To reduce size and weight and improve reliability.

A stator assembly 4 is contained in a rotor assembly. In the rotor assembly, a plurality of protruding electrode permanent magnets 52 are formed on an inner peripheral part and a recessed part axially communicated between the protrusion electrode permanent magnets is formed, and an axial flow passage is composed of the outer peripheral part of the stator assembly and the recessed part. Further, a rotary fan 55 is arranged at the end part of the rotor assembly and a flow straightening plate 12 is arranged on the outside of the end part of the rotor assembly. Further, an oblique flow centrifugal fan 54 is fixed on one end side of a rotary shaft 53. Through rotation of the rotor, liquid is fed in a flow passage from the oblique flow centrifugal fan through a rotary fan and discharged from a flow passage through the flow straightening plate.