PUMP

PROBLEM TO BE SOLVED: To provide a pump capable of enhancing energy efficiency of a motor. SOLUTION: The pump 1 is equipped with a pump case 3 which includes a motor chamber 7 and pump chamber 5 thereinside and openings of a suction port 9 and delivery port 11 communicating to the pump chamber 5, an impeller 13 freely rotatably arranged in the pump chamber 5, and a motor 21 for rotating the impeller 13. The motor 21 includes a cylindrical rotor 27 arranged in the pump chamber 5 and provided integrally with the impeller 13, and a cylindrical stator 23 provided so as to turn around the outer peripheral side of the rotor 27 through a cylindrical partition wall part 28 which is arranged in the motor chamber 7 and which separates the motor chamber 7 from the pump chamber 5. A plurality of dimples 27d are provided in the outer peripheral surface of the rotor 27. COPYRIGHT: (C)2009,JPO&INPIT