Immersible pump and motor - has helical coolant slot over rotor surface, rotor driving coolant parallel to shaft axis

摘要

In the immersible pump and motor group, the motor is enclosed in a sealed casing, coupling to the pump is coaxial, the pump also being immersed in the liquid that requires pumping. The motor-pump arrangement is vertical with the pump being uppermost. Cooling is by a heat transporting liquid flowing over the stator, circulation over the rotor being via a helical slot over its surface. Rotor rotation drives the coolant parallel to the motor shaft axis, the return path being via the stator surface. The helix step is between 0.2 and 0.5 times the rotor diameter and slot depth between 0.5 and 1.0 times the air-gap dimension between rotor and stator, its width being 0.1 and 0.2times the helix step length.