Abstract: A sealed submersible electric motor driven centrifugal primary cooling fluid pump is entirely submersible in the electron beam tube cooling system of an X-Ray system incorporates a heat exchanger in the pump, wherein primary cooling fluid (oil or other high dielectric strength fluid) that is pumped in the sealed pump through an annular primary fluid passage therein is cooled by secondary cooling fluid flowing through an annular passage wrapped around the primary fluid annular passage over the length of the primary fluid annular passage, providing a compact unit of pump and heat exchanger.

Abstract: A motor driven centrifugal fluid pump has the a pump rotor, and the pump drive motor both enclosed in a sealed housing that contains sealed inside the fluid that is pumped, the pump rotor being carried on the motor drive shaft so that the rotor rotates freely within the housing when driven by the motor drive shaft, a fluid input from an outside source to the housing, a fluid output to an outside utilization system from the housing and means carried on the motor drive shaft for compelling some of the fluid inside the housing to flow in heat conducting proximity to the motor to cool the motor and also reduce the thrust load on the motor.

Abstract: A magnetically driven centrifugal pump includes a sealed housing enclosing a magnetically driven rotor on an axle of rotation contained within the housing, the axle being attached to the back inside wall of the housing and extending therefrom into the rotor, the rotor having impellers attached to the face thereof toward the front of the housing, the impellers defining radial fluid passages leading from the axial center of the front of the housing to the periphery of the housing and the rotor having radially oriented magnets in the back face thereof for coupling with similarly oriented magnets in an external magnetic drive, whereby the axial dimension of the rotor need be only the width of a radial magnet plus the axial projection of an impeller and the axial dimension of the sealed housing may be only slightly greater than the axial dimension of the rotor and may be substantially less than the radial diameter thereof.