Abstract: A pump having centrifugal and vortex impellers mounted on a common rotor member. Impellers are mounted on opposite sides of rotor and make maximum use of rotor diameter. Fluid follows a serial path through the centrifugal and vortex impellers. The vortex impellers rotate in a vortex channel divided into one or more sections, plural sections of which may be arranged in parallel flow relation. The casing surrounding the rotor member may form the necessary inlet, outlet, and internal fluid channels for the pump.

Abstract: A linearly reciprocating fan for cooling a linear motor which drives the fan is disclosed as including a fan blade attached to the linear motor and means for guiding the air flow caused by the reciprocating blade across the linear motor to cool the motor.

Abstract: In an electric motor fan unit, a motor section frame enclosing a motor ventilating fan moving air through an internal motor cooling air path includes an end bracket with an enlarged rim for mounting fan shell and interior partition structures defining a fan section housing with a chamber for a working air centrifugal impeller mounted on the motor shaft outboard of the end bracket and drawing a working air stream into a housing axial inlet for discharge at the housing circumference, and with an inner chamber for a slinger disk on the shaft to afford bearing protection from working air borne moisture, contaminants, and high temperature and humidity, by simple, low cost, durable structure.