To improve electrical efficiency by reducing a magnetic gap, improve pump efficiency by reducing fluid loss, prevent a rotational part from being slid on the peripheral wall even in idling, prevent abrasion of a rotor caused by slurry, and facilitate internal cleaning by simplifying disassembly and assembly, in a pump having no power shaft and no bearing and for indirectly driving the rotational part.

An impeller 7 is connected to a rotor 4 in a vertical pump structure, and the rotor is constituted of a combination of a nonmagnetic electric conductor and a magnetic substance. A partition wall (a stator can 3) is provided in a rotational magnetic field generating device having the same shape as a general-purpose three-phase motor to prevent oscillation to the rotor by the liquid film effect. A filter 10-1 is provided on the way of a piping 10 for reflux fluid to a discharge port to prevent abrasion of the rotor and the can caused by slurry. Attaching and detaching of an impeller casing 8 is performed by attaching bolts 8-2, and extracting of the rotor and impeller to the outside is facilitated.