MULTISTAGE REGENERATIVE PUMP

PROBLEM TO BE SOLVED: To provide a multistage regenerative pump capable of keeping high accuracy of lamination dimensions of impellers without increasing starting torque of a motor.SOLUTION: The multistage regenerative pump includes: a motor part 2 comprising a motor 5; and a pump part 3 comprising a pump shaft 16 which is stored in pump casings 20-23 and to which rotation of a shaft 10 of the motor 5 is transmitted, and impellers 13-15 attached on a plurality of stages along an axial direction of the pump shaft 16. Each of the impellers 13-15 is composed of a resin material, configured so that a hole 35 is formed on a center and a plurality of blade pieces 37 are formed on an outer peripheral part along a peripheral direction, and fitted and attached through the hole 35 to each of a plurality of sleeves 17-19 which are arranged abutting on the pump shaft 16 in the axial direction and composed of a plurality of metal materials.