of the impellers mounted to a respective one of the first and second motor shaft ends; a sealed housing enclosing the motor and plurality of impellers; electrical leads hermetically sealed to a wall of the housing and electrically connected to the motor for supply of electrical power thereto; a coolant path between the impellers; a coolant liquid inlet connected to the housing for conveying coolant liquid to the input of the plurality of impellers; a coolant liquid outlet connected to the housing for conveying coolant liquid from the output of the plurality of impellers; and a portion of the coolant path circulating around the motor windings.