US Patent 7025576 Pump with axial conduit

An air pump including an outer housing and an inner housing positioned within the outer housing, the inner housing and outer housing defining an air conduit therebetween, a motor positioned within the inner housing, a vane occupying a majority of the fluid conduit, and an impeller positioned within the fluid conduit and connected to the motor. The outer housing is adapted to couple to an inflatable bladder. In some embodiments, a majority of the pump and a valve assembly is positioned within the bladder.